Device for printing one or several objects moving in a feed direction

The invention relates to a device for printing one or more objects movable in a feed direction, in particular labels, packagings, packaging sections, a strip strip or labels adhering to a carrier tape strip, comprising a thermal print head and means for feeding the object to be printed to the thermal print head It is defined in detail in the preamble of claim 1,

Such a device is, for example, shown in FIG <patcit id="pcit0001" dnum="US6431773B1"><text>US 6431773 B1</text></patcit> known. In the device according to FIG<patcit id="pcit0002" dnum="DE19507892A1"><text>DE 195 07 892 A1</text></patcit> A label tape consisting of a carrier tape strip with labels releasably adhered thereto is passed between a thermal print head and a printing drum and printed by a thermal or thermal transfer method. The labels are subsequently detached from the carrier tape by means of a separating device, the latter being guided around a dispensing edge. The print head is fixed in the apparatus in a stationary manner and remains on the label or the carrier strip strip during printing during the entire transport and printing time.

Furthermore, devices are known according to the invention in which the print head is lifted off the label and the carrier tape strip for the times during which it is not printed.

The printing speed of a thermal printer is limited in print quality. Furthermore, the wear of the thermal bar increases as the speed increases.

The <patcit id="pcit0003" dnum="US6431773B1"><text>US 6,431,773 B1</text></patcit> Discloses a device for printing an object which can be moved in a direction of advance, having a print head and means for feeding the object to the print head. In the described exemplary embodiments, the device is designed as a plotter which has a. Printhead. As a possible embodiment of the print head, a thermal print head is also mentioned in this document. The apparatus comprises a frame defining a work support surface and means for continuously transporting web-shaped work material to be printed in a first coordinate direction extending in its longitudinal direction across the work support surface. An elongated beam having first and second ends is coupled to the frame and extends across the work supporting surface. The printhead is coupled to the carrier such that it is movable between its first and second ends. A controller in which graphical data is stored provides commands to the device to control the positional relationship of the printhead relative to the carrier and the work material. In operation, the combined movement of the print head and work material according to the commands issued by the controller causes the print head to print successive linear portions of a graphic that is nearly perpendicular to the first coordinate direction.

It is an object of the present invention to improve a device of the type mentioned at the outset in that it provides a higher printing performance or labeling performance without reducing the print quality and / or increasing the thermolist wear.

This object is achieved by a device having the features of claim 1. The thermal print head of the device according to the invention is provided with a drive by which the thermal print head can be moved parallel to the feed direction of the object to be printed in its feed direction and counter to its feed direction. The drive is associated with a controller which controls it such that the thermal head has the same speed as the moving object or a slower speed than the moving object when moving parallel to the direction of advance of the object. Furthermore, the device according to the invention is characterized in that the thermal head is moved at a distance from the object or labels adhering thereto when the object is moved counter to the direction of advance of the object.

In this case, means for detecting the feed speed of the object to be printed can preferably be provided, which transmit measuring signals proportional to the feed speed to the control, the control controlling the movement of the print head as a function of the detected feed speed.

A further advantageous embodiment of the device according to the invention is characterized in that the drive, by means of which the print head can be moved in the feed direction, as well as counter to the direction of advance of the object to be printed, has a thrust crank mechanism or a piezoactuator. With a thrust crank mechanism, particularly fast forward and backward thrust movements of the print head parallel to the feed direction of the belt strip can be realized in a reliable manner. The same applies to a piezoelectric actuator.

An advantageous development of the device according to the invention consists in that the stroke length of the thrust crank mechanism is adjustable. This embodiment makes it possible to adapt the forward and backward movement of the print head parallel to the feed direction of the object to be printed, for example as a function of the label length and / or the spacing of labels to be printed on the tape strip.

A preferred embodiment of the device according to the invention furthermore consists in the fact that the print head is mounted on a carrier mounted in a sliding guide which also carries the drive by which the print head can be moved towards the object to be printed and away from the object to be printed. This drive can have a cam disk or a circular disk with an eccentrically arranged axis of rotation, by means of which the print head can be brought into contact with the object to be printed against the action of at least one spring element, preferably a helical spring.

Instead of a printing roller, as is the case with conventional devices having a stationary print head , the device according to the invention can preferably be arranged opposite the print head, preferably a plate-shaped counter bearing, by means of which the rear side of the ribbon strip slides during its advance.

Further preferred and advantageous embodiments of the device according to the invention are given in the subclaims.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is explained in more detail below on the basis of a drawing which illustrates a plurality of exemplary embodiments. Show it:<dl id="dl0001"><dt>FIG</dt><dd>10 is a schematic, non-dimensional representation of a device according to the invention according to a first exemplary embodiment, and FIG</dd><dt>FIG</dt><dd>2 shows a schematic, non-dimensional representation of a device according to the invention in accordance with a second exemplary embodiment.</dd></dl>

1 shows a device for printing labels 2 adhering to a carrier tape strip 1. The labels 2 are mounted on the strip strip 1 with a substantially uniform spacing from one another. The strip strip 1 is unwound from a supply roller 3 and fed to a printing unit. The printing unit consists of a printing head 4 in the form of a thermal print head and a plate-shaped counter bearing 5 having a smooth surface, over which the rear side of the strip strip 1 slides as it is fed. The print head 4 has a strip-shaped design and extends transversely to the feed direction of the strip strip 1 substantially over its width or the width of the labels. The print head 4 presses the labels 2 with a sufficient force against the fixed plate-shaped counter bearing 5 and prints them, for example, by thermal or thermal transfer. A relatively sharp deflection in the form of a dispensing edge 6 is provided downstream of the printing unit in the direction of travel of the tape in the form of a dispensing edge 6 at which the printed labels 2 can be detached from the carrier tape strip 1 in a manner known per se and taken through an opening in the housing of the device and applied to an object to be designated . After the deflection, the carrier strip strip 1 is wound on the dispensing edge 6 on a winding-up reel 8 of a winding-up device, which is driven by a stepping motor 7. The rotational speed of the stepping motor 7 or of the winding roller 8 is preferably steplessly adjustable.

The thermal print head 4 is held on a plate-shaped carrier 9, which is mounted in a sliding guide 10. The schematically illustrated sliding guide 10 can, for example, also be formed from roller bearings. The carrier 9 is provided with a drive by means of which it and thus the printing head 4 can be moved parallel in the feed direction and counter to the feed direction of the strip strip 1. This is indicated by the double arrow. In the exemplary embodiment shown, the drive comprises a stationary motor 11, preferably an electric motor whose motor shaft 12 drives a circular disc 13. The circular disc 13 has an eccentrically arranged pin 14, on which the one end of an articulated rod 15 is pivoted. The other end of the connecting rod 15 is braced with a pin 16 attached to the carrier 9. The circular disc 13 with the eccentrically arranged pin 14, the articulated rod 15 pivoted thereon and the carrier 9 mounted in a sliding guide with the articulated pin 16 attached thereto thus form a thrust crank mechanism. The distance between the rotational axis of the motor shaft 12 and the center point of the articulation pin 14 attached to the circular disc 13 determines the stroke length of the thrust crank mechanism.

In order to be able to displace the print head 4 with different stroke lengths in the feed direction as well as in the direction opposite to the feed direction of the carrier strip strip 1, the distance of the articulation pin 14 with respect to the axis of rotation of the motor shaft 12 is adjustable and the articulation pin 14 can be displaced and fixed in a fixed manner on the circular disk 13 .

A controller 17 is associated with the motor 11 of the drive, which controls the drive in such a way that the print head 4 has the same speed as the carrier strip strip 1 or a slower speed than the carrier strip strip 1 during movement in the feed direction of the carrier strip strip 1. Reference numerals 18 and 19 denote a light-emitting transmitter diode and a light-responsive receiving diode, which are part of a measuring device for detecting the feed speed of the carrier strip strip 1. The substantially uniformly spaced apart labels 2 or other uniformly spaced markings on the carrier strip strip 1 interrupt the reception of the light emitted by the transmitter diode 18 at the receiving diode 19 when the strip strip is made transparent. If, in contrast to the illustration in the drawing, the receiving diode is to receive the light emitted by the transmitter diode on the labels 2 or on the label-free sections 20 of the carrier tape strip 1, Side of the carrier strip strip 1. As an alternative to the transmitter and receiver diodes 18, 19, other means can also be used to detect the feed speed of the carrier strip, for example a dynamo or the like rolling on the carrier strip strip. It is arranged on the side of the carrier strip strip 1 facing the label 2, in contrast to the illustration in the drawing, together with the transmitter diode 18. As an alternative to the transmitter and receiver diodes 18, 19, other means can also be used to detect the feed speed of the carrier strip, for example a dynamo or the like rolling on the carrier strip strip. It is arranged on the side of the carrier strip strip 1 facing the label 2, in contrast to the illustration in the drawing, together with the transmitter diode 18. As an alternative to the transmitter and receiver diodes 18, 19, other means can also be used to detect the feed speed of the carrier strip, for example a dynamo or the like rolling on the carrier strip strip.

The receiving diode 19 or the dynamo supplies measuring signals, which are proportional to the feed speed of the carrier strip strip 1. These signals are passed to the measuring and control device 17, which controls the rotational speed of the motor shaft 12 and thus the translational movement of the carrier 9 and the printing head 4 as a function of the detected feed speed of the carrier strip strip 1.

The carrier 9 is provided with a device by means of which the print head 4 can be moved towards the carrier strip strip 1 and away from the carrier strip strip 1. This device is also connected to the measuring and control device 17 via a signal line 21 and comprises an electric motor 26, preferably a stepping motor, and a circular disc 27 with an eccentrically arranged axis of rotation. Denoted at 28 is a mount for the motor 26 formed on the carrier 9. The carrier 9 is shown in longitudinal section in the drawing. The printing head 4 is provided with rods 29, 30 which extend parallel to one another and which are guided in slide bearings formed in the carrier 9. The upper ends of the rods 29, 30 are connected to one another by a transverse rod 31. A spring element 32 in the form of a coil spring is arranged between the carrier and the transverse rod and moves the print head 4 away from the strip strip. By means of the eccentrically mounted circular disk 27, which engages on the upper side of the transverse rod 31, the print head 4 can be brought into contact with the carrier strip stiffener 1 or the label 2 to be printed in each case against the action of the helical spring 32.

The measuring and control device 17 controls the drives in such a way that the print head 4 rests on a label 2 to be imprinted on the carrier tape strip when it moves in the direction of advance of the carrier tape strip 1 and moves away from the carrier tape strip in the direction opposite to the feed direction of the tape strip 1 Or the labels 2 adhered thereto.

The embodiment shown in FIG. 2 differs from the embodiment shown in FIG. 1 only in that, instead of the electric motor 26, the eccentrically mounted circular disc 27, the holder 28, the parallel guide formed from the rods 29, 30 and the transverse rod 31, Spring element 32, at least one piezoelectric actuator 33 is used to raise and lower the print head 4. The thermal print head 4 is fastened in FIG. 2 to at least one piezoactuator 33, which in turn is held on the underside of the plate-shaped carrier 9. The carrier 9 is again mounted in a sliding guide 10. Instead of a sliding guide 10, however, a roller bearing can also be used, as already mentioned.

The invention is not limited to the embodiments described above. Rather, several variants are conceivable within the scope of the inventive idea as defined in the claims. In particular, the invention is not limited to the printing of labels adhering to a carrier tape strip. Likewise, the invention can also be used for the printing of single-sided adhesive-coated continuous paper (so-called linerless), individually fed labels without backing paper, as well as partial package covers made of paper or cardboard.

Reference list

<dl id="dl0002" compact="compact"><dt>1</dt><dd>Carrier strip strips</dd><dt>2</dt><dd>label</dd><dt>3</dt><dd>Storage roll</dd><dt>4</dt><dd>Print head (thermal print head)</dd><dt>5</dt><dd>Counter bearings</dd><dt>6</dt><dd>Dispensing edge</dd><dt>7</dt><dd>Step motor</dd><dt>8th</dt><dd>Winding roller</dd><dt>9</dt><dd>carrier</dd><dt>10</dt><dd>Sliding guide</dd><dt>11</dt><dd>engine</dd><dt>12</dt><dd>Motor shaft</dd><dt>13</dt><dd>Circular disc</dd><dt>14</dt><dd>Joint pins</dd><dt>15</dt><dd>Articulated rod</dd><dt>16</dt><dd>Joint pins</dd><dt>17</dt><dd>Control (measuring and control unit)</dd><dt>18</dt><dd>Transmitter diode</dd><dt>19</dt><dd>Receiving diode</dd><dt>20</dt><dd>Label-free tape section</dd><dt>21</dt><dd>Signal line</dd><dt>22</dt><dd>Signal line</dd><dt>23</dt><dd>Signal line</dd><dt>24</dt><dd>Signal line</dd><dt>25</dt><dd>Signal line</dd><dt>26</dt><dd>Electric motor</dd><dt>27</dt><dd>Circular disc</dd><dt>28</dt><dd>holder</dd><dt>29</dt><dd>pole</dd><dt>30</dt><dd>pole</dd><dt>31</dt><dd>Crossbar</dd><dt>32</dt><dd>Spring element (coil spring)</dd></dl>