JP2021020419A - Control device, computer program, and method for controlling printing device - Google Patents

Abstract

To allow a printing device that can perform bidirectional printing to execute printing in an appropriate printing direction in accordance with image data that are used in the printing.SOLUTION: A control device executes: acquisition processing for acquiring corresponding target image data; determination processing for determining whether or not a color difference between an image printed in a first direction and an image printed in a second direction are equal to or above a criteria with respect to each of a plurality of partial images included in a printed image; decision processing for deciding respective printing directions of the partial images on the basis of determined results in the determination processing; and printing processing for making a printing head, a main-scanning part and a sub-scanning part to execute partial-printing and sub-scanning in the decided printing directions multiple times. In the determination processing, when the target image data are image data of a first kind, it is determined that the color difference is equal to or above the criteria when a first condition is satisfied, and when the target image data are image data of a second kind, it is determined that the color difference is equal to or above the criteria when a second condition is satisfied.SELECTED DRAWING: Figure 6

Description

The present specification relates to the control of a printing apparatus that prints by performing partial printing and sub-scanning that form dots while performing main scanning a plurality of times.

Patent Document 1 discloses a printer that prints a band image by ejecting ink from the print head while moving the print head in the forward or reverse direction of the main scanning direction. In this printer, the evaluation value regarding the difference between the color of the image printed in the forward direction and the color of the image printed in the reverse direction is calculated for each band image. The printer prints the band image in the forward direction when the evaluation value satisfies a predetermined condition indicating that the color difference is large, and prints the band image immediately before when the evaluation value does not satisfy the predetermined condition. Print in the direction opposite to the printing direction of the band image. As a result, it is said that the difference between the color of the image printed in the forward direction and the color of the image printed in the reverse direction can be suppressed from being noticeable, and the printing speed can be improved.

JP-A-2017-39205

However, the appropriate printing direction may differ depending on the image data used for printing because the required quality and printing speed differ. In the above technique, no consideration is given to the type of image data used for printing. For this reason, depending on the image data used for printing, printing may not be executed in an appropriate printing direction.

The present specification discloses a technique capable of performing printing in an appropriate printing direction according to image data used for printing in a printing apparatus capable of bidirectional printing.

The techniques disclosed herein can be realized as the following application examples.

[Application Example 1] A first-class nozzle that ejects first-color ink and a second-class nozzle that ejects second-color ink and has a different position in the main scanning direction from the first-class nozzle. A print head having a print head, a main scanning unit that executes a main scan for moving the print head along the main scan direction with respect to the print medium, and a sub-scan direction intersecting the main scan direction with respect to the print head. A control device for a printing device including a sub-scanning unit that executes a sub-scanning for relatively moving the print medium along the printing medium, and an image acquisition process for acquiring target image data corresponding to the print image, and the target image. Using the data, each of the plurality of partial images included in the printed image is printed in the first direction along the main scanning direction and in the second direction opposite to the first direction. The determination process for determining whether or not the color difference between the images is equal to or greater than the reference, and the printing directions of the plurality of partial images are determined in the first direction and the second direction based on the determination in the determination process. While performing the determination process for determining either of the above and the main scanning in the determined printing direction, at least one of the first type nozzle and the second type nozzle of the print head of the first color Partial printing in which the partial image is printed by ejecting at least one of the ink and the ink of the second color and the sub-scanning are performed by using the target image data to perform the printing head, the main scanning unit, and the sub-scanning. A printing process for causing the sub-scanning unit to execute a plurality of times is executed, and in the determination process, when the target image data is the first type of image data, the color difference is used as a reference when the first condition is satisfied. If the target image data is the second type of image data, it is determined that the color difference is equal to or greater than the reference when the second condition different from the first condition is satisfied. Control device.

When printing is performed in both the first direction and the second direction, the printing speed is increased, but this is caused by the color difference between the image printed in the first direction and the image printed in the second direction. Image quality is likely to deteriorate. When printing is performed in one of the first direction and the second direction, the deterioration of the image quality due to the color difference can be suppressed, but the printing speed is reduced. According to the above configuration, a process of determining whether or not the color difference between the image printed in the first direction and the image printed in the second direction opposite to the first direction is equal to or greater than the reference is executed. Based on the determination, the printing direction is determined to be either the first direction or the second direction. Then, in the determination process, when the target image data is the first type image data, it is determined that the color difference is equal to or more than the reference when the first condition is satisfied, and the target image data is the second type image data. In the case of, it is determined that the color difference is equal to or more than the reference when the second condition different from the first condition is satisfied. As a result, in a printing apparatus capable of printing (bidirectional printing) using partial printing in the first direction and the second direction, printing can be executed in an appropriate printing direction according to the image data used for printing. For example, printing can be performed in an appropriate printing direction so that an appropriate image quality and printing speed can be achieved according to the image data.

The techniques disclosed in the present specification can be realized in various forms, for example, a method for controlling a printing device, a computer program for realizing the functions of these devices and methods, and recording the computer program. It can be realized in the form of a recording medium or the like.

It is a block diagram which shows the structure of the multifunction device 10 of 1st Example. It is a figure which shows the schematic structure of the printing apparatus 200. It is explanatory drawing of the operation of the printing apparatus 200. It is explanatory drawing of the 1st color evaluation table CP1. It is a flowchart of print control processing. It is a flowchart of evaluation condition determination processing. It is a flowchart of a print direction determination process. It is explanatory drawing of a partial image and a plurality of blocks.

A. First Example A-1. Configuration of the multifunction device Next, an embodiment will be described based on an embodiment. FIG. 1 is a block diagram showing a configuration of the multifunction device 10 of the first embodiment.

The multifunction device 10 includes a control device 100, a printing device 200, and a reading device 300. The control device 100, the printing device 200, and the reading device 300 are connected to each other so as to be able to communicate with each other via a bus.

The control device 100 controls the printing device 200 and the reading device 300. The control device 100 includes a CPU 110, a non-volatile storage device 120 such as a hard disk drive and a flash memory, a volatile storage device 130 such as a RAM, an operation unit 140 such as a touch panel and buttons, and a liquid crystal display superimposed on the touch panel. The display unit 150, the wired network interface (IF) 160, the wireless network interface (IF) 170, the USB interface (IF) 180, and the telephone line interface (IF) 190 are provided.

The wired network IF160 is, for example, a wired interface compliant with the Ethernet (registered trademark) standard. The wireless network IF170 is, for example, a wireless interface compliant with the Wi-fi standard. The control device 100 is communicably connected to the terminal device via these networks IFs 160 and 170. The terminal device is, for example, a personal computer (PC) 30 or a smartphone 40 used by a user of the multifunction device 10.

The USB IF 180 is an interface for performing data communication in accordance with the USB (Universal Serial Bus) standard, which is one of the serial bus standards. The control device 100 is connected to the USB memory 50 as the removable memory via, for example, the USB IF 180.

The telephone line IF190 is, for example, a two-wire or four-wire analog telephone line interface, and is used for connecting to the analog telephone line network 60, that is, the PSTN (Public Switched Telephone Network).

The volatile storage device 130 provides a buffer area 131 that temporarily stores various intermediate data generated when the CPU 310 performs processing. The non-volatile storage device 120 stores a computer program PG, color conversion profiles PF1 and PF2, and color evaluation tables CP1 and CP2. The computer program PG, the color conversion profiles PF1 and PF2, and the color evaluation tables CP1 and CP2 are provided by the manufacturer of the multifunction device 10 in a form downloaded from a server or stored in a DVD-ROM or the like, for example. Will be done. The CPU 110 controls the multifunction device 10 by executing the computer program PG. For example, the CPU 110 controls the reading device 300 to cause the reading device 300 to generate scan data. Further, the CPU 110 executes a print control process described later to cause the printing device 200 to print an image. The color evaluation tables CP1 and CP2 will be described later.

The color conversion profiles PF1 and PF2 are profiles that define the correspondence between the RGB values and the MYK values, respectively. The color conversion profiles PF1 and PF2 are used for the color conversion process of converting the RGB value into the CMYK value in the print control process described later. The RGB values include three component values of red (R), green (G), and blue (B). The CMYK values include a plurality of component values corresponding to a plurality of types of inks used for printing, and in this embodiment, component values of cyan (C), magenta (M), yellow (Y), and black (K). .. The RGB value and the CMYK value are, for example, 256 gradation values. The color conversion profiles PF1 and PF2 are, for example, look-up tables.

The first color conversion profile PF1 is used for the color conversion process executed in the print control process when printing other than copying is performed. The second color conversion profile PF2 is used for the color conversion process executed in the print control process when printing for copying is performed.

The image quality required for a printed image differs between printing other than copying and printing for copying. For this purpose, in this embodiment, two types of color conversion profiles PF1 and PF2 that are different from each other are prepared. For example, the first color conversion profile PF1 is adjusted so as to approach the stored color in the printed image rather than faithfully expressing the color of the image indicated by the image data before the color conversion processing. The memory color is the color of an object stored in the human brain (eg, blue in the sky). The second color conversion profile PF2 is adjusted so that the colors of the original can be reproduced in the printed image. This is to suppress the inconvenience of printing an image having a color significantly different from the color of the original original when the printed image printed by copying is repeatedly copied.

The printing apparatus 200 can form dots on the paper M using the respective inks (droplets) of cyan (C), magenta (M), yellow (Y), and black (K), thereby performing color printing. I do. The printing apparatus 200 includes a printing head 210, a head driving unit 220, a main scanning unit 230, a transport unit 240, and an ink supply unit 250.

FIG. 2 is a diagram showing a schematic configuration of the printing apparatus 200. As shown in FIG. 2A, the main scanning unit 230 includes a carriage 233, a sliding shaft 234, a belt 235, and a plurality of pulleys 236 and 237. The carriage 233 carries a print head 210. The sliding shaft 234 holds the carriage 233 in a reciprocating manner along the main scanning direction (X-axis direction in FIG. 2A). The belt 235 is wound around the pulleys 236 and 237, and a part of the belt 235 is fixed to the carriage 233. The pulley 236 is rotated by the power of a main scanning motor (not shown). When the main scanning motor rotates the pulley 236, the carriage 233 moves along the sliding shaft 234. As a result, the main scanning in which the print head 210 is reciprocated along the main scanning direction with respect to the paper M is realized.

The transport unit 240 transports the paper M in the transport direction (-Y direction in FIG. 2A) while holding the paper M. Hereinafter, the upstream side (+ Y side) in the transport direction is also simply referred to as an upstream side, and the downstream side (−Y side) in the transport direction is also simply referred to as a downstream side. Although detailed illustration is omitted, the transport unit 240 includes an upstream roller pair that holds the paper M on the upstream side of the print head 210, a downstream roller pair that holds the paper M on the downstream side of the print head 210, and a motor. And. The transport unit 240 transports the paper M by driving these rollers with the power of a motor.

The ink supply unit 250 supplies ink to the print head 210. The ink supply unit 250 includes a cartridge mounting unit 251 and a tube 252. A plurality of ink cartridges MC, CC, YC, and KC, which are containers containing ink inside, are detachably mounted on the cartridge mounting portion 251, and ink is supplied from these ink cartridges. The ink in each ink cartridge is supplied to the print head 210 via the cartridge mounting portion 251 and the tube 252.

FIG. 2B is a diagram showing the configuration of the print head 210 as viewed from the −Z side. As shown in FIG. 2B, the nozzle forming surface 111 of the print head 210 is a surface facing the paper M transported by the transport unit 240. A plurality of nozzle rows composed of a plurality of nozzles NZ, that is, nozzle rows NK, NY, NC, and NM for ejecting each of the above-mentioned C, M, Y, and K inks are formed on the nozzle forming surface 111. Each nozzle row contains a plurality of nozzles NZ. The plurality of nozzles NZ are located at different positions in the transport direction (−Y direction), and are lined up at a predetermined nozzle interval NT along the transport direction. The nozzle spacing NT is the length in the transport direction between two nozzles NZ adjacent to each other in the transport direction among the plurality of nozzles NZ. Among the nozzles constituting these nozzle rows, the nozzle NZ located on the most upstream side (+ Y side) is also referred to as the most upstream nozzle NZu. Further, among these nozzles, the nozzle NZ located on the most downstream side (−Y side) is referred to as 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 referred to as a nozzle length D.

The positions of the nozzle rows NK, NY, NC, and NM in the main scanning direction (positions in the X direction) are different from each other, and the positions in the sub scanning direction overlap each other. For example, in the example of FIG. 2B, the nozzle rows NK, NY, NC, and NM are arranged in this order from the upstream side to the downstream side in the X direction.

Each nozzle NZ is connected to an ink flow path (not shown) formed inside the print head 210. An actuator (not shown, piezoelectric element in this embodiment) for ejecting ink along each ink flow path inside the print head 210 is provided.

The head drive unit 220 (FIG. 1) drives each actuator in the print head 210 according to the print data supplied from the control device 100 during the main scan by the main scan unit 230. As a result, ink is ejected from the nozzle NZ of the print head 210 onto the paper M conveyed by the conveying unit 240, and dots are formed. The head drive unit 220 can form dots of a plurality of sizes on the paper M by changing the drive voltage supplied to the actuator.

The scanning device 300 optically scans the document using an image sensor to generate scan data indicating a scanned image including the document. The image sensor is, for example, a one-dimensional image sensor having a structure in which a plurality of photoelectric conversion elements such as a CCD and CMOS are arranged side by side in a row. The scan data is, for example, RGB image data representing a color for each pixel by an RGB value. The RGB value is, for example, a color value including three component values of red (R), green (G), and blue (B).

A-2. Outline of Printing The printing device 200 prints a printed image OI on paper M by alternately executing partial printing and sub-scanning a plurality of times under the control of the control device 100. Partial printing is performed by ejecting ink from at least a part of a plurality of nozzles NZ of the print head 210 while performing main scanning by the main scanning unit 230. By partial printing, dots are formed on the paper M, and a partial image (described later) of the printed image OI is printed on the paper M.

FIG. 3 is an explanatory diagram of the operation of the printing device 200. 3 (A) to 3 (C) show the printed image OI printed on the paper M. The printed image OI includes a plurality of partial images. In the example of FIG. 3, the printed image OI includes partial images PI1 to PI5. Each partial image is an image printed by one partial printing. The printing direction of partial printing is either the outward direction or the return direction. That is, in the partial printing, the outbound printing that forms dots while performing the main scan in the outward direction (-X direction in FIG. 3) and the return route that forms dots while performing the main scan in the inbound direction (+ X direction in FIG. 3). Either printing or. In FIG. 3, a solid arrow in the + X direction or the −X direction is attached in the partial image. The partial image (for example, PI1, PI3, PI5 in FIG. 3A) with a solid arrow in the −X direction is an outward partial image printed by outbound printing. The partial image (for example, PI2 and PI4 in FIG. 3A) with a solid arrow in the + X direction is a return partial image printed by the return print.

In FIG. 3, an arrow in the + Y direction from one partial image (for example, partial image PI1) toward another partial image (for example, partial image PI2) adjacent in the + Y direction indicates paper M transport (sub-scanning). It corresponds to. That is, the arrow in the + Y direction in FIG. 3 indicates that the print head 210 moves in the + Y direction with respect to the paper M shown in FIG. 3 as the paper M is conveyed. As shown in FIG. 3, the printing of this embodiment is so-called one-pass printing, and the length of each partial image in the transport direction and the transport amount of the paper M at one time are the nozzle length D.

The printed image OI is printed using either bidirectional printing or unidirectional printing. Bidirectional printing is printing performed by combining outbound printing and inbound printing. There are two types of bidirectional printing: full bidirectional printing in FIG. 3 (A) and partial bidirectional printing in FIG. 3 (B). Full bidirectional printing is printing in which outbound printing and inbound printing are executed alternately, and outbound printing is not executed continuously or inbound printing is not executed continuously. Partial bidirectional printing is printing in which both outbound printing and inbound printing are executed, but outbound printing may be executed continuously. For example, in the example of FIG. 3B, the partial images PI3 and PI4 are printed by two consecutive outbound prints. One-way printing is printing performed only by outbound printing. Alternatively, the one-way printing may be printing performed only by the return printing.

In each embodiment of the present specification, the print resolution and the number of passes for bidirectional printing are equal to the print resolution and the number of passes for unidirectional printing. The number of passes is the number of partial prints performed when printing each area of the printed image OI. In this embodiment, both bidirectional printing and unidirectional printing are one-pass printing in which one partial image is printed by only one partial printing (number of passes = 1). Further, the print resolutions in the X and Y directions of bidirectional printing are equal to the print resolutions in the X and Y directions of one-way printing.

When partial printing in the same printing direction is continuously performed, the main scan is performed between two consecutive partial printings without forming dots. The main scan performed without forming dots (that is, without printing a partial image) in this way is also referred to as a non-print main scan. The dashed arrows in FIGS. 3 (B) and 3 (C) indicate the non-printing main scan. For example, in FIG. 3B, a non-printing main scan is performed between the outbound printing for printing the partial image PI3 and the outbound printing for printing the partial image PI4. In the one-way printing of FIG. 3C, the non-printing main scan is performed every time the outbound printing is performed. Since the printing time required for printing is longer due to the non-printing main scanning than when the non-printing main scanning is not performed, the printing speeds are full bidirectional printing, partial bidirectional printing, and one-way printing. Faster in order of printing.

Here, as shown in FIG. 2B, as shown in the print head 210, the positions of the CMYK nozzle rows NC, NM, NY, and NK are different from each other in the main scanning direction. Therefore, when the CMYK dots are formed at the same position on the paper M, the dot formation order is different between the outbound printing and the inbound printing. For example, in the example of FIG. 2B, dots are formed in the order of K, Y, C, and M in the outbound printing, and conversely, dots are formed in the order of M, C, Y, and K in the inbound printing. Will be printed. As a result, in the region where dots of a plurality of colors overlap, the order in which the dots overlap differs between the outward path partial image and the return path partial image. Therefore, even if the outbound partial image and the inbound partial image are printed using the same dot data, the printed colors may be different from each other. The phenomenon in which the color to be printed differs between the outward partial image and the return partial image is hereinafter referred to as a round-trip color difference.

The color evaluation tables CP1 and CP2 are tables in which information regarding the degree of color difference between round trips is recorded. Specifically, the color evaluation tables CP1 and CP2 are lookup tables that define weights indicating the degree of color difference between round trips for each of the RGB values. The color evaluation tables CP1 and CP2 are used in the print control process described later. The first color evaluation table CP1 is used when printing other than copying is performed, and the second color evaluation table CP2 is used when printing for copying is performed.

FIG. 4 is an explanatory diagram of the first color evaluation table CP1. FIG. 4A shows an RGB color space CC, which is an RGB color space. Each of the eight vertices of the RGB color space CC has a code indicating a color (specifically, a black vertex Vk (0,0,0), a red vertex Vr (255,0,0), and a green vertex Vg (0,0,0). 255,0), blue apex Vb (0,0,255), cyan apex Vc (0,255,255), magenta apex Vm (255,0,255), yellow apex Vy (255,255,0), white The vertices Vw (255, 255, 255)) are attached. The numbers in parentheses indicate the values of each color component (R, G, B). The R value of each grid GD is one of Q + 1 values obtained by dividing the range of R (here, from zero to 255) into Q equal parts. The same applies to the respective values of green G and blue B of each grid GD. In this embodiment, since Q = 9, 9 cubes (729) of grid GDs are set in the RGB color space CC.

FIG. 4B shows an example of the first color evaluation table CP1. In the first color evaluation table CP1, a weight Wt is associated with each of the RGB values corresponding to the 729 grid GDs. For example, the evaluator obtains a color patch printed based on the CMYK values obtained by converting the RGB values of a specific grid GD using the first color conversion profile PF1 and the RGB values of the grid GD. A color patch to be printed based on a CMYK value obtained by conversion using the one-color conversion profile PF1 is printed. The evaluator measures the color of the two color patches and acquires the color measurement value. The color measurement value is, for example, a color value in a color space that does not depend on a device such as a printing device 200, and in this embodiment, a color value in the CIELAB color space (hereinafter, also referred to as a Lab value). The evaluator calculates the color difference between the two acquired colorimetric values as the round-trip color difference corresponding to the specific grid GD. The evaluator determines a weight Wt that is larger as the color difference between round trips is larger as a weight Wt that corresponds to a specific grid GD. In this way, the weight Wt associated with the 729 grid GDs is determined, and the first color evaluation table CP1 is created.

As described above, the color difference between the round trips is due to the difference in the order in which the dots overlap between the outward route partial image and the return route partial image. For this reason, among the C, M, Y, and K inks used for printing, the color difference between reciprocations becomes large for a specific color (also referred to as a color difference-generating color) expressed by using two types of inks. The color difference-generating color includes, for example, green expressed using both C ink and Y ink, and particularly dark green expressed using both C ink and Y ink in a relatively large amount. Further, the color difference generation color is expressed by using red expressed by using both M ink and Y ink, and blue, C, M, and Y ink expressed by using both C ink and M ink. May include gray. In the first color evaluation table CP1, the grid GD corresponding to these color difference occurrence colors is associated with a weight Wt larger than that of the grid GD corresponding to other colors. Further, the primary color expressed by using only one type of ink among the C, M, Y, and K inks is expressed without overlapping of a plurality of types of inks on the paper. Therefore, for the primary color, there is no color difference between the round trips. Therefore, "0" is associated with the grid GD corresponding to the primary color as the weight Wt.

Similar to the first color evaluation table CP1, the second color evaluation table CP2 has a weight Wt associated with each of the RGB values corresponding to the 729 grid GDs. The second color evaluation table CP2 is created in the same manner as the first color evaluation table CP1. However, when printing the color patch at the time of creating the second color evaluation table CP2, the second color conversion profile PF2 is used instead of the first color conversion profile PF1. Therefore, the weight Wt corresponding to each grid GD is different between the first color evaluation table CP1 and the second color evaluation table CP2.

A-3. Operation of printing system 1000 A-3-1. Print control process The CPU 110 (FIG. 1) of the control device 100 causes the print device 200 to print the print image OI using the target image data corresponding to the print image OI by executing the print control process. FIG. 5 is a flowchart of the print control process.

In S5, the CPU 310 acquires the target image data. In this embodiment, the target image data is acquired in the following five patterns. The target image data to be acquired is, for example, dot data or RGB image data. When the target image data is neither dot data nor RGB image data (for example, when the data is described in a predetermined page description language), rasterization processing is executed and the data is converted into RGB image data.

(1) In the first pattern, the target image data is acquired from the personal computer 30. The driver program DP (FIG. 1) is installed as an application program on the personal computer 30. The driver program DP is provided, for example, by the manufacturer of the multifunction device 10. The CPU of the personal computer 30 (not shown) functions as a printer driver by executing the driver program DP. The printer driver, for example, generates dot data using image data specified by the user. Specifically, the printer driver rasterizes the image data to generate RGB image data. The printer driver executes color conversion processing on RGB image data to generate CMYK image data. The CMYK image data is image data representing the color of each pixel by the above-mentioned CMYK value. The above-mentioned first color conversion profile PF1 is incorporated in the driver program DP, and the printer driver executes the color conversion process using the first color conversion profile PF1. The printer driver executes halftone processing on the CMYK image data to generate dot data. The halftone process is performed using a known method, for example, an error collection method. The generated dot data is data indicating a dot formation state for each color component (for each CMYK component in this embodiment) and for each pixel. The dot formation state is, for example, one of "with dots" and "without dots". Instead of this, the dot formation state may be any one of "large dot", "medium dot", "small dot", and "no dot". The value of each pixel of the CMYK image data and the dot data includes a component value corresponding to the CMYK ink used for printing. Therefore, it can be said that the CMYK image data and the dot data are image data including the color values of the CMYK color system for each pixel. As described above, in the first pattern, the target image data is dot data transmitted from the personal computer 30 (printer driver). For example, the CPU 110 of the control device 100 acquires the dot data via the wired network IF160.

(2) In the second pattern, the target image data is acquired from the smartphone 40. A print application program AP for mobile terminals is installed on the smartphone 40 as an application program. The CPU of the smartphone 40 (not shown) functions as a print application by executing the print application program AP. The print application program AP is provided by a business operator different from the manufacturer of the multifunction device 10, for example, the manufacturer of the smartphone 40 or the OS (Operating System) provider of the smartphone 40. The print application, for example, converts the image data specified by the user into a predetermined data format, compresses the image data in a predetermined compression format, and transmits the image data to the multifunction device 10. As described above, in the second pattern, the target image data is the image data transmitted from the smartphone 40 (print application). For example, the CPU 110 of the control device 100 acquires the image data via the wireless network IF170.

(3) In the third pattern, the target image data is the image data stored in the USB memory 50 as the removable memory. In the third pattern, the CPU 110 of the control device 100 acquires the target image data by reading the target image data from the USB memory 50 connected to the USB IF 180 via the USB IF 180. Although not shown, the target image data acquired by reading from another removable memory such as an SD card or CompactFlash (registered trademark) is also applicable to the third pattern, not limited to the USB memory 50.

(4) In the fourth pattern, the target image data is facsimile data. The facsimile data is, for example, image data compressed according to a standard such as FAXG3. In the fourth pattern, the CPU 110 of the control device 100 receives facsimile data as target image data from a device (not shown) connected to the network 60 of the analog telephone line via the telephone line IF190. To get. Facsimile data is generally monochromatic dot data containing only one component value for each pixel.

(5) In the fifth pattern, the target image data is scan data generated by the reading device 300. In the fifth pattern, the CPU 110 of the control device 100 controls the reading device 300 based on the user's instruction to cause the reading device 300 to read the document and generate scan data, whereby the scan data as the target image data. To get.

The fifth pattern is a pattern in which printing for copying described above is performed, and the first to fourth patterns are patterns in which printing different from copying is performed.

In S10, the CPU 110 executes the evaluation condition determination process. The evaluation condition determining process determines the evaluation condition used when evaluating the degree of the reciprocating color difference of the attention portion image in the printing direction determining process (S25, FIG. 7) described later. The evaluation condition determination process will be described later.

In S15, the CPU 110 controls the transport unit 240 to feed paper. Paper feeding is a control for transporting one sheet of paper M from a paper tray (not shown) to a predetermined initial position.

In S20, the CPU 110 selects the partial image data for one partial print among the target image data as the attention partial image data. The partial image corresponding to the attention partial image data is also referred to as a attention partial image. Further, partial printing for printing a attention partial image is also referred to as attention partial printing.

In S25, the CPU 110 executes a print direction determination process for determining the print direction (also referred to as the attention print direction) for the partial print of interest. The print direction determination process is a process of determining the print direction of interest as either the outward direction or the return direction. The printing direction determination process will be described later.

In S30, the CPU 110 determines whether or not the partial image data of interest is dot data. When the target image data acquired in S5 is CMYK dot data acquired in the first pattern described above, or when it is facsimile data (monochromatic dot data) acquired in the fourth pattern. , The attention partial image data is determined to be dot data. When the target image data acquired in S5 is CMYK dot data acquired in the first pattern described above, or when it is facsimile data (monochromatic dot data) acquired in the fourth pattern. , The partial image data of interest is determined to be image data different from the dot pattern.

When the attention partial image data is image data different from the dot data (S30: NO), that is, when the attention partial image data is RGB image data, in S40, the CPU 110 determines the attention partial image data. A color conversion process is executed on (RGB image data) to convert the attention portion image data into CMYK image data. When the target image data acquired in S5 is the scan data acquired in the fifth pattern described above, the color conversion process is executed using the second color conversion profile PF2 for copying. When the target image data acquired in S5 is the image data acquired in the second and third patterns described above, the color conversion process is executed using the first color conversion profile PF1.

In S45, the CPU 110 executes halftone processing on the color-converted attention portion image data (CMYK image data) to generate partial print data for attention portion printing. The halftone process is performed using a known method, for example, an error collection method. As described above, the partial print data is dot data indicating a dot formation state for each color component and each pixel.

When the attention partial image data is dot data (S30: YES), the CPU 110 skips S40 and S45 and proceeds to S50. In this case, since the attention partial image data is dot data, the attention partial image data is used as it is as the partial print data for the attention partial print.

In S50, the CPU 110 drives the main scanning unit 230 and the head of the printing apparatus 200 by using the partial print data for the partial print of interest and the direction information indicating the print direction of interest determined by the print direction determination process. Part 220 is controlled to execute partial printing. For example, the printing device 200 executes outbound printing when the direction information indicates the outbound direction, prints a partial image of interest, and executes inbound printing when the direction information indicates the inbound direction. Print the attention area image.

In S55, the CPU 110 controls the transport unit 240 of the printing apparatus 200 to transport the paper M. For example, the paper M is conveyed by the nozzle length D.

In S60, the CPU 110 determines whether or not all the partial image data included in the target image data has been processed. If there is unprocessed partial image data (S60: NO), the CPU 110 returns the processing to S20. When all the partial image data has been processed (S60: YES), in S65, the CPU 110 controls the transport unit 240 of the printing apparatus 200 to eject the paper M to the output tray (not shown). To do. When the paper is ejected, the print control process is terminated.

A-3-2. Evaluation condition determination process The evaluation condition determination process of S10 of FIG. 5 will be described. As described above, the evaluation condition determination process is a process of determining the evaluation condition used when evaluating the degree of the reciprocating color difference of the partial image of interest in the print direction determination process (S25, FIG. 7). The evaluation conditions to be determined are a color evaluation table (also called a usage table) to be used when calculating the evaluation value EV (described later) and a threshold value (also called a usage threshold) to be used for comparison with the evaluation value EV. There are two types.

FIG. 6 is a flowchart of the evaluation condition determination process. In S100, the CPU 110 determines whether or not the target image data acquired in S5 of FIG. 5 is the scan data acquired in the fifth pattern described above. In other words, in this step, it is determined whether or not the printing based on the target image data is printing for copying.

When the target image data is scan data (S100: YES), in S105, the CPU 110 determines the second color evaluation table CP2 for copying as the table to be used. In S110, the CPU 110 determines the copy threshold THs as the usage threshold.

When the target image data is different from the scan data (S100: NO), in S115, the CPU 110 determines the first color evaluation table CP1 as the table to be used.

In S120, the CPU 110 determines whether or not the target image data acquired in S5 of FIG. 5 is facsimile data acquired in the fourth pattern described above. In other words, in this step, it is determined whether or not the printing based on the target image data is the printing based on the receipt of the facsimile data.

When the target image data is facsimile data (S120: YES), in S125, the CPU 110 determines the threshold value for fax THf as the usage threshold value.

When the target image data is different from the facsimile data (S120: NO), in S130, the CPU 110 uses the image data acquired from the USB memory 50 of the third pattern described above as the target image data. Determine if it exists. In other words, in this step, whether or not the printing based on the target image data is the printing based on the image data (also referred to as media printing) directly acquired from the removable memory (also referred to as removable media) such as the USB memory 50. Is judged.

When the target image data is the image data acquired from the USB memory (S130: YES), in S135, the CPU 110 determines the threshold value THm for media printing as the usage threshold value.

When the target image data is different from the image data acquired from the USB memory (S130: NO), in S140, the CPU 110 acquires the target image data in the first pattern described above. It is determined whether or not the dot data includes the component values of CMYK. In other words, in this step, whether or not printing based on the target image data is printing based on dot data (also referred to as driver printing) transmitted from a terminal device (for example, a personal computer 30) that functions as a printer driver. Is judged.

When the target image data is dot data including CMYK component values (S140: YES), in S145, the CPU 110 determines the threshold value THd for driver printing as the usage threshold value.

When the target image data is different from the dot data including the component values of CMYK (S140: NO), in this embodiment, the target image data is the image data acquired in the second pattern. As described above, the printing based on the image data acquired in the second pattern is printing based on the image data transmitted from the terminal device (for example, the smartphone 40) that functions as a print application (also referred to as application printing). .. Therefore, in this case, in S150, the CPU 110 determines the threshold value THa for printing the application as the usage threshold value.

When the usage table and the usage threshold are determined, the evaluation condition determination process is terminated. The threshold value THd for driver printing, the threshold value THs for copying, the threshold value THa for application printing, the threshold value THm for media printing, and the threshold value THF for fax are THd> THs> THa> THm> THf. Meet the relationship. The reason for this will be described later.

A-3-3. Print direction determination process The print direction determination process of S25 of FIG. 5 will be described. As described above, the evaluation condition determination process is a process of determining the print direction of interest as either the outward direction or the return direction. FIG. 7 is a flowchart of the printing direction determination process.

In S210, the CPU 110 divides the attention partial image into a plurality of blocks BL. FIG. 8 is an explanatory diagram of a partial image and a plurality of blocks. In the example of FIG. 8, the partial image PI2 is divided into a plurality of blocks BL as the partial image of interest. The shape of the block BL is rectangular. The plurality of blocks BL are arranged in a grid pattern without gaps along the main scanning direction (X direction in FIG. 8) and the transport direction (Y direction in FIG. 8). The height BH in the transport direction of the block BL and the width BW in the main scanning direction are predetermined.

In S215, the CPU 110 selects one unprocessed block BL among the plurality of block BLs of the partial image of interest as the block of interest.

In S220, the CPU 110 calculates the evaluation value EV of the attention block by using the table determined as the table to be used in the evaluation condition determination process among the color evaluation tables CP1 and CP2. The evaluation value EV indicates the degree of color difference (the above-mentioned reciprocating color difference) between the image printed when the partial printing of interest is performed in the outward direction and the image printed when the partial printing is performed in the return direction. The value. Specifically, when the attention partial image data is RGB image data, the CPU 110 uses a plurality of pixel values (RGB values) of the plurality of pixels included in the attention block and a usage table to obtain a plurality of pixels. Each weight Wt of the pixel is specified. When the attention partial image data is CMYK image data, the CPU 110 converts the pixel values (CMYK values) of the plurality of pixels included in the attention block into RGB values using the first color conversion profile PF1. Then, the weight Wt of each of the plurality of pixels is specified by using the RGB value and the usage table. For example, among a plurality of grid GDs (FIG. 4A) in the usage table, the grid GD closest to the value (RGB value) of a specific pixel is specified, and the weight associated with the grid GD in the usage table is specified. Wt is defined as the weight Wt of the specific pixel. Then, the CPU 110 calculates the average value of the weights Wt of the plurality of pixels as the evaluation value EV of the attention block. When the partial image data of interest is dot data (in the case of the first pattern described above), the CPU 110 acquires RGB image data corresponding to the dot data from the personal computer 30 and evaluates using the RGB image data. Calculate the value EV.

In S225, the CPU 110 determines whether or not the evaluation value EV is larger than the threshold value determined as the use threshold value in the evaluation condition determination process among the above-mentioned threshold values THa, THs, THm, THf, and THd. When the evaluation value EV is larger than the use threshold value (S225: YES), in S240, the CPU 110 determines the print direction of interest in a predetermined direction (in this embodiment, the outward direction). When the print direction of interest is determined, the print direction determination process is terminated.

When the evaluation value EV is equal to or less than the use threshold value (S225: NO), in S230, the CPU 110 determines whether or not the processing of all the blocks of the attention portion image is completed. If the unprocessed block remains (S230: NO), the CPU 110 returns to S215 and executes the processing of the unprocessed block. When the processing of all the blocks is completed (S230: YES), in S235, the CPU 110 determines the print direction of interest in the direction opposite to the print direction of the previous partial print (previous print direction). That is, when the immediately preceding print direction is the outward path direction, the attention print direction is determined in the return path direction, and when the immediately preceding print direction is the return path direction, the attention print direction is determined in the outward path direction. When the print direction of interest is determined, the print direction determination process is terminated.

As can be seen from the above explanation, in the printing direction determination process, if the evaluation value EV is larger than the usage threshold for at least one block BL of the attention portion printing (YES in S225), in other words, the attention portion printing is tentatively performed. When it is estimated that the color difference between the round trips and the other partial images printed in the outbound printing is conspicuous when printing in the inbound direction, the attention printing direction is determined in the outbound direction (S240). As a result, it is possible to suppress the occurrence of color unevenness due to the reciprocating color difference in the printed image OI, and it is possible to suppress the deterioration of the image quality due to the reciprocating color difference. Further, when the evaluation value EV is equal to or less than the usage threshold for all the block BLs of the attention partial print (NO in S230), in other words, even if the attention partial print is printed in the return direction, it is printed in the outward print. When it is estimated that the color difference between the reciprocating parts and the other partial images is not conspicuous, the printing direction of interest is determined in the returning direction on the condition that the immediately preceding printing direction is the outward printing direction (S240). This makes it possible to suppress a decrease in printing speed. That is, according to the printing direction determination process of this embodiment, it is possible to suppress a decrease in printing speed while suppressing a decrease in image quality due to a color difference between reciprocations. As can be seen from the above description, in this embodiment, the evaluation value EV of all the block BLs being equal to or less than the use threshold value is an evaluation condition indicating that the round-trip color difference is equal to or more than the reference for the partial image of interest. Can be said. Then, it can be said that the processing of S220 to S230 of FIG. 7 is a processing of determining whether or not the reciprocating color difference of the attention portion image is equal to or more than the reference by using the evaluation condition.

According to the first embodiment described above, the control device 100 uses the image acquisition process (S5 in FIG. 5) for acquiring the target image data corresponding to the print image OI and the target image data to perform the print image OI. For each of the plurality of partial images PI1 to PI5 (FIG. 3) included, a determination process (S220 to S230 in FIG. 7) for determining whether or not the reciprocating color difference is equal to or greater than the reference, and a plurality of partial image PIs. The target image data includes the determination process (S235 and S240 in FIG. 7) for determining each print direction of the PI5 to either the outward route direction or the return route direction based on the judgment of the determination process, and partial printing and sub-scanning. Is used to execute a printing process (S30 to S55 in FIG. 5) in which the print head 210, the main scanning unit 230, and the transport unit 240 are executed a plurality of times.

Then, the evaluation conditions used in the above determination process (S220 to S230 in FIG. 7) are determined to be different from each other depending on the type of the target image data in the evaluation condition determination process (FIG. 6). That is, when the target image data is the first type image data, the control device 100 determines that the round-trip color difference is equal to or greater than the reference when the first condition is satisfied, and the target image data is the second type. In the case of the image data of, when the second condition different from the first condition is satisfied, it is determined that the color difference between round trips is equal to or more than the reference. As a result, in the printing apparatus 200 capable of printing (bidirectional printing) using partial printing in the outward direction and the return direction, printing can be executed in an appropriate printing direction according to the target image data used for printing.

As can be seen from the above explanation, when printing is performed in both the outward and return directions, the printing speed is increased, but the image quality is likely to be deteriorated due to the color difference between the round trips. When printing is performed in one of the outward direction and the return direction, the deterioration of the image quality due to the color difference between the round trips can be suppressed, but the printing speed is reduced. According to this embodiment, printing can be executed in an appropriate printing direction according to the target image data used for printing as described above. Therefore, for example, printing can be executed in an appropriate printing direction so that an appropriate image quality and printing speed can be realized according to the target image data. Hereinafter, a more specific description will be given.

For example, in printing based on image data read from a removable memory such as a USB memory 50 or an SD card in the third pattern described above, the first pattern or the second pattern is transmitted from a terminal device (personal computer 30 or smartphone 40). It is considered that the demand for image quality is higher than that of printing based on the image data to be printed. This is because the image data read from the removable memory is image data generated by using a device such as a digital camera, image data received from another person, or relatively large image data (for example, RAW data). This is because the probability is considered to be higher than the image data transmitted from the terminal device. For this reason, in printing based on the image data read from the removable memory, the probability that the printing direction of each partial image is determined in a specific direction (outward direction in this embodiment) is based on the image data transmitted from the terminal device. It is considered preferable to make it higher than printing. In this embodiment, the threshold THm used when the target image data is the image data read from the removable memory is smaller than the thresholds THa and THd used when the target image data is the image data read from the terminal device. .. In other words, the evaluation condition used when the target image data is the image data transmitted from the terminal device indicates that the round-trip color difference is equal to or higher than the first criterion (for example, the criteria corresponding to the thresholds THa and THd). The evaluation condition, which is a condition and is used when the target image data is the image data read from the removable memory, indicates that the round-trip color difference is equal to or higher than the second criterion (for example, threshold THm) lower than the first criterion. It is a condition. As a result, when the image data read from the removable memory is used, printing can be performed with priority given to the image quality as compared with the case where the image data transmitted from the terminal device is used. Further, when the image data transmitted from the terminal device is used, printing can be performed with priority given to the printing speed as compared with the case where the image data read from the removable memory is used.

Further, the requirements for image quality and printing speed may differ depending on the application program that generates the target image data. Specifically, in printing based on the image data acquired in the first pattern, there is a possibility that an unpredictable deterioration in image quality may occur in the printed image OI when bidirectional printing is performed, which is acquired in the second pattern. It is lower than printing based on the image data to be printed. The reason for this will be explained. The image data acquired in the first pattern is generated by the driver program DP. The driver program DP is provided by the manufacturer of the multifunction device 10. Therefore, the image quality of the image data acquired in the first pattern is the image quality expected in advance. On the other hand, the image data acquired in the second pattern is generated by the print application program AP. The print application program AP is provided by a business operator different from the manufacturer of the multifunction device 10. Therefore, it is difficult to predict the image quality of the image data acquired by the second pattern. For example, depending on the color conversion process or compression process executed by the print application program AP, the image represented by the image data acquired in the second pattern may contain unexpected colors and noise. In such a case, the reciprocating color difference cannot be properly evaluated by the evaluation value EV, the deterioration of the image quality due to the reciprocating color difference becomes larger than expected, and the image quality of the printed image OI may be excessively deteriorated. .. Further, if the image quality including the image quality deterioration factor such as unexpected noise is further deteriorated due to the color difference between the round trips, the image quality of the printed image OI may be excessively deteriorated.

From the above, in printing based on the image data acquired in the second pattern, deterioration in image quality due to the color difference between round trips is suppressed as compared with printing based on the image data acquired in the first pattern. It is considered preferable to suppress excessive deterioration of the image quality of the printed image OI. In this embodiment, the threshold value THa used when the target image data is the image data acquired in the second pattern is the threshold value used when the target image data is the image data acquired in the first pattern. It is smaller than THd. In other words, the evaluation condition used when the target image data is the image data generated by executing the driver program DP is that the round-trip color difference is equal to or higher than the third criterion (for example, the criterion corresponding to the threshold THd). The evaluation condition used when the target image data is the image data generated by the print application program AP is the fourth criterion (for example, equivalent to the threshold THa) in which the color difference between round trips is lower than the third criterion. It is a condition to show that it is more than the standard of). As a result, when the image data generated by the print application program AP is used, printing can be performed with priority given to the image quality as compared with the case where the image data generated by the driver program DP is used. Further, when the image data generated by the driver program DP is used, printing can be executed with priority given to the printing speed as compared with the case where the image data generated by the print application program AP is used.

Further, the image represented by the scan data (also referred to as a scan image) includes noise and unevenness due to the variation of the signal output from the image sensor. Therefore, if the image quality of the printed image OI printed using the scan data is further deteriorated due to the color difference between the printed image OI and the image to be color-differenced between round trips, the image quality of the printed image OI may be excessively deteriorated. There is sex. For this reason, when scan data is used as in printing for copying the fifth pattern, image data generated by the driver program DP without using scan data as in the first pattern is used. It is considered preferable to suppress the deterioration of the image quality of the printed image OI excessively by suppressing the deterioration of the image quality due to the color difference between the round trips. In this embodiment, the threshold value THs used when the target image data is the scan data acquired in the fifth pattern is the threshold value used when the target image data is the image data acquired in the first pattern. It is smaller than THd. In other words, the evaluation condition used when the target image data is the image data generated by the driver program DP is a condition indicating that the round-trip color difference is equal to or greater than the seventh criterion (for example, the criterion corresponding to the threshold THd). The evaluation condition used when the target image data is scan data is a condition indicating that the round-trip color difference is equal to or higher than the eighth criterion (for example, the criterion corresponding to the threshold THs) lower than the seventh criterion. .. As a result, when scan data is used, printing can be performed with priority given to image quality as compared with the case where image data generated by the driver program DP is used. Further, when the image data generated by the driver program DP is used, printing can be performed with priority given to the printing speed as compared with the case where the scan data is used.

Furthermore, printing based on facsimile data is difficult to print again. This is because if the facsimile data is erased from the control device 100 after printing, it is necessary for the sender to resend the facsimile data in order to perform printing again. In other patterns, even if the image data is erased from the control device 100 after printing, the image data existing in the user's terminal device or the USB memory 50 or the original document in the user's hand can be easily reprinted. Is. For this reason, printing based on facsimile data preferably has high image quality. Therefore, when facsimile data is used, it is preferable that printing is performed with priority given to image quality as compared with the case where image data acquired without going through the telephone line IF190 is used. In this embodiment, the threshold value THf used when the target image data is facsimile data is smaller than the threshold values THd, THa, THs, and THm used when the target image data is other image data. In other words, the evaluation condition used when the target image data is the image data acquired without going through the telephone line IF190 is such that the round-trip color difference corresponds to the ninth criterion (for example, thresholds THd, THa, THs, THm). The evaluation condition used when the target image data is facsimile data is the tenth criterion (for example, the criterion corresponding to the threshold THf) in which the color difference between round trips is lower than the ninth criterion. It is a condition indicating that it is the above. As a result, when facsimile data is used, printing can be performed with priority given to image quality as compared with the case where image data acquired without going through the telephone line IF190 is used. Further, when the image data acquired without going through the telephone line IF190 is used, printing can be performed with priority given to the printing speed as compared with the case where the facsimile data is used.

Further, the difference in the image data acquired in this embodiment can be regarded as the difference in the data format used. For example, the image data acquired in the first pattern is dot data including each component value of CMYK. The image data (scan data) acquired in the fifth pattern is RGB image data. The image data (facsimile data) acquired in the fifth pattern is image data compressed according to a standard such as FAXG3. Therefore, in this embodiment, it can be said that the evaluation conditions are changed according to the image format of the acquired image data. Generally speaking, when the target image data is image data having the first data format, the control device 100 determines that the reciprocating color difference is equal to or greater than the reference when the first condition is satisfied. When the target image data is image data having a second data format different from the first data format, the round-trip color difference is equal to or greater than the reference when the second condition different from the first condition is satisfied. Deciding. As a result, printing can be executed in an appropriate printing direction according to the data format of the image data used for printing. The data format in this embodiment includes a format based on the color system and a compressed format. For example, the RGB image data and the CMYK dot data are image data having different data formats. Further, the compressed data according to the FAXG3 standard and the uncompressed data are image data having different data formats.

More specifically, the image data acquired in the first pattern is a color value including a plurality of component values corresponding to inks of a plurality of colors, that is, a dot containing a color value of a CMYK color system for each pixel. It is data. The image data acquired in the second to fifth patterns is image data including color values of a color system different from the CMYK color system (for example, RGB color system or monochromatic color system) for each pixel. is there. In the control device 100, the evaluation condition used when the target image data is CMYK dot data is a condition indicating that the round-trip color difference is equal to or greater than the fifth reference (for example, a reference corresponding to the threshold THd), and is a target. The evaluation condition used when the image data is color-based image data different from the CMYK dot data is the sixth criterion (for example, thresholds THs, THa, THm, THf) in which the color difference between round trips is lower than the fifth criterion. It is a condition to show that it is more than the equivalent standard). As a result, when CMYK dot data is used, printing can be performed with priority given to printing speed as compared with the case where other color-based image data is used. Further, when other color-based image data is used, printing can be performed with priority given to image quality as compared with the case where CMYK dot data is used.

Further, according to the above embodiment, the control device 100 determines whether or not the reciprocating color difference is equal to or greater than the reference value based on the comparison between the evaluation value EV and the usage threshold value (S220 and S225 in FIG. 7). Then, different threshold values are used depending on the type of target image data. For example, when the target image data is scan data, the threshold value THs is used as the usage threshold value, and when the target image data is facsimile data, the threshold value THf is used as the usage threshold value (FIG. 6). As a result, it is possible to appropriately determine whether or not the color difference between round trips is equal to or greater than the reference according to the target image data.

Further, according to the above embodiment, the control device 100 calculates the evaluation value EV using the use table (S220 in FIG. 7). Then, different usage tables are used depending on the type of target image data. For example, when the target image data is scan data, the second color evaluation table CP2 is used as the usage table, and when the target image data is data different from the scan data, the threshold THf is used as the usage threshold. (Fig. 6). For example, when the color conversion profile used for the color conversion process is different between the scan data and the data different from the scan data as in this embodiment, the evaluation value EV of each partial image is set in one color evaluation table. It may not be calculated properly. According to this embodiment, by properly using the two color evaluation tables CP1 and CP2 according to the target image data, an appropriate evaluation value EV can be calculated according to the target image data. Therefore, it is possible to appropriately determine whether or not the color difference between round trips is equal to or greater than the reference according to the target image data.

As can be seen from the above description, the wired network IF160 and the wireless network IF170 in this embodiment are examples of the first interface, and the USB IF180 is an example of the second interface. Further, the first color evaluation table CP1 is an example of the first evaluation information, and the second color evaluation table CP2 is an example of the second evaluation information. The CMYK color system is an example of the first color system, and the RGB color system is an example of the second color system. The transport unit 240 is an example of a sub-scanning unit.

B. Modified Example (1) In the above embodiment, five types of evaluation conditions different from each other are used according to the image data acquired in the first to fifth patterns. Not limited to this, two or more kinds of evaluation conditions of any number can be used. For example, the same evaluation conditions may be used for the first pattern and the second pattern in which the image data transmitted from the terminal device is used.

Further, in the above embodiment, the evaluation conditions are changed depending on whether the target image data is RGB image data or CMYK dot data. Instead of this, a plurality of types of evaluation conditions may be used properly depending on whether or not the target image data is compressed, the compression format, and the like. Further, a plurality of types of evaluation conditions may be used properly according to various characteristics related to the target image data such as the compression resolution and the number of colors of the target image data.

Further, in the above embodiment, the evaluation conditions are changed depending on whether the application program that generates the target image data is the driver program DP for the personal computer 30 or the print application program AP for the smartphone 40. Instead of this, the evaluation conditions may be changed depending on the version (update time) of the application program that generates the target image data and the provider.

(2) The specific evaluation conditions of each of the above examples are merely examples, and are not limited thereto. For example, in the above embodiment, basically, by changing the usage threshold value according to the type of image data, it is possible to control whether only one direction is likely to be determined as the print direction or both directions are likely to be determined as the print direction. doing. Instead of this, for example, a certain threshold value may be used regardless of the type of image data. In this case, for example, a plurality of types, for example, five types of color evaluation tables are prepared according to the type of image data. Then, in each of the plurality of types of color evaluation tables, the magnitude of the recorded weight Wt is different. For example, if the weight Wt recorded in the specific color evaluation table is set to a large value as a whole as compared with other color evaluation tables, the evaluation value EV calculated using the specific color evaluation table is It is relatively larger than the evaluation value EV calculated using another color evaluation table. As a result, when a specific color evaluation table is used, only one direction is more likely to be determined as the printing direction than when other color evaluation tables are used.

(3) In S240 of the print direction determination process of FIG. 7, the print direction of interest is always determined in the outward direction, but may always be determined in the return direction.

Further, in S240 of the printing direction determining process of FIG. 7, the attention printing direction is determined in the outward direction regardless of whether the immediately preceding printing direction is the outward direction or the return direction. Instead, the print direction of interest may be determined in the same direction as the immediately preceding print direction.

(4) In each of the above embodiments, paper M is used as the printing medium. Instead of this, other print media, for example, a film for OHP, a CD-ROM, or a DVD-ROM may be adopted.

(5) The arrangement position of each nozzle row of the print head 210 does not have to be the order of the nozzle rows NY, NM, NC, and NK from the upstream side in the X direction of FIG. 2B, and any other order. May be adopted. If the color difference occurs due to the different printing directions, the nozzle rows may be arranged so as to be symmetrical with respect to the printing direction.

(6) In the printing apparatus 200 of FIGS. 1 and 2, the transport unit 240 transports the paper M to move the paper M relative to the print head 210 in the transport direction. Instead of this, the paper M may be moved relative to the print head 210 in the transport direction by moving the print head 210 in the direction opposite to the transport direction with respect to the fixed paper M.

(7) In each of the above embodiments, the multifunction device 10 in which the control device 100, the printing device 200, and the reading device 300 are arranged in one housing is adopted. Instead, all or part of the control device 100, the printing device 200, and the reading device 300 may be configured in different housings and may be connected to each other via a network or a dedicated cable. .. For example, the control device 100 is a known personal computer, and the printing device 200 and the reading device 300 may be a single printer or a scanner, respectively.

(8) In each of the above embodiments, a part of the configuration realized by the hardware may be replaced with software, and conversely, a part or all of the configuration realized by the software may be replaced with the hardware. You may do so. For example, among the print control processes of FIG. 5, the color conversion process and the halftone process may be realized by, for example, a dedicated hardware circuit (for example, ASIC) that operates according to the instruction of the CPU 110.

Although the present invention has been described above based on Examples and Modifications, the above-described embodiments of the invention are for facilitating the understanding of the present invention and do not limit the present invention. The present invention can be modified and improved without departing from the spirit and claims, and the present invention includes equivalents thereof.

10 ... Complex machine, 30 ... Personal computer, 40 ... Smartphone, 60 ... Analog telephone line network, 100 ... Control device, 110 ... CPU, 111 ... Nozzle forming surface, 120 ... Non-volatile storage device, 130 ... Volatile storage device , 131 ... Buffer area, 140 ... Operation unit, 150 ... Display unit, 200 ... Printing device, 210 ... Print head, 220 ... Head drive unit, 230 ... Main scanning unit, 233 ... Carriage, 234 ... Sliding shaft, 235 ... Belt, 236 ... pulley, 240 ... transport unit, 250 ... ink supply unit, 251 ... cartridge mounting unit, 252 ... tube, 300 ... reader, 310 ... CPU, 160 ... wired network IF, 170 ... wireless network IF, 180 ... USBIF, 190 ... Telephone line IF, MC, CC, YC, KC ... Ink cartridge, NM, NC, NY, NK ... Nozzle row, PF1, PF2 ... Color conversion profile, PG ... Computer program, DP ... Driver program, AP ... Print application program, CP1, CP2 ... Color evaluation table

Claims (11)

A printing head having a first-class nozzle that ejects first-color ink and a second-class nozzle that ejects second-color ink and has a position different from that of the first-class nozzle in the main scanning direction. , The main scanning unit that executes the main scanning that moves the print head along the main scanning direction with respect to the printing medium, and the printing along the sub-scanning direction that intersects the main scanning direction with respect to the printing head. A control device for a printing device including a sub-scanning unit that executes a sub-scanning that relatively moves a medium.
Image acquisition processing to acquire target image data corresponding to the printed image,
Using the target image data, for each of the plurality of partial images included in the printed image, an image printed in the first direction along the main scanning direction and a second direction opposite to the first direction. Judgment processing to determine whether the color difference between the printed image and the image is greater than or equal to the standard, and
A determination process of determining the printing direction of each of the plurality of partial images in either the first direction or the second direction based on the determination of the determination process.
At least one of the first color ink and the second color ink from at least one of the first type nozzle and the second type nozzle of the print head while performing the main scanning in the determined printing direction. A printing process in which the print head, the main scanning unit, and the sub-scanning unit are executed a plurality of times using the target image data, that is, partial printing that prints the partial image by ejecting the ink. ,
And
In the judgment process
When the target image data is the first type image data, it is determined that the color difference is equal to or more than the reference when the first condition is satisfied.
When the target image data is the second type of image data, the control device determines that the color difference is equal to or greater than the reference when the second condition different from the first condition is satisfied. The control device according to claim 1, further
The first interface connected to the terminal device and
The second interface connected to the removable memory,
With
The first-class image data is image data transmitted from the terminal device via the first interface.
The second type of image data is image data read from the removable memory via the second interface.
The first condition is a condition indicating that the color difference is equal to or greater than the first reference.
The second condition is a condition indicating that the color difference is equal to or higher than the second reference lower than the first reference. The control device according to claim 1, further
Equipped with an interface that connects to terminal equipment
The first-class image data is image data transmitted via the interface and generated by the terminal device of the transmission source executing the first application program.
The second type of image data is image data transmitted via the interface and generated by the terminal device of the transmission source executing a second application program different from the first application program. ,
The first condition is a condition indicating that the color difference is equal to or higher than the third reference.
The second condition is a control device that indicates that the color difference is equal to or higher than the fourth reference, which is lower than the third reference. The control device according to claim 1.
The first-class image data is image data having the first data format, and is
The control device, wherein the second type of image data is image data having a second data format different from the first data format. The control device according to claim 4.
The printing apparatus executes printing using a plurality of colors of ink including the first color ink and the second color ink.
The first-class image data having the first data format is image data including the color values of the first color system including a plurality of component values corresponding to the plurality of color inks for each pixel. ,
The second type of image data having the second data format is image data including a color value of a second color system different from the first color system for each pixel.
The first condition is a condition indicating that the color difference is equal to or greater than the fifth reference.
The second condition is a control device that indicates that the color difference is equal to or higher than the sixth reference, which is lower than the fifth reference. The control device according to claim 1.
The second type of image data is scan data generated by scanning a document using an image sensor.
The first-class image data is image data generated by a specific application program without using the scan data.
The first condition is a condition indicating that the color difference is equal to or greater than the seventh reference.
The second condition is a control device that indicates that the color difference is equal to or higher than the eighth reference, which is lower than the seventh reference. The control device according to claim 1, further
Equipped with a telephone line interface that connects to a telephone line
The first-class image data is image data acquired without going through the telephone line interface.
The second type of image data is facsimile data received via the telephone line interface.
The first condition is a condition indicating that the color difference is equal to or greater than the ninth reference.
The second condition is a control device that indicates that the color difference is equal to or higher than the tenth reference, which is lower than the ninth reference. The control device according to any one of claims 1 to 7.
In the judgment process
Using the target image data and the evaluation information including the information regarding the degree of the color difference defined for each of the plurality of color values, the evaluation value regarding the degree of the color difference of the partial image is calculated.
Based on the comparison between the evaluation value and the threshold value, it is determined whether or not the color difference is equal to or greater than the standard.
The first condition is a condition determined by using the first threshold value as the threshold value.
The second condition is a condition determined by using a second threshold value different from the first threshold value as the threshold value. The control device according to any one of claims 1 to 7.
In the judgment process
Using the target image data and the evaluation information including the information regarding the degree of the color difference defined for each of the plurality of color values, the evaluation value regarding the degree of the color difference of the partial image is calculated.
Based on the comparison between the evaluation value and the threshold value, it is determined whether or not the color difference is equal to or greater than the standard.
The first condition is a condition determined based on the first evaluation value calculated by using the first evaluation information as the evaluation information and the threshold value.
The control device is a condition determined based on the second evaluation value calculated by using the second evaluation information value as the evaluation information and the threshold value. A printing head having a first-class nozzle that ejects first-color ink and a second-class nozzle that ejects second-color ink and has a position different from that of the first-class nozzle in the main scanning direction. , The main scanning unit that executes the main scanning that moves the print head along the main scanning direction with respect to the printing medium, and the printing along the sub-scanning direction that intersects the main scanning direction with respect to the printing head. A computer program for a printing apparatus comprising a sub-scanning unit that performs sub-scanning to move media relative to each other.
An image acquisition function that acquires target image data corresponding to a printed image,
Using the target image data, for each of the plurality of partial images included in the printed image, an image printed in the first direction along the main scanning direction and a second direction opposite to the first direction. A judgment function that determines whether the color difference between the printed image and the image is greater than or equal to the standard, and
A printing direction determination function that determines the printing direction of each of the plurality of partial images as either the first direction or the second direction based on the determination of the determination process.
At least one of the first color ink and the second color ink from at least one of the first type nozzle and the second type nozzle of the print head while performing the main scanning in the determined printing direction. A printing function for causing the print head, the main scanning unit, and the sub-scanning unit to execute the partial printing for printing the partial image and the sub-scanning by ejecting the target image data a plurality of times. ,
To the computer,
The judgment function
When the target image data is the first type image data, it is determined that the color difference is equal to or more than the reference when the first condition is satisfied.
When the target image data is the second type of image data, a computer program that determines that the color difference is equal to or greater than the reference when a second condition different from the first condition is satisfied. A printing head having a first-class nozzle that ejects first-color ink and a second-class nozzle that ejects second-color ink and has a position different from that of the first-class nozzle in the main scanning direction. , The main scanning unit that executes the main scanning that moves the print head along the main scanning direction with respect to the printing medium, and the printing along the sub-scanning direction that intersects the main scanning direction with respect to the printing head. A method of controlling a printing apparatus including a sub-scanning unit that executes a sub-scanning that relatively moves a medium.
An image acquisition process for acquiring target image data corresponding to a printed image,
Using the target image data, for each of the plurality of partial images included in the printed image, an image printed in the first direction along the main scanning direction and a second direction opposite to the first direction. A judgment process for determining whether or not the color difference between the printed image is equal to or greater than the standard, and
A printing direction determination step of determining the printing direction of each of the plurality of partial images in either the first direction or the second direction based on the determination of the determination process.
At least one of the first color ink and the second color ink from at least one of the first type nozzle and the second type nozzle of the print head while performing the main scanning in the determined printing direction. A printing step in which the print head, the main scanning unit, and the sub-scanning unit are executed a plurality of times by using the target image data to perform partial printing for printing the partial image and sub-scanning by ejecting. ,
With
In the determination process
When the target image data is the first type image data, it is determined that the color difference is equal to or more than the reference when the first condition is satisfied.
A method of determining that the color difference is equal to or greater than the reference when the target image data is the second type of image data and the second condition different from the first condition is satisfied.

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