Image forming device

The present invention relates to an image forming apparatus, and more particularly to a recording control technique in an image forming apparatus in which droplets are dropped onto a recording medium to form an image with dots.

Conventionally, as an image forming apparatus, an inkjet recording apparatus (inkjet printer) having an inkjet head (ink ejection head) in which a large number of nozzles are arranged has been known. In this inkjet recording device, an image is formed by ejecting ink as droplets from a nozzle and forming dots on the recording medium while moving the inkjet head and the recording medium relative to each other.

Various methods have been conventionally known as ink ejection methods in such an inkjet recording apparatus. For example, the diaphragm forming a part of the pressure chamber (ink chamber) is deformed by the deformation of the piezoelectric element (piezoelectric actuator) to change the volume of the pressure chamber, and when the volume of the pressure chamber is increased, the pressure chamber is changed from the ink supply path to the pressure chamber. Inkjet is introduced into the pressure chamber, and when the volume of the pressure chamber decreases, the ink in the pressure chamber is ejected as droplets from the nozzle. A thermal inkjet method for discharging is known.

As described above, in the inkjet recording device, one image is expressed by combining the dots formed by the ink ejected from the nozzle. High image quality is achieved by reducing the size of these dots, increasing the density, and increasing the number of pixels per image.

However, by increasing the density of dots, adjacent or overlapping ink droplets (dots) on the recording medium may bleed or color mixing may occur, and the quality deteriorates when bleeding or color mixing occurs. there were.

Therefore, various proposals have been made conventionally to prevent such ink bleeding and color mixing. For example, a recording head makes a recording liquid having an electrorheological effect into droplets and attaches the recording liquid to an intermediate transfer medium in which an electric field is formed on the surface, thereby increasing the viscosity of the droplets on the transfer medium and causing the recording liquid to become. There is known a recording device capable of high-quality printing by preventing excessive spread of the recording head and color mixing by transferring to a transfer medium in a thickened state (see, for example, Patent Document 1 and the like).

Further, for example, a recording head is used to atomize a recording liquid having an electrorheological effect and adhere it onto a transfer target on which an electric field is formed, thereby instantly increasing the viscosity or yield value of the adhered recording droplets. There is known a recording device capable of high-quality printing by preventing whiskers, bleeding, and color mixing of recording dots (see, for example, Patent Document 2 and the like).<patcit num="1"><text>Japanese Unexamined Patent Publication No. 5-4342</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 5-4343</text></patcit>

<p> However, in the recording apparatus described in Patent Document 1, it takes time to dry the recording droplets on the intermediate transfer medium, which causes a decrease in the recording speed, and in the transfer in the electric field application state, the transfer is performed. There is a problem that the subsequent bleeding cannot be controlled.</p><p> Similarly, in the recording apparatus described in Patent Document 2, although the speed of bleeding of recording dots can be suppressed by applying an electric field, bleeding of recording dots occurs for a long time after the electric field is removed. There is a problem that it progresses.</p><p> Further, in any of the above cases, it is disclosed that bleeding of recording dots can be prevented by applying an electric field to a recording droplet having an electrorheological effect. There is no disclosure about the method of optimally controlling the permeation rate of the recording droplets into the recording medium according to the situation, and there is no description about the relationship between the permeation of the recording dots and the bleeding of the recording medium or the recording droplets. Depending on the type, there is a problem that it is not possible to optimally control the blurring of recording dots.</p><p> The present invention has been made in view of such circumstances, and the penetration rate of the recording droplets into the recording medium is optimally controlled according to the type of the recording medium and the recording droplets (ink) to prevent bleeding. An object of the present invention is to provide an image forming apparatus capable of performing high-quality image recording.</p>

<p> In order to achieve the above object, the invention according to claim 1 comprises a droplet ejection head that ejects a liquid having an electroviscosity effect as droplets toward a recording medium, and droplets that have landed on the recording medium. An electric field applying means for applying an electric field to the recording medium, a recording medium type detecting means for detecting the type of the recording medium, and permeation of droplets landed on the recording medium into the recording medium according to the detection result of the recording medium. An image characterized by comprising an electric field strength controlling means for controlling the electric field strength of the electric field applied to the droplets landed on the recording medium so that the velocity becomes a predetermined permeation rate. A forming device is provided.</p><p> According to this, since the ink droplets landing on the recording medium are controlled to have the desired ink penetration rate according to the type of the recording medium, the ink bleeding into the recording medium is prevented and the recording is performed. Optimal image formation according to the type of medium is possible.</p><p> Further, as shown in claim 2, the image forming apparatus according to claim 1, further, the liquid is a radiation curable liquid, and the droplets landed on the recording medium are irradiated with radiation. It has a radiation irradiating means for curing and fixing, and is characterized in that an electric field is applied to the landed droplets by the electric field applying means and radiation is irradiated by the radiation irradiating means.</p><p> According to this, the viscosity of the droplet becomes high due to the application of an electric field, the penetration rate becomes slow, and the droplet existing on the surface of the recording medium can be cured on the surface of the recording medium by irradiation, and the bleeding of the droplet can be prevented. It can be reliably prevented.</p><p> Further, as shown in claim 3, the recording medium type detected by the recording medium type detecting means cures the droplets mainly on the surface of the recording medium and finally fixes the dye on the surface of the recording medium. In the case of a surface-fixing medium, the viscosity of the droplets landed on the recording medium is increased to a predetermined ratio or less of the amount of the droplets landed on the recording medium until the curing by the radiation is completed. It is characterized in that the electric field strength applied to the droplets by the electric field applying means is controlled by the electric field strength controlling means so that the amount of the droplets permeates into the recording medium.</p><p> According to this, when the recording medium is a surface-fixing type medium in which droplets are cured and fixed on the surface of the recording medium, the amount of droplet penetration until the droplets are cured by irradiation is set to a predetermined ratio or less. Since the permeation rate of the droplet is controlled, it is possible to cure and fix the droplet while suppressing the degree of bleeding within an allowable range.</p><p> Further, as shown in claim 4, the permeation droplet amount of the predetermined ratio or less is set according to the type of the recording medium. Thereby, the optimum permissible permeation amount can be set according to the type of the recording medium.</p><p> Further, as shown in claim 5, the predetermined ratio is 30%. This makes it possible to handle most recording medium types.</p><p> Further, as shown in claim 6, when different landing droplet amounts are mixed in the image, the predetermined permeation rate is set based on the representative landing droplet amount which is the predetermined representative value in the image. It is characterized by that. This makes it possible to reduce the control load even for a complicated image.</p><p> Further, as shown in claim 7, the representative landing droplet amount is the minimum landing droplet amount. In this way, the highest image quality can be obtained by determining the representative value under the most severe conditions.</p><p> Further, as shown in claim 8, the electric field strength control means includes the amount of irradiation energy by the radiation irradiation means, the transfer speed at which the recording medium is relatively conveyed with the droplet ejection head, and the amount of landed droplets. A permeation rate calculation unit that calculates the predetermined permeation rate, a first storage unit that stores the correlation data between the liquid viscosity and the permeation rate, and a second storage unit that stores the correlation data between the electric field strength and the liquid viscosity. The electric field strength calculation unit has an electric field strength calculation unit for calculating the electric field strength, and the electric field strength calculation unit correlates the predetermined permeation speed calculated by the permeation speed calculation unit with the correlation data of the first storage unit and the second storage unit. It is characterized in that a predetermined electric field strength is calculated from the data.</p><p> This makes it possible to easily calculate the desired electric field strength by storing and setting the data in advance.</p><p> Further, as shown in claim 9, the electric field strength control means includes the amount of irradiation energy by the radiation irradiation means, the transfer speed at which the recording medium is relatively conveyed with the droplet ejection head, and the amount of landed droplets. The permeation speed calculation unit that calculates the predetermined permeation rate, the electric field strength applied to the droplet, and the permeation rate of the droplet into the recording medium, which is determined by the type of the droplet and the type of the recording medium. It is characterized by having an electric field strength calculation unit that calculates a predetermined electric field strength from the correlation data with. Thereby, the optimum electric field can be applied in consideration of the relationship between the recording medium and the permeation rate.</p><p> Further, as shown in claim 10, the image forming apparatus according to claim 1 or 2, further, the recording medium type detected by the recording medium type detecting means has droplets in the image receiving layer in the recording medium. In the case of a permeation-fixing medium in which the dye is fixed in the image receiving layer by penetrating into the recording medium, the electric field strength control means permeates the recording medium in a state where the viscosity of the droplets landing on the recording medium is low. It is characterized in that it is controlled in such a manner. According to this, in the case of a permeation-fixing type medium in which the recording medium permeates the droplets and fixes them in the image receiving layer, since there is no bleeding in the image receiving layer, the viscosity of the droplets is increased without applying an electric field. Optimal images can be formed by allowing them to penetrate quickly in a low state.</p>

<p> As described above, according to the image forming apparatus according to the present invention, the penetration rate of the ink into the recording medium is optimally controlled according to the type of the recording medium and the recording droplet (ink) to prevent bleeding. It is possible to record high-quality images.</p><p> Further, particularly in the case of a surface-fixing type medium, a radiation-curable ink is used, and the penetration rate is controlled so that the ink penetration amount becomes a predetermined ratio or less by the time the ink curing on the surface of the recording medium is completed. In this case, the degree of bleeding can be suppressed within an allowable range and cured on the surface of the recording medium, and a high-quality image can be formed.</p>

Hereinafter, the image forming apparatus according to the present invention will be described in detail with reference to the attached drawings. The image forming apparatus of the present embodiment prevents bleeding of recording dots by controlling the penetration rate of the recording dots dropleted on the recording medium into the recording medium according to the recording medium (image receiving layer). , It is designed to form the optimum image.

FIG. 1 is an overall configuration diagram of an inkjet recording device as an image forming device according to an embodiment of the present invention. As shown in FIG. 1, the inkjet recording apparatus 10 has a printing unit 12 having a printing head (ink ejection head) for ejecting ink, and an ink for storing ink to be supplied to the printing unit 12. The storage / loading unit 14, the paper feed unit 18 that supplies the recording paper (recording medium) 16, the decal processing unit 20 that removes the curl of the recording paper 16, and the nozzle surface (ink ejection surface) of the print head of the printing unit 12. ), A suction belt transport unit 22 that transports the recording paper 16 while maintaining the flatness of the recording paper 16, a print detection unit 24 that reads the print result by the print unit 12, and printed (printed) completed. It is provided with a paper ejection unit 26 for ejecting the recording paper (printed matter) of the above.

In FIG. 1, a magazine of roll paper (continuous paper) is shown as an example of the paper feed unit 18, but a plurality of magazines having different paper widths, paper qualities, and the like may be provided side by side. Further, the paper may be supplied by a cassette in which cut paper is laminated and loaded, instead of or in combination with the roll paper magazine.

An information recorder 18a such as a bar code or a wireless tag that records paper type information is attached to the magazine of the paper feed unit 18. The information of the information recording body 18a is read by the medium type detecting means 60, the type of the recording paper 16 used is automatically determined, and appropriate ink ejection according to the type of the recording paper 16 is realized. In addition to the ink ejection control as described above, the penetration speed of the recording dots is optimally controlled according to the type of the recording paper 16, which will be described in detail later.

The recording paper 16 sent out from the paper feed unit 18 has a curl due to being loaded in the magazine. In order to remove this curl, in the decal processing unit 20, heat is applied to the recording paper 16 by the heating drum 30 in the direction opposite to the curling direction of the magazine. At this time, it is more preferable to control the heating temperature so that the printed surface of the recording paper 16 has a slightly weak curl on the outside.

In the case of an apparatus configuration using roll paper, as shown in FIG. 1, a cutter (first cutter) 28 for cutting is provided, and the roll paper is cut to a desired size by the cutter 28. The cutter 28 is composed of a fixed blade 28A having a length equal to or longer than the transport path width of the recording paper 16 and a round blade 28B that moves along the fixed blade 28A, and the fixed blade 28A is provided on the back side of printing. The round blade 28B is arranged on the printing surface side across the transport path. When using cut paper, the cutter 28 is unnecessary.

After the decal processing, the cut recording paper 16 is sent to the suction belt transport unit 22. The suction belt transport unit 22 has a structure in which an endless belt 33 is wound between the rollers 31 and 32, and is at least a portion facing the nozzle surface of the print head of the print unit 12 and the sensor surface of the print detection unit 24. Is configured to form a flat surface.

The belt 33 has a width dimension wider than the width of the recording paper 16, and a large number of suction holes (not shown) are formed on the belt surface. As shown in FIG. 1, the suction chamber 34 is located inside the belt 33 spanned between the rollers 31 and 32 at a position facing the nozzle surface of the print head of the print unit 12 and the sensor surface of the print detection unit 24. The recording paper 16 on the belt 33 is sucked and held by sucking the suction chamber 34 with the fan 35 to create a negative pressure.

The belt 33 is driven in the clockwise direction on FIG. 1 by transmitting the power of the motor 37 to at least one of the rollers 31 and 32 around which the belt 33 is wound, for example, in the example shown in FIG. , The recording paper 16 held on the belt 33 is transported from left to right at a transport speed V, as shown by an arrow in FIG. Further, the drive of the motor 37 is controlled by the transport control means 62, and the transport speed V set by the transport control means 62 is used for calculating the optimum penetration speed of the recording dots, which will be described later.

When printing a borderless print or the like, ink also adheres to the belt 33. Therefore, the belt cleaning unit 36 is provided at a predetermined position (appropriate position other than the printing area) on the outside of the belt 33. Although the configuration of the belt cleaning unit 36 is not shown in detail, for example, there are a method of niping a brush roll, a water absorption roll, etc., an air blow method of blowing clean air, or a combination thereof. In the case of the method of niping the cleaning roll, the cleaning effect is large when the belt wire speed and the roller wire speed are changed.

It is conceivable to use a roller / nip transfer mechanism instead of the suction belt transfer unit 22, but when the roller / nip transfer is performed in the print area, the roller comes into contact with the printed surface of the paper immediately after printing, so that the image tends to blur. There is a problem. Therefore, as in this example, it is preferable to carry the suction belt so that the image surfaces do not come into contact with each other in the print area.

A heating fan 40 is provided on the upstream side of the print head 12 on the paper transport path formed by the suction belt transport section 22. The heating fan 40 blows heating air onto the recording paper 16 before printing to heat the recording paper 16. By heating the recording paper 16 immediately before printing, the ink can be easily dried after landing.

The printing unit 12 is a so-called full-line type head in which a line-type head having a length corresponding to the maximum paper width is arranged in a direction orthogonal to the paper feed direction. A detailed structural example will be described later, but printing is performed. In part 12, a line-type head in which a plurality of ink ejection ports (nozzles) are arranged over a length exceeding at least one side of the maximum size recording paper 16 to be printed by the inkjet recording apparatus 10 is used for black for each color. The print head 12K, the cyan print head 12C, the magenta print head 12M, and the yellow print head 12Y are arranged in parallel.

As shown in FIG. 1, the ink storage / loading unit 14 has tanks for storing inks of colors corresponding to the print heads 12K, 12C, 12M, and 12Y constituting the printing unit 12, and each tank is shown in the drawing. It communicates with each print head via an omitted pipeline. Further, the ink storage / loading unit 14 is provided with notification means (display means, warning sound generation means) for notifying when the remaining amount of ink is low, and also has a mechanism for preventing erroneous loading between colors. ing.

The print detection unit 24 includes an image sensor for capturing the drip result of the print unit 12, and functions as a means for checking nozzle clogging and other ejection defects from the drip image read by the image sensor.

The print detection unit 24 of the present embodiment is composed of a line sensor having a light receiving element array wider than the ink ejection width (image recording width) of at least the print heads 12K, 12C, 12M, and 12Y. This line sensor includes an R sensor array in which photoelectric conversion elements (pixels) provided with a red (R) color filter are arranged in a line, and a G sensor array in which a green (G) color filter is provided. It consists of a color separation line CCD sensor consisting of a B sensor array provided with a blue (B) color filter. Instead of the line sensor, it is also possible to use an area sensor in which light receiving elements are arranged two-dimensionally.

The print detection unit 24 reads the test patterns printed by the print heads 12K, 12C, 12M, and 12Y of the print unit 12, and detects the ejection of each print head. The ejection determination includes the presence / absence of ejection, the measurement of the dot size, the measurement of the dot landing position, and the like. Further, the print detection unit 24 includes a light source for irradiating the dropped dots with light.

A heating / pressurizing unit 44 is provided after the print detection unit 24. The heating / pressurizing unit 44 is a means for controlling the glossiness of the image surface, and pressurizes the image surface with a pressurizing roller 45 having a predetermined surface uneven shape while heating the image surface to transfer the uneven shape to the image surface. To do.

The printed matter thus generated is discharged from the paper ejection unit 26. When the main image (printed with the target image) and the test print are formed in parallel on a large sheet of paper at the same time, the test print portion is separated by the cutter (second cutter) 48. The cutter 48 is provided immediately before the paper ejection section 26, and is for cutting the main image and the test printing section when test printing is performed on the image margin section. The structure of the cutter 48 is the same as that of the first cutter 48 described above, and is composed of a fixed blade 48A and a round blade 48B.

Further, although not shown in FIG. 1, a sorter for accumulating images for each order is provided in the output section 26 of this image.

The inkjet recording apparatus 10 of the present embodiment will be described in detail later, but depending on the type of recording paper 16, it is electrically viscous to radiation-curable ink such as UV ink (ultraviolet curable ink) or EB ink (electron beam curable ink). Using an ink that has an effect, a voltage is applied to this ink to change its viscosity, and the penetration rate into the recording paper 16 is optimally controlled to prevent bleeding. Therefore, in addition to the above-mentioned ones, it has the following configurations. The radiation referred to here as a radiation-curable ink includes electromagnetic radiation such as ultraviolet rays (UV) and particle beams such as electron beams.

That is, in addition to the above, the inkjet recording apparatus 10 has an ink type detecting means 64, an electrode 66 as an electric field applying means for applying an electric field to the ink landed on the recording paper 16, and an electric field strength controlling means 68 for controlling the electrode 66. The ink has a UV light source 70 as a photopolymerization irradiation means for irradiating the ink landed on the recording paper 16 with UV light to cure and fix the ink, and an irradiation control means 72 for controlling the UV light source 70. The electrode 66 and the UV light source 70 are arranged on the downstream side of each print head 12K, 12C, 12M, and 12Y, respectively. In addition, depending on the type of recording paper 16, the ink viscosity is kept low and the ink is quickly permeated and fixed. At this time, the droplet interval (dropping timing) is set so that adjacent recording dots do not cause landing interference (color mixing). Therefore, it has a drip control means 74. Details of these detection means, control means, and the like will be described later.

Next, the structure of the print head of the print unit 12 will be described. The printing unit 12 is provided for each color of ink. The print head is composed of print heads 12K, 12C, 12M, and 12Y that eject ink of each color of K (black), C (cyan), M (magenta), and Y (yellow). Since they are common to each other, they will be described below as the print head 50 as shown in FIG. 2 as a representative.

FIG. 2 is a plan perspective view showing the structure of the print head 50. As shown in FIG. 2, the print head 50 is configured by two-dimensionally staggering the pressure chamber unit 54 composed of the pressure chamber 52 having the nozzle 51 and the ink supply port 53.

As shown in FIG. 2, the pressure chamber 52 provided corresponding to each nozzle 51 has a substantially square planar shape, and the nozzle 51 and the ink supply port 53 are provided at both diagonal corners. Has been done. Each pressure chamber 52 communicates with an ink common flow path (not shown in FIG. 2) via an ink supply port 53.

FIG. 2 is a plan perspective view, in which the nozzle 51 is opened toward the back side of the paper surface in the figure, and the lower side of the print head 50 in the figure is directed toward the recording paper 16 conveyed in the arrow S direction in the figure. Ink is ejected from the nozzle 51 (on the back side of the figure). Further, as shown in FIG. 2, the print head 50 is a line head that can correspond to the maximum paper width of the recording paper 16 with the arrow M direction orthogonal to the transport direction (arrow S direction) of the recording paper 16 as the longitudinal direction. ..

As described above, according to the printing unit 12 having the printing head 50 which is a full-line type head covering the entire width of the recording paper 16, the recording paper 16 is conveyed in the transport direction (secondary scanning direction) indicated by the arrow S. An image can be recorded on the entire surface of the recording paper 16 by performing the operation of relatively moving the printing unit 12 and the printing unit 12 only once (that is, in one sub-scanning). As a result, high-speed printing is possible and productivity is improved as compared with the shuttle type head in which the print head 50 reciprocates in the direction indicated by the arrow M (main scanning direction) in FIG. 2 orthogonal to the transport direction of the recording paper 16. Can be made to.

The main scan and the sub scan will be described here. The main scan and the sub scan refer to the method of driving the nozzles in the print head, and are defined as follows.

That is, in a full-line head having a nozzle row corresponding to the entire width of the paper (recording paper 16), when driving the nozzles, (1) all the nozzles are driven at the same time, and (2) the nozzles are driven from one side to the other side. There are driving methods such as sequential drive, (3) dividing the nozzle into blocks, and sequentially driving from one side to the other for each block, and one line in the width direction of the paper (direction orthogonal to the paper transport direction). Driving a nozzle that prints (a line consisting of one row of dots or a line consisting of multiple rows of dots) is defined as main scanning.

For example, as shown in FIG. 2, when driving the nozzles 51 in the print head 50 in which the nozzles 51 are arranged in a two-dimensional matrix, the main scan as described in (3) above is preferable. That is, in FIG. 2, the nozzles 51-11, 51-12, ..., 51-16, and the nozzles 51-21, ..., 51-26, which form each row arranged in a two-dimensional matrix. , And nozzles 51-31, ..., 51-36, ..., etc. are each one block, and while the recording paper 16 is conveyed in the direction of the arrow S in the figure, the nozzles in each block are transferred to the recording paper 16 From Nozzle 51-11, Nozzle 51-21, Nozzle 51-31, ... to Nozzle 51-16, Nozzle 51-26, 51-36, ..., etc. By sequentially driving, the recording dots ejected from each nozzle 51 are printed on the recording paper 16 as one line in the recording paper width direction (arrow M direction orthogonal to the conveying direction, main scanning direction).

On the other hand, by moving the print head and the recording paper relative to each other, printing of one line (a line consisting of one row of dots or a line consisting of a plurality of rows of dots) formed by the main scanning is repeatedly performed. Nozzle drive is defined as sub-scanning.

Further, FIG. 3 shows a cross-sectional view of the pressure chamber unit 54 along the line III-III in FIG.

As shown in FIG. 3, in the pressure chamber unit 54, an actuator 58 provided with an individual electrode 57 is joined to a pressure plate (diaphragm) 56 constituting the top surface of the pressure chamber 52, and the individual electrode 57 is attached. By applying a driving voltage to the actuator 58, the actuator 58 is deformed so that ink is ejected from the nozzle 51.

Further, when the ink is ejected from the nozzle 51, new ink is supplied to the pressure chamber 52 from the ink common flow path 55 through the ink supply port 53.

In the present embodiment, the print head 50 will be described as a full-line head in which nozzles 51 (pressure chamber unit 54) are arranged in a two-dimensional matrix as shown in FIG. 2, but as shown in FIG. The short two-dimensionally arranged heads 50'may be arranged in a staggered pattern and joined together to have a length corresponding to the entire width of the recording paper 16.

FIG. 5 is a block diagram of a main part showing the system configuration of the inkjet recording apparatus 10. The inkjet recording device 10 includes a communication interface 78, a system controller 80, an image memory 82, a transport control means 62, a print control unit 86, an image buffer memory 88, a head driver 90, and the like.

The communication interface 78 is an interface unit that receives image data sent from the host computer 76. A serial interface such as USB, IEEE1394, Ethernet, or wireless network or a parallel interface such as Centronics can be applied to the communication interface 78. A buffer memory (not shown) for speeding up communication may be mounted on this portion. The image data transmitted from the host computer 76 is taken into the inkjet recording device 10 via the communication interface 78, and is temporarily stored in the image memory 82. The image memory 82 is a storage means for temporarily storing an image input via the communication interface 78, and data is read / written through the system controller 80. The image memory 82 is not limited to a memory composed of semiconductor elements, and a magnetic medium such as a hard disk may be used.

The system controller 80 is a control unit that controls each unit such as the communication interface 78, the image memory 82, and the transport control means 62. The system controller 80 is composed of a central processing unit (CPU) and its peripheral circuits, etc., controls communication with the host computer 76, controls reading and writing of the image memory 82, and controls the motor 37 of the transport system. Generate a control signal. The transport control means 62 controls the drive of the motor 37 according to an instruction from the system controller 80.

The print control unit 86 is a signal control unit that performs various processing, correction, and the like for generating a signal for print control from the image data in the image memory 82 under the control of the system controller 80. The print control unit 86 performs necessary signal processing, and controls the ejection amount and ejection timing of ink droplets of the print head 50 via the head driver 90 based on the image data. As a result, a desired dot size and dot arrangement are realized.

The print control unit 86 is provided with an image buffer memory 88, and data such as image data and parameters are temporarily stored in the image buffer memory 88 when the print control unit 86 processes image data. Although the image buffer memory 88 is shown in FIG. 4 in a mode attached to the print control unit 86, it can also be used as the image memory 82. It is also possible to integrate the print control unit 86 and the system controller 80 into a single processor.

Further, as described above, the inkjet recording apparatus 10 of the present embodiment also has a medium type detecting means 60 for detecting the type of recording paper 16, an ink type detecting means 64 for detecting the type of ink, and an electroviscosity effect. An electric field strength control means 68 that controls an electrode 66 that applies an electric field to the ink to change its viscosity, an irradiation control means 72 that controls a UV light source 70 that irradiates UV ink, which is a radiation-curable ink, with UV light, and an adjacent recording. It has a drip control means 74 that controls the drip timing so that color mixing does not occur between dots.

Each of these detection means and control means is controlled by the system controller 80, and in particular, the drip control means 74 is provided in the print control unit 86.

In the inkjet recording apparatus 10 of the present embodiment, when the type of recording medium (recording paper 16) is a surface-fixing medium and the ink used is a UV-curable ink having an electroviscosity effect, the ink landed on the recording medium is used. An electric field is applied to change the viscosity of the ink (thickening the ink) to control the penetration rate of the ink into the recording medium, and UV curing is performed in the presence of ink droplets on the surface to prevent bleeding. On the other hand, when the type of recording medium is a penetration-fixing type medium, the landed ink is not applied with an electric field, and the ink is quickly penetrated and fixed in a state where the viscosity of the ink is low. At this time, the drip timing (drip interval) is controlled between adjacent recording dots to prevent landing interference.

Here, the surface-fixing medium refers to a recording medium in which the ink is mainly cured on the surface of the recording medium and the dye is finally fixed on the surface of the recording medium, and for example, plain paper is applicable. .. In the case of a surface-fixing medium, the ink does not penetrate at all, and some ink may penetrate inside the recording medium. The permeation-fixing medium is a medium in which ink is permeated into the image-receiving layer in the recording medium to fix the dye (solute) in the image-receiving layer, and the dye is finally fixed in the image-receiving layer. A recording medium, for example, inkjet paper. At this time, when the ink is an aqueous solvent, the solvent finally evaporates by drying.

As described above, the type of the recording medium (recording paper 16) is detected by the medium type detecting means 60 by reading the information from the information recording body 18a attached to the magazine of the paper feeding unit 18. The ink type is detected by the ink type detecting means 64. These detection methods are not particularly limited, and various methods can be applied. For example, in the case of ink, as with the recording medium, the ink type information attached to the ink tank mounted on the ink storage / loading unit 14 may be read from the recorded information recorder, or separately. It may be input by the operator.

Further, the electrorheological effect ink used here has an effect of momentarily increasing the apparent viscosity by applying an electric field (applying a voltage) (this is called an electrorheological effect). It is an ink that has, and its viscosity changes reversibly depending on whether the electric field is turned on or off. There are two types of electrorheological effect fluids having such an electrorheological effect, a dispersed type and a uniform system.

In the dispersed type, dielectric fine particles are dispersed in a liquid in an electrically insulating solvent. In a state where no electric field is applied, the fine particles remain dispersed and have low viscosity, but an electric field is used. When is applied, polarized particles form a chain structure (bridge) connected in the direction of the electric field, and this bridge acts to increase the viscosity of the fluid, so that the viscosity of the fluid increases. .. Dispersed electrorheological fluids include hydrous and non-hydrous systems.

Further, in a homogeneous system, molecules and domains are oriented in the electric field direction and exhibit anisotropy, such as liquid crystal. At present, uniform electrorheological fluids have little change in viscosity, so it is considered that distributed electrorheological fluids are suitable for inkjet printer applications.

Further, in the present embodiment, a radiation-curable ink (UV-curable ink or the like) is used, and such an ink is provided with an electrorheological effect. As a method for producing an ink in which the electrorheological ink has an electrorheological effect as described above, for example, solid fine particles (silica, starch, dextrin, carbon, gypsum, gelatin) in a liquid containing at least a radiation curable monomer and a polymerization initiator are used. , Alumina, cellulose, mica, zeolite, kaolite, etc.), the method of using the pigment fine particles themselves as a dispersant for the electrorheological effect, or the method of microencapsulating the dye or pigment and insulating the surface thereof. A method of using it as a dispersant for the electrorheological effect, or a method of mixing a uniform electrorheological fluid can be considered.

When the recording medium is a surface-fixing type, the penetration speed is such that the ink landed on the recording medium is fixed on the surface of the recording medium and the landed ink does not permeate the recording medium more than a predetermined amount in order to prevent bleeding. To control. Here, the ink penetration rate means the amount of ink droplets that permeate into the recording medium in a unit time when the ink droplets that land on the recording medium permeate the recording medium.

The penetration rate is controlled by controlling the electric field strength applied by the electrode 66 to the ink having an electrorheological effect that has landed on the recording paper 16 to control the viscosity of the ink. At this time, the electric field strength control means 68 calculates the optimum penetration rate, and the electric field strength of the electric field applied by the electrode 66 is controlled so that the ink viscosity corresponds to the optimum penetration rate.

In the example shown in FIG. 1, the electrode 66 that applies an electric field is installed on the downstream side of the printing unit 12 so as to apply an electric field after the ink has landed. However, the electrode 66 is provided on the upstream side of the printing unit 12. An electric field may be applied to the recording paper 16 before the ink lands. However, since it is possible that the ink in the nozzle 51 thickens due to the influence of the electric field and causes nozzle clogging, it is preferable to provide the ink on the downstream side as shown in FIG.

A static elimination means may be provided on the downstream side of the electrode 66. As a result, it is possible to prevent the recording paper 16 from being charged and becoming difficult to separate from the belt 33, which hinders transportation. Further, in this static elimination means, instead of installing a special means for this purpose, for example, the transport roller or the like is provided with conductivity so that the static elimination means can be naturally removed during the transport, and the static elimination means is provided by the transport roller or the like. It may be used in combination.

Further, when the recording medium is a permeation fixing type, the viscosity is lowered without applying an electric field so that the recording medium is quickly permeated and fixed. At this time, the drip timing is controlled by the drip control means 74 in order to prevent the landing interference of the adjacent recording dots.

Next, these electric field strength control and drip timing control will be described. First, the electric field strength control in the electric field strength control means 68 will be described.

FIG. 6 is a block diagram showing details of the electric field strength control means 68. As shown in FIG. 6, the electric field strength control means 68 includes a penetration rate calculation unit 102, an ink viscosity and penetration rate correlation data storage unit (first storage unit) 104, and an electric field strength and ink viscosity correlation data storage unit (second storage unit). The storage unit) 106 and the electric field strength calculation unit 108 are included.

The penetration speed calculation unit 102 calculates a desired optimum penetration speed from the amount of UV (photopolymerization) irradiation energy, the recording medium transport speed, and the amount of landed ink droplets. Therefore, when the penetration speed calculation unit 102 receives the image data from the image memory 82 via the system controller 80, the penetration speed calculation unit 102 calculates the amount of landing ink droplets from this, and also conveys the amount of UV irradiation energy from the irradiation control means 72. The recording medium transport speed is received from the control means 62.

Here, the desired optimum value of the ink penetration rate is a state in which the ink droplets 112 that have landed on the recording paper 16 are present on the surface of the recording paper 16 as shown in FIG. 7 (a). Since it is necessary to complete the UV curing, the amount of ink droplets 112b that have penetrated the recording paper 16 within the time from the ink landing to the end of the UV curing is shown in FIG. 7 (b), as shown in FIG. 7 (b). It is preferable that the penetration rate is 30% or less of the landed ink droplets 112 in (a) so that the amount of the ink droplets 112a remaining on the surface of the recording paper 16 is 70% or more of the landed ink droplets 112.

At this time, the results of observing and evaluating the bleeding when the ratio of the ink droplets 112b permeating the recording paper 16 among the ink droplets 112 were changed by controlling the ink permeation rate are shown in Table 1 as shown below. .. As shown in Table 1, when the ratio of the penetrating ink amount to the landing ink amount is 30% or less, bleeding is not visible, and especially when the ratio of the penetrating ink amount is 15%, a magnifying glass with a magnification of 10 times is used. Even when used, almost no bleeding was observed. On the contrary, it was found that bleeding became visible when the ratio of the penetrating ink amount exceeded 30%, and the degree of bleeding increased as the ratio of the penetrating ink amount increased.

<tables num="1"><img file="JP2005297552A_D0001.tif" /></tables>

In this way, by setting the amount of the ink droplet 112b that has penetrated the recording paper 16 to 30% or less of the amount of the ink droplet 112 that has landed, the bleeding can be made invisible. More preferably, the amount of the penetrating ink droplet 112b is 15% or less of the amount of the landed ink droplet 112.

Such an optimum penetration rate Vo [pl / sec] is calculated as follows. That is, the amount of landing ink droplets of the representative dots in the image calculated from the image data is Vd [pl], the transport speed of the recording medium received from the transport control means 62 is V [mm / sec], and the ink landing shown in FIG. The distance from to the end of the curing process (abbreviated as the distance from the printing unit 12 to the end of the UV light source 70) is L [mm], and the time from landing to the completion of curing by the UV light source 70 is t._cLet it be [sec]. However, t_cL and V are set so that &lt;L / V. This t_cIs t_cIt is a function of = f (E, V, Vd) and is determined by the UV irradiation energy amount E, the transport speed V, and the landing ink droplet amount Vd.

At this time, the permissible permeation rate Vo of the ink for the permeation amount into the recording paper 16 to be 30% or less of the ink droplet amount at the time of ink landing is calculated by the following equation (1).

Vo = 0.3 × Vd / t_c (1) Therefore, Vo = 0.3 × Vd / t_cThe electric field strength may be controlled so as to obtain the following optimum penetration rate.

In the above calculation, the landing ink droplet amount Vd of the representative dot in the image is used as the landing ink droplet amount in consideration of the case where different landing ink droplet amounts are mixed in the image. Therefore, the control load can be reduced even for a complicated image.

The ink viscosity-penetration rate correlation data storage unit 104 stores data showing the correlation between the ink viscosity and the penetration rate for each recording medium type and ink type, as shown in FIG. Further, the electric field strength and ink viscosity correlation data storage unit 106 stores data showing the correlation between the electric field strength and the ink viscosity for each ink type as shown in FIG. Although the graph in FIG. 9 is a straight line, it may be a curved line depending on the type of electrorheological fluid.

The electric field strength calculation unit 108 calculates the electrolytic strength required to realize the permissible permeation rate using these data. That is, the permissible viscosity νo corresponding to the permissible permeation velocity Vo is calculated by applying the viscosity-permeation rate correlation data shown in FIG. 8 based on the permissible permeation velocity Vo just calculated. Further, the electric field strength-viscosity correlation data of FIG. 9 is applied to this allowable viscosity to calculate the corresponding predetermined electric field strength Eo.

The electric field strength control means 68 outputs an electric field control signal 110 for driving the electrode 66, which is the electric field applying means, to the electrode 66 with the predetermined electric field strength Eo (or Eo or more) calculated in this way.

The electric field strength control means 68 calculates a predetermined electric field strength corresponding to the permissible penetration speed as described above, and as a result, a graph showing the relationship between the penetration speed and the electric field strength as shown in FIG. 10 shows the ink type. Obtained for each recording medium type. Therefore, if the correlation data between the penetration rate and the electric field strength as shown in FIG. 10 is stored in advance for each combination of the ink type and the recording medium type, the calculation becomes easier.

Next, when the recording medium type is a permeation-fixing medium, the ink is quickly permeated in a low-viscosity state, and the droplet control means 74 is used to prevent landing interference between adjacent dots during image recording. Drop timing control will be described with reference to FIGS. 10 to 15.

In the inkjet recording apparatus 10, when the dots formed on the recording paper 16 which is the penetration fixing type medium overlap, the ink droplet 120 which has been dropped first drops the ink droplet 120 which has been dropped first before the penetration into the recording paper 16 is completed. The timing of dropping (recording) is controlled so as to drop the ink droplet 130 (shown in FIG. 13).

FIG. 11 shows the ink droplet 120 that was previously dropped. The droplet diameter on the surface of the recording paper 16 of the ink droplet 120 is D1a. When the dye-based ink is used, the ink droplet 120 that has landed on the surface of the recording paper 16 permeates into the image receiving layer (not shown) of the recording paper 16 with the passage of time, and the permeation penetrates from the outside to the inside of the ink droplet 120. As it completes toward the center, the diameter of the ink droplet gradually decreases toward the center.

After the lapse of a predetermined time T, the solvent on the surface of the recording paper 16 disappears, and the ink droplet 120 completely penetrates into the recording paper 16. Here, dots having a predetermined size (in the present embodiment, the same diameter as the ink droplet diameter at the time of impact) are formed. This time T is defined as the complete penetration time.

FIG. 12 is a cross-sectional view taken along the line XII-XII in FIG. 11, showing the state immediately after the ink droplet 120 has landed on the recording paper 16. FIG. 13 shows a state in which the diameter of the ink droplet 120 on the surface of the recording paper 16 becomes D1b after a predetermined time less than the complete penetration time T elapses after the ink droplet 120 lands on the recording paper 16. ..

The circle shown by the broken line in FIG. 13 indicates the dot 122 formed by the ink droplet 120, and the size thereof is substantially the same as the size of the ink droplet when the ink droplet 120 lands on the recording paper 16. That is, the ink droplet 120 forms a dot 122 having a diameter of D1a.

Further, FIG. 13 shows a state in which an ink droplet 130 having a diameter D2a is dropped to form a dot 132 having a dot diameter D2a at a distance (dot pitch) Pt between the dot centers and the dot 122.

The diameter D1b after the time δT has elapsed since the ink droplet 120 that was previously dropped landed on the recording paper 16, the diameter D2a of the ink droplet 130 when it landed on the recording paper 16, the ink droplet 120 and the ink. Spacing from the drop 130 (corresponding to the dot pitch, which is the distance between the ink droplet 120 and the center of the dot formed by the ink droplet 130.) The relationship of Pt is as follows (2) D1b &lt;2 × Pt --D2a ... When the condition (2) is satisfied, the ink droplet 120 and the ink droplet 130 are not mixed on the surface of the recording paper 16, so that the dots 122 and 132 formed from the ink droplet 120 and the ink droplet 130 ( In FIG. 13, the shape of the ink droplet 130 (formed at the same size and the same position as the ink droplet 130) does not collapse. Therefore, a desired dot shape can be obtained.

Here, the condition that the dot 122 and the dot 132 overlap is expressed by the equation Pt &lt;(D1a / 2) + (D2a / 2). In other words, the condition that the dot 122 and the dot 132 overlap is that the sum of the radius of the dot 122 and the radius of the dot 132 is larger than the dot pitch Pt.

In the dots 122 shown in FIG. 13, the area where the ink droplet 120 has not penetrated into the recording paper 16 (the area shown as the ink droplet 120) and the area where the ink droplet 120 has penetrated into the recording paper 16 are completed and recorded. There is a region in which the ink dye (solute) is retained inside the image receiving layer of the paper 16 (a region obtained by removing the region indicated as the ink droplet 120 from the region of the dot 122 indicated by the broken line) and the above-mentioned 2 Of the one region, the other ink droplets 130 can be landed on the region where the ink droplets 120 have completely penetrated into the recording paper 16.

FIG. 14 is a cross-sectional view (corresponding to FIG. 12) showing a cross section of the ink droplet 120 and the ink droplet 130 along the XIV-XIV line in FIG. When the ink droplets 130 permeate the recording paper 16, in the portion where the dots 122 and the ink droplets 130 overlap, even if the ink droplets 120 and the ink droplets 130 are mixed in the image receiving layer of the recording paper 16, the ink droplets 130 are mixed. Since 120 has already penetrated into the image receiving layer and the ink dye (solute) is retained in the image receiving layer, the shape of the dots 122 inside the image receiving layer hardly changes.

When the above-mentioned complete penetration time T elapses after the ink droplet 130 lands on the recording paper 16, the penetration of the ink droplet 130 into the recording paper 16 is completed, and as shown in FIG. 14, the dots 122 having a diameter D1a and the diameter Dot 132 of D2a is formed.

FIG. 16 is a cross-sectional view showing a cross section of dots 122 and 132 along the XVI-XVI line in FIG.

In this way, when two dots overlap, the next ink is dropped without waiting for the complete penetration time T (in the state of D1b&gt; 0) at which the penetration of the previously dropped ink drop ends. Can be done.

That is, from the distance Pt between the ink droplet 120 that landed first and the ink droplet 130 that landed next, the diameter D2a at the time of impact of the ink droplet 130, and the ink droplet 120 that satisfies the above equation (2) when the ink droplet 130 lands. The diameter D1b is obtained, and the penetration time δT is obtained from the obtained diameter D1b of the ink droplet 120 and the diameter D1a at the time of impact of the ink droplet 120. The drip timing of the ink droplet 120 and the ink droplet 130 is controlled by using the permeation time δT thus obtained as the drip interval.

In the case of ink, which has a large molecular structure of the ink dye and is mixed in the solvent without being dissolved in the solvent (most pigments are of this type), when the ink droplets land on the surface of the recording paper 16, the solvent penetrates into the image receiving layer. However, although some of the dyes penetrate into the image receiving layer, most of the dyes solidify on the surface of the paper. As described above, it is possible to apply the above-mentioned droplet timing control to the pigment-based ink in which most of the ink dyes solidify on the surface of the recording paper 16.

At that time, the penetration of the solvent is completed from the outside to the inside. Therefore, in order to prevent the ink droplets from being mixed on the surface of the recording paper 16, the droplet control method as described above can be preferably used.

FIG. 17 is a block diagram showing details of the droplet control means 74 for executing the droplet control described above. The drip control means 74 is included in the system (print control unit 86) shown in FIG.

When the image data 200 is acquired from the host computer 76 shown in FIG. 5, the dot data generation unit 210 converts RGB data into CMY data, distributes light and shade inks, and generates CMYK dot data.

Next, in the inequality calculation unit 212, the pitch Pt of the two dots (for example, the ink droplet 120 and the ink droplet 130 shown in FIG. 15) and the diameter D2a of the ink droplet (ink droplet 130 in FIG. 15) to be dropped later. Therefore, the diameter D1b of the ink droplet (ink droplet 120 in FIG. 15) that was previously dropped can be obtained.

On the other hand, the information on the time change of the ink droplet size to be used stored in the dot diameter calculation / storage unit 214 is referred to, and in the timing calculation unit 216, when the ink droplet forming the dot to be dropped first is landed. The permeation time δT (droplet interval) from the droplet diameter D1a to the above-mentioned D1b can be obtained. Further, the timing control parameters in the sub-scanning direction (recording paper transport speed, etc.) and the timing control parameters in the main scanning direction are determined from the permeation time δT.

The nozzle drive signal generation unit 218 generates a drive signal 220 for each nozzle based on the permeation time δT thus obtained, the timing control parameter in the sub-scanning direction, and the timing control parameter in the main scanning direction.

Here, the penetration rate of the ink droplets into the recording paper 16 mainly depends on the type of ink, the type of the recording paper 16, the circulation temperature, the humidity, and the like.

The dot diameter calculation / storage unit 214 stores these information in a data table, and provides the timing calculation unit 216 with parameters for obtaining the penetration time δT calculated by the calculation.

The permeation time δT may be obtained by referring to the data of the diameter D1b from the database in which the diameter D1b is calculated and registered in advance from the diameter D1a, the diameter D2a, and the dot spacing Pt. This database may be provided inside the inkjet recording device 10 or may be provided outside.

For example, the ink type information 230 may be read by the ink type detecting means 64 when the ink cartridge is loaded, the ink type information 230 may be stored, and this ink information may be provided to the timing calculation unit 216 when printing is executed. Similarly, when the recording paper 16 is loaded, the medium type detecting means 60 can read the paper type information 232 and store it.

Hereinafter, the operation of the present embodiment will be described with reference to the flowchart of FIG.

First, in step S100 of FIG. 18, at the start of printing, the ink type detecting means 64 detects the ink type, and the medium type detecting means 60 detects the type of the recording paper 16. In the present embodiment, the ink used is the UV curable ink as described above having an electrorheological effect, and the recording paper 16 is a surface-fixing medium or a surface-fixing medium as described above in relation to the ink. It shall be classified as one of the permeation-fixing media.

Next, in step S110, the system controller 80 determines whether the type of recording paper 16 is a surface fixing type medium or a penetration fixing type medium based on the detection result, and performs processing according to the type of recording paper 16. To. This determination method is not particularly limited. For example, a threshold value is set in advance for the ink penetration rate obtained by the combination of the detected recording medium type and the ink type, and when the ink penetration rate is smaller than this threshold value, a surface-fixing medium is used and the ink penetration rate is high. If it is larger than this threshold value, it may be determined that the medium is a permeation-fixing type medium, or it may be preset in advance according to the type of the recording medium.

If it is determined in step S110 that the recording paper 16 is a surface-fixing medium, the process proceeds to step S120 or less, the ink droplets do not penetrate more than a predetermined amount, and the ink droplets reach the surface of the recording paper 16. In order to cure UV in the existing state, a predetermined electric field is applied to the UV-curable ink having an electroviscosity effect to change the viscosity of the ink, and the penetration rate of the ink into the recording paper 16 is controlled. To do.

That is, in step S120, first, the penetration speed calculation unit 102 of the electric field strength control means 68 calculates the desired ink penetration speed as described above. Next, in step S130, the electric field strength calculation unit 108 calculates the optimum viscosity corresponding to the permissible penetration rate using the correlation data of the ink viscosity and the penetration rate correlation data storage unit 104. Next, in step S140, the electric field strength calculation unit 108 calculates a predetermined electric field strength using the correlation data between the electric field strength and the ink viscosity correlation data storage unit 106.

The electric field strength control means 68 generates an electric field control signal 110 corresponding to the calculated predetermined electric field strength, thereby controlling the electrode 66 for applying an electric field to the ink landed on the recording paper 16. That is, in step S150, the electrode 66 generates an electric field in the space between the electrodes 66 by the electric field control signal 110 from the electric field strength control means 68, and the ink droplets landed on the surface of the recording paper 16 conveyed in the electric field 66. Apply an electric field. At this time, at the same time, the irradiation control means 72 controls the UV light source 70 to irradiate the ink droplets with UV light.

Next, in step S160, the printing unit 12 records an image on the recording paper 16 based on the image data, and when the recording paper 16 is conveyed, an electric field is applied to the ink landed on the recording paper 16. The viscosity of the ink increases and the penetration rate of the ink slows down. At the same time, UV light is irradiated and UV curing is performed while the ink is present on the surface of the recording paper 16, so that high-quality image recording without bleeding is realized.

At this time, by applying the minimum necessary electric field to achieve the desired ink penetration rate, it is possible to reduce the influence of the electric field on the ink in the print head, and non-ejection due to thickening of the ink by the electric field. Can be prevented.

On the other hand, when it is determined in step S110 that the recording paper 16 is a permeation fixing type medium, the ink is quickly permeated into the recording paper 16 in a state where the ink viscosity is low without applying an electric field. .. That is, in step S170, the ink viscosity is controlled to a low state by not applying an electric field so that the ink permeates quickly. Then, in step S180, image recording is performed while controlling the dropping timing as described above.

In this case, since the ink penetration speed is high, as described above, even when the dots are formed by overlapping the dots, a relatively short dripping interval is set and the dripping control is performed at the dripping interval as described above to be adjacent to each other. It is possible to prevent landing interference between dots.

Although the image forming apparatus of the present invention has been described in detail above, the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the gist of the present invention. Of course.

<figref num="1">It is an overall block diagram of the inkjet recording apparatus as an image forming apparatus which concerns on one Embodiment of this invention.</figref><figref num="2">It is a plane perspective view which shows the structure of a print head.</figref><figref num="3">It is a cross-sectional view along the line III-III in Fig. 2.</figref><figref num="4">It is a plane perspective view which shows the other structural example of a print head.</figref><figref num="5">It is a block diagram of a main part which shows the system structure of an inkjet recording apparatus.</figref><figref num="6">It is a block diagram which shows the detail of the electric field strength control means.</figref><figref num="7">It is sectional drawing which shows the ink droplet which landed on the recording paper, (a) shows immediately after landing, (b) shows after curing.</figref><figref num="8">It is a diagram which shows the correlation of viscosity and permeation rate.</figref><figref num="9">It is a diagram which shows the correlation of electric field strength and viscosity.</figref><figref num="10">It is a diagram which shows the correlation between a permeation rate and an electric field strength for each combination of an ink type and a recording medium type.</figref><figref num="11">It is a top view of the ink droplet which landed on the recording paper for demonstrating the droplet control of the inkjet recording apparatus in this embodiment.</figref><figref num="12">It is a cross-sectional view along the XII-XII line in FIG.</figref><figref num="13">It is a top view of the ink droplet which shows the main part of the droplet control.</figref><figref num="14">It is sectional drawing along the XIV-XIV line in FIG.</figref><figref num="15">It is a top view of the ink droplet which shows the result of the droplet control.</figref><figref num="16">It is a cross-sectional view along the XVI-XVI line in FIG.</figref><figref num="17">It is a block diagram which shows the outline of the drop-drop control unit in this embodiment.</figref><figref num="18">It is a flowchart which shows the operation of this embodiment.</figref>

Code description

10 ... Inkjet recording device, 12 ... Printing section, 14 ... Ink storage / loading section, 16 ... Recording paper, 18 ... Feeding section, 20 ... Decal processing section, 22. .. Suction belt transport part, 24 ... print detection part, 26 ... paper ejection part, 28 ... cutter, 30 ... heating drum, 31, 32 ... rollers, 33 ... belt, 34 ... suction chamber, 35 ... fan, 36 ... belt cleaning part, 40 ... heating fan, 42 ... post-drying part, 44 ... heating / pressurizing part, 45 ... Pressurized roller, 48 ... cutter, 50 ... print head, 51 ... nozzle, 52 ... pressure chamber, 53 ... ink supply port, 54 ... pressure chamber unit, 55 ... Ink common flow path, 56 ... vibrating plate, 58 ... actuator, 60 ... medium type detecting means, 62 ... transfer control means, 64 ... ink type detecting means, 66 ... electrodes, 68 ... Electric field strength control means, 70 ... UV light source, 72 ... Irradiation control means, 74 ... Drip control means, 80 ... System controller, 102 ... Penetration speed calculation unit, 104 ... Ink viscosity and penetration rate correlation data storage unit, 106 ... Electric field strength and ink viscosity correlation data storage unit, 108 ... Electric field strength calculation unit