Printing apparatus

Abstract

To adjust a drying period to an appropriate length while suppressing change in an image quality.SOLUTION: A printer according to the present disclosure includes a first head having a first nozzle array where a plurality of first nozzles capable of discharging a first liquid are aligned in a first direction, a second head having a second nozzle array where a plurality of second nozzles capable of discharging a second liquid discharged onto the first liquid are aligned in the first direction, a first moving unit for relatively moving the first head, the second head, and a medium in the first direction, and a second moving unit of moving the first head and the second head in a second direction crossing the first direction, and changes an interval in the first direction between the use range of the first nozzle array and the use range of the second nozzle array while maintaining the length in the first direction of each of the use range of the first nozzle array and the use range of the second nozzle array.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a printing apparatus.

Background Art

[0002] Patent Document 1 describes an apparatus that forms a second image by discharging a second liquid onto a first image formed on a recording medium by discharging a first liquid. Further, in Patent Document 1, based on the amount of the second liquid to be adhered to the recording medium, at least one of the number of nozzles for discharging the first liquid or the number of nozzles for discharging the second liquid is changed, thereby changing the time interval (drying time) from the formation of the first image to the formation of the second image.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the number of nozzles for discharging liquid is changed as described in Patent Document 1, there is a risk that the image quality may change.

[0005] An object of the present invention is to adjust the drying period to an appropriate length while suppressing a change in image quality.

Means for Solving the Problems

[0006] The first main invention for achieving the above objective is a printing apparatus comprising: a first head having a first nozzle row in which a plurality of first nozzles capable of discharging a first liquid are arranged in a first direction; a second head having a second nozzle row in which a plurality of second nozzles capable of discharging a second liquid to be discharged onto the first liquid are arranged in the first direction; a first moving unit for moving the first head and the second head and the medium relative to each other in the first direction; and a second moving unit for moving the first head and the second head in a second direction intersecting the first direction, wherein the spacing between the operating ranges of the first nozzle row and the operating ranges of the second nozzle row in the first direction is changed while maintaining the respective lengths of the operating ranges of the first nozzle row and the operating ranges of the second nozzle row in the first direction. Furthermore, the main second invention for achieving the above objective is a printing apparatus comprising: a first head having a first nozzle row in which a plurality of first nozzles capable of discharging a first liquid are arranged in a first direction; a second head having a second nozzle row in which a plurality of second nozzles capable of discharging a second liquid to be discharged onto the first liquid are arranged in the first direction; a first moving unit for moving the first head and the second head and the medium relative to each other in the first direction; and a second moving unit for moving the first head and the second head in a second direction intersecting the first direction, wherein the distance in the first direction between the usable range of the first nozzle row and the usable range of the second nozzle row is changed while maintaining the amount of movement when the first moving unit moves the first head and the second head and the medium relative to each other in the first direction.

[0007] Other features of the present invention will be revealed by the description herein. [Effects of the Invention]

[0008] According to the present invention, it is possible to adjust the drying period to an appropriate length while suppressing changes in image quality. [Brief explanation of the drawing]

[0009] [Figure 1] Figures 1A and 1B are explanatory diagrams illustrating the basic configuration of the printing device 1. [Figure 2]Figure 2 is an explanatory diagram of the configuration of the head unit 40. [Figure 3] Figures 3A to 3F are explanatory diagrams illustrating the dot formation process by the nozzle row 44. [Figure 4] Figure 4A is an explanatory diagram showing the dot formation process in Figures 3A to 3F using a different notation. Figure 4B is an explanatory diagram of multipass printing. [Figure 5] Figure 5 is an explanatory diagram showing the case where the usable range of nozzle row 44 is narrowed and 4-pass printing is performed. [Figure 6] Figure 6 is an explanatory diagram of image layers. [Figure 7] Figure 7 is an explanatory diagram of a printing method (dot formation method) using a processing liquid nozzle row 44A and an ink nozzle row 44B. [Figure 8] Figure 8 is an explanatory diagram of a dot formation method that includes a drying period. [Figure 9] Figure 9 is an explanatory diagram for adjusting the spacing between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B. [Figure 10] Figure 10 is an explanatory diagram of the dot formation method when the temperature is high or the humidity is low. [Figure 11] Figure 11 is an explanatory diagram of the dot formation method when the temperature is low or the humidity is high. [Figure 12] Figure 12 is an explanatory diagram of the dot formation method when the temperature becomes high or the humidity becomes low during printing. [Figure 13] Figure 13 is an explanatory diagram of the dot formation method when the temperature becomes low or the humidity becomes high during printing. [Figure 14] Figures 14A and 14B are explanatory diagrams of the first modified example. [Figure 15] Figures 15A and 15B are explanatory diagrams of a second modified example. [Figure 16] Figures 16A and 16B are explanatory diagrams of the third modified example. [Modes for carrying out the invention]

[0010] ===First Embodiment=== <Configuration> FIG. 1A and FIG. 1B are explanatory diagrams of an example of the configuration of the printing apparatus 1. FIG. 1A is a schematic explanatory diagram of the appearance of the printing apparatus 1. FIG. 1B is a block diagram of the printing apparatus 1. FIG. 2 is an explanatory diagram of the configuration of the head unit 40.

[0011] In the following description, the direction in which a plurality of nozzles 45 constituting the nozzle row 44 are arranged may be referred to as the "first direction". In the case of the printing apparatus 1 shown in FIG. 1A, since the first direction corresponds to the moving direction of the medium M, it may be referred to as the "transport direction". The side of the unused area of the medium M as viewed from the nozzle row may be referred to as "upstream (upstream side)", and the opposite side may be referred to as "downstream (downstream side)". In the case of the printing apparatus 1 shown in FIG. 1A, the supply side of the medium M is referred to as "upstream (upstream side)", and the discharge side of the medium M is referred to as "downstream (downstream side)". Note that the first direction may also be referred to as the "sub-scanning direction". Also, the direction in which the carriage 31 (or the head 41) moves may be referred to as the "second direction". The second direction is a direction that intersects the first direction. The second direction may be referred to as the "scanning direction" or the "main scanning direction".

[0012] The printing apparatus 1 is an apparatus that prints an image on a medium M (printing paper, printing film, etc.). Specifically, the printing apparatus 1 is an inkjet printer. The printing apparatus 1 includes a first moving unit 20, a second moving unit 30, a head unit 40, a heating device 50, an acquisition unit 60, and a controller 70.

[0013] The first moving unit 20 is a unit that relatively moves the head 41 (41A, 41B) and the medium M in the first direction. Here, the first moving unit 20 is a conveying unit that moves the medium M in the first direction (conveying direction). Here, the first moving unit 20 (conveying unit) has, for example, a conveying roller 21 and a conveying motor 22. The conveying roller 21 is a member that conveys the medium M in the conveying direction by rotating. The conveying motor 22 is a motor (driving unit) for rotating the conveying roller 21. Note that the first moving unit 20 is not limited to the configuration using the conveying roller 21. For example, the first moving unit 20 may have a conveying table (flat bed) and be configured to convey the medium M in the conveying direction by moving this conveying table. Also, the first moving unit 20 is not limited to moving the medium M in the first direction (conveying direction). For example, the first moving unit 20 may relatively move the head 41 (41A, 41B) and the medium M in the first direction by moving the second moving unit 30 (carriage unit) in the first direction. In the following description, the first moving unit 20 relatively moving the head 41 (41A, 41B) and the medium M in the first direction may be referred to as the "first moving operation". The medium M may be a long printing medium such as a roll paper or a single sheet of paper. Also, the medium M is not limited to paper and may be a film, cloth, or the like.

[0014] The second moving unit 30 is a unit that moves the heads 41 (41A, 41B) in a second direction. The second moving unit 30 moves the heads 41 mounted on the carriage 31 in a second direction by moving the carriage 31 in a second direction. In other words, the second moving unit 30 is a carriage unit that moves the carriage 31. The second moving unit 30 has a carriage 31 and a carriage motor 32. The carriage 31 is a member that moves back and forth in a second direction (scanning direction) and mounts the heads 41 (first head 41A and second head 41B; described later). The carriage motor 32 is a motor (drive unit) for moving the carriage 31 in the scanning direction. In the following description, the movement of the heads 41 (41A, 41B) by the second moving unit 30 in a second direction may be referred to as the "second moving operation".

[0015] The head unit 40 is a unit for ejecting liquid (ink or processing liquid) onto the medium M. The head unit 40 has a first head 41A and a second head 41B.

[0016] The first head 41A is a head that discharges the first liquid. The first head 41A has a first nozzle row 44A in which a plurality of first nozzles 45A capable of discharging the first liquid are arranged in a first direction (conveying direction). The second head 41B is a head that discharges the second liquid. The second liquid is a different liquid from the first liquid and is discharged on top of the first liquid. The second head 41B has a second nozzle row 45B in which a plurality of second nozzles 45B capable of discharging the second liquid are arranged in a first direction (conveying direction). In the first embodiment, the first head 41A is a processing liquid head that discharges processing liquid (corresponding to the first liquid), and the second head 41B is an ink head that discharges ink (corresponding to the second liquid). However, as will be described later, the first head 41A does not have to be a processing liquid head, and the second head 41B does not have to be an ink head. In the following explanation, the processing liquid head (corresponding to the first head) will be denoted by the code 41A, and the ink head (corresponding to the second head) will be denoted by the code 41B.

[0017] The processing liquid head 41A is a head having multiple nozzles (processing liquid nozzles 45A; corresponding to the first nozzles) for discharging the processing liquid. The processing liquid is a liquid that may also be called a primer, optimizer, pretreatment agent, adjusting agent, clear ink, special ink, or primer ink. The processing liquid may also be a liquid that thickens the ink or agglomerates and insolubilizes the colorant to fix the ink to the medium M. Here, the processing liquid is a transparent liquid. However, the processing liquid does not have to be transparent. The processing liquid head 41A has multiple nozzle rows (processing liquid nozzle rows 44A; corresponding to the first nozzle rows) (here, the processing liquid head 41A has four processing liquid nozzle rows 44A). The multiple processing liquid nozzle rows 44A are arranged in a second direction (scanning direction). Each processing liquid nozzle row 44A consists of multiple nozzles (processing liquid nozzles 45A) arranged in a first direction (conveying direction). Here, each processing liquid nozzle row 44A is composed of multiple nozzles (processing liquid nozzles 45A) arranged in a staggered pattern. In other words, each processing liquid nozzle row 44A is composed of two nozzle groups, and each of the two nozzle groups has multiple nozzles (processing liquid nozzles 45A) arranged at a predetermined pitch in the first direction (conveying direction), and one nozzle group has multiple nozzles (processing liquid nozzles 45A) arranged in the conveying direction, offset by half a pitch in the conveying direction from the nozzles (processing liquid nozzles 45A) of the other nozzle group. However, each processing liquid nozzle row 44A may be composed of multiple processing liquid nozzles 45A arranged in a single row in the conveying direction. Also, the processing liquid head 41A does not have to have multiple processing liquid nozzle rows 44A, and the processing liquid head 41A may have only one processing liquid nozzle row 44A. In the following description, even if a nozzle row 44(44A) is composed of multiple nozzles 45(45A) arranged in a staggered pattern, it may be described as a nozzle row in which multiple nozzles are arranged in a single row in the conveying direction. In the following explanation, the length of the processing liquid nozzle row 44A in the first direction (conveying direction) will be denoted as L1.

[0018] The ink head 41B is a head having multiple nozzles (ink nozzles 45B; corresponding to the second nozzle) that eject ink. Ink is a liquid used to form dots (ink dots) that make up an image (ink image; color image) on the medium M. Ink is a liquid sometimes called color ink or process ink. The ink head 41B has multiple nozzle rows (ink nozzle rows 44B; corresponding to the second nozzle rows). The multiple ink nozzle rows 44B are arranged in a line in the scanning direction. For example, the ink head 41B has a black ink nozzle row (Bk) that ejects black ink, a cyan ink nozzle row (C) that ejects cyan ink, a magenta ink nozzle row (M) that ejects magenta ink, and a yellow ink nozzle row (Y) that ejects yellow ink, and the four color ink nozzle rows 44B (black nozzle row, cyan nozzle row, magenta nozzle row, and yellow nozzle row) are arranged in a line in the scanning direction. Note that the ink colors are not limited to black, cyan, magenta, and yellow.

[0019] Each ink nozzle row 44B, like the processing liquid nozzle row 44A, has multiple nozzles (ink nozzles 45B) arranged in the first direction (conveying direction). Here, each ink nozzle row 44B, like the processing liquid head 41A, is composed of multiple nozzles (ink nozzles 45B) arranged in a staggered pattern. However, each ink nozzle row 44B may also be composed of multiple ink nozzles 45B arranged in a single row in the conveying direction. Also, the ink head 41B does not need to have multiple ink nozzle rows 44B. In the following description, the length of the ink nozzle row 44B in the first direction (conveying direction) is denoted as L1. However, the length of the ink nozzle row 44B in the conveying direction may differ from the length of the processing liquid nozzle row 44A.

[0020] As shown in Figure 2, the processing liquid head 41A (corresponding to the first head) is positioned upstream in the first direction (upstream in the transport direction) of the ink head 41B (corresponding to the second head), and the processing liquid nozzle row 44A is positioned upstream in the transport direction of the ink nozzle row 44B. This ensures that ink (corresponding to the second liquid) is discharged onto the processing liquid (corresponding to the first liquid). Furthermore, as will be described later, this reduces the number of unused nozzles 45 (45A, 45B). However, the processing liquid head 41A and the ink head 41B may be arranged side by side in the second direction (scanning direction), and the processing liquid nozzle row 44A and the ink nozzle row 44B may be positioned at the same location in the first direction (transport direction). Alternatively, a portion of the processing liquid nozzle row 44A and the ink nozzle row 44B may be positioned in an overlapping location in the first direction (transport direction).

[0021] As shown in Figure 1B, the head unit 40 has a head drive unit 42. The head drive unit 42 is a drive unit that causes liquid (ink, processing liquid) to be ejected / not ejected from each nozzle of the processing liquid head 41A and the ink head 41B. The head drive unit 42 is, for example, a piezoelectric element if the head is piezoelectric. The controller 70 controls the ejection / non-ejection of liquid from each nozzle by controlling the head drive unit 42. The controller 70 controls the operating range 46 (described later) of the nozzle row 44 by controlling the head drive unit 42.

[0022] The heating device 50 is a device for heating the medium M (or liquid). The heating device 50 includes, for example, a heater 51 and a blower 52. The heater 51 is located below a support member (platen; not shown) that supports the medium M, and is a device for heating the medium M supported by the support member. The blower 52 is a device for blowing warm air onto the medium M. The heating device 50 may also include devices other than the heater 51 and blower 52. Furthermore, the printing apparatus 1 does not necessarily have to be equipped with a heating device 50.

[0023] The acquisition unit 60 acquires information on at least one of temperature and humidity. Here, the acquisition unit 60 is a sensor 61 that measures at least one of temperature and humidity. Here, the sensor 61 is an environmental sensor that measures both temperature and humidity. However, the sensor 61 may be configured to measure only one of temperature or humidity. The sensor 61 measures the environment (at least one of temperature and humidity) near the medium M from which the head ejects liquid. For example, the sensor 61 may be mounted on the carriage 31 or provided on a support member (platen) that supports the medium M. The sensor 61 outputs the measurement results (temperature data and humidity data) to the controller 70. In the following description, the case where the acquisition unit 60 is a sensor 61 is described, but the acquisition unit 60 may also be an input unit (e.g., an input screen or input button) into which information on at least one of temperature and humidity is input by the user. If the acquisition unit 60 is configured with an input unit instead of a sensor 61, it becomes unnecessary to provide a sensor 61, and the configuration of the printing apparatus 1 can be simplified. Furthermore, the acquisition unit 60 may acquire information on the temperature of the heating device 50 (the temperature of the heater 51 and the temperature of the hot air blown from the blower 52) by acquiring control signals that control the heating device 50. In other words, the acquisition unit 60 may be composed of a signal acquisition unit that acquires signals output from the controller 70 to the heating device 50. Note that the acquisition unit 60 is not limited to the sensor 61, input unit and signal acquisition unit, and is sufficient if it can acquire information on at least one of temperature and humidity.

[0024] The controller 70 is a control unit that is responsible for controlling the printing device 1. Based on print commands from an external computer, the controller 70 controls the drive units of the printing device 1 (transport motor 22, carriage motor 32, head drive unit 42, heating device 50, etc.). As will be described later, the controller 70 controls the range in which the processing liquid is discharged from the processing liquid nozzle row 44A (operating range 46A; corresponding to the first operating range) and the range in which ink is discharged from the ink nozzle row 44B (operating range 46B; corresponding to the second operating range) based on the measurement results of the sensor 61.

[0025] <Reference Explanation 1> Figures 3A to 3F are explanatory diagrams illustrating the dot formation process by the nozzle row 44. For the sake of simplicity, the dot formation process of one nozzle row 44 will be described here.

[0026] As shown in Figures 3A and 3B, the controller 70 moves the carriage 31 in the scanning direction (corresponding to the second direction), thereby moving the head 41 (nozzle row 44) in the scanning direction and ejecting liquid (ink or processing liquid) from the nozzles to form dots on the medium M. In the following description, the operation of moving the head 41 (nozzle row 44) in the scanning direction may be referred to as a "pass" (or "second movement operation" or "main scan"). The nth pass will be referred to as "pass n" and may be denoted as "Pn" in the figures. In Figure 3B, the area where dots can be formed in one pass (dot formation area) is hatched.

[0027] After moving the carriage 31 in the scanning direction (after forming dots on the medium M), the controller 70 transports the medium M in the transport direction, as shown in Figures 3C and 3D. In the following description, this operation may be referred to as the "transport operation" (or "first movement operation" or "sub-scanning"). The transport operation causes the downstream end of the dot formation area of ​​the previous pass to move outside the dot formation area of ​​the next pass (see Figures 3E and 3F), and the unused area of ​​the medium M is supplied to the upstream end of the dot formation area of ​​the next pass.

[0028] After the transport operation, the controller 70 causes the next pass to be performed, as shown in Figures 3E and 3F. In this way, the controller 70 alternately repeats the pass and transport operation to form dots on the medium M. If the amount of transport in one transport operation (corresponding to the amount of movement in the first movement operation) is shorter than the length of the dot formation area in the transport direction, the dot formation area will overlap with a part of the dot formation area of ​​the previous pass, as shown in Figure 3F. In Figure 3F, the overlapping dot formation areas of the two passes are shown with dark hatching.

[0029] Figure 4A is an explanatory diagram showing the dot formation process in Figures 3A to 3F using a different notation. Figure 4A shows the relative positional relationship of the nozzle row 44 in each pass with respect to the medium M. In the following explanation, the dot formation process in each pass may be shown by changing the position of the nozzle row 44 with respect to the medium M (in other words, by changing the relative position between the nozzle row 44 and the medium M), as shown in Figure 4A. The amount of positional change L3 of the nozzle row 44 in the first direction (conveying direction) in each pass in the figure indicates the amount of movement of the first movement operation performed between each pass, and here it indicates the amount of transport during the transport operation.

[0030] Figure 4B is an explanatory diagram of multi-pass printing. Multi-pass printing is a printing method in which dots to be formed in a predetermined area on the medium M (an area with a width corresponding to the amount transported in a single transport operation) are completed in multiple passes. Figure 4B shows the process of 4-pass printing, in which four passes are made for each area of ​​the medium M. "Pn" in the figure indicates the position of the nozzle row 44 in the nth pass (pass n).

[0031] In Figure 4B, area A1 is the area where dots were formed in four passes (passes 1-4). Area A2 is the area where dots were formed in three passes (passes 2-4). Area A3 is the area where dots were formed in two passes (passes 3 and 4). Area A4 is the area where dots were formed in one pass (pass 4). In the case of four-pass printing, all the dots to be formed are formed in area A1. Approximately 3 / 4 of the dots to be formed are formed in area A2. Approximately 1 / 2 of the dots to be formed are formed in area A3. Approximately 1 / 4 of the dots to be formed are formed in area A4. In area A4, the dots formed in each pass (passes 1-4) are distributed. In this way, with multi-pass printing, the dots formed in each pass are distributed, so the image quality can be improved compared to a printing method that completes the formation of all the dots in one pass (one-pass printing).

[0032] In the case of 4-pass printing, the transport volume L3 during transport operation is approximately 1 / 4 of the range of the nozzles that eject the liquid (ink or processing liquid) (the usable range of the nozzle row 44). In the case of 4-pass printing with ink ejected from all nozzles of the nozzle row 44, the transport volume L3 during transport operation is approximately 1 / 4 of the length L1 of the nozzle row.

[0033] Figure 5 is an explanatory diagram showing the case where the usable range of nozzle row 44 is narrowed and 4-pass printing is performed.

[0034] In the diagram, the area within the rectangular nozzle row 44 to which the nozzles that discharge liquid (ink or processing liquid) belong is hatched. Nozzles in the area without hatching are unused and do not discharge liquid. In the following explanation, the area within the rectangular nozzle row 44 to which the nozzles that discharge liquid (ink or processing liquid) belong (the hatched area in the diagram) may be referred to as the "used area," and the area to which the unused nozzles that do not discharge liquid belong (the area without hatching in the diagram) may be referred to as the "unused area." Here, the upstream half of the nozzle row 44 in the transport direction is the used area 46, and the downstream half in the transport direction is the unused area. Here, the length L2 of the used area 46 in the transport direction is half the length L1 of the nozzle row in the transport direction.

[0035] Even when performing 4-pass printing using half of the nozzle row 44, the transport volume L3 during transport operation is approximately 1 / 4 of the transport direction length L2 of the nozzle usage range 46. Note that the transport volume L3 during transport operation shown in Figure 5 is half the transport volume L3 during transport operation shown in Figure 4B. Thus, even when performing multi-pass printing with the same number of passes (e.g., 4-pass printing), if the transport direction length of the nozzle usage range differs, the transport volume during transport operation will differ. Since a difference in the transport volume during transport operation results in different transport direction lengths for each region A1 to A4 (see Figures 4B and 5), there is a risk of different image quality even when performing multi-pass printing with the same number of passes (e.g., 4-pass printing).

[0036] <Reference Explanation 2> Figure 6 is an explanatory diagram of the image layers. In the figure, the layer showing the processing solution image 91A (corresponding to the first image), the layer showing the ink image 91B (corresponding to the second image), and the layer showing the medium M are separated vertically. However, in reality, the processing solution image 91A and the ink image 91B are superimposed on the medium M.

[0037] The processed liquid image 91A is an image composed of dots formed by the processed liquid (processed liquid dots; first dots). The ink image 91B is an image (color image) composed of dots formed by ink (ink dots; second dots). The ink image 91B is an image formed on top of the processed liquid image 91A. As shown in the figure, the printing apparatus 1 forms the processed liquid image 91A, composed of processed liquid dots, on the medium M, and also forms the ink image 91B, composed of ink dots, on the medium M on which the processed liquid image 91A is formed. By forming ink dots on the medium M coated with the processed liquid, the ink dots can be suitably fixed to the medium M, and the image quality of the printed image can be improved.

[0038] Figure 7 is an explanatory diagram of a printing method (dot formation method) using a processing liquid nozzle row 44A and an ink nozzle row 44B. The figure shows the positional relationship between the ink nozzle row 44B and the processing liquid nozzle row 44A for passes 1 to 11 with respect to the medium M. As already explained, the processing liquid nozzle row 44A is located upstream of the ink nozzle row 44B in the transport direction. Here, the positions of the processing liquid nozzle row 44A and the ink nozzle row 44B in the scanning direction are shown together.

[0039] In region A1, all the processing liquid dots are formed by four passes (passes 1-4), and all the ink dots are formed by four passes (passes 5-8). Similarly, in regions A2-A4, all the processing liquid dots are formed by four passes, and all the ink dots are formed by four passes. In region A5, all the processing liquid dots are formed by four passes (passes 5-8), and approximately 3 / 4 of the ink dots are formed by three passes (passes 9-11). In pass 12 (not shown), processing liquid nozzle row 44A forms processing liquid dots in regions A9-A12 (A12 is not shown), and ink nozzle row 44B forms ink dots in regions A5-A8, thereby forming all the ink dots that should be formed in region A5.

[0040] In the dot formation method shown in Figure 7, processing liquid dots are formed in one pass, and then ink dots are formed in the immediately following pass. For example, focusing on region A1 in Figure 7, processing liquid dots are formed in region A1 by pass 4, and then ink dots are formed in region A1 by the immediately following pass 5. However, in this printing method, since the ink (second liquid) is applied on top of the processing liquid (first liquid) that has just been applied to the medium M, there is a risk that the ink dots may bleed, which may degrade the image quality of the printed image.

[0041] <Regarding the drying period> Figure 8 is an explanatory diagram of a dot formation method with a drying period. The figure shows the positional relationship between the processing liquid nozzle rows 44A and the ink nozzle rows 44B of passes 1 to 15 with respect to the medium M.

[0042] In the diagram, the hatched area of ​​the rectangular nozzle row indicates the usable area 46 (46A, 46B), while the unhatched area indicates the unused area. Here, the usable area 46 (46A, 46B) is located in the center of the nozzle row in the conveying direction, and the unused area is located at both ends of the nozzle row in the conveying direction (upstream and downstream ends). As will be described later, in order to adjust the width of the gap between the usable area 46A and the usable area 46B, it is desirable to place the usable area 46 (46A, 46B) in the center of the conveying direction and the unused area of ​​the nozzle row at both ends of the nozzle row in the conveying direction (upstream and downstream ends). However, the usable area 46 (46A, 46B) does not have to be in the center of the conveying direction; it can also be at the ends (upstream or downstream ends) in the conveying direction. Here, the length of the processing liquid nozzle row 44A is L1, and the length L2 in the transport direction of the usable range 46A of the processing liquid nozzle row 44A is half the length L1 in the transport direction of the processing liquid nozzle row 44A. Similarly, the length of the ink nozzle row 44B is L1, and the length L2 in the transport direction of the usable range 46B of the ink nozzle row 44B is half the length L1 in the transport direction of the ink nozzle row 44B. Furthermore, the transport volume L3 during transport operation is approximately 1 / 4 of the length L2 (the length in the transport direction of the usable range of the nozzle row 44). Note that the width in the transport direction of each region (A1 to A15) in the figure corresponds to the length L3.

[0043] The controller 70 places unused nozzles between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B, thereby creating a gap between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B. By leaving the nozzles at the downstream end of the processing liquid nozzle row 44A in the transport direction unused, and leaving the nozzles at the upstream end of the ink nozzle row 44B in the transport direction unused, a gap is created between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B. Here, the transport direction length L10 between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B corresponds to the transport volume of four transport operations.

[0044] The controller 70 alternately repeats a pass and transport operation with a gap between the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B. This allows ink dots to be formed after a drying period has passed following the formation of processing liquid dots in a certain pass. For example, focusing on region A1 in Figure 8, after processing liquid dots are formed in region A1 by pass 4, ink dots are formed in region A1 by pass 9 after a drying period equivalent to four passes (passes 5 to 8). In this way, by creating a gap between the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B, a drying period can be provided for the processing liquid applied to the medium M, thereby suppressing ink dot bleeding.

[0045] <Regarding adjustments to the drying period> Incidentally, if the drying period of the processing solution is too short, the ink dots may bleed, potentially degrading the quality of the printed image. On the other hand, if the drying period of the processing solution is too long, the processing solution applied to the medium M may aggregate and become uneven, potentially degrading the quality of the printed image formed on it. Therefore, the drying period of the processing solution must be set to an appropriate length. On the other hand, the appropriate drying period for the treatment solution varies depending on the environment. For example, when the temperature is high or the humidity is low, the treatment solution dries easily, so a shorter drying period is desirable. Conversely, when the temperature is low or the humidity is high, a longer drying period is desirable. Therefore, the controller 70 adjusts the drying period of the processing liquid by adjusting the distance between the working range 46A of the processing liquid nozzle row 44A and the working range 46B of the ink nozzle row 44B, as will be explained below. Furthermore, when the controller 70 adjusts the distance between the working range 46A of the processing liquid nozzle row 44A and the working range 46B of the ink nozzle row 44B, it maintains the length in the transport direction of each of the working ranges 46A of the processing liquid nozzle row 44A and the working range 46B of the ink nozzle row 44B, in other words, it maintains the transport amount during transport operation, thereby making the length in the transport direction of each region (each region A1 to A15 in Figure 8) the same before and after the change in the drying period, and suppressing differences in image quality.

[0046] Figure 9 is an explanatory diagram for adjusting the spacing between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B.

[0047] As already explained, the length in the transport direction of the processing liquid nozzle row 44A and the ink nozzle row 44B is L1. Also, the transport direction lengths L2 of the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B are half the transport direction length L1 of the nozzle row 44 (processing liquid nozzle row 44A and ink nozzle row 44B). As shown in the upper part of Figure 9, under normal conditions (before changing the drying period), the transport direction length L10 between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B corresponds to the transport volume of four transport operations. As shown in the upper part of Figure 9, the controller 70 alternately repeats a pass with a gap L10 between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B, and a transport operation with a transport volume L3. As a result, under normal conditions, multi-pass printing as shown in Figure 8 is performed, and a drying period equivalent to four passes (passes 5 to 8) can be provided.

[0048] Figure 10 is an explanatory diagram of a dot formation method when the temperature is high or the humidity is low. In other words, Figure 10 is an explanatory diagram of a dot formation method for shortening the drying period.

[0049] As shown in the lower left of Figure 9 and in Figure 10, when the temperature is high or the humidity is low (when the measurement result of the sensor 61 is higher than the first reference temperature, or when the measurement result of the sensor 61 is lower than the first reference humidity), the controller 70 narrows the distance between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B. For example, the controller 70 sets the distance between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B from a length L10 corresponding to the transport volume of four transport operations to a length L11 corresponding to the transport volume of three transport operations. On the other hand, the controller 70 sets the length of the transport direction of the processing liquid nozzle row 44A and the ink nozzle row 44B to L2 and maintains it at the same length as under normal conditions. The controller 70 also sets the transport volume during transport operations to L3 (approximately 1 / 4 of the length L2) and maintains it at the same transport volume as under normal conditions. Then, as shown in the lower left diagram of Figure 9, the controller 70 alternately repeats a pass with a gap L11 between the working range 46A of the processing liquid nozzle row 44A and the working range 46B of the ink nozzle row 44B, and a transport operation with a transport amount L3. This enables multi-pass printing as shown in Figure 10.

[0050] Focusing on region A1 in Figure 10, after the processing liquid dots are formed in region A1 by pass 4, there is a drying period of three passes (passes 5-7) during which no dots are formed in region A1. After this drying period, ink dots are formed in region A1 by pass 8. Thus, the dot formation method shown in Figure 10 allows for a drying period equivalent to three passes. In other words, the dot formation method shown in Figure 10 has a drying period that is one pass shorter than the dot formation method shown in Figure 8. On the other hand, since the length L2 in the transport direction of the usage area 46A of the processing liquid nozzle row 44A and the usage area 46B of the ink nozzle row 44B are maintained at their normal lengths, or in other words, the transport amount L3 during transport operation is maintained at its normal length, the transport direction lengths of each region (each region A1-A15 in Figures 8 and 10) can be kept the same before and after the change in the drying period, thus suppressing differences in image quality before and after the change in the drying period.

[0051] Furthermore, if the temperature becomes even higher or the humidity becomes even lower, the controller 70 may shorten the distance between the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B to a length L11 or less. This makes it possible to shorten the drying period even further than that of the dot formation method shown in Figure 10.

[0052] Figure 11 is an explanatory diagram of a dot formation method when the temperature is low or the humidity is high. In other words, Figure 11 is an explanatory diagram of a dot formation method for extending the drying period.

[0053] As shown in the lower right diagram of Figure 9 and in Figure 11, when the temperature is low or the humidity is high (when the measurement result of the sensor 61 is lower than the second reference temperature or when the measurement result of the sensor 61 is higher than the second reference humidity), the controller 70 widens the distance between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B. For example, the controller 70 sets the distance between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B from a length L10 corresponding to the transport volume of four transport operations to a length L12 corresponding to the transport volume of five transport operations. On the other hand, the controller 70 sets the length of the transport direction of the ink nozzle row 44B and the processing liquid nozzle row 44A to L2 and maintains it at the same length as under normal conditions. The controller 70 also sets the transport volume during transport operations to L3 (approximately 1 / 4 of the length L2) and maintains it at the same transport volume as under normal conditions. Then, as shown in the lower right diagram of Figure 9, the controller 70 alternately repeats a pass with a gap L12 between the working range 46A of the processing liquid nozzle row 44A and the working range 46B of the ink nozzle row 44B, and a transport operation with a transport amount L3. This enables multi-pass printing as shown in Figure 11.

[0054] Focusing on region A1 in Figure 11, after the processing liquid dots are formed in region A1 by pass 4, there is a drying period of five passes (passes 5-9) during which no dots are formed in region A1. After this drying period, ink dots are formed in region A1 by pass 10. Thus, the dot formation method shown in Figure 11 allows for a drying period equivalent to five passes. In other words, the dot formation method shown in Figure 11 has a drying period that is one pass longer than the dot formation method shown in Figure 8. On the other hand, since the length L2 in the transport direction of the usage area 46A of the processing liquid nozzle row 44A and the usage area 46B of the ink nozzle row 44B are maintained at their normal lengths, or in other words, the transport amount L3 during transport operation is maintained at its normal length, the transport direction lengths of each region (each region A1-A15 in Figures 8 and 11) can be kept the same before and after the change in the drying period, thus suppressing differences in image quality before and after the change in the drying period.

[0055] Furthermore, if the temperature becomes even lower or the humidity becomes even higher, the controller 70 may make the distance between the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B longer than the length L12. This allows for an even longer drying period than the dot formation method shown in Figure 11.

[0056] In the above description, the controller 70 changes the distance between the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B by changing the operating range 46A of the processing liquid nozzle row 44A. However, it is also possible to change the distance between the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B by changing the operating range 46B of the ink nozzle row 44B. In this case as well, when adjusting the distance between the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B, by maintaining the respective lengths in the transport direction of the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B, in other words, by maintaining the transport amount during transport operation, the length in the transport direction of each region (each region A1 to A15 in Figure 8) before and after the change in the drying period can be made the same, thereby suppressing differences in image quality.

[0057] <Regarding adjustments to the drying time during printing> In the printing methods shown in Figures 8, 10, and 11, the controller 70 acquires the measurement results from the sensor 61 before printing starts and sets the interval between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B based on the measurement results from the sensor 61. Therefore, in the printing methods shown in Figures 8, 10, and 11, the interval between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B is constant in each print pass. Alternatively, the measurement results from the sensor 61 may be acquired during printing, and the interval between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B may be changed during printing based on the measurement results from the sensor 61. Similarly, if a user inputs at least one of the temperature and humidity information to the printing device 1 by operating an input unit (such as an input screen or input button) during printing, the interval between the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B may be changed based on the temperature and humidity information input to the input unit (corresponding to the acquisition unit 60). Similarly, if the controller 70 controls the temperature of the heating device 50 (heater 51 or blower 52) during printing, the signal acquisition unit (corresponding to the acquisition unit 60) may acquire the control signal output from the controller 70 to the heating device 50, and the interval between the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B may be changed based on the temperature information indicated by the control signal.

[0058] Figure 12 is an explanatory diagram of a dot formation method when the temperature becomes high or the humidity becomes low during printing. In other words, Figure 12 is an explanatory diagram of a dot formation method to shorten the drying period during printing.

[0059] Paths 1 to 15 shown in Figure 12 are the same as paths 1 to 15 shown in Figure 8. Here, before path 16, we assume that the measurement result of sensor 61 has risen above the first reference temperature, or that the measurement result of sensor 61 has fallen below the first reference humidity.

[0060] If the measurement result of the sensor 61 is higher than the first reference temperature, or if the measurement result of the sensor 61 is lower than the first reference humidity, the controller 70 will narrow the distance between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B. However, if, in pass 16, as shown in the lower left diagram of Figure 9, the distance between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B is set to a length L11 that corresponds to the transport amount of three transport operations, then, even though all the processing liquid dots have already been formed in area A12 by four passes (passes 12 to 15), processing liquid will be applied to area A12 in pass 16, resulting in an excessive amount of processing liquid being applied to area A12.

[0061] Therefore, before performing the pass that changes the usable range 46A of the processing liquid nozzle row 44A (pass 20 in Figure 12), as shown in the lower left diagram of Figure 9, the controller 70 temporarily performs transition passes (passes 16-19 in Figure 12). In the transition passes, the controller 70 temporarily changes the length of the usable range 46 of the nozzle row 44 in the transport direction from the normal length L2 to length L2'. Specifically, in the transition passes, the controller 70 changes the 1 / 4 range on the downstream side of the usable range 46A of the processing liquid nozzle row 44A shown in the lower left diagram of Figure 9 (the range corresponding to the transport volume of one transport operation; the range marked with an "x" in Figure 12) to an unused range. In the transition passes, the distance between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B becomes L10, the same as in the normal state, which corresponds to the transport volume of four transport operations. In the transition paths (paths 16-19 in Figure 12), the length L2' of the transport direction of the usable area 46A of the processing liquid nozzle row 44A is shorter than the length L2 of the transport direction of the usable area 46A of the processing liquid nozzle row 44A in paths other than the transition paths. Therefore, it is possible to suppress the application of excessive processing liquid to the medium M.

[0062] After repeating this transition path and transport operation four times, the controller 70 sets the distance between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B to a length L11, which corresponds to the transport amount for three transport operations, as shown in the lower left diagram of Figure 9. The controller 70 also returns the length of the usable area 46A of the processing liquid nozzle row 44A in the transport direction to L2, as shown in the lower left diagram of Figure 9. As a result, the length L2 of the usable area 46A of the processing liquid nozzle row 44A in the transport direction in the paths after the transition path (paths from path 20 onwards) is maintained at the length L2 of the usable area 46A of the processing liquid nozzle row 44A in the transport direction in the paths before the transition path (paths before path 15 in Figure 12). The controller 70 then alternately repeats paths with a distance L11 between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B (see path 20 in Figure 12) and the transport operation, as shown in the lower left diagram of Figure 9. This allows for a shorter drying period and enables adjustment to a drying period suitable for the temperature and humidity.

[0063] Even when a temporary transition path (paths 16-19 in Figure 12) is performed, the controller 70 sets the transport volume during transport operation to L3 (approximately 1 / 4 of the length L2) and maintains the same transport volume as under normal conditions. This makes it possible to keep the transport direction length of each region (each region A1-A19 in Figure 12) the same before and after the change in the drying period, thereby suppressing differences in image quality before and after the change in the drying period.

[0064] Figure 13 is an explanatory diagram of a dot formation method when the temperature drops or the humidity increases during printing. In other words, Figure 13 is an explanatory diagram of a dot formation method to extend the drying period during printing.

[0065] Paths 1 to 15 shown in Figure 13 are the same as paths 1 to 15 shown in Figure 8. Here, before path 16, we assume that the measurement result of sensor 61 has fallen below the second reference temperature, or that the measurement result of sensor 61 has risen above the second reference humidity.

[0066] If the measurement result from the sensor 61 is lower than the second reference temperature, or if the measurement result from the sensor 61 is higher than the second reference humidity, the controller 70 will widen the gap between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B. However, if the gap between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B is set to a length L12, which corresponds to the amount of transported material for five transport operations, as shown in the lower right diagram of Figure 9 in pass 16, the amount of processing liquid applied to area A13 will be insufficient.

[0067] Therefore, the controller 70 temporarily performs transition passes (passes 16-19 in Figure 13) before performing a pass (pass 20 in Figure 13) that changes the usage range 46A of the processing liquid nozzle row 44A, as shown in the lower right diagram of Figure 9. In the transition path, the controller 70 temporarily changes the length of the usable range 46 of the nozzle row 44 in the transport direction from the normal length L2 to length L2''. Specifically, in the transition path, the controller 70 changes the usable range 46A to the upper 1 / 4 of the unused range downstream of the processing liquid nozzle row 44A shown in the lower right diagram of Figure 9 (the range corresponding to the transport volume of one transport operation; the darkly hatched area in Figure 13). In the transition path, the distance between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B becomes length L10, which corresponds to the transport volume of four transport operations, as in the normal state. Since the length L2'' of the usable range 46A of the processing liquid nozzle row 44A in the transport direction in the transition path (paths 16 to 19 in Figure 13) is longer than the length L2 of the usable range 46A before the transition path, it is possible to supplement the processing liquid applied to the medium M (it is possible to suppress a shortage in the amount of processing liquid applied).

[0068] After repeating this transition path and transport operation four times, the controller 70 sets the distance between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B to a length L12, which corresponds to the transport volume of five transport operations, as shown in the lower right diagram of Figure 9. The controller 70 also returns the length of the usable area 46A of the processing liquid nozzle row 44A in the transport direction to L2, as shown in the lower right diagram of Figure 9. As a result, the length L2 of the usable area 46A of the processing liquid nozzle row 44A in the transport direction in the paths after the transition path (paths from path 20 onwards) is maintained at the length L2 of the usable area 46A of the processing liquid nozzle row 44A in the transport direction in the paths before the transition path (paths before path 15 in Figure 13). The controller 70 then alternately repeats paths with a distance L12 between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B (see path 20 in Figure 12) and the transport operation, as shown in the lower right diagram of Figure 9. This allows for a longer drying period, enabling adjustment to suit the temperature and humidity conditions.

[0069] Even when a temporary transition path (paths 16-19 in Figure 13) is performed, the controller 70 sets the transport volume during transport operation to L3 (approximately 1 / 4 of the length L2) and maintains the same transport volume as under normal conditions. This makes it possible to keep the transport direction length of each region (each region A1-A19 in Figure 13) the same before and after the change in the drying period, thereby suppressing differences in image quality before and after the change in the drying period.

[0070] Incidentally, when changing the interval between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B during printing, the usable range 46B of the ink nozzle row 44B may be changed instead of the usable range 46A of the processing liquid nozzle row 44A. However, changing the usable range 46B of the ink nozzle row 44B during printing may result in uneven image quality of the ink image 91B. For this reason, as shown in Figures 9 to 11, when changing the interval between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B during printing, it is desirable for the controller 70 to change the interval between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B by changing the usable range 46A of the processing liquid nozzle row 44A.

[0071] <Variation> Figures 14A and 14B are explanatory diagrams of the first modified example. Figure 14A is an explanatory diagram of the dot formation method under normal conditions. Figure 14B is an explanatory diagram of the dot formation method when the temperature is high or the humidity is low. Note that the explanation of the dot formation method when the temperature is low or the humidity is high is omitted here. In the first modified example, the length in the transport direction of the usable area 46A of the processing liquid nozzle row 44A and the length in the transport direction of the usable area 46B of the ink nozzle row 44B are different. Even if the length in the transport direction of the usable area 46A of the processing liquid nozzle row 44A and the length in the transport direction of the usable area 46B of the ink nozzle row 44B are not the same, it is possible to adjust the drying period by adjusting the distance between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B. Furthermore, in the first modified example as well, when adjusting the distance between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B, by maintaining the respective lengths in the transport direction of the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B, in other words, by maintaining the transport amount during transport operation, it is possible to make the length in the transport direction of each region (each region A1 to A15 in Figure 8) the same before and after changing the drying period, thereby suppressing differences in image quality. Furthermore, in the first modified example, the processing liquid image 91A is formed by two-pass printing, and the ink image 91B is formed by four-pass printing. As shown in Figure 2, the number of processing liquid nozzle rows 44A (4) is greater than the number of ink nozzle rows 44B (1 for each color), so the number of passes required to complete the processing liquid image 91A can be less than the number of passes required to complete the ink image 91B. As shown in this first modified example, even when the processing liquid image 91A and the ink image 91B are formed by multi-pass printing, the number of passes required to complete the processing liquid image 91A in each region of the medium M may be different from the number of passes required to complete the ink image 91B in each region of the medium M.

[0072] Figures 15A and 15B are explanatory diagrams of a second modified example. Figure 15A is an explanatory diagram of the dot formation method under normal conditions. Figure 15B is an explanatory diagram of the dot formation method when the temperature is high or the humidity is low. In the second modified example shown in Figures 15A and 15B, the dots to be formed in each region are completed in a single pass. As shown in this second modified example, even without multi-pass printing, the drying period can be adjusted by changing the interval L10 between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B. Furthermore, in the second modified example as well, when adjusting the interval between the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B, by maintaining the respective transport lengths of the usable area 46A of the processing liquid nozzle row 44A and the usable area 46B of the ink nozzle row 44B, in other words, by maintaining the transport amount during transport operation, the transport length of each region (each region A1 to A15 in Figure 8) can be made the same before and after changing the drying period, thereby suppressing differences in image quality.

[0073] Figures 16A and 16B are explanatory diagrams of a third modified example. Figure 16A is an explanatory diagram of the configuration of the head unit 40. Figure 16B is an explanatory diagram of the usage range 46A of the processing liquid nozzle row 44A and the usage range 46B of the ink nozzle row 44B. In the third modified example, the processing liquid nozzle row 44A and the ink nozzle row 44B are aligned in the scanning direction. In this way, even if the processing liquid nozzle row 44A is not positioned upstream of the ink nozzle row 44B in the transport direction, the drying period can be adjusted by changing the interval L10 between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B. However, as can be understood by comparing Figure 9 and Figure 16B, positioning the processing liquid nozzle row 44A upstream of the ink nozzle row 44B in the transport direction, as shown in Figure 9, reduces the number of unused nozzles and allows for more effective utilization of the nozzles. Note that when the processing liquid nozzle row 44A is positioned upstream of the ink nozzle row 44B in the transport direction, some of the processing liquid nozzles 45A on the downstream side of the processing liquid nozzle row 44A and some of the ink nozzles 45B on the upstream side of the ink nozzle row 44B in the transport direction may be aligned in the scanning direction.

[0074] In the above description, the controller 70 controlled the unused ranges of the processing liquid nozzle row 44A and the ink nozzle row 44B, thereby changing the interval L10 between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B. However, the method for changing the interval L10 between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B is not limited to this. For example, at least one of the processing liquid head 41A and the ink head 41B, head 41, may be configured to move in the transport direction, and the controller 70 may control the drive unit based on the measurement results of the sensor 61 to change the position of the head 41 in the transport direction, thereby changing the interval L10 between the usable range 46A of the processing liquid nozzle row 44A and the usable range 46B of the ink nozzle row 44B. Even in this way, the number of unused nozzles can be reduced, and the nozzles can be used effectively. However, controlling the unused ranges of the processing liquid nozzle row 44A and the ink nozzle row 44B is preferable to configuring the head 41 to be movable in the transport direction, as this simplifies the structure of the printing apparatus 1.

[0075] <Another variation 1> In the above description, the printing apparatus 1 is provided with an acquisition unit 60 that acquires information on at least one of temperature and humidity. However, the printing apparatus 1 does not necessarily have to be provided with an acquisition unit 60 that acquires information on at least one of temperature and humidity. For example, instead of based on information on at least one of temperature and humidity, the controller 70 may change the distance in the transport direction between the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B so that a drying time corresponding to the amount of ink is set based on information on the amount of ink ejected onto the medium M. In this case as well, the drying period can be adjusted to an appropriate length. Furthermore, even in this case, when adjusting the spacing between the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B, by maintaining the respective lengths in the transport direction of the operating range 46A of the processing liquid nozzle row 44A and the operating range 46B of the ink nozzle row 44B, in other words, by maintaining the transport amount during transport operation, the transport direction lengths of each region (each region A1 to A15 in Figure 8) can be made the same before and after the change in the drying period, thereby suppressing differences in image quality.

[0076] ===Another Embodiment=== In the first embodiment described above, the first head 41A is a processing liquid head that discharges processing liquid (corresponding to the first liquid), and the second head 41B is an ink head that discharges ink (corresponding to the second liquid). However, the first head 41A does not have to be a processing liquid head, and the second head 41B does not have to be an ink head. In other words, the first liquid does not have to be a processing liquid, and the second liquid does not have to be ink (color ink). For example, the first head 41A may be an ink head that ejects white ink (corresponding to the first liquid), and the second head 41B may be an ink head that ejects color ink (corresponding to the second liquid). In this case, a color image formed with color ink will be formed on top of a background image formed with white ink. Alternatively, the first head 41A may be an ink head that ejects color ink (corresponding to the first liquid), and the second head 41B may be a coating head that ejects a coating liquid (corresponding to the second liquid). In this case, a coating image (coating layer) formed with the coating liquid will be formed on top of the ink image formed with the ink.

[0077] In the first embodiment described above, the first moving unit 20 moves the medium M in the transport direction (corresponding to the first direction), but the first moving unit 20 does not have to move the medium M in the first direction (transport direction). For example, the first moving unit 20 may move the second moving unit 30 (carriage unit) in the first direction, thereby moving the head 41 (41A, 41B) and the medium M in the first direction (this may also be a printing device known as a gantry type). In such a gantry type printing device, a first movement operation in which the first moving unit moves the second moving unit (carriage unit) in the first direction, and a second movement operation in which the second moving unit moves the head in the second direction (corresponding to the aforementioned path) are repeated alternately to form dots on the medium M. In this case, during the first movement operation, the first moving unit 20 moves the second moving unit (carriage unit) toward the upstream side of the first movement direction. Furthermore, even in the case of a gantry-type printing apparatus, the lengths of the working ranges 46A of the first nozzle row 44A and 46B of the second nozzle row 44B in the first direction (corresponding to L2 mentioned above) are maintained, and the amount of movement (corresponding to L3) when the first moving unit 20 moves the media M and the nozzle row 44 relative to each other in the first direction is maintained, while changing the distance in the first direction between the working ranges 46A of the first nozzle row 44A and 46B of the second nozzle row 44B (corresponding to the distance L10 mentioned above) (see Figure 9). This makes it possible to adjust the drying period to an appropriate length while suppressing changes in image quality.

[0078] ===Summary=== The above-described printing apparatus 1 comprises a first head 41A, a second head 41B, a first moving unit 20, and a second moving unit 30. The first head 41A has a first nozzle row 44A (e.g., a processing liquid nozzle row) in which first nozzles 45A (e.g., processing liquid nozzles) capable of ejecting a first liquid (e.g., processing liquid) are arranged in a first direction (e.g., the transport direction) (see Figure 2 or Figure 16A). The second head 41B (e.g., an ink head) has a second nozzle row 44B in which a plurality of second nozzles 45B capable of ejecting a second liquid (e.g., ink) to be ejected onto the first liquid are arranged in a first direction (see Figure 2 or Figure 16A). The first moving unit 20 moves the heads 41 (first head 41A and second head 41B) and the medium M relative to each other in a first direction. The second moving unit 30 moves the heads 41 (first head 41A and second head 41B) in a second direction intersecting the first direction. In this embodiment, the distance between the working range 46A of the first nozzle row 44A and the working range 46B of the second nozzle row 44B in the first direction (for example, the distance L10) is changed while maintaining the respective lengths in the first direction of the working range 46A of the first nozzle row 44A and the working range 46B of the second nozzle row 44B (see Figure 9). This makes it possible to adjust the drying period to an appropriate length while suppressing changes in image quality.

[0079] In the printing apparatus 1 described above, it is preferable that the first liquid is a processing liquid. This allows the second liquid, which is dispensed onto the first liquid, to be suitably fixed to the medium, thereby improving image quality.

[0080] The printing apparatus 1 described above further includes an acquisition unit 60 that acquires information on at least one of temperature and humidity. Based on the information acquired by the acquisition unit 60 (information on at least one of temperature and humidity), the spacing between the working range 46A of the first nozzle row 44A and the working range 46B of the second nozzle row 44B in the first direction is changed (see Figure 9). This makes it possible to adjust the drying period to an appropriate length.

[0081] Furthermore, the aforementioned acquisition unit 60 is a sensor 61 that measures at least one of temperature and humidity. Based on the temperature and humidity measurement results from the sensor 61, the spacing in the first direction between the operating range 46A of the first nozzle row 44A and the operating range 46B of the second nozzle row 44B is changed (see Figure 9). This allows the drying period to be adjusted to an appropriate length.

[0082] Furthermore, the aforementioned acquisition unit 60 may acquire information entered by the user (at least one of temperature and humidity information). This eliminates the need for a sensor 61, thereby simplifying the configuration of the printing device 1.

[0083] Furthermore, the aforementioned acquisition unit 60 may acquire information on at least one of temperature and humidity by acquiring control signals that control the heating device 50 (for example, a heater 51 or a blower 52). This allows the drying time to be adjusted to a length suitable for the drying environment regulated by the heating device 50.

[0084] Furthermore, in the above-described printing apparatus 1, it is desirable to narrow the distance in the first direction between the operating range 46A of the first nozzle row 44A and the operating range 46B of the second nozzle row 44B as the temperature acquired by the acquisition unit 60 increases or the humidity acquired by the acquisition unit 60 decreases. This allows for a shorter drying period when the processing liquid is prone to drying.

[0085] Furthermore, in the above-described printing apparatus 1, it is desirable to widen the distance in the first direction between the operating range 46A of the first nozzle row 44A and the operating range 46B of the second nozzle row 44B as the temperature acquired by the acquisition unit 60 decreases or the humidity acquired by the acquisition unit 60 increases. This allows for a longer drying period when the processing liquid is difficult to dry.

[0086] Furthermore, it is desirable to perform multi-pass printing with the above-described printing apparatus 1. That is, in the above-described printing apparatus 1, it is desirable to complete the dots to be formed in an area of ​​the medium M with a width corresponding to the amount of movement of one first movement operation by the first movement unit 20 (corresponding to L3 mentioned above) by performing multiple second movement operations by the second movement unit 30 (corresponding to the aforementioned passes). This improves the image quality compared to a printing method (one-pass printing) in which the dots to be formed are completed in one second movement operation (corresponding to a single pass).

[0087] Furthermore, in the above-described printing apparatus, it is desirable to change the distance in the first direction between the operating range 46A of the first nozzle row 44A and the operating range 46B of the second nozzle row 44B during printing, based on the information acquired by the acquisition unit 60 (at least one of temperature and humidity information) (see Figures 12 and 13). This makes it possible to adjust the drying period to an appropriate length in response to changes in the environment during printing.

[0088] Furthermore, when changing the spacing during printing, it is desirable to temporarily change the length of the usable area 46A of the first nozzle row 44A in the first direction, and then return the length of the usable area 46A of the first nozzle row 44A to its original length (see paths 16-19 in Figures 12 and 13). This helps to suppress any excess or deficiency of the first liquid applied to the medium M.

[0089] When the first liquid is a processing liquid and the first head 41A is a processing liquid head, it is desirable that the first nozzle row 44A (in this case, the processing liquid nozzle row 44A) be located upstream of the second nozzle row 44B (in this case, the ink nozzle row) in the first direction (see Figure 2). This reduces the number of unused nozzles and allows for more effective use of the nozzles compared to the case where the first nozzle row 44A and the second nozzle row 44B are aligned in the second direction, as shown in Figure 16A.

[0090] Furthermore, the printing apparatus 1 described above maintains the amount of movement (corresponding to L3 mentioned above) when the first moving unit 20 moves the head 41 (first head 41A and second head 41B) and the medium M relative to each other in the first direction, while changing the distance (for example, the distance L10) between the working range 46A of the first nozzle row 44A and the working range 46B of the second nozzle row 44B in the first direction (see Figure 9). This makes it possible to adjust the drying period to an appropriate length while suppressing changes in image quality.

[0091] ===Other Embodiments=== The above embodiments are presented as examples and do not limit the scope of the invention. The above configurations can be combined as appropriate, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The above embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0092] 1 printing device, 20 First mobile unit (transport unit), 21 Transport roller, 22 Transport motors, 30 Second mobile unit (carriage unit), 31 Carriage, 32 carriage motors, 40 head units, 41 heads, 41A First head (e.g., ink head), 41B Second head (e.g., processing fluid head), 42 Head drive unit, 44 nozzle rows, 44A First nozzle row (e.g., processing liquid nozzle row), 44B Second nozzle row (e.g., ink nozzle row), 45 nozzles, 45A First nozzle (e.g., processing liquid nozzle), 45B Second nozzle (e.g., ink nozzle), 46. ​​Scope of use, 50 Heating device, 51 Heater, 52 Blower, 60 Acquisition unit, 61 Sensor, 70 controllers, 91A First image (e.g., processing solution image), 91B Second image (e.g., ink image), M medium

Claims

1. A first head having a first nozzle row in which a plurality of first nozzles capable of dispensing a first liquid are arranged in a first direction, A second head having a second nozzle row in which a plurality of second nozzles capable of discharging a second liquid onto the first liquid are arranged in the first direction, A first moving unit that moves the first head and the second head and the medium relative to each other in the first direction, A second moving unit moves the first head and the second head in a second direction intersecting the first direction, Equipped with, The distance between the operating range of the first nozzle row and the operating range of the second nozzle row in the first direction is changed by arranging unused nozzles between the operating range of the first nozzle row and the operating range of the second nozzle row in the first direction, while maintaining the respective lengths of the operating range of the first nozzle row and the operating range of the second nozzle row in the first direction. Printing device.

2. A printing apparatus according to claim 1, The first liquid is a processing liquid. Printing device.

3. A printing apparatus according to claim 1 or 2, The system further includes an acquisition unit that acquires information on at least one of temperature and humidity, Based on the above information, change the above interval. Printing device.

4. A printing apparatus according to claim 3, The acquisition unit is a sensor that measures at least one of the temperature and the humidity. Printing device.

5. A printing apparatus according to claim 3, The acquisition unit acquires the information entered by the user. Printing device.

6. A printing apparatus according to claim 3, The acquisition unit acquires the information by acquiring a control signal for controlling the heating device. Printing device.

7. A printing apparatus according to claim 3, The higher the temperature acquired by the acquisition unit, or the lower the humidity acquired by the acquisition unit, the narrower the interval. Printing device.

8. A printing apparatus according to claim 3, The lower the temperature acquired by the acquisition unit, or the higher the humidity acquired by the acquisition unit, the wider the gap. Printing device.

9. A printing apparatus according to claim 1 or 2, A printing apparatus that completes the formation of dots in a region of the medium having a width corresponding to the amount of movement of one first movement operation by the first movement unit by performing multiple second movement operations by the second movement unit.

10. A first head having a first nozzle row in which a plurality of first nozzles capable of discharging a first liquid are arranged in a first direction, A second head having a second nozzle row in which a plurality of second nozzles capable of discharging a second liquid onto the first liquid are arranged in the first direction, A first moving unit that moves the first head and the second head and the medium relative to each other in the first direction, A second moving unit moves the first head and the second head in a second direction intersecting the first direction, Equipped with, While maintaining the respective lengths in the first direction of the operating ranges of the first and second nozzle rows, the distance between the operating ranges of the first and second nozzle rows in the first direction is changed during printing. Printing device.

11. A printing apparatus according to claim 10, When changing the interval during printing, the length of the usable range of the first nozzle row in the first direction is temporarily changed, and then the length of the usable range of the first nozzle row in the first direction is returned to the length before the interval was changed. Printing device.

12. A printing apparatus according to claim 1 or 2, The first nozzle row is located upstream of the second nozzle row in the first direction. Printing device.

13. A first head having a first nozzle row in which a plurality of first nozzles capable of dispensing a first liquid are arranged in a first direction, A second head having a second nozzle row in which a plurality of second nozzles capable of discharging a second liquid onto the first liquid are arranged in the first direction, A first moving unit that moves the first head and the second head and the medium relative to each other in the first direction, A second moving unit moves the first head and the second head in a second direction intersecting the first direction, Equipped with, While maintaining the amount of movement when the first moving unit moves the first head and the second head relative to the medium in the first direction, the distance between the operating range of the first nozzle row and the operating range of the second nozzle row in the first direction is changed by arranging unused nozzles between the operating range of the first nozzle row and the operating range of the second nozzle row in the first direction. Printing device.

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