JP7248945B2 - controller and computer program - Google Patents

Description

The present specification relates to control processing for printing by causing a print execution unit to perform partial printing and sub-scanning multiple times, in which ink is ejected while performing main scanning.

2. Description of the Related Art Conventionally, printers that print images by ejecting ink from a print head have been known. In such a printer, for example, when the temperature of the ink is relatively low, the viscosity of the ink is high, so the supply of the ink from the ink container to the print head is likely to be delayed. When the ink supply is delayed, the image quality may be degraded, for example, the printed image may be lighter in color. Patent Literature 1 describes the following technique. A threshold is calculated based on the temperature in the head. The number of continuous ejection dots is calculated from the number of continuous ejections in one scanning print band. If the number of consecutive ejection dots is larger than the threshold, the number of consecutive ejections of the printhead in one printing scan is reduced by increasing the number of passes.

JP 2004-066550 A

However, when the number of passes is increased, there is room for improvement in terms of the order of overlapping of inks and the colors to be printed.

This specification discloses a technique capable of suppressing color deviation in printing.

The technology disclosed in this specification can be implemented as the following application examples.

[Application Example 1] A print head having L nozzle groups for ejecting L types of ink (L is an integer equal to or greater than 2) and arranged side by side in the main scanning direction an ink supply unit for supplying the L types of ink to the print head; a main scanning unit for performing a main scan for moving the print head along the main scanning direction with respect to the print medium; a sub-scanning unit that executes sub-scanning to move the print medium along a sub-scanning direction that intersects with the main scanning direction; By executing partial printing in which ink is ejected to the print head while causing the main scanning unit to perform the main scanning and causing the sub-scanning unit to perform the sub-scanning a plurality of times, the print execution unit said control device for printing an image, wherein in said partial printing a supply condition is satisfied indicating that supply of at least one type of ink from said ink supply to said print head may be delayed; a determination unit that determines each of the plurality of band images that are included in the image to be printed and are arranged in the sub-scanning direction; a first print processing unit that causes the print execution unit to print the band image by causing the print execution unit to print; and N times (N is an integer of 2 or more) when the supply condition is satisfied. a second print processing unit that causes the print execution unit to print the band image by causing the print execution unit to execute a multiple-part print process including the partial print, wherein The condition is that the target ink for which the supply may be delayed is the first end ink, which is the ink of the first end nozzle group located at one end in the main scanning direction among the L nozzle groups. causing the print execution unit to execute a first multi-portion print process using the first end ink as the first target ink in a first case where a specific condition including a first condition is satisfied, and The first multiple-portion printing process is the first partial printing, and the main scanning moves the print head relative to the print medium in a direction in which the first ink of interest is stacked in order L. is performed by the main scanning unit, and the partial printing in which the L types of ink are ejected to the print head, and the second partial printing in which L−1 types of ink other than the first ink of interest and partial printing that causes only the first ink of interest to be ejected to the print head without ejecting to the print head.

According to this configuration, if the specific condition including the supply condition and the first condition that the target ink determined that the supply may be delayed is the first end ink of the first end nozzle row, band Since the ejection of the first end ink for printing the image is distributed over a plurality of partial printings, delays in the supply of the first end ink can be suppressed. Furthermore, in the first partial printing, while main scanning is performed to move the print head with respect to the print medium in a direction in which the first end ink stacking order is L, L types of ink are ejected, and the second printing is performed. In the partial printing of , only the first end ink is ejected without ejecting the L−1 kinds of ink other than the first end ink. It is possible to suppress the occurrence of a plurality of portions in which the order of overlapping of the inks is different from each other. Therefore, it is possible to suppress the misalignment of printed colors.
[Application example 2]
The control device according to Application Example 1,
The second print processing unit controls the supply condition and the target ink determined to be delayed in supply to a second end nozzle located at the end on the other side in the main scanning direction among the L nozzle groups. a second multi-part printing using said second-end ink as a second ink of interest in a second case where certain conditions are satisfied including: a second condition that it is a second-end ink that is an ink of the group; cause the print execution unit to execute processing;
The second multiple-portion printing process includes:
the first partial printing, in which only the second ink of interest is ejected to the print head without ejecting L-1 kinds of inks other than the second ink of interest to the print head; and,
In the second partial printing, causing the main scanning unit to perform the main scanning for moving the print head relative to the printing medium in a direction in which the second ink of interest is superimposed first. , partial printing in which the L types of ink are ejected to the print head;
a controller, including
[Application Example 3]
The control device according to Application Example 2,
The second print processing unit determines that the main scanning direction in the first partial printing in the second case is different from the main scanning direction in the first partial printing in the first case. causing the print execution unit to execute the first partial printing in the first case and the first partial printing in the second case in opposite directions;
Control device.
[Application example 4]
The control device according to Application Example 3,
The second print processing unit
specifying the order of superimposition of the L types of ink by the one-time partial printing for the band of interest performed when the supply condition is not satisfied for the band of interest image;
For the band image of interest, the first condition satisfying specific conditions including the supply condition, the first condition, and the condition that the order of the ink at the first end in the overlapping order of the inks is L is satisfied. , causing the print execution unit to execute the first multi-portion print process using the first end ink as the first ink of interest;
If the band image of interest satisfies a specific condition including the supply condition, the first condition, and the condition that the order of the first end ink in the order of overlapping of the inks is first, then the causing the print execution unit to execute the second multiple-portion printing process using the first end ink as the second ink of interest;
With respect to the band image of interest, the second condition satisfies a specific condition including the supply condition, the second condition, and the condition that the order of the second end ink in the overlapping order of the inks is first. , causing the print execution unit to execute the second multiple-portion printing process using the second end ink as the second ink of interest;
If the band image of interest satisfies specific conditions including the supply condition, the second condition, and the condition that the order of the ink at the second end in the overlapping order of the inks is L, then the causing the print execution unit to execute the first multi-portion print process using the second end ink as the first ink of interest;
Control device.

[Application Example 5 ] A print head having L nozzle groups for ejecting L types of ink (L is an integer equal to or greater than 2) and arranged side by side in the main scanning direction an ink supply unit for supplying the L types of ink to the print head; a main scanning unit for performing a main scan for moving the print head along the main scanning direction with respect to the print medium; a sub-scanning unit that executes sub-scanning to move the print medium along a sub-scanning direction that intersects with the main scanning direction; By executing partial printing in which ink is ejected to the print head while causing the main scanning unit to perform the main scanning and causing the sub-scanning unit to perform the sub-scanning a plurality of times, the print execution unit said control device for printing an image, wherein in said partial printing a supply condition is satisfied indicating that supply of at least one type of ink from said ink supply to said print head may be delayed; a determination unit that determines each of the plurality of band images that are included in the image to be printed and are arranged in the sub-scanning direction; a first print processing unit that causes the print execution unit to print the band image by causing the print execution unit to print; and N times (N is an integer of 2 or more) when the supply condition is satisfied. a second print processing unit that causes the print execution unit to print the band image by causing the print execution unit to execute a multiple-part print process including the partial print, wherein a condition that the target ink for which the supply may be delayed is the end ink that is the ink of the end nozzle group located at one end in the main scanning direction among the L nozzle groups; and causing the print execution unit to execute a multiple-portion printing process using the end ink as the target ink, wherein the multiple-portion printing process is the first partial printing, Partial printing in which only the ink of interest is ejected to the print head without ejecting L-1 types of ink other than the ink of interest to the print head, and a second partial printing in which the ink of interest is overlapped. Partial printing in which the L types of ink are ejected to the print head while causing the main scanning unit to perform the main scan in which the print head is moved relative to the print medium in the first direction. including, a controller.

According to this configuration, when specific conditions including the supply condition and the condition that the target ink determined to be delayed in supply is the end ink of the end nozzle row, printing of the band image is performed. Since the ejection of the edge ink is distributed over a plurality of partial printings, the delay in the supply of the edge ink can be suppressed. Furthermore, in the first partial printing, only the edge ink is ejected without ejecting L-1 types of ink other than the edge ink, and in the second partial printing, the stacking order of the edge ink is set to the first. Since L types of ink are ejected while main scanning is performed to move the print head with respect to the print medium, when a band image is printed by N partial printings, the order of stacking of the L types of ink is It is possible to suppress the occurrence of a plurality of portions different from each other. Therefore, it is possible to suppress the misalignment of printed colors.
[Application example 6]
The control device according to any one of Application Examples 1 to 5,
The second print processing unit determines the supply conditions and the target ink determined to be delayed in supply, among the L nozzle groups, positioned inside nozzle groups positioned at both ends in the main scanning direction. the partial printing N times in the same direction of the main scanning, wherein the L types of ink are applied to the print head causing the print execution unit to execute the N partial printings to be ejected to
Control device.
[Application example 7]
The control device according to any one of application examples 1 to 6,
In the second partial printing of the multiple-part printing process, the second print processing unit does not eject the target ink to the pixel positions where the target ink was ejected in the first partial printing, and 1 ejecting the target ink to pixel positions where the target ink was not ejected in the partial printing of the second time;
Control device.
[Application example 8]
The control device according to Application Example 7,
The second print processing unit refers to a predetermined mask pattern indicating pixel positions at which the target ink can be ejected in each of the N partial prints, and performs the target ink in each of the N partial prints. identifying pixel positions where ink should be ejected;
Control device.
[Application example 9]
The control device according to any one of Application Examples 1 to 8,
The ink of the nozzle group positioned at one end in the main scanning direction among the L nozzle groups is black ink.
Control device.

The technology disclosed in this specification can be implemented in various forms, for example, a control method and a control device, a printing method and a printing device, a computer for realizing the functions of those methods or devices. It can be implemented in the form of a program, a recording medium recording the computer program (for example, a non-temporary recording medium), or the like.

1 is an explanatory diagram showing an image processing system 1000 of an embodiment; FIG. 4 is a schematic diagram of a print execution unit 400; FIG. 4 is a diagram showing the configuration of a print head 410; FIG. 4A is an explanatory diagram of an example of the operation of the print execution unit 400; FIG. (B) is a schematic diagram showing the first order I1. (C) is a schematic diagram showing the second order I2. 8 is a flowchart showing an example of print data generation processing; 7 is a flowchart illustrating an example of print execution processing; 7 is a flowchart illustrating an example of print execution processing; 7 is a flowchart illustrating an example of print execution processing; 7 is a flowchart illustrating an example of print execution processing; 7 is a flowchart illustrating an example of print execution processing; 3 is an explanatory diagram showing an example of a threshold table 300; FIG. FIG. 11 is a flow chart showing part of a second embodiment of print execution processing; FIG. (A) and (B) are schematic diagrams showing another example of mask data.

A. First example:
A-1. Configuration of Terminal Device 100 and MFP 200:
FIG. 1 is an explanatory diagram showing an image processing system 1000 of the embodiment. The image processing system 1000 includes a terminal device 100 and a multi-function peripheral 200 connected to the terminal device 100 . As will be described later, the MFP 200 has a scanner unit 280 that reads an object such as a document, a print execution unit 400 that prints an image, and a control unit 299 that controls the MFP 200 as a whole. .

The terminal device 100 is a personal computer (for example, desktop computer, tablet computer, etc.). The terminal device 100 has a processor 110 , a storage device 115 , a display section 140 that displays images, an operation section 150 that receives user operations, and a communication interface 170 . These elements are connected to each other via buses. Storage device 115 includes volatile storage device 120 and non-volatile storage device 130 .

The processor 110 is a device that performs data processing, such as a CPU. The volatile memory device 120 is, for example, a DRAM, and the non-volatile memory device 130 is, for example, a flash memory.

The nonvolatile storage device 130 stores a program 132 and color conversion profiles LUT1 and LUT2. The processor 110 implements various functions for controlling the multifunction device 200 by executing the program 132 . Details of the functions realized by the program 132 and the color conversion profiles LUT1 and LUT2 will be described later. The processor 110 temporarily stores various intermediate data used for executing the program 132 in the storage device 115 (eg, either the volatile storage device 120 or the nonvolatile storage device 130). In this embodiment, program 132 is included in a device driver provided by the manufacturer of MFP 200 .

The display unit 140 is a device that displays an image, such as a liquid crystal display. Alternatively, other types of devices for displaying images may be employed, such as LED displays, organic EL displays, and the like. The operation unit 150 is a device that receives an operation by a user, and is, for example, a touch panel that is superimposed on the display unit 140 . Alternatively, other types of user operated devices such as buttons, levers, etc. may be employed. A user can input various instructions to the terminal device 100 by operating the operation unit 150 .

The communication interface 170 is an interface for communicating with other devices (eg, USB interface, wired LAN interface, IEEE802.11 wireless interface). A multi-function device 200 is connected to the communication interface 170 .

The MFP 200 has a control section 299 , a scanner section 280 and a print execution section 400 . The control unit 299 has a processor 210 , a storage device 215 , a display unit 240 that displays images, an operation unit 250 that accepts user operations, and a communication interface 270 . These elements are connected to each other via buses. Storage 215 includes volatile storage 220 and nonvolatile storage 230 .

The processor 210 is a device that performs data processing, such as a CPU. The volatile memory device 220 is, for example, a DRAM, and the non-volatile memory device 230 is, for example, a flash memory.

The nonvolatile storage device 230 stores a program 232 , a threshold table 300 , a replacement frequency table 310 and mask data 321 . The processor 210 implements various functions by executing the program 232 (details will be described later). The processor 210 temporarily stores various intermediate data used for executing the program 232 in a storage device (eg, either the volatile storage device 220 or the nonvolatile storage device 230). In this embodiment, the program 232 , the threshold table 300 , the exchange frequency table 310 , and the mask data 321 are pre-stored in the non-volatile storage device 230 as firmware by the manufacturer of the MFP 200 . The details of the threshold table 300, the number of times of replacement table 310, and the mask data 321 will be described later.

The display unit 240 is a device that displays an image, such as a liquid crystal display. Alternatively, other types of devices for displaying images may be employed, such as LED displays, organic EL displays, and the like. The operation unit 250 is a device that receives an operation by a user, and is, for example, a touch panel overlaid on the display unit 240 . Alternatively, other types of user operated devices such as buttons, levers, etc. may be employed. The user can input various instructions to the MFP 200 by operating the operation unit 250 .

Communication interface 270 is an interface for communicating with other devices. In this embodiment, the communication interface 270 is connected to the communication interface 170 of the terminal device 100 .

The scanner unit 280 optically reads an object such as a document using a photoelectric conversion element such as a CCD or CMOS, thereby generating scan data representing a read image (referred to as a “scan image”). The scan data is, for example, RGB bitmap data representing a color scan image.

The print execution unit 400 is a device that prints an image on paper (an example of a print medium). In this embodiment, the print execution unit 400 includes a print head 410 (also referred to simply as head 410), a head drive unit 420, a main scanning unit 430, a transport unit 440, an ink supply unit 450, an encoder 460, It has a temperature sensor 470 and a control circuit 490 that controls these elements 410 , 420 , 430 , 440 , 450 , 460 , 470 . Although the details will be described later, the print execution unit 400 is an inkjet printing apparatus that uses cyan C, magenta M, yellow Y, and black K inks. Note that the combination of a plurality of types of ink that can be used is not limited to CMYK, and various other combinations (for example, cyan C, magenta M, and yellow Y) can be adopted.

The MFP 200 can cause the print execution unit 400 to print an image using print data supplied from another device (eg, the terminal device 100). Further, the multi-function device 200 can generate print data using image data selected by the user, and cause the print execution unit 400 to print an image using the generated print data. The user can select scan data or image data stored in an external device (for example, a memory card connected to the communication interface 270).

FIG. 2 is a schematic diagram of the print execution unit 400. As shown in FIG. The main scanning section 430 includes a carriage 433 , a sliding shaft 434 , a belt 435 and a plurality of pulleys 436 and 437 . Carriage 433 carries print head 410 . The sliding shaft 434 holds the carriage 433 so as to reciprocate along the main scanning direction (the direction parallel to the Dx axis in FIG. 2). The belt 435 is wound around pulleys 436 and 437 and partially fixed to the carriage 433 . The pulley 436 is rotated by power of a main scanning motor (not shown). When the main scanning motor rotates the pulley 436 , the carriage 433 moves along the sliding shaft 434 . This implements main scanning in which the print head 410 reciprocates along the main scanning direction with respect to the paper PM.

The transport unit 440 transports the paper PM in the transport direction (+Dy direction in FIG. 2) with respect to the print head 410 while holding the paper PM. Here, the upstream side (−Dy side) in the transport direction is also simply called the upstream side, and the downstream side (+Dy side) in the transport direction is also simply called the downstream side. The transport unit 440 is arranged at a position facing the ink ejection surface of the print head 410, and transports the platen PT configured to support the paper PM and the paper PM placed on the platen PT. It comprises an upstream roller 441, a downstream roller 442, a plurality of pressers 445 configured to hold, and a motor (not shown). The upstream roller 441 is arranged upstream of the print head 410 , and the downstream roller 442 is arranged downstream of the print head 410 . The paper PM is supplied from a paper tray (not shown) to the transport section 440 by a paper feed roller (not shown). The paper PM supplied to the transport unit 440 is sandwiched between the platen PT and the upstream roller 441 and transported downstream by the upstream roller 441 . The transported paper PM is sandwiched between the platen PT and the downstream roller 442 and transported downstream by the downstream roller 442 . Each of the pressing portions 445 is an elastic plate configured to press the paper PM on the platen PT toward the platen PT between the upstream roller 441 and the print head 410 . The transport unit 440 transports the paper PM in the transport direction by driving these rollers 441 and 442 with the power of the motor. Hereinafter, the process of moving the paper PM in the transport direction is also referred to as sub-scanning. The transport direction is also called a sub-scanning direction.

The ink supply section 450 supplies ink to the print head 410 . The ink supply section 450 includes a cartridge mounting section 451 , a tube 452 and a buffer tank 453 . A plurality of ink cartridges KC, YC, CC, and MC, which are containers containing ink inside, are detachably attached to the cartridge attachment portion 451, and ink is supplied from these ink cartridges. The cartridge mounting portion 451 is provided with cartridge sensors 454K, 454Y, 454C, and 454M for detecting the ink cartridges KC, YC, CC, and MC, respectively. Cartridge sensors 454K, 454Y, 454C, and 454M provide ON signals indicating that ink cartridges KC, YC, CC, and MC have been detected, and OFF signals indicating that ink cartridges KC, YC, CC, and MC have not been detected. , or The buffer tank 453 is arranged above the print head 410 in the carriage 433 and temporarily stores the ink to be supplied to the print head 410 for each CMYK ink. The tube 452 is a flexible tube serving as an ink flow path that connects the cartridge mounting portion 451 and the buffer tank 453 . Ink in each ink cartridge is supplied to the print head 410 via the cartridge mounting portion 451 , tube 452 and buffer tank 453 . The buffer tank 453 is provided with a filter (not shown) for removing foreign matter mixed in the ink.

FIG. 3 is a diagram showing the configuration of the print head 410 viewed from the -Dz side. As shown in FIG. 3, the nozzle forming surface 411 of the print head 410 is a surface facing the paper PM conveyed by the conveying section 440 (FIG. 2). The nozzle formation surface 411 is formed with a plurality of nozzle arrays composed of a plurality of nozzles NZ, that is, nozzle arrays NC, NM, NY, and NK for ejecting each of the C, M, Y, and K inks described above. Each nozzle row includes a plurality of nozzles NZ. The plurality of nozzles NZ have different positions in the transport direction (+Dy direction) and are arranged at a predetermined nozzle interval NT along the transport direction. The nozzle interval NT is the length in the transport direction between two nozzles NZ adjacent in the transport direction among the plurality of nozzles NZ. Among the nozzles forming these nozzle rows, the nozzle NZ located on the most upstream side (-Dy side) is also called the most upstream nozzle NZu. Further, among these nozzles, the nozzle NZ located on the most downstream side (+Dy side) is called the most downstream nozzle NZd. The length obtained by adding the nozzle interval NT to the length in the transport direction from the most upstream nozzle NZu to the most downstream nozzle NZd is also called a nozzle length D.

The positions of the nozzle rows NC, NM, NY, and NK in the main scanning direction are different from each other, and the positions in the sub-scanning direction overlap each other. In the example of FIG. 3, the nozzle rows NK, NY, NC, and NM are arranged in this order in the +Dx direction.

Each nozzle NZ is connected to the buffer tank 453 (FIG. 2) via an ink channel (not shown) formed inside the print head 410 . Each ink channel is provided with an actuator (not shown; for example, a piezo element, a heater, etc.) for ejecting ink.

The head drive section 420 (FIG. 1) includes an electric circuit that drives each actuator in the print head 410 according to print data during main scanning by the main scanning section 430 . As a result, ink is ejected from the nozzles NZ of the print head 410 onto the paper PM to form dots.

When ink is ejected from the nozzles NZ (FIG. 3) during printing, the amount of ink in the buffer tank 453 (FIG. 2) is reduced by the amount of ink ejected. Due to this negative pressure, ink is supplied from the ink cartridge to the buffer tank 453 via the cartridge mounting portion 451 and the tube 452 . If a large amount of ink is ejected from a plurality of nozzles NZ within a short period of time for printing, a delay in the supply of ink to the buffer tank 453 may occur. When such a delay in ink supply occurs, even if the actuator is driven, ink may not be ejected from the nozzles NZ, or ink may be ejected in a smaller amount than expected. When such a problem occurs, the color of the printed image becomes lighter and the image quality deteriorates.

A delay in the supply of ink is likely to occur when the fluidity of the ink is reduced. For example, the lower the temperature of the print head 410 (hereinafter also referred to as the head temperature), the more likely it is that ink supply will be delayed. The reason for this is that the lower the head temperature, the higher the viscosity of the ink and the lower the fluidity of the ink.

In addition, delays in ink supply are likely to occur as the cumulative amount of ink used increases. The cumulative ink usage is the cumulative usage of ink from the manufacturing of the MFP 200 to the present, and is specified for each ink. As the cumulative amount of ink used increases, the amount of contaminants accumulated in a filter for removing contaminants in the ink increases, so the flow path resistance of the ink increases and the fluidity of the ink decreases. Therefore, an increase in cumulative ink usage can delay the supply of ink.

As will be described later, the print execution process of this embodiment is configured to suppress delays in ink supply.

The encoder 460 (FIGS. 1 and 2) is a device that detects the position of the print head 410 in the main scanning direction, and is a so-called linear encoder. As shown in FIG. 2, encoder 460 includes linear scale 461 and optical sensor 462 . The linear scale 461 is a belt-like member extending in the main scanning direction and fixed inside the housing. The linear scale 461 has light-transmitting portions and light-shielding portions alternately formed along the longitudinal direction. The optical sensor 462 is mounted on the carriage 433 and moves together with the print head 410 during main scanning. The optical sensor 462 includes a light-emitting element that irradiates the linear scale 461 with light and a light-receiving element that receives light transmitted through the linear scale 461 . During main scanning in which the carriage 433 (print head 410 ) moves in the main scanning direction, the optical sensor 462 outputs pulse signals indicating changes in the position of the optical sensor 462 with respect to the linear scale 461 . Since the position of the carriage 433 in the main scanning direction can be obtained based on this pulse signal, the pulse signal can be said to be a position signal indicating the position of the carriage 433 in the main scanning direction. A position signal output from the encoder 460 is supplied to the control circuit 490 and the control section 299 and used for main scanning and control of the print head 410 .

A temperature sensor 470 (FIGS. 1 and 2) is a known temperature sensor including a resistance temperature detector and the like, and is fixed to the print head 410. FIG. Temperature sensor 470 outputs a signal indicative of the temperature of print head 410 .

A-2. Print overview:
The print execution unit 400 causes the main scanning unit 430 to perform main scanning, causes the print head 410 to eject ink to form dots on the paper PM, performs partial printing, and performs sub-scanning by the transport unit 440 (transporting the paper PM). and are executed a plurality of times to print an image on the paper PM.

FIG. 4A is an explanatory diagram of an example of the operation of the print execution unit 400. FIG. FIG. 4A shows the print image OI printed on the paper PM. In FIG. 4A, the +Dy direction is the conveying direction of the paper PM (that is, the sub-scanning direction). The print image OI includes a plurality of band images BI1 to BI4 arranged in the -Dy direction (more generally, the sub-scanning direction). Each of the band images BI1 to BI4 has a rectangular shape extending in the main scanning direction (here, the direction parallel to the Dx direction). Each band image BI1 to BI4 is normally printed by one partial printing. A print head 410 for printing a band image is shown on the right or left side of each band image BI1-BI4.

Directions D1 and D2 in the drawing indicate bi-directional main scanning directions. In this embodiment, the first direction D1 is the opposite direction to the Dx direction, and the second direction D2 is the same direction as the Dx direction. Hereinafter, the first direction D1 will also be referred to as the forward direction D1, and the second direction D2 will also be referred to as the backward direction D2. The printing direction for partial printing (that is, the moving direction of the print head 410) is either the forward direction D1 or the backward direction D2. Hereinafter, partial printing in the outward direction D1 is also referred to as forward printing. Partial printing in the backward direction D2 is also called backward printing. Also, one partial printing is also called "pass processing" or simply "pass".

A plurality of band images are sequentially printed one by one in the -Dy direction from the band image at the end of the print image OI on the +Dy direction side. As a result, the entire print image OI is printed. The printing of this embodiment is so-called one-pass printing, and the width of each band image in the transport direction is the same as the nozzle length D. FIG. In the example of FIG. 4A, the band images BI1 and BI3 are printed by forward printing, and the band image BI2 is printed by backward printing. Thus, in this embodiment, the printing direction of each band image is determined in advance so that backward printing and forward printing are alternately performed. Such a printing method is also called bi-directional printing. Bi-directional printing can reduce the time required for printing compared to uni-directional printing in which printing is performed only in main scanning in one direction.

Also, as will be described later, one band image may be printed by two partial printings. In the example of FIG. 4A, the fourth band image BI4 includes two partial images PId and PIu arranged in the -Dy direction (more generally, the sub-scanning direction). Each of the partial images PId and PIu has a rectangular shape extending in the main scanning direction. Each partial image PId, PIu is printed by one partial printing. In the example of FIG. 4A, the downstream partial image PId is printed by backward printing, and the upstream partial image PIu is printed by outward printing.

In this embodiment, the paper PM is not conveyed between the partial printing of the downstream partial image PId and the partial printing of the upstream partial image PIu. The position of the paper PM in the transport direction (+Dy direction) when the partial images PId and PIu are printed is the same as the position of the paper PM in the transport direction when the fourth band image BI4 is printed in one partial print. . Also, as will be described later, the printing direction of the partial image is determined depending on the situation. Further, in this embodiment, the width of the downstream partial image PId in the transport direction is the same as the width of the upstream partial image PIu in the transport direction. However, the width of the downstream partial image PId in the transport direction may be larger or smaller than the width of the upstream partial image PIu in the transport direction.

FIG. 4(B) is a schematic diagram showing the first order I1, which is the order of ink stacking in forward printing. FIG. 4(C) is a schematic diagram showing the second order I2, which is the order of overlapping of inks in backward printing. In this embodiment, the first order I1 is the order from the sheet PM to KYCM, and the second order I2 is the order from the sheet PM to MCYK. Thus, the second order I2 is opposite to the first order I1. If the order of ink layering is different between two printed colors, the two colors will appear different even if the type of ink layered and the amount per unit area of each of the various inks are the same. Sometimes.

Therefore, in this embodiment, in color conversion processing of print data generation processing, which will be described later, an outward color conversion profile LUT1 for forward printing and a backward color conversion profile LUT2 for backward printing are used. Color conversion processing is processing for converting input color values, which are color values indicated by data of an image to be printed, into ink color values, which are color values in an ink color space. The ink color space is a color space that corresponds to multiple types of ink colors that can be used for printing. An ink color value in the ink color space includes multiple component values corresponding to multiple ink colors. In this example, the input color values are RGB values and the ink color values are CMYK values. The color conversion profiles LUT1 and LUT2 are data indicating the correspondence between input color values and ink color values (for example, lookup data). In this embodiment, the color conversion profiles LUT1 and LUT2 are prepared in advance so that the difference in the appearance of colors printed based on the same input color values between forward printing and backward printing is small.

A-3. Handling printing:
FIG. 5 is a flowchart illustrating an example of print data generation processing. In this embodiment, the terminal device 100 (FIG. 1) and the control unit 299 of the MFP 200 are each capable of executing processing for generating print data for causing the print execution unit 400 to print an image. The print data generation process is started based on a print instruction from the user. In the following description, it is assumed that the terminal device 100 executes print data generation processing.

Any method may be used to input the print instruction. In this embodiment, the user inputs a print instruction by operating the operation unit 150 (FIG. 1). The print instruction includes information designating image data for printing. The image data designated by the print instruction is hereinafter also referred to as target image data. An image of target image data is also called a target image. Various data may be designated as the target image data. For example, image data stored in the storage device 115 (for example, the non-volatile storage device 130) or image data generated by an application running on the terminal device 100 may be specified.

In this embodiment, the target image data is bitmap data, and the pixel value of each pixel of the target image data is 256 gradations from 0 to 255 of R (red), G (green), and B (blue). It is assumed that it is represented by the tone value. If the specified image data format is different from the bitmap format (for example, EMF (Enhanced Meta File) format), the processor 110 converts (for example, rasterizes) the data format to generate bitmap data. Map data is used as target image data.

At S110, the processor 110 acquires target image data. The processor 110 identifies the page number Q (Q is an integer equal to or greater than 1) by analyzing the target image data. In S120, the processor 110 selects the first page among the unprocessed pages included in the Q page as the target page, which is the page to be processed. Hereinafter, the image of the target page is also referred to as the target page image.

In S130, the processor 110 selects an unprocessed band image on the +Dy side from among the plurality of band images included in the target page image as the target band image that is the band image to be processed. . As shown in FIG. 4A, the processor 110 places each of a plurality of band images on the target page image from the end of the target page image in the +Dy direction toward the -Dy direction according to the nozzle length D. Allocate an area. Then, the processor 110 selects the most downstream (+Dy side) band image among the unprocessed band images as the target band image.

In S140, the processor 110 acquires partial data representing the target band image from the target image data. At S150, resolution conversion processing of the partial data is executed. Resolution conversion processing is processing for converting the resolution of partial data into a predetermined print resolution for printing. Hereinafter, pixels of image data of print resolution are also called print pixels.

In S160, processor 110 executes color conversion processing of the partial data. Color conversion processing is processing for converting color values (RGB values in this embodiment) indicated by partial data into color values in the ink color space (CMYK values in this embodiment). In this embodiment, the processor 110 refers to the color conversion profile and executes color conversion processing. As described with reference to FIG. 4, the print direction of each band image is determined in advance. The processor 110 refers to the color conversion profile corresponding to the printing direction of the target band image, and converts the color value of each pixel indicated by the resolution-converted partial data into the color value of the ink color space. When the printing direction of the target band image is the forward direction D1, the forward color conversion profile LUT1 is referred to. When the printing direction is the backward direction D2, the backward color conversion profile LUT2 is referred to.

At S170, processor 110 performs halftone processing of the color-converted partial data. Halftone processing may be processing of various methods such as, for example, an error diffusion method and a method using a dither matrix. Halftone processing determines the state of dot formation for each color component and for each print pixel. The dot formation state is the state of dots to be formed by printing, and in this embodiment, it is either "with dots" or "without dots". Alternatively, the dot formation state may be three or more states including two or more dot states having different dot sizes (for example, "large dot", "medium dot", "small dot", and "no dot"). ”).

In S180, processor 110 generates band print data, which is print data for the target band image, using data representing the result of halftone processing. The print data is data in a data format that can be interpreted by the MFP 200 (in this embodiment, the control circuit 490 of the print execution unit 400). The band print data includes information specifying print pixels for forming ink dots, information indicating the printing direction of partial printing (that is, the direction in which the print head 410 moves in partial printing), and information about the page. I'm in. At S<b>190 , the processor 110 outputs the band print data to the MFP 200 . The processor 210 of the MFP 200 temporarily stores the received band print data in the storage device 215 (for example, the non-volatile storage device 230). Then, the processor 210 causes the print execution unit 400 to print a band image using the band print data (details will be described later).

In S200, the processor 110 determines whether or not all band images of the target page have been processed. If unprocessed band images remain (S200: No), the processor 110 proceeds to S130 and processes the unprocessed band images.

If all band images of the target page have been processed (S200: Yes), processor 110 determines in S210 whether all pages have been processed. If unprocessed pages remain (S210: No), the processor 110 proceeds to S120 and processes the unprocessed pages. If all pages have been processed (S210: Yes), processor 110 ends the process of FIG. As described above, the processor 110 generates a plurality of band print data one by one in order to be printed, and outputs them to the MFP 200 .

6 to 10 are flowcharts showing examples of print execution processing. FIG. 7 shows the processing following FIG. 6, and FIGS. 8 to 10 show the processing following FIG. The print execution process is a process of causing the print execution unit 400 (FIG. 1) to print an image using print data. The print execution process is executed by the control unit 299 of the MFP 200 (FIG. 1). The processor 210 of the control unit 299 starts print execution processing in response to acquiring the band print data.

At S310, the processor 210 (FIG. 1) acquires band print data. In this embodiment, the processor 210 acquires the band print data to be printed first from the band print data already stored in the storage device 215 . Hereinafter, the acquired band print data to be processed is also referred to as target band data. An image of target band data is also called a target band image.

In S320, the processor 210 causes the print executing unit 400 to transport the paper PM so that the position of the paper PM in the transport direction is the position where the target band image should be printed. When the target band image is the first band image of a new page, processor 210 controls print execution unit 400 to supply new paper PM to transport unit 440 .

In S323, the processor 210 refers to the target band data and identifies the target print direction, which is the print direction of the target band data. At S325, the processor 210 determines whether the position of the head 410 is suitable for the target print direction. After partial printing is completed, the head 410 (FIG. 2) is positioned on the forward direction D1 side of the paper PM or on the backward direction D2 side of the paper PM. The head 410 located on the forward direction D1 side of the paper PM can quickly start partial printing in the reverse direction D2. The head 410 located on the side of the paper PM in the backward direction D2 can quickly start partial printing in the opposite forward direction D1. Thus, the position on the side opposite to the target printing direction is the position suitable for the target printing direction.

If the position of the print head 410 is not suitable for the target print direction (S325: No), the processor 210 causes the print execution unit 400 to move the print head 410 to the opposite side in S328, and proceeds to S330. Through S328, the head 410 is moved to a position suitable for the target printing direction. If the position of the print head 410 is suitable for the target print direction (S325: Yes), the processor 210 skips S328 and proceeds to S330.

At S330, the processor 210 acquires the number of times the ink cartridge has been replaced. When the ink cartridge is to be replaced, the ink cartridge is removed from the cartridge mounting portion 451 (FIG. 2), and then a new ink cartridge is mounted to the cartridge mounting portion 451. FIG. Accordingly, the signals from the cartridge sensors 454K, 454Y, 454C, and 454M change from ON signals to OFF signals, and then change from OFF signals to ON signals. Processor 210 monitors the signals from cartridge sensors 454K, 454Y, 454C, and 454M and determines that the cartridge has been replaced when it detects changes in the signals as described above. The replacement frequency table 310 of the nonvolatile storage device 230 (FIG. 1) stores the replacement frequency of each ink cartridge. When the MFP 200 is shipped, the number of replacement times for each ink in the replacement number table 310 is initialized to zero. The processor 210 adds 1 to the corresponding ink replacement count in the replacement count table 310 in response to detection of replacement of the cartridge. The processor 210 identifies the number of replacement times for each ink by referring to the replacement number table 310 . An ink cartridge is usually replaced when the amount of ink remaining in the ink cartridge is below a reference value. Therefore, the greater the number of exchanges, the greater the cumulative amount of ink used. The number of exchanges is an index value of the cumulative amount of ink used.

At S340, processor 210 determines the temperature of print head 410 using the signal from temperature sensor 470 (FIG. 2).

In S350, processor 210 calculates the dot formation rate of each ink used for printing using the target band data. The dot formation rate is the ratio of the number of dot pixels to the total number of print pixels of the target band image. A dot pixel is a pixel having a value indicating dot formation in the target band data. The higher the dot formation rate, the greater the amount of ink used in one partial print. Hereinafter, the amount of ink used for one partial print will also be referred to as a "pass ink amount". The dot formation rate is an index value of the amount of pass ink used.

Note that when the dot formation state is selected from three or more states including two or more states with dots having different dot sizes, the dot formation rate is the ratio of the number of dot pixels weighted by the dot size. may be used. For example, a "large dot" dot pixel is counted as 1 pixel, a "medium dot" dot pixel is counted as 0.5 pixel, and a "small dot" dot pixel is counted as 0.25 pixel. you can

At S360, the processor 210 determines whether the supply conditions are met for at least one ink used to print the target band image. The supply condition is a condition indicating that the supply of ink from the ink supply unit 450 to the print head 410 may be delayed in partial printing. In this embodiment, the supply condition is "the dot formation rate is greater than the determination threshold". The determination threshold is defined by the threshold table 300 (FIG. 1).

FIG. 11 is an explanatory diagram showing an example of the threshold table 300. As shown in FIG. The threshold table 300 defines the correspondence relationship between the combination of the head temperature and the cumulative amount of ink used and the determination threshold. In the example of FIG. 11, the head temperature is pre-divided into three ranges of "low", "medium" and "high", and the cumulative ink usage is divided into three ranges of "small", "medium" and "large". Pre-divided into ranges. In this embodiment, the number of times the ink cartridge has been replaced is used as the index value for the cumulative amount of ink used. As shown in the figure, when the cumulative ink usage is constant, the lower the head temperature, the smaller the determination threshold. The reason for this is that the lower the head temperature, the easier it is for the ink supply to be delayed. Further, when the head temperature is constant, the larger the cumulative amount of ink used, the smaller the determination threshold. The reason for this is that the greater the cumulative amount of ink used, the easier it is for ink supply to be delayed.

The processor 210 refers to the threshold table 300 to identify the determination threshold associated with the combination of head temperature and cumulative ink usage. In the example of FIG. 11, for example, when the head temperature is within the predetermined "middle" range and the cumulative ink usage is within the predetermined "large" range, the determination The threshold is "75%".

The supply condition is determined for each ink used for printing based on the target band data. Hereinafter, the ink used for printing based on target band data will also be referred to as band-using ink. For example, if printing based on the target band data is printing using each of CMYK inks, the processor 210 specifies a determination threshold for each of the CMYK inks and determines whether the supply conditions are met. . If printing based on the target band data is printing using black K ink only, processor 210 specifies a decision threshold for black K ink and determines whether the supply conditions are met. Note that the correspondence relationship between the combination of the head temperature and the cumulative amount of ink used and the determination threshold value may be common to a plurality of types of ink, or alternatively may be determined in advance for each ink.

If the supply conditions are not satisfied for all the band-use inks (Fig. 6: S360: No), the possibility of delay in ink supply is low. In this case, in S900, the processor 210 causes the print executing unit 400 to print the target band image in one partial print. For example, processor 210 supplies target band data to print execution unit 400 . The control circuit 490 of the print execution unit 400 prints the target band image in one partial print by controlling each element of the print execution unit 400 according to the received target band data. The printing direction of partial printing is set to the direction indicated by the target band data. After partial printing, the processor 210 transitions to S910.

For at least one band-based ink, if the supply condition is met (S360: Yes), the supply of ink may be delayed. In this case, at S370 (FIG. 7), processor 210 determines whether printing based on the target band data is monochrome printing. Monochromatic printing is printing that uses only one type of ink (ie, only one type of ink is used in the band).

If only one type of ink is used for the band (S370: Yes), in S510 of FIG. 8, the processor 210 uses the target band data to generate downstream partial print data and upstream partial print data. . The downstream partial print data is print data representing a partial image on the downstream side, such as the downstream partial image PId in FIG. 4A. The upstream partial print data is print data representing an upstream partial image, like the upstream partial image PIu.

In this embodiment, the print data includes dot data for each print pixel on which an ink dot is to be formed. The dot data is data that indicates the correspondence between the positions of print pixels where ink dots are to be formed, the type of ink, and the size of the dots. The processor 210 can generate downstream print data and upstream print data by dividing the target band data into a portion representing the downstream partial image and a portion representing the upstream partial image. In the present embodiment, the mask data 321 (FIG. 1) contains in advance each of a plurality of pixels included in one band image and either the identifier of the downstream partial image or the identifier of the upstream partial image. are associated. The processor 210 can appropriately divide the target band data by referring to the mask data 321 . Also in other steps described later, the processor 210 generates downstream partial print data and upstream partial print data from the target band data by referring to the mask data 321 .

Note that when the dot formation state is either "dots present" or "dots absent", the information indicating the dot size may be omitted from the dot data. Further, the downstream portion print data and the upstream portion print data include information indicating the print direction. In this embodiment, at S510, the processor 210 sets both the printing direction of the downstream partial print data and the printing direction of the upstream partial print data to the same direction as the target printing direction. However, when only one type of ink is used for the band, there is no difference in the appearance of the printed colors due to the difference in the order of overlapping the inks. Therefore, the printing direction of at least one of the downstream partial print data and the upstream partial print data may be set to the direction opposite to the target printing direction.

In S515, the processor 210 supplies the downstream partial print data to the print execution unit 400 to cause the print execution unit 400 to print the downstream partial image in one partial print. As a result, ink dots are formed in the print pixels of the downstream partial image. Hereinafter, the downstream partial image of the target band image will also be referred to as the first portion.

In S520, the processor 210 supplies the upstream partial print data to the print execution unit 400 to cause the print execution unit 400 to print the upstream partial image in one partial print. As a result, ink dots are formed in the print pixels of the upstream partial image. Hereinafter, the upstream partial image of the target band image will also be referred to as the second portion. Note that if the position of the print head 410 after S515 is not suitable for the print direction of the partial print of S520, the processor 210 instructs the print execution unit 400 to move the print head 410 to the opposite side before partial printing. Let

Through S515 and S520, the entire target band image is printed. The processor 210 then proceeds to S910 (FIG. 6).

If the total number of band-use inks is 2 or more (FIG. 7: S370: No), processor 210 determines in S380 whether the band-use inks include black K ink.

If the band-use ink includes black K ink (S380: Yes), in S390 the processor 210 determines that the target ink, which is the ink determined in S360 (FIG. 6) to be delayed in supply, is the first end nozzle row. It is determined whether or not it is only the first end ink, which is the ink of the The first end nozzle row is the end nozzle row on the first direction D1 side among the plurality of nozzle rows NC, NM, NY, and NK of the print head 410 (FIG. 4A). In this embodiment, the first end nozzle row is the nozzle row NK for black K ink, and the first end ink is black K ink (hereafter, black K ink is also referred to as first end ink K). call).

If the target ink is only the first end ink K (S390: Yes), in S540 of FIG. K downstream part print data and K upstream part print data are generated by dividing into a part showing an upstream part image. CMY data in the target band data is not divided.

At S545, the processor 210 identifies the target overlay order, which is the overlay order of the inks based on the target print direction. The relationship between the target printing direction and the target stacking order is determined in advance, as described with reference to FIGS. 4(B) and 4(C).

In S550, the processor 210 determines whether or not the stacking order of the first end ink K in the target stacking order is the last (here, No. 4). In this embodiment, when the target stacking order is the second order I2 (FIG. 4C) (that is, when the target printing direction is the second direction D2), the determination result of S550 is Yes.

If the determination result in S550 is YES, in S555 the processor 210 generates print data including CMY print data of the target band data and K downstream part print data (first multicolor print data). (also called data). The processor 210 sets the print direction of the first multicolor print data to the target print direction (here, the second direction D2). Processor 210 supplies the first multicolor print data to print execution unit 400 . The print execution unit 400 executes one partial print according to the first multicolor print data. All dot pixels included in the target band image are printed for each of the CMY inks. As for the K ink, dot pixels included in the downstream partial image are printed.

The block of S555 in FIG. 8 shows an example of the state of ink dots in two print pixels PX1 and PX2 in the target band image. These pixels PX1 and PX2 are pixels for which all CMYK inks should be finally discharged. The first pixel PX1 is a pixel included in the downstream partial image (hereinafter also referred to as downstream reference pixel PX1). All CMYK inks are ejected to the downstream reference pixel PX1. The second pixel PX2 is a pixel included in the upstream partial image (hereinafter also referred to as upstream reference pixel PX2). The first end ink K is not ejected to the upstream reference pixel PX2, but the CMY inks are ejected. In S555, partial printing in the target printing direction (here, backward direction D2) is performed, so the ink superposition order in each of the pixels PX1 and PX2 matches the target superposition order.

At S560, the processor 210 sets the print direction of the upstream partial print data of K to the direction opposite to the target print direction. The processor 210 then supplies the K upstream portion print data to the print execution unit 400 . The print execution unit 400 executes one partial print according to the K upstream partial print data. As a result, with respect to the first end ink K, dot pixels included in the upstream partial image are printed. As indicated by the two reference pixels PX1 and PX2 in the block of S560, the first end ink K is ejected to the upstream reference pixel PX2 in S560. As a result, all the CMYK inks are ejected in both the reference pixels PX1 and PX2, and the order of superimposition of the inks is the same as that of the target superposition.

Through S555 and S560, the entire target band image is printed. The processor 210 then proceeds to S910 (FIG. 6).

If the determination result of S550 is No, the stacking order of the first end ink K in the target stacking order is first. In this case, at S580, processor 210 causes print execution unit 400 to move print head 410 to the opposite side. In S585, the processor 210 sets the print direction of the downstream partial print data of K to the direction opposite to the target print direction (here, the second direction D2). The processor 210 then supplies the K downstream portion print data to the print execution unit 400 . The print execution unit 400 executes one partial print according to the K downstream partial print data. As a result, with respect to the first end ink K, dot pixels included in the downstream partial image are printed. The block of S585 shows an example of the state of the ink dots in the two reference pixels PX1 and PX2 described above. In S585, the first end ink K is ejected onto the downstream reference pixel PX1. The stacking order (No. 1) of the first end ink K is the same as the stacking order of the first end ink K in the target stacking order (here, KYCM).

In S590, the processor 210 generates print data including the CMY band data of the target band data and the upstream partial print data of K (also referred to as second multicolor print data). The processor 210 sets the print direction of the second multicolor print data to the target print direction (here, the first direction D1). Processor 210 supplies the generated second multi-color print data to print execution unit 400 . The print execution unit 400 executes one partial print according to the second multicolor print data. All dot pixels included in the target band image are printed for each of the CMY inks. As for the first end ink K, dot pixels included in the upstream partial image are printed. As described above, all CMYK inks are ejected from both the reference pixels PX1 and PX2. Also, in S590, partial printing in the target printing direction (here, the first direction D1) is performed, so the order of ink overlapping in each of the reference pixels PX1 and PX2 is the same as the target overlapping order.

Through S585 and S590, the entire target band image is printed. The processor 210 then proceeds to S910 (FIG. 6).

In S390 of FIG. 7, if the target ink includes ink other than the first end ink K, the determination result of S390 is No. In this case, in S400, the processor 210 determines whether or not the target ink is only the second end ink, which is the ink of the second end nozzle row. The second end nozzle row is the end nozzle row on the second direction D2 side among the plurality of nozzle rows NC, NM, NY, and NK of the print head 410 (FIG. 4A). In this embodiment, the second end nozzle row is the magenta M ink nozzle row NM, and the second end ink is the magenta M ink (hereinafter, the magenta M ink is also referred to as the second end ink M). call).

If the target ink is only the second end ink M (S400: Yes), in S640 of FIG. M downstream portion print data and M upstream portion print data are generated by dividing into portions showing upstream portion images. The KCY data in the target band data is not divided.

S645 is the same as S545 in FIG. In S650, the processor 210 determines whether or not the stacking order of the second end ink M is first in the target stacking order. If the target stacking order is the second order I2 (FIG. 4C) (that is, if the target printing direction is the second direction D2), the determination result of S650 is Yes.

If the determination result of S650 is No, the stacking order of the second end ink M in the target stacking order is the last (here, No. 4). In this case, at S655, the processor 210 generates print data including the CMY print data of the target band data and the M downstream part print data (also called third multicolor print data). The processor 210 sets the print direction of the third multicolor print data to the target print direction (here, the first direction D1). Processor 210 supplies the third multi-color print data to print execution unit 400 . The print execution unit 400 executes one partial print according to the third multicolor print data. For each KCY ink, all dot pixels included in the target band image are printed. As for the second end ink M, dot pixels included in the downstream partial image are printed.

As indicated by the two reference pixels PX1 and PX2 in the block of S655, all CMYK inks are ejected to the downstream reference pixel PX1 in S655. The ink of KCY is ejected to the upstream reference pixel PX2 without the second end ink M being ejected. In S655, partial printing in the target printing direction (here, forward direction D1) is performed, so the ink superimposition order in each of the reference pixels PX1 and PX2 matches the target superimposition order.

At S660, the processor 210 sets the print direction of the upstream partial print data of M to the direction opposite to the target print direction. The processor 210 then supplies the M upstream partial print data to the print execution unit 400 . The print execution unit 400 executes one partial print according to the M upstream partial print data. As a result, for the second end ink M, dot pixels included in the upstream partial image are printed. As indicated by the two reference pixels PX1 and PX2 in the block of S660, the second end ink M is ejected to the upstream reference pixel PX2 in S660. As a result, all the CMYK inks are ejected in both the reference pixels PX1 and PX2, and the order of superimposition of the inks is the same as that of the target superposition.

Through S655 and S660, the entire target band image is printed. The processor 210 then proceeds to S910 (FIG. 6).

If the determination result of S650 is Yes, the stacking order of the second end ink M in the target stacking order is first. In this case, at S680, processor 210 causes print execution unit 400 to move print head 410 to the opposite side. In S685, the processor 210 sets the print direction of the downstream partial print data of M to the direction opposite to the target print direction (here, the first direction D1). The processor 210 then supplies the M downstream portion print data to the print execution unit 400 . The print execution unit 400 executes one partial print according to the M downstream partial print data. As a result, dot pixels included in the downstream partial image are printed with respect to the M ink. As indicated by the two reference pixels PX1 and PX2 in the block of S685, in S685, the second end ink M is ejected to the downstream reference pixel PX1. The stacking order (first) of the second end ink M is the same as the stacking order of the second end ink M in the target stacking order (here, MCYK).

In S690, the processor 210 generates print data including the KCY band data of the target band data and the M upstream partial print data (also called fourth multicolor print data). The processor 210 sets the printing direction of the fourth multicolor print data to the target printing direction (here, the second direction D2). Processor 210 supplies the generated fourth multi-color print data to print execution unit 400 . The print execution unit 400 executes one partial print according to the fourth multicolor print data. For each KCY ink, all dot pixels included in the target band image are printed. As for the second end ink M, dot pixels included in the upstream partial image are printed. As described above, all CMYK inks are ejected from both the reference pixels PX1 and PX2, as indicated by the two reference pixels PX1 and PX2 in the block of S690. Also, in S690, partial printing in the target printing direction (here, the second direction D2) is performed, so the order of ink superimposition in each of the reference pixels PX1 and PX2 is the same as the target superimposition order.

Through S685 and S690, the entire target band image is printed. The processor 210 then proceeds to S910 (FIG. 6).

In S400 of FIG. 7, when the target ink includes ink other than the second end ink M, the determination result of S400 is No. In this case, the determination results of both S390 and S400 are No. Therefore, the target inks include inks other than the first end ink K and the second end ink M (in this embodiment, at least one of cyan C and yellow Y). In this case, in S710 of FIG. 10, the processor 210 divides the target band data into a portion showing the downstream partial image and a portion showing the upstream partial image, thereby generating the downstream partial print data and the upstream partial print data. do. At S710, the data for all inks are split. Also, the processor 210 sets the print orientation of each of the downstream print data and the upstream print data to the target print orientation.

At S<b>715 , the processor 210 supplies the downstream portion print data to the print execution unit 400 . The print execution unit 400 executes one partial print according to the downstream partial print data. This completes printing of all print pixels included in the downstream partial image. At S720, processor 210 causes print execution unit 400 to move print head 410 to the opposite side.

At S<b>725 , the processor 210 supplies the upstream partial print data to the print execution unit 400 . The print execution unit 400 executes one partial print according to the upstream partial print data. This completes the printing of all print pixels included in the upstream partial image. The processor 210 then proceeds to S910 (FIG. 6).

In S380 of FIG. 7, if the band-use ink does not include black K ink (S380: No), in S410, the processor 210 detects all chromatic inks (three CMY in this embodiment). ink). If at least one chromatic ink is a non-target ink (S410: No), in S750 of FIG. By dividing into a portion representing an image, downstream portion print data for the target ink and upstream portion print data for the target ink are generated. Ink data other than the target ink in the target band data is not divided.

In S755, the processor 210 sets the print direction of the downstream portion print data for the target ink to the target print direction. The processor 210 then supplies the downstream portion print data for the target ink to the print execution unit 400 . The print execution unit 400 executes one partial print according to the downstream partial print data of the target ink. As a result, dot pixels included in the downstream partial image are printed for the target ink.

At S760, the processor 210 generates print data including non-target ink band data of the target band data and upstream portion print data for the target ink (also referred to as fifth multi-color print data). The processor 210 sets the print direction of the fifth multicolor print data to the direction opposite to the target print direction. Processor 210 supplies the generated fifth multi-color print data to print execution unit 400 . The print execution unit 400 executes one partial print according to the fifth multicolor print data. For non-target ink, all dot pixels included in the target band image are printed. For the target ink, dot pixels included in the upstream partial image are printed.

Through S755 and S760, the entire target band image is printed. The processor 210 then proceeds to S910 (FIG. 6). Note that in the partial printing of S755 and S760, the ink overlapping order may differ from the target overlapping order. In this embodiment, when an image is printed without using black K ink (i.e., when an image is printed using only CMY inks), the printed colors caused by the difference in the ink superimposition order It is assumed that the difference in appearance is small. In the target band image printed in S755 and S760, even if the ink superposition order is different from the target superimposition order, the difference in appearance of printed colors is suppressed.

In S410 of FIG. 7, if the target inks include all chromatic inks (three inks of CMY in this embodiment) (S410: Yes), in S780 of FIG. By dividing the data into a portion representing the downstream portion image and a portion representing the upstream portion image, downstream portion print data and upstream portion print data are generated. In S780, since the target band data does not include black K print data, the downstream print data and the upstream print data are print data for chromatic ink YCM.

At S785, the processor 210 sets the print direction of the downstream portion print data to the target print direction. Processor 210 then supplies the downstream portion print data to print execution unit 400 . The print execution unit 400 executes one partial print according to the downstream partial print data. As a result, dot pixels included in the downstream partial image are printed with the chromatic ink YCM.

At S790, the processor 210 sets the print direction of the upstream portion print data to the direction opposite to the target print direction. The processor 210 then supplies the upstream partial print data to the print execution unit 400 . The print execution unit 400 executes one partial print according to the upstream partial print data. As a result, dot pixels included in the upstream partial image are printed with the chromatic ink YCM.

Through S785 and S790, the entire target band image is printed. The processor 210 then proceeds to S910 (FIG. 6). Note that in the partial printing of S785 and S790, the ink overlapping order may differ from the target overlapping order. In this embodiment, similar to the printing in S755 and S760, the difference in the appearance of printed colors is suppressed.

At S910 (FIG. 6), the processor 210 determines whether or not all band print data have been processed. If unprocessed band print data remains (S910: No), the processor 210 proceeds to S310 and processes the unprocessed band print data. If all band print data have been processed (S910: Yes), the processor 210 ends the print execution process of FIGS.

As described above, in this embodiment, the print execution unit 400 (FIGS. 1 and 2) includes the print head 410, the ink supply unit 450 that supplies four types of ink to the print head 410, and the main scanning unit 430. , and a carriage 440 . The print head 410 (FIG. 3) has four nozzle rows NK, NY, NC, and NM for ejecting four types of KYCM ink. These nozzle rows NK, NY, NC, and NM are arranged side by side in the main scanning direction. The main scanning unit 430 (FIG. 2) performs main scanning for moving the print head 410 along the main scanning direction with respect to the paper PM. The transport unit 440 performs sub-scanning to move the paper PM along the sub-scanning direction (also referred to as the transport direction) that intersects the main scanning direction with respect to the print head 410 (hereinafter, the transport unit 440 is referred to as the sub-scanning unit). 440). As described with reference to FIG. 4A and the like, the control unit 299 of the MFP 200 causes the main scanning unit 430 to perform main scanning and causes the print head 410 to eject ink for partial printing and the sub scanning unit 440 to perform sub printing. Scanning is performed a plurality of times to cause the print execution unit 400 to print an image.

At S360 (FIG. 6), the processor 210 determines whether a supply condition is met indicating that the supply of at least one type of ink from the ink supply 450 to the print head 410 may be delayed in the partial print. This determination is made for each of the plurality of band images included in the image to be printed and arranged in the sub-scanning direction. If the supply condition is not satisfied (S360: No), in S900 processor 210 causes print execution unit 400 to print a band image by causing print execution unit 400 to execute one partial print.

If the supply condition is satisfied (FIG. 6: S360: Yes), the processor 210 causes the print executing unit 400 to execute the multiple-part printing process including the partial printing twice, as described with reference to FIGS. causes the print execution unit 400 to print the band image. Therefore, the amount of ink used for one partial printing is reduced, so delays in ink supply can be suppressed.

Here, the printing of the band image by the two partial printings of S555-S560 in FIG. 8 is executed in the following first case. In the first case, the supply condition is satisfied (Fig. 6: S360: Yes), and the target ink, which is determined to be delayed in supply, is the first end ink K (Fig. 7: S390). : Yes) is satisfied (specifically, FIG. 6: S360: Yes, FIG. 7: S370: No, S380: Yes, S390: Yes, FIG. 8: S550: Yes) . Here, the first end ink K is the ink of the first end nozzle row NK located at one end in the main scanning direction among the four nozzle rows NK, NY, NC, and NM. Then, in S555 and S560, a first multiple partial printing process including two partial printings using the first end ink K as the first target ink is performed. Specifically, in the first partial printing in S555, the print head 410 is moved in the direction in which the stacking order of the first target ink (here, the first end ink K) is the last (here, No. 4). Four types of ink are ejected to the print head 410 while causing the main scanning unit 430 to perform the main scanning for moving with respect to. In the second partial printing in S560, only the first ink of interest is ejected to the print head 410 without ejecting the three types of ink YCM other than the first ink of interest (here, the first end ink K) to the print head 410. Let it spit out.

In this way, in the first case, since the ejection of the first end ink K for printing the band image is divided into two partial printings (S555, S560), the supply of the first end ink K is delay can be suppressed. Also, when one band image is printed by two partial printings, it is possible to suppress the occurrence of a plurality of parts in one band image in which the stacking order of the four types of ink KYCM is different from each other. Therefore, it is possible to suppress the misalignment of printed colors.

Also, the printing of band images by two partial printings from S685 to S690 in FIG. 9 is executed in the following second case. In the second case, specific conditions including that the supply condition is satisfied (Fig. 6: S360: Yes) and that the target ink is the second end ink M (Fig. 7: S400: Yes) This is the case where the conditions are satisfied (specifically, FIG. 6: S360: Yes, FIG. 7: S370: No, S380: Yes, S390: No, S400: Yes, FIG. 9: S650: Yes). Here, the second end ink M is the ink of the second end nozzle row NM located at the end on the other side in the main scanning direction among the four nozzle rows NK, NY, NC, and NM. Then, in S685 and S690, a second multiple partial printing process including two partial printings using the second end ink M as the second target ink is performed. Specifically, in the first partial printing in S685, only the second target ink is ejected without causing the print head 410 to eject the three types of ink KYC other than the second target ink (here, the second end ink M). is ejected to the print head 410 . In the second partial printing in S690, the main scanning unit performs the main scanning for moving the print head 410 with respect to the paper PM in the direction in which the second target ink (here, the second end ink M) is stacked first. 430 to eject four types of ink to the print head 410 .

In this way, in the second case, since the ejection of the second end ink M for printing the band image is dispersed in two partial printings (S685, S690), the second end ink M is supplied. delay can be suppressed. Also, when one band image is printed by two partial printings, it is possible to suppress the occurrence of a plurality of parts in one band image in which the stacking order of the four types of ink KYCM is different from each other. Therefore, it is possible to suppress the misalignment of printed colors.

Also, as described in S555 (FIG. 8) and S685 (FIG. 9), the main scanning direction (here, the first direction D1) in the first partial printing (FIG. 9: S685) in the second case is the direction opposite to the main scanning direction (here, the second direction D2) in the first partial printing (FIG. 8: S555) in the first case. Therefore, when the same target band image is printed, the stacking order of the four types of ink between the case where the target ink is the first end ink K and the case where the target ink is the second end ink M can suppress the occurrence of a plurality of portions different from each other. As a result, it is possible to suppress the deviation of printed colors.

In addition, in S545 of FIG. 8 and S645 of FIG. 9, the processor 210 identifies the target stacking order, which is the stacking order of the inks based on the target printing direction. The target stacking order is the stacking order of the four types of ink in one partial print performed in S900 if the supply condition is not satisfied (FIG. 6: S360: No).

Further, in S555 and S560 of FIG. 8, as described above, the first multiple partial printing process including two partial printings using the first end ink K as the first target ink is performed. The conditions for performing the first multiple-portion printing process (including S555 and S560) are that the supply conditions are satisfied (FIG. 6: S360: Yes) and that the target ink is the first end ink K. (Fig. 7: S390: Yes), the order of the first end ink K in the target stacking order is last (here, No. 4), and (Fig. 8: S550: Yes). (Specifically, FIG. 6: S360: Yes, FIG. 7: S370: No, S380: Yes, S390: Yes, FIG. 8: S550: Yes).

Further, the processes of S585 and S590 in FIG. 8 are obtained by changing the second ink of interest in the second multiple-portion printing process described in S685 and S690 of FIG. 9 from the second end ink M to the first end ink K. Same as processing. The conditions for performing the second multiple-portion printing process (including S585 and S590) are that the supply conditions are satisfied (FIG. 6: S360: Yes) and that the target ink is the first end ink K. (Fig. 7: S390: Yes), and the order of the first end ink K in the target stacking order is the first (Fig. 8: S550: No). (Specifically, FIG. 6: S360: Yes, FIG. 7: S370: No, S380: Yes, S390: Yes, FIG. 8: S550: No).

In addition, in S685 and S690 of FIG. 9, as described above, the second multiple partial printing process including two partial printings using the second end ink M as the second target ink is performed. The conditions for performing the second multiple-portion printing process (including S685 and S690) are that the supply conditions are satisfied (FIG. 6: S360: Yes) and that the target ink is the second end ink M. (Fig. 7: S400: Yes), the order of the second end ink M in the target stacking order is first (Fig. 9: S650: Yes), and specific conditions are satisfied (specifically, 6: S360: Yes, FIG. 7: S370: No, S380: Yes, S390: No, S400: Yes, FIG. 9: S650: Yes).

Further, the processes of S655 and S660 in FIG. 9 are obtained by changing the first ink of interest in the first multiple-portion printing process described in S555 and S560 of FIG. 8 from the first end ink K to the second end ink M. Same as processing. The conditions for performing the first multiple-portion printing process (including S655 and S660) are that the supply condition is satisfied (FIG. 6: S360: Yes) and that the target ink is the second end ink M. (FIG. 7: S400: Yes), and the order of the second end ink M in the target stacking order is the last (here, No. 4) (FIG. 9: S650: No). (Specifically, FIG. 6: S360: Yes, FIG. 7: S370: No, S380: Yes, S390: No, S400: Yes, FIG. 9: S650: No).

As described above, the configuration of the multiple-portion printing process (here, two-part printing) is controlled using the target ink and the order of overlapping of the inks. Yes), it is possible to prevent the ink stacking order from being different from the target stacking order.

Further, the conditions for performing the processing of S715-S725 in FIG. 10 are that the supply condition is satisfied (FIG. 6: S360: Yes), and that the target ink is four nozzle rows NK, NY, NC, NM ( 3) includes the inks Y and C of the nozzle rows NY and NC positioned inside the nozzle rows NK and NM positioned at both ends in the main scanning direction (FIG. 7: S390: No, S400: No) (specifically, FIG. 6: S360: Yes, FIG. 7: S370: No, S380: Yes, S390: No, S400: No). In S715-S725, two partial printings in which the main scanning direction is the same and four types of ink are ejected from the print head 410 are performed. In this way, since the ejection of the target ink is distributed over two partial printings, delays in ink supply can be suppressed. Furthermore, since partial printing is performed twice in the same main scanning direction, it is possible to suppress the occurrence of a plurality of portions in which the four types of ink overlap in different order within one band image. Therefore, it is possible to suppress the misalignment of printed colors.

8 to 10, when the supply condition is satisfied (FIG. 6: S360: Yes), the processor 210 sends the print execution unit 400 twice to print one band image. to perform partial printing. As described with reference to FIG. 4A, two partial printings print the downstream partial image PId and the upstream partial image PIu included in one band image. In this embodiment, the downstream partial image PId and the upstream partial image PIu are composed of a plurality of different pixels. That is, in the second partial printing, the target ink is not ejected to the pixel positions where the target ink was ejected in the first partial printing, and the target ink is not ejected in the pixel positions where the target ink was not ejected in the first partial printing. is discharged. Therefore, it is possible to appropriately suppress the delay in the supply of the target ink while appropriately printing the band image by performing the partial printing twice.

Also, as described in S510 (FIG. 8) and the like, the processor 210 refers to the mask data 321 (FIG. 1) to generate downstream partial print data and upstream partial print data from the target band data. That is, the pixel positions where ink should be ejected in each of the two partial printings are specified by referring to the mask data 321 . The mask data 321 is data indicating pixel positions where ink can be ejected in each of the two partial printings. Therefore, the processor 210 can appropriately specify the pixel positions where ink should be ejected in each of the two partial prints.

Further, as described with reference to FIG. 3 and the like, the first end ink K of the first end nozzle row NK located at one end in the main scanning direction among the four nozzle rows NK, NY, NC, and NM is Black K ink. Therefore, in this embodiment, when the black K ink is used for printing, it is possible to suppress the delay in the supply of the black K ink. Also, when one band image is printed by two partial printings, it is possible to prevent occurrence of a plurality of parts in one band image in which the order of stacking four types of ink including black K ink is different from each other. can be suppressed.

B. Second embodiment:
FIG. 12 is a flow chart showing part of the second embodiment of the print execution process. The process of FIG. 12 shows the process when the judgment result of S380 of FIG. 7 is No. In the second embodiment, the processes of S410 in FIG. 7, S750-S760 and S780-S790 in FIG. 10 are replaced with the processes in FIG. Other parts of the print execution process are the same as the corresponding parts of the first embodiment. The processing of FIG. 12 will be described below, and the description of other steps will be omitted.

At S810, the processor 210 selects candidate inks that are unprocessed inks from the inks available for printing. At S820, processor 210 determines whether the candidate ink is a target ink that has been determined to be delayed in delivery.

If the candidate ink is the target ink (S820: Yes), in S830 the processor 210 divides the print data of the candidate ink in the target band data into a portion representing the downstream partial image and a portion representing the upstream partial image. By doing so, downstream partial print data for the candidate ink and upstream partial print data for the candidate ink are generated. Then, the processor 210 incorporates the downstream partial print data into the first partial print data, which is the print data for the first partial printing, and incorporates the upstream partial print data into the second partial print data, which is the print data for the second partial printing. Include in partial print data. The processor 210 then moves to S850.

If the candidate ink is not the target ink (S820: No), at S840 processor 210 incorporates the print data for the candidate ink of the target band data into the second partial print data. The processor 210 then moves to S850.

At S850, processor 210 determines whether or not all inks have been processed. If unprocessed ink remains (S850: No), the processor 210 proceeds to S810 to process the unprocessed ink. As described above, the first partial print data and the second partial print data are generated. The first partial print data is print data of the target ink for a plurality of pixels included in the downstream partial image. The first partial print data does not include print data for non-targeted inks. The second partial print data includes target ink print data for a plurality of pixels included in the upstream partial image and non-target ink print data for a plurality of pixels included in the target band image.

If all inks have been processed (S850: Yes), in S860 the processor 210 sets the print direction of the first partial print data to the target print direction. Processor 210 then supplies the first partial print data to print execution unit 400 . The print execution unit 400 executes one partial print according to the first partial print data. As a result, dot pixels included in the downstream partial image are printed for the target ink.

At S870, the processor 210 sets the print direction of the second partial print data to the direction opposite to the target print direction. Processor 210 supplies the second partial print data to print execution unit 400 . The print executing unit 400 executes one partial print according to the second partial print data. For non-target ink, all dot pixels included in the target band image are printed. For the target ink, dot pixels included in the upstream partial image are printed.

Through S860 and S870, the entire target band image is printed. The processor 210 then proceeds to S910 (FIG. 6). The printing of the target band image by S860-S870 is the same as the printing by S755-S760 in FIG. 10 and the printing by S785-S790. As described above, various procedures can be adopted as the procedure for printing the target band image without using the black K ink. In general, various procedures can be adopted as procedures for obtaining the same print result of the target band image.

C. Third embodiment:
FIGS. 13A and 13B are schematic diagrams illustrating another example of mask data that can be used in place of mask data 321 (FIG. 1). FIG. 13A shows a first mask pattern 321a1 and a second mask pattern 321a2 of mask data 321a. A hatched portion in the band image BI indicates an arrangement pattern (also called a mask pattern) of a plurality of print pixels to be printed. The first mask pattern 321a1 indicates the mask pattern for the first partial printing, and the second mask pattern 321a2 indicates the mask pattern for the second partial printing. As shown, the second mask pattern 321a2 indicates a plurality of predetermined-shaped (here, rectangular) regions, and the first mask pattern 321a1 indicates the remaining region. The first mask pattern 321a1 may be the mask pattern for the second partial printing, and the second mask pattern 321a2 may be the mask pattern for the first partial printing.

FIG. 13B shows a first mask pattern 321b1 and a second mask pattern 321b2 of mask data 321b. As illustrated, the first mask pattern 321b1 and the second mask pattern 321b2 show a checkered pattern in which pixels PX to be printed are alternately arranged.

In this way, when one band image is printed by two partial printings, the arrangement pattern of pixels to be printed in each partial printing may be any pattern. Processor 210 may also identify pixels to be printed for each partial print without using mask data. For example, processor 210 may print each partial print using a function that returns the number of the partial print that ejects ink from a pixel location in the band image to that pixel location (eg, the number of the Jth partial print is J). A pixel of interest may be identified. In either case, processor 210 may control print execution unit 400 as follows. That is, in the second partial printing, the print execution unit 400 does not eject ink to the pixel positions where the ink protrudes in the first partial printing, and does not eject ink to the pixels where the ink did not protrude in the first partial printing. Ink is ejected to the position. More generally, the print execution unit 400 ejects ink to different pixels between multiple partial prints.

D. Variant:
(1) The supply condition of S360 (FIG. 6) may be any condition that indicates that the supply of at least one type of ink from the ink supply to the printhead may be delayed in partial printing. For example, instead of the cartridge replacement count, a cumulative value of the amount of ink used (for example, the amount of ink used expressed in units of milliliters) indicated by the print data may be used. In general, various values relating to the cumulative amount of ink used for printing in the print execution unit 400 may be used. Also, instead of the dot formation rate, an ink usage amount (for example, usage amount expressed in units of milliliters) calculated using the target band data may be used. In general, various values regarding ink usage calculated using target band data may be used. The supply condition includes a first index value, which is the amount of ink used for printing the target band image, which is the amount of ink used calculated using the target band data, and the Various conditions may be determined using at least one of a second index value, which is a value related to the cumulative amount of ink used for the head temperature, and the head temperature. For example, the determination threshold may be determined based on either the second index value (cumulative usage) or the head temperature, not both.

(2) In the above embodiment, when the supply condition is satisfied (Fig. 6: S360: Yes), one band image is printed by two partial printings. The process of performing the partial printing twice may be various processes. For example, the first partial print may print the upstream partial image, and the second partial print may print the downstream partial image. The printing order of the upstream partial image and the downstream partial image may be changed according to the operating state of the print executing unit 400 (for example, the position of the paper PM with respect to the sub-scanning unit 440). Similarly, the widths in the sub-scanning direction of the upstream partial image and the downstream partial image may be adjusted according to the operating state of the print executing section 400 .

Also, the end chromatic ink, which is the chromatic ink ejected from the end nozzle row, may be ink of another color (eg, yellow Y or cyan C) instead of magenta M ink. In either case, in S400 of FIG. 7, it may be determined whether or not the target ink is only the edge chromatic ink. In the process of FIG. 9, attention is focused not on the magenta M ink but on the edge chromatic ink. Here, one predetermined process out of S655-S660 and S680-S690 may be executed (the other process may be omitted), regardless of the target superposition order. S710-S725 of FIG. 10 may be executed instead of the processing of FIG. Note that the process of FIG. 9 for edge chromatic ink may be omitted. Here, if the determination result of S390 of FIG. 7 is No, the processor 210 may proceed to S710 of FIG.

Further, the processing for the black K ink ejected by the end nozzle row may be various processing. For example, instead of S540-S590 of FIG. 8, the processing of S710-S725 of FIG. 10 may be executed. Note that the processing for the black K ink may be omitted. For example, if the determination result of S380 of FIG. 7 is Yes, the processor 210 may proceed to S400. In this case, S390 and S540-S590 of FIG. 8 may be omitted.

Also, when the target ink includes the ink of the nozzle rows inside the nozzle rows at both ends in the main scanning direction ( FIG. 7 , S400: No), various processes may be executed. For example, the printing direction of the second partial printing may be opposite to the printing direction of the first partial printing.

(3) If the supply condition is satisfied (FIG. 6: S360: Yes), one band image may be printed by partial printing N times (N is an integer equal to or greater than 2). Here, the number of times N of partial printing may be 3 or more.

The method of distributing the ejection of the target ink over the N partial prints may be various other methods instead of the method of distributing the print pixels over the N partial prints. For example, when a large dot is to be recorded at one pixel position, the first partial printing records a medium dot at that pixel position, and the second partial printing records a medium dot at the same pixel position. good. In this way, a dot to be recorded may be divided into a plurality of dots of small size, and a plurality of dots may be recorded at the same pixel position by performing partial printing a plurality of times.

Also, as in the above embodiment, the processor 210 may perform N partial printings without transporting the paper PM. In this case, it is possible to suppress deviation of the dot formation positions on the paper PM due to the transportation of the paper PM between the N partial printings. Further, in the process of generating print data, correction (for example, ink amount correction) can be performed for each nozzle NZ according to the characteristics of each nozzle NZ. When partial printing is performed N times without conveying the paper PM, the nozzles NZ for forming ink dots in each print pixel are the same as the nozzles NZ for printing a band image in one partial printing. is. Therefore, N partial prints can form a dot at each print pixel according to the appropriately corrected print data. However, the paper PM may be transported between the N partial printings.

(4) Two adjacent band images may partially overlap each other in the overlap region extending in the main scanning direction. In the superimposed area, the arrangement of pixels included in each band image may be various arrangements. For example, the pixels of each band image may be arranged evenly.

Similarly, two adjacent partial images may partially overlap each other in the overlap region extending in the main scanning direction. In the superimposed area, the arrangement of pixels included in each partial image may be various arrangements. For example, the pixels of each partial image may be arranged evenly.

(5) The print process and the print execution process may be various other processes instead of the processes of the above embodiments and modifications. For example, the same color conversion profile may be used in color conversion processing regardless of the main scanning direction. Also, a plurality of band images may be printed by unidirectional printing instead of bidirectional printing. As a result, since the target superposition order is the same among a plurality of band images, it is possible to suppress the deviation of printed colors. In the process of FIG. 8, one of S555-S560 and S580-S590 in which the ink overlapping order is the same as the target overlapping order may be executed. Further, in the process of FIG. 9, one of S655-S660 and S680-S690 may be executed in which the ink overlapping order is the same as the target overlapping order.

(6) The configuration of the print execution unit 400 may be various other configurations instead of the configurations of the embodiments shown in FIGS. For example, the number L of types of ink that can be used may be any type greater than or equal to 2 (eg, L may be greater than or equal to 3). Also, the print head 410 may have L nozzle groups arranged side by side in the main scanning direction, which are L nozzle groups for ejecting L types of ink. It is preferable that the positions in the sub-scanning direction of the plurality of nozzles forming one nozzle group (that is, the plurality of nozzles for ejecting the same ink) are different from each other. In the embodiment of FIG. 3, a plurality of nozzles NZ of one nozzle group form one nozzle row. The positions in the main scanning direction are the same among a plurality of nozzles NZ of one nozzle row. Alternatively, the multiple nozzles NZ of one nozzle group may include multiple nozzles NZ at different positions in the main scanning direction. For example, a plurality of nozzles NZ in one nozzle group may form T (where T is an integer equal to or greater than 2) nozzle rows whose positions in the main scanning direction are different from each other. Here, one nozzle row is composed of a plurality of nozzles NZ whose positions in the sub-scanning direction are different from each other and whose positions are the same in the main scanning direction. In either case, the order in which the L types of ink are layered by partial printing is specified based on the order in which the L nozzle groups are arranged in the main scanning direction. Here, the order of arrangement (and thus arrangement) of the L nozzle groups in the main scanning direction may be determined arbitrarily. However, it is preferable that the nozzle group (for example, the nozzle row NK) that ejects the black K ink is arranged at the end in the main scanning direction. Then, if the target ink determined to be delayed in supply includes black K ink, as in S555-S560 or S585-S590 in FIG. It is preferably distributed over partial prints.

Also, the cartridge mounting portion 451 may be fixed to the carriage 433 . The pressing portion 445 may be omitted. Platen PT may be omitted. Two rollers configured to sandwich the paper PM may be utilized as upstream rollers. Also, two rollers configured to sandwich the paper PM may be used as the downstream rollers. The configuration of the sub-scanning section 440 may be any configuration configured to move the paper PM along the sub-scanning direction. For example, the sub-scanning unit 440 may include rollers that transport the print medium upstream or downstream of the print head. The configuration of the main scanning section 430 may be any configuration configured to move the print head along the main scanning direction with respect to the print medium. Also, the forward direction may be either one of the two-way main scanning directions. For example, the second direction D2 may correspond to the forward direction.

(7) In the above embodiments, the multi-function device 200 is an example of a printing device that includes the print execution unit 400 . Here, the scanner unit 280 may be omitted. The control unit 299 is an example of a control device of a printing device that includes the print execution unit 400 . Also, the control unit 299 is an example of a control device that controls the print execution unit 400 . The print data generation process (for example, the process in FIG. 5) is executed by the control device of the printing device (for example, the control unit 299 of the multifunction machine 200) instead of the external device (for example, the terminal device 100) connected to the printing device. may be executed. The print execution process (eg, the processes of FIGS. 6 to 10) may be executed by an external device (eg, terminal device 100) connected to the printing device instead of the control device of the printing device. In this case, the printing device is an example of a print execution unit, and the external device is an example of a control device that controls the printing device (and thus the print execution unit).

In either case, if the supply condition is satisfied, the control device performs image processing including halftone processing again instead of dividing the target band data, thereby printing the target band image. partial print data may be generated.

In each of the above embodiments, part of the configuration implemented by hardware may be replaced with software, or conversely, part or all of the configuration implemented by software may be replaced with hardware. good too. For example, the control unit 299 of the MFP 200 may be a dedicated hardware circuit for executing print execution processing.

In addition, when part or all of the functions of the present invention are realized by a computer program, the program is provided in a form stored in a computer-readable recording medium (for example, a non-temporary recording medium). be able to. The program can be used while being stored in the same or different recording medium (computer-readable recording medium) as when it was provided. "Computer-readable recording medium" is not limited to portable recording media such as memory cards and CD-ROMs, but also internal storage devices such as various ROMs in computers, and hard disk drives that are connected to computers. An external storage device may also be included.

Although the present invention has been described above based on examples and modifications, the above-described embodiments of the present invention are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The present invention may be modified and improved without departing from its spirit, and the present invention includes equivalents thereof.

DESCRIPTION OF SYMBOLS 100... Terminal device, 110... Processor, 115... Storage device, 120... Volatile storage device, 130... Non-volatile storage device, 132... Program, 140... Display part, 150... Operation part, 170... Communication interface, 200... Composite Machine 210 Processor 215 Storage device 220 Volatile storage device 230 Non-volatile storage device 232 Program 240 Display unit 250 Operation unit 270 Communication interface 280 Scanner unit 299 Control unit 300 Threshold table 310 Number of times of replacement table 321, 321a, 321b Mask data 321a1, 321b1 First mask pattern 321a2, 321b2 Second mask pattern 400 Print execution unit 410 Print head 411 Nozzle forming surface 420 Head driving unit 430 Main scanning unit 433 Carriage 434 Sliding shaft 435 Belt 436 Pulley 440 Sub scanning unit (conveying unit) 441 ...Upstream roller 442...Downstream roller 445...Pressure part 450...Ink supply part 451...Cartridge mounting part 452...Tube 453...Buffer tank 454K, 454Y, 454C, 454M...Cartridge sensor 460...Encoder, 461 linear scale 462 optical sensor 470 temperature sensor 490 control circuit 1000 image processing system LUT1 outward color conversion profile LUT2 return color conversion profile D1 first direction (outward direction), D2...Second direction (return direction), KC, YC, CC, MC...Ink cartridge, NC, NM, NY, NK...Nozzle row, PM...Paper, PT...Platen, NZ...Nozzle

Claims (13)

a print head having L nozzle groups arranged side by side in a main scanning direction for ejecting L types of ink (L is an integer equal to or greater than 2); an ink supply unit that supplies the L types of ink; a main scanning unit that performs a main scan for moving the print head along the main scanning direction with respect to the print medium; and the main scan with respect to the print head. a sub-scanning section that executes sub-scanning to move the print medium along a sub-scanning direction that intersects with the sub-scanning direction; To cause the print execution unit to print an image by performing partial printing in which ink is ejected to the print head while performing main scanning and causing the sub-scanning unit to perform the sub-scanning a plurality of times. wherein the control device of
A plurality of band images included in an image to be printed determine whether a supply condition indicating that supply of at least one type of ink from the ink supply unit to the print head in the partial printing is delayed is satisfied. a determination unit that determines each of the plurality of band images arranged in the sub-scanning direction;
a first print processing unit that causes the print execution unit to print the band image by causing the print execution unit to execute the partial print once when the supply condition is not satisfied;
a second print processing unit that causes the print execution unit to print the band image by causing the print execution unit to execute a multi- portion print process when the supply condition is satisfied;
with
The second print processing unit controls the supply conditions and the first end nozzle group in which the target ink determined to be delayed in supply is located at one end of the L nozzle groups in the main scanning direction. and a first multipart print process using the first end ink as the first ink of interest if a first condition is satisfied including: causing the print execution unit to execute
The first multiple-portion printing process includes:
In the first partial printing, causing the main scanning unit to perform the main scanning for moving the print head relative to the print medium in a direction in which the first ink of interest is superimposed in the L-th order. , partial printing in which the L types of ink are ejected to the print head;
the second partial printing, in which only the first ink of interest is ejected to the print head without ejecting L-1 kinds of inks other than the first ink of interest to the print head; and,
a controller, including The control device according to claim 1,
The second print processing unit
specifying the order of superimposition of the L types of ink by the one-time partial printing for the band of interest performed when the supply condition is not satisfied for the band of interest image;
When specific conditions including the supply condition, the first condition, and the condition that the order of the first end ink in the overlapping order of the inks is first for the band image of interest are satisfied, causing the print execution unit to execute a specific multi-portion print process using the first end ink as a specific target ink;
The specific multiple-portion printing process includes:
a moving process for causing the main scanning unit to move the print head relative to the print medium in a direction in which the specific ink of interest is superimposed first;
In the first partial printing performed after the movement process, only the specific target ink is ejected to the print head without causing the print head to eject L-1 types of ink other than the specific target ink. Partial printing to be discharged to
In the second partial printing, causing the main scanning unit to perform the main scanning for moving the print head relative to the print medium in a direction in which the specific ink of interest is placed first in the stacking order, Partial printing in which the L types of ink are ejected to the print head;
a controller, including The control device according to claim 1 or 2,
The second print processing unit controls the supply condition and the target ink determined to be delayed in supply to a second end nozzle located at the end on the other side in the main scanning direction among the L nozzle groups. a second multi-part printing using said second-end ink as a second ink of interest in a second case where certain conditions are satisfied including: a second condition that it is a second-end ink that is an ink of the group; cause the print execution unit to execute processing;
The second multiple-portion printing process includes:
the first partial printing, in which only the second ink of interest is ejected to the print head without ejecting L-1 kinds of inks other than the second ink of interest to the print head; and,
In the second partial printing, causing the main scanning unit to perform the main scanning for moving the print head relative to the printing medium in a direction in which the second ink of interest is superimposed first. , partial printing in which the L types of ink are ejected to the print head;
a controller, including The control device according to claim 3,
The second print processing unit determines that the main scanning direction in the first partial printing in the second case is different from the main scanning direction in the first partial printing in the first case. causing the print execution unit to execute the first partial printing in the first case and the first partial printing in the second case in opposite directions;
Control device. A control device according to claim 4,
The second print processing unit
specifying the order of superimposition of the L types of ink by the one-time partial printing for the band of interest performed when the supply condition is not satisfied for the band of interest image;
For the band image of interest, the first condition satisfying specific conditions including the supply condition, the first condition, and the condition that the order of the ink at the first end in the overlapping order of the inks is L is satisfied. , causing the print execution unit to execute the first multi-portion print process using the first end ink as the first ink of interest;
If the band image of interest satisfies a specific condition including the supply condition, the first condition, and the condition that the order of the first end ink in the order of overlapping of the inks is first, then the causing the print execution unit to execute the second multiple-portion printing process using the first end ink as the second ink of interest;
With respect to the band image of interest, the second condition satisfies a specific condition including the supply condition, the second condition, and the condition that the order of the ink at the second end in the overlapping order of the inks is first. , causing the print execution unit to execute the second multiple-portion printing process using the second end ink as the second ink of interest;
If the band image of interest satisfies specific conditions including the supply condition, the second condition, and the condition that the order of the ink at the second end in the overlapping order of the inks is L, then the causing the print execution unit to execute the first multi-portion print process using the second end ink as the first ink of interest;
Control device. a print head having L nozzle groups arranged side by side in a main scanning direction for ejecting L types of ink (L is an integer equal to or greater than 2); an ink supply unit that supplies the L types of ink; a main scanning unit that performs a main scan for moving the print head along the main scanning direction with respect to the print medium; and the main scan with respect to the print head. a sub-scanning section that executes sub-scanning to move the print medium along a sub-scanning direction that intersects with the sub-scanning direction; To cause the print execution unit to print an image by performing partial printing in which ink is ejected to the print head while performing main scanning and causing the sub-scanning unit to perform the sub-scanning a plurality of times. wherein the control device of
A plurality of band images included in an image to be printed determine whether a supply condition indicating that supply of at least one type of ink from the ink supply unit to the print head in the partial printing is delayed is satisfied. a determination unit that determines each of the plurality of band images arranged in the sub-scanning direction;
a first print processing unit that causes the print execution unit to print the band image by causing the print execution unit to execute the partial print once when the supply condition is not satisfied;
a second print processing unit that causes the print execution unit to print the band image by causing the print execution unit to execute a multi- portion print process when the supply condition is satisfied;
with
The second print processing unit sets the supply conditions and the ink of the end nozzle group, which is located at one end of the L nozzle groups in the main scanning direction, for which the supply can be delayed. and causing the print execution unit to execute a multiple-portion print process using the edge ink as the target ink when specific conditions are satisfied, and
The multiple part printing process includes:
a first partial printing in which only the ink of interest is ejected to the print head without ejecting L-1 types of ink other than the ink of interest to the print head;
In the second partial printing, the L Partial printing in which a type of ink is ejected onto the print head;
a controller, including A control device according to claim 6,
The multiple part printing process includes:
A process of causing the main scanning unit to move the print head relative to the print medium in a direction in which the ink of interest is stacked first before the first partial printing.
Control device. The control device according to any one of claims 1 to 7,
The second print processing unit determines the supply conditions and the target ink determined to be delayed in supply, among the L nozzle groups, positioned inside nozzle groups positioned at both ends in the main scanning direction. the first and second partial printings of the multiple partial printing process in which the direction of the main scanning is the same when a specific condition including a condition that the ink of the nozzle group including the causing the print execution unit to execute first and second partial printing of the multiple partial printing process in which L types of ink are ejected to the print head;
Control device. The control device according to any one of claims 1 to 8,
In the second partial printing of the multiple-part printing process, the second print processing unit does not eject the target ink to the pixel positions where the target ink was ejected in the first partial printing, and 1 ejecting the target ink to pixel positions where the target ink was not ejected in the partial printing of the second time;
Control device. A control device according to claim 9,
The second print processing unit refers to a predetermined mask pattern indicating pixel positions at which the target ink can be ejected in each of the first and second partial printings of the multiple-portion printing process , and prints the plurality of portions. specifying pixel positions where the target ink should be ejected in each of the first and second partial printings of the printing process ;
Control device. The control device according to any one of claims 1 to 10,
The ink of the nozzle group positioned at one end in the main scanning direction among the L nozzle groups is black ink.
Control device. a print head having L nozzle groups arranged side by side in a main scanning direction for ejecting L types of ink (L is an integer equal to or greater than 2); an ink supply unit that supplies the L types of ink; a main scanning unit that performs a main scan for moving the print head along the main scanning direction with respect to the print medium; and the main scan with respect to the print head. a sub-scanning unit that executes sub-scanning to move the print medium along a sub-scanning direction that intersects with the direction, the computer program for causing a print execution unit to print an image, wherein the main scanning unit By performing partial printing by causing the print head to eject ink while performing the main scanning and causing the sub-scanning unit to perform the sub-scanning a plurality of times, the print execution unit prints an image. A computer program for a computer that causes
A plurality of band images included in an image to be printed determine whether a supply condition indicating that supply of at least one type of ink from the ink supply unit to the print head in the partial printing is delayed is satisfied. a determination function for determining each of the plurality of band images arranged in the sub-scanning direction;
a first print processing function that causes the print execution unit to print the band image by causing the print execution unit to execute the partial print once when the supply condition is not satisfied;
a second print processing function that causes the print execution unit to print the band image by causing the print execution unit to execute a multi- portion print process when the supply condition is satisfied;
is realized on a computer,
The second print processing function includes the supply conditions and a first end nozzle group in which the target ink determined to be delayed in supply is positioned at one end of the L nozzle groups in the main scanning direction. and a first multipart print process using the first end ink as the first ink of interest if a first condition is satisfied including: causing the print execution unit to execute
The first multiple-portion printing process includes:
In the first partial printing, causing the main scanning unit to perform the main scanning for moving the print head relative to the print medium in a direction in which the first ink of interest is superimposed in the L-th order. , partial printing in which the L types of ink are ejected to the print head;
the second partial printing, in which only the first ink of interest is ejected to the print head without ejecting L-1 kinds of inks other than the first ink of interest to the print head; and,
computer programs, including a print head having L nozzle groups arranged side by side in a main scanning direction for ejecting L types of ink (L is an integer equal to or greater than 2); an ink supply unit that supplies the L types of ink; a main scanning unit that performs a main scan for moving the print head along the main scanning direction with respect to the print medium; and the main scan with respect to the print head. a sub-scanning unit that executes sub-scanning to move the print medium along a sub-scanning direction that intersects with the direction, the computer program for causing a print execution unit to print an image, wherein the main scanning unit By performing partial printing by causing the print head to eject ink while performing the main scanning and causing the sub-scanning unit to perform the sub-scanning a plurality of times, the print execution unit prints an image. A computer program for a computer that causes
A plurality of band images included in an image to be printed determine whether a supply condition indicating that supply of at least one type of ink from the ink supply unit to the print head in the partial printing is delayed is satisfied. a determination function for determining each of the plurality of band images arranged in the sub-scanning direction;
a first print processing function that causes the print execution unit to print the band image by causing the print execution unit to execute the partial print once when the supply condition is not satisfied;
a second print processing function that causes the print execution unit to print the band image by causing the print execution unit to execute a multi- portion print process when the supply condition is satisfied;
is realized on a computer,
The second print processing function is configured such that the supply condition and the ink of the end nozzle group that is located at one end of the L nozzle groups in the main scanning direction is the target ink that is determined to be delayed in supply. and causing the print execution unit to execute a multiple-portion print process using the edge ink as the target ink when specific conditions are satisfied, and
The multiple part printing process includes:
a first partial printing in which only the ink of interest is ejected to the print head without ejecting L-1 types of ink other than the ink of interest to the print head;
In the second partial printing, the L Partial printing in which a type of ink is ejected onto the print head;
computer programs, including

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