Digital printing system

This application is based on U.S. Provisional Patent Application No. 62588405, filed on November 19, 2017, and U.S. Provisional Patent Application No. 62595536, filed on December 6, 2017, both of which are incorporated herein by reference in their entirety. It claims the benefit of the issue.

The present invention relates to systems and methods for controlling various aspects of digital printing systems that utilize intermediate transfer members. In particular, the present invention is suitable for printing systems in which fluid is applied to an intermediate transfer member.

Various printing systems use an inkjet printing process in which ink is jetted to form an image on the surface of an intermediate transfer member (ITM), which is then used to transfer the image to a substrate. The ITM may be a rigid drum or a flexible belt (eg, guided over rollers or attached to a rigid drum). In some cases, it is desirable to apply a solution, such as a processing solution, to the surface of the ITM in order to improve the quality of the image printed on the surface of the ITM and transferred from there to the substrate. The solution may be applied in excess of the final desired thickness, in which case a doctor blade may be used to remove the excess. Such doctor blades need to be cleaned from time to time during operation of the printing press to ensure accurate and continuous application of the solution. In order to facilitate cleaning of the blades, it may be advantageous to change the blades from time to time, preferably only according to instructions executed by a blade change controller.

The following co-pending patent publications, WO/2017/009722 (PCT/IB2016/053049 filed on May 25, 2016), WO/2016/166690 (published on April 4, 2016), PCT/IB2016/052120 (filed on March 20, 2016), WO/2016/151462 (PCT/IB2016/051560 filed on March 20, 2016), WO/2016/113698 (January 2016) PCT/IB2016/050170 filed on January 14), WO/2015/110988 (PCT/IB2015/050501 filed on January 22, 2015), WO/2015/036812 ( PCT/IB2013/002571 filed on September 12, 2013), WO/2015/036864 (PCT/IB2014/002366 filed on September 11, 2014), WO/2015 /036865 (publication of PCT/IB2014/002395 filed on September 11, 2014), WO/2015/036906 (publication of PCT/IB2014/064277 filed on September 12, 2014) , WO/2013/136220 (publication of PCT/IB2013/051719 filed on March 5, 2013), WO/2013/132419 (PCT/IB2013/051717 filed on March 5, 2013) WO/2013/132424 (PCT/IB2013/051727 filed on March 5, 2013), WO/2013/132420 (PCT filed on March 5, 2013) /IB2013/051718), WO/2013/132439 (PCT/IB2013/051755 filed on March 5, 2013), WO/2013/132438 (published on March 5, 2013), PCT/IB2013/051751 filed on March 5, 2013), WO/2013/132418 (PCT/IB2013/051716 filed on March 5, 2013), WO/2013/132356 (January 2013) PCT/IB2013/050245 filed on March 10, 2013), WO/2013/132345 (PCT/IB2013/000840 filed on March 5, 2013), WO/2013/132339 (Publication of PCT/IB2013/000757 filed on March 5, 2013), WO/2013/132343 (Publication of PCT/IB2013/000822 filed on March 5, 2013), WO/ No. 2013/132340 (publication of PCT/IB2013/000782 filed on March 5, 2013), and WO/2013/132432 (publication of PCT/IB2013/051743 filed on March 5, 2013). Publications) may provide related background material, all of which are incorporated herein by reference in their entirety.

The following co-pending applications, PCT application No. PCT/IB2017/053177 filed on May 30, 2017, and PCT application No. PCT/IL2017/050616 filed on June 1, 2017, all This application is incorporated by reference in its entirety.

<p>The present disclosure describes a moving intermediate transfer member, such as a flexible ITM (e.g., a blanket) mounted on a plurality of rollers (e.g., a belt) or mounted on a rigid drum (e.g., a drum-mounted blanket). (ITM) and its operating method.</p><p>An ink image is formed on the surface of a moving ITM (eg, by droplet deposition at an imaging station) and then transferred to a substrate, which may comprise paper, plastic, metal, or any other suitable material. To transfer the ink image to the substrate, the substrate is pressed between at least one impression cylinder and the area of the moving ITM where the ink image is located, at a transfer station (also referred to as an impression station). are said to be engaged.</p><p>In the case of a flexible ITM mounted on multiple rollers, the impression station generally comprises a pressure cylinder or roller in addition to the impression cylinder, the outer surface of which may optionally be compressible. A flexible blanket or belt generally passes between two such cylinders that can be selectively engaged or disengaged as the distance between the two cylinders decreases or increases. One of the two cylinders may be in a fixed position in space and the other may move towards or away from it (e.g. the pressure cylinder is movable or the impression cylinder is movable), or the two cylinders may each be moved towards or away from each other. Or you can move away. In the case of a rigid ITM, the drum (optionally on which a blanket may be placed) constitutes a second cylinder that engages or disengages the impression cylinder.</p><p>For clarity, the term rotation is used herein to refer to whether the motion is locally linear, locally rotational, or otherwise at various locations within the printing press. Regardless, it is used to describe the movement of the ITM within the printing press in the printing direction. For rigid ITMs with a drum shape or drum support, the movement of the ITM is rotational. The printing direction is determined by the movement of the ink image from the imaging station to the impression station. Unless the context indicates otherwise, the terms upstream and downstream as they may be used below refer to position relative to the printing direction.</p><p>Some embodiments relate to a printing system, and in particular, the printing system includes an intermediate transfer belt that includes a flexible endless belt resting on a plurality of guide rollers and also includes a first and a second plurality of predetermined portions. a member (ITM), an imaging station configured to form an ink image on a surface of the ITM, and driving rotation of the ITM to transport the ink image toward an impression station where the ink image is transferred to a substrate. and a processing station configured to coat the ITM surface with a layer of processing liquid, the processing station being configured to coat the ITM with a layer of processing liquid. and a coating thickness adjustment assembly comprising a plurality of blades, each one of the blades at least part of the time so as to leave only the desired layer of treatment agent; a coating thickness adjustment assembly configured to traverse the fixed surplus removal position and be in an active position for removing excess liquid from that portion of the ITM, and a blade associated with the coating thickness adjustment assembly and in the active position; a blade exchange mechanism configured to perform a blade exchange operation to exchange the ITM with another blade; and a blade exchange mechanism configured to perform a blade exchange operation to exchange the ITM with another blade; and a blade exchange controller for controlling the blade exchange mechanism to ensure that the blade exchange mechanism is</p><p>In some embodiments, the printing system includes an intermediate transfer member (ITM) that includes a flexible endless belt disposed over a plurality of guide rollers (ITM includes a first and a second plurality of predetermined portions). ), an imaging station configured to form an ink image on a surface of the ITM, and rotation of the ITM to transport the ink image toward an impression station where the ink image is transferred to a substrate. and a processing station configured to coat the ITM surface with a layer of treatment liquid, the processing station being configured to coat the ITM surface with a layer of treatment liquid, the processing station being configured to coat the ITM surface with a layer of treatment liquid, the processing station being configured to coat the ITM surface with a layer of treatment liquid. a coating thickness adjustment assembly comprising: an applicator for applying a treatment solution to the surface; and a coating thickness adjustment assembly comprising a plurality of blades, each one of the blades at least part of the time leaving only a desired layer of treatment solution; a coating thickness adjustment assembly configured to be in an active position for removing excess liquid; and a blade exchange operation associated with the coating thickness adjustment assembly to replace the blade in the active position with another blade. a blade changing mechanism configured to perform and controlling the blade changing mechanism to ensure that a blade changing operation occurs only when one of the first plurality of predetermined portions of the ITM traverses the surplus removal position; A blade exchange controller may be provided for the blade exchange.</p><p>In some embodiments, the printing system includes an intermediate transfer member (ITM) that includes a flexible endless belt disposed over a plurality of guide rollers (ITM includes a first and a second plurality of predetermined portions). ), an imaging station configured to form an ink image on a surface of the ITM, and rotation of the ITM to transport the ink image toward an impression station where the ink image is transferred to a substrate. and a treatment station configured to apply a layer of treatment liquid to the ITM surface, the treatment station being configured to apply a layer of treatment liquid to the ITM surface, the treatment station being positioned downstream of the impression station and upstream of the imaging station. an applicator for applying a treatment solution to a coating material, and a coating thickness adjustment assembly comprising a plurality of blades, the coating thickness adjustment assembly having a plurality of blades that each one may be configured to be in an active position for removing excess liquid from that portion of the ITM when the ITM portion traverses a fixed surplus removal position) and associated with a coating thickness adjustment assembly; a blade changing mechanism configured to perform a blade changing operation to replace a blade in the ITM with another blade; and a blade changing mechanism configured to perform a blade changing operation when one of the second plurality of predetermined portions of the ITM traverses the surplus removal location. and a blade exchange controller for controlling the blade exchange mechanism to avoid the blade exchange mechanism.</p><p>In some embodiments, the printing system includes an intermediate transfer member (ITM) that includes a flexible endless belt disposed over a plurality of guide rollers (ITM includes a first and a second plurality of predetermined portions). ), an imaging station configured to form an ink image on a surface of the ITM, and rotation of the ITM to transport the ink image toward an impression station where the ink image is transferred to a substrate. and a treatment station configured to apply a layer of treatment liquid to the ITM surface, the treatment station being configured to apply a layer of treatment liquid to the ITM surface, the treatment station being positioned downstream of the impression station and upstream of the imaging station. an applicator for applying a treatment solution to a coating material, and a coating thickness adjustment assembly comprising a plurality of blades, the coating thickness adjustment assembly having a plurality of blades that each one may be configured to be in an active position for removing excess liquid from that portion of the ITM when the ITM portion traverses a fixed surplus removal position) and associated with a coating thickness adjustment assembly; The blade exchange mechanism may include a blade exchange mechanism configured to perform a blade exchange operation for exchanging one blade with another blade, and a blade exchange controller for controlling the blade exchange mechanism according to a timing scheme. The timing scheme may mean that the blade exchange controller may control blade exchange so that the blade exchange operation occurs exactly once during each rotation of the ITM.</p><p>In embodiments of the printing system, the blade change controller controls the blade change mechanism to perform a blade change operation only when a preselected one of the first plurality of predetermined portions of the ITM traverses the surplus removal position. It's fine. In some embodiments, the blade exchange controller may additionally or alternatively control the blade exchange mechanism to avoid performing blade exchange operations while the ink image is being transferred to the substrate sheet at the impression station. . In some embodiments, the blade exchange controller may additionally or alternatively control the blade exchange mechanism according to a timing scheme.</p><p>In some embodiments, the printing system may further include a plurality of input devices configured to communicate with the blade exchange controller. The blade exchange controller may control the blade exchange mechanism according to ITM panel position information communicated from the input device.</p><p>As discussed above with respect to particular embodiments, the ITM may include a first and a second plurality of predetermined portions. The second plurality of predetermined portions may include portions of the ITM that include ink image areas. The second plurality of predetermined portions may include portions of the ITM that include seams. In some embodiments, the first and second pluralities are mutually exclusive, and in some embodiments, the first and second pluralities together comprise all portions of the ITM.</p><p>In some embodiments, the coating thickness adjustment assembly may include a blade holder, which may be rotatable and may be a cylinder or a polygonal cylinder, extending radially from the blade holder. It may have blades arranged on it. The blade exchange mechanism according to the embodiment may include, for example, a DC motor or an AC motor. In some embodiments, the blade changing operation comprises rotating the coating thickness adjustment assembly.</p><p>In embodiments, the coating thickness adjustment assembly and blade exchange mechanism are configured such that at a first time before the blade exchange operation, only the first blade is in the active position, and at a second time during the blade exchange operation, the first blade is in the active position. The first blade and the second blade may both be configured to be in the active position, and at a third time after the blade exchange operation, only the second blade is in the active position.</p><p>In some embodiments, the blade exchange controller may control blade exchange to perform exactly one blade exchange operation during each rotation of the ITM. In some embodiments, the blade replacement controller may include a non-transitory computer readable medium containing program instructions, and execution of the program instructions by one or more processors of the computer system causes the blade replacement mechanism to A blade changing operation is performed only when one of the plurality of predetermined portions of the first plurality of ITMs crosses the surplus removal position, and a blade exchange operation is performed only when one of the second plurality of predetermined portions of the second plurality of predetermined portions of the ITM crosses the surplus removal position. The one or more processors may be caused to perform at least one of causing avoidance of performing an exchange operation.</p><p>In embodiments, a printing system in which an ink image is formed on the surface of a rotating intermediate transfer member (ITM) by droplet deposition, transported toward an impression station, and transferred to a substrate, the printing system comprising a blade changing mechanism and a blade changing mechanism. A method of operating a printing system that includes a controller includes applying excess processing fluid to a portion of the surface of a rotating ITM downstream of an impression station and applying excess processing fluid to a portion of the ITM that has excess processing fluid at multiple locations in the active position. It may include conveying through a surplus removal position where surplus liquid is removed by the presence of one of the blades and performing a blade change operation according to a control function. The control function is configured to ensure that an exchange of the blade in the active position with a different blade occurs only when the portion of the ITM being conveyed through the surplus removal position is one of a plurality of predetermined portions. This may be done by a blade changing controller that controls the operation of the blade changing mechanism. In some embodiments of the method, the printing system further comprises a plurality of input devices, and in some embodiments, performing a blade changing operation according to the control function receives location information and ITM from the one or more input devices. receiving at least one of rotational speed information; and initiating a blade changing operation by the blade changing mechanism based on the determination.</p><p>In some embodiments of the method, performing a blade replacement operation according to a control function may comprise determining whether a portion of the ITM satisfies a control function rule for performing the blade replacement operation, and determining It may also include starting a blade exchange operation by the blade exchange mechanism based on the blade exchange mechanism. In some embodiments, performing a blade replacement operation according to the control function may further comprise retrieving the control function rules from computer storage.</p><p>According to embodiments of the method, the control function rules may be included in program instructions executed by one or more processors of the blade replacement controller.</p><p>According to some embodiments, the blade exchange controller is configured to perform blade exchange operations only when the portion of the ITM being conveyed through the surplus removal location is a preselected one of a plurality of predetermined portions. A blade changing mechanism may be controlled. According to some embodiments, the blade change controller may further control the blade change mechanism to avoid performing blade change operations while the ink image is being transferred to the substrate sheet at the impression station. In some embodiments of the method, the blade exchange controller may control the blade exchange mechanism according to a timing scheme.</p><p>According to embodiments of the method, the printing system may include a coating thickness adjustment assembly comprising a blade holder (which may include a cylinder or a polygonal cylinder and may be rotatable), each of the plurality of blades having a blade holder. Extending radially from the holder, the blade changing mechanism may include a motor, and the blade changing operation may include rotating the coating thickness adjustment assembly.</p><p>In embodiments of the method, the coating thickness adjustment assembly and the blade exchange mechanism are arranged such that at a first time before the blade exchange operation, only the first blade is in the active position, and then at a second time during the blade exchange operation. At a time, both the first blade and the second blade are in the active position, and then at a third time after the blade exchange operation, only the second blade is in the active position. In some embodiments, the blade change controller may control the blade change operation to implement a rule that the blade change operation occurs exactly once during each rotation of the ITM.</p><p>In some embodiments of the method, the ITM may comprise a first and a second plurality of predetermined portions, the first and second plurality being mutually exclusive and taken together all portions of the ITM. Equipped with In these embodiments, the blade replacement controller may include a non-transitory computer-readable medium containing program instructions, and execution of the program instructions by one or more processors of the computer system causes the blade replacement mechanism to causing the blade changing mechanism to perform a blade changing operation only when one of the plurality of predetermined portions of the second plurality of predetermined portions of the ITM traverses the surplus removal location; causing one or more processors to perform at least one of causing a blade swap operation to be performed at a time;</p><p>In embodiments, a printing system includes an intermediate transfer member (ITM) comprising an endless flexible belt and an image configured to form an ink image by droplet deposition on a surface of the ITM as it moves through an imaging station. a forming station, an impression station where the ink image is transferred from the ITM surface to the substrate, a conveyor for driving rotation of the ITM to convey the ink image toward the impression station, and an image forming station downstream of the impression station. a treatment station configured to coat the ITM surface with a layer of treatment fluid; the treatment station may include an applicator for applying the treatment fluid to the surface of the ITM; and a blade. a coating thickness adjustment assembly comprising: a blade positioned such that the tip of the blade removes excess treatment agent from a surface of a portion of the ITM that traverses the treatment station to leave only the desired layer of treatment agent; Detecting non-uniform stretching of the ITM associated with traversal of the processing station by a portion of the ITM with a coating thickness adjustment assembly and modulating the timing of droplet deposition to compensate for the non-uniform stretching. and a controller configured to respond by. In some embodiments, non-uniform stretching is caused by interaction of the blade with the surface of the ITM.</p><p>an intermediate transfer member (ITM) comprising an endless flexible belt; an imaging station configured to form an ink image by droplet deposition on a surface of the ITM as it moves through the imaging station; an impression station for transferring the ink image from the surface to the substrate; a conveyor for driving rotation of the ITM to convey the ink image toward the impression station; and an ITM located downstream of the impression station and upstream of the imaging station. a treatment station configured to coat the surface with a layer of treatment fluid; the treatment station may include an applicator for applying the treatment fluid to the surface of the ITM; and a coating thickness adjustment assembly comprising a blade. Coating thickness adjustment in which the blade is positioned such that the tip of the blade interacts with the surface of the ITM to remove excess treatment agent from the surface of the ITM to leave only the desired layer of treatment agent. assembly and the droplet to detect the non-uniform stretching of the ITM caused by the interaction of the blade with the surface of the ITM, and to compensate for the non-uniform stretching of the ITM caused by the interaction of the blade with the surface of the ITM. and a controller configured to respond by modulating the timing of the deposition.</p><p>In any of the above printing systems, the controller is further configured to report detection of non-uniform stretch to an operator or to a log file. The coating thickness adjustment assembly may further include at least one additional blade, and at least part of the time, each one of the blades is physically connected to the surface of the ITM to remove excess treatment agent from the surface of the ITM. It may be configured to be in an active position for interaction.</p><p>In embodiments, a printing system includes an intermediate transfer member (ITM) comprising an endless flexible belt and an image configured to form an ink image by droplet deposition on a surface of the ITM as it moves through an imaging station. a forming station, an impression station where the ink image is transferred from the ITM surface to the substrate, a conveyor for driving rotation of the ITM to convey the ink image toward the impression station, and an image forming station downstream of the impression station. a treatment station configured to coat an ITM surface with a layer of treatment fluid, the treatment station configured to coat the ITM surface with a layer of treatment fluid, the treatment station comprising: an applicator for applying the treatment fluid to the ITM; and a coating thickness adjustment comprising a plurality of blades. an assembly, wherein each one of the blades is in an active position at least part of the time, and a coating configured such that traversing the ITM across the blade in the active position leaves only a layer of a desired treatment agent on a surface of the ITM; a thickness adjustment assembly; and a blade exchange mechanism associated with the coating thickness adjustment assembly and configured to perform a blade exchange operation for exchanging a blade in an active position with another blade, the blade exchange mechanism comprising: , a processing station comprising: a blade changing mechanism that causes a localized stretch of the ITM in the vicinity of a portion of the ITM passing the blade in an active position; and a processing station that detects the localized stretch of the ITM and causes and a controller configured to respond by modulating the timing of droplet deposition to compensate for physical stretching. In some embodiments, local stretching of the ITM may propagate to other portions of the ITM and may not appear near the portion of the ITM that passes the blade in the active position.</p><p>In the printing system described above, modulation may be delayed by the travel time of the non-uniformly stretched portion of the ITM between the processing station and the imaging station.</p><p>In embodiments, a printing system includes a blade in which an ink image is formed on the surface of a rotating intermediate transfer member (ITM) by droplet deposition, transported toward an impression station, and transferred to a substrate. A method of operating a printing system that includes a conditioning assembly includes applying excess processing fluid to a portion of the surface of a rotating ITM downstream of an impression station using a coating applicator; transporting the part through a surplus removal location where excess liquid is removed by interaction of the blade with the ITM due to the presence of the blade and in response to detecting non-uniform stretching of the ITM; and modulating the timing of droplet deposition to compensate for. In some embodiments, non-uniform stretching is caused by interaction of the blade with the surface of the ITM.</p><p>In embodiments, a printing system includes a blade in which an ink image is formed on the surface of a rotating intermediate transfer member (ITM) by droplet deposition, transported toward an impression station, and transferred to a substrate. A method of operating a printing system that includes a conditioning assembly includes applying excess processing fluid to a portion of the surface of a rotating ITM downstream of an impression station using a coating applicator; The presence of the blade allows the transport of the part through a surplus removal position where excess liquid is removed by the interaction of the blade with the ITM and the non-uniformity of the ITM caused by the interaction of the blade with the surface of the ITM. and, in response to detecting the stretching, modulating the timing of droplet deposition to compensate for non-uniform stretching of the ITM caused by interaction of the blade with a surface of the ITM.</p><p>In some embodiments, the method further comprises adjusting the physical position of the blade in response to detecting repeated non-uniform stretching of the ITM. In some embodiments, detection of non-uniform stretching of the ITM is performed by a controller of the printing system. The controller may further be configured to report detection of non-uniform stretching to an operator or to a log file.</p><p>In embodiments, a method of operating a printing system, the printing system comprising a rotating intermediate transfer member (ITM) on a surface of which an ink image is formed by droplet deposition at an imaging station, the printing system further comprising: an imaging station; Upstream of the station, the processing station includes a coating applicator for applying processing fluid to the ITM, a coating thickness adjustment assembly having a plurality of blades, and a coating thickness adjustment assembly for removing excess processing fluid from the surface of the ITM. and a blade exchange mechanism for performing a blade exchange operation to change which blades interact with the ITM. , detecting a local stretch of a portion of the ITM that intersects a processing station or is in the vicinity of a portion of the ITM that passes through the processing station, the local stretch being at least partially caused by a blade change operation. and responding to the detection of the local stretching of the ITM by modulating the timing of droplet deposition to compensate for the local stretching of the ITM. In some embodiments, modulating may be delayed by the travel time of the non-uniformly stretched portion of the ITM between the processing station and the imaging station.</p><p>According to embodiments, a printing system in which an ink image is formed on the surface of a rotating intermediate transfer member (ITM) by droplet deposition, transported toward an impression station, and transferred to a substrate, the coating thickness comprising a blade. A method of operating a printing system that includes a conditioning assembly is to apply excess processing fluid to a portion of the surface of a rotating ITM downstream of an impression station using a coating applicator and to remove an ITM that has excess processing fluid. of the ITM, associated with conveying a portion of the ITM through a surplus removal location where, due to the presence of the blade, excess liquid is removed by interaction of the blade with the ITM, and traversing the surplus removal location by said portion of the ITM. and adjusting the position of the blade in response to the detection of non-uniform stretching.</p><p>In some embodiments, a printing system includes an intermediate transfer member (ITM) that includes a flexible endless belt and is configured to form an ink image by droplet deposition on a surface of the ITM as it moves through an imaging station. an impression station where the ink image is transferred from the ITM surface to the substrate; a conveyor for driving rotation of the ITM to convey the ink image toward the impression station; and an impression station downstream of the impression station. and a processing station configured to coat the ITM surface with a layer of processing liquid, the processing station being disposed upstream of the imaging station, the processing station comprising an applicator for applying the processing liquid to the surface of the ITM and a blade. a coating thickness adjustment assembly, the blade being positioned such that the tip of the blade removes excess treatment agent from a surface of a portion of the ITM that traverses the treatment station, leaving only a desired layer of treatment agent; The coating thickness adjustment assembly and the operator detects non-uniform stretching of the ITM associated with traversal of the processing station by a portion of the ITM and adjusts the blade position or recommends a blade position adjustment. or a controller configured to respond by reporting to a log file.</p><p>The invention will now be described in detail by way of example with reference to the accompanying drawings, in which the dimensions of the components and features illustrated therein have been chosen for convenience and clarity of presentation. Yes, it is not necessarily scaled to a fixed ratio.</p>

<figref num="1">1 is an elevational view of a printing system according to an embodiment.</figref><figref num="2A">FIG. 1 is an elevational view of components of a printing system according to an embodiment.</figref><figref num="2B">FIG. 1 is an elevational view of components of a printing system according to an embodiment.</figref><figref num="2C"><u style="Single">FIG. 1 is an elevational view of components of a printing system according to an embodiment.</u></figref><figref num="3">1 is an elevational view of a doctor blade with solute accumulation, according to an embodiment; FIG.</figref><figref num="4">FIG. 5 is an alternative elevational view of components of a coating thickness adjustment assembly according to an embodiment.</figref><figref num="5A">FIG. 5 is an alternative elevational view of components of a coating thickness adjustment assembly according to an embodiment.</figref><figref num="5B">FIG. 5 is an alternative elevational view of components of a coating thickness adjustment assembly according to an embodiment.</figref><figref num="6">FIG. 1 is an elevational view of components of a printing system according to an embodiment.</figref><figref num="7">5 includes views of the components of the coating thickness adjustment assembly of FIG. 4 at three different times, according to an embodiment; FIG.</figref><figref num="8">1 includes an alternative top schematic view of an intermediate transfer member (ITM) according to an embodiment; FIG.</figref><figref num="9">1 includes an alternative top schematic view of an intermediate transfer member (ITM) according to an embodiment; FIG.</figref><figref num="10">1 is an elevational view of a printing system including a locator and a stationary locator, according to an embodiment. FIG.</figref><figref num="11">1 is an elevational view of a printing system according to an embodiment.</figref><figref num="12">FIG. 2 is a schematic plan view of an ITM panel and seam according to an embodiment.</figref><figref num="13A">1 includes an alternative top schematic view of an intermediate transfer member (ITM) according to an embodiment; FIG.</figref><figref num="13B">1 includes an alternative top schematic view of an intermediate transfer member (ITM) according to an embodiment; FIG.</figref><figref num="14">1 includes an alternative top schematic view of an intermediate transfer member (ITM) according to an embodiment; FIG.</figref><figref num="15">1 includes an alternative top schematic view of an intermediate transfer member (ITM) according to an embodiment; FIG.</figref><figref num="16">1 is a flowchart of a method of operating a printing system including a blade exchange mechanism and a blade exchange controller, according to an embodiment.</figref><figref num="17">2 is a flowchart of a method of operating a printing system including a blade exchange mechanism and a blade exchange controller, according to an alternative embodiment.</figref><figref num="18">3 is a flowchart of a method for performing a blade replacement operation according to a control function, according to an embodiment.</figref><figref num="19">5 is a flowchart of another method for performing a blade change operation according to a control function, according to an embodiment.</figref><figref num="20">2 is a flowchart of another method of operating a printing system including a blade exchange mechanism and a blade exchange controller, according to an embodiment.</figref><figref num="21">5 is a flowchart of another method for performing a blade change operation according to a control function, according to an embodiment.</figref><figref num="22A">FIG. 2 is a schematic diagram of physical forces that affect the interaction of a doctor blade and an ITM, according to an embodiment.</figref><figref num="22B">FIG. 2 is a schematic diagram of physical forces that affect the interaction of a doctor blade and an ITM, according to an embodiment.</figref><figref num="22C">FIG. 2 is a schematic diagram of physical forces that affect the interaction of a doctor blade and an ITM, according to an embodiment.</figref><figref num="22D">FIG. 3 is a schematic illustration of a portion of an ITM with non-uniform stretching caused by the interaction of a blade with a surface of the ITM, according to an embodiment;</figref><figref num="23">1 is an elevational view of a printing system according to an embodiment.</figref><figref num="24">1 is a flowchart of a method of operating a printing system that includes a coating thickness adjustment assembly that includes a treatment fluid applicator and a blade, according to an embodiment.</figref><figref num="25">2 is a flowchart of another method of operating a printing system including a coating thickness adjustment assembly including a treatment fluid applicator and a blade, according to an embodiment.</figref><figref num="26">1 is a flowchart of a method of operating a printing system that includes a treatment fluid applicator, a coating thickness adjustment assembly with a plurality of blades, and a blade exchange mechanism, according to an embodiment.</figref>

The invention will be described herein, by way of example only, with reference to the accompanying drawings, in which: FIG. When reference is now made to the drawings in specific detail, what is shown is for the purpose of illustrating, by way of example only, a preferred embodiment of the invention and is intended to illustrate the principles and conceptual aspects of the invention. Emphasis is presented in order to provide what is believed to be the most useful and easily understood description of the aspects. In this regard, no attempt has been made to present structural details of the invention in more detail than is necessary for a basic understanding of the invention, and this description does not explain how the several forms of the invention It is taken together with the drawings which will make it clear to those skilled in the art how it can be implemented in practice. Like reference numbers are generally used to represent like elements throughout the drawings.

For convenience, various terms are presented here with respect to the description herein. To the extent that definitions are provided explicitly or implicitly herein or elsewhere in this application, such definitions are to be understood as consistent with the usage of the defined term by one or more persons skilled in the art. Ru. Additionally, such definitions are to be interpreted in the broadest possible sense consistent with such usage.

"Control Function" as used herein refers to retrieving data from computer storage, retrieving system operating rules (also referred to as "rules" or "control function rules") from computer storage, or from an input device. receiving data, executing program instructions, making calculations, decisions, and judgments by executing program instructions; Refers to functions performed by a controller, including, but not limited to, transmitting signals.

"Controller," as used herein, refers to one or more of the operations of a printing system or one or more printing system components according to program instructions that may include rules, machine learning rules, algorithms, and/or heuristics. It is intended to represent any processor configured to control multiple aspects, or a computer comprising one or more processors, the method of programming thereof being irrelevant to the present invention. The controller may be a stand-alone controller with a single function as described above, or may have multiple control functions according to embodiments herein and/or not related to or disclosed herein. One or more control functions that are not specified may be combined. For example, a single controller may be provided to control all aspects of the operation of the printing system, and the control functions described herein are one aspect of the control functions of such a controller. Similarly, the functionality disclosed herein with respect to a controller may be divided or distributed across multiple computers or processors, in which case any such multiple computers or processors may be considered a single controller for purposes of this definition. computer or processor. Although some components associated with computer networks, such as communication devices and data storage devices, have been omitted herein for clarity, those skilled in the art will appreciate that a controller as used herein It will be appreciated that any network gear or auxiliary equipment necessary to perform the functions described herein may be included.

In various embodiments, an ink image is first deposited on the surface of an intermediate transfer member (ITM) and transferred from the surface of the intermediate transfer member to a substrate (ie, a sheet or web substrate). In the context of this disclosure, "intermediate transfer member," "image transfer member," and "ITM" are synonymous and may be used interchangeably. The location where ink is deposited on the ITM is referred to as the "imaging station." In many embodiments, the ITM comprises a "belt" or "endless belt" or "blanket," and these terms are used interchangeably with ITM. The area or area of the printing press where the ink image is transferred to the substrate is the "impression station." As will be appreciated, for some printing systems there may be multiple impression stations.

For endless intermediate transfer members, the "length" of the ITM is defined as its perimeter. An endless intermediate transfer member may be formed by joining the ends of the belt with a seam. The seam may be created by any method of joining the ends of the belt depending on the material used in the belt, and may include, for example, stitching, closing zippers, using hook-and-loop fasteners, heat welding and ultrasonic welding; For example, the ends may be joined using rivets, screws, bolts, snaps, clips, fasteners comprising metal, plastic, or composite materials, or adhesives. These examples are not intended to be exhaustive, but to illustrate the variety of joining methods available to those skilled in the art.

Referring now to the drawings, FIG. 1 is a schematic diagram of a printing system 100 according to some embodiments of the invention. The printing system 100 of FIG. 1 includes an intermediate transfer member (ITM) 210 comprising a flexible endless belt mounted on a plurality of guide rollers 232, 240, 250, 253, 242. In other examples (not shown), ITM 210 is a drum or a belt wrapped around a drum. This figure illustrates certain configuration aspects relevant to the description of the invention, and the configuration shown is not limited to the number and arrangement of rollers presented, but also to their shape and related dimensions. However, all of them are shown here for convenience to clearly illustrate the system components.

In the example of FIG. 1, ITM 210 rotates in a clockwise direction with respect to this diagram. The direction of belt movement defines the upstream and downstream directions. Because rollers 242, 240 are located upstream and downstream of imaging station 212, respectively, roller 242 may be referred to as an "upstream roller" and roller 240 may be referred to as a "downstream roller." The printing system 100 further includes (a) each print bar comprising inkjet print head(s) 223 (each designated one of C, M, Y, and K), as shown in FIG. ) Imaging station 212 with print bars 222A-222D. The imaging stage 212 is configured to form an ink image on the surface of the ITM 210 (e.g., with a droplet deposited thereon), (b) a drying station 214 for drying the ink image, and (c) ) an impression station 216 where the ink image is transferred from the surface of the ITM 210 to a sheet 231 or web substrate (only the sheet substrate is shown in FIG. 1).

In the specific non-limiting example of FIG. 1, impression station 216 includes an impression cylinder 220 and a blanket/pressure cylinder 218 carrying a compressible blanket 219.

(d) upstream of the impression station where residual material (e.g. the processing film and/or ink image or portion thereof, or other residual material) is removed from the surface of the ITM210 (just one of the cleaning methods that may be used within the system); A cleaning station 258 (which may include a cleaning brush as shown in FIG. 1, for example).

(e) a treatment station 260 upstream of the impression station and cleaning station where a treatment fluid (eg, treatment aqueous solution) is applied to the ITM surface; By way of example, the processing solution may comprise a dilute solution of a charged polymer and may be a suitable processing solution. Backing roller 1141 is located on the opposite side of ITM 210 from processing station 260.

Those skilled in the art will understand that not all components shown in FIG. 1 are required. The cooling and cleaning stations may also be combined into a single station and may also perform a cooling function to cool the ITM 210 before it advances to the imaging station 212.

Example of doctor blade design and function

The following paragraphs provide exemplary, non-limiting examples of doctor blade design and function according to various embodiments of the present invention.

FIG. 2A schematically depicts in cross-section one non-limiting example of a processing station 260, which in this example is a processing solution fountain configured to apply processing solution 2030 to the surface of ITM 210. 1128, a doctor blade 2014 arranged to remove excess processing solution 2031 from the ITM, and a tank 2016 for excess processing solution 2031. In the figure, the indicated portion of ITM 210 is shown running from right to left (i.e. clockwise) as seen by arrow 2012 over a doctor blade generally designated 2014 and properly installed within tank 2016. (as part of the lower stroke ). In the example of FIG. 2A, the doctor blade 2014 is formed of a rigid bar with a smooth, regular cylindrical surface that extends across the width of the ITM 210.

Prior to passing over the doctor blade 2014, the backside (or lower stroke) of the ITM 210 is coated with excess treatment agent (eg, solution) 2030. Neither the manner in which the excess treatment agent (e.g., solution) is applied to the ITM210 or the type of applicator used for coating is of fundamental importance to the invention; the ITM210 may be, for example, simply It may be immersed, passed over a fountain 1128 of treatment agent (eg, treatment solution) 2030 as shown in FIG. 2A, or sprayed by an upwardly directed jet (not shown). Those skilled in the art will recognize that the processing solution may be applied to the ITM 210 by any suitable applicator, such as those described above, or by other means not as disclosed herein.

As shown, as the ITM 210 approaches the doctor blade 2014, the ITM 210 has a liquid coating 2030 that is above or significantly above the desired thickness. The function of the doctor blade 2014 is to remove excess liquid 2031 from the ITM 210 and ensure that the remaining liquid is evenly and uniformly spread over the entire surface of the ITM 210. In a non-limiting example, doctor blade 2014 may be biased toward ITM 210 while ITM 210 is maintained in tension. For example, doctor blade 2014 may be biased toward ITM 210 to force ITM 210 against backing roller 1141. In other examples, backing roller 1141 may be biased downward to provide additional force as ITM 210 traverses doctor blade 2014. Although the backing roller 1141 is shown as a cylindrical roller, it may actually have a flat, oval, or oblong surface facing the ITM 210, the principle being that on the opposite side of the ITM 210 from the doctor blade 2014, 2014 is the presence of an object with an opposing force or presence that increases the effectiveness of the redundancy removal function. In some embodiments, the backing roller 1141 is inserted into the backing roller 1141 such that the tip of the doctor blade 2014 "sinks" or deforms the surface of the backing roller 1141 into the flexible ITM 210, as schematically shown in FIG. 2C. Roller 1141 may have a soft or compressible surface. The compressibility of the surface of the backing roller 1141 and/or the extent to which the doctor blade 2014 causes indentation or deformation of the surface of the backing roller 1141 adjusts the thickness of the processing solution 2030 at the surface of the ITM 210 in some embodiments. Used as a factor. The embodiment shown in FIG. 2C and the feature of recessing or deformation of backing roller 1141 may be used in combination with any of the other embodiments herein, even if that feature is not explicitly mentioned.

Those skilled in the art will recognize that processing solutions may be applied to ITM 210 by other means, and excess liquid 2031 may be removed by other means.

In another example of a processing station schematically shown in FIG. 2B, the doctor blade 2014 may include a doctor bar 2020 and a doctor rod 2022. The doctor bar 2020 preferably has a groove 24 or equivalently a notch or opening into which the doctor rod 2022 is introduced, and may be of more robust construction than the doctor rod 2022. In some embodiments, doctor bar 2020 is rigid and extends across the width of ITM 210. On the back-facing upper surface of ITM 210, bar 2020 is formed with a channel or groove 24 inside which rod 2022 is supported. The functionality and operation of processing station 260 in FIG. 2B is the same as in FIG. 2A. Doctor rod 2022 may be retained within groove 24 by any means, such as by welding, adhesive, friction, or mechanical fasteners such as screws or bolts.

In embodiments, the tip of the doctor blade 2014 comprises a smooth rod 2022 with a uniform radius across the width of the ITM 210, the smoothness of which ensures laminar flow of liquid in the gap between the smooth rod 2022 and the back side of the ITM 210. . The properties of this flow may be similar to those of liquid lubricants in hydrodynamic bearings, and the film of liquid 2030 that remains on the surface of ITM210 is reduced by the force that urges ITM210 against doctor blade 2014 and the rod. Reduce to a thickness dependent on the radius of curvature of 2022. Since both radius and force are constant across the width of the web, the resulting membrane is uniform and its thickness can be set by appropriate selection of applied force and rod diameter.

A tank 2016 containing excess treatment agent (e.g., solution) may be a primary storage tank from which liquid is drawn to apply treatment agent 2030 to the back side of the web with excess treatment agent 2030 (e.g., solution); Alternatively, tank 2016 may be a separate tank that is drained to a main storage tank (not shown) and/or emptied to a suitable exhaust system (not shown).

Rod 2022 is preferably made of a hard material, such as hardened steel or fused silica, to resist abrasion. There may be small particles of sand or dust in the liquid that can damage the rounded edges over which the liquid flows. In embodiments, the material must be capable of being formed into a smooth rod of uniform diameter or thickness and a surface roughness bordering the ITM of less than 10 microns, especially less than 0.5 microns. The cross-section of the doctor rod 2022 may have a circular cross-section (in a plane perpendicular to the floor surface), or the cross-section may have any rounded shape, such as an ellipse or an oblong, or It may have a rounded tip 1125 as shown in FIG. Doctor rod 2022 may have a radius or thickness of 6 mm, or even 0.5 mm, and is relatively fragile and may require mechanical support, for example by doctor bar 2020.

In some cases, when using such a doctor blade in connection with the application of certain formulations (e.g. solutions), solute deposits 34 may accumulate downstream of the doctor blade 2014, as shown schematically in Figure 3. be done. Although FIG. 3 shows the example of the single-component doctor blade 2014 described with reference to FIG. 2020 and doctor rod 2022. The formation of such deposits and their composition, if allowed to grow excessively, will eventually interfere with the layer of treatment agent (eg, solution) applied to the ITM 210.

Replacing or replacing the doctor blade

Embodiments of the present invention relate to apparatus and methods for replacing or replacing a doctor blade when it becomes dirty. Figure 4 shows an example of how the doctor blade can be easily replaced, preferably without the need to interrupt the web coating process or printing system that requires conditioning agent to be applied to the ITM. .

In the non-limiting example of FIG. 4, twelve doctor blades 1122 are mounted evenly in recesses 1123 along the circumference of a cylindrical turret 1120 that is rotatable about an axis 1127. Cylindrical turret 1120 acts as a blade holder for multiple blades. The radially extending doctor blade 1122 behaves similarly to the doctor rod 2022 of FIG. 2B, and the turret 1120 serves the same purpose and function as a rod holder as the doctor bar 2020 of FIG. 2B. Rather than using a circular, oval, or oval cross-section rod, the doctor blade 1122 is configured as an elongated strip with a smooth, rounded abrasive edge. Strips with rounded edges of uniform radius of curvature can be produced, for example, by flattening a rod of circular cross section. Doctor blade 1222 may preferably be made of stainless steel, although other abrasion resistant hard materials may be used.

It will be clear to those skilled in the art that the blade holder (eg, turret) may have a different configuration than shown here without changing its function. For example, as shown in FIGS. 5A and 5B, the cylindrical rotatable turret 1120A may have a polygonal cross-section rather than a circular cross-section. In FIG. 5A, the doctor blade 1122 extends radially from the side of the polygonal cylinder 1120a, whereas in FIG. 5B, the doctor blade 1122 extends radially from the corner of the polygonal cylinder 1120b. It should be understood that the number of blades or polygonal sides, as well as corner radii and other geometrical aspects, may be selected by one of ordinary skill in the art when designing such a system. In various embodiments, the blade holder may include a solid cylinder, or may include a skeletal structure, so long as it is designed to perform equivalent functions, such as gripping and being rotatable for a plurality of doctor blades 1122. good. For clarity, the description herein refers only to turret 1120, but it should be understood that the following includes variations such as 1120a or 1120b. In other embodiments, blade replacement may be accomplished by other configurations that do not require the blade holder to be rotatable.

The manner in which turret 1120 and doctor blade 1122 interact with ITM 210 is illustrated in FIG. 6, which shows an example of processing station 260 in more detail.

In the example of FIG. 6, one of the twelve doctor blades 1122 traverses a position of one of the twelve doctor blades 1122 while the ITM 210 moves in the printing direction indicated by the arrow 2012 to remove excess liquid, such as a processing agent, for example. (referred to in this disclosure as the "active position") facing the ITM 210. The coating process as described above in the description with reference to FIG. 2A also relates to the embodiment shown here. In Figure 6, one of the blades 1122_ACTIVEis the "active blade" for the removal of excess treatment agent 2031 because it is closest to ITM 210 among the blades 1122, and active blade 1122_ACTIVEThe tip 1125 faces the ITM 210. The other doctor blades 1122 shown in the figure are referred to as "inactive." Active Doctor Blade 1122_ACTIVEThe location facing ITM 210 for removing surplus processing agent 2031 is hereinafter referred to as "surplus removal position."

As the ITM 210 rotates and a portion of the ITM 210 traverses this excess removal location in the indicated direction, this causes the removal of excess treatment agent 2030 from the surface of the portion of the ITM 210 with only one blade 1122_ACTIVEIt is. 6 schematically depicts the position of the illustrated elements at certain times (not shown), the doctor blade 1122 shown as inactive in FIG. 6 may be active and at other times (not shown) Active Doctor Blade 1122 shown in_ACTIVEmay be inactive.

Active Doctor Blade 1122_ACTIVE(or its rounded tip 1125) towards the blade holder (turret 1120 in this view) and other doctor blades 1122 not in the active position, and backing roller 1141 (or its rounded tip 1125). The device for supplying pneumatic pressure) collectively comprises a coating thickness adjustment assembly, i.e., the thickness of the treatment agent 2030 remaining on the portion of the ITM 210 that traverses the surplus removal location is adjusted, in particular, by the active doctor blade 112._ACTIVEmay be adjusted according to the magnitude of the force F1 that propels the tip 1125 of the ITM 210 toward the opposing portion of the ITM 210 or vice versa. As shown earlier in Figure 2C, the force F1 causes the active doctor blade 1122 to_ACTIVEThe force F1 contributes to adjusting the thickness of the treatment agent 2030 as the ITM 210 and the thin layer of treatment agent 2030 may sink into or deform the backing roller 1141. Figure 6 shows active doctor blade 1122 from the direction of backing roller 1141 through ITM210_ACTIVEIn some embodiments, a similar force is applied in the opposite direction (with the backing roller 1141 on the opposite side of the ITM 210), i.e., on the active doctor blade 1122._ACTIVEIt is added from ITM210 toward ITM210. Regardless of which direction the force is applied, the principle is that when a force is applied perpendicular to the ITM 210, removal of excess liquid can be enhanced and regulated.

In the non-limiting example of FIG. 6, there is only one doctor blade 1122, specifically an active doctor blade 1122._ACTIVEinteracts with ITM 210 at any given time. However, if the blade 1122 becomes contaminated, for example by dried solution 34 (not shown in FIG. 6 but shown in FIG. 3), it may be desirable to bring the next adjacent doctor blade 1122 into the active position as described above. In this illustrated example, rotation of the turret 1120 is suitable to accomplish this blade change. A blade exchange mechanism, e.g., a motor 1140 that rotates the turret 1120 about an axis, is shown to enable a blade exchange operation in which an active blade in the active position is exchanged with a different blade that was not previously in the active position. It can be provided as follows.

In some embodiments, the dirty blade 1122 is removed by a continuous blade change operation as the turret 1120 rotates, i.e., before being returned to the active position at a later stage in the turret rotation cycle, before returning the blade to the active position again. It passes through a cleaning device, for example a stationary or rotating brush 1130, as shown schematically in FIG. 6, which removes any deposits and cleans the blade.

In embodiments, blade replacement operations may be initiated upon request by an operator or may occur at predetermined intervals. In other embodiments, blade exchange operations may be controlled by a blade exchange controller 1150 that applies rules regarding when blade exchange operations do and do not occur. In some embodiments, the blade replacement controller 1150 comprises a non-transitory computer-readable medium containing program instructions, and execution of the program instructions by one or more processors of the computer system causes the blade replacement controller 1150 to Allowing the mechanism to control when to perform, enable, or effect a blade change operation, or avoid or prevent a blade change operation. Enabling or avoiding a blade change operation may be based on timing and what portions of the ITM 210 may or may not be able to traverse the surplus removal position at the time of the blade change operation.

The number of doctor blades 1122 installed on turret 1120 need not be twelve as shown; any number of blades 1122 can be installed on turret 1120. In some embodiments, during swapping, ie, during a blade change operation, there is a time when two doctor blades 1122 function simultaneously and interact with the ITM 210 (are "active") and both occupy the surplus removal position. It is desirable that there be a sufficient number of This provides a nearly continuous transition from the active state of one blade to the active state of another blade, thereby eliminating the need for any interruption in the operation of the coating thickness adjustment assembly and interrupting the printing system. This allows the doctor blade 1122 to be replaced without any trouble.

Referring to FIG. 7, components of an embodiment of a printing system 100 are shown at three different times. At time T1, the figure shows a situation similar to that shown in Fig. 6, where 1122₁is displayed as 1122 in Figure 6._ACTIVEThe first doctor blade equal to is the only doctor blade 1122 in the active position. 2nd Doctor Blade 1122₂is in an inactive position opposite excess liquid removal. Turret 1120 in this non-limiting example is configured to rotate counterclockwise as shown by arrow 2103 so that second doctor blade 1122₂is clearly the next doctor blade in the active position after a blade change operation involving counterclockwise rotation of the turret 1120. Time T2 is a time after T1, and the blade replacement operation has started, but has not yet been completed. At this point, the first doctor blade 1122₁has already started moving from the position held at time T1, but has not yet reached the inactive position. 2nd Doctor Blade 1122₂First Doctor Blade 1122 at time T1₁It has started moving by rotation towards the position where it was, but it has not reached there yet. The coating thickness adjustment assembly and blade changing mechanism preferably connect the first and second doctor blades 1122 at time T2.₁and 1122₂are both in their respective active positions, i.e. both blades are configured to interact with the ITM210 and provide continuous excess liquid removal; in this case, excess removal is It is continuously assisted by the pressure or other force applied through or towards the backing roller 1141 and the softness or compressibility of the backing roller 1141. It should be noted that when the two blades 1122 are both in the active position as shown in FIG.₁and 1122₂should be taken to mean the position of the rectangular flat portion substantially parallel to the ITM 210 defined by the respective tips 1125 of the ITM 210 . At time T3, the blade exchange operation is complete and the first doctor blade 1122₁has reached an inactive position and its tip has moved far enough away from ITM 210 that it will not interfere with ITM 210 for removal of excess liquid as it traverses the processing station. 2nd Doctor Blade 1122₂First Doctor Blade 1122 at time T1₁At this point, it is the only doctor blade in the active position because it has moved to the active position where it was.

As will be clear to those skilled in the art, the various examples described and illustrated herein with respect to coating thickness adjustment assemblies and blade change mechanisms are designed to remove excess liquid (e.g., treatment agent) and remove blades in the active position. This is not the only possible design choice for these components, as long as the basic principles of replacement are adhered to.

Referring to Figure 8, the ITM 210 may be defined by a length measured in the printing direction (printing direction is shown as arrow 2012) and a width in the W direction; since this figure is a top view, the printing direction The 2012 and W directions together define a plane. In examples where the ITM210 comprises an endless belt rotating through the printing system, its length is equal to the circumference or the length of the material whose ends are joined, e.g. by a seam, to form the endless belt. be equivalent to. According to some embodiments, the ITM 210 comprises a plurality of ITM panels 700, each having a width approximately the same as the ITM 210, and a panel length LP greater than 0 and less than the length of the ITM. In some embodiments, the ITM panels are physically separated portions of the ITM, such as by marks on the ITM or grooves or other mechanical modifications in the ITM. In other embodiments, the ITM panel is a virtual (meaning not physically separate) portion of the ITM whose dimensions are stored in the computer system.

ITM 210 may include any number of ITM panels, and the number of ITM panels may be selected according to the particular design and size of the printing system. For example, ITM210 has N panels 700₁、700₂、700₃、・・・、700_Nmay be provided. In some embodiments, each of the panels has the same panel length LP, such as the example shown in FIG. 8, and the length of ITM 210 is an integer multiple of LP. Since the example in FIG. 8 comprises N panels of length LP, the total length of the ITM in this example is equal to N×LP. In other embodiments, the panels may have varying lengths. In the example shown in Figure 9, all but one of the panels have length LP, and panel 700₃has length LP+M, where M is any positive number.

The ITM panel 700 includes an ink image area 710, which is an area of the ITM panel where an ink image is regularly formed each time the panel passes the imaging station 212. For example, ITM panel 700₁is the ink image area 710₁Equipped with ITM Panel 700₂is the ink image area 710₂and the same for the N panels and N respective ink image areas.

In some embodiments, ITM panel 700 includes a locator 720 that is used to locate ITM panel 700 relative to other components of printing system 100. Locator 720 comprises one of a marker and an input device. The marker may be an optical marker, a magnetic marker, a mechanical marker, or an electronic marker, such as a radio frequency identification device (RFID). The input device may be a sensor or a detector, such as a detector configured to detect a marker and/or receive data communications from the marker. In some embodiments, each ITM panel comprises a marker as a locator 720, and in these embodiments a fixed locator 810 (see FIG. (described below with reference to) is configured to detect the markers and thereby determine and/or track the position of the markers and the panel at all times as they move through the ITM rotational path. In other embodiments, each ITM panel 700 comprises an input device, such as a sensor or marker detector, as a locator 720, which preferably comprises one or more markers installed somewhere within the printing system. a fixed locator 810 of, thereby determining and/or tracking the position of the input device and the panel at all times as they (locator 720 with input device and respective ITM panel 700) move through the ITM rotational path. configured. Tracking of the ITM panel to a fixed position within the printing system ensures that the ink image is formed on the desired portion of the ITM, e.g. in the ink image area where the ink image was previously formed. It may be useful to control some operational function of the system, such as Tracking of ITM panels and their respective locators relative to a fixed position may be determined by parameters such as, for example, the rotational speed of the ITM or the position of any particular panel or portion or locator of the ITM at any time, and such parameters based on the rotational speed. May be useful for determining location predictions. Tracking may also help avoid forming ink images in undesired parts of the ITM, such as outside the ink image area or on seams. The tracking is used to control the blade changing mechanism to ensure that blade changing operations are not performed when a portion of the ITM containing either the ink image area or the seam traverses the surplus removal position, or the ink image area. or to control the blade change mechanism to ensure that the blade change operation is performed only when a part that does not include a seam crosses the surplus removal position, or only when a particular part crosses the surplus removal position. It may be useful in conjunction with embodiments disclosed herein to control a blade changing mechanism to ensure that a blade changing operation is performed.

FIG. 10 shows an example of a printing system 100 with a locator 720 at an ITM panel 700 and a corresponding fixed locator 810 located somewhere within the printing system 100. The example of locator 720 shown in the figure is locator 720_X、720_Y, and 720_Zand all of them are installed in ITM210. The example of fixed locator 810 shown in the figure is fixed locator 810_A、810_B, and 810_C, each of which, in a non-limiting example, is a rigid frame element 245 of the printing system 100._A、245_B, and 245_Cbe attached by suitable means. Of course, any number of locators 720 may be provided, and any number of fixed locators 810 may be provided. As mentioned above, any of the locators 720 may be markers or input devices, and any of the fixed locators 810 may be markers or input devices, the principle being that the fixed marker The input device is in communication with a moving input device, and the input device is in communication with a marker that moves with rotation of the ITM. Communication between the marker and the input device may be optical, magnetic, electronic, including RFID, and/or mechanical.

Rotation of the ITM panel 700 through the ITM rotation path may include at least two periods in a single printing cycle. During the first time period, ink image area 710 comprises ink images 711 (not shown since each ink image 711 is coextensive with its respective ink image area 710). As shown in FIG. 11, a first period covers a portion of the ITM rotation path that begins at imaging station 212, where an ink image 711 is formed on the ITM panel 700, and ends at impression station 216, where the ink image 711 is transferred to the substrate. Corresponding to the ITM panel 700 traversing. The second period corresponds to the ITM panel traversing the remainder of the ITM rotation path, the portion of the ITM rotation path that begins after impression station 216 and ends before print station 212 where ink image 711 is transferred to the substrate. . During the second period, the ink image area 710 does not include an ink image 711, but the ink image 711 is added to the ink image area 710 each time the ink image area (and the respective ITM panel) passes through the imaging station 212. It is formed regularly, specifically as soon as the ink image area 711 passes through the imaging station 212 again.

Figure 12 shows two adjacent ITM panels 700_N、700₁each subscript indicates that seam 800 is placed between the last (Nth) panel and the first panel in this non-limiting example. show. The configuration of seams 800 and methods for creating or providing them on ITM 210 have been described above.

When a "sensitive" portion of the ITM is traversing the surplus removal location, it is desirable to avoid performing a blade change operation, as described above. The force of the blade changing action places excessive stress on the part of the ITM that passes over the tip of the doctor blade held in the active position, and may reduce the quality of the treatment layer applied to the ITM (e.g. its uniformity, desired thickness). The movement of the blade in and out of the active position should preferably occur when there are no sensitive areas, as this can reduce the susceptibility (e.g. It should be noted that the blade change operation preferably occurs very quickly, for example less than 100 ms, less than 50 ms, or less than 10 ms, as the blade is subjected to a high degree of acceleration. , meaning that the blade is subjected to large forces that can mechanically affect sensitive parts of the ITM with which it physically interacts. An example of a sensitive portion is a portion containing an ink image area. This use also applies not only to the formation of an ink image, since the ink image area is used repeatedly for the formation of an ink image thereon, but also to the substrate at the impression station, where strong mechanical forces may be applied to effect the transfer. transfer of the image is also necessarily involved, so the part containing the ink image area is thinner, more worn, exhibits material fatigue, or is susceptible to the forces dynamically applied to its surface by the blade changing action. It may be less robust in terms of mechanical resistance. In addition, the dynamic stresses of the blade exchange operation can have a detrimental effect on the future usefulness of the ITM portion that passes through the active area during the blade exchange operation, so this section must not be used for repeated ink imaging and impression stations. In the future, it may become mechanically unsuitable for repeated printing operations, including repeated transfer to substrates by impressions. ITMs can become stretched, thinned, frayed, or otherwise damaged by experiencing repeated blade-changing operations, resulting in a less conductive printed surface or a shorter operating life. , requiring replacement sooner than otherwise. It may also be particularly important that the processing agent is as uniform as possible and as close to the desired thickness as possible, especially in the ink image areas, and as mentioned above, the blade changing operation It can locally affect the thickness and uniformity of the treatment agent in the portion of the ITM across the treatment station. Other examples of delicate parts are parts that include seams. Seams subjected to the stress of blade changing operations, whether once or repeatedly, can become weakened, tear, fray, or otherwise fail, rendering them useless for future operations. Therefore, in some embodiments, it is desirable to control the occurrence of blade exchange operations to avoid performing blade exchange operations while such sensitive ITM portions traverse the surplus removal location. In some embodiments, it is desirable to control the occurrence of a blade change operation to ensure that the blade change operation occurs only when a non-sensitive portion of the ITM traverses the surplus removal location. In some embodiments, it is desirable to control the occurrence of a blade change operation to ensure that the blade change operation occurs only when a particular non-sensitive portion of the ITM traverses the surplus removal location. Although delicate parts other than those containing ink image areas or seams may exist in the ITM, for clarity, only these two examples are used herein to illustrate the concept of delicate parts. It will be done. In some embodiments, it is desirable to control the occurrence of blade changes to perform blade change operations based on the timing of ink imaging in the ITM. In some embodiments, it is desirable to control the occurrence of blade changes to perform blade change operations based on the timing of ink image transfer from the ITM to the substrate.

Referring to FIG. 13A, the ITM 210 according to an embodiment includes a plurality of portions 750 that include regions between adjacent ink image regions 710 but do not include any ink image regions 710 or portions thereof, or regions comprising seams 800. Equipped with These portions 750 are other than those described above as sensitive areas, and in some preferred embodiments, a blade change operation is performed only when one of these portions 750 traverses the surplus removal location. be done. In an alternative embodiment, the ink image area 701_Nand seam 800, and/or seam 800 and ink image area 701₁There may be an intervening section between the Both of these depend on the later ink image area 710_Nbetween the traverse of seam 800 and the traverse of seam 800, or between the traverse of seam 800 and the ink image area 701₁Determine whether there is sufficient time between each traverse to allow a blade change operation. In embodiments where a blade change operation is performed only when one of these portions 750 traverses the surplus removal position, a blade change controller, such as the blade change controller 1150 described above, may perform a blade change operation only when one of these portions 750 crosses the surplus removal position. A processor is included for executing program instructions to limit the time period of traversing the redundancy removal location.

In FIG. 13B, the ITM 210 according to an embodiment includes a plurality of portions 760 including an ink image area 710 and a seam 800. These portions 760 include those described above as sensitive areas, and in some preferred embodiments, a blade change operation is not performed when one of these portions 760 traverses the surplus removal position. In an alternative embodiment, the ink image area 701_Nand ink image area 701₁The portion 760 shown in the area between the component), and the rotational speed of ITM210, both of which depend on the subsequent ink image area 710_Nbetween the traverse of seam 800 and the traverse of seam 800, or between the traverse of seam 800 and the ink image area 701₁Determine whether there is sufficient time between each traverse to allow a blade change operation. According to embodiments in which a blade change operation occurs only when these portions 760 traverse the surplus removal position, a blade change controller, such as the blade change controller 1150 described above, may cause the printing system 100 to have one of these portions 760 A processor is included for executing program instructions to avoid performing blade replacement operations during the traversal of the surplus removal location.

FIG. 14 shows an ITM 210 comprising a first plurality of portions 750, as described above with reference to FIG. 12A, and a second plurality of portions 760, as described above with reference to FIG. 12B. As shown, there is no overlap between the two plurality portions 750, 760, and they are mutually exclusive. In addition, ITM 210 is entirely composed of two plurality of parts 750, 760, and there is no ITM part that is neither the first plurality of parts nor the second plurality of parts.

In FIG. 15, ITM 210 includes a preselection portion 770. In some embodiments, the ITM 210 of FIG. 15 is the same as the ITM 210 of FIG.₃has a greater length than the other panels 700, in which case the preselected portion 770 preferably₃ink image area 710₃and edge 715 together with a large panel. Pre-selected portion 770 does not include sensitive portions as referred to herein. In embodiments, the blade change operation preferably occurs when the preselected portion 770 traverses the surplus removal position. It will be appreciated by those skilled in the art that preselection portion 770 need not be part of the third panel, but may be part of any panel, such as the ITM panel 700 shown.₁、770₂, or 770_NIt is clear that it may be part of any of the following. Additionally, the preselected portion 770 may be adjacent up to a point that does not include the ink image area 710 in the adjacent panel 700, unless a seam 800 exists between the panel comprising the preselected portion 770 and the adjacent panel. may further include a portion of panel 700, for example, if this illustration shows panel 770₄, panel 770₃and ink image area 710₄Panel 770 between₄may be included in the preselection portion 770. Additionally, although this figure and the accompanying description refer to a non-limiting example in which the preselection portion 770 is provided in whole or in part on a panel 700 having a length greater than other panels, the preselection portion 770 It is also clear that portion 770 may be provided in whole or in part on any panel 700, as long as it does not overlap sensitive areas as referred to herein. According to embodiments in which a blade change operation occurs only when preselected portion 770 traverses a surplus removal location, a blade change controller, such as blade change controller 1150 described above, may cause printing system 100 to A processor is included for executing program instructions to cause blade exchange operations to occur only during the traversal of the location.

System operation example 1

A printing system according to any of the embodiments herein includes eleven panels (i.e. N=11) and panels 11 and 1 (as shown in FIG. 13A showing the seam between panel N and panel 1). , each panel includes an ink image area, and the printing system further includes a blade changing mechanism that includes a seam between the ITM and the ink image area, such as portion 750 in panel N shown in FIG. 13A. , a blade change controller programmed to perform a blade change operation after the ink image area on panel 10 passes the surplus removal position and before the ink image area on panel 11 passes the surplus removal position. .

Example 2

The printing system according to any of the embodiments herein comprises an ITM comprising 11 panels and a seam between panel 11 and panel 1, each panel comprising an ink image area, the printing system further comprising: a blade The exchange mechanism includes a blade exchange controller programmed to enforce the rules such that the blade exchange operation occurs exactly once during each rotation of the ITM, in this example when the ink image area on panel 11 is redundant. This is done after passing the removal position and before the seam passes the surplus removal position.

As mentioned above, sensitive areas include, for example, ink image areas or seams. In embodiments, the controller uses the position and/or velocity information to determine when the non-sensitive portion passes through the redundancy removal position and initiates a blade replacement operation only based on that determination. This ensures that the portion that traverses the surplus removal location during a blade change operation is one of a plurality of predetermined portions that do not include sensitive portions. In embodiments, the method includes configuring the blade change mechanism to ensure that a blade change operation occurs only when one of a plurality of predetermined portions of the ITM, such as portion 750 of FIG. 13A, traverses the surplus removal position. Using a blade exchange controller to control. In an alternative embodiment, the controller uses the position and/or velocity information to determine when the section comprising the sensitive section passes through the redundancy removal position, initiates a blade replacement operation based on that determination, and specifically In particular, a situation is avoided in which the portion that traverses the surplus removal position during the blade replacement operation is one of a plurality of predetermined portions including sensitive portions. In embodiments, the method includes controlling a blade changing mechanism to avoid a blade changing operation occurring when one of a plurality of predetermined portions of the ITM, such as portion 760 of FIG. 13A, traverses the surplus removal position. Use a replacement controller.

In embodiments, such as, for example, the embodiment described with reference to FIG. may include program instructions to ensure that the In alternative embodiments, such as the embodiment described with reference to FIG. 17, the blade exchange controller 1150 may cause the blade exchange controller 1150 to perform a blade exchange operation when the section comprising the sensitive section passes through the surplus removal position. may include program instructions to avoid this.

FIG. 16 includes a flowchart of a method of operating a printing system including a blade exchange mechanism and a blade exchange controller, according to some embodiments, the method comprising:

a) Step S01 of forming an ink image on the surface of the rotating ITM 210 by droplet deposition, b) Step S02 of transporting the ink image to the impression station, c) Step S03 of transporting the ink image to the substrate, d) Impression station e) applying excess processing liquid to a portion of the surface of the rotating ITM downstream of the active position; step S05 in which surplus liquid is removed, leaving a treatment solution film with predetermined properties, e.g. thickness and thickness uniformity, due to the presence of a doctor blade in step S05, and f) performing a blade change operation in accordance with a control function. It includes step S06A. The control function preferably ensures that an exchange of the blade in the active position with a different blade occurs only when the part of the ITM being conveyed through the surplus removal position does not include a sensitive part. This is accomplished by a blade exchange controller that controls the operation of the blade exchange mechanism.

In other embodiments, step S06A differs from the blade in the active position only if the portion of the ITM being conveyed through the redundancy removal position is one of a plurality of predetermined "acceptable" portions of the ITM. Controlling the operation of the blade changing mechanism to ensure that an exchange with the blade occurs, ie those parts are predetermined as allowing the blade changing operation. Examples of "acceptable" portions include portion 750 in FIG. 13A.

FIG. 17 includes a flowchart of a method of operating a printing system including a blade exchange mechanism and a blade exchange controller according to an alternative embodiment, the method including step S01, which is all the same as the method illustrated in the flowchart of FIG. 16. , S02, S03, S04, and S05, and step S06B for performing a blade exchange operation according to the control function. The control function preferably controls the operation of the blade changing mechanism to avoid replacing the blade in the active position with a different blade while the portion of the ITM being transported through the redundancy removal position includes a sensitive part. It is played by a blade exchange controller.

In other alternative embodiments, step S06B is in the active position when the portion of the ITM being conveyed past the surplus removal position is one of a plurality of predetermined "unacceptable" portions of the ITM. It comprises controlling the operation of the blade changing mechanism to avoid replacing the blade with a different blade, ie those parts are predetermined as those where the blade changing operation is not allowed. Examples of predetermined "unacceptable" portions include portion 760 in FIG. 13B.

In some embodiments, not all steps of the method are necessary.

Examples of suitable apparatus for performing steps S01, S02, S03, S04 and S05 are described with reference to FIGS. 1, 2A and 2B. Examples of suitable devices for performing either step S06A or step S06B are the blade changing controller 1150 of FIG. 6, as well as a blade changing mechanism, such as the motor 1140 of FIG. 6.

In embodiments, either one of step S06A or step S06B may suitably be performed by implementing a method for performing a blade changing operation according to a control function, such as the method shown in the flowchart in FIG. The method comprises:

a) Step S07 of retrieving control function rules from computer storage. A non-exhaustive list of examples of control function rules are: i. Perform a blade change operation every X revolutions of the ITM, ii. Perform a blade change operation every Y seconds, iii. ) Perform a blade replacement operation every Z sheets, iv. Perform a blade replacement operation every XX images (XX is the number of ink images attached to the ITM, for example, or the ink transferred to the substrate. images), where X, Y, Z, and XX are all predetermined by the designer and stored in computer storage for later retrieval by the controller. A parameter that can be obtained or included in the controller's program instructions.

b) receiving position information and/or ITM rotational speed information by the blade controller from one or more input devices, e.g. an input device functioning as a locator 720 or a fixed locator 810 as described above; c) then a decision Q1 for determining whether the ITM portion passing through the redundancy removal portion comprises a sensitive portion; , made by the blade exchange controller. If the answer is yes, step S09 is executed, which involves waiting for the subsequent ITM part and returning to Q1 for the subsequent part. If the answer is no, decision Q2 is addressed.

d) Determine whether the next ITM part satisfies the conditions of the control function rules Q2. For example, if rule (i) "Perform a blade replacement operation every X rotations of the ITM" is obtained in step S07, the controller determines whether the ITM has rotated X times since the last blade replacement. decide. X may be an integer, such as 1, but in some embodiments it is not an integer. If the answer is no, step S09 is executed, which involves waiting for the subsequent part and returning to Q1 for the subsequent part. If the answer is "yes", step S10 is executed.

e) Step S10 of starting a blade changing operation by the blade changing mechanism.

In some embodiments, for example, embodiments in which the control function rules are included in the program instructions of the controller, or if the control function rules were previously obtained, for example, when the printing system was first started, obtaining (step S07 ) may be skipped. It is also clear to the person skilled in the art that the order of decisions Q1 and Q2 can be reversed without changing the effectiveness of the method. In some embodiments, decision Q1 may be skipped, and in other embodiments, both receiving (step S08) and decision Q1 may be skipped. In either of these two cases, starting (step S10) may proceed solely on the basis of a "yes" result by decision Q2. For clarity, a flowchart of a method according to an exemplary non-limiting example of an embodiment is included in FIG. 19, in which both (step S08) and decision Q1 are skipped. In this example, the control function rules may include rule (ii) "Perform blade replacement operation every Y seconds." Therefore, starting (step S10) can be done (step S08 in FIG. (as in decision Q1 in Figure 18) without the need to receive ITM part position information or to determine which ITM part is about to pass the redundancy removal position during a blade replacement operation (as in decision Q1 in Figure 18), only timing. It can be done based on.

In other embodiments, step S08 determines a plurality of predetermined "acceptable" or "unacceptable" states of the ITM using at least one of the position information and the ITM rotational speed information received from the one or more input devices. Step S10 comprises determining when one of the portions passes through a redundancy removal position, and step S10 comprises causing a blade replacement operation to occur in accordance with the determination of step S08.

Input devices such as markers and sensors or marker detectors installed in the ITM, respectively, together with corresponding sensors or marker detectors installed in the printing system, or markers installed in the ITM, and/or may track the location of the part. In an alternative embodiment, step S08 comprises receiving location information from one or more such input devices, and the method comprises step S08.1 (not shown) of calculating an ITM velocity from the location information. . A controller, such as blade exchange controller 1150, receives position and optionally velocity tracking information from the input device.

In embodiments, such as the embodiment described with reference to FIG. 20, the blade exchange controller 1150 causes the blade exchange controller 1150 to perform a blade exchange operation only when a preselected portion of the ITM passes through the redundancy removal position. Program instructions may be provided to ensure that. The pre-selected portion is preferably one of the "acceptable" portions. Alternatively or additionally, the preselected portion does not include the sensitive portion. By way of illustration, in Example 1 above, an embodiment is described in which a blade change operation is performed each time a pre-selected portion between ink image areas in adjacent panels (panels 10 and 11) passes through a redundancy removal position.

FIG. 20 includes a flowchart of a method of operating a printing system including a blade exchange mechanism and a blade exchange controller, according to some embodiments, the method comprising:

a) forming an ink image on the surface of the rotating ITM 210 by droplet deposition S11; b) transporting the ink image towards the impression station S12; c) transferring the ink image to the substrate S13; d) Step S14 of applying excess processing liquid to a portion of the surface of the rotating ITM downstream of the impression station, e) removing excess liquid from the portion of the ITM with excess processing liquid due to the presence of a doctor blade in an active position; step S15; and f) controlling the operation of the blade changing mechanism to ensure that the blade changing operation occurs only when the pre-selected portion passes through the surplus removing position. Step S16, using the controller, performs a blade replacement operation according to the control function.

In some embodiments, not all steps of the method are necessary.

Examples of suitable apparatus for carrying out steps S11, S12, S13, S14 and S15 are described with reference to FIGS. 1, 2A and 2B. An example of a suitable device for performing step S16 is the blade exchange controller 1150 of FIG. 6. In embodiments, step S16 may suitably be performed by implementing a method for implementing a method for performing a blade changing operation according to a control function, such as the method illustrated in the flowchart in FIG. The method comprises:

a) a step S17 of receiving position information and/or ITM rotational speed information from one or more input devices, such as an input device functioning as a locator 720 or a fixed locator 810 as described above; b) then a surplus removal position A determination Q3 of whether the ITM portion passing through comprises a pre-selected portion, the determination being made by the blade exchange controller using, for example, position information and/or ITM rotational speed information received from one or more input devices. It will be done. If the answer is yes, step S18 is executed, which involves waiting for the subsequent part and returning to Q3 for the subsequent part. If the answer is "no", step S19 is executed.

c) Step S19 of starting a blade changing operation by the blade changing mechanism.

In an alternative embodiment, step S17 comprises receiving position information from one or more input devices, and the method comprises step S17.1 (not shown) of calculating the ITM velocity from the position information. A controller, such as blade exchange controller 1150, receives position and optionally velocity tracking information from an input device. The controller uses the position and/or velocity information to determine when the preselected portion passes the redundancy removal position and initiates a blade replacement operation based on that determination. In embodiments, the method includes controlling a blade changing mechanism to ensure that a blade changing operation occurs only when a particular preselected portion of the ITM, such as portion 770 of FIG. 15, traverses the surplus removal position. Use a controller. In other aspects, preselected portion 770 may comprise a preselected one of a plurality of predetermined portions, such as portion 750 of FIG. 13A.

In embodiments, blade exchange controller 1150 is configured to ensure that blade exchange operations do not occur simultaneously with the transfer of ink image 711 to the substrate at impression station 216. In some embodiments, ensuring this only occurs if the substrate comprises individual sheets.

As mentioned above, if the doctor blade 2014 (as shown in FIGS. 2C and 3) or (blade 1122 is one of a plurality of blades in the coating thickness adjustment assembly 1120, such as the illustrated rotating cylinder, FIG. The tip 1125 (shown in FIGS. 3 and 6) of the doctor blade 1122 (shown in FIG. The flexible ITM 210 is pressed against the backing roller 1141. The compressibility of the surface of the backing roller 1141 and/or the extent to which the doctor blade 2014 or 1122 indents or deforms the surface of the backing roller 1141 is determined by the treatment agent 2030 on the surface of the ITM 210 in some embodiments. used as a factor in adjusting the thickness of The force applied to the ITM 210 between the doctor blade and the backing roller as well as between those two (e.g. force F1 shown in Figures 6 and 7) is the force applied to the ITM 210 between the doctor blade 2014 or the backing roller, whether it is applied from the direction of the doctor blade 2014 or 1122. Regardless of whether it is applied from the direction of the roller 1141, it helps to make the interaction of the blade with the ITM 210 effective in removing excess liquid 2030 from the surface of the ITM 210. The term "interaction" when used with blades and ITMs is used herein to intend the ITM 210 traversing the blade and/or any or all physical phenomena that result.

Local stretching of ITM210 can be caused by several factors or a combination thereof. In a non-limiting example, interaction of the doctor blade with the ITM may result in localized and/or non-uniform stretching of the ITM. This can be caused by an applied force F1, or by a frictional force between the ITM on the one hand and the doctor blade and/or backing roller on the other hand, or by a combination of the force F1 and the frictional force.

FIG. 22A shows the force F1 in an example where the force is applied from the direction of the backing roller 1141. FIG. 22B shows a force F1 of equal magnitude to force F1, but when applied from the opposite direction, ie, from the direction of the doctor blade 2014. FIG. 22C schematically shows the force FF due to friction between the ITM 210 and the blade 2014, shown here as being opposite to the direction of movement of the ITM 210 (printing direction indicated by arrow 2012).

As shown in FIG. 22D, the forces shown in FIGS. 22A, 22B, and 22C, whether singly, in combination, or in combination with other factors, as manifested by the stretched ITM portion 211, Stretching of the ITM 210 may occur near the point where the surface of the ITM 210 intersects the tip 1125 of the blade 2014. In other examples (not shown), local stretching of ITM 210 may propagate to other portions of ITM 210 that are not near the point where the surface of ITM 210 intersects tip 1125 of blade 2014.

As those skilled in the art will appreciate, the above description with reference to FIGS. 22A-D regarding the interaction of a single blade 2014 with an ITM 210 and the corresponding forces and possible stretching of the ITM 210 is similar to the description herein with reference to FIGS. 4-7. As described herein, it is equally applicable to instances where multiple blades 1122 are attached to blade rotation mechanism 1120 at a processing station.

FIG. 23 shows a printing system 100 according to an embodiment. Printing system 100 includes an ITM 210, an imaging station 212, an impression station 216, a conveyor (not shown), which may be, for example, an electric motor, to drive rotation of ITM 210, a processing station 260, and a controller 215. . Processing station 260 may be, for example, the processing station shown in FIGS. 2A or 2B, where processing station 260 is shown with a single blade 2014, or the processing station shown in FIG. 6, where coating thickness adjustment assembly 1120 is shown with multiple blades 1122. It may be any of the processing stations. The controller is configured to detect non-uniform stretching of the ITM. This can be done, for example, by calculating the local velocity of the ITM 210 by the timing of the passage of the marker 720 (as shown in Figures 8-10) between the fixed locators 810 (as shown in Figure 10), and for each pair of position detectors 810, and in particular the image This may be done by executing program instructions to record deviations from expected or standard transit times for such fixed locator pairs that may be located upstream of forming station 212 and between respective print bars 222. The program instructions are preferably stored in a non-transitory storage medium (not shown) of controller 215. The controller also preferably includes at least one computer processor configured to execute program instructions. Controller 215 may be provided solely to perform some or all of the embodiments disclosed herein, or may be a controller that also performs other functions related to the operation of printing system 100. Although not shown, it will be appreciated that the controller may be wired or wirelessly connected to other components of the printing system 100 and/or any other computing devices and/or computer networks or network components; In particular, it may also include user interfaces and storage media, such as displays and printers.

Controller 215 may be further configured to respond to the detection of non-uniform stretch of ITM 210 by modulating the timing of droplet deposition by various print bars 222 to compensate for non-uniform stretch. Modulating the timing of droplet deposition avoids ink droplet misalignment and allows imaging station 212 to produce distorted ink images, or (in a four-color printing system) colors such as cyan, magenta, yellow, and black. This is to avoid forming an image where the various ink colors do not align properly to form the ink image as intended. Modulating the timing may include depositing some ink drops earlier or later than they should occur. In some cases, the modulation may include accelerating (faster) the deposition of ink droplets in some portions of the image and decelerating (slowing) the deposition of other ink droplets within the same image.

Suitable examples of methods for detecting non-uniform stretching of an ITM and responding to detection of non-uniform stretching of an ITM include the embodiments disclosed in US2015/0042736, which is incorporated herein by reference in its entirety. include.

In some embodiments, the non-uniform stretching detected by controller 215 results from interaction of blade 2014 or 1122 with ITM 210. The nature of this interaction was described above with reference to Figures 22A-D. By design, the ITM runs continuously over the blade during normal operation of the printing system and is preferably designed to not undergo uneven stretching as a result of normal interaction with the blade. However, unforeseen events, such as misaligned or mispositioned blades, can result in abnormal or uneven stretching. For example, if the coating thickness adjustment assembly comprises multiple blades, a particular one of the blades may be misaligned or mispositioned within the coating thickness adjustment assembly, and each misalignment or a mispositioned blade may result in uneven stretching of the ITM only while in the active position for removing excess liquid from the surface of the ITM, and in such instances, the problem of misalignment does not result in uneven stretching of the ITM when other blades are in the active position. In such cases, the controller may detect and track multiple repetitive and/or periodic non-uniform stretches and report them to the user or operator of the printing system or to a file that may serve as a maintenance log. . In addition to responding by modulating the timing of ink droplet deposition each time a non-uniform stretch is detected, actions in response to multiple repeated and/or periodic non-uniform stretch detections It can be taken. An appropriate response may be to realign or adjust the particular blade that is responsible for the repeated uneven stretching. In some embodiments, the adjustment may be made automatically by the controller in conjunction with the coating thickness adjustment assembly if the coating thickness adjustment assembly is so configured; An operator may perform this function.

In some embodiments, the non-uniform stretching detected by controller 215 may be caused by the additional stress of blade changing operations. The details of the blade changing operation include that the blade changing operation can result in stretching of the ITM 210 because the blade changing operation places additional forces on the portion of the ITM 210 that passes through the processing station when the blade changing operation occurs. , has already been mentioned above.

FIG. 24 includes a flowchart of a method of operating a printing system in accordance with embodiments disclosed herein, according to some embodiments, the printing system includes a processing station downstream of an impression station and upstream of an imaging station. includes a treatment fluid applicator and a coating thickness adjustment assembly including a blade. This method comprises the following.

a) Step S101 of applying excess treatment liquid to a portion of the ITM surface.

b) The non-uniformity of the ITM is eliminated by conveying the part of the ITM (which has excess processing liquid according to step S101) through a surplus removal position where the presence of a blade removes the surplus liquid from said ITM part. Step S102 resulting in stretching.

c) Step S103 of detecting the non-uniform stretching of the ITM.

d) responsive to detecting non-uniform stretching of the ITM, modulating the timing of droplet deposition to compensate for the non-uniform stretching S104;

In some embodiments, the coating thickness adjustment assembly further comprises one or more additional blades, such that the coating thickness adjustment assembly comprises a plurality of blades, and the blade in step S102 is one of the plurality of blades. One of them. In some embodiments, the non-uniform stretching is localized, at or near the portion of the ITM that traverses the processing station. In some embodiments, not all steps of the method are necessary.

FIG. 25 includes a flowchart of a method of operating a printing system in accordance with embodiments disclosed herein, according to some embodiments, the printing system includes a processing station downstream of an impression station and upstream of an imaging station. includes a treatment fluid applicator and a coating thickness adjustment assembly including a blade. This method comprises the following.

a) Step S101A of applying excess treatment liquid to a portion of the ITM. This preferably occurs at a processing station downstream of the impression station and upstream of the imaging station.

b) conveying the portion of the ITM (having excess processing liquid due to step S101A) through a surplus removal location where the presence of the blade removes excess liquid by interaction between the blade and the ITM; Step S102A, where the interaction with results in non-uniform stretching of the ITM.

c) Step S103A of detecting the above-mentioned non-uniform stretching of the ITM.

d) responsive to detecting non-uniform stretching of the ITM caused by interaction between the blade and the ITM, modulating the timing of droplet deposition to compensate for the non-uniform stretching S104A;

In some embodiments, the coating thickness adjustment assembly further comprises one or more additional blades, such that the coating thickness adjustment assembly comprises a plurality of blades, and the blade in step S102A is one of the plurality of blades. One of them. In some embodiments, the non-uniform stretching is localized, at or near the portion of the ITM that traverses the processing station. In some embodiments, not all steps of the method are necessary. In other embodiments, local stretching of the ITM may propagate to other portions of the ITM that are not at or near the portion of the ITM that traverses the processing station.

FIG. 26 includes a flowchart of a method of operating a printing system according to any of the embodiments herein, according to some embodiments, the printing system includes a processing station downstream of an impression station and upstream of an imaging station. a treatment fluid applicator and a coating thickness adjustment assembly comprising a plurality of blades and a blade changing operation to change which blade interacts with the ITM to remove excess treatment fluid from the surface of the ITM; and a blade exchange mechanism for performing. This method comprises the following.

a) Step S111 using a blade changing mechanism to perform a blade changing operation.

b) detecting, during a blade change operation, local stretching of a portion of the ITM that intersects the processing station or is in the vicinity of the portion of the ITM that passes through the processing station, the local stretching being at least partially step S112 caused by the blade replacement operation.

c) Step S113 of responding to the detection of local stretching of the ITM by modulating the timing of droplet deposition to compensate for the local stretching of the ITM.

In some embodiments, the modulation of step S113 may be delayed by the travel time of the non-uniformly stretched portion of the ITM between the processing station and the imaging station.

The invention has been described using detailed descriptions of embodiments of the invention, which are provided by way of example and are not intended to limit the scope of the invention. The described embodiments include various features, not all of which are necessary in all embodiments of the invention. Some embodiments of the invention use only some of the possible features or combinations of features. Variations of the described embodiments of the invention and combinations of the various features described in the described embodiments will occur to those skilled in the art to which the invention pertains.

In the foregoing description and claims of this disclosure, each of the verbs "comprise," "comprise," and "having" and their conjugations are used to mean that one or more objects of the verb are not necessarily one or more of the verbs. or used to indicate a non-exhaustive list of members, components, elements, or parts of a plural subject. As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. For example, the term "mark" or "at least one mark" may include multiple marks.