JP6859650B2 - Printing equipment, printing methods, and computer programs - Google Patents

Description

The present invention relates to printing devices, printing methods, and computer programs.

Conventionally, in a serial printing apparatus having cyan (hereinafter, C), magenta (hereinafter, M), yellow (hereinafter, Y), and black (hereinafter, K) inks, a common printing area is mainly used a plurality of times. Complete by scanning. For example, in the technique described in Patent Document 1, for the color to be suppressed from bleeding, ink is ejected from a preceding nozzle in the nozzle array whose ink ejection timing is earlier than that of other nozzles.

Japanese Patent No. 5539119 Japanese Patent No. 5633110

However, in the conventional serial printing apparatus, the color development efficiency when magenta ink or cyan ink is mixed with yellow ink is not sufficiently improved, and there is a case that red or green of sufficient quality cannot be output.

The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following forms.
According to the embodiment of the present invention, a printing apparatus is provided. This printing device is a printing device that drives and prints a printing head relative to a printing medium in a main scanning direction that is the width direction of the printing medium and a sub-scanning direction that intersects the main scanning direction. A print head having a plurality of nozzle rows for ejecting at least cyan ink, magenta ink, yellow ink, and black ink, an acquisition unit for acquiring image data, and scanning of the print head in the main scanning direction. Each of the nozzle rows is provided with a dot forming portion that forms dots corresponding to the image data on the printing medium by ejecting ink to the printing medium a plurality of times in a common printing area. A leading nozzle whose scanning timing for ejecting the ink to the printing area of the above is earlier than that of other nozzles, and a trailing nozzle whose scanning timing for ejecting the ink to the common printing area is later than that of the preceding nozzle. When printing a color in the color region from red to black, the dot forming portion includes, when printing a color that mixes the black ink, the magenta ink, and the yellow ink, the magenta. The usage rate of the leading nozzle in the ink nozzle row is made higher than the usage rate of the leading nozzle in the black ink nozzle row, and the usage rate of the trailing nozzle in the yellow ink nozzle row is set to the black ink nozzle. The first process of making the usage rate of the trailing nozzles in the row higher than the usage rate of the trailing nozzles in the yellow ink nozzle row higher than the usage rate of the trailing nozzles in the magenta ink nozzle row. When printing a color that mixes the black ink, the cyan ink, and the yellow ink when printing a color in the color region from green to black, the preceding nozzle in the nozzle row of the cyan ink Is set to be higher than the usage rate of the preceding nozzle in the black ink nozzle row, and the usage rate of the trailing nozzle in the yellow ink nozzle row is set to the usage rate of the trailing nozzle in the black ink nozzle row. At least one of the second treatments in which the usage rate of the trailing nozzle in the yellow ink nozzle row is made higher than the usage rate of the trailing nozzle in the cyan ink nozzle row. Performs high color development processing. The present invention can also be realized in the following forms.

(1) According to one embodiment of the present invention, a printing apparatus is provided. This printing device is a printing device that drives and prints a print head relative to a printing medium in a main scanning direction that is the width direction of the printing medium and a sub-scanning direction that intersects the main scanning direction. A printing head having a plurality of nozzle rows for ejecting at least cyan ink, magenta ink, and yellow ink, respectively; an acquisition unit for acquiring image data; and a common printing of scanning of the printing head in the main scanning direction. The print medium is provided with a dot forming portion that forms dots corresponding to the image data on the print medium by ejecting ink onto the print medium a plurality of times in the area; each nozzle row has the common print area. Includes a leading nozzle whose scanning timing for ejecting the ink is earlier than that of other nozzles, and a trailing nozzle whose scanning timing for ejecting the ink to the common print area is later than that of the preceding nozzle. When printing at least a part of the color in the color region from red to black; the dot forming portion; the usage rate of the trailing nozzle of the yellow ink nozzle row is set to the magenta ink nozzle row. The first process of increasing the utilization rate of the trailing nozzle; when printing at least a part of the color in the color region from green to black; the use of the trailing nozzle in the nozzle row of the yellow ink. Of the second treatment in which the rate is made higher than the usage rate of the trailing nozzle in the nozzle row of the cyan ink; a high color development treatment in which at least one of the treatments is performed is performed. According to this type of printing apparatus, for example, when red or green is output using dye ink, cyan or magenta ink can be ejected mainly from the leading nozzle, and yellow ink can be ejected mainly from the trailing nozzle. , Cyan or magenta ink can occupy a part of the surface of the print medium with good color development efficiency. Therefore, the effect of expanding the color gamut is large, and it is possible to output red or green with sufficient quality.

(2) In the printing apparatus of the above embodiment, the dot forming unit performs the first process when printing a color that mixes the black ink, the magenta ink, and the yellow ink, and performs the second process. This may be performed when printing a color that mixes the black ink, the cyan ink, and the yellow ink. According to this type of printing apparatus, it is possible to improve the quality of deep red or green using black ink.

(3) In the printing apparatus of the above form, at least one of a normal mode in which printing is performed in a predetermined color gamut and a high color development mode in which printing is performed in a color gamut wider than the normal mode can be selected. The dot forming unit may perform the high color development process when the high color development mode is selected. According to this type of printing apparatus, high-quality printing can be performed when the high color development mode is selected.

(4) In the printing apparatus of the above-described embodiment, the dot-forming portion is used in the front. When the high-color development mode is selected, the dot-forming portion feeds in the sub-scanning direction as compared with the case where the normal mode is selected. You may reduce the amount. According to this type of printing apparatus, when the high color development mode is selected, printing can be performed by giving priority to quality over speed.

(5) The printing apparatus of the above embodiment includes a color conversion lookup table for converting the image data into a value corresponding to the amount of each ink; the dot forming unit has the high color development mode and the said. The color conversion look-up table having the same or different ink dot size formed on the print medium may be used in the normal mode. According to this type of printing apparatus, printing can be performed using a color conversion lookup table in which the amount of each color ink is optimized for the high color development mode, so that the quality of red and green can be effectively improved. ..

(6) In the printing apparatus of the above embodiment, in the first process, the dot forming unit ejects the magenta ink and the yellow ink from nozzles having different positions in the sub-scanning direction in the respective nozzle rows. In the second process, the cyan ink and the yellow ink may be ejected from nozzles having different positions in the sub-scanning direction in the respective nozzle rows. According to this type of printing apparatus, it is possible to print by regarding the nozzles of a plurality of colors as vertically arranged heads arranged sequentially in the sub-scanning direction in a pseudo manner, so that the ink color application order can be set in a common printing area. It can be easily controlled.

(7) In the printing apparatus of the above embodiment, the dot forming unit determines the formation of dots by comparing each threshold value of the dither mask composed of a plurality of threshold values with the pixel data constituting the image data. Yes; in the dither mask, the threshold value corresponding to the position where dots are formed by the trailing nozzle that ejects the yellow ink is the threshold value corresponding to the position where dots are formed by the preceding nozzle that ejects the yellow ink. It may be set to a value at which dots are more likely to be formed.

The present invention can be realized in various forms, for example, in the form of a printing method, a computer program, or the like. The computer program may be recorded on a computer-readable recording medium.

It is a figure which shows the schematic structure of the printing system. It is a figure which shows the schematic structure of a printer. It is the figure which looked at the arrangement of the nozzle array formed on the bottom surface of a print head from the carriage side. It is a figure which shows the design value of the utilization rate at the time of the ink duty 100% for each nozzle of the nozzle row for cyan and magenta ink. It is a figure which shows the design value of the utilization rate at the time of the ink duty 100% for each nozzle of the nozzle row for yellow ink. It is a figure which shows the design value of the usage rate at the time of ink duty 100% for each nozzle of the nozzle row for black ink. It is a figure which shows the design value of the utilization rate for each nozzle of the nozzle row for cyan and magenta ink. It is a figure which shows the design value of the utilization rate at the time of the ink duty 100% for each nozzle of the nozzle row for yellow ink. It is a figure which shows a mode that a certain nozzle row is sub-scanned for every pass. It is a figure which shows an example of the overlap nozzle map. It is a figure which shows an example of the overlap nozzle map. It is a figure which shows an example of the overlap nozzle map. It is a flowchart of a print process executed by a computer. It is a figure which showed the maximum saturation of red when it was output with cyan, magenta, yellow, and black ink in a normal process and a high color development process. It is a figure which shows a mode that a certain nozzle row is sub-scanned for every pass. It is a figure which shows the design value of the utilization rate for each nozzle of the nozzle row for cyan and magenta ink. It is a figure which shows the design value of the utilization rate for each nozzle of the nozzle row for yellow ink. It is a figure which shows an example of the overlap nozzle map. It is a figure which shows an example of the overlap nozzle map. It is the figure which looked at the arrangement of the nozzle array formed on the bottom surface of a print head from the carriage side. It is a figure which shows the design value of the nozzle use rate at the time of ink duty 100% for each nozzle of each color ink. It is the figure which looked at the arrangement of the nozzle array formed on the bottom surface of a print head from the carriage side. It is the figure which looked at the arrangement of the nozzle array formed on the bottom surface of a print head from the carriage side. It is a figure which shows the schematic structure of the printing system in 4th Embodiment. It is a figure which shows a mode that a certain nozzle row is sub-scanned for every pass. It is a figure which shows the design value of the utilization rate at the time of the ink duty 100% for each nozzle of the nozzle row for cyan and magenta ink. It is a figure which shows the design value of the utilization rate at the time of the ink duty 100% for each nozzle of the nozzle row for yellow ink.

A-1. First Embodiment:
FIG. 1 is a diagram showing a schematic configuration of a printing system 10 as an embodiment of the present invention. As shown in the figure, the printing system 10 of the present embodiment includes a computer 100 and a printer 200 that actually prints an image under the control of the computer 100. The printing system 10 functions as a printing device in a broad sense as a whole.

A predetermined operating system is installed in the computer 100 shown in FIG. 1, and the application program 20 is operating under this operating system. The video driver 22 and the printer driver 24 are incorporated in the operating system. The application program 20 inputs image data IMG from the digital camera 120, for example, through a peripheral device interface or the like. Then, the application program 20 displays the image represented by the image data IMG on the display 114 via the video driver 22. Further, the application program 20 outputs the image data IMG to the printer 200 via the printer driver 24. The image data IMG input by the application program 20 from the digital camera 120 is color data composed of three color components of red (R), green (G), and blue (B).

The printer driver 24 that corresponds to the "dot forming unit" of the present application and realizes the "dot forming function" includes an image acquisition module 40, a color conversion module 42, a halftone module 44, and a print data output module 46. There is. The image acquisition module 40, which corresponds to the “acquisition unit” of the present application and realizes the “acquisition function”, acquires the image data to be printed from the application program 20.

The color conversion module 42 refers to the color conversion lookup table LUT prepared in advance, and refers to the color components R, G, and B of the image data that can be expressed by the printer 200 (cyan (C), magenta (M)). , Yellow (Y), Black (K)) are converted to values corresponding to the amount of each ink.

The halftone module 44 performs halftone processing that represents the image data after color conversion by the distribution of dots. The halftone module 44 performs halftone processing using a dither mask DM prepared in advance.

The print data output module 46 rearranges the data representing the arrangement of dots of each color obtained by the halftone processing according to the order of dot formation by the print head 241 of the printer 200, and outputs the data as print data to the printer 200.

In the present embodiment, the usage rate of each nozzle provided on the print head 241 described later is set according to the ink color. More specifically, of the multiple main scanning passes that scan the common print area, the cyan ink and magenta ink are mainly printed on the leading pass, and the yellow ink is mainly printed on the trailing pass, which is later than the leading pass. Set the usage rate of each nozzle so that it hits with. In this way, the printing system 10 prints mainly on the leading pass so that the cyan ink and magenta ink occupy the portion of the surface of the printing medium having good color development efficiency, and prints the yellow ink on the trailing pass, thereby printing the color gamut of the printing result. Is expanding. The principle of printing yellow ink later will be described in detail later.

FIG. 2 is a diagram showing a schematic configuration of the printer 200. The printer 200 is a so-called serial printer, and has a transport mechanism for transporting the print medium P in the paper feed direction by the paper feed motor 235 and a carriage 240 in the axial direction of the platen 236 by the carriage motor 230, that is, the width of the print medium P. A main scanning mechanism that conveys the paper a plurality of times in the main scanning direction, which is a direction, a mechanism that drives a print head 241 mounted on the carriage 240 to eject ink and form dots, and these paper feed motors 235 and carriage motor 230. , The control circuit 260 that controls the exchange of signals with the print head 241 and the operation panel 256. As the print medium P, for example, a medium having an ink absorbing layer (coat layer) made of fine particles such as silica having fine voids on the surface can be used.

The main scanning mechanism that reciprocates the carriage 240 in the axial direction of the platen 236 is endless between the sliding shaft 233, which is erected in parallel with the axis of the platen 236 and holds the carriage 240 slidably, and the carriage motor 230. It is composed of a pulley 232 on which the drive belt 231 is stretched, a position detection sensor 234 that detects the origin position of the carriage 240, and the like.

A plurality of ink cartridges 243 containing cyan ink (C), magenta ink (M), yellow ink (Y), and black ink (K) are mounted on the carriage 240. In this embodiment, the color material of the ink is a dye. The print head 241 provided at the bottom of the carriage 240 is formed with nozzle rows 244 to 247 for ejecting ink for each color of ink.

FIG. 3 is a view of the arrangement of the nozzle rows formed on the bottom surface of the print head 241 as viewed from the carriage 240 side. As shown in the figure, the print head 241 includes nozzle rows 244 to 247 formed by arranging a plurality of nozzles in the sub-scanning direction intersecting the main scanning direction. In this embodiment, each nozzle row is composed of 14 nozzles. Ink is supplied from the ink cartridge 243 mounted on the carriage 240 to these nozzle rows 244 to 247, and cyan ink (C), magenta ink (M), yellow ink (Y), and black ink (K) are discharged, respectively. It is possible. Hereinafter, the number of the nozzle on the front end side will be referred to as “13” and the number of the nozzle on the rear end side will be referred to as “0” in the sub-scanning direction. As shown in FIG. 3, in the present embodiment, the nozzle rows corresponding to each ink color are configured by arranging the nozzles in a row in the sub-scanning direction, but the arrangement of the nozzles in each nozzle row is particularly important. It is not limited. For example, the nozzles may be arranged in a plurality of rows for one ink color, or the nozzles may be arranged in a staggered pattern.

As shown in FIG. 2, the control circuit 260 included in the printer 200 is configured by connecting a CPU 102, a ROM, a RAM, a PIF (peripheral device interface), and the like to each other by a bus. When the control circuit 260 receives the print data output from the computer 100 via the PIF, the control circuit 260 drives the carriage motor 230 to reciprocate the print head 241 with respect to the print medium P a plurality of times in the main scanning direction. Further, by driving the paper feed motor 235, the print medium P is moved in the paper feed direction. The control circuit 260 prints by driving the nozzles at appropriate timings based on the print data in accordance with the reciprocating movement of the carriage 240 (main scan) and the paper feed movement of the print medium (secondary scan). Ink dots of the appropriate color are formed at appropriate positions on the medium P. By doing so, the printer 200 can print a color image on the print medium P. In this embodiment, the print medium is conveyed in the paper feed direction, but the position of the print medium may be fixed and the carriage 240 may be conveyed in the direction opposite to the sub-scanning direction. That is, the print head 241 may be driven relative to the print medium P in the main scanning direction and the sub-scanning direction, respectively.

In the present embodiment, as a mode of drive control of the print head 241, the number of nozzles per color is "14", the nozzle pitch is "2", the paper feed amount is "7", and the print head 241 is moved forward. Bidirectional printing that ejects ink both at the time of recovery and at the time of recovery is performed. In the present embodiment, since the nozzle pitch is set to "2", dots are formed every other line in one main scan of the print head 241. Focusing on the area of 7 lines corresponding to the amount of paper feed at one time, in the first main scanning pass, which is the preceding pass, every other line is provided by the four tip side nozzles of nozzle numbers 10 to 13. Dots are formed in the second main scanning pass, dots are formed in the line between the three nozzles of nozzle numbers 7 to 9, and in the third main scanning pass, nozzle numbers 3 to 6 are 4 The book nozzle duplicates scanning on the same line as the first main scanning pass, and in the fourth main scanning pass, which is the trailing pass, the three rear end side nozzles with nozzle numbers 0 to 2 are used. Duplicate scanning is performed on the same line as the first main scanning path. As described above, in the present embodiment, the common print area is completed by four main scanning passes.

As described above, the printing system 10 of the present embodiment has a function of expanding the color gamut of the printing result. In order to realize such a function, the printing system 10 controls to increase the usage rate of the nozzles on the rear end side in the sub-scanning direction as compared with the nozzles on the front end side in the nozzle array for ejecting yellow ink. Do. Hereinafter, the nozzle on the rear end side that increases the usage rate is referred to as a "following nozzle", and the nozzle on the front end side that relatively lowers the usage rate is referred to as a "leading nozzle". Specifically, when the common print area is completed by a plurality of main scanning passes, the nozzle in charge of the leading pass is the leading nozzle, and the nozzle in charge of the trailing pass is the trailing nozzle. However, when the number of scans is odd, the nozzle in charge of the central path may not belong to either. Further, since the leading nozzle is in charge of the main scanning path earlier than other nozzles including the trailing nozzle, the timing of ejecting ink is early. That is, the leading nozzle has a scanning timing for ejecting ink to the common printing area earlier than the trailing nozzle. In the present embodiment, the number of trailing nozzles for increasing the usage rate is seven. As shown in FIG. 3, in the present embodiment, the trailing nozzles are nozzles Nos. 0 to 6, and the leading nozzles are nozzles Nos. 7 to 13.

FIG. 4 is a diagram showing a design value of a usage rate when the ink duty of each nozzle of the nozzle row for cyan and magenta ink in the present embodiment is 100%, and FIG. 5 is a diagram showing a nozzle row for yellow ink in the present embodiment. It is a figure which shows the design value of the usage rate at the time of ink duty 100% for each nozzle. Further, FIG. 6 is a diagram showing a design value of a usage rate when the ink duty of each nozzle of the nozzle row for black ink in this embodiment is 100%. The ink duty is a ratio of pixels in which dots are turned on in a predetermined print area.

FIG. 4 shows an example in which the usage rate of the leading nozzle is increased, FIG. 5 shows an example in which the usage rate of the trailing nozzle is increased, and FIG. 6 shows an example in which the usage rates of the leading nozzle and the trailing nozzle are equal. When the ink duty is less than 100%, unless special consideration is given to the halftone side, the value is obtained by multiplying the usage rate when the ink duty is 100% by the duty value at that time (100% is set to 1). However, these are expected values at the time of design, and if the ink duty is less than 100%, there will be variations when viewed in units of nozzle numbers. In this figure, the vertical axis indicates the nozzle usage rate, and the horizontal axis indicates the nozzle number. The nozzle usage rate means the probability that a dot is formed by a certain nozzle. Cyan and magenta inks are ejected using nozzle numbers 7 to 13 which are leading nozzles (see FIG. 4), and yellow ink is ejected using nozzle numbers 0 to 6 which are trailing nozzles (see FIG. 5). If the yellow ink is ejected as shown in FIG. 5, the yellow ink can be ejected mainly by the trailing nozzle.

FIGS. 4 and 5 show 0 to 2, 3 to 6, 7 to 9, and 10 used in the same pass in four main scanning passes for completing a common print area. The nozzle usage rate is the same within each group of Nozzle No. 13. On the other hand, as shown in FIGS. 6, 7 and 8, the design may be such that the nozzle usage rate changes according to the nozzle number even in the nozzle group belonging to the same path. FIG. 7 is a diagram showing design values of usage rates of cyan and magenta ink nozzle rows for each nozzle, and FIG. 8 is a design of usage rates of yellow ink nozzle rows for each nozzle when the ink duty is 100%. It is a figure which shows the value. By ejecting ink as shown in FIGS. 6, 7 and 8, the usage rate of the end portion of the nozzle row can be reduced, and further, the occurrence of banding in which the joint is recognized as a streak in the cycle of the paper feed amount is suppressed. It is effective for.

FIG. 9 is a diagram showing a state in which a certain nozzle row is sub-scanned for each pass. FIG. 9 shows how the nozzle row moves relative to the print medium. FIG. 9 shows how the nozzle row is moving, but when the print medium is moved instead of the nozzle row, the moving direction is opposite. In the present embodiment, a nozzle array composed of 14 nozzles (Nos. 0 to 13) is sub-scanned (paper-fed) by 7 pixels each time a main scan is performed. Then, in the present embodiment, the common print area CA is filled with dots by four main scans and three sub scans to complete the process. The common print area CA in the present embodiment is an area having a width of 7 dots in the sub-scanning direction. In the present embodiment, the same combination of nozzle numbers appears repeatedly in a cycle of 7 dots in the sub-scanning direction width that matches the paper feed amount.

In order to complete the common print area CA by the drive control of the print head 241 as described above, in the present embodiment, the nozzle numbers 10 to 13 are set in the first pass, the nozzle numbers 7 to 9 are set in the second pass, and the nozzles are used. Numbers 3 to 6 are used in the third pass, and nozzle numbers 0 to 2 are used in the fourth pass. Then, the nozzle numbers 10 to 13 and the nozzle numbers 3 to 6 are the same in the first pass and the third pass, and the nozzle numbers 7 to 9 and the nozzle numbers 0 to 2 are the same sub-scanning in the second pass and the fourth pass. Since the directional pixel position is scanned, the same pixel position can be printed in either pass. That is, since two nozzles having 7 different nozzle numbers scan the same sub-scanning direction position in duplicate, the solid lines in FIGS. 4, 5, 6, 7, and 8 show the nozzle numbers N (N is 0 to 6). The sum of the nozzle usage rate of the nozzles of nozzle number N + 7 and nozzle number N + 7 is 100%. Therefore, for example, nozzle number 10 is 50% in the first pass and nozzle number 3 is 50% in the fourth pass. The expected value of each utilization rate can be controlled so as to form. In the present embodiment, the usage rate of each of the plurality of nozzles included in the print head 241 is set by the overlapping nozzle map described below.

FIG. 10 is a diagram showing an example of the overlapping nozzle map NM1 that realizes the characteristics shown in FIG. The overlapping nozzle map NM1 corresponds to the common print area CA of FIG. 9, has a vertical size of 7 along the sub-scanning direction, which is the same as the print area CA, and a horizontal size of 8 along the main scanning direction. Each grid shown in FIG. 10 represents one dot, and the numbers in the grid indicate the numbers of the nozzles that form the dots. That is, the overlapping nozzle map shows for each pixel position in the main scanning direction which of the nozzles having the same sub-scanning direction position and the overlapping relationship, such as the 0th nozzle and the 7th nozzle, is used to form the dots. Therefore, the dots formed on the print medium have a unique correspondence between the formation position and the number of the nozzle forming the dots. By repeatedly applying this overlapping nozzle map on the print medium, it is possible to specify which nozzle forms the dot at which pixel position.

In FIG. 10, the Nth nozzle (N is an integer from 0 to 6) and the N + 7th nozzle, which are in an overlapping relationship, are used at a ratio of (N + 1) / 8 and (7-N) / 8, respectively, and the halftone side is used. Unless special consideration is given, the expected value of the ratio of the number of pixels in which dots are turned on by each nozzle is this ratio. In the overlapping nozzle map of FIG. 10, the usage rate is lowered toward the nozzles located at the end of the nozzle row, thereby reducing the banding in which the boundary of the sub-scanning feed is visually recognized as a streak.

FIG. 11 is a diagram showing an example of the overlapping nozzle map NM2 that realizes the characteristic that the usage rate of the preceding nozzles 7 to 13 is high, which is shown in FIG. FIG. 11 is an example of a nozzle map in which the main scanning direction repeats a cycle of 8 pixels. Nozzles 0 to 6 have a ratio of 2 pixels to 8 pixels at 25%, and nozzles 7 to 13 have a ratio of 6 pixels to 8 pixels. Since the allocation rate is 75%, the nozzles are probabilistically used at this rate, and a halftone in which the usage rate in FIG. 4 is an expected value can be realized. The allocation rate is a value indicating the ratio of nozzles having an overlapping relationship in the overlapping nozzle map, and is consistent with the nozzle usage rate when the ink duty is 100%. Further, FIG. 12 is also a diagram showing an example of the overlapping nozzle map NM3 that realizes the characteristic that the usage rate of the preceding nozzles 0 to 6 is high, which is also shown in FIG. The size of the overlapping nozzle map may be larger or smaller than the size shown in FIGS. 10 to 12 both vertically and horizontally. The larger the size in the main scanning direction in the lateral direction, the finer the usage rate of each nozzle can be set and the longer the repetition period can be increased. For example, by setting the horizontal size to 16 pixels or more, it is possible to set different usage rates for each nozzle with a resolution of 1/16 or more as shown in FIGS. 7 and 8. It is desirable to create the overlapping nozzle map so that the pixel positions formed in one main scanning pass are arranged in the same group so that they are evenly distributed evenly when viewed in group units. The arrangement itself may be regular or irregular. Further, the size in the sub-scanning direction in the vertical direction is not limited to the size shown in FIGS. 10 to 12 as long as it is an integral multiple of 7, which is the paper feed amount. The minimum unit of the vertical size is the cycle in which the combination of corresponding nozzle numbers repeats the same. In the case of this embodiment, it is 7, but for example, when the paper feed amount is not constant and the feeds of 7 and 11 are alternately performed, the repetition period is 18 which is the sum of 7 and 11. The usage rate shown by the broken line in FIG. 7 will be described in the second embodiment.

The printer driver 24 uses the magenta ink to be yellow ink and black ink, not only when printing at least a part of the colors in the color region from red to black, that is, when mixing magenta ink and yellow ink. When mixing the colors, the first process is performed in which the leading nozzle of the magenta ink nozzle row has a higher usage rate than the trailing nozzle, and the trailing nozzle of the yellow ink nozzle row has a higher usage rate than the leading nozzle. That is, in this first treatment, the usage rate of the trailing nozzles in the nozzle row of yellow ink is made higher than the usage rate of the trailing nozzles in the nozzle row of magenta ink. Further, the printer driver 24 not only prints at least a part of the colors in the color region from green to black, that is, when mixing the cyan ink and the yellow ink, but also applies the yellow ink to the cyan ink. When mixing with black ink, a second process is performed in which the leading nozzle of the cyan ink nozzle row has a higher usage rate than the trailing nozzle, and the trailing nozzle of the yellow ink nozzle row has a higher usage rate than the leading nozzle. Do. That is, in this second process, the usage rate of the trailing nozzles in the yellow ink nozzle row is made higher than the usage rate of the trailing nozzles in the cyan ink nozzle row. In the present embodiment, performing at least one of such a first process and a second process is referred to as a high color development process. In the present embodiment, in the high color development process, both the first process and the second process are performed. Hereinafter, the printing process in which the high color development processing is performed will be described in detail.

FIG. 13 is a flowchart of a printing process executed by the computer 100 of the present embodiment. This printing process is performed by the CPU 102 as hardware executing a program prepared as a printer driver 24. The program may be stored in the memory of the computer 100, or may be recorded in various recording media readable by the computer 100. In this printing process, the computer 100 first acquires the RGB format image data IMG from the application program 20 by using the image acquisition module 40 (step S100). The step S100 is also referred to as a “acquisition step”.

When the image data is acquired, the computer 100 uses the color conversion module 42 to perform a color conversion process of converting the RGB format image data acquired in step S100 into CMYK format image data corresponding to the output ink color of the printer. This is performed to determine the pixel data (ink duty) of each ink color (step S200).

When the image data in CMYK format is obtained, the computer 100 uses the halftone module 44 to use the dither mask DM for each of the cyan (C), magenta (M), yellow (Y), and black (K) colors. Halftone processing is performed (step S300). In the present embodiment, the halftone module 44 performs the halftone processing by the systematic dither method using the dither mask DM, but the halftone processing may be performed by another method such as the error diffusion method.

When the halftone processing is completed, the computer 100 outputs each image data of the halftone processed C, M, Y, and K to the printer 200 as print data by using the print data output module 46 (step S400). ). At this time, the computer 100 refers to the overlapping nozzle maps NM2 and NM3, and includes data for designating which nozzle is used to form dots in each pixel for each ink color in the print data. By the process of step S400, the above-mentioned first process and second process are realized. The step S400 is also referred to as a "dot forming step".

Upon receiving this print data, the printer 200 drives the print head 241 with the nozzle pitch set to "2" and the paper feed amount set to "7" as shown in FIG. Bidirectional printing is performed by ejecting ink of each color from the nozzle specified in the print data at both times of recovery.

FIG. 14 is a diagram showing the maximum saturation in the red gradation that changes in the order of black, red, and white when printed with cyan, magenta, yellow, and black ink in the normal processing and the high color development processing. The normal process is different from the high color development process in which the yellow ink is ejected later, and the yellow ink is also a process in which the ink is ejected at the same scanning timing as the magenta or cyan ink. In this figure, the vertical axis on the left side shows the c * value of the maximum saturation of red, and the vertical axis on the right side shows the difference value obtained by subtracting the c * value during normal processing from the c * value during high color development processing. , The horizontal axis shows the L * value corresponding to the brightness. L * value = 10 is black, L * value = 90 is a color close to white, and L * value = 55 is the most saturated red color.

As the red color in FIG. 14, a color having a hue angle of 45 degrees in the L * a * b * color system according to the CIE standard, that is, a * = b * (more accurately, a red color rather than yellow) is selected, and the brightness is selected. In the case where the L * value corresponding to is 17 levels in 5 increments from 10 to 90, the color having the maximum saturation was investigated during the normal treatment and the high color development treatment. The color with the maximum saturation is a value corresponding to the saturation under the condition of a * = b * from the result of investigating the output result of the combination of the ink amounts of the four colors C, M, Y, and K. A color having the maximum c * = √ (a * ² + b * ² ) was searched for and obtained for each L * value. The output color is measured only for the combination color when the Duty (dot ON rate) of each ink color is changed at intervals of about 5%, and the output color for an arbitrary amount of ink is calculated by linear interpolation calculation. I asked.

From FIG. 14, it is found that in the high color development processing, there is a high saturation expansion effect of 4 to 6 in terms of Δc * value on the dark side of red where the L * value is in the range of 15 to 50 as compared with the normal processing. I understand. The dark area side can be said to be an area where cyan or black ink (mainly black ink) is mixed in order to reduce the brightness in addition to magenta ink and yellow ink. In order to achieve high saturation in dark areas, it is necessary to add cyan ink and black ink without reducing yellow ink and magenta ink as much as possible, and the total amount of ink tends to increase more than in bright areas. It is said that the difference in Δc * value is perceptually recognizable by a difference of 3 or more, and it is clear that an improvement in which the expansion of the color gamut can be visually recognized has been realized.

The above tendency varies depending on the ink set and media used, and there may be combinations with particularly large effects, but the tendency was confirmed in most combinations. In addition, in the green gradation that changes in the order of black, green, and white, there is a similar tendency for the dark part of green, although there is a difference in degree. The dark part of green is a region where cyan ink and yellow ink for developing green are mixed with magenta or black ink (mainly black ink) for lowering the brightness.

According to the printing process described above, when printing at least a part of the colors in the color region from red to black, if the same printing position on the printing medium is viewed, the yellow ink is the magenta ink. Is discharged relatively later than. Further, when printing at least a part of the colors in the color region from green to black, the yellow ink is ejected relatively later than the cyan ink when the same printing position on the printing medium is viewed. To. Therefore, after the magenta ink and the cyan ink occupy the portion of the surface of the print medium having good color development efficiency, the yellow ink is struck and permeates into the print medium. Therefore, the effect of expanding the color gamut is large, and it is possible to output red or green with sufficient quality. Further, this effect becomes particularly remarkable in a high-saturation dark area where the total amount of ink increases and the margin of ink absorption amount of the medium becomes small.

In the present embodiment, the usage rates of the leading nozzle and the trailing nozzle are set to be equal for the black ink, but the black ink may be set to increase the usage rate of the leading nozzle as in the case of cyan and magenta ink. Further, as with the yellow ink, the setting may be set so that the usage rate of the trailing nozzle is increased.

A-2. Modification example of the first embodiment:
As a mode of drive control of the print head 241, the nozzle pitch is set to "2", the paper feed amount is set to "9", and bidirectional printing is performed in which ink is ejected both when the print head moves forward and backward. May be good. FIG. 15 is a diagram showing a state in which a certain nozzle row is sub-scanned for each pass. FIG. 15 shows how the nozzle row moves relative to the print medium. In this modification, a nozzle array composed of 14 nozzles (Nos. 0 to 13) is sub-scanned (paper-fed) by 9 pixels each time the main scan is performed. Then, the common print area CA is filled with dots by three main scans and two sub scans to complete the process. In this modification, the common print area CA is an area having a width of 9 pixels in the sub-scanning direction. This embodiment shows an example in which a common print area CA is completed with an odd number of main scans.

In order to complete the common print area CA by the drive control of the print head 241 as described above, the nozzle numbers 9 to 13 are set in the first pass, the nozzle numbers 5 to 8 are set in the second pass, and the nozzle numbers 0 to 4 are set. Use on the 3rd pass. Then, since the nozzle numbers 9 to 13 and the nozzle numbers 0 to 4 scan the same pixel position in the first pass and the third pass, the same pixel position can be printed in either pass. Therefore, for example, the usage rates of nozzle numbers 9 to 13 can be controlled to form dots at a ratio of 50% in the first pass, and nozzle numbers 0 to 4 can be controlled to form dots at a ratio of 50% in the third pass.

FIG. 16 is a diagram showing a design value of the usage rate of the cyan and magenta ink nozzle rows for each nozzle in this modification, and FIG. 17 is a diagram showing the usage rate of the yellow ink nozzle row for each nozzle in this modification. It is a figure which shows the design value. In FIGS. 4, 5 and 6, only the usage rate when the ink duty is 100% is displayed, but in FIGS. 16 and 17, the nozzle usage rates when the ink duty is 100%, 40% and 16%, respectively, are displayed. It is shown. The nozzle usage rate at 100% multiplied by 0.4 is the nozzle usage rate at 40%, and the nozzle usage rate multiplied by 0.16 is the nozzle usage rate at 16%. As shown in FIG. 16, at each ink duty, the usage rate of nozzle numbers 9 to 13 which are leading nozzles is higher than the usage rate of nozzle numbers 0 to 4 which are trailing nozzles. Further, as shown in FIG. 17, in each ink duty, the usage rate of nozzle numbers 9 to 13 which are leading nozzles is low, and the usage rate of nozzle numbers 0 to 4 which are trailing nozzles is the use of leading nozzles. Higher than the rate.

When the cyan and magenta inks are ejected as shown in FIG. 16, the nozzle numbers 5 to 13 including the preceding nozzle are mainly used to eject the ink, and when the yellow ink is ejected as shown in FIG. 17, the ink is ejected. Nozzles 0 to 8 including the trailing nozzle are mainly used to eject ink. When the ink duty is 40% or 100%, a nozzle near the center of the nozzle row is mainly used. Therefore, the occurrence of banding can be suppressed. In this modification, the usage rate of each of the plurality of nozzles included in the print head 241 is set by the overlapping nozzle map described below.

FIG. 18 is a diagram showing an example of the overlapping nozzle map NM4 that realizes the ink usage rate shown in FIG. The overlapping nozzle map NM4 has a horizontal size of 4 along the main scanning direction and a vertical size of 27 along the sub-scanning direction. Each grid shown in FIG. 18 represents one dot, and the numbers in the grid indicate the numbers of the nozzles that form the dots. That is, the dots formed on the print medium have a unique correspondence between the formation position and the number of the nozzle forming the dots. By repeatedly applying this overlapping nozzle map on the print medium, it is possible to specify which nozzle forms the dot at which pixel position. FIG. 18 is an example of a nozzle map in which the main scanning direction repeats a cycle of 4 pixels. Nozzles 0 to 4 have an allocation rate of 25%, nozzles 5 to 8 have an allocation rate of 100%, and nozzles 9 to 13 have an allocation rate of 75%. Probabilistically, the nozzles are used at such a ratio, and a halftone in which the usage rate in FIG. 16 is an expected value can be realized. Further, FIG. 19 is a diagram showing an example of the overlapping nozzle map NM5 that realizes the ink usage rate shown in FIG.

When the number of passes is odd as in the drive control of FIG. 15 described above, it is assumed that the dots generated in the middle pass do not belong to the leading pass or the trailing pass, and the usage rate of the leading nozzle and the trailing nozzle May be excluded from the calculation of the usage rate of.

B. Second embodiment:
In the first embodiment described above, the printing process is performed using the dither mask DM and the overlapping nozzle map, but since the dither mask and the overlapping nozzle map are created independently without being related to each other, each nozzle number is used. The expected value of the nozzle usage rate of is determined only by the overlapping nozzle map. That is, although the usage rate for each nozzle when the ink duty is less than 100% actually varies, the expected value is the nozzle allocation rate, that is, the usage rate when the duty is 100% and the duty value (100) at that time. It is the value multiplied by (% is 1). On the other hand, in the second embodiment, a dither mask in which the dither mask DM is associated with the overlapping nozzle map shown in FIG. 11 is used. This makes it possible to make the nozzle usage rate when the ink duty is less than 100% a characteristic different from the shape determined by the allocation rate. That is, characteristics different from those obtained by multiplying the usage rate of 100% (shown by the solid line) by 0.625, such as the usage rate at 62.5% (shown by the broken line) in FIG. 7, specifically, the preceding It is possible to realize the characteristic that the usage rate of the nozzle is higher and further enhance the effect of the present invention.

In the second embodiment, the size of the dither mask DM is set to an integral multiple of the overlapping nozzle map size in both the vertical and horizontal directions so that the nozzle number corresponding to the position on the dither mask DM is uniquely determined. With reference to the overlapping nozzle map NM2 shown in FIG. 11, the dither mask DM is generated in advance so that the ratio at which the small threshold value at which dots are likely to be formed is arranged at the position of the nozzle number of the trailing nozzle is increased. A method for setting such a dither mask threshold value is described in, for example, Patent Document 2. If such a nozzle DM is generated in advance and the nozzle DM is applied to cyan and magenta inks, when the ink duty of cyan and magenta is close to 100%, as shown by the solid line in FIG. , The usage rate of the end of the nozzle row is low, and the usage rate of the leading nozzles (nozzle numbers 7 to 13) is higher than that of the trailing nozzles (nozzle numbers 0 to 6), so banding suppression and color gamut expansion effect The nozzle usage rate is set in a balanced manner. Further, when the ink duty of cyan and magenta ink is 62.5% or less, which is an intermediate value, as shown by the broken line in FIG. 7, it becomes more difficult for the trailing nozzle to form dots. The setting emphasizes the effect of expanding the color gamut of red and green. For example, when you want to output red by mixing yellow ink and magenta ink, if you eject both of them close to 100%, the media will exceed the limit of ink absorption. In most cases, yellow ink and magenta ink are suppressed to a discharge rate of 60% or less, and such a setting is very effective for the color gamut expansion effect.

Regarding the ink duty values not shown in FIG. 7, for example, the ink duty values are 100%, 62.5%, and 0% for each nozzle number (the nozzle usage rate when the ink duty value is 0% is 0% for all nozzles). From the value of, the value obtained by linear interpolation may be used as the design value at the time of creating the dither mask. Further, if the method for creating the dither mask in the present embodiment is applied, the leading nozzle and the trailing nozzle are used in the same ratio when the ink duty value is 100%, but the trailing nozzle is used when the ink duty value is 60% or less. Alternatively, it is possible to create a combination of overlapping nozzle maps and dither masks in which the ratio of preceding nozzles increases.

C-1. Third Embodiment:
In the third embodiment, at least two nozzle rows among the plurality of ink color nozzle rows arranged in the main scanning direction are treated as pseudo-arranged nozzle rows in the sub-scanning direction. FIG. 20 is a view of the arrangement of the nozzle rows formed on the bottom surface of the print head 241 in the present embodiment as viewed from the carriage 240 side. In this embodiment, each nozzle row is composed of 21 nozzles. Hereinafter, the number of the nozzle on the front end side will be set to "20" and the number of the nozzle on the rear end side will be set to "0" in the sub-scanning direction.

In the present embodiment, the control circuit 260 does not use the nozzles shown in white in FIG. 20, but uses nozzles filled with black surrounded by a frame. Specifically, when ejecting magenta and cyan ink, only nozzle numbers 14 to 20 which are the leading nozzles are ejected, when ejecting black ink, only nozzle numbers 7 to 13 in the center are ejected, and when ejecting yellow ink, only nozzle numbers 7 to 13 are ejected. , Only nozzle numbers 0 to 6, which are the trailing side nozzles, are used. By doing so, the heads of seven nozzles for each color can be arranged in three rows in the sub-scanning direction in the order of (1) magenta and cyan ink, (2) black ink, and (3) yellow ink. The print head 241 can be handled in the same manner as using a head in which the ink trains are arranged in the main scanning direction.

FIG. 21 is a diagram showing a design value of the nozzle usage rate when the ink duty of each nozzle of each color ink in this embodiment is 100%. In this figure, the vertical axis indicates the nozzle usage rate, and the horizontal axis indicates the nozzle number. As described above, magenta and cyan inks use only nozzle numbers 14 to 20, black ink uses only nozzle numbers 7 to 13, and yellow ink uses only nozzle numbers 0 to 6.

According to the present embodiment, by limiting the nozzles used by the control circuit 260 in the nozzle array for each ink color, the nozzle array of a plurality of colors arranged in the main scanning direction is pseudo-arranged in the sub-scanning direction. It can be printed as if it were a row of nozzles. Therefore, the order of applying the ink colors can be easily controlled in the common print area. The ink application order is cyan and magenta ink first, then black ink, and finally yellow ink. Therefore, cyan and magenta ink occupy a portion of the surface of the print medium having good color development efficiency, then black ink is struck without being mixed with yellow ink, and finally yellow ink is struck. Therefore, the effect of expanding the color gamut is large, and it is possible to output red or green with sufficient quality. Further, by preceding the black ink with the yellow ink, the black ink can be stopped on the surface layer more than the yellow ink, so that the brightness can be lowered while suppressing the decrease in saturation with a small amount of black ink.

C-2. Modification example of the third embodiment:
In FIG. 20, there is no overlap of nozzles in the main scanning direction between the yellow ink and the black ink, and the black ink and the magenta ink and the cyan ink, but some nozzles can be overlapped. For example, FIG. 22 shows an example in which only three nozzles have overlap between yellow ink and black ink, and between black ink and magenta ink and cyan ink. Even if some nozzles are overlapped in this way, a sufficient color gamut expansion effect can be obtained. Further, since the number of nozzles per color can be increased to 9, the paper feed amount can be increased to 9 to increase the printing speed.

Further, in the nozzle configuration of FIG. 22, the paper feed amount of 7 may be left as it is, and the two nozzles of the increased number of nozzles used for each color ink may be configured to scan the same raster in duplicate. At this time, with respect to the overlapping nozzles, which nozzle is used to form the dots may be controlled by determining an appropriate overlapping nozzle map as in the first embodiment, or may be randomly determined for each pixel. Good.

FIG. 23 shows a configuration in which the number of nozzles used for each color ink is 11, cyan ink, magenta ink, and black ink precede, and yellow ink follows. In this configuration, the paper feed amount can be increased to 11 and the printing speed can be increased when the same raster is not scanned twice. In the example shown in FIG. 23, since the cyan ink, the magenta ink, and the black ink are printed at the same time, the effect of expanding the color gamut is slightly reduced as compared with the configurations of FIGS. But it works well.

D. Fourth Embodiment:
FIG. 24 is a diagram showing a schematic configuration of the printing system 10A according to the fourth embodiment of the present invention. The printing system 10A is different from the printing system 10 of the first embodiment, and the printer driver 24A incorporated in the operating system installed in the computer 100A includes the selection module 48. Further, the printing system 10A can form a plurality of types of dots having different sizes. The printer driver 24A appropriately changes the size of ink dots (hereinafter, referred to as "output dot size") formed on the print medium according to the image data.

The selection module 48 corresponding to the “selection unit” of the present application causes the user to select the image quality mode by displaying an inquiry on the display 114 or the like as to whether or not to expand the color gamut of the print result. The user can select at least one of a normal mode and a high color development mode as the image quality mode. The normal mode prints in a predetermined color gamut, and the high color development mode prints in a wider color gamut than the normal mode. In the high color development mode, the printer driver 24A performs a high color development process that causes at least one of the above-mentioned first process and the second process to be performed.

When the normal mode is selected, the color conversion module 42 uses the color conversion lookup table LUT1 for the normal mode to determine the pixel data of each ink. When the high color development mode is selected, the color conversion module 42 sets the output dot size in the predetermined dark red or dark green, which is the color gamut in which the saturation is improved, when the normal mode is selected. Even if it is the same as the output dot size of, the color conversion lookup table LUT2 optimized for the high color development mode is used to determine the pixel data of each ink. The color gamut that can be reproduced by the color conversion look-up table LUT2 is wider than the color gamut that can be reproduced by the color conversion lookup table LUT1.

The printing mode of the paper feed amount 7 shown in FIG. 9 completes the common print area CA by four main scans. On the other hand, the printing mode of the paper feed amount 9 shown in FIG. 15 is faster than the printing mode of FIG. 9, and the common print area CA is completed by three main scans. Comparing the combination of FIGS. 9 and 4 with the combination of FIGS. 15 and 16, in the printing mode of FIG. 9, all the nozzles are divided into a leading nozzle group and a trailing nozzle group, and there is a clear difference in usage rate between the two. It is possible to increase the effect of expanding the color gamut of the present invention. Therefore, when the high color development mode is selected, the printer driver 24A in the present embodiment adopts the printing mode shown in FIG. 9, which is slow but has a high color gamut expansion effect of the present invention, and the normal mode is selected. Then, for example, by selecting the print mode shown in FIG. 25, which is high-speed but has a small saturation improving effect of the present invention, or the printing mode to which the present invention is not applied, the feed amount in the sub-scanning direction is reduced in the normal print mode. By increasing the number of prints, speed is prioritized over quality.

According to the present embodiment, in a predetermined dark red or dark green, which is a color gamut for improving saturation, color conversion is performed using a lookup table optimized for a high color development mode, so that the color gamut is expanded. It has a large effect and can output red and green with sufficient quality.

Further, when the high color development mode is selected, the feed amount in the sub-scanning direction is reduced as compared with the case where the normal mode is selected. Therefore, printing can be performed by giving priority to quality over speed. In the high color development mode of the present embodiment, it is also possible to adopt a printing mode in which the nozzles are treated as if they are arranged in the sub-scanning direction in a pseudo manner as shown in FIG. The color gamut expansion effect is the highest.

E. Modification example:
<First modification>
In the above-described embodiment, the dye is used as the color material of the ink, but a pigment may be used.

<Second modification>
In the above-described embodiment, printing is performed in the printing system 10 composed of the computer 100 and the printer 200. On the other hand, the printer 200 itself may input image data from a digital camera or various memory cards for printing. That is, the CPU 102 in the control circuit 260 of the printer 200 may perform printing by executing the same processing as the above-mentioned printing processing and halftone processing.

<Third modification example>
In the above-described embodiment, the yellow ink may be ejected from the trailing nozzle only when printing a predetermined dark red color or dark green color.

<Fourth modification>
In the above-described embodiment, the design value of the usage rate when the ink duty is 100% for each nozzle of the nozzle row for cyan and magenta ink shown in FIG. 26 and the design value for each nozzle of the nozzle row for yellow ink shown in FIG. 27. Ink may be ejected using the design value of the usage rate when the ink duty is 100%. By applying such a nozzle utilization characteristic, it is possible to realize a configuration in which the yellow ink is applied after the cyan and magenta inks are completely applied.

<Fifth modification>
In the fourth embodiment described above, high-quality printing is performed by increasing the number of main scans. On the other hand, the main scanning speed of the print head 241 itself may be set to a low speed to perform high-quality and high-saturation printing. Further, after the print head 241 performs one main scan, the time from the start of the next main scan may be lengthened.

<6th modification>
The nozzle pitch, the paper feed amount, and the printing mode (bidirectional printing mode, high color development mode) in the above-described embodiment are examples, and these parameters can be set arbitrarily. For example, the print mode may be a one-way mode in which ink is ejected only when moving forward or backward.

The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations within a range not deviating from the gist thereof. For example, the embodiment corresponding to the technical feature in each embodiment described in the column of the outline of the invention, the technical feature in the modified example, in order to solve the above-mentioned problem, or a part or all of the above-mentioned effect. It is possible to replace or combine as appropriate to achieve this. Further, if the technical feature is not described as essential in the present specification, it can be appropriately deleted.

10, 10A ... printing system, 20 ... application program, 22 ... video driver, 24, 24A ... printer driver, 40 ... image acquisition module, 42 ... color conversion module, 44 ... halftone module, 46 ... print data output module, 100 , 100A ... computer, 102 ... CPU, 114 ... display, 120 ... digital camera, 200 ... printer, 230 ... carriage motor, 231 ... drive belt, 232 ... pulley, 233 ... sliding shaft, 235 ... motor, 236 ... platen, 240 ... Carriage, 241 ... Print head, 243 ... Ink cartridge, 244 to 247 ... Nozzle row, 256 ... Operation panel, 260 ... Control circuit, CA ... Common print area, DM ... Dizamask, IMG ... Image data, LUT, LUT1, LUT2 ... Color conversion lookup table, NM1, NM2, NM3, NM4, NM5 ... Duplicate nozzle map, P ... Print medium

Claims (8)

A printing apparatus that drives and prints a print head relative to a print medium in a main scanning direction that is the width direction of the printing medium and a sub-scanning direction that intersects the main scanning direction.
A print head with a plurality of nozzle rows that eject at least cyan ink, magenta ink, yellow ink, and black ink, respectively.
The acquisition unit that acquires image data and
A dot forming portion that forms dots corresponding to the image data on the printing medium by ejecting ink to the printing medium while scanning the print head in the main scanning direction a plurality of times in a common printing area. , With
Each nozzle row has a preceding nozzle whose scanning timing for ejecting the ink to the common printing area is earlier than that of other nozzles and a scanning timing for ejecting the ink to the common printing area. Including trailing nozzles that are slower than leading nozzles
The dot forming portion is
When printing colors within the color range from red to black
When printing a color that mixes the black ink, the magenta ink, and the yellow ink, the usage rate of the preceding nozzle in the nozzle row of the magenta ink is higher than the usage rate of the preceding nozzle in the nozzle row of the black ink. The usage rate of the trailing nozzle in the yellow ink nozzle row is made higher than the usage rate of the trailing nozzle in the black ink nozzle row, and the usage rate of the trailing nozzle in the yellow ink nozzle row is increased. The first treatment for increasing the rate to be higher than the usage rate of the trailing nozzle in the magenta ink nozzle row, and
When printing colors within the color range from green to black
When printing a color that mixes the black ink, the cyan ink, and the yellow ink, the usage rate of the preceding nozzle in the nozzle row of the cyan ink is higher than the usage rate of the preceding nozzle in the nozzle row of the black ink. The usage rate of the trailing nozzle in the yellow ink nozzle row is made higher than the usage rate of the trailing nozzle in the black ink nozzle row, and the usage rate of the trailing nozzle in the yellow ink nozzle row is increased. Of the second treatment, in which the rate is made higher than the usage rate of the trailing nozzle in the nozzle row of the cyan ink.
A printing device that performs high color development processing that performs at least one of the processing. The printing apparatus according to claim 1.
It is provided with a selection unit capable of selecting at least one of a normal mode for printing in a predetermined color gamut and a high color development mode for printing in a color gamut wider than the normal mode.
The dot forming unit is a printing apparatus that performs the high color development process when the high color development mode is selected. The printing apparatus according to claim 2.
The dot forming unit is a printing device that reduces the amount of feed in the sub-scanning direction when the high color development mode is selected, as compared with the case where the normal mode is selected. The printing apparatus according to claim 2 or 3.
A color conversion look-up table for converting the image data into a value corresponding to the amount of each ink is provided.
The dot forming unit is a printing apparatus that uses the color conversion look-up table that is different even if the ink dot size formed on the print medium is the same in the high color development mode and the normal mode. The printing apparatus according to any one of claims 1 to 4.
In the first treatment, the dot forming portion ejects the magenta ink and the yellow ink from nozzles having different positions in the sub-scanning direction in the respective nozzle rows, and in the second treatment, the cyan A printing device that ejects ink and the yellow ink from nozzles having different positions in the sub-scanning direction in each nozzle row. The printing apparatus according to any one of claims 1 to 5.
The dot forming portion determines the formation of dots by comparing each threshold value of the dither mask composed of a plurality of threshold values with the pixel data constituting the image data.
In the dither mask, the threshold value corresponding to the position where dots are formed by the trailing nozzle that ejects the yellow ink is larger than the threshold value corresponding to the position where dots are formed by the preceding nozzle that ejects the yellow ink. A printing device that is set to a value at which dots are likely to be formed. A print head having a plurality of nozzle rows for ejecting at least cyan ink, magenta ink, yellow ink, and black ink intersects the main scanning direction, which is the width direction of the printing medium, and the main scanning direction with respect to the printing medium. This is a printing method in which printing is performed by driving the ink relative to the sub-scanning direction.
The acquisition process to acquire image data and
A dot forming step of forming dots corresponding to the image data on the printing medium by ejecting ink onto the printing medium while scanning the print head in the main scanning direction a plurality of times in a common printing area. , With
Each nozzle row has a preceding nozzle whose scanning timing for ejecting the ink to the common printing area is earlier than that of other nozzles and a scanning timing for ejecting the ink to the common printing area. Including trailing nozzles that are slower than leading nozzles
In the dot forming step,
When printing colors within the color range from red to black
When printing a color that mixes the black ink, the magenta ink, and the yellow ink, the usage rate of the preceding nozzle in the nozzle row of the magenta ink is higher than the usage rate of the preceding nozzle in the nozzle row of the black ink. The usage rate of the trailing nozzle in the yellow ink nozzle row is made higher than the usage rate of the trailing nozzle in the black ink nozzle row, and the usage rate of the trailing nozzle in the yellow ink nozzle row is increased. The first treatment for increasing the rate to be higher than the usage rate of the trailing nozzle in the magenta ink nozzle row, and
When printing colors within the color range from green to black
When printing a color that mixes the black ink, the cyan ink, and the yellow ink, the usage rate of the preceding nozzle in the nozzle row of the cyan ink is higher than the usage rate of the preceding nozzle in the nozzle row of the black ink. The usage rate of the trailing nozzle in the yellow ink nozzle row is made higher than the usage rate of the trailing nozzle in the black ink nozzle row, and the usage rate of the trailing nozzle in the yellow ink nozzle row is increased. A printing method in which a high color development process is performed in which at least one of the second processes for increasing the rate to be higher than the usage rate of the trailing nozzles in the nozzle row of the cyan ink is performed. A computer provides a printing device with a print head having a plurality of nozzle rows for ejecting at least cyan ink, magenta ink, yellow ink, and black ink , respectively, with respect to the printing medium in the main scanning direction, which is the width direction of the printing medium. It is a computer program for printing by driving relative to each of the sub-scanning directions intersecting the main scanning direction.
The acquisition function to acquire image data and
A dot forming function of forming dots corresponding to the image data on the printing medium by ejecting ink onto the printing medium while scanning the print head in the main scanning direction a plurality of times in a common printing area. , To the computer,
Each nozzle row has a preceding nozzle whose scanning timing for ejecting the ink to the common printing area is earlier than that of other nozzles and a scanning timing for ejecting the ink to the common printing area. Including trailing nozzles that are slower than leading nozzles
The dot forming function is
When printing colors within the color range from red to black
When printing a color that mixes the black ink, the magenta ink, and the yellow ink, the usage rate of the preceding nozzle in the nozzle row of the magenta ink is higher than the usage rate of the preceding nozzle in the nozzle row of the black ink. The usage rate of the trailing nozzle in the yellow ink nozzle row is made higher than the usage rate of the trailing nozzle in the black ink nozzle row, and the usage rate of the trailing nozzle in the yellow ink nozzle row is increased. The first treatment for increasing the rate to be higher than the usage rate of the trailing nozzle in the magenta ink nozzle row, and
When printing colors within the color range from green to black
When printing a color that mixes the black ink, the cyan ink, and the yellow ink, the usage rate of the preceding nozzle in the nozzle row of the cyan ink is higher than the usage rate of the preceding nozzle in the nozzle row of the black ink. The usage rate of the trailing nozzle in the yellow ink nozzle row is made higher than the usage rate of the trailing nozzle in the black ink nozzle row, and the usage rate of the trailing nozzle in the yellow ink nozzle row is increased. A computer program that performs high color development processing that performs at least one of the second processing that causes the rate to be higher than the usage rate of the trailing nozzle in the nozzle row of the cyan ink.

Images