JP2017087429A - Printer and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer excellent in improvement of image quality and resolution of an image obtained by bidirectional printing, and a printing method.SOLUTION: A printer 1 comprises a printing section 13 imparting ink droplets onto a recording medium and applying printing thereto. The printing section 13 comprises: first nozzle arrays (for example, a nozzle array 22Kand a nozzle array 22K) having a plurality of first nozzles (for example, nozzles 21K); and second nozzle arrays (for example, a nozzle array 22Cand a nozzle array 22C) having a plurality of second nozzles (for example, nozzles 21C). The first nozzle arrays are provided in a symmetrical manner to each other with respect to a center-line Oof the printing section 13. Each first nozzle of one first nozzle array and each first nozzle of the other first nozzle array are mutually disposed at the same position in a Y direction. The second nozzle arrays are provided in the symmetrical manner to each other with respect to the center-line O. Each second nozzle of one second nozzle array and each second nozzle of the other second nozzle array are mutually disposed at the same position in the Y direction.SELECTED DRAWING: Figure 3

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 (see, for example, Patent Document 1 and Patent Document 2). The printing apparatus includes a head having a large number of nozzles, and transports a recording medium and ejects ink while moving the head in a direction (main scanning direction) orthogonal to the recording medium transport direction (sub-scanning direction). It is configured as follows. Further, the ink ejected from each nozzle will land on the recording medium. Each landing area where the ink has landed constitutes a part of the image on the recording medium, and as a result, a collection of these landing areas is recognized as an image.

  For example, Patent Document 2 discloses an arrangement state of a large number of nozzles included in a head. These nozzles are divided into nozzle rows for each ink color, and a plurality of nozzles belonging to each nozzle row are arranged in one row along the sub-scanning direction. Moreover, each nozzle row is arrange | positioned along the main scanning direction.

  However, in such an arrangement, when the head reciprocates on the recording medium, the order in which the ink colors overlap in the forward path and the backward path is reversed, and there is a hue between the color obtained in the forward path and the color obtained in the backward path. It looks different. As a result, the image on the recording medium is inferior in image quality. Further, since the nozzle row is one row for each color, it has not been possible to sufficiently satisfy the demand for obtaining an image with further improved resolution.

JP-A-6-183013 JP2013-256075A

  An object of the present invention is to provide a printing apparatus and a printing method excellent in improving the image quality and resolution of an image obtained by 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 by applying ink droplets on the recording medium conveyed by the conveyance unit;
A moving unit that moves the printing unit in a direction that intersects the conveyance direction of the recording medium during the printing,
When the moving direction of the printing unit is the X direction and the transport direction of the recording medium is the Y direction,
The printing unit ejects ink droplets of a first color and has a first nozzle row having a plurality of first nozzles arranged along the Y direction;
A plurality of second nozzles arranged in the X direction with respect to the first nozzle row, ejecting ink droplets of a second color different from the first color, and arranged along the Y direction. A second nozzle row having
A pair of the first nozzle rows are provided symmetrically with respect to the center line along the Y direction of the printing unit, and each of the first nozzle rows of the first nozzle row is one of the first nozzle rows. The nozzles and the first nozzles of the other first nozzle row are arranged at the same position in the Y direction,
A pair of the second nozzle rows are provided symmetrically with respect to the center line, and the second nozzle row of one second nozzle row and the second nozzle row of the other of the pair of second nozzle rows. The second nozzles are arranged at the same position in the Y direction.

  Accordingly, the ink ejected from the pair of first nozzle rows can be landed as densely as possible in the X direction on the recording medium, and the ink ejected from the pair of second nozzle rows can also be recorded. It is possible to land as close as possible in the X direction on the medium. Such ink landing contributes to the improvement of the resolution of an image obtained by printing.

  Further, when the printing unit reciprocates on the recording medium in the X direction, the order in which the ink colors overlap can be the same in both the forward path and the backward path. As a result, the color obtained in the forward pass and the color obtained in the return pass look the same, so that the image quality of the image on the recording medium can be improved.

  In the printing apparatus according to the aspect of the invention, the printing unit may individually include the one first nozzle row, the other first nozzle row, the one second nozzle row, and the other second nozzle row. It is preferable that the head is unitized.

  As a result, for example, when one ink ejection head has reached the end of its life, it is possible to continue to use the printing apparatus as long as only that ink ejection head is replaced, and the replacement work is facilitated.

In the printing apparatus according to the aspect of the invention, it is preferable that each of the ink discharge heads includes two nozzle rows included in the ink discharge head, and the two nozzle rows are adjacent to each other in the X direction.
Thereby, the ink that lands on the recording medium can be arranged more densely.

In the printing apparatus according to the aspect of the invention, it is preferable that the two nozzle rows are arranged so as to be shifted in the Y direction.
Thereby, the ink that lands on the recording medium can be arranged more densely.

  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 the control of the ejection timing of the ink droplets on 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.

  Accordingly, the ink ejected from the pair of first nozzle rows can be landed as densely as possible in the X direction on the recording medium, and the ink ejected from the pair of second nozzle rows can also be recorded. It is possible to land as close as possible in the X direction on the medium. Such ink landing contributes to the improvement of the resolution of an image obtained by printing.

  Further, when the printing unit reciprocates on the recording medium in the X direction, the order in which the ink colors overlap can be the same in both the forward path and the backward path. As a result, the color obtained in the forward pass and the color obtained in the return pass look the same, so that the image quality of the image on the recording medium can be improved.

FIG. 1 is a side view showing an embodiment of a 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 diagram illustrating an arrangement state of nozzles of a printing unit included in the printing apparatus illustrated in FIG. 1. FIG. 4 is a diagram sequentially illustrating the landing state of ink on the recording medium when the printing apparatus shown in FIG. 1 is actually used for drawing. FIG. 5 is a diagram illustrating a positional relationship between nozzles that eject ink of the same color. FIG. 6 is a diagram illustrating a positional relationship between nozzles that eject ink of the same color.

  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 an embodiment of a 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 diagram illustrating an arrangement state of nozzles of a printing unit included in the printing apparatus illustrated in FIG. 1. FIG. 4 is a diagram sequentially illustrating the landing state of ink on the recording medium when the printing apparatus shown in FIG. 1 is actually used for drawing. 5 and 6 are diagrams showing the positional relationship between nozzles that eject the same color ink. 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 coordinate axes in FIGS. 3 to 6 correspond to the coordinate axes in FIG.

  The printing apparatus 1 of the present invention is a textile printing apparatus that performs printing on a workpiece W while conveying the workpiece 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 is the x direction, the direction parallel to the conveyance direction is the y direction, and the direction orthogonal to the x direction and the y direction is the 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 work W feeding direction (y direction). 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. As shown in FIG. 3, the printing unit 13 includes a carriage unit 132 having a plurality of inkjet heads (ink ejection heads) 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.

As shown in FIG. 3, the inkjet head 2 is divided into units for each color of ink to be ejected. Thus, for example, when one inkjet head 2 has reached the end of its life, the printing apparatus 1 can be used continuously as long as only the inkjet head 2 is replaced. Moreover, the replacement work of the inkjet head 2 becomes easy by unitization. In the configuration shown in FIG. 3, the inkjet head 2, black (K) ink-jet head 2K ₁ and an ink jet head 2K ₂ for discharging ink, the inkjet heads 2C ₁ and the ink jet head 2C for cyan (C) ink ejection ₂ , an inkjet head 2M ₁ and an inkjet head 2M ₂ for ejecting magenta (M) ink, and an inkjet head 2Y ₁ and an inkjet head 2Y ₂ for ejecting yellow (Y) ink.

  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.

  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 the print process as described above.

  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.

As described above, in the present embodiment, the printing unit 13, a black (K) ink-jet head 2K ₁ and an ink jet head 2K ₂ for discharging ink, the inkjet heads 2C ₁ and the ink jet head 2C for cyan (C) ink ejection ₂ , an inkjet head 2M ₁ and an inkjet head 2M ₂ for ejecting magenta (M) ink, and an inkjet head 2Y ₁ and an inkjet head 2Y ₂ for ejecting yellow (Y) ink.

As shown in FIG. 3, the inkjet head 2K ₁ and the inkjet head 2K ₂ are symmetrical with respect to the center line O ₁₃ along the Y direction of the printing unit 13, that is, the center line O about the center line O _{13. 13} is arranged at a level position in the X direction.

The inkjet head 2C ₁ is disposed on the negative side in the X direction with respect to the inkjet head 2K ₁ , that is, in a direction away from the center line O ₁₃ , and the inkjet head 2C ₂ is on the positive side in the X direction with respect to the inkjet head 2K ₂ . , i.e., they are arranged in a direction away from the center line O _13. Then, the inkjet head 2C ₁ and the ink jet head 2C ₂ are also arranged symmetrically with respect to the centerline _{O 13.}

Inkjet head 2M ₁ is arranged in the X direction negative side with respect to the ink-jet heads 2C _1, the inkjet head 2M ₂ is disposed in the X-direction positive side with respect to the inkjet head 2C _2. Then, the inkjet head 2M ₁ and the ink jet head 2M ₂ are also arranged symmetrically with respect to the centerline _{O 13.}

Inkjet head 2Y ₁ is arranged in the X direction negative side with respect to the inkjet head 2M _1, the inkjet head 2Y ₂ is disposed in the X-direction positive side with respect to the inkjet head 2M _2. Then, the inkjet head 2Y ₁ and the ink jet head 2Y ₂ are also arranged symmetrically with respect to the centerline _{O 13.}

Here, "center line O _13", in a plan view of the workpiece W, i.e., when viewed from the Z direction positive side, the center line O _13, the center line bisecting the workpiece W in the X direction when fitted to the, also becomes symmetrical positional relationship with respect to the center line of the ink jet head 2K ₁ and the ink jet head 2K ₂ and the work W, even the inkjet head 2C ₁ and the ink jet head 2C ₂ and is with respect to the center line of the workpiece W become a symmetrical positional relationship, also becomes symmetrical positional relationship with respect to the center line of the ink jet head 2M ₁ and the ink jet head 2M ₂ and the work W, even the inkjet head 2Y ₁ and the ink jet head 2Y ₂ and is with respect to the center line of the workpiece W It is a line that has a symmetrical positional relationship.

As shown in FIG. 3, the ink jet head 2K ₁ and the ink jet head 2K _2, respectively, have a number of nozzles 21K for discharging black (K) ink droplets. Further, the ink jet head 2C ₁ and the ink jet head 2C _2, respectively, have a number of nozzles 21C for ejecting cyan (C) ink droplets. Further, the inkjet head 2M ₁ and the ink jet head 2M ₂ each have a large number of nozzles 21M for discharging magenta (M) ink droplets. Further, the inkjet head 2Y ₁ and the ink jet head 2Y ₂ each have a large number of nozzles 21Y for discharging yellow (Y) ink droplets. Ink is ejected independently from the nozzles 21K, 21C, 21M, and 21Y.

And arrangement of the nozzles 21K in an ink-jet head 2K _1, the arrangement of the nozzles 21K in an ink-jet head 2K _2, and arrangement of the nozzles 21C in an ink-jet head 2C _1, arrangement of the nozzles 21C in an ink-jet head 2C ₂ When the arrangement of the nozzles 21M in an ink-jet head 2M _1, the arrangement of the nozzles 21M in an ink-jet head 2M _2, and arrangement of the nozzles 21Y in an ink-jet head 2Y _1, the nozzle 21Y in an ink-jet head 2Y ₂ Since the arrangement state is the same, the arrangement state in the inkjet head 2K ₁ will be described as a representative.

In the inkjet head 2K ₁ , a first nozzle row 22K ₁ having a plurality of (six as an example in the present embodiment) nozzles 21K, a plurality of nozzle rows adjacent to the first nozzle row on the X direction positive side, a nozzle array 22K ₂ in the second row having nozzles 21K of (in this embodiment six as an example) is provided.

In the nozzle array 22K _1, 6 single nozzle 21K are arranged along the Y direction at equal pitch (equally spaced). Similarly, in the nozzle array 22K _2, 6 single nozzle 21K are arranged at equal pitches (equidistantly) along the Y direction. Further, the pitch of the nozzles 21K each other in the nozzle array 22K ₁ (center distance), and the pitch of the nozzles 21K each other in the nozzle array 22K ₂ (center distance) is the same. Furthermore, the nozzle array 22K ₁ and nozzle array 22K _2, the nozzle row 22K _1, nozzle array 22K ₂ are arranged offset by a half pitch in the Y direction.

Then, such nozzle array 22K _1, the inkjet head 2K ₁ having a nozzle array 22K _2, the inkjet head 2K ₁ similar nozzle array 22K _1, the ink jet head 2K ₂ having a nozzle array 22K _2, below Have a relationship. For convenience of explanation, the six nozzles 21K belonging to the nozzle row 22K ₁ and the nozzle row 22K ₂ are moved in order from the Y direction positive side to the negative side, that is, from the upper side to the lower side in FIG. , “No. 1 nozzle 21K”, “No. 2 nozzle 21K”, “No. 3 nozzle 21K”, “No. 4 nozzle 21K”, “No. 5 nozzle 21K”, “No. 6 nozzle 21K” .

As shown in FIG. 3, the nozzle array 22K ₁ of the ink jet head 2K _1, and the nozzle array 22K ₁ of the ink jet head 2K _2, X-direction positive side through the center line _{O 13,} disposed on both of the negative side ing. The first nozzles 21K are arranged at the same position in the Y direction, the second nozzles 21K are arranged at the same position in the Y direction, and the third nozzles 21K are arranged at the same position in the Y direction. No. 4 nozzles 21K are arranged in the same position in the Y direction, No. 5 nozzles 21K are arranged in the same position in the Y direction, and No. 6 nozzles 21K are in the same position in the Y direction. Is arranged.

Further, a nozzle array 22K ₂ of the ink jet head 2K _1, even the nozzle array 22K ₂ of the ink-jet heads 2K _2, nozzles 21K between No. 1 is placed in the same position in the Y directions, the nozzles 21K each other No. 2 to each other No. 3 nozzles 21K are arranged at the same position in the Y direction, No. 4 nozzles 21K are arranged at the same position in the Y direction, and No. 5 nozzles 21K are arranged at the same position in the Y direction. The sixth nozzles 21K are arranged at the same position in the Y direction, and the sixth nozzles 21K are arranged at the same position in the Y direction.

Here, the “same position” includes not only the relationship in which the centers O _{21K of the} nozzles 21K are arranged at the same position in the Y direction as shown in FIG. 5, but also the state shown in FIG. In the state shown in FIG. 6, the centers O _{21K of the} nozzles 21K are displaced in the Y direction, but when the two nozzles K are viewed from the positive side in the X direction, there are portions 23 that overlap each other. Such a state is also treated as “the same position”.

In the inkjet head 2C ₁ and the inkjet head 2C ₂ as well, the first nozzle row 22C ₁ and the second nozzle row 22C ₂ have the following relationship. The six nozzles 21C respectively belonging to the nozzle row 22C ₁ and the nozzle row 22C ₂ are arranged in order from the positive side in the Y direction to the negative side, “No. 1 nozzle 21C”, “No. 2 nozzle 21C”, “No. 3”. No. 21C ”,“ No. 4 nozzle 21C ”,“ No. 5 nozzle 21C ”, and“ No. 6 nozzle 21C ”.

A nozzle array 22C ₁ of the ink jet head 2C _1, and the nozzle array 22C ₁ of the ink jet head 2C _2, nozzles 21C together No. 1 is placed in the same position in the Y directions, the nozzle 21C each other No. 2 Y directions Are arranged at the same position, the third nozzle 21C is arranged at the same position in the Y direction, the fourth nozzle 21C is arranged at the same position in the Y direction, and the fifth nozzle 21C is Y from each other. The sixth nozzles 21C are arranged at the same position in the Y direction.

Further, a nozzle row 22C ₂ of the ink-jet heads 2C _1, even with the nozzle row 22C ₂ of the ink-jet heads 2C _2, nozzles 21C together No. 1 is placed in the same position in the Y directions, the nozzles 21C together No. 2 mutually No. 3 nozzles 21C are arranged at the same position in the Y direction, No. 4 nozzles 21C are arranged at the same position in the Y direction, and No. 5 nozzles 21C are arranged at the same position in the Y direction. The sixth nozzles 21C are arranged at the same position in the Y direction, and are arranged at the same position in the Y direction.

Similarly, in the inkjet head 2M ₁ and the ink jet head 2M _2, 1 nozzle row 22M ₁ between two nozzle row 22M ₂ each other, we have the following relationship. The six nozzles 21M respectively belonging to the nozzle row 22M ₁ and the nozzle row 22M ₂ are arranged in order from the Y direction positive side to the negative side, “No. 1 nozzle 21M”, “No. 2 nozzle 21M”, “No. 3”. No. 21M ”,“ No. 4 nozzle 21M ”,“ No. 5 nozzle 21M ”, and“ No. 6 nozzle 21M ”.

A nozzle array 22M ₁ of the ink jet head 2M _1, and the nozzle array 22M ₁ of the ink jet head 2M _2, nozzles 21M between No. 1 is placed in the same position in the Y directions, the nozzles 21M each other No. 2 Y directions The third nozzles 21M are arranged at the same position in the Y direction, the fourth nozzles 21M are arranged at the same position in the Y direction, and the fifth nozzles 21M are mutually Y. The sixth nozzles 21M are arranged at the same position in the Y direction.

Further, a nozzle array 22M ₂ of the ink jet head 2M _1, even with the nozzle row 22M ₂ of the ink jet head 2M _2, nozzles 21M between No. 1 is placed in the same position in the Y directions, the nozzles 21M each other No. 2 to each other No. 3 nozzles 21M are arranged at the same position in the Y direction, No. 4 nozzles 21M are arranged at the same position in the Y direction, and No. 5 nozzles 21M are arranged at the same position in the Y direction. The sixth nozzles 21M are arranged at the same position in the Y direction, and are arranged at the same position in the Y direction.

Further, even in the ink-jet head 2Y ₁ and the ink jet head 2Y _2, 1 nozzle row 22Y ₁ between the nozzle rows 22Y ₂ between the second column has the following relationship. The six nozzles 21Y respectively belonging to the nozzle row 22Y ₁ and the nozzle row 22Y ₂ are arranged in order from the Y side positive side to the negative side, “No. 1 nozzle 21Y”, “No. 2 nozzle 21Y”, “No. 3”. No. 21Y ”,“ No. 4 nozzle 21Y ”,“ No. 5 nozzle 21Y ”, and“ No. 6 nozzle 21Y ”.

A nozzle array 22Y ₁ of the ink jet head 2Y _1, and the nozzle array 22Y ₁ of the ink jet head 2Y _2, the nozzle 21Y together No. 1 is placed in the same position in the Y directions, the nozzle 21Y each other No. 2 Y directions The third nozzles 21Y are arranged at the same position in the Y direction, the fourth nozzles 21Y are arranged at the same position in the Y direction, and the fifth nozzles 21Y are mutually Y. The sixth nozzles 21Y are arranged at the same position in the Y direction.

Further, a nozzle array 22Y ₂ in the ink-jet heads 2Y _1, even the nozzle array 22Y ₂ in the ink-jet heads 2Y _2, the nozzle 21Y together No. 1 is placed in the same position in the Y directions, the nozzle 21Y each other No. 2 to each other No. 3 nozzles 21Y are arranged at the same position in the Y direction, No. 4 nozzles 21Y are arranged at the same position in the Y direction, and No. 5 nozzles 21Y are arranged at the same position in the Y direction. The sixth nozzles 21Y are arranged at the same position in the Y direction, and the sixth nozzles 21Y are arranged at the same position in the Y direction.

By the way, in order to solve the problems in the present invention in the printing apparatus 1, the present inventors
There is a first nozzle row that ejects ink of the first color and has a plurality of first nozzles arranged along the Y direction.
A second nozzle that is arranged in the X direction with respect to the first nozzle row, ejects ink of a second color different from the first color, and has a plurality of second nozzles arranged along the Y direction There are columns.
A pair of first nozzle rows are provided symmetrically with respect to the center line O ₁₃ along the Y direction of the printing unit 13, and each first of the first nozzle rows of the pair of first nozzle rows is provided. The nozzles and the first nozzles of the other first nozzle row are arranged at the same position in the Y direction.
- the second nozzle row are symmetrically provided a pair with respect to the center line O _13, among the pair of second nozzle array, and each of the second nozzles of one of the second nozzle array, while the second nozzle array Are arranged at the same position in the Y direction.
Is defined as a component of the present invention.

In the present embodiment, “the first nozzle row having the first nozzles for the first color ink” is referred to as “the nozzle row 22K ₁ (or the nozzle row 22K ₂ ) having the nozzles 21K for black (K) ink”. In this case, “the second nozzle row having the second nozzle for the ink of the second color different from the first color” is the “nozzle having the nozzle 21C for the cyan (C) ink”. The “row 22C ₁ (or nozzle row 22C ₂ )”, the “nozzle row 22M ₁ (or nozzle row 22M ₂ ) having nozzles 21M for magenta (M) ink”, or the “nozzle row 21Y for yellow (Y) ink” The nozzle row 22Y ₁ (or nozzle row 22Y ₂ ) ”.

In addition, the case where the “first nozzle row having the first nozzle for the first color ink” is set to “nozzle row 22C ₁ (or nozzle row 22C ₂ ) having the nozzle 21C for cyan (C) ink”. The “second nozzle row having second nozzles for ink of a second color different from the first color” includes “nozzle row 22M ₁ (or nozzles) having nozzles 21M for magenta (M) ink”. Column 22M ₂ ) ”or“ nozzle column 22Y ₁ having nozzles 21Y for yellow (Y) ink (or nozzle column 22Y ₂ ) ”.

Further, when “the first nozzle row having the first nozzles for the first color ink” is set to “nozzle row 22M ₁ (or nozzle row 22M ₂ ) having the nozzles 21M for magenta (M) ink”. The “second nozzle row having second nozzles for ink of a second color different from the first color” is changed to “nozzle row 22Y ₁ having nozzles 21Y for yellow (Y) ink (or nozzle row 22Y). ₂ ) ".

Next, how the ink lands on the work W when printing is performed on the work W by the printing apparatus 1 will be described with reference to FIG. Here, a description will be given focusing on ink from the inkjet head 2K ₁ and the inkjet head 2K _{2 as} a representative example.

As shown in FIG. 4, on the work W, first, the ink dot group _D1-1 , the ink dot group _D2-1 , the ink dot group _D3-1, and the ink dots that bear a part of the image. Group _D4-1 is formed. Ink dot group _{D 1-1} is a drawing portion by the first ink from the nozzle array 22K ₁ of the ink jet head 2K _1. Ink dot group _{D 2-1} is a drawing portion by the first ink from the nozzle array 22K ₁ of the ink jet head 2K _2. The ink dot group D _3-1 is a portion drawn with the first ink from the nozzle row 22 </ _b > K ₂ of the inkjet head 2 </ _b > K ₁ . Ink dot group _{D 4-1} is a drawing portion by the first ink from the nozzle array 22K ₂ of the ink jet head 2K _2. The ink dot group _D1-1 and the ink dot group _D2-1 are in a state of being extremely close to each other in the X direction, and the ink dot group _D3-1 and the ink dot group _D4-1 are also X It is very close to the direction.

Next, when ink is discharged for the second time, an ink dot group _D1-2 , an ink dot group _D2-2 , an ink dot group _D3-2, and an ink dot group D are formed on the work W. _4-2 is formed. Ink dot group _{D 1-2} is a drawing portion in the second ink from the nozzle array 22K ₁ of the ink jet head 2K _1. Ink dot group _{D 2-2} is a drawing portion in the second ink from the nozzle array 22K ₁ of the ink jet head 2K _2. Ink dot group _{D 3-2} is a drawing portion in the second ink from the nozzle array 22K ₂ of the ink jet head 2K _1. Ink dot group _{D 4-2} is a drawing portion in the second ink from the nozzle array 22K ₂ of the ink jet head 2K _2. The ink dot group _D1-2 and the ink dot group _D2-2 are in an extremely close state in the X direction, and the ink dot group _D3-2 and the ink dot group _D4-2 are also in the X direction. It is very close to the direction. Furthermore, the ink dot group _D2-1 and the ink dot group _D1-2, and the ink dot group _D4-2 and the ink dot group _D3-2 are also in a state of being extremely close to each other in the X direction.

When the ink is ejected for the third time, the ink dot group D _1-3 , the ink dot group D _2-3 , the ink dot group D _3-3, and the ink dot group D _4-3 are formed on the work W. And are formed. Ink dot group _{D 1-3} is a drawing portion in the third ink from the nozzle array 22K ₁ of the ink jet head 2K _1. Ink dot group _{D 2-3} is a drawing portion in the third ink from the nozzle array 22K ₁ of the ink jet head 2K _2. Ink dot group _{D 3-3} is a drawing portion in the third ink from the nozzle array 22K ₂ of the ink jet head 2K _1. Ink dot group _{D 4-3} is a drawing portion in the third ink from the nozzle array 22K ₂ of the ink jet head 2K _2. The ink dot group _D1-3 and the ink dot group _D2-3 are in a state of being extremely close to each other in the X direction, and the ink dot group _D3-3 and the ink dot group _D4-3 are also X It is very close to the direction. Furthermore, the ink dot group _D2-2 and the ink dot group _D1-3, and the ink dot group _D4-2 and the ink dot group _D3-3 are also in a state of being extremely close to each other in the X direction.

  In the printing apparatus 1, such a state contributes to the higher resolution of the image and is repeated until the image is completed.

For example, if the printing unit 13 and the inkjet head 2K ₂ and the ink jet head 2C ₂ and the ink jet head 2M ₂ and the ink jet head 2Y ₂ is omitted, the image obtained by printing, one-pass printing section 13 (forward or backward) Assume that the resolution of each hit color is 300 dpi in the X direction and 600 dpi in the Y direction.

In contrast, in the printer 1, the printing unit 13, the inkjet head 2K _1, the inkjet head 2K _2, the ink-jet heads 2C _1, the inkjet head 2C _2, the inkjet head 2M _1, the inkjet head 2M _2, the ink-jet heads 2Y _1, inkjet It has become one with all the head 2Y _2. In this case, the resolution of each color in the image can be 600 dpi in the X direction and 600 dpi in the Y direction. Therefore, the printing apparatus 1 is excellent in improving the resolution, and can obtain a high-resolution image.

Further, as described above, it disposed symmetrically with respect to the ink-jet head 2K ₁ and the ink jet head 2K ₂ and the center line _{O 13} are symmetrically arranged with respect to the ink-jet heads 2C ₁ and the ink jet head 2C ₂ and the center line _{O 13} , the inkjet head 2M ₁ and the ink jet head 2M ₂ are symmetrically arranged with respect to the centerline _{O 13,} are symmetrically arranged with respect to the ink-jet heads 2Y ₁ and the ink jet head 2Y ₂ and the center line _{O 13} (see FIG. 3 ). As a result, when the printing unit 13 reciprocates on the workpiece W in the X direction, the order in which the ink colors overlap can be the same in both the forward path and the return path. As a result, the color obtained in the forward path and the color obtained in the backward path look the same, so that the image quality of the image on the workpiece W can be improved.

  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 addition, the transport unit has an endless belt that fixes the workpiece by adhesion in the embodiment, but the present invention is not limited to this. For example, the transport unit may have a platen (stage) that fixes the workpiece by suction. Good.

  In addition, each inkjet head has the first nozzle row and the second nozzle row in the above embodiment, but is not limited to this, and either the first row or the second row. The nozzle row may be omitted.

1 ... printing apparatus, 2 ... inkjet head (ink ejection head), 2K 1 _... inkjet head, 2K 2 _... inkjet head, 21K ... nozzle, 22K 1 _... nozzle array, 22K 2 _... nozzle array, 2C 1 _... inkjet head, 2C ₂ ... inkjet head, 21C ... nozzle, 22C 1 _... nozzle array, 22C 2 _... nozzle array, 2M 1 _... inkjet head, 2M 2 _... inkjet head, 21M ... nozzle, 22M 1 _... nozzle array, 22M 2 _... nozzle array, 2Y ₁ ... inkjet head, 2Y 2 _... inkjet head, 21Y ... nozzle, 22Y 1 _... nozzle array, 22Y 2 _... nozzle array, 23 ... part, 3 ... feeding device, 31 ... delivery roller (supply reel), 32 ... tensioner, 4 ... winding device, 41 ... winding roller (winding Reel), 42 ... Tensioner, 43 ... Tensioner, 44 ... Tensioner, 5 ... Supporting device, 51 ... Main driving roller, 52 ... Follower roller, 53 ... Endless belt (belt), 54 ... Tensioner, 55 ... Tensioner, 11 ... Machine base , 12 ... Conveying unit, 13 ... Printing unit, 132 ... Carriage unit, 14 ... Moving unit, 15 ... Control unit, 151 ... CPU, 152 ... Storage unit, 16 ... Drying unit, 161 ... Chamber, 18 ... Input operation unit, 200 ... External power supply source, _D1-1 ... Ink dot group, _D1-2 ... Ink dot group, _D1-3 ... Ink dot group, _D2-1 ... Ink dot group, _D2-2 ... Ink dot group, _{D 2-3 ...} ink dot group, _{D 3-1 ...} ink dot group, _{D 3-2 ...} ink dot group, _{D 3-3 ...} ink dot group, _{D 4-1 ...} ink dots , _{D 4-2 ...} ink dot group, _{D 4-3 ...} ink dot group, O _{13 ...} center line, _{O 21K ...} center, W ... workpiece

Claims (7)

A transport unit for transporting the recording medium;
A printing unit that performs printing by applying ink droplets on the recording medium conveyed by the conveyance unit;
A moving unit that moves the printing unit in a direction that intersects the conveyance direction of the recording medium during the printing,
When the moving direction of the printing unit is the X direction and the transport direction of the recording medium is the Y direction,
The printing unit ejects ink droplets of a first color and has a first nozzle row having a plurality of first nozzles arranged along the Y direction;
A plurality of second nozzles arranged in the X direction with respect to the first nozzle row, ejecting ink droplets of a second color different from the first color, and arranged along the Y direction. A second nozzle row having
A pair of the first nozzle rows are provided symmetrically with respect to the center line along the Y direction of the printing unit, and each of the first nozzle rows of the first nozzle row is one of the first nozzle rows. The nozzles and the first nozzles of the other first nozzle row are arranged at the same position in the Y direction,
A pair of the second nozzle rows are provided symmetrically with respect to the center line, and the second nozzle row of one second nozzle row and the second nozzle row of the other of the pair of second nozzle rows. The printing apparatus, wherein the second nozzles are arranged at the same position in the Y direction.   The printing unit is unitized as an ink ejection head that individually includes the one first nozzle row, the other first nozzle row, the one second nozzle row, and the other second nozzle row, respectively. The printing apparatus according to claim 1.   The printing apparatus according to claim 2, wherein each of the ink ejection heads includes two nozzle arrays included in the ink ejection head, and the two nozzle arrays are adjacent to each other in the X direction.   The printing apparatus according to claim 3, wherein the two nozzle arrays are arranged to be shifted in the Y direction.   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.   A printing method comprising printing on a recording medium using the printing apparatus according to claim 1.

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