JP5617588B2 - Printing apparatus and printing method - Google Patents

Description

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

  It is known to print a background image with a background color such as white and a color image on a transparent medium (see Patent Document 1). When a color image is viewed from the printing surface side of the medium, first, the background image is printed on the medium, and the color image is printed on the background image. This printing method is called “surface printing”. Conversely, when a color image is viewed from the back side of a transparent medium, the color image is first printed on the medium, and the background image is printed on the color image. This printing method is called “back printing”.

JP 2009-113284 A

  In Patent Document 1, the functions of the two heads are clearly separated. One head is a head (white head) for printing a background image, and the other head is a head (color head) for printing a color image. For this reason, the arrangement position of one head only switches to either the upstream side or the downstream side in the transport direction with respect to the other head.

  An object of the present invention is to improve the degree of freedom of the arrangement of the two heads by enabling the two heads to eject the same ink, thereby enabling various printing.

A main invention for achieving the above object includes a transport mechanism for transporting a medium in a first direction and a plurality of nozzle arrays composed of a plurality of nozzles arranged in the first direction, and can eject a plurality of types of ink. A first head, a plurality of nozzle arrays each including a plurality of nozzles arranged in the first direction, a second head capable of ejecting a plurality of types of ink, and a second direction intersecting the first direction. A carriage for moving the first head and the second head along the first head and the second head, the first head and the second head are arranged in parallel in the second direction, and the first head and the second head are arranged in the second direction. A head moving mechanism for changing a positional relationship between the first head and the second head in the first direction so as to shift the positions at different positions in one direction; and the head movement mechanism from the first head and the second head. A controller for controlling the discharge of ink, and in the case of the parallel arrangement, the controller discharges the same type of ink from the first head and the second head, respectively. In the shift arrangement, a different type of ink is ejected from the first head and the second head, respectively.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

1 is an overall configuration block diagram of a printer. 2A is a schematic cross-sectional view of the printer 1, and FIG. 2B is a schematic top view of the printer 1. 3A and 3B are explanatory views of the lower surface of the carriage. 4A to 4D are explanatory diagrams of printing in a parallel arrangement. FIG. 5A is an explanatory diagram of the positional relationship between two black nozzle rows in the high resolution mode. FIG. 5B is an explanatory diagram of a positional relationship between two black nozzle rows in the speed priority mode. FIG. 6A is an explanatory diagram of dot formation by the black nozzle row in the high resolution mode. FIG. 6B is an explanatory diagram showing how dots are formed by the black nozzle row in the speed priority mode. FIG. 7A to FIG. 7D are explanatory diagrams of surface printing in a shift arrangement. 8A to 8D are explanatory diagrams of front printing in the shift arrangement. 9A and 9B are explanatory views of the lower surface of the carriage according to the second embodiment. 10A to 10D are explanatory diagrams of printing in a parallel arrangement in the second embodiment. 11A to 11B are explanatory diagrams of printing with a fixing material in a shift arrangement. 12A to 12B are explanatory diagrams of glossy printing in the shift arrangement. 13A and 13B are explanatory views of the lower surface of the carriage according to the third embodiment. 14A to 14D are explanatory diagrams of printing in the parallel arrangement in the third embodiment. 15A to 15G are explanatory diagrams of front-surface gloss printing (clear ink thick coating). 16A to 16E are explanatory views of front gloss printing (uniform coating). FIGS. 17A to 17G are explanatory diagrams of front-surface gloss printing (white ink thick coating). It is explanatory drawing of the relationship between arrangement | positioning about 1st Embodiment-3rd Embodiment, and the kind of ink to discharge.

  At least the following matters will become clear from the description of the present specification and the accompanying drawings.

A plurality of nozzle rows composed of a plurality of nozzles arranged in the first direction, and a plurality of nozzle rows composed of a first head capable of discharging a plurality of types of ink and a plurality of nozzles arranged in the first direction are provided. A second head capable of ejecting a plurality of types of ink, a carriage for moving the first head and the second head along a second direction intersecting the first direction, the first head, and the first head The two heads are arranged in parallel in the second direction, and the first head and the second head are arranged so as to shift the first head and the second head to different positions in the first direction. A printing apparatus comprising: a head moving mechanism that changes a positional relationship in one direction; and a controller that controls ejection of the ink from the first head and the second head. In the case of the parallel arrangement, the same type of ink is ejected from the first head and the second head, and in the case of the shift arrangement, from the first head and the second head. Thus, it becomes clear that the printing apparatus is characterized by ejecting different types of ink.
According to such a printing apparatus, various types of printing are possible.

  In the parallel arrangement, the controller preferably forms a dot row by the nozzles of the second head between the dot rows formed by the nozzles of the first head. Thereby, it is possible to print at a high resolution.

  In the parallel arrangement, it is preferable that the controller forms dots by the nozzles of the second head between dots arranged in the second direction formed by the nozzles of the first head. Thereby, printing can be performed at high speed.

  The ink ejected from the first head and the second head is ink that cures when irradiated with light, and the carriage is provided with an irradiation unit that irradiates the light. In the case of the parallel arrangement, it is desirable to irradiate the light from an area where the position in the first direction is the same as that of the print area, and it is also preferable to irradiate the light from an area where the position of the print area and the first direction is different . Thereby, it is possible to irradiate light twice after forming an image.

  The irradiation unit is provided so as to sandwich the first head and the second head from the second direction, and the irradiation unit has a position in the print area and the first direction in the parallel arrangement. When irradiating light from different areas, it is desirable to irradiate light upstream of the print area in the direction in which the carriage moves. Thereby, it becomes difficult to produce a level | step difference in the joint of an image.

  In the case of the shift arrangement, the controller preferably forms an image with the first head on an image formed with the second head. Thereby, for example, surface printing or back printing can be performed.

A plurality of nozzle rows composed of a plurality of nozzles arranged in the first direction, and a plurality of nozzle rows composed of a first head capable of discharging a plurality of types of ink and a plurality of nozzles arranged in the first direction are provided. A second head capable of ejecting a plurality of types of ink, a carriage for moving the first head and the second head along a second direction intersecting the first direction, the first head, and the first head The two heads are arranged in parallel in the second direction, and the first head and the second head are arranged so as to shift the first head and the second head to different positions in the first direction. And a head moving mechanism that changes a positional relationship in one direction. In the case of the parallel arrangement, a printing method of the same type of ink from each of the first head and the second head. While ejecting the case of the shift arrangement, from the first head and the second head, the printing method characterized by discharging a different kind of ink respectively is apparent.
According to such a printing method, various printing is possible.

=== First Embodiment ===
<Overall configuration>
FIG. 1 is a block diagram of the overall configuration of the printer 1, FIG. 2A is a schematic cross-sectional view of the printer 1, and FIG. 2B is a schematic top view of the printer 1. Hereinafter, an embodiment will be described with an example of a printing system in which the printing apparatus is an inkjet printer (printer 1) and the printer 1 and the computer 90 are connected.

  The controller 10 is a control unit for controlling the printer 1. The interface unit 11 is for transmitting and receiving data between the computer 90 and the printer 1. The CPU 12 is an arithmetic processing unit for controlling the entire printer 1. The memory 13 is for securing an area for storing a program of the CPU 12, a work area, and the like. The CPU 12 controls each unit by the unit control circuit 14. The detector group 50 monitors the situation in the printer 1, and the controller 10 controls each unit based on the detection result.

  The transport unit 20 transports the medium S from the upstream side to the downstream side in a direction (transport direction) in which the medium S (roll paper or the like) continues. The roll-shaped medium S before printing is supplied to the printing area by the conveyance roller 21 driven by a motor, and then the printed medium S is wound into a roll shape by a winding mechanism. Note that the medium S can be held at a predetermined position by vacuum suction of the medium located in the print area during printing.

  The carriage unit 30 reciprocates the head in the paper width direction. The carriage unit 30 includes a carriage 31 on which the head is mounted and a carriage movement mechanism 32 for reciprocating the carriage.

  The head unit 40 has a head provided on the carriage 31. A plurality of nozzles that are ink discharge portions are provided on the lower surface of the head. In this embodiment, UV ink is ejected from the nozzle. The UV ink is an ink having a property of curing when irradiated with ultraviolet light. In the present embodiment, the head unit 40 includes a head moving mechanism 42 for changing the position of the head in the transport direction.

The irradiation unit 60 is for irradiating the UV ink discharged onto the medium with ultraviolet light. The irradiation unit 60 of the present embodiment includes a provisional curing irradiation unit 61 and a main curing irradiation unit 62.
The provisional curing irradiation unit 61 is provided on the carriage 31 and is movable together with the head. The pre-curing irradiation unit 61 irradiates the UV light with such an intensity that the surface of the UV ink is cured (temporarily cured) so that the UV inks that have landed on the medium do not spread. For example, LED (light emitting diode) etc. are employ | adopted as the irradiation part 61 for temporary hardening. The controller 10 irradiates the ultraviolet light from the temporary curing irradiation unit 61 while moving the carriage 31 to temporarily cure the UV ink on the printing region.
The main curing irradiation unit 62 is provided on the downstream side in the X direction of the printing region, and can irradiate ultraviolet light over the width of the medium. The main curing irradiation unit 62 irradiates UV light having an intensity capable of main curing (completely solidifying) the UV ink on the medium. For example, a UV lamp or the like is employed as the main curing irradiation unit 62. The controller 10 irradiates the ultraviolet light from the main curing irradiation unit 62 while conveying the medium, and cures the image formed by the UV ink.

  When performing printing, the printer 1 alternately repeats an operation (pass) for moving the carriage 31 in the moving direction and a conveying operation. In each pass, the printer 1 ejects ink from the head to form an image on the medium, and irradiates the ultraviolet light from the temporary curing irradiation unit 61 to temporarily cure the image. By repeating the pass and the conveying operation in this manner, it is possible to form an image by joining the medium.

  By repeating the pass and the conveying operation, the image formed in the printing region is gradually conveyed toward the main curing irradiation unit 62. When the image is conveyed to a position facing the main curing irradiation unit 62, ultraviolet light is irradiated from the main curing irradiation unit 62 and the image is main cured.

<Configuration of the underside of the carriage>
3A and 3B are explanatory views of the lower surface of the carriage. In the following description, the head arrangement in FIG. 3A is referred to as “parallel arrangement”, and the head arrangement in FIG. 3B is referred to as “shift arrangement”. First, the configuration of the lower surface of the carriage will be described based on the parallel arrangement of FIG. 3A.

  Two heads (first head 41 </ b> A and second head 42 </ b> B) are provided on the lower surface of the carriage 31. The two heads are provided at different positions in the carriage movement direction. Further, two temporary curing irradiation sections 61 are provided on the carriage 31 so as to sandwich these two heads from the moving direction.

  Each of the two heads includes five nozzle rows. The five nozzle rows are a black nozzle row (K) for discharging black ink, a cyan nozzle row (C) for discharging cyan ink, and a magenta nozzle row (M) for discharging magenta ink. And a yellow nozzle row (Y) for discharging yellow ink and a white nozzle row (W) for discharging white ink. The black nozzle row, cyan nozzle row, magenta nozzle row, and yellow nozzle row are nozzle rows (color nozzle row group) for forming a color image. The white nozzle row is a nozzle row for forming a background image.

  Each nozzle row is composed of 180 nozzles. The 180 nozzles in each nozzle row are arranged along the transport direction at a predetermined nozzle pitch, and are arranged at an interval of 1/180 inch in this embodiment. For this reason, each nozzle row can form dots in a printing range having a width of 1 inch (L in the drawing) every time the carriage 31 moves once in the movement direction. In the present embodiment, the print range of the first head and the print range of the second head in the parallel arrangement almost overlap each other.

  The two pre-curing irradiation units 61 can irradiate the irradiation range with a width of 2 inches (corresponding to 2 × L) along the conveying direction with ultraviolet light. In addition, when two heads are positioned side by side as in a parallel arrangement, the two heads are positioned on the upstream side in the transport direction in the irradiation range of the pre-curing irradiation unit 61. Thereby, the pre-curing irradiation unit 61 can irradiate the ink discharged from the heads arranged in parallel with the ultraviolet light at least twice.

  Next, the configuration of the lower surface of the carriage will be described using FIG. 3B as well.

  The first head 41A is movable along the transport direction. The head moving mechanism 42 moves the first head 41 </ b> A along the transport direction in response to an instruction from the controller 10. When the first head 41A moves from the parallel arrangement state (see FIG. 3A) by the distance L to the downstream side in the transport direction, the shift arrangement state (see FIG. 3B) is obtained. The second head 41B is fixed to the lower surface of the carriage 31.

  In the present embodiment, the distance in the conveyance direction between the position of the first head 41A arranged in parallel and the position of the first head 41A arranged in shift is the conveyance operation during printing (conveyance performed between passes). It is far from the transport amount of (operation). Therefore, in this embodiment, in the shift arrangement state, the conveyance direction between the position of the nozzle on the most upstream side in the conveyance direction of the first head 41A and the position of the nozzle on the most upstream side in the conveyance direction of the second head 41B. This distance is longer than the transport amount of the transport operation during printing. As described above, in the shift arrangement, the two heads are arranged so as to be shifted from the carrying amount of the carrying operation. Accordingly, when attention is paid to the print area having a width corresponding to the carry amount, the nozzle row of one head is placed in the print area. It is necessary to perform at least one conveyance operation after the image is formed and before the nozzle row of the other head forms an image in the same print area.

<Printing in parallel layout>
In the parallel arrangement, the print ranges of the two heads almost overlap. If you try to print the background image and the color image (surface printing or back printing) in such a state, it takes time to print (because the background image and the color image cannot be printed in the same pass). .

  For this reason, when only a color image is printed, printing by parallel arrangement is performed. The controller 10 arranges two heads in parallel when only a color image is printed using the color nozzle row group (when a background image is not formed). When printing is performed in a parallel arrangement, the color nozzle group is used for both of the two heads, and the white nozzle row is not used.

Printing Operation FIGS. 4A to 4D are explanatory diagrams of printing in a parallel arrangement. In the drawing, the nozzle row for ejecting ink is shown in black, and the region of the pre-curing irradiation section that irradiates ultraviolet light is blacked out.

  First, as shown in FIG. 4A, the controller 10 moves the carriage 31 in the movement direction, and supplies color ink from each nozzle row (K, C, M, Y) of each color nozzle row group of the two heads. Discharge. As a result, a color image having a width L (1 inch) in the conveyance direction is formed on the medium. The operation of moving the carriage 31 in the movement direction may be referred to as “pass”. In addition, the first pass may be referred to as “pass 1” (that is, FIG. 4A is a diagram showing a state of pass 1).

  In pass 1, the controller 10 irradiates ultraviolet light from the pre-curing irradiation unit 61 on the upstream side in the moving direction of the carriage 31 (left side in FIG. 4A). As a result, the color ink immediately after landing on the medium is irradiated with ultraviolet light, the surface of the ink is cured (temporarily cured), and ink bleeding is suppressed. Since it is not necessary to irradiate the area where no color image is formed with ultraviolet light, the provisional curing irradiating unit 61 irradiates the ultraviolet light from an area where the position in the transport direction is the same as that of the color nozzle array group. No ultraviolet light is irradiated from the region downstream in the transport direction (ultraviolet light is irradiated from the upper half region of the temporary curing irradiation unit 61 on the left side of FIG. 4A).

  Next, as illustrated in FIG. 4B, the controller 10 transports the medium in the transport direction. The carry amount at this time is L (1 inch). As a result, the area in which the color image is formed in FIG. 4A is positioned downstream of the printing area in the transport direction, and the unprinted portion of the medium is supplied to the printing area.

  Then, as illustrated in FIG. 4C, the controller 10 causes the pass 2 (second pass) to be performed. In pass 2, the controller 10 moves the carriage 31 in the movement direction and ejects color ink from each nozzle row (K, C, M, Y) of each color nozzle row group of the two heads. As a result, a color image having a width L (1 inch) in the conveyance direction is formed on the medium.

  Also in pass 2, the controller 10 irradiates the ultraviolet light from the temporary curing irradiation unit 61 on the upstream side in the movement direction of the carriage 31. However, since the moving direction of the head in pass 2 is opposite to the moving direction in pass 1, ultraviolet light is irradiated from the provisional curing irradiation unit 61 on the right side in FIG. 4C.

In pass 2, the controller 10 again irradiates the color image formed in pass 1 (a color image that has already been irradiated with the pre-curing ultraviolet light once) with the pre-curing ultraviolet light. It is possible. In this case, the pre-curing irradiation unit 61 also irradiates ultraviolet light from a region (lower region in FIG. 4C) located downstream in the transport direction from the color nozzle row group.
When irradiating ultraviolet light to an image located downstream in the transport direction from the color nozzle row group, the temporary curing irradiation unit 61 on the downstream side in the movement direction of the carriage 31 (left side in FIG. 4C) irradiates the ultraviolet light. It is more preferable to irradiate ultraviolet light from the pre-curing irradiation unit 61 on the upstream side in the moving direction of the carriage 31 (right side in FIG. 4C). If the temporary curing irradiation unit 61 on the downstream side in the movement direction of the carriage 31 (left side in FIG. 4C) irradiates ultraviolet light in pass 2, it is formed in pass 1 immediately before the color image is formed in pass 2. This is because the number of times of irradiation (2 times) of the ultraviolet light to the color image is increased, and a step is likely to occur at the joint between the pass 1 and pass 2 color images. On the other hand, if ultraviolet light is irradiated from the temporary curing irradiation unit 61 on the upstream side in the movement direction of the carriage 31 (right side in FIG. 4C) as shown in FIG. Since the number of times of irradiation of the ultraviolet light to the color image formed in pass 1 is one, there is an effect that a step is hardly generated at the joint between the color images in pass 1 and pass 2.
However, if it is necessary to irradiate the color image formed in pass 1 with ultraviolet light as much as possible in the preliminary curing stage, both of the two preliminary curing irradiation sections 61 are downstream in the transport direction from the color nozzle row group. You may irradiate an ultraviolet light also from the area | region located in the side.

  After pass 2, as shown in FIG. 4D, the controller 10 transports the medium in the transport direction. The carry amount at this time is L (1 inch). As a result, the area where the color image is formed in FIG. 4C is positioned downstream of the print area in the transport direction, and the unprinted portion of the medium is supplied to the print area.

  Then, after FIG. 4D, the controller 10 alternately repeats the operation (pass) for moving the carriage 31 in the movement direction and the conveyance operation. In each pass, the controller 10 discharges color ink from each nozzle row (K, C, M, Y) of the color nozzle row group to form a color image on the medium, and from the pre-curing irradiation unit 61. Irradiate ultraviolet light to temporarily cure the color image. By repeating the pass and the transport operation in this manner, a color image can be formed on the medium by joining them.

  When printing a color image in a parallel arrangement, there are two printing modes, a high resolution mode and a speed priority mode.

High Resolution Mode FIG. 5A is an explanatory diagram of the positional relationship between the two black nozzle rows in the high resolution mode. Here, the black nozzle row is described, but the two nozzle rows of other colors are the same as the black nozzle row.

  In the high resolution mode, the print ranges of the two nozzle rows almost overlap. However, the positions of the two nozzle rows in the transport direction are shifted by half the nozzle pitch. For this reason, the nozzle of one nozzle row is located between the two nozzles of the other nozzle row in the transport direction. In the high resolution mode, the controller 10 moves the first head 41A by the head moving mechanism 42 so that the two nozzle rows are arranged in this way.

  FIG. 6A is an explanatory diagram of dot formation by the black nozzle row in the high resolution mode. On the left side of the drawing, the nozzles of the black nozzle row of the first head 41A are indicated by black circles, and the nozzles of the black nozzle row of the second head 41B are indicated by white circles. Further, on the right side of the drawing, dots formed by the black nozzle row of the first head 41A are indicated by black circles, and dots formed by the black nozzle row of the second head 41B are indicated by white circles.

  In the high resolution mode, a dot row formed by the nozzles of the black nozzle row of the second head 41B is positioned between the dot rows formed by the nozzles of the black nozzle row of the first head 41A. As a result, it is possible to perform printing at a resolution of 1/360 inch which is finer than 1/180 inch which is the nozzle pitch.

Speed priority mode FIG. 5B is an explanatory diagram of the positional relationship between the two black nozzle rows in the speed priority mode. Even in the speed priority mode, the print ranges of the two nozzle rows overlap.

  In the speed priority mode, the two nozzle rows are located at the same position in the transport direction. For this reason, the nozzles of one nozzle row are located at the same position in the transport direction as the nozzles of the other nozzle row. In the speed priority mode, the controller 10 moves the first head 41A by the head moving mechanism 42 so that the two nozzle rows are arranged as described above.

  FIG. 6B is an explanatory diagram showing how dots are formed by the black nozzle row in the speed priority mode. In the speed priority mode, printing can be performed with a resolution of 1/180 inch, which is the nozzle pitch.

  In the speed priority mode, since two nozzles exist at the same position in the transport direction, a dot row arranged in the movement direction can be formed using the two nozzles. For this reason, when forming a dot row by arranging dots at an interval of 1/180 inch in the moving direction, the nozzles of one nozzle row form dots every other dot, and the nozzles of the other nozzle row Dots are formed to fill. In other words, dots are formed at intervals of 1/90 inch with any nozzle row. When forming a dot row by arranging dots at an interval of 1/180 inch in the moving direction, the nozzles of each nozzle row form dots at an interval of 1/90 inch.

  By the way, the time interval between the ejection of ink from the nozzle and the ejection of the next ink has a limit for shortening, and this limit time is T. In the above-described high resolution mode (FIG. 6A), since each nozzle forms dots arranged at intervals of 1/360 inch in the moving direction, the moving speed of the carriage moves by 1/360 inch during the limit time T. The speed is limited and cannot be faster. On the other hand, in the speed priority mode (FIG. 6B), each nozzle has only to be formed by arranging dots at intervals of 1/90 inch in the moving direction, and therefore the carriage 31 is moved by 1/90 inch during the limit time T. be able to. That is, if the limit times of FIG. 6A and FIG. 6B are the same, the carriage 31 can be moved about four times faster in the speed priority mode than in the high resolution mode.

<Printing with shift arrangement>
In the shift arrangement (see FIG. 3B), the print ranges of the two heads are different. When the background image and the color image are overlaid and printed (surface printing or reverse printing), the printing range of the background image and the printing range of the color image cannot be overlapped in the same pass. Therefore, the controller 10 shifts the two heads so that one head forms a background image and the other head forms a color image so that the print ranges of the images do not overlap. . And the controller 10 prints so that the other image may be superimposed after temporarily curing one image.

Front-print printing Front-print printing is printing in which a background image is formed on a medium and then a color image is formed on the background image.
FIG. 7A to FIG. 7D are explanatory diagrams of surface printing in a shift arrangement.

First, in pass 1, as shown in FIG. 7A, the controller 10 moves the carriage 31 in the moving direction and discharges white ink from the white nozzle row of the second head 41B. As a result, a white background image having a width in the transport direction of L (1 inch) is formed on the medium.
In pass 1, the controller 10 irradiates ultraviolet light from the pre-curing irradiation unit 61 on the upstream side in the moving direction of the carriage 31 (left side in FIG. 7A). As a result, the white ink immediately after landing on the medium is irradiated with ultraviolet light, and the surface of the ink is cured (temporarily cured). Thereby, even if the color ink is ejected on the white ink, the bleeding between the white ink and the color ink can be suppressed. Since it is not necessary to irradiate the region where the background image is not formed with the ultraviolet light, the temporary curing irradiation unit 61 irradiates the ultraviolet light from the region where the position of the second nozzle 41B in the transport direction is the same as the white nozzle row. The ultraviolet light is not irradiated from the region downstream in the transport direction (the ultraviolet light is irradiated from the upper half region of the temporary curing irradiation unit 61 on the left side of FIG. 7A).

  Next, as illustrated in FIG. 7B, the controller 10 transports the medium in the transport direction. The carry amount at this time is L (1 inch). As a result, the area where the background image is formed in FIG. 7A is located in the print area of the first head 41A in pass 2 (second pass), and the unprinted portion of the medium is in the second head 41B in pass 2. Supplied to the print area.

  Then, as illustrated in FIG. 7C, the controller 10 causes the pass 2 to be performed. Also in pass 2, the controller 10 moves the carriage 31 in the movement direction and discharges white ink from the white nozzle row of the second head 41B. As a result, a white background image having a width in the transport direction of L (1 inch) is formed on the medium.

  In pass 2, as shown in FIG. 7C, the controller 10 ejects color ink from each nozzle row (K, C, M, Y) of the color nozzle row group of the first head 41A. As a result, a color image having a width L (1 inch) in the conveyance direction is formed on the medium on the background image formed in pass 1.

  Further, in pass 2, the controller 10 irradiates ultraviolet light from the pre-curing irradiation unit 61 on the upstream side in the movement direction of the carriage 31 (right side in FIG. 7C). In pass 2, the pre-curing irradiation unit 61 irradiates not only the background image formed by the white nozzle array of the second head 41B but also the color image formed by the color nozzle array group of the first head 41A. Therefore, ultraviolet light is irradiated from all areas. In other words, the pre-curing irradiation unit 61 irradiates the ultraviolet light from an area where the printing area of the two heads and the position in the transport direction are the same.

  In pass 2, the temporary curing irradiation unit 61 on the downstream side in the moving direction of the carriage 31 (left side in FIG. 4C) also emits ultraviolet light from the region on the downstream side in the transport direction (lower half region in FIG. 4C). It may be irradiated. In this way, the background image can be sufficiently temporarily cured before the color image is formed, and bleeding between the color ink and the white ink can be particularly suppressed. In addition, even if there is a step at the joint between the background images of pass 1 and pass 2, it is difficult to stand out because it is a background image.

  After pass 2, as shown in FIG. 7D, the controller 10 transports the medium in the transport direction. The carry amount at this time is L (1 inch). Accordingly, the area where the background image is formed in FIG. 7C is positioned in the print area of the first head 41A in pass 3, and the unprinted portion of the medium is supplied to the print area of the second head 41B in pass 3. .

  Then, after FIG. 7D, the controller 10 alternately repeats the operation (pass) for moving the carriage 31 in the movement direction and the conveyance operation. In each pass, the controller 10 discharges white ink from the white nozzle row of the second head 41B, and performs color from each nozzle row (K, C, M, Y) of the color nozzle row group of the first head 41A. Ink is ejected. In other words, in each pass, the controller 10 forms a background image in the upstream half area of the printing area having a width in the transport direction of 2L, and forms a color image in the downstream half area. In each pass, the controller 10 irradiates ultraviolet light from the temporary curing irradiation unit 61 on the upstream side in the moving direction of the carriage 31 to temporarily cure the background image and the color image. By repeating such a pass and the transport operation of the transport amount of L, surface printing that prints a color image on the background image can be performed.

Backside printing Backside printing is printing in which a color image is formed on a medium and then a background image is formed on the color image. The reverse printing is mainly performed on a transparent medium, and the color image of the printed material by the reverse printing is seen through the transparent medium.

  8A to 8D are explanatory diagrams of front printing in the shift arrangement. Compared with the above-described surface printing (FIGS. 7A to 7D), the head for forming a color image and the head for forming a background image are reversed.

  The controller 10 alternately repeats the operation (pass) for moving the carriage 31 in the movement direction and the conveying operation. In each pass, the controller 10 ejects color ink from each nozzle row (K, C, M, Y) of the color nozzle row group of the second head 41B, and also performs white ink from the white nozzle row of the first head 41A. Ink is ejected. In each pass, the controller 10 irradiates ultraviolet light from the temporary curing irradiation unit 61 on the upstream side in the moving direction of the carriage 31 to temporarily cure the background image and the color image. By repeating the pass and the transport operation in this way, it is possible to perform reverse printing for printing a background image on a color image.

=== Second Embodiment ===
9A and 9B are explanatory views of the lower surface of the carriage according to the second embodiment. FIG. 9A is an explanatory diagram of parallel arrangement, and FIG. 9B is an explanatory diagram of shift arrangement.
Compared to the first embodiment of FIG. 3, the two heads of the second embodiment are each provided with a clear ink nozzle row that discharges ultraviolet curable clear ink instead of the white nozzle row.

The clear ink ejected by the clear ink nozzle array has a function as a fixing material for improving fixability and a function as a glossing material for improving glossiness.
When clear ink is used as a fixing material, a clear image is applied to a medium to form a transparent image on the medium, and then a color image is formed thereon. Thereby, the transparent image under the color image becomes a fixing layer, and the fixability of the color image to the medium is improved. In the following description, such printing is referred to as “printing with a fixing material”.
When clear ink is used as a glossy material, a color image is formed on a medium, and then a clear image is applied thereon to form a transparent image. Thereby, the transparent image on the color image becomes a coating layer, and the glossiness of the color image is improved. In the following description, such printing is referred to as “glossy printing”.

<Printing in parallel layout>
In the parallel arrangement, the print ranges of the two heads almost overlap. If you try to print a transparent image and a color image in such a state (printing with a fixing material or glossy printing), it takes a long time to print (because you cannot print a transparent image and a color image in the same pass). .
For this reason, when only a color image is printed, printing in a parallel arrangement is performed. The controller 10 arranges two heads in parallel when only a color image is printed using the color nozzle row group (when a transparent image is not formed). When printing is performed in a parallel arrangement, a color nozzle group is used for both of the two heads, and a clear ink nozzle row is not used.

  10A to 10D are explanatory diagrams of printing in a parallel arrangement in the second embodiment. Since the clear ink nozzle row is not used in the parallel arrangement, if attention is paid to the region of the nozzle row for ejecting ink and the pre-curing irradiation unit 61 for irradiating ultraviolet rays, the same printing as in FIGS. 4A to 4D of the first embodiment is performed. Is the action.

  Also in the second embodiment, when printing a color image in a parallel arrangement, two printing modes, a high resolution mode and a speed priority mode, can be executed.

<Printing with shift arrangement>
In the shift arrangement, the print ranges of the two heads are different. When a transparent image and a color image are overlaid and printed (printing with a fixing material or glossy printing), the printing range of the transparent image and the printing range of the color image cannot be overlapped in the same pass. Therefore, the controller 10 arranges the two heads in a shifted arrangement, forms a transparent image with one head, and forms a color image with the other head, so that the print range of each image does not overlap. . And the controller 10 prints so that the other image may be superimposed after temporarily curing one image.

-Printing with fixing material Printing with fixing material is printing in which a color image is formed on a transparent image after the transparent image is formed on a medium.
11A to 11B are explanatory diagrams of printing with a fixing material in a shift arrangement. Compared with FIGS. 7A to 7D of the first embodiment, instead of the white nozzle row ejecting white ink to form a background image, the clear ink nozzle row ejects clear ink to form a transparent image. Different.

Glossy printing Glossy printing is printing in which a color image is formed on a medium and then a transparent image is formed on the color image.
12A to 12B are explanatory diagrams of glossy printing in the shift arrangement. Compared with the above-described printing with a fixing material (FIGS. 11A to 11D), the head for forming a color image and the head for forming a transparent image are reversed. Compared with the back printing (FIGS. 8A to 8D) of the first embodiment described above, the clear ink nozzle row ejects clear ink instead of the white nozzle row ejecting white ink to form a background image. The difference is that a transparent image is formed. In addition, the back printing in the first embodiment is mainly for printing on a transparent medium, whereas the gloss printing in the second embodiment is not limited to printing on a transparent medium, for example, printing on plain paper or glossy paper. But it ’s okay.

=== Third Embodiment ===
13A and 13B are explanatory views of the lower surface of the carriage according to the third embodiment. FIG. 13A is an explanatory diagram of parallel arrangement, and FIG. 13B is an explanatory diagram of shift arrangement.
The first head 41A includes a color nozzle row group composed of four nozzle rows and a clear ink nozzle row. That is, the first head 41A of the third embodiment includes a clear ink nozzle row instead of the white nozzle row as compared to the first embodiment of FIG.
The second head 41B includes a color nozzle row group composed of four nozzle rows and a white nozzle row. In other words, unlike the first head 41A, the second head 41B includes a white nozzle row instead of a clear ink nozzle row.

  Thus, in the third embodiment, the first head 41A and the second head 41B are common in that they include a color nozzle row group. However, the third embodiment is different in that the first head 41A includes a clear ink nozzle array, whereas the second head 41B includes a white nozzle array.

<Printing in parallel layout>
In the parallel arrangement, the print ranges of the two heads almost overlap. If printing is performed with a transparent image or background image superimposed on a color image in such a state, printing takes time (because the transparent image and the color image cannot be printed in the same pass).
For this reason, when only a color image is printed, printing in a parallel arrangement is performed. The controller 10 arranges two heads in parallel when only a color image is printed using a group of color nozzle rows (when a transparent image or a background image is not formed). When printing is performed in a parallel arrangement, a color nozzle group is used for both of the two heads, and a clear ink nozzle row and a white nozzle row are not used.

  14A to 14D are explanatory diagrams of printing in the parallel arrangement in the third embodiment. Since the clear ink nozzle row and the white nozzle row are not used in the parallel arrangement, attention is paid to the nozzle row that ejects ink and the region of the pre-curing irradiation unit 61 that irradiates ultraviolet rays. This is the same printing operation as 4D.

  Also in the third embodiment, when printing a color image in a parallel arrangement, two printing modes, a high resolution mode and a speed priority mode, can be executed.

<Printing with shift arrangement>
In the shift arrangement, the print ranges of the two heads are different. When a transparent image or a background image is overlaid on a color image, the transparent image, the background image, and the color image cannot be overlapped in the same pass. Therefore, the controller 10 divides the print area by the two heads into three areas: an area for forming a background image, an area for forming a color image, and an area for forming a transparent image. I try not to. Since the width of the print area in the conveyance direction is expanded to 2 L by the shift arrangement, each area can be set wide even if the print area is divided into three areas.

・ Glossy surface printing (thick clear ink)
Here, printing in which clear ink is applied twice on an image printed by surface printing will be described. By applying the clear ink twice in layers (by thickly applying the clear ink), the surface is smoothed more uniformly and gloss is improved.
15A to 15G are explanatory diagrams of front-surface gloss printing (clear ink thick coating).

First, in pass 1, as shown in FIG. 15A, the controller 10 moves the carriage 31 in the moving direction to move the nozzles on the upstream side in the transport direction of the white nozzle row of the second head 41B (the upper half nozzle in FIG. 15A). ) Discharge white ink. As a result, a white background image having a width in the transport direction of L / 2 (0.5 inch) is formed on the medium.
In pass 1, the controller 10 irradiates ultraviolet light from the pre-curing irradiation unit 61 on the upstream side in the moving direction of the carriage 31 (left side in FIG. 15A). As a result, the white ink immediately after landing on the medium is irradiated with ultraviolet light, and the surface of the ink is cured (temporarily cured). Thereby, even if the color ink is ejected on the white ink, the bleeding between the white ink and the color ink can be suppressed. Since it is not necessary to irradiate the region where the background image is not formed with the ultraviolet light, the temporary curing irradiation unit 61 irradiates the ultraviolet light from the region where the position in the transport direction is the same as the nozzle that ejected the white ink. In addition, ultraviolet light is not irradiated from the region downstream in the transport direction (ultraviolet light is irradiated from the upper quarter region of the temporary curing irradiation unit 61 on the left side of FIG. 15A).

  Next, as illustrated in FIG. 15B, the controller 10 transports the medium in the transport direction. The carry amount at this time is L / 2 (0.5 inch). Accordingly, the area where the background image is formed in FIG. 15A is positioned in the color image print area in pass 2 (second pass), and the unprinted portion of the medium is supplied to the background image print area in pass 2 Is done.

  Then, as illustrated in FIG. 15C, the controller 10 causes the pass 2 to be performed. Also in pass 2, the controller 10 moves the carriage 31 in the movement direction, and discharges white ink from the nozzles on the upstream side in the transport direction of the white nozzle row of the second head 41B (the upper half nozzle in FIG. 15A). As a result, a white background image having a width in the transport direction of L / 2 (0.5 inch) is formed on the medium.

  In pass 2, as shown in FIG. 15C, the controller 10 moves the nozzles on the downstream side in the transport direction of the color nozzle row group (K, C, M, Y) of the second head 41B (the lower half in FIG. 15C). The color ink is discharged from the nozzle. As a result, a color image having a width of L / 2 (0.5 inch) in the transport direction is formed on the medium on the background image formed in pass 1 (front printing).

  Further, in pass 2, the controller 10 transmits ultraviolet light from a region upstream of the transport direction of the pre-curing irradiation unit 61 (upper half region in FIG. 15C) on the upstream side in the moving direction of the carriage 31 (right side in FIG. 15C). Is irradiated. In pass 2, the temporary curing irradiation unit 61 irradiates not only the background image formed by the white nozzle array of the second head 41B but also the color image formed by the color nozzle array group of the second head 41B. To do. In other words, the pre-curing irradiation unit 61 irradiates ultraviolet light from an area where the printing area of the second head 41B and the position in the transport direction are the same.

  After pass 2, as shown in FIG. 15D, the controller 10 transports the medium in the transport direction. The carry amount at this time is L / 2 (0.5 inch). Accordingly, the area where the color image is formed in FIG. 15C is located in the transparent image print area in pass 3, the area where the background image is formed is located in the color image print area in pass 3, and The unprinted portion is supplied to the background image print area in pass 3.

  Then, as illustrated in FIG. 15E, the controller 10 causes the pass 3 to be performed. Also in pass 3, the controller 10 moves the carriage 31 in the movement direction and discharges white ink from the nozzles on the upstream side in the transport direction of the white nozzle row of the second head 41 (the upper half nozzle in FIG. 15E). Color ink is ejected from the nozzles in the transport direction downstream of the color nozzle row group (K, C, M, Y) of the second head 41B (lower half nozzles in FIG. 15E).

  Further, in pass 3, as shown in FIG. 15E, the controller 10 ejects clear ink from the nozzles on the upstream side in the transport direction of the clear ink nozzle row of the first head 41A (the upper half nozzle in FIG. 15E). As a result, a transparent image is formed on the surface-printed image having a width in the transport direction of L / 2 (0.5 inch).

  Further, in the case of pass 3, the controller 10 has an area 3/4 upstream in the transport direction of the pre-curing irradiation unit 61 on the upstream side in the movement direction of the carriage 31 (left side in FIG. 15E) (on the upper 3/4 in FIG. 15E). Irradiate ultraviolet light from the region. In pass 3, the pre-curing irradiation unit 61 irradiates not only the background image and color image formed by the second head 41B but also the color image formed by the color nozzle array group of the first head 41A. . In other words, the pre-curing irradiation unit 61 irradiates the ultraviolet light from an area where the printing area of the two heads and the position in the transport direction are the same.

  After pass 3, as shown in FIG. 15F, the controller 10 transports the medium in the transport direction. The carry amount at this time is L / 2 (0.5 inch).

  Then, as illustrated in FIG. 15G, the controller 10 causes the pass 4 to be performed. Also in pass 4, the controller 10 moves the carriage 31 in the movement direction and discharges white ink from the nozzles on the upstream side in the transport direction of the white nozzle row of the second head 41 (the upper half nozzle in FIG. 15E). Color ink is ejected from the nozzles in the transport direction downstream of the color nozzle row group (K, C, M, Y) of the second head 41B (lower half nozzles in FIG. 15E).

  In pass 4, as shown in FIG. 15G, the controller 10 discharges clear ink from the clear ink nozzle row of the first head 41A. As a result, a transparent image having a width L (1 inch) in the conveyance direction is formed. However, in the lower half area of the transparent image formed at this time, the clear ink already formed in pass 3 is present. That is, the clear ink is applied twice in a region where the width in the transport direction is L / 2 (0.5 inch).

  Furthermore, in pass 4, the controller 10 irradiates ultraviolet light from the pre-curing irradiation unit 61 on the upstream side in the movement direction of the carriage 31 (right side in FIG. 15G). In pass 4, the pre-curing irradiation unit 61 irradiates not only the background image and color image formed by the second head 41B but also the transparent image formed by the clear ink nozzle array of the first head 41A. Therefore, ultraviolet light is irradiated from all regions. In other words, the pre-curing irradiation unit 61 irradiates the ultraviolet light from an area where the printing area of the two heads and the position in the transport direction are the same.

  Then, after FIG. 15G, the controller 10 alternately repeats the operation (pass) for moving the carriage 31 in the moving direction and the conveying operation. In each pass, the controller 10 discharges white ink from the nozzles on the upstream side in the transport direction of the white nozzle row of the second head 41 (the upper half nozzle in FIG. 15G), and at the same time, the color nozzle row of the second head 41B. Color ink is ejected from nozzles on the downstream side in the transport direction of the group (K, C, M, Y) (lower half nozzles in FIG. 15G). Also, clear ink is ejected from the clear ink nozzle row of the first head 41A. In other words, in each pass, the controller 10 forms a background image in the upstream L / 2 area of the printing area having a width in the conveyance direction of 2 L, and forms a color image in the adjacent L / 2 area. And a transparent image is formed in the downstream L region (double-width region). In each pass, the controller 10 irradiates ultraviolet light from the temporary curing irradiation unit 61 on the upstream side in the movement direction of the carriage 31 to temporarily cure the background image, the color image, and the transparent image. By repeating such a pass and the transport operation of the transport amount of L / 2, it is possible to perform gloss printing in which clear ink is applied twice on the surface printed image.

・ Glossy surface printing (uniform coating)
Here, a description will be given of printing in which clear ink is applied once on an image printed by surface printing. As shown in FIG. 15E, even if the pass for forming the background image, the color image, and the transparent image with the width of L / 2 and the transport operation of the transport amount of L / 2 are repeated, the top printed image is printed. Although printing with a clear ink applied once is possible, the printing speed is faster in the method described below.

  16A to 16E are explanatory views of front gloss printing (uniform coating). FIG. 16A is an explanatory diagram of path 1. FIG. 16B is an explanatory diagram of a transport operation performed after pass 1 (before pass 2). FIG. 16C is an explanatory diagram of path 2. FIG. 16D is an explanatory diagram of a transport operation performed after pass 2 (before pass 3). FIG. 16E is an explanatory diagram of path 3.

  The controller 10 alternately repeats the operation (pass) for moving the carriage 31 in the movement direction and the conveying operation. As shown in FIG. 16E, in each pass, the controller 10 ejects white ink from nozzles on the upstream side 2/3 of the white nozzle row of the second head 41 (upper 2/3 nozzles in FIG. 16E). At the same time, the color ink is ejected from the 1/3 nozzle (the lower 1/3 nozzle in FIG. 16E) on the downstream side in the transport direction of the color nozzle row group (K, C, M, Y) of the second head 41B. In addition, the color ink is ejected from the nozzle on the upstream side 1/3 of the color nozzle row group (K, C, M, Y) of the first head 41A (upper 1/3 nozzle in FIG. 16E), and the first Clear ink is ejected from 2/3 nozzles on the downstream side in the transport direction of the clear ink nozzle row of one head 41A (lower 2/3 nozzles in FIG. 16E). In other words, in each pass, the controller 10 forms a background image in the upstream 2L / 3 region of the printing region having a width of 2L, and forms a color image in the central 2L / 3 region. Then, a transparent image is formed in the area on the downstream side 2L / 3. In each pass, the controller 10 irradiates ultraviolet light from the temporary curing irradiation unit 61 on the upstream side in the movement direction of the carriage 31 to temporarily cure the background image, the color image, and the transparent image. By repeating such a pass and a transport operation of a transport amount of 2L / 3, it is possible to perform gloss printing in which clear ink is applied once on the surface printed image.

  According to the printing method of FIG. 16A to FIG. 16E, the printing speed is faster than the printing method of FIG. 15A to FIG.

・ Glossy surface printing (white ink thick coating)
Here, a description will be given of printing in which a color image and a transparent image are formed after a background image is printed twice. Note that by applying the white ink twice in layers (by thickly applying the white ink), the background image can be printed darkly, and the visibility of the color image formed on the background image is improved. .

  FIGS. 17A to 17G are explanatory diagrams of front-surface gloss printing (white ink thick coating). FIG. 17A is an explanatory diagram of path 1. FIG. 17B is an explanatory diagram of a transport operation performed after pass 1 (before pass 2). FIG. 17C is an explanatory diagram of path 2. FIG. 17D is an explanatory diagram of a transport operation performed after pass 2 (before pass 3). FIG. 17E is an explanatory diagram of pass 3. FIG. 17F is an explanatory diagram of a transport operation performed after pass 3 (before pass 4). FIG. 17G is an explanatory diagram of path 4.

  The controller 10 alternately repeats the operation (pass) for moving the carriage 31 in the movement direction and the conveying operation. In each pass, the controller 10 ejects white ink from the white nozzle row of the second head 41B. Also, color ink is ejected from the nozzles (upper half nozzles in FIG. 17G) on the upstream side in the transport direction of the color nozzle row group (K, C, M, Y) of the first head 41A, and the first head 41A is cleared. Clear ink is ejected from the nozzles on the downstream side in the transport direction of the ink nozzle row (the lower half nozzle in FIG. 17G). In other words, in each pass, the controller 10 forms a background image in the upstream L area of the printing area having a width in the transport direction of 2L, and forms a color image in the adjacent L / 2 area. A transparent image is formed in the downstream L / 2 region. In each pass, the controller 10 irradiates ultraviolet light from the temporary curing irradiation unit 61 on the upstream side in the movement direction of the carriage 31 to temporarily cure the background image, the color image, and the transparent image. A color image and a transparent image can be formed on the background image printed twice by repeating such a pass and the transport operation of the transport amount of L / 2.

=== Summary ===
FIG. 18 is an explanatory diagram of the relationship between the arrangement of the first embodiment to the third embodiment and the type of ink to be ejected.
In any of the embodiments, the first head also includes the second head so that both the printing in which the first head ejects the color ink and the second head ejects the color ink in the shift arrangement are possible. A color nozzle array group is also provided on the head. In any of the embodiments, not only different types of ink are ejected in the shift arrangement, but also the same type of ink (color ink) from the first head 41A and the second head 41B in the parallel arrangement. ) Is discharged. As described above, not only printing by the shift arrangement but also two heads can eject the same ink in the case of the parallel arrangement, thereby enabling various printing.

=== Others ===
The above embodiment is mainly described for a printer, but it goes without saying that the disclosure includes a printing apparatus, a printing method, a program, a storage medium storing the program, and the like.

  The above-described embodiments are for facilitating understanding of the present invention, and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the present invention.

<About nozzle>
In the above-described embodiment, ink is ejected using a piezoelectric element. However, the method for discharging the liquid is not limited to this. For example, other methods such as a method of generating bubbles in the nozzle by heat may be used.

<About ink>
In the above-described embodiment, a UV ink having a property of being cured when irradiated with ultraviolet rays has been used. However, UV ink is not necessarily used. Even if UV ink is not ejected from the head, not only printing by shift arrangement but also two heads can eject the same ink in the case of parallel arrangement, thereby enabling various printing. If the ink is not UV ink, the printer 1 may not include the irradiation unit 60.

1 printer, 10 controller,
11 Interface unit, 12 CPU,
13 memory, 14 unit control circuit,
20 transport units, 21 transport rollers,
30 Carriage unit, 31 Carriage,
40 head units, 41 heads, 41A first head, 41B second head,
50 detector groups, 60 irradiation units, 61 temporary curing irradiation unit, 62 main curing irradiation unit

Claims (7)

A transport mechanism for transporting the medium in the first direction;
A first head that includes a plurality of nozzle rows composed of a plurality of nozzles arranged in the first direction, and that can eject a plurality of types of ink;
A second head comprising a plurality of nozzle rows composed of a plurality of nozzles arranged in the first direction and capable of discharging a plurality of types of ink;
A carriage for moving the first head and the second head along a second direction intersecting the first direction;
The first head and the second head are arranged in parallel in the second direction, and the first head and the second head are shifted and arranged at different positions in the first direction. A head moving mechanism for changing the positional relationship of the second head in the first direction;
A printing apparatus comprising: a controller for controlling ejection of the ink from the first head and the second head;
The controller is
In the case of the parallel arrangement, the same type of ink is ejected from the first head and the second head, respectively.
In the case of the shift arrangement, different types of ink are ejected from the first head and the second head, respectively. The printing apparatus according to claim 1,
In the case of the parallel arrangement, the controller includes the nozzle of the second head between a dot row composed of a plurality of dots arranged in the two directions formed by the nozzle of the first head. To form a dot row composed of a plurality of dots arranged in the two directions . The printing apparatus according to claim 1,
In the case of the parallel arrangement, the controller forms dots by the nozzles of the second head between dots arranged in the second direction formed by the nozzles of the first head. Printing device to do. The printing apparatus according to claim 2 or 3,
The ink ejected from the first head and the second head is ink that hardens when irradiated with light,
The carriage is provided with an irradiation unit for irradiating the light,
The irradiation unit irradiates the light from an area where the position in the first direction is the same as the print area in the parallel arrangement, and also irradiates the light from an area where the position in the first direction is different from the print area. The printing apparatus characterized by performing. The printing apparatus according to claim 4,
The irradiation unit is provided so as to sandwich the first head and the second head from the second direction,
In the case of the parallel arrangement, the irradiating unit is arranged on the upstream side in the direction in which the carriage moves with respect to the print area when irradiating the light from an area whose position in the first direction is different from that of the print area. A printing apparatus that emits light. The printing apparatus according to any one of claims 1 to 5,
In the shift arrangement, the controller forms an image with the first head on an image formed with the second head. A transport mechanism for transporting the medium in the first direction;
A first head that includes a plurality of nozzle rows composed of a plurality of nozzles arranged in the first direction, and that can eject a plurality of types of ink;
A second head comprising a plurality of nozzle rows composed of a plurality of nozzles arranged in the first direction and capable of discharging a plurality of types of ink;
A carriage for moving the first head and the second head along a second direction intersecting the first direction;
The first head and the second head are arranged in parallel in the second direction, and the first head and the second head are shifted and arranged at different positions in the first direction. A head moving mechanism for changing the positional relationship of the second head in the first direction;
A printing method for a printing apparatus comprising:
In the case of the parallel arrangement, the same type of ink is ejected from the first head and the second head, respectively.
In the case of the shift arrangement, a different type of ink is ejected from the first head and the second head, respectively.

Images