JP2018126921A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet printer which can cope with overprint and suppress size increase of a carriage.SOLUTION: A printer related to the invention comprises a holder 70 which is provided on a carriage 60 and holds a first ink head 40 and a second ink head 50. A position of the holder 70 can be switched among plural positions including a first position and second position with respect to the carriage 60. The first position is a position where the first nozzle 41 and the second nozzle 51 are parallel to a sub scanning direction X, and a part 41a of the first nozzle 41 is arranged on an upstream side X1 of the sub scanning direction X relative to the second nozzle 51, and a part 51a of the second nozzle 51 is arranged on an upstream side X1 of the sub scanning direction X relative to the first nozzle 41. The second position is a position obtained by rotating the first position by 180 degrees.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an inkjet printer.

  2. Description of the Related Art Conventionally, ink jet printers that form images on a recording medium by overlapping different types of inks are known. For example, Patent Document 1 discloses an ink jet printer including a sub head for ground color layer printing and a sub head for image printing. In the ink jet printer disclosed in Patent Document 1, the sub-head for ground color layer printing includes a front ground color layer ink discharge port located on the downstream side in the medium transport direction and a rear ground located on the upstream side. And a color layer ink discharge port. The image print sub-head includes a front image ink discharge port located on the downstream side in the medium transport direction and a rear image ink discharge port located on the upstream side.

  In the inkjet printer disclosed in Patent Document 1, when performing overprinting with the ground color layer as the lower layer and the image as the upper layer, the ground color layer printing ink ejected from the rear ground color layer ink discharge port is used. The lower layer is printed, and the upper layer is printed with the image printing ink discharged from the front image ink discharge port. When performing overprinting with the image as the lower layer and the ground color layer as the upper layer, printing is performed with the front and rear portions of the discharge port reversed for each of the ground color layer printing sub-head and the image printing sub-head. Is called. The ink jet printer disclosed in Patent Document 1 can perform continuous overprinting without returning the medium by adopting the above-described configuration.

JP 2007-050555 A

  However, the inkjet printer disclosed in Patent Document 1 has a problem that only half of the sub-heads can be used during overprinting. Specifically, only one of the combination of the front ground color layer ink ejection port and the rear image ink ejection port or the combination of the rear ground color layer ink ejection port and the front image ink ejection port is used. Can not. Therefore, in the ink jet printer disclosed in Patent Document 1, the ink ejection efficiency during overprinting is about half that during normal printing. That means that the printing efficiency in printing is approximately halved (the printing speed is approximately halved).

  On the other hand, as a countermeasure against the above problem, for example, if the sub-head for ground color layer printing is arranged upstream in the medium conveyance direction and the sub-head for image layer printing is arranged downstream in the medium conveyance direction, the above-mentioned problem of printing efficiency However, the above configuration is not suitable for overprinting with an image as a lower layer and a ground color layer as an upper layer. Similarly, in the case of a configuration in which the sub head for image layer printing is arranged upstream in the conveyance direction of the media and the sub head for printing the ground color layer is arranged downstream in the conveyance direction of the media, the ground color layer is the lower layer and the image is printed. It is not suitable for overprinting as an upper layer. As a countermeasure, if sub-heads for ground color layer printing are provided both upstream and downstream in the conveyance direction of the medium, the carriage on which the head is mounted becomes large.

  The present invention has been made in view of such a point, and an object of the present invention is to provide an ink jet printer that can cope with both of the two patterns of overprinting and can suppress an increase in size of a carriage. .

  An inkjet printer according to the present invention includes a first ink head that has a plurality of first nozzles arranged in one direction and discharges first ink from the first nozzle toward a recording medium, and a plurality of inks arranged in one direction. A second ink head having a second nozzle for discharging the second ink from the second nozzle toward the recording medium; a carriage movable in a main scanning direction; the first ink head provided in the carriage; A holder for holding the second ink head; a main scanning direction moving device for moving the carriage in the main scanning direction; and a recording medium from the upstream in the sub-scanning direction perpendicular to the main scanning direction with respect to the carriage. A sub-scanning direction moving device that moves relatively downstream, the first ink head, the second ink head, the main scanning direction moving device, and the sub-scanning And a control device for controlling the direction moving device. In the carriage, the holder includes the plurality of first nozzles arranged in the sub-scanning direction, the plurality of second nozzles arranged in the sub-scanning direction, and a part of the plurality of first nozzles arranged in the first scanning direction. The first ink head and the first ink head so as to be positioned upstream of the two nozzles in the sub-scanning direction and a part of the plurality of second nozzles positioned downstream of the first nozzle in the sub-scanning direction; A plurality of positions including a first position where the second ink head is held, and a second position obtained by rotating the first position 180 degrees around a rotation axis perpendicular to the main scanning direction and the sub-scanning direction. It can be switched to the position. The control device includes a first print control unit and a second print control unit. The first printing control unit may move the carriage from the part of the plurality of first nozzles and the part of the first nozzle while moving the carriage in the main scanning direction when the holder is in the first position. A first print layer is formed on the recording medium by ejecting ink, and then the recording medium is moved from the upstream side to the downstream side in the sub-scanning direction with respect to the carriage, and then the carriage is moved to the carriage. While moving in the main scanning direction, the second ink is discharged from the part of the plurality of second nozzles and the other part of the first nozzle located further downstream in the sub-scanning direction than the other part of the first nozzle. By discharging, a second print layer is formed on the first print layer. The second printing control unit may move the carriage from the part of the plurality of second nozzles to the second part while moving the carriage in the main scanning direction when the holder is in the second position. The second print layer is formed on the recording medium by ejecting ink, and then the recording medium is moved from the upstream side to the downstream side in the sub-scanning direction with respect to the carriage, and then the carriage is moved. The first ink from the other part of the plurality of first nozzles and the other part of the second nozzle located downstream in the sub-scanning direction while moving in the main scanning direction. Is ejected to form the first printed layer on the second printed layer.

  Another ink jet printer according to the present invention includes a first ink head having a plurality of first nozzles arranged in one direction and discharging the first ink from the first nozzle toward a recording medium, and in one direction. A second ink head having a plurality of second nozzles arranged side by side to eject the second ink from the second nozzle toward the recording medium; a carriage movable in a main scanning direction; and the carriage provided on the carriage. A holder for holding one ink head and the second ink head, a main scanning direction moving device for moving the carriage in the main scanning direction, and sub-scanning the recording medium perpendicular to the main scanning direction with respect to the carriage A sub-scanning direction moving device that relatively moves from upstream to downstream in the direction, the first ink head, the second ink head, the main scanning direction moving device, and And a control device for controlling the serial sub-scanning direction moving device. In the carriage, the holder includes the plurality of first nozzles arranged in the sub-scanning direction, the plurality of second nozzles arranged in the sub-scanning direction, and the plurality of first nozzles from the second nozzle. The first position at which the first ink head and the second ink head are held so as to be positioned upstream of the sub-scanning direction, and the first position with respect to the main scanning direction and the sub-scanning direction It is configured to be switchable to a plurality of positions including a second position rotated 180 degrees around a vertical rotation axis. The control device includes a first print control unit and a second print control unit. The first print control unit discharges the first ink from the plurality of first nozzles while moving the carriage in the main scanning direction when the holder is at the first position. A first printing layer is formed on the recording medium, and then the recording medium is moved from the upstream side to the downstream side in the sub-scanning direction with respect to the carriage, and then the carriage is moved in the main scanning direction. The second print layer is formed on the first print layer by discharging the second ink from the second nozzle. The second print control unit discharges the second ink from the plurality of second nozzles while moving the carriage in the main scanning direction when the holder is at the second position. The second print layer is formed thereon, and then the recording medium is moved from the upstream side in the sub-scanning direction to the downstream side with respect to the carriage, and then the carriage is moved in the main scanning direction while moving the carriage in the main scanning direction. The first printing layer is formed on the second printing layer by discharging the first ink from a plurality of first nozzles.

  According to the above-described ink jet printer, the first ink head for ejecting the first ink and the second ink head for ejecting the second ink are moved to the “first position” and the “second position” which are shifted from each other by 180 degrees on the carriage. The holder is configured to be switchable. In the “first position”, the first ink head and the second ink head are parallel to the sub-scanning direction, and at least a part of the first nozzle is located upstream of the second nozzle in the sub-scanning direction, At least a part of the second nozzle is held so as to be positioned downstream of the first nozzle in the sub-scanning direction. The “second position” is a position obtained by rotating the “first position” by 180 degrees around a rotation axis perpendicular to the main scanning direction and the sub-scanning direction. Therefore, in the “second position”, the first ink head and the second ink head are parallel to the sub-scanning direction, and at least a part of the second nozzle is upstream of the first nozzle in the sub-scanning direction. The first nozzle is held so that at least a part of the first nozzle is positioned downstream of the second nozzle in the sub-scanning direction. When the holder is in the “first position”, the control device according to the ink jet printer performs overprinting in which the printing layer with the first ink is printed on the lower layer and the printing layer with the second ink is printed on the upper layer. Is set to do. In addition, when the holder is in the “second position”, the control device is configured to perform overprinting in which a printing layer with the second ink is printed on the lower layer and a printing layer with the first ink is printed on the upper layer. Has been. With the configuration and control described above, the inkjet printer ejects the ink printed on the lower layer in both the overprinting when the first ink is printed on the lower layer and the second ink is printed on the lower layer. It is possible to perform printing by disposing the nozzle to be arranged upstream in the sub-scanning direction from the nozzle that ejects the ink printed on the upper layer. Therefore, the ink jet printer can continuously perform printing in both the overprinting when the first ink is printed on the lower layer and the second ink is printed on the lower layer. Further, according to the ink jet printer, since the holder 70 is configured to be switchable between the “first position” and the “second position”, one of the first ink and the second ink is ejected. It is not necessary to provide the ink head to be provided on both the upstream side and the downstream side in the sub-scanning direction of the ink head that discharges the other ink. Therefore, an increase in the size of the carriage can be suppressed.

1 is a front view of an ink jet printer according to a first embodiment. It is the model which shows the structure of a carriage, Comprising: It is the figure which looked at the carriage from upper direction. It is the model which shows the structure of a carriage, Comprising: It is the figure which looked at the carriage from the front. FIG. 6 is a schematic diagram illustrating an arrangement of ink heads at a “first position”. It is a block diagram of a printer. FIG. 6 is a schematic diagram illustrating an arrangement of ink heads at an intermediate position between “first position” and “second position” and at “second position”. It is the schematic diagram which looked at the carriage periphery at the time of 1st overlap printing from upper direction. It is the schematic diagram which looked at the carriage periphery at the time of 2nd overlap printing from the upper direction. It is a block diagram of a control device concerning a 2nd embodiment. It is an example of the image printed on a recording medium. It is a schematic diagram showing the arrangement of an image printed on a recording medium and an ink head.

  Hereinafter, an inkjet printer according to some embodiments will be described with reference to the drawings. It should be noted that the embodiments described herein are not intended to limit the present invention. Moreover, the same code | symbol is attached | subjected to the member and site | part which show | plays the same effect | action, and the overlapping description is abbreviate | omitted or simplified suitably. In the following description, when the ink jet printer is viewed from the front, the direction away from the ink jet printer is referred to as the front, and the direction approaching the ink jet printer is referred to as the rear. In the drawings, the symbol Y indicates the main scanning direction, and the symbol X indicates the sub-scanning direction X orthogonal to the main scanning direction Y. Further, symbols F, Rr, L, and R in the drawings represent front, rear, left, and right, respectively. However, these are only directions for convenience of explanation, and do not limit the installation mode of the ink jet printer.

(First embodiment)
FIG. 1 is a front view of a large-sized inkjet printer (hereinafter referred to as “printer”) 10 according to the first embodiment. The printer 10 sequentially moves the roll-shaped recording medium 5 forward (on the downstream X2 side in the sub-scanning direction X, see FIG. 2), and is mounted on a carriage 60 that moves in the main scanning direction Y. And an image is printed on the recording medium 5 by discharging an ink from the 2nd ink head 50 (refer FIG. 4).

  The recording medium 5 is an object on which an image is printed. The recording medium 5 is not particularly limited. The recording medium 5 may be, for example, paper such as plain paper or inkjet printing paper, a transparent sheet such as resin or glass, or a sheet made of metal or rubber. It may be.

  As shown in FIG. 1, the printer 10 includes a printer main body 10a and legs 11 that support the printer main body 10a. The printer main body 10a extends in the main scanning direction Y. The printer main body 10 a includes a guide rail 21 and a carriage 60 engaged with the guide rail 21. The guide rail 21 extends in the main scanning direction Y. The guide rail 21 guides the movement of the carriage 60 in the main scanning direction Y. An endless belt 22 is fixed to the carriage 60. The belt 22 is wound around a pulley 23 a provided on the right side of the guide rail 21 and a pulley 23 b provided on the left side. A carriage motor 24 is attached to the right pulley 23a. The carriage motor 24 is electrically connected to the control device 100. The carriage motor 24 is controlled by the control device 100. When the carriage motor 24 is driven, the pulley 23a rotates and the belt 22 travels. As a result, the carriage 60 moves in the main scanning direction Y along the guide rail 21. Thus, when the carriage 60 moves in the main scanning direction Y, the first ink head 40 (see FIG. 4) and the second ink head 50 (see FIG. 4) mounted on the carriage 60 also move in the main scanning direction Y. Moving. In the present embodiment, the belt 22, the pulley 23a, the pulley 23b, and the carriage motor 24 move the first ink head 40 and the second ink head 50 mounted on the carriage 60 and the carriage 60 in the main scanning direction Y. 2 is an example of a direction moving device 20.

  A platen 12 is disposed below the carriage 60. The platen 12 extends in the main scanning direction Y. The recording medium 5 is placed on the platen 12. A pinch roller 31 is provided above the platen 12 to press down the recording medium 5 from above. The pinch roller 31 is disposed behind the carriage 60. A grid roller 32 is provided on the platen 12. The grid roller 32 is disposed below the pinch roller 31. The grid roller 32 is provided at a position facing the pinch roller 31. The grid roller 32 is connected to a feed motor 33 (see FIG. 5). The grid roller 32 is formed to be rotatable by receiving the driving force of the feed motor 33. The feed motor 33 is electrically connected to the control device 100. The feed motor 33 is controlled by the control device 100. When the grid roller 32 rotates while the recording medium 5 is sandwiched between the pinch roller 31 and the grid roller 32, the recording medium 5 is conveyed in the sub-scanning direction X. In the present embodiment, the pinch roller 31, the grid roller 32, and the feed motor 33 are an example of the sub-scanning direction moving device 30 that moves the recording medium 5 in the sub-scanning direction X.

  The carriage 60 is provided with a holder 70. The holder 70 is a member that holds the first ink head 40 (see FIG. 4) and the second ink head 50 (see FIG. 4) and switches the arrangement of the first ink head 40 and the second ink head 50. The holder 70 is supported by the carriage 60 from above while holding the first ink head 40 and the second ink head on the lower surface. Specifically, the holder 70 is supported by the carriage 60 so as to be rotatable in the horizontal direction.

  FIG. 2 is a schematic diagram illustrating the configuration of the carriage 60. In FIG. 2, the carriage 60 is viewed from above the printer 10. Therefore, in FIG. 2, the carriage 60 is visible on the front surface and the holder 70 is visible on the rear surface. FIG. 3 is a schematic view of the carriage 60 as viewed from the front F of the printer 10. As shown in FIGS. 2 and 3, the carriage 60 includes a rotation mechanism 80. The rotation mechanism 80 is a mechanism that rotates the holder 70. The rotation mechanism 80 includes a rotation shaft 81, a rotation drive device 82, and a position detection device 83.

  The holder 70 is configured to rotate about a rotation shaft 81 with respect to the carriage 60. Specifically, as shown in FIG. 3, the rotation shaft 81 is installed vertically, and the holder 70 is fixed to the rotation shaft 81. The rotation shaft 81 is rotatably inserted into the carriage 60. Therefore, the holder 70 rotates with respect to the carriage 60 as the rotation shaft 81 rotates. The rotating shaft 81 passes through the carriage 60 and protrudes above the upper surface of the carriage 60. A rotation drive device 82 is connected to the upper end of the rotation shaft 81 protruding above the upper surface of the carriage 60. The rotational drive device 82 includes, for example, a motor 82a and a belt 82b. A pulley 81a around which the belt 82b is wound is provided at the upper end of the rotating shaft 81. The belt 82b is also wound around the drive shaft of the motor 82a. The rotating shaft 81 is rotated when the belt 82b is driven by the motor 82a. The rotation drive device 82 is configured to rotate the rotation shaft 81 by the mechanism as described above, for example. However, the configuration of the rotary drive device 82 is not limited to the above mechanism. For example, a mechanism using a sprocket instead of a belt and a pulley may be used.

  The rotation mechanism 80 further includes a position detection device 83. The position detection device 83 is a mechanism that detects which one of the rotation positions of the holder 70 is a predetermined rotation position. More specifically, this is a mechanism for detecting whether the holder 70 is in a “first position”, “second position”, which will be described later, or an intermediate position that is neither of them. The position detection device 83 includes, for example, a limit switch that is pressed when the holder 70 is disposed at the “first position” and a limit switch that is pressed when the holder 70 is disposed at the “second position”. I have. The holder 70 is provided with a protrusion or the like for pressing the limit switch. The position detection device 83 is connected to the control device 100 (see FIG. 1), and the control device 100 grasps the rotational position of the holder 70 based on a signal from the position detection device 83. However, the configuration of the position detection device 83 is not limited to the configuration described above, and may be, for example, a photoelectric sensor or the like.

  The first ink head 40 and the second ink head 50 are held on the lower surface of the holder 70. FIG. 4 is a schematic view showing the arrangement of the ink heads in the holder 70, and is a view of the holder 70 as viewed from the lower D toward the upper U. As described above, since the holder 70 rotates in the horizontal direction, the arrangement of the ink head changes with respect to the printer main body 10a. FIG. 4 illustrates the case of the “first position”. As shown in FIG. 4, in the “first position”, the first ink head 40 is disposed near the left rear corner of the lower surface of the holder 70. The second ink head 50 is disposed on the right front side of the first ink head 40.

  The first ink head 40 is composed of one ink head. In the present embodiment, the first ink head 40 ejects so-called special color ink for changing the color tone and design of a color image. The special color ink is an example of “first ink”. The special color ink is ink of a color other than process color ink such as CMYK. The spot color ink includes, for example, metallic ink such as silver ink and gold ink, transparent ink, and the like in addition to white ink as a representative one. In the present embodiment, the first ink head 40 has one ink head, but is not limited thereto. The number of ink heads of the first ink head 40 may be two or more, for example. The color tone of the special color ink is not limited at all.

  As shown in FIG. 4, the first ink head 40 in the “first position” has a plurality of nozzles 41 arranged in the sub-scanning direction X. Hereinafter, the nozzles of the first ink head 40 will be referred to as first nozzles 41 as appropriate. In the first ink head 40 according to the present embodiment, a plurality of first nozzles 41 are arranged in a line to form a nozzle line. However, the arrangement of the first nozzles 41 is not limited to one row. For example, the first ink head 40 may have two or more nozzle rows. Hereinafter, the arrangement direction of the first nozzles 41 not depending on the rotation of the holder 70 will be referred to as a nozzle row direction N as appropriate.

  As shown in FIG. 4, the second ink head 50 includes a plurality of ink heads 50C, 50M, 50Y, and 50K. The plurality of ink heads 50C, 50M, 50Y, and 50K are arranged in a direction orthogonal to the nozzle row direction N (in the “first position”, the main scanning direction Y). The plurality of ink heads 50C, 50M, 50Y, and 50K each discharge process color ink for forming a color image. The process color ink is an example of a “second ink”. In the present embodiment, the ink head 50C discharges cyan ink. The ink head 50M discharges magenta ink. The ink head 50Y discharges yellow ink. The ink head 50K discharges black ink. However, the number of ink heads of the second ink head 50 is not limited to four. The number of ink heads of the second ink head 50 may be, for example, five or more, or one (for example, only the ink head 50K). Further, the color tone of the process color ink is not limited at all.

  As shown in FIG. 4, each of the plurality of ink heads 50C, 50M, 50Y, and 50K has a plurality of nozzles 51 arranged in the nozzle row direction N (the sub-scanning direction X in the “first position”). Yes. Hereinafter, the nozzles provided in each ink head of the second ink head 50 will be referred to as second nozzles 51 as appropriate. In the present embodiment, in each of the ink heads 50C, 50M, 50Y, and 50K, a plurality of second nozzles 51 are arranged in a line to form a nozzle line. The direction of the nozzle row of the second nozzle 51 is parallel to the nozzle row direction N of the first nozzle 41. In the present embodiment, the second nozzles 51 of the plurality of ink heads 50 </ b> C, 50 </ b> M, 50 </ b> Y, and 50 </ b> K constituting the second ink head 50 are arranged at positions aligned in the nozzle row direction N. The lengths of the plurality of ink heads 50C, 50M, 50Y, and 50K in the nozzle row direction N are the same, and the number of the second nozzles 51 is also the same. Further, the length of each ink head of the second ink head 50 and the first ink head 40 in the nozzle row direction N is the same, and the number of the first nozzles 41 and the respective ink heads of the second ink head 50 are provided. The number of second nozzles 51 is also the same.

  In FIG. 4, ten nozzles are shown in each of the first ink head 40 and the second ink heads 50C, 50M, 50Y, and 50K, but in reality, a larger number (eg, 360) of nozzles. Is formed. However, the number of nozzles is not limited at all.

  The first ink head 40 and the second ink head 50 are arranged at positions shifted from each other in the nozzle row direction N. Therefore, as shown in FIG. 4, when the direction on the first nozzle 41 side in the nozzle row direction N is referred to as the N1 direction and the direction on the second nozzle 51 side as the N2 direction, a part of the first nozzle 41 is The second nozzle 51 protrudes in the N1 direction (hereinafter, the portion of the first nozzle 41 protruding from the second nozzle 51 will be referred to as a first protruding portion 41a as appropriate). Further, a part of the second nozzle 51 protrudes in the N2 direction from the first nozzle 41 (hereinafter, a portion protruding from the first nozzle 41 of the second nozzle 51 is appropriately referred to as a second protruding portion 41a). ). According to the arrangement of the ink heads shown in FIG. 4, six out of ten first nozzles 41 belong to the first projecting portion 41a. That is, 60% of the first nozzles 41 with respect to the entire first nozzle 41 belong to the first protruding portion 41a. The remaining 40% of the first nozzle 41 belongs to a portion of the first nozzle 41 that overlaps with the second nozzle 51 in the nozzle row direction N (hereinafter referred to as a first overlapping portion 41b). Similarly, according to the arrangement of the ink heads shown in FIG. 4, six out of ten second nozzles 51 belong to the second projecting portion 51a. That is, 60% of the second nozzles 51 with respect to the entire second nozzle 51 belong to the second protruding portion 51a. The remaining 40% of the second nozzle 51 belongs to a portion of the second nozzle 51 that overlaps the first nozzle 41 in the nozzle row direction N (hereinafter referred to as a second overlapping portion 51b).

  Inside the first ink head 40 and the second ink heads 50C, 50M, 50Y, 50K, an actuator (not shown) including a piezoelectric element or the like is provided. The actuator is electrically connected to the control device 100. The actuator is controlled by the control device 100. When the actuator is driven, ink is ejected from the first nozzle 41 of the first ink head 40 and the second nozzle 51 of the second ink heads 50C, 50M, 50Y, and 50K toward the recording medium 5.

  Each of the ink heads 40, 50C, 50M, 50Y, and 50K communicates with an ink cartridge (not shown) through an ink supply path (not shown). The ink cartridge is detachably disposed at the right end portion of the printer main body 10a, for example. The material of the ink is not limited at all, and various materials conventionally used as the ink material of the ink jet printer can be used. The ink may be, for example, a solvent (solvent) pigment ink or an aqueous pigment ink, an aqueous dye ink, or an ultraviolet curable pigment ink that is cured by receiving ultraviolet rays.

  As shown in FIG. 1, the printer 10 includes a heater 35. The heater 35 is provided below the platen 12. The heater 35 is disposed in front of the grid roller 32. The heater 35 heats the platen 12. By heating the platen 12, the recording medium 5 disposed on the platen 12 and the ink that has landed on the recording medium 5 are heated, and the drying of the ink is promoted. The heater 35 is electrically connected to the control device 100. The heating temperature of the heater 35 is controlled by the control device 100.

  As shown in FIG. 1, an operation panel 150 is provided at the right end of the printer main body 10a. The operation panel 150 is provided with a display unit for displaying the device status, input keys operated by the user, and the like. Inside the operation panel 150 is accommodated a control device 100 that controls various operations of the printer 10. FIG. 5 is a block diagram of the printer 10 according to the present embodiment. As shown in FIG. 5, the control device 100 includes a feed motor 33, a carriage motor 24, a heater 35, ink heads 50 </ b> C to 50 </ b> K of the first ink head 40 and the second ink head 50, and a motor 82 a of the rotation driving device 82. They are connected to each other and can be controlled. The control device 100 includes a mode selection unit 110, a print control unit 120, and a rotation control unit 130.

  The configuration of the control device 100 is not particularly limited. The control device 100 is, for example, a microcomputer. The hardware configuration of the microcomputer is not particularly limited. For example, an interface (I / F) that receives print data from an external device such as a host computer, and a central processing unit (CPU: central processing unit) that executes control program instructions processing unit), ROM (read only memory) storing a program executed by the CPU, RAM (random access memory) used as a working area for developing the program, memory for storing the program and various data, etc. And a storage device. The control device 100 is not necessarily provided inside the printer main body 10a. For example, a computer installed outside the printer main body 10a and connected to be communicable with the printer main body 10a via a wire or wirelessly. It may be.

  The mode selection unit 110 is a part where a printing method is selected. In this embodiment, the printing method is classified into “normal printing” and “overlapping printing”. Furthermore, “overlap printing” is classified into “first overprint” and “second overprint”. In “first overprinting”, a printing layer (corresponding to “first printing layer” of the present invention) of the special color ink ejected by the first ink head 40 is printed as a lower layer, and on the printing layer of the special color ink, A print layer (corresponding to the “second print layer” of the present invention) of process color ink discharged from the second ink head 50 is printed in an overlapping manner. In “second overprinting”, a process color ink print layer (second print layer) is printed as a lower layer, and a special color ink print layer (first print layer) is overlaid on the process color ink print layer. Printed. “Normal printing” is a printing method in which only one layer is printed, unlike the two-pattern overprinting. Note that the printing method may be incorporated in the print data in advance, or may be appropriately selected by the operator.

  The print control unit 120 controls the ink heads 40 and 50 </ b> C to 50 </ b> K, the carriage motor 24, and the feed motor 33 to perform printing on the recording medium 5, and controls the heater 35 to eject ink discharged onto the recording medium 5. It is a part which dries. As shown in FIG. 5, the print control unit 120 includes a first print control unit 121, a second print control unit 122, and a third print control unit 123. The first print control unit 121 controls the first ink head 40, the second ink head 50, the carriage motor 24, the feed motor 33, and the heater 35 to perform printing in printing in the “first overlap printing” mode. It is a part. The second printing control unit 122 controls the first ink head 40, the second ink head 50, the carriage motor 24, the feed motor 33, and the heater 35 in the printing in the “second overprinting” mode to perform printing. It is a part. The third printing control unit 123 is a part that controls the second ink head 50, the carriage motor 24, the feed motor 33, and the heater 35 to perform printing in printing in the “normal printing” mode. The print control unit 120 controls each unit with a different movement for each print mode selected by the mode selection unit 110. The movement of each part for each print mode will be described later.

  The rotation control unit 130 is a part that controls the rotation driving device 82 to rotate the holder 70. The rotation control unit 130 arranges the holder 70 at the “first position” when “first overprint” is selected as the printing method. Furthermore, the rotation control unit 130 places the holder 70 at the “second position” when “second overprinting” is selected as the printing method. Further, when “normal printing” is selected as the printing method, the rotation control unit 130 may place the holder 70 at either the “first position” or the “second position”. In the “first position”. Details of the “second position” will be described later. The rotation control unit 130 receives a signal from the position detection device 83 of the rotation mechanism 80 and displays the position of the holder 70 on the operation panel 150, for example.

  When “normal printing” is selected by the mode selection unit 110, as described above, the rotation control unit 130 arranges the holder 70 at the “first position”. In the “first position”, the first ink head 40 and the second ink heads 50C to 50K are arranged as shown in FIG. In “normal printing”, only process color ink is used. In “normal printing”, the print control unit 120 drives the carriage motor 24 to move the carriage 60 in the main scanning direction Y, and drives the actuator to drive the ink heads 50C, 50M, and 50Y of the second ink head 50. The process color ink is ejected from 50K, and the process color ink is landed on the printing surface of the recording medium 5. Further, the print control unit 120 controls the feed motor 33 so that the recording medium 5 is sequentially sent forward F (downstream X2 side in the sub-scanning direction X). For example, the print control unit 120 moves the carriage 60 once or a plurality of times in the main scanning direction Y until the recording medium 5 is fed forward F once.

  By the way, the mode selection unit 110 according to the present embodiment is configured to select not only “normal printing” as described above, but also “overlay printing” in which an upper layer image is superimposed on a lower layer image. ing. In the “first overprinting” of the “overprinting”, the ground color is first printed on the recording medium 5 with the special color ink. Next, an image is printed with the process color ink on the special color ink ejected onto the recording medium 5. In the “second overprinting” of the “overprinting”, conversely, the special color ink is overprinted as an upper layer on the lower layer on which the image of the process color ink is printed. In any case, the purpose of overprinting is to give a specific visual effect to the image. For example, when the recording medium 5 is a transparent sheet, the background color is given to the image.

  In the “overprinting”, the conventional printer, for example, divides each of the first ink head and the second ink head into two in the upstream / downstream direction in the sub-scanning direction, and the upstream side and the second side of the first ink head. The special color ink for the ground color and the process color ink for the image are ejected by a combination of the downstream side of the ink head or the downstream side of the first ink head and the upstream side of the second ink head. With such a configuration, the conventional printer can continuously perform overprinting without returning the recording medium.

  However, the conventional ink jet printer can use only one of the upstream and downstream nozzles in the sub-scanning direction in both the first ink head and the second ink head during overprinting. That is, the conventional ink jet printer can use only half of the nozzles during overprinting. Therefore, the ink ejection efficiency during overprinting is about half that during normal printing. That means that the printing efficiency is halved.

  As a countermeasure against the printing efficiency problem, for example, if the ink head that discharges special color ink is arranged upstream in the sub-scanning direction and the ink head that discharges process color ink is arranged downstream in the sub-scanning direction, the printing efficiency can be improved. Although the problem is solved, the above configuration is not suitable for overprinting with an image as a lower layer and a ground color layer as an upper layer. Similarly, in a configuration in which an ink head that discharges process color ink is arranged upstream in the sub-scanning direction and an ink head that discharges special color ink is arranged downstream in the sub-scanning direction, the background color layer is the lower layer and the image is It is not suitable for overprinting as an upper layer. As a countermeasure, if ink heads for discharging special color inks are provided both upstream and downstream in the sub-scanning direction, the carriage on which the ink heads are mounted becomes large.

  Therefore, the printer 10 according to the present embodiment holds the first ink head 40 and the second ink head 50 and can hold the first ink head 40 and the second ink head 50 at a plurality of positions. It has. Here, the plurality of positions are a “first position” and a “second position”. However, the plurality of positions may include positions other than the “first position” and the “second position”. In the “first position”, the first nozzle 41 and the second nozzle 51 are parallel to the sub-scanning direction X, and the first protruding portion 41 a of the first nozzle 41 is more sub-scanning direction X than the second nozzle 51. The second protruding portion 51 a of the second nozzle 51 is located on the downstream X2 side in the sub-scanning direction X with respect to the first nozzle 41. On the other hand, the “second position” is a position obtained by rotating the “first position” 180 degrees in the horizontal direction. That is, in the “second position”, the first nozzle 41 and the second nozzle 51 are parallel to the sub-scanning direction X, and the second projecting portion 51 a of the second nozzle 51 is more in the sub-scanning direction than the first nozzle 41. This is a position where the first protruding portion 41a of the first nozzle 41 is disposed on the downstream X2 side in the sub-scanning direction X with respect to the second nozzle 51. The first print control unit 121 according to the present embodiment is set to perform “first overlap printing” when the holder 70 is disposed at the “first position”, and the second print control unit 122. Is set to perform “second overprinting” when the holder 70 is arranged at the “second position”.

  According to the printer 10 according to the present embodiment, the rotation of the holder 70 causes the first ink head 40 and the second ink head 50 to be arranged such that the protruding portion 41a of the first nozzle 41 is in the sub-scanning direction than the second nozzle 51. It is possible to switch between the “first position” on the upstream X1 side of X and the “second position” on which the protruding portion 51a of the second nozzle 51 is on the upstream X1 side in the sub-scanning direction X with respect to the first nozzle 41. . By the above switching, in both the “first overprint” and the “second overprint”, the nozzle that ejects the ink that is printed in the lower layer ejects the ink that is printed in the upper layer. It is possible to perform printing by arranging the nozzle upstream of the nozzle to perform in the sub-scanning direction. Accordingly, in any one of the “first overprint” and the “second overprint”, the overprint can be continuously performed. In addition, according to the present embodiment, in order to support both “first overlap printing” and “second overlap printing”, the ink head that discharges the special color ink is sub-scanned by the ink head that discharges the process color ink. There is no need to provide both the upstream side and the downstream side in the direction, and the enlargement of the carriage can be suppressed.

  FIG. 6 is a schematic diagram showing the arrangement of the ink heads at an intermediate position between the “first position” and the “second position” and at the “second position”. FIG. 6A shows the state of the carriage 60 at an intermediate position between the “first position” and the “second position”. FIG. 6B shows the state of the carriage 60 at the “second position”. FIG. 6 is also a view of the lower surface of the carriage 60 as viewed upward U. As shown in FIG. 6, the holder 70 is configured to rotate horizontally around the rotation shaft 81. The first ink head 40 and the second ink head 50 that are held in parallel in the sub-scanning direction X at the “first position” are temporarily not parallel to the sub-scanning direction X as the holder 70 rotates. When the holder 70 stops at the “second position”, the holder 70 is again arranged parallel to the sub-scanning direction X. The “first position” and the “second position” are shifted by 180 degrees. In the “second position”, the protruding portion 51 a of the second nozzle 51 is disposed on the upstream X1 side in the sub-scanning direction X with respect to the first nozzle 41. Further, the protruding portion 41 a of the first nozzle 41 is disposed on the downstream X2 side in the sub-scanning direction X with respect to the second nozzle 51.

  FIG. 7 is a schematic view of the periphery of the carriage 60 viewed from above U in “first overprinting”. In FIG. 7, black circles applied to the first nozzle 41 and the second nozzle 51 indicate that ink is being ejected from the nozzle. In the carriage 60 shown in FIG. 7, the holder 70 is disposed at the “first position”. In “first overlap printing”, the first print control unit 121 controls each unit. In “first overprinting”, first of all, among the first nozzles 41, a first used nozzle comprising a nozzle 41 belonging to the first protruding portion 41a and a nozzle 41 belonging to the N1 side half 41c of the first overlapping portion 41b. The spot color ink is ejected from 41d. FIG. 7A illustrates the first pass of “first overlap printing”. As shown in FIG. 7A, the special color ink is ejected from the first use nozzle 41d to the area E1 on the recording medium 5. That is, the lower layer is formed by the printing layer of the special color ink. According to the embodiment, the ratio of the first use nozzle 41d to the entire first nozzle 41, that is, the nozzle use rate of the first ink head 40 is 80%.

  After the ejection shown in FIG. 7A, the first printing control unit 121 drives the feed motor 33 to move the recording medium 5 forward F once. The moving distance at this time is the length of the first use nozzle 41d. After the recording medium 5 is moved, the first printing control unit 121 causes some of the nozzles 51 of the second ink heads 50C to 50K to discharge process color ink. Specifically, the first printing control unit 121 uses the second nozzle 51 to include the second nozzle 51 that belongs to the second protruding portion 51a and the nozzle 51 that belongs to the N2 side half 51c of the second overlapping portion 51b. Process color ink is ejected from the nozzle 51d. FIG. 7B is a diagram illustrating a state on the recording medium 5 at the time of the next pass after the time point illustrated in FIG. In FIG. 7B, process color ink is ejected from the second use nozzles 51d of the second ink heads 50C to 50K toward the region E1. That is, the upper layer is formed by the printing layer (image layer) of process color ink. At the same time, the spot color ink is ejected from the first use nozzle 41d of the first ink head 40 toward the region E2 next to the region E1 (on the upstream X1 side in the sub-scanning direction X). Thus, in the printer 10 according to the present embodiment, in the “first overprinting”, a part of the first nozzle 41 is arranged on the upstream X1 side in the sub-scanning direction X with respect to the second nozzle 51, and the second nozzle Since a part of 51 is arranged on the downstream X2 side in the sub-scanning direction X from the first nozzle 41, printing can be continuously performed without returning the recording medium 5. Note that the nozzle usage rate of the second ink head 50 is also 80% as in the case of the first ink head 40.

  On the other hand, in “second overprinting”, the process color ink is ejected before the spot color ink at the same point on the recording medium 5. Therefore, in the “second overprinting”, it is preferable that the second use nozzle 51d is arranged on the upstream X1 side in the sub-scanning direction X with respect to the first use nozzle 41d.

  FIG. 8 is a schematic view of the periphery of the carriage 60 viewed from above U in “second overprinting”. As in FIG. 7, in FIG. 8, the black circles applied to the first nozzle 41 and the second nozzle 51 indicate that ink is being ejected from the nozzle. In the carriage 60 shown in FIG. 8, the holder 70 is disposed at the “second position”. In the “second position”, the second use nozzle 51d is arranged on the upstream X1 side in the sub-scanning direction X with respect to the first use nozzle 41d. In “second overprinting”, the second printing control unit 122 controls each unit. In “second overprinting”, first, process color ink is ejected from the second use nozzle 51d. FIG. 8A illustrates the first pass of “second overprint”. As shown in FIG. 8A, the process color ink is ejected from the first use nozzle 41d to the area E1 on the recording medium 5. That is, the lower layer is formed by the printing layer of process color ink. After the ejection shown in FIG. 8A, the second print control unit 122 drives the feed motor 33 to move the recording medium 5 forward F once. The moving distance at this time is the length of the second use nozzle 51d. FIG. 8B is a diagram showing a state on the recording medium 5 at the time of the next pass after the time point shown in FIG. As shown in FIG. 8B, after the recording medium 5 is moved, the second print control unit 122 ejects the special color ink from the first use nozzle 41d toward the region E1, and the print layer using the special color ink. To form the upper layer. At the same time, the process color ink is ejected from the second use nozzle 51d toward the area E2 next to the area E1, and a lower layer is formed by the print layer of the process color ink. As described above, the printer 10 according to the present embodiment can perform continuous printing without returning the recording medium 5 even in “second overlap printing”.

  Furthermore, according to the printer 10 according to the present embodiment, since the holder 70 rotates, the ink head that discharges the special color ink is only on one side in the nozzle row direction N of the ink head that discharges the process color ink (this book In the embodiment, it is sufficient if it is arranged only on the N1 side. In other words, it is not necessary to dispose the ink head that discharges the special color ink upstream and downstream of the ink head that discharges the process color ink. Thereby, the enlargement of the carriage can be suppressed.

  In the printer 10 according to the present embodiment, the holder 70 is configured to be rotatable around a rotation axis 81 that is perpendicular to the main scanning direction Y and the sub-scanning direction X (perpendicular to the present embodiment). The printer 10 includes a rotation drive device 82 that rotates the holder 70. Therefore, the printer 10 according to the present embodiment can easily and automatically switch the position of the holder 70. Furthermore, the printer 10 according to the present embodiment includes a mode selection unit 110 and a rotation control unit 130, and automatically selects the position of the holder 70 depending on whether the print mode is “first overlap printing” or “second overlap printing”. can do.

  In the printer 10 according to the present embodiment, the ratio of the first protruding portion 41a to the entire first nozzle 41 and the ratio of the second protruding portion 51a to the entire second nozzle 51 are 60%. The said ratio is not restricted to this. The ratio is determined based on a balance between printing efficiency and carriage size. The case where the ratio is set to 50% or more is a case where printing efficiency is important. If the ratio of the first protruding portion 41a to the entire first nozzle 41 and the ratio of the second protruding portion 51a to the entire second nozzle 51 are set to 50% or more, the printing efficiency can be increased. On the contrary, when the ratio is set to less than 50%, it is a case where importance is given to miniaturization of the carriage. If the ratio of the first protruding portion 41a to the entire first nozzle 41 and the ratio of the second protruding portion 51a to the entire second nozzle 51 are set to less than 50%, the length of the carriage 60 in the sub-scanning direction X is shortened. can do.

(Second Embodiment)
The second embodiment is an embodiment capable of performing both “first overprint” and “second overprint” based on the same image data. Specifically, in the embodiment, the same image can be printed from the same image data even if the arrangement of the ink head relative to the printer main body is changed by the rotation of the ink head. The printer 10 according to the present embodiment is common to the printer 10 according to the first embodiment except for the members related to the above differences. Therefore, in the following description of the second embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted or simplified.

  FIG. 9 is a block diagram illustrating a configuration of the control device 100 according to the present embodiment. As shown in FIG. 9, the control device 100 according to the present embodiment includes an image data processing unit 140. The image data processing unit 140 according to the present embodiment is a part that creates rotated image data obtained by rotating image data of an image printed on the recording medium 5 by 180 degrees around a rotation axis perpendicular to the image. The image data processing unit 140 further includes an image data receiving unit 141 and a rotated image data generating unit 142.

  The image data receiving unit 141 is a part that receives image data for printing an image formed by process color ink and special color ink. The image data is image data created for either one of “first overlap printing” and “second overlap printing”.

  The rotated image data generation unit 142 is a part that generates image data of a rotated image obtained by rotating the image 180 degrees around a rotation axis perpendicular to the image. The first print control unit 121 and the second print control unit 122 perform printing by controlling each unit based on one of the image data and the rotated image data. Specifically, when the image data is created as image data for “first overlap printing”, the first print control unit 121 performs printing based on the image data, and the second print control unit 122. Performs printing based on the rotated image data. Conversely, when the image data is created as image data for “second overprinting”, the second print control unit 122 performs printing based on the image data, and the first print control unit 121. Performs printing based on the rotated image data.

  FIG. 10 is an example of an image printed on the recording medium 5. Here, the image A shown in FIG. 10A is an image created as printed by the “first overlap printing”. An image B shown in FIG. 10B is a rotated image obtained by converting the image A by the rotated image data generation unit 142. As shown in FIG. 10, the rotated image B is an image obtained by rotating the image A by 180 degrees. The rotated image B is the same image as the image A, but is different from the image A in the printing direction (direction related to the sub-scanning direction X).

  In the case of the example shown in FIG. 10, the printer 10 according to the present embodiment performs printing based on the data of the image A when printing an image by “first overlap printing”. On the other hand, when printing an image by “second overprinting”, printing is performed based on the data of the rotated image B formed by converting the image A data by the rotated image data generation unit 142.

  Furthermore, the printer 10 according to the present embodiment is set so that the printing directions are different between “first overlap printing” and “second overlap printing”. FIG. 11 is a schematic diagram showing an arrangement of an image printed on the recording medium 5 and an ink head. In FIG. 11, the recording medium 5 and the carriage 60 are viewed from above U. FIG. 11A is a schematic diagram in “first overlap printing”, and an image to be printed is an image A. FIG. An arrow shown in the vicinity of the carriage 60 is an arrow indicating a printing direction in “first overlap printing”. As shown in FIG. 11A, the printing direction in “first overlap printing” is one of the main scanning directions Y and the Y1 direction. The Y1 direction coincides with the right side R of the printer 10. Hereinafter, the Y1 direction is referred to as a first main scanning direction Y1. In the “first overlap printing”, the printer 10 according to the present embodiment performs printing only when the carriage 60 is scanned in the first main scanning direction Y1. FIG. 11B is a schematic diagram in “second overprinting”, and the image to be printed is a rotated image B. FIG. An arrow shown in the vicinity of the carriage 60 is an arrow indicating a printing direction in “second overprinting”. As shown in FIG. 11B, the printing direction in the “second overprinting” is the Y2 direction that is the opposite of the Y1 direction in the main scanning direction Y. The Y2 direction coincides with the left L of the printer 10. Hereinafter, the Y2 direction is referred to as a second main scanning direction Y2. In “second overprinting”, the printer 10 according to the present embodiment performs printing only when the carriage 60 is scanned in the second main scanning direction Y2.

  As shown in FIG. 11B, the first ink head 40 and the second ink head 50 are rotated 180 degrees from the state of FIG. Therefore, among the second nozzles 51, the second nozzle 51ca that is disposed on the most upstream X1 side in the sub-scanning direction X in FIG. 11A is the most sub-scanning among the second nozzles 51 in FIG. It moves to the downstream X2 side in the direction X. Further, among the nozzle rows constituted by the second nozzles 51, the nozzle row 52C of the ink head 50C is arranged closest to the second main scanning direction Y2 side in FIG. 11A, but FIG. In b), it is moved most to the first main scanning direction Y1 side. Accordingly, the second nozzle 51ca is also moved most to the first main scanning direction Y1 side among the second nozzles 51. That is, the second nozzle 51ca is the most upstream of the second nozzle 51 from the position of the most upstream X1 side in the sub-scanning direction X and the most second main scanning direction Y2 side. It has been moved to the position on the one main scanning direction Y1 side.

  As described above, when the first ink head 40 and the second ink head 50 are rotated from the “first position” to the “second position”, the arrangement of the nozzle rows and the arrangement of the nozzles in the nozzle rows are both reversed. To do. Specifically, at the “first position”, the nozzle rows are arranged in the order of 42, 52C, 52M, 52Y, and 52K from the second main scanning direction Y2 side. The two main scanning directions Y2 are arranged in the order of 52K, 52Y, 52M, 52C, and 42. For example, in the nozzle row 52C, the nozzles in the nozzle row are arranged in the order of 51ca to 51cj from the upstream X1 side in the sub-scanning direction X in the “first position”. They are arranged in the order of 51cj to 51ca from the upstream X1 side in the scanning direction X. As described above, when the holder 70 is rotated, the relative positional relationship between the printer main body 10a and each nozzle changes.

  However, according to the printer 10 according to the present embodiment, the relative positional relationship between the image and each nozzle is maintained by converting the image A into the rotated image B. For example, looking at the corner A1 of the image A, A1 is located at the upper left corner of the image. Further, the second nozzle 51 ca is located at the upper left in the second nozzle 51 of the second ink head 50. On the other hand, looking at the state at the “second position” shown in FIG. 11B, the corner corresponding to A1 in the rotated image B is B1. B1 is located at the lowermost right of the rotated image B. Further, the second nozzle 51 ca is located at the lowermost right in the second nozzle 51 of the second ink head 50. Thus, by converting the print image into a rotated image, even if the ink head rotates, the relative positional relationship between the image and the ink head is maintained.

  Further, in the printer 10 according to the present embodiment, the print control unit 120 changes the print direction between “first overlap printing” and “second overlap printing”, whereby the print direction and the arrangement of the ink heads are changed. The relative positional relationship is maintained. As shown in FIG. 11A, when the carriage 60 approaches the image A while printing, the ink head closest to the corner A1 of the image A is the ink head 50K. The traveling direction of the carriage 60 is a direction toward the first main scanning direction Y1. In FIG. 11B, the printing direction is changed to the direction toward the second main scanning direction Y2. However, even in the state of FIG. 11B, when the carriage 60 approaches the rotating image B while printing, the ink head closest to the corner B1 of the rotating image B is the ink head 50K. As described above, in the printer 10 according to the present embodiment, the print direction and the alignment of the ink heads are relatively changed by changing the print direction between the case of “first overlap printing” and the case of “second overlap printing”. The positional relationship is maintained.

  As described above, according to the printer 10 according to the present embodiment, the image direction and the printing direction are reversed in accordance with the rotation of the ink head. Therefore, the same image can be printed in the other mode based on the image data created for one of the “first overlap printing” and “second overlap printing”.

  Also, the arrangement of process color inks is important for print image quality. That is, for example, in the “first overlap printing”, when the second ink head 50 is arranged in the order of 50K, 50Y, 50M, and 50C from the first main scanning direction Y1, the ink head is rotated to be 50C and 50M. If the arrangement is changed in the order of 50Y, 50K, the color of the finished print changes. This is because the process color ink ejection order is reversed. However, in the printer 10 according to the present embodiment, the printing direction changes according to the rotation position of the ink head. Therefore, in the printer 10 according to the present embodiment, the arrangement order of the ink heads with respect to the printing direction does not change, and therefore the printing color does not change.

  The preferred embodiments of the present invention have been described above. However, the above-described embodiments are merely examples, and the present invention can be implemented in various other forms.

  For example, when the holder 70 is in the “first position” or the “second position”, the third printing control unit 123 moves the carriage 60 in the main scanning direction Y while moving the first protrusion of the first nozzle 41. Ink is ejected from a portion other than the portion 41a (ie, the first overlapping portion 41b), and ink is ejected from a portion other than the second protruding portion 51a (ie, the second overlapping portion 51b) of the second nozzle 51. Thus, the printing layer may be formed on the recording medium. That is, the printer 10 according to the present invention may be configured to perform one-layer printing using the nozzles belonging to the first overlapping portion 41b and the second overlapping portion 51b. According to the single-layer printing, the ink ejected from the first ink head 40 is treated as an ink that forms an image, similarly to the ink ejected from the second ink head 50. Therefore, the single-layer printing is a printing mode in which the print image quality differs between “normal printing” and “overlapping printing”.

  In the above-described embodiment, the first ink head 40 and the second ink head 50 are provided in the holder 70 so as to be partially shifted in the nozzle row direction N. However, the first ink head 40 and the second ink head 50 may be provided so as to be completely displaced in the nozzle row direction N, for example. The term “completely displaced” means that all of the first nozzles 41 are located in the N1 direction with respect to the second nozzles 51. In the above embodiment, the first use nozzle 41d coincides with the entire first nozzle 41. Further, the second use nozzle 51d coincides with the entire second nozzle 51. The first print control unit 121 according to the above embodiment forms the print layer of the special color ink on the recording medium 5 with the special color ink ejected from the first nozzle 41 when the holder 70 is in the “first position”. The recording medium 5 is moved from the upstream X1 side to the downstream X2 side in the sub-scanning direction X, and then the process color ink print layer is ejected from the second color nozzle 51 on the print layer by the special color ink. Form. On the other hand, when the holder 70 is in the “second position”, the second print control unit 122 according to the above embodiment uses the process color ink ejected from the second nozzle 51 to print the process color ink on the recording medium 5. After the recording medium 5 is formed, the recording medium 5 is moved from the upstream X1 side to the downstream X2 side in the sub-scanning direction X, and then the spot color ink is ejected from the first nozzle 41 on the print layer by the process color ink. The printing layer is formed. Also in the above embodiment, the carriage 60 can be prevented from being enlarged while corresponding to both “first overprint” and “second overprint” as in the first embodiment.

  The printer 10 according to the above-described embodiment includes a mode selection unit, and the rotation position of the holder 70 is automatically switched according to the print mode. However, the printer 10 does not have to include the mode selection unit, and may be configured to manually switch the rotation position of the holder 70. For example, the printer 10 may include an input unit in the control device 100, and the rotation control unit 130 may be set to move the holder 70 to a position input to the input unit. The input unit is a member for an operator to input the position of the holder 70. The input unit may be displayed and operated on a display device such as a computer, for example. Or you may come to operate with a button. The configuration of the input unit is not limited. The printer 10 may include both a mode selection unit and an input unit. In this case, the printer 10 is a printer that can perform printing both automatically and semi-automatically.

  In the above-described embodiment, the carriage 60 is provided with the rotation driving device 82. However, the printer 10 does not have to include the rotation driving device 82. For example, the holder 70 may be configured to be manually rotated by an operator. Once the rotational position of the holder 70 is set, the holder 70 may be rotated manually as described above for applications that hardly change. In that case, the carriage 60 preferably includes a member for positioning and fixing the holder 70.

  In the above-described embodiment, the first ink head 40 and the second ink head 50 are configured to change positions by rotating the holder 70 about the rotation shaft 81. However, the method of changing the positions of the first ink head and the second ink head is not limited to the above method. For example, the position of the first ink head and the second ink head may be changed by removing the holder 70 from the carriage 60 and reattaching the holder 70 with the direction reversed. Further, the carriage 60 and the holder 70 are not necessarily arranged above and below, and may be arranged, for example, at the front and back.

  In the second embodiment described above, the same image is printed in “first overprint” and “second overprint”. However, for example, when the recording medium 5 is a transparent sheet or the like and the first ink is a special color ink such as white ink, the image by the “second overprinting” can be seen from the back side of the printing surface. It is often assumed. Therefore, the printer according to the present invention may be set so that a reverse image of the image by “first overprinting” is printed in “second overprinting”. The reverse image is a normal image when viewed from the back side of the printing surface.

  In the above-described embodiment, the sub-scanning direction moving device 30 includes a mechanism for transporting the recording medium 5 toward the front F direction of the printer 10. However, the sub-scanning direction moving device 30 is not limited to the one provided with the above mechanism. The sub-scanning direction moving device 30 may be a device that moves the recording medium 5 and the carriage 60 relative to each other in the sub-scanning direction X. For example, the sub-scanning direction moving device 30 may include a mechanism that moves the carriage 60 in the sub-scanning direction X. . Further, the sub-scanning direction moving device 30 is not limited to the one that conveys the recording medium 5 only from the upstream X1 side to the downstream X2 side in the sub-scanning direction X. The sub-scanning direction moving device 30 moves the recording medium 5 as necessary on the downstream X2 side in the sub-scanning direction X as seen in, for example, a printer equipped with a cutting mechanism that cuts the periphery of the image after printing the image. To the upstream X1 side.

5 Recording medium 10 Printer (inkjet printer)
20 Main scanning direction moving device 30 Sub scanning direction moving device 40 First ink head 41 First nozzle 50 Second ink head 51 Second nozzle 60 Carriage 70 Holder 80 Rotation mechanism 82 Rotation drive device 100 Control device 110 Mode selection unit 120 Printing Control unit 121 First print control unit 122 Second print control unit 123 Third print control unit 130 Rotation control unit 140 Image data processing unit 141 Image data reception unit 142 Rotation image data generation unit

Claims (14)

A first ink head having a plurality of first nozzles arranged in one direction and discharging the first ink from the first nozzle toward the recording medium;
A second ink head having a plurality of second nozzles arranged in one direction and discharging the second ink from the second nozzle toward the recording medium;
A carriage movable in the main scanning direction;
A holder provided on the carriage and holding the first ink head and the second ink head;
A main scanning direction moving device for moving the carriage in the main scanning direction;
A sub-scanning direction moving device that moves the recording medium relative to the carriage from upstream to downstream in the sub-scanning direction perpendicular to the main scanning direction;
A control device for controlling the first ink head, the second ink head, the main scanning direction moving device, and the sub-scanning direction moving device;
In the carriage, the holder includes the plurality of first nozzles arranged in the sub-scanning direction, the plurality of second nozzles arranged in the sub-scanning direction, and a part of the plurality of first nozzles arranged in the first scanning direction. The first ink head and the first ink head so as to be positioned upstream of the two nozzles in the sub-scanning direction and a part of the plurality of second nozzles positioned downstream of the first nozzle in the sub-scanning direction; A plurality of positions including a first position where the second ink head is held, and a second position obtained by rotating the first position 180 degrees around a rotation axis perpendicular to the main scanning direction and the sub-scanning direction. Switchable to the position of
The controller is
When the holder is in the first position, the recording is performed by discharging the first ink from the part and the other part of the plurality of first nozzles while moving the carriage in the main scanning direction. A first printing layer is formed on the medium, and then the recording medium is moved from the upstream side to the downstream side in the sub-scanning direction with respect to the carriage, and then the carriage is moved in the main scanning direction. By discharging the second ink from the part of the plurality of second nozzles and the other part of the first nozzle located downstream of the other part of the first scanning direction, the first ink is discharged. A first print control unit that forms a second print layer on the print layer;
When the holder is in the second position, the recording is performed by discharging the second ink from the part and the other part of the plurality of second nozzles while moving the carriage in the main scanning direction. The second print layer is formed on the medium, and then the recording medium is moved from the upstream side to the downstream side in the sub-scanning direction with respect to the carriage, and then the carriage is moved in the main scanning direction. The first ink is ejected from the part of the plurality of first nozzles and the other part of the second nozzle located downstream of the other part of the second scanning direction. A second print control unit that forms the first print layer on the two print layers,
Inkjet printer. The holder is configured to be rotatable around a rotation axis perpendicular to the main scanning direction and the sub-scanning direction.
The inkjet printer according to claim 1. A rotation drive device for rotating the holder;
The inkjet printer according to claim 2. The second ink head includes a first color ink head that ejects a second ink of a first color, and a second color ink head that ejects a second ink of a second color,
The first color ink head is disposed on one side of the main scanning direction with respect to the second color ink head,
The first print control unit is configured to move the carriage from the one side to the other side in the main scanning direction when the second ink head discharges the second ink.
The second print control unit is configured to move the carriage from the other in the main scanning direction to the one when the second ink head ejects the second ink.
The inkjet printer as described in any one of Claims 1-3. The controller is
An image data receiving unit for receiving image data for printing an image formed by at least the second ink of the first color and the second ink of the second color;
A rotated image data generating unit that generates image data of a rotated image obtained by rotating the image 180 degrees around a rotation axis perpendicular to the image from the image data;
The first print control unit is configured to control the second ink head based on the image data,
The second print control unit is configured to control the second ink head based on image data of the rotated image.
The inkjet printer according to claim 4. The part of the plurality of first nozzles is 50% or more of the whole of the plurality of first nozzles.
The ink jet printer according to claim 1. The part of the plurality of first nozzles is less than 50% of the whole of the plurality of first nozzles;
The ink jet printer according to claim 1. When the holder is in the first position or the second position, the control device moves the carriage in the main scanning direction from a portion other than the part of the plurality of first nozzles. A third print control unit configured to form a print layer on the recording medium by ejecting the first ink and ejecting the second ink from a portion other than the part of the plurality of second nozzles; ing,
The ink jet printer according to claim 1. The first ink is a spot color ink;
The second ink is a process color ink.
The ink jet printer according to claim 1. A first ink head having a plurality of first nozzles arranged in one direction and discharging the first ink from the first nozzle toward the recording medium;
A second ink head having a plurality of second nozzles arranged in one direction and discharging the second ink from the second nozzle toward the recording medium;
A carriage movable in the main scanning direction;
A holder provided on the carriage and holding the first ink head and the second ink head;
A main scanning direction moving device for moving the carriage in the main scanning direction;
A sub-scanning direction moving device that moves the recording medium relative to the carriage from upstream to downstream in the sub-scanning direction perpendicular to the main scanning direction;
A control device for controlling the first ink head, the second ink head, the main scanning direction moving device, and the sub-scanning direction moving device;
In the carriage, the holder includes the plurality of first nozzles arranged in the sub-scanning direction, the plurality of second nozzles arranged in the sub-scanning direction, and the plurality of first nozzles from the second nozzle. The first position at which the first ink head and the second ink head are held so as to be positioned upstream of the sub-scanning direction, and the first position with respect to the main scanning direction and the sub-scanning direction It is configured to be switchable to a plurality of positions including a second position rotated 180 degrees around a vertical rotation axis,
The controller is
When the holder is in the first position, a first print layer is formed on the recording medium by ejecting the first ink from the plurality of first nozzles while moving the carriage in the main scanning direction. Then, after the recording medium is moved from the upstream side in the sub-scanning direction to the downstream side with respect to the carriage, the second nozzle is moved from the plurality of second nozzles while the carriage is moved in the main scanning direction. A first print control unit that forms a second print layer on the first print layer by ejecting ink;
When the holder is in the second position, the second ink is ejected from the plurality of second nozzles while the carriage is moved in the main scanning direction, whereby the second print layer is formed on the recording medium. And then moving the recording medium from the upstream side in the sub-scanning direction to the downstream side with respect to the carriage, and then moving the carriage in the main scanning direction from the plurality of first nozzles. A second print control unit that forms the first print layer on the second print layer by discharging one ink;
Inkjet printer. The holder is configured to be rotatable around a rotation axis perpendicular to the main scanning direction and the sub-scanning direction.
The inkjet printer according to claim 10. A rotation drive device for rotating the holder;
The inkjet printer according to claim 11. The second ink head includes a first color ink head that ejects a second ink of a first color, and a second color ink head that ejects a second ink of a second color,
The first color ink head is disposed on one side of the main scanning direction with respect to the second color ink head,
The first print control unit is configured to move the carriage from the one side to the other side in the main scanning direction when the second ink head discharges the second ink.
The second print control unit is configured to move the carriage from the other in the main scanning direction to the one when the second ink head ejects the second ink.
The inkjet printer according to any one of claims 10 to 12. The controller is
An image data receiving unit for receiving image data for printing an image formed by at least the second ink of the first color and the second ink of the second color;
A rotated image data generating unit that generates image data of a rotated image obtained by rotating the image 180 degrees around a rotation axis perpendicular to the image from the image data;
The first print control unit is configured to control the second ink head based on the image data,
The second print control unit is configured to control the second ink head based on image data of the rotated image.
The inkjet printer according to claim 13.

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