JP2017087430A - Printing device and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing device and a printing method which can suppress a deviation in a landing position due to a temperature environment inside and outside the device and perform high quality printing.SOLUTION: A printing device 1 includes: a conveyance part 12 which conveys a recording medium; a printing part 13 which performs printing on a recording medium conveyed by the conveyance part 12; and a movement part 14 which reciprocally moves the printing part 13 in a direction intersecting the conveyance direction of the recording medium during printing. The printing part 13 includes: a plurality of heads which discharge ink; and temperature detection means 6 which detects the temperature in the heads. The printing device also includes adjustment means which adjusts timing of discharge of ink from the heads in movement of the printing part 13 in the forward path and return path on the basis of the data on the deviation in the landing position of ink due to the temperature in the head measured in advance and the temperature in the heads detected by the temperature detection means 6.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a printing apparatus and a printing method.

  2. Description of the Related Art Printing apparatuses that perform printing on a sheet-like recording medium by an inkjet method are known. This printing apparatus includes a plurality of heads that eject ink, conveys the recording medium, and ejects ink while reciprocating the head in a direction (main scanning direction) perpendicular to the recording medium conveyance direction (sub-scanning direction). It is configured to

  In general, the position at which the head ejects ink and the position at which the ink actually lands on the medium are determined by the speed component in the vertical direction of the ink droplet and the velocity in the scanning direction of the ink jet head in the space between the ink jet head and the medium. It differs because it flies with the composite vector of the components. For this reason, in consideration of this positional deviation, by correcting the ejection timing in the forward printing and the ejection timing in the backward printing, the ink droplets land at the same position in both the forward printing and the backward printing.

  On the other hand, when the environmental temperature around the printing apparatus changes, the temperature of the ink itself also changes. In general, the higher the ink temperature, the lower the viscosity and the more ink weight per drop. For this reason, the head drive waveform is changed according to the head temperature so that the ink discharge amount becomes constant regardless of the head temperature.

  Normally, the printing device for consumers uses the smallest possible distance (platen gap) between the inkjet head and the recording medium in order to ensure landing accuracy, so the effect of changes in the ink flight speed due to changes in the head drive waveform can be ignored. It was a thing. However, in a printing apparatus for industrial use, the platen gap may have to be increased depending on the shape of the recording medium. In this case, since the influence of the change in the ink flight speed cannot be ignored, even if the landing positions of the forward path and the return path are matched at a certain temperature, it may be shifted at other temperatures.

In order to solve such a problem, an attempt has been made to adjust the discharge timing of the forward path or the backward path based on the environmental temperature (see, for example, Patent Documents 1 to 4).
However, in the printing apparatuses of Patent Documents 1 to 4, correction is performed so that the landing positions in the forward path and the backward path are matched, and an absolute landing position shift with respect to the recording medium is not corrected. In particular, in the case of a textile application that requires continuous printing with no print breaks, a deviation in absolute position before and after correction is noticeable.

JP 2005-138323 A JP 2001-96733 A Japanese Patent Laid-Open No. 11-77991 JP 2011-156675 A

  An object of the present invention is to provide a printing apparatus and a printing method that can suppress landing position shift due to temperature environment inside and outside the apparatus and perform high-quality printing.

Such an object is achieved by the present invention described below.
The printing apparatus of the present invention includes a transport unit that transports a recording medium,
A printing unit that performs printing on the recording medium conveyed by the conveyance unit;
A moving unit that reciprocates the printing unit in a direction that intersects the conveyance direction of the recording medium during the printing,
The printing unit includes a plurality of heads that eject ink, and a temperature detection unit that detects a temperature in the head,
In the movement of the forward path and the return path of the printing unit based on the data of the deviation of the landing position of the ink due to the temperature in the head measured in advance and the temperature in the head detected by the temperature detection unit, It has an adjustment means for adjusting the timing of ejection of the ink from the head.

  Thereby, the deviation of the landing position due to the temperature environment inside and outside the apparatus can be suppressed, and high-quality printing can be performed.

The printing apparatus of the present invention includes a plurality of the heads that eject the inks of a plurality of colors,
It is preferable to provide a plurality of the data corresponding to the ink of each color.

  As a result, it is possible to more effectively suppress the deviation of the landing position due to the temperature environment inside and outside the apparatus and perform printing with higher image quality.

  In the printing apparatus of the present invention, it is preferable that the distance between the head and the recording medium is 0.5 mm or more and 10 mm or less.

  Even if the distance between the head and the recording medium is within such a range, the deviation of the landing position due to the temperature environment inside and outside the apparatus can be more reliably suppressed.

  In the printing apparatus according to the aspect of the invention, it is preferable that the transport unit includes a belt having adhesiveness with respect to the recording medium.

  Thus, the recording medium can be adhesively fixed when printing on the recording medium, and thus the printing can be performed stably.

In the printing apparatus according to the aspect of the invention, it is preferable that the moving unit is configured to move the printing unit so that the x direction is orthogonal to the y direction.
This facilitates control of the ink ejection timing for the recording medium.

  The printing method of the present invention is characterized in that printing is performed on a recording medium using the printing apparatus of the present invention.

  Thereby, the deviation of the landing position due to the temperature environment inside and outside the apparatus can be suppressed, and high-quality printing can be performed.

It is a side view which shows suitable embodiment of the printing apparatus of this invention. It is a block diagram of the principal part of the printing apparatus shown in FIG. It is a graph which shows an example of the relationship between the deviation | shift of the landing position of a return path | route with respect to the landing position of an outward path | route, and head temperature.

  Hereinafter, a printing apparatus and a printing method according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

  FIG. 1 is a side view showing a preferred embodiment of the printing apparatus of the present invention. FIG. 2 is a block diagram of a main part of the printing apparatus shown in FIG. FIG. 3 is a graph showing an example of the relationship between the head landing temperature and the deviation of the return landing position relative to the forward landing position. In the following, for convenience of explanation, the depth direction in FIG. 1 is referred to as “x direction”, the left and right direction as “y direction”, and the up and down direction as “z direction”.

  The printing apparatus 1 of the present invention is an apparatus that performs printing on the work W while conveying the work W as a recording medium, and can execute the printing method of the present invention.

  As shown in FIGS. 1 and 2, the printing apparatus 1 includes a machine base 11, a transport unit 12 that transports a work W, a printing unit 13 that applies ink to the work W and performs printing, and a printing unit 13. A moving unit 14 for moving the ink, a drying unit 16 for drying the ink on the workpiece W, an input operation unit 18 for inputting and setting various conditions during printing, and a control unit for controlling the operation of each unit. 15. In the printing apparatus 1, the control unit 15 is electrically connected to the external power supply source 200.

  In the present embodiment, the direction orthogonal to the conveyance direction for conveying the workpiece W (main scanning direction) is the x direction, the direction parallel to the conveyance direction (sub-scanning direction) is the y direction, and the direction orthogonal to the x direction and the y direction. z-direction.

  The transport unit 12 is disposed on the feeding device 3 that feeds out the long workpiece W wound in a roll shape, the winding device 4 that winds up the printed workpiece W, and the machine base 11. And a support device 5 that supports the workpiece W.

  The feeding device 3 is disposed upstream of the machine base 11 in the feed direction (y-axis direction) of the workpiece W. The feeding device 3 includes a feeding roller (feeding reel) 31 that feeds the workpiece W in a roll shape, and a tensioner 32 that tensions the workpiece W between the feeding roller 31 and the support device 5. And have. The feed roller 31 is connected to a motor (not shown) and can be rotated by the operation of the motor.

  The work W can be made of a thin film having ink absorbability and a thin film having ink non-absorbability. In the case of the former, for example, special paper for inkjet recording such as plain paper, high-quality paper, and glossy paper, and other woven fabrics can be used. In the latter case, for example, a plastic film that is not surface-treated for inkjet printing (that is, an ink absorbing layer is not formed), and a plastic film coated with a plastic on a substrate such as paper or the like Are bonded. The plastic is not particularly limited, and examples thereof include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

  The winding device 4 is disposed on the downstream side in the feed direction (y direction) of the workpiece W from the machine base 11 with respect to the feeding device 3. The winding device 4 includes a winding roller (winding reel) 41 that winds the workpiece W in a roll shape, and tensioners 42, 43, and 44 that apply tension to the workpiece W between the winding roller 41 and the support device 5. have. The winding roller 41 is connected to a motor (not shown), and can be rotated by the operation of the motor. The tensioners 42 to 44 are arranged at intervals in this order in the direction away from the winding roller 41.

  The support device 5 is disposed between the feeding device 3 and the winding device 4. The support device 5 includes a main driving roller 51 and a driven roller 52 that are disposed apart from each other in the y direction, an endless belt (belt) 53 that is stretched between the main driving roller 51 and the driven roller 52, and the main driving roller 51 and the driven roller. Tensioners 54 and 55 for applying tension to the workpiece W with the roller 52 are provided.

  The main driving roller 51 is connected to a motor (not shown) and can be rotated by the operation of the motor. Further, the driven roller 52 is transmitted with the rotational force of the main driving roller 51 via the endless belt 53, and can rotate in conjunction with the main driving roller 51.

  The endless belt 53 is a glue belt in which an adhesive layer having adhesiveness is formed on the front surface thereof. A part of the workpiece W is adhesively fixed to the adhesive layer and conveyed in the y direction. During this conveyance, the workpiece W is stably printed. Further, after printing is performed, the workpiece W is peeled from the endless belt 53.

  Similarly to the main driving roller 51 and the driven roller 52, the tensioners 54 and 55 are also arranged apart from each other in the y direction.

  The tensioner 54 can sandwich the workpiece W with the endless belt 53 between the main driving roller 51 and the tensioner 55 can sandwich the workpiece W with the endless belt 53 between the driven roller 52 and the tensioner 54. As a result, the workpiece W tensioned by the tensioners 54 and 55 is fixed to the endless belt 53 and conveyed while the tension is applied. In such a state, the work W is prevented from wrinkling or the like during conveyance, so that when printing is performed, the printing becomes accurate and high quality.

  The printing unit 13 performs drawing (recording) by printing by ejecting ink (ink droplets) onto the workpiece W conveyed by the conveying unit 12. The printing unit 13 includes a carriage unit 132 having a plurality of inkjet heads (ink ejection heads) 2 and temperature detection means 6 that detects the temperature inside the inkjet head 2.

  The ink contains a dye or pigment as a colorant in water as a solvent, and in this embodiment, four colors of black (K), cyan (C), magenta (M), and yellow (Y) are used. Is used.

  In the printing apparatus 1, the workpiece W fed out by the feeding device 3 is intermittently fed (sub-scanned) in the y direction in a fixed state in which the work W is adhesively fixed by the endless belt 53, and the carriage unit 132 is moved relative to the fixed workpiece W. Ink is ejected from the inkjet head 2 while reciprocating (main scanning) in the x direction by 14. This can be performed until printing is completed and an image is formed on the workpiece W. The obtained image may be obtained by multicolor printing (color printing) or may be obtained by single color printing.

  The moving unit 14 supports the printing unit 13 so as to be movable along the x direction during printing. Thereby, the printing unit 13 can reciprocate so as to straddle the work W, and ink can be applied onto the work W during that time. In addition, as a structure of the moving part 14, it is preferable to have a ball screw and a linear guide, for example.

  In addition, it is preferable that the distance of the inkjet head 2 and the workpiece | work W is 0.5 mm or more and 10 mm or less.

  The drying unit 16 is downstream of the printing unit 13 in the conveyance direction of the workpiece W and is disposed between the support device 5 and the winding roller 41 of the winding device 4. The drying unit 16 has a chamber 161 in which a heater is built. Thereby, when the workpiece | work W passes the inside of the chamber 161, the undried ink on the said workpiece | work W can be dried with the heat of a heater.

  A tensioner 42 and a tensioner 43 are arranged on both sides in the y direction via the drying unit 16. As a result, the workpiece W can pass through the chamber 161 in a tensioned state. In such a state, the workpiece W is prevented from wrinkling, for example, during passage, and thus the ink W can be reliably dried.

  The input operation unit 18 is composed of, for example, a touch panel. An operator who is an operator of the printing apparatus 1 can input various conditions during printing via the input operation unit 18. Various conditions are not particularly limited, and examples thereof include a printing program, a conveyance speed and a thickness of the workpiece W. The input operation unit 18 also serves as a display unit that displays information on the printing apparatus 1.

The control unit 15 is electrically connected to the transport unit 12, the printing unit 13, the moving unit 14, the drying unit 16, and the input operation unit 18, and has a function of controlling these operations. As shown in FIG. 2, the control unit 15 includes a CPU (Central Processing Unit) 151 and a storage unit 152.
The CPU 151 executes programs for various processes such as a printing process.

  The storage unit 152 includes, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory) which is a kind of nonvolatile semiconductor memory, and can store various programs.

  For example, an external power supply source 200 that applies a voltage of 200 V, for example, is electrically connected to the control unit 15. Thereby, power is supplied to each unit of the printing apparatus 1.

  The storage unit 152 of the printing apparatus 1 described above has an adjustment program (adjustment unit) that adjusts the timing of ink ejection from the inkjet head 2 to the workpiece W when the printing unit 13 moves in the forward path and in the backward path. Is remembered.

  Further, the storage unit 152 stores data X of the landing position deviation of the ink due to the temperature in the inkjet head 2 measured in advance.

  Then, the CPU 151 executes an adjustment program based on the data X and the temperature in the inkjet head 2 detected by the temperature detection means 6, and the inkjet head in the forward movement and the backward movement of the printing unit 13. 2 is adjusted.

  FIG. 3 is a graph showing the relationship between the temperature in the inkjet head 2 and the deviation of the landing position of the return path from the landing position of the forward path. As can be seen from the graph, the landing positions in the forward path and the return path have a linear correlation with the temperature in the inkjet head 2.

  Based on such a correlation, data on the deviation of the ink landing position in the forward path and the backward path due to the temperature in the inkjet head 2 is created and stored in the storage unit 152.

  Note that the slope of the linear correlation varies depending on the color and type of ink. For this reason, the data X is preferably created for each color ink and stored in the storage unit 152.

The adjustment of the discharge timing can be performed as follows, for example.
When the head temperature is T ₀ , the forward path correction value (correction value of the deviation in the forward path) and the return path correction value (correction value of the deviation in the backward path) of each color ink are obtained in advance, and each of these values are represented by ui ₀ and bi ₀ And ui ₀ and bi ₀ are values that are integral multiples of 1/2400 inch, which is the minimum resolution.

When printing is performed by applying these correction values when the head temperature is T _0, the ejection timing is changed, and the landing positions of the forward pass printing and the backward pass printing match.

When the deviation amount of the landing position of the return path with respect to the forward path per 1 ° C. of the temperature in the inkjet head 2 measured and evaluated in advance is di [mm], the forward correction value of the ink when the head temperature is T The ui and the return path correction value bi are respectively
ui = ui ₀ + round {(T−T ₀ ) * di / 25.4 * 2400/2} (integer)
bi = bi ₀ -round {(T−T ₀ ) * di / 25.4 * 2400/2} (integer)
It becomes.

  The temperature data acquired from the temperature sensor of each inkjet head 2 is applied to the above calculation formula, ui and bi are obtained for each movement of the return path and the forward path, and printing is performed by applying these to the ink of each color.

  By doing so, there is no deviation of the absolute position with respect to the workpiece W regardless of the temperature change of the inkjet head 2, and the landing positions of the forward printing and the backward printing always coincide.

  Note that di can also be obtained from the change in the flying speed of the ink due to the temperature of the inkjet head 2 and the moving speed of the printing unit 13.

  As mentioned above, although the printing apparatus and printing method of this invention were demonstrated about embodiment of illustration, this invention is not limited to this, Each part which comprises a printing apparatus is arbitrary which can exhibit the same function. It can be replaced with that of the configuration. Moreover, arbitrary components may be added.

  In the above-described embodiment, the printing apparatus using four colors of black (K), cyan (C), magenta (M), and yellow (Y) has been described. There may be five colors or more.

  In addition, the printing apparatus and the printing method of the present invention may be a combination of any two or more configurations (features) of the above embodiments.

  DESCRIPTION OF SYMBOLS 1 ... Printing device, 2 ... Inkjet head (ink discharge head), 3 ... Feeding device, 31 ... Feeding roller (feeding reel), 32 ... Tensioner, 4 ... Winding device, 41 ... Winding roller (winding reel) 42 ... tensioner, 43 ... tensioner, 44 ... tensioner, 5 ... support device, 51 ... main driving roller, 52 ... driven roller, 53 ... endless belt (belt), 54 ... tensioner, 55 ... tensioner, 6 ... temperature detection means, DESCRIPTION OF SYMBOLS 11 ... Machine stand, 12 ... Conveyance part, 13 ... Printing part, 132 ... Carriage unit, 14 ... Moving part, 15 ... Control part, 151 ... CPU, 152 ... Memory | storage part, 16 ... Drying part, 161 ... Chamber, 18 ... Input operation unit, 200 ... external power supply source, W ... work, X ... data

Claims (6)

A transport unit for transporting the recording medium;
A printing unit that performs printing on the recording medium conveyed by the conveyance unit;
A moving unit that reciprocates the printing unit in a direction that intersects the conveyance direction of the recording medium during the printing,
The printing unit includes a plurality of heads that eject ink, and a temperature detection unit that detects a temperature in the head,
In the movement of the forward path and the return path of the printing unit based on the data of the deviation of the landing position of the ink due to the temperature in the head measured in advance and the temperature in the head detected by the temperature detection unit, A printing apparatus comprising: an adjusting unit that adjusts a timing of discharging the ink from the head. Comprising a plurality of the heads for ejecting a plurality of colors of ink;
The printing apparatus according to claim 1, comprising a plurality of the data corresponding to the ink of each color.   The printing apparatus according to claim 1, wherein a distance between the head and the recording medium is 0.5 mm or more and 10 mm or less.   The printing apparatus according to claim 1, wherein the transport unit includes a belt having adhesiveness with respect to the recording medium.   The printing apparatus according to claim 1, wherein the moving unit is configured to move the printing unit so that the x direction is orthogonal to the y direction.   6. A printing method comprising printing on a recording medium using the printing apparatus according to claim 1.

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