JP2020066209A - Recording control device, recording device and recording control method - Google Patents

Abstract

To improve gloss unevenness.SOLUTION: A recording control device that controls a recording device which performs recording by discharging ink through a nozzle comprises a control part that makes the recording device to record an image in which amounts of ink of a raster line are corrected based on a correction value corresponding to the raster line. The control part executes first correction by which mounts of ink discharged by a first nozzle are increased on the basis of the correction value for a first raster line to be corrected in which amounts of ink are increased based on the correction value, a specific raster line to be recorded by using a first nozzle and a second nozzle which is used less frequently than the first nozzle of the raster lines constituting the image; and executes second correction by which amounts of ink discharged by the second nozzle are decreased on the basis of the correction value for a second raster line to be corrected in which amounts of ink are decreased based on the correction value, the specific raster line.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a recording control device, a recording device, and a recording control method.

  Regarding inkjet printers, there is a technique for suppressing the density difference between raster lines, which is caused by the variation in the ejection characteristics of nozzles, that is, density unevenness, by correcting the density of raster lines that form an image with a correction value for each raster line. It is disclosed (see Patent Document 1).

JP, 2009-220357, A

  However, a part of the raster lines forming the image includes a raster line recorded using a plurality of nozzles. Only by performing the above-mentioned correction, a difference in glossiness is likely to occur in the image recording result when compared with other raster lines recorded by a single nozzle in such a raster line, which may cause a user to feel a difference in glossiness. The gloss unevenness can be visually recognized. Therefore, in addition to suppressing uneven density, improvement for suppressing uneven gloss has been demanded.

  A recording control device for controlling a recording device that ejects ink from a nozzle to perform recording, and causes the recording device to record an image in which an ink amount of a raster line is corrected based on a correction value corresponding to the raster line. A specific raster line recorded by using a first nozzle and a second nozzle having a lower usage ratio than the first nozzle among the raster lines forming the image, A first correction for increasing the amount of ink ejected from the first nozzle based on the correction value is performed on the first raster line to be corrected for increasing the amount of ink based on the correction value. The second nozzle ejects ink to a second raster line that is a raster line and is a correction target for reducing the ink amount based on the correction value. Performing a second correction for reducing based the amount on the correction value.

The figure which shows the schematic structure of a system. FIG. 3 is a diagram simply showing an example of a relationship between a print head and a print medium. The flowchart which shows a correction value acquisition process. The figure which shows an example of a test pattern. FIG. 6 is a diagram illustrating a recording method executed by a printer. The figure which shows an example of a usage ratio table. The figure for demonstrating an example of step S120. The figure which shows an example of a correction value table. 6 is a flowchart showing a recording control process of an input image. The flowchart which shows the detail of step S220. The figure for demonstrating step S240 in 1st Embodiment. The figure for demonstrating step S240 in 2nd Embodiment. FIG. 6 is a diagram for explaining another example of the recording method executed by the printer.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that each drawing is merely an example for explaining the present embodiment. Since each drawing is an example, it may not match with each other, or the description may be omitted as appropriate.

1. System description:
FIG. 1 simply shows the configuration of a system 1 according to this embodiment. The system 1 includes a recording control device 10 and a printer 20. The system 1 may be called a recording system, an image processing system, a printing system, or the like.

  The recording control device 10 is realized by, for example, a personal computer, a smartphone, a tablet terminal, or an information processing device having a processing capacity comparable to those of the personal computer. The recording control device 10 includes a control unit 11, a display unit 13, an operation receiving unit 14, a communication interface 15, and the like. The interface is abbreviated as IF. The control unit 11 is configured to include one or a plurality of ICs having a CPU 11a as a processor, a ROM 11b, a RAM 11c, and the like, and other non-volatile memory.

  In the control unit 11, the processor, that is, the CPU 11a executes arithmetic processing according to a program stored in the ROM 11b, other memory or the like, using the RAM 11c or the like as a work area. For example, the control unit 11 cooperates with the recording control program 12 by executing a process according to the recording control program 12, and cooperates with the recording control program 12a, the correction value calculation unit 12b, and the correction recording control unit 12c. It realizes multiple functions such as. The test pattern is abbreviated as TP. The processor is not limited to one CPU, and may be configured to perform processing by a plurality of CPUs or a hardware circuit such as ASIC, or a configuration in which the CPU and the hardware circuit cooperate to perform processing. May be

  The display unit 13 is means for displaying visual information, and is composed of, for example, a liquid crystal display, an organic EL display, or the like. The display unit 13 may include a display and a driving circuit for driving the display. The operation receiving unit 14 is a unit for receiving an operation by the user, and is realized by, for example, a physical button, a touch panel, a mouse, a keyboard, or the like. Of course, the touch panel may be realized as one function of the display unit 13. The display unit 13 and the operation receiving unit 14 can be collectively referred to as an operation panel of the recording control device 10.

  The display unit 13 and the operation reception unit 14 may be a part of the configuration of the recording control device 10, or may be peripheral devices externally attached to the recording control device 10. The communication IF 15 is a general term for one or a plurality of IFs for the recording control apparatus 10 to execute wired or wireless communication with the outside in accordance with a predetermined communication protocol including a known communication standard. The control unit 11 communicates with the printer 20 via the communication IF 15.

  The printer 20 as a recording device controlled by the recording control device 10 is an inkjet printer that ejects ink dots to perform recording. Dots are also called droplets. Although a detailed description of the inkjet printer is omitted, the printer 20 is roughly provided with a transport mechanism 21, a recording head 22, and the like. The transport mechanism 21 transports the recording medium along a predetermined transport direction. As illustrated in FIG. 2, the recording head 22 includes a plurality of nozzles 23 capable of ejecting dots, and ejects dots from each nozzle 23 onto the recording medium 30 carried by the carrying mechanism 21. The printer 20 controls the application of a drive signal to a drive element (not shown) included in the nozzle 23 according to dot data described below, so that the nozzle 23 ejects dots or does not eject dots. The printer 20 performs printing by, for example, ejecting cyan (C), magenta (M), yellow (Y), and black (K) color inks, or inks and liquids other than these colors. In the present embodiment, the printer 20 will be described as a model that ejects CMYK ink.

  FIG. 2 simply shows the relationship between the recording head 22 and the recording medium 30. The recording head 22 may be called a print head, a print head, a liquid ejection head, or the like. The recording medium 30 is typically paper, but any material other than paper may be used as long as it is a material capable of recording by ejecting liquid. The recording head 22 is mounted on a carriage 24 capable of reciprocating along a predetermined direction D1 and moves together with the carriage 24. The direction D1 is also referred to as the main scanning direction D1. The transport mechanism 21 transports the recording medium 30 in a direction D2 intersecting the direction D1. The direction D2 is the transport direction D2. The term “intersection” here is basically orthogonal, but the directions D1 and D2 may not be strictly orthogonal due to various errors in the printer 20 as a product. The direction D2 is also called the sub-scanning direction D2.

  Reference numeral 25 indicates a nozzle surface 25 in which the nozzle 23 of the recording head 22 is opened. FIG. 2 shows an example of the arrangement of the nozzles 23 on the nozzle surface 25. In the configuration in which the recording head 22 is supplied with ink of each color of CMYK from an ink holding unit (not shown) called an ink cartridge or an ink tank mounted in the printer 20 and ejects the ink from the nozzle 23, the nozzle row 26 for each ink color is formed. Prepare The nozzle row 26 is composed of a plurality of nozzles 23 having a constant nozzle pitch, which is an interval between the nozzles 23 in the transport direction D2. The recording head 22 includes, for example, four nozzle rows 26 corresponding to CMYK inks. Needless to say, the mode of arrangement of the plurality of nozzles 23 forming the nozzle row 26 corresponding to one color of ink does not need to be one linear shape as shown in FIG. 2, and may be divided into a plurality of rows, for example. Good.

  According to the example of FIG. 2, the printer 20 alternately repeats the conveyance of the recording medium 30 by the conveyance mechanism 21 by a predetermined amount and the ink ejection by the recording head 22 in accordance with the movement of the carriage 24. To record to. The ink ejection by the recording head 22 accompanying the forward movement or the backward movement of the carriage 24 along the main scanning direction D1 is also referred to as scanning or pass. According to the example of FIG. 2, the printer 20 is a serial printer in which the recording head 22 mounted on the carriage 24 that reciprocates in the main scanning direction D1 that intersects the transport direction D2 performs recording.

  The recording control device 10 is further connected to the color measurement device 40 so as to be able to communicate. The color measuring device 40 is a general term for devices for measuring the color of the recording medium 30. The color measurement device 40 is, for example, a dedicated color measurement device or a scanner that optically reads an object to generate image data. The color measuring device 40 may be a part of the recording control device 10.

  The recording control device 10 and the printer 20 may be connected via a network (not shown). The printer 20 may be a multifunction peripheral having a plurality of functions such as a scanner function and a facsimile communication function in addition to the printing function. The recording control device 10 may be realized not only by one independent information processing device but also by a plurality of information processing devices communicably connected to each other via a network.

  Alternatively, the recording control device 10 and the printer 20 may be integrated devices. That is, the recording control device 10 is a part of the configuration included in the printer 20 as a recording device, and the process executed by the recording control device 10 described below may be understood as the process executed by the printer 20. .

2. Correction value acquisition process:
FIG. 3 is a flowchart showing a correction value acquisition process realized by the control unit 11 according to the recording control program 12. The correction value is information for suppressing the density unevenness of the raster line due to the variation of the ejection characteristics for each nozzle 23 of the printer 20.

  In step S100, the TP recording control unit 12a causes the printer 20 to record the TP including a plurality of density regions having different densities. TP data, which is image data expressing TP, is prepared in advance in a predetermined memory or the like. The TP data is bitmap data in which each pixel has a gradation value (for example, 256 gradations of 0 to 255) indicating the ink amount for each CMYK. The TP recording control unit 12a performs halftone processing on the TP data. A specific method of halftone processing is not particularly limited, and a dither method, an error diffusion method, or the like can be adopted. By the halftone process, dot data that defines ejection (dot on) or non-ejection (dot off) of dots of CMYK inks is generated for each pixel.

  The TP recording control unit 12a rearranges the generated dot data in the order to be transferred to the printer 20 according to a predetermined recording method. The rearrangement processing is also called rasterization processing. The recording method, which will be described later with reference to FIG. 5, is a recording method adopted by the printer 20 regarding movement of the transport mechanism 21 and the recording head 22. By the rasterizing process, it is determined by which nozzle 23 and at which timing the ink dot defined by the dot data is ejected, according to the pixel position and the ink color. The TP recording control unit 12a transmits the dot data that has been rasterized to the printer 20. As a result, the printer 20 executes recording of the TP on the recording medium 30 based on the dot data transmitted from the recording control device 10.

  FIG. 4 illustrates the TP 50 recorded in the recording medium 30 in step S100. In the TP50, a plurality of elongated concentration regions A1, A2, A3, A4, A5, A6, A7, A8, A9, A10 are arranged in the lateral direction of each concentration region. The density areas A1 to A10 included in the TP50 are different in density from each other and are recorded with the same ink of one color. In the TP 50 shown in FIG. 4, all the density areas A1 to A10 are recorded with K ink. In FIG. 4, in order to facilitate understanding, the densities of the density regions A1 to A10 are illustrated in parentheses. The lowest density area A1 has a density of 10%, and the other density areas A2 to A10 having a higher density than the density area A1 have a high density at 10% intervals.

  The density of a density area means the ratio of dot-on pixels in the area or the coverage of the area with ink. In the TP data representing the TP50, each density area A1 to A10 is a set of pixels having a gradation value corresponding to each density. The density range 0% to 100% can be normalized to the gradation range 0 to 255. Therefore, in the TP data representing the TP50, the density area A1 is, for example, a pixel having a K gradation value “26” corresponding to a density of 10%, that is, (C, M, Y, K) = (0, 0, 0, 26) pixels are formed in a group. In the TP data expressing the TP50, the density area A10 is, for example, a pixel having a K gradation value “255” corresponding to a density of 100%, that is, (C, M, Y, K) = (0, 0, (0,255) pixels are formed together.

  The TP recording controller 12a is oriented so that each nozzle 23 of the nozzle row 26 corresponding to the K ink of the recording head 22 records the density areas A1, A2, A3, A4, A5, A6, A7, A8, A9, A10. , TP50 is recorded in the printer 20. If the printer 20 is a serial printer as described with reference to FIG. 2, the TP recording control unit 12a of the TP recording control unit 12a corresponds to the main scanning direction D1 in the lateral direction of each density area and in the transport direction D2 in the longitudinal direction of each density area. The TP 50 is recorded on the recording medium 30 in the corresponding direction.

  In FIG. 4, the area indicated by the broken line illustrates the raster line RL. The raster line RL is a part of the image, and is an area in which pixels are arranged corresponding to the main scanning direction D1. In step S100, the TP recording controller 12a records one raster line RL for each position of different nozzles 23 in the transport direction D2, thereby recording an image such as a bundle of raster lines RL such as TP50.

  FIG. 5 is a diagram for explaining a recording method that the control unit 11 causes the printer 20 to execute. FIG. 5 exemplifies the correspondence relationship between the nozzle row 26 corresponding to any one of CMYK inks and a part of the image IM to be printed by the printer 20 by the control unit 11. The nozzle row 26 shown in FIG. 5 is a nozzle row 26 including nozzles 23 that eject K ink. The image IM may be, for example, TP50 or an input image described later. Each rectangle forming the image IM is each pixel forming the image IM. As shown in FIG. 4 as well, one area in which the pixels are arranged corresponding to the main scanning direction D1 is one raster line RL that constitutes the image IM.

  In FIG. 5, as an example, the nozzle row 26 corresponding to one color ink is composed of 18 nozzles 23. 5, for convenience of explanation, nozzle numbers # 1, # 2, # 3 ... # 18 are added to the nozzles 23 forming the nozzle row 26 in order from the downstream side to the upstream side in the transport direction D2. There is. FIG. 5 shows that the relative positional relationship between the nozzle row 26 and the image IM in the transport direction D2 changes with each pass of the recording head 22. Of course, the nozzle row 26 does not move to the upstream side in the transport direction D2, but the recording medium 30 is transported to the downstream side in the transport direction D2, so that the nozzles 23 and the image IM as shown in FIG. The positional relationship is realized on the recording medium 30. According to the example of FIG. 5, the control unit 11 causes the printer 20 to convey the recording medium 30 between the pass of the print head 22 and the next pass by a carry amount corresponding to a distance of nozzle pitch × 14. .

  By such conveyance, the raster line RL printed by the nozzle 23 of nozzle number # 15 in the first pass is printed by the nozzle 23 of nozzle number # 1 in the second pass. Similarly, the raster line RL printed by the nozzle 23 of nozzle number # 16 in the first pass is printed by the nozzle 23 of nozzle number # 2 in the second pass, and the raster line RL of nozzle number # 17 in the first pass. The raster line RL printed by the nozzle 23 is printed by the nozzle 23 of nozzle number # 3 in the second pass, and the raster line RL printed by the nozzle 23 of nozzle number # 18 in the first pass is the second pass. No. # 4 nozzle 23 is used for printing. Similarly, the raster line RL printed by the nozzle 23 of nozzle number # 15 in the second pass is printed by the nozzle 23 of nozzle number # 1 in the third pass. In FIG. 5, in order to facilitate understanding, hatching is applied to each raster line RL recorded by a total of two passes, that is, two nozzles 23, and one pass, that is, one nozzle 23 is used for recording. No hatching is applied to each raster line RL.

  Each hatched raster line RL is a specific example of a “specific raster line” recorded by using the “first nozzle” and the “second nozzle”. Each raster line RL that is not hatched is also referred to as a “normal raster line” in order to distinguish it from the specific raster line. In addition, the specific raster line will be described using the code “SRL”. In the rasterizing process, the control unit 11 allocates each pixel forming the image IM, which is dot data, to the nozzle 23 so that the correspondence relationship between the nozzle 23 and the pixel as illustrated in FIG. 5 is realized. In this case, regarding the pixels forming the normal raster line, all the pixels forming the normal raster line may be assigned to one nozzle 23 corresponding to the normal raster line. On the other hand, regarding the specific raster line SRL, it is necessary to distribute the pixels forming the specific raster line SRL to the plurality of nozzles 23 corresponding to the specific raster line SRL.

  FIG. 6 exemplifies the usage ratio table 16 that defines the relationship between the usage ratio of the leading nozzle and the usage ratio of the trailing nozzle used for recording the specific raster line SRL. The nozzle usage ratio means a ratio of pixels assigned as data to the nozzle 23, out of all pixels forming the raster line RL recorded by using a certain nozzle 23. Normally, the usage ratio of one nozzle 23 when printing a raster line is 100%. Note that the pixels forming the raster line RL may have dot-on or dot-off specified. Therefore, the usage ratio of a certain nozzle 23 when recording the raster line RL may not match the ratio of the number of dots actually ejected by the nozzle 23 to the total number of pixels forming the raster line RL. However, it can be said that the number of dots ejected by the nozzle 23 increases in proportion to the usage ratio of the nozzle 23.

  The "preceding nozzle" means the nozzle 23 used first among the two nozzles 23 used for recording the specific raster line SRL, and the "following nozzle" is used for recording the specific raster line SRL. Of the two nozzles 23 used, it means the nozzle 23 used later. According to the example of FIG. 5, when attention is paid to the nozzle 23 of nozzle number # 15 and the nozzle 23 of nozzle number # 1 which are in a relationship of recording together one specific raster line SRL, the nozzle 23 of nozzle number # 15 precedes. The nozzle and the nozzle 23 having the nozzle number # 1 correspond to the subsequent nozzles.

  The vertical axis of the usage ratio table 16 is the POL raster positions (# POL1 to #POLn) in the transport direction D2. “POL” is an abbreviation for partial overlap, and is an expression intended for so-called overlap printing in which one raster line RL is recorded using a plurality of nozzles 23. That is, since the specific raster line SRL is a part of the image and is the raster line RL to be overlap-printed, the position of each specific raster line SRL in the transport direction D2 is expressed as “POL raster position”. . More precisely, the POL raster position is the position of the specific raster line SRL in the “POL area” in which the specific raster line SRL is continuously arranged in the transport direction D2 in the image. Referring to FIG. 5, each of the regions where the hatched specific raster line SRL is continuous for four lines along the transport direction D2 is a POL region. The position # POL1 means the most downstream position in the transport direction D2 in the POL region, and the position #POLn means the most upstream position in the transport direction D2 in the POL region.

  The horizontal axis of the usage ratio table 16 indicates the usage ratio of the leading nozzle and the usage ratio of the trailing nozzle. In FIG. 6, the usage ratio of the leading nozzle is shown by a white area portion, and the usage ratio of the trailing nozzle is shown by a gray area portion. In the usage ratio table 16, the sum of the usage ratio of the leading nozzle and the usage ratio of the trailing nozzle is 100% for any POL raster position. In the usage ratio table 16, the usage ratio of the preceding nozzle is highest at position # POL1 and lowest at position #POLn. In other words, in the usage ratio table 16, the usage ratio of the trailing nozzles is lowest at position # POL1 and highest at position #POLn. That is, the closer the POL raster position is to the position #POLn side from the position # POL1, the lower the usage ratio of the leading nozzles (= the higher the usage ratio of the trailing nozzles). In FIG. 6, the magnitude relationship between the usage ratio of the leading nozzle and the usage ratio of the trailing nozzle changes linearly according to the POL raster position, but may change stepwise, for example.

  In the rasterization processing, the control unit 11 refers to the usage ratio table 16 for the specific raster line SRL among the raster lines RL included in the image IM, and thereby uses the usage ratio of the preceding nozzle and the trailing nozzle according to the POL raster position. Get the nozzle usage ratio. Then, among the pixels forming the specific raster line SRL, the number of pixels corresponding to the usage ratio of the preceding nozzle is assigned to the preceding nozzle, and the remaining pixels corresponding to the usage ratio of the following nozzle are assigned to the succeeding nozzle.

  For example, one specific raster line SRL recorded by the nozzle 23 of nozzle number # 16 and the nozzle 23 of nozzle number # 2, which is one combination of the preceding nozzle and the following nozzle, is assumed as the specific raster line SRL to be processed. To do. When referring to the usage ratio table 16, the control unit 11 acquires the usage ratio of the leading nozzle = 60% and the usage ratio of the trailing nozzle = 40% according to the POL raster position of the specific raster line SRL to be processed. And In this case, the control unit 11 allocates 60% of all the pixels forming the specific raster line SRL to be processed to the nozzle 23 of the nozzle number # 16, and selects all the pixels of the specific raster line SRL to be processed. The remaining 40% of the pixels are allocated to the nozzle 23 having the nozzle number # 2.

  The control unit 11 sets all the specific raster lines SRLs as processing targets and executes such allocation. Further, as shown in FIG. 5, POL regions are repeatedly present in the image IM along the transport direction D2 at predetermined intervals, but the control unit 11 similarly applies the usage ratio table 16 to each of the POL regions. Then, the usage ratio of the leading nozzle and the usage ratio of the trailing nozzle are acquired for each specific raster line SRL. For the sake of space, in FIG. 5, the number of nozzles constituting the nozzle row 26 corresponding to one ink color is 18. However, in the actual recording head 22, the number of nozzles constituting the nozzle row 26 is of course. Is more. In addition, the number of specific raster lines SRL constituting one POL area, that is, the number of raster lines whose positions overlap between an image recorded in one pass and an image recorded in the next pass is also shown in FIG. There may be more than 4 lines as shown in FIG.

  In the present embodiment, one of the “leading nozzle” and the “trailing nozzle” corresponds to the “first nozzle” used for recording the specific raster line SRL, and the other corresponds to recording of the specific raster line SRL. It corresponds to the “second nozzle” that is used and has a lower usage ratio than the first nozzle. Which of the preceding nozzle and the succeeding nozzle corresponds to the first nozzle is determined by the POL raster position of the specific raster line SRL recorded by the preceding nozzle and the succeeding nozzle. Referring to the usage ratio table 16 in FIG. 6, the usage ratio of the leading nozzle and the usage ratio of the trailing nozzle are approximately 50% to 50% at the intermediate position between the position # POL1 and the position #POLn. Therefore, regarding the preceding nozzle and the following nozzle that record the specific raster line SRL of the POL raster position on the position # POL1 side with such an intermediate position as a boundary, the preceding nozzle is the first nozzle and the following nozzle is the second nozzle. Applicable to each On the contrary, regarding the preceding nozzle and the following nozzle that record the specific raster line SRL of the POL raster position on the position #POLn side with the intermediate position as a boundary, the preceding nozzle is the second nozzle and the following nozzle is the first nozzle. Applicable

  Referring to the example of FIG. 5, regarding the combination of the nozzle 23 of nozzle number # 15 and the nozzle 23 of nozzle number # 1 for recording the specific raster line SRL, the nozzle 23 of nozzle number # 15 is the first nozzle and the nozzle number # 1. The one nozzle 23 corresponds to the second nozzle. Similarly, regarding the combination of the nozzle 23 of nozzle number # 16 and the nozzle 23 of nozzle number # 2 for recording the specific raster line SRL, the nozzle 23 of nozzle number # 16 is the first nozzle and the nozzle 23 of nozzle number # 2 is It corresponds to the second nozzle. On the other hand, regarding the combination of the nozzle 23 of nozzle number # 17 and the nozzle 23 of nozzle number # 3 for recording the specific raster line SRL, the nozzle 23 of nozzle number # 17 is the second nozzle and the nozzle 23 of nozzle number # 3 is the second nozzle. It corresponds to one nozzle. Regarding the combination of the nozzle 23 of nozzle number # 18 and the nozzle 23 of nozzle number # 4 for recording the specific raster line SRL, the nozzle 23 of nozzle number # 18 is the second nozzle and the nozzle 23 of nozzle number # 4 is the first nozzle. Corresponds to.

The description will be continued with reference to FIG.
In step S110, the correction value calculation unit 12b acquires the read value of the TP recorded in step S100. In this case, the colorimetric device 40 measures the TP recorded on the recording medium 30, and the correction value calculation unit 12b acquires the read value as the colorimetric result from the colorimetric device 40. The color system adopted by the reading value acquired by the correction value calculating unit 12b is not particularly limited. The correction value calculation unit 12b acquires, for example, the color value represented by the L *, a *, and b * components of the CIE L * a * b * color space defined by the International Commission on Illumination (CIE) as a read value. Alternatively, the image data represented by RGB (red, green, blue) components is acquired as a read value from the color measurement device 40 that is a scanner.

In step S120, the correction value calculation unit 12b calculates a correction value for correcting the ink amount for each raster line RL based on the read value acquired in step S110.
FIG. 7 is a diagram for explaining the process of calculating the correction value in step S120. In FIG. 7, the graph based on the read value acquired in step S110 is shown by a solid line. In FIG. 7, the horizontal axis represents the densities of the density areas A1 to A10 of the TP50, and the vertical axis represents the brightness as the read value. The lightness as the read value is the lightness L * input from the color measuring device 40. Alternatively, the lightness as the read value may be a value calculated by the control unit 11 based on the information input from the color measuring device 40, for example, a value obtained by weighting and adding the RGB components.

  In the graph of FIG. 7, ten black circles at equal intervals in the horizontal axis indicate the brightness of each of the density regions A1 to A10 of TP50. More specifically, each lightness for each density area indicated by these black circles is an average value of lightness for each density area in one raster line RL included in TP50. The solid line connecting the black circles is the function F1 generated by the correction value calculation unit 12b by the interpolation calculation based on the brightness indicated by each black circle. Of course, the interpolation calculation may be linear interpolation.

  In FIG. 7, a function TG indicated by a one-dot chain line is a function serving as a correction reference for density unevenness. The function TG is, for example, a curve generated by performing an interpolation operation on each lightness of each of the density regions A1 to A10 on the target raster line. The target raster line is also one of the raster lines RL included in TP50. There are various methods for determining the target raster line. For example, one nozzle 23 of the nozzles 23 for recording a normal raster line is previously determined as a target nozzle, and the correction value calculation unit 12b sets the raster line RL recorded by this target nozzle as a target raster line. To do. Alternatively, the correction value calculation unit 12b, for example, in the raster line RL included in the TP50, the read value for a specific density area of the density areas A1 to A10 is the raster value that is closest to the predetermined reference brightness. The line RL is determined as the target raster line. Alternatively, the function TG defining ideal values as the read values of the density areas A1 to A10 of the TP50 may be stored in advance in a predetermined memory of the control unit 11.

  According to the example of FIG. 7, the lightness indicated by the function F1 corresponding to the density of 70% is the lightness v1, and the lightness indicated by the function TG corresponding to the same density of 70% is the lightness v2. In this case, the correction value calculation unit 12b sets the density for obtaining the brightness v2 with the function F1 as the corrected density for the density of 70%. The gradation value in the 256 gradation range corresponding to the density of 70% is "k1", and the gradation value in the 256 gradation range corresponding to the corrected density for the density of 70% is "k1 '". Then, the correction value calculation unit 12b sets "k1'-k1" as the correction value for the gradation value k1. For example, if k1 = 170 and k1 ′ = 165, “−5” is the correction value for the gradation value k1. If k1 ′> k1, the correction value for the gradation value k1 is a positive value. The correction value calculation unit 12b calculates the correction value for all the gradation values 0 to 255 including the gradation value k1 by using the function F1 and the function TG.

The correction value calculation unit 12b sequentially targets the raster lines RL included in the TP based on the read values acquired in step S110, and for each raster line RL included in the TP, all the gradation values in the 256 gradation range. A correction value for is calculated. Each raster line RL included in TP naturally includes a normal raster line and a specific raster line SRL.
However, when any one of the raster lines RL included in TP is set as the target raster line, there is substantially no correction value for the target raster line, so the correction value = 0.

In step S130, the correction value calculation unit 12b stores the correction value calculated in step S120 as described above in a predetermined memory of the recording control device 10.
Needless to say, the control unit 11 also calculates and stores the correction value for each of the CMY ink colors other than K as described above. That is, in step S100, the control unit 11 causes the printer 20 to execute not only the recording of the TP with the K ink but also the recording of the TP with each of the CMY inks, and the same from step S110.

  FIG. 8 illustrates the correction value table 17 stored in the recording control device 10 as a result of step S130. The correction value table 17 stores the correction values calculated in step S120, that is, the correction values for each CMYK ink color and for each raster number 1-N. The “correction value 0 to 255” in FIG. 8 is an expression summarizing the existence of each correction value for each gradation value of 0 to 255. The raster number is a number for each raster line RL of an image recorded according to the recording method described above, and the control unit 11 manages the correction value for each raster line RL using the raster number. The raster number is sequentially assigned to each raster line RL that constitutes an image for one page, from the downstream side to the upstream side in the transport direction D2.

3. Recording control process:
First embodiment:
FIG. 9 is a flowchart showing a recording control process for causing the printer 20 to record an arbitrarily selected input image. The recording control process is also realized by the control unit 11 according to the recording control program 12. The recording control process involves a correction process using the correction value calculated as described above. The recording control process includes a control process by the recording control method. Further, the recording control process includes an allocation correction process (step S240) for the specific raster line SRL as one of the features. The embodiment described below will be referred to as a "first embodiment".

  The user arbitrarily selects the image data representing the input image by operating the operation accepting unit 14 while visually checking the user interface screen displayed on the display unit 13, for example. The user interface is abbreviated as UI. In step S200, the correction recording control unit 12c acquires the image data arbitrarily selected by the user from a predetermined input source.

  The image data acquired in step S200 is bitmap data having a plurality of pixels like the TP data, and has, for example, RGB gradation values (for example, 256 gradations of 0 to 255) for each pixel. If the acquired image data does not correspond to such an RGB color system, the correction recording control unit 12c converts the acquired image data into data of the color system. Further, the correction recording control unit 12c appropriately performs a resolution conversion process or the like on the image data so as to match the printing resolution adopted by the printer 20.

  In step S210, the correction recording control unit 12c executes the color conversion process on the image data after step S200. That is, the color system of the image data is converted into the color system of the ink used by the printer 20 for recording. As described above, when the image data represents the gradation of the color of each pixel in RGB, the gradation value of RGB is converted into the gradation value of CMYK for each pixel. The color conversion process can be executed by referring to an arbitrary color conversion lookup table that defines a conversion relationship from RGB to CMYK.

In step S220, the correction recording control unit 12c stores in the correction value table 17 the image data after color conversion obtained in step S210, that is, the image data in which each pixel has a gradation value indicating the ink amount for each CMYK. It corrects using the corrected value.
FIG. 10 is a flowchart showing details of the correction process in step S220.
In step S221, the correction recording control unit 12c selects one pixel to be corrected from the plurality of pixels forming the image data.
In step S222, the correction recording control unit 12c selects one gradation value of the ink color to be corrected from the gradation values of each CMYK included in the pixel selected in step S221.

  In step S223, the correction recording control unit 12c sets the correction value corresponding to the raster number of the raster line RL to which the pixel selected in step S221 belongs and the correction value corresponding to the ink color selected in step S222 to the correction value. The gradation value of the ink color selected in step S222 is corrected based on the correction value read from the table 17. For example, it is assumed that the pixel belonging to the raster line RL with the raster number = 1 is selected in step S221, and the gradation value of the K ink of this pixel, for example, the gradation value = 50, is selected in step S222. In this case, in step S223, the correction recording control unit 12c reads from the correction value table 17 the correction value for the correction of the gradation value = 50 corresponding to the raster number = 1 and the K ink.

In step S224, the correction recording control unit 12c determines whether or not the correction in step S223 has been completed for the tone values of all the ink colors CMYK that the pixels selected in step S221 have, and some ink colors have not been corrected. In this case, the process returns to step S222 to newly select the gradation value of the uncorrected ink color. On the other hand, when the correction of the gradation values of all the ink colors CMYK in step S223 is completed, the process proceeds to step S225.
In step S225, the correction recording control unit 12c determines whether or not the correction has been completed for all the pixels that form the image data. If there is a pixel that has not been corrected, the process returns to step S221 and the uncorrected pixel Is newly selected. On the other hand, when the correction of all pixels is completed, the correction process of step S220 is completed.

  In step S230, the correction recording control unit 12c performs halftone processing on the image data after the correction processing in step S220 to generate dot data.

  In step S240, the correction recording control unit 12c executes the allocation correction process for the specific raster line SRL among the raster lines RL that form the dot data generated in step S230. Of the raster lines RL that form the dot data generated in step S230, the normal raster line is not the target of the allocation correction process.

FIG. 11 is a diagram for explaining the allocation correction process in the first embodiment.
FIG. 11 illustrates the POL mask 18. The POL mask 18 is a mask for applying the specific raster line SRL by superimposing it on the POL region continuous in the transport direction D2. In the POL mask 18, values that define to which of the leading nozzles and the trailing nozzles the pixels forming the image to be applied are assigned are stored in a matrix. In the example of FIG. 11, the value “1” means that the allocation destination is the leading nozzle, and the value “0” means that the allocation destination is the trailing nozzle. Each horizontal row of the POL mask 18 is applied to each specific raster line SRL forming the POL area.

  That is, the POL mask 18 is a mask for specifically realizing the pixel allocation to the leading nozzle and the trailing nozzle based on the usage ratio table 16 illustrated in FIG. In step S100 of the correction value acquisition process described above, such a POL mask 18 is applied to the POL area of the dot data expressing the TP so that each pixel that constitutes the specific raster line SRL is a preceding nozzle or a trailing nozzle. The TP is assigned to the nozzle, and as a result, the TP is recorded on the recording medium 30.

  In FIG. 11, for ease of understanding, for each row of the POL mask 18, the POL raster position (# POL1 to #POLn (where n = 4)) and the usage ratio of the preceding nozzle, that is, the value “1” in the row. And the ratio of. The number of rows of the POL mask 18 is set to 4 in FIG. 11 in accordance with the example in which one POL region is configured by the four specific raster lines SRL continuous in the transport direction D2 as shown in FIG. In FIG. 11 as described above, the POL mask 18 in which the usage ratio of the preceding nozzles applied to the specific raster line SRL corresponding to the position # POL1 in the POL region is defined as 80% is shown. Further, the POL mask 18 has a usage ratio of the preceding nozzles applied to the specific raster line SRL corresponding to the position # POL2 is 60%, a usage ratio of the preceding nozzles applied to the specific raster line SRL corresponding to the position # POL3 is 40%, The usage ratio of the preceding nozzle applied to the specific raster line SRL corresponding to the position # POL4 is defined as 20%.

  The usage ratio of the succeeding nozzles of each row of the POL mask 18, that is, the ratio of the value “0” in the row is a value obtained by subtracting the usage ratio of the preceding nozzle from 100%. According to the example of FIG. 11, the preceding nozzles used for recording the specific raster line SRL corresponding to the position # POL1 and the preceding nozzles used for recording the specific raster line SRL corresponding to the position # POL2 are respectively It corresponds to one nozzle. On the other hand, the preceding nozzle used for recording the specific raster line SRL corresponding to the position # POL3 and the preceding nozzle used for recording the specific raster line SRL corresponding to the position # POL4 respectively correspond to the second nozzle.

  The correction recording control unit 12c corrects the POL mask 18 based on the correction value for each specific raster line SRL of the POL region to which the POL mask 18 is applied. Here, among the dot data for each CMYK generated in step S230, four continuous raster numbers i, i + 1, i + 2, and i + 3 of the specific raster lines in the dot data that defines the dot on / off of the K ink are specified. It is assumed that the POL area configured by SRL is the processing target of step S240. However, i + 3 ≦ N. In the example of FIG. 11, the correction values corresponding to the raster numbers i, i + 1, i + 2, i + 3 are “+ 5%”, “−10%”, “−5%”, and “+ 3%”. The correction value corresponding to the raster number is the correction value defined in the correction value table 17.

  The correction value table 17 defines “correction values 0 to 255” for each ink color and each raster number. Therefore, when the POL mask 18 is corrected, the correction recording control unit 12c uses the "correction value 0 to 255" defined in the correction value table 17 as a representative correction value corresponding to the ink color and the raster number. Is determined, and the determined correction value may be used. The correction recording control unit 12c reads, for example, “correction values 0 to 255” corresponding to the K ink and the raster number i from the correction value table 17, and the average value of the read “correction values 0 to 255” is set to the K ink. Moreover, the correction value corresponding to the raster number i is determined. Alternatively, the correction recording control unit 12c, among the “correction values 0 to 255” corresponding to the K ink and the raster number i, in the correction process of step S220, the gradation of the K ink of each pixel of the raster line RL of the raster number i. The correction value actually applied to the value is extracted. Then, the average value of the correction values thus extracted may be determined as the correction value corresponding to the K ink and the raster number i.

  In this way, the correction recording control unit 12c acquires each correction value of the raster numbers i, i + 1, i + 2, i + 3 as illustrated in FIG. According to the description of the correction value acquisition process, the correction value is a value for correcting the ink amount according to the gradation value in the gradation range of 0 to 255, but in FIG. It is rewritten and shown. For example, the correction value “+ 5%” corresponding to the raster number i is the gradation value of K of each pixel of the specific raster line SRL of the raster number i in the correction process of step S220, which is about a gradation value of 255 on average. It means that the gradation value is increased by 5%. Further, the correction value “−10%” corresponding to the raster number i + 1 indicates that the gradation value of K of each pixel of the specific raster line SRL of the raster number i + 1 is about the gradation value on average in the correction process of step S220. This means that the gradation value corresponding to 10% of 255 has decreased.

  According to the above example, the raster number i corresponds to the position # POL1 in the POL area. Therefore, the correction recording control unit 12c corrects the nozzle usage ratio corresponding to the position # POL1 of the POL mask 18 by the correction value of the raster number i. Similarly, the correction recording control unit 12c corrects the nozzle usage ratio corresponding to the position # POL2 of the POL mask 18 by the correction value of the raster number i + 1, and the position # of the POL mask 18 by the correction value of the raster number i + 2. The nozzle usage ratio corresponding to POL3 is corrected, and the nozzle usage ratio corresponding to position # POL4 of the POL mask 18 is corrected using the correction value of raster number i + 3. In FIG. 11, the corrected POL mask 18 is shown as a corrected POL mask 19.

  At this time, the correction recording control unit 12c determines, based on the correction value, the ink amount ejected by the “first nozzle” for the “first raster line” that is the specific raster line SRL and is the correction target for increasing the ink amount. The “first correction” that causes the increase is executed. Further, the correction recording control unit 12c reduces the ink amount ejected by the "second nozzle" with respect to the "second raster line" that is the specific raster line SRL and is the correction target for reducing the ink amount, based on the correction value. The “second correction” that causes the above is executed.

  Specifically, the correction value “+ 5%” for the raster number i is a correction value for increasing the ink amount. Therefore, the correction recording control unit 12c adds 5% to the usage ratio “80%” of the preceding nozzle (first nozzle) corresponding to the position # POL1 of the POL mask 18 to obtain “85%”. In the corrected POL mask 19, for the sake of easy understanding, a portion whose value is changed from the POL mask 18 is colored gray. That is, the correction recording control unit 12c changes the usage ratio of the preceding nozzle (first nozzle) by changing at least a part of the value “0” in the row of the position # POL1 of the POL mask 18 to the value “1”. Increase from 80% to 85%. Such a change to the row at position # POL1 corresponds to a specific example of the first correction.

  The correction value "-10%" for the raster number i + 1 is a correction value for reducing the ink amount. Therefore, the correction recording control unit 12c adds −10% to the usage ratio “40%” of the trailing nozzle (second nozzle) corresponding to the position # POL2 of the POL mask 18 to obtain “30%”. Setting the usage ratio of the trailing nozzle to “30%” is equivalent to setting the usage ratio of the leading nozzle to “70%”. The correction recording control unit 12c changes at least a part of the value “0” in the row of the position # POL2 of the POL mask 18 to the value “1”, so that the usage ratio of the succeeding nozzles (second nozzles) becomes 40. % To 30%. Such a change to the row at position # POL2 corresponds to a specific example of the second correction.

  The correction value “−5%” for the raster number i + 2 is a correction value for reducing the ink amount. Therefore, the correction recording control unit 12c adds −5% to the usage ratio “40%” of the preceding nozzle (second nozzle) corresponding to the position # POL3 of the POL mask 18 to obtain “35%”. The correction recording control unit 12c changes the usage ratio of the preceding nozzle (second nozzle) to 40% by changing at least a part of the value “1” in the row of the position # POL3 of the POL mask 18 to the value “0”. To 35%. Such a change to the row at position # POL3 corresponds to a specific example of the second correction.

  The correction value “+ 3%” for the raster number i + 3 is a correction value for increasing the ink amount. Therefore, the correction recording control unit 12c adds 3% to the usage ratio “80%” of the trailing nozzle (first nozzle) corresponding to the position # POL4 of the POL mask 18 to obtain “83%”. Setting the usage ratio of the trailing nozzle to “83%” is equivalent to setting the usage ratio of the leading nozzle to “17%”. The correction recording control unit 12c changes at least a part of the value “1” in the row of the position # POL4 of the POL mask 18 to the value “0” to set the usage ratio of the subsequent nozzles (first nozzles) to 80. % To 83%. Such a change to the line at position # POL4 corresponds to a specific example of the first correction.

  The correction recording control unit 12c superimposes and applies the correction POL mask 19 on the POL area formed by the specific raster lines SRL of the raster numbers i, i + 1, i + 2, and i + 3 described above. As a result, the correction recording control unit 12c assigns each pixel forming each specific raster line SRL to the preceding nozzle or the following nozzle according to the values “1” and “0” defined in the correction POL mask 19. The correction recording control unit 12c repeatedly executes such allocation correction processing in step S240 for each POL area included in each of the CMYK dot data generated in step S230. Even if the POL mask 18 is one mask, the correction POL mask 19 has different contents for each POL region to be processed.

  In step S250, the correction recording control unit 12c performs an output process that causes the printer 20 to execute recording based on the dot data generated in step S230. That is, the correction recording control unit 12c performs the rasterizing process on the dot data according to the recording method, and transmits the dot data after the rasterizing process to the printer 20. Of the dot data, the correction recording control unit 12c naturally transmits each pixel forming the specific raster line SRL to the printer 20 according to the allocation to the preceding nozzle and the following nozzle in step S240. As a result, the printer 20 executes the recording of the input image on the recording medium 30 based on the dot data transmitted from the recording control device 10.

The effect of the first embodiment will be described.
It is assumed that the correction processing of step S220 has performed correction for increasing the gradation value indicating the ink amount for the specific raster line SRL with the raster number i. By the correction process of step S220, the total number of dots ejected by each of the preceding nozzle and the following nozzle for recording the specific raster line SRL having the raster number i increases. The increase / decrease in the ink amount can also be regarded as an increase / decrease in the number of dots ejected by the recording head 22. The specific raster line SRL with the raster number i is corrected to increase the ink amount and corresponds to the “first raster line”. Therefore, according to the allocation correction process in step S240, the nozzle 23 (first nozzle) whose usage ratio is set to be high in advance of the preceding nozzle and the following nozzle that record the specific raster line SRL of the raster number i. The use ratio of is further increased based on the correction value of the raster number i. As a result, when the first nozzle prints the specific raster line SRL with the raster number i, all or most of the increased ink amount due to the correction process in step S220 for the specific raster line SRL with the raster number i is recorded. This is the amount of increase in the amount of ink (number of dots) ejected to.

  Further, it is assumed that the correction processing of step S220 has performed correction for reducing the gradation value indicating the ink amount for the specific raster line SRL of the raster number i + 1. By the correction process in step S220, the total number of dots ejected by each of the preceding nozzles and the following nozzles for recording the specific raster line SRL having the raster number i + 1 is reduced. The specific raster line SRL with the raster number i + 1 is corrected to reduce the ink amount and corresponds to the “second raster line”. Therefore, according to the allocation correction process of step S240, the nozzle 23 (second nozzle) whose use ratio is set to be low in advance of the preceding nozzle and the following nozzle that record the specific raster line SRL of the raster number i + 1. The use ratio of is further reduced based on the correction value of the raster number i + 1. As a result, when the second nozzle prints the specific raster line SRL of the raster number i + 1, all or most of the ink amount of the decrease amount due to the correction process of step S220 for the specific raster line SRL of the raster number i + 1 is recorded. It corresponds to the decrease in the amount of ink (the number of dots) ejected to.

  Of the raster lines RL forming the input image, the normal raster line is printed by one nozzle 23 in one pass. Therefore, the dots ejected onto the recording medium 30 for recording a raster line usually have a small time difference when landed on the recording medium 30, and as a result, are easily fixed on the recording medium 30 with little unevenness between dots. . On the other hand, of the raster lines RL forming the input image, the specific raster line SRL is printed by the preceding nozzle and the succeeding nozzle in a total of two passes. Therefore, there is a time difference between the landing of the dots ejected by the preceding nozzles on the recording medium 30 and the landing of the dots ejected by the trailing nozzles on the recording medium 30, and as a result, the specific raster line SRL is recorded. It is easy for each of the dots to be fixed to the recording medium 30 in a state where the unevenness between the dots is large. Comparing the normal raster line and the specific raster line SRL in the recording result, the normal raster line having less unevenness between dots has a higher gloss feeling. Therefore, in the conventional recording result of the input image, a difference in gloss feeling occurs between the area formed by the normal raster line and the area formed by the specific raster line SRL, that is, the POL area, which is visually recognized as uneven gloss. There was something.

  To solve such a problem, according to the first embodiment, in the configuration in which the ink amount is corrected for each raster line RL by the correction value for correcting the density unevenness for each raster line RL, the specific raster line SRL is also added. The difference between the amount of ink ejected by the first nozzle and the amount of ink ejected by the second nozzle for recording is increased. That is, the number of dots ejected for recording the specific raster line SRL is biased to one of the preceding nozzle and the following nozzle as compared with the conventional case. As a result, it is possible to suppress the unevenness between dots due to the time difference of the landing of dots on the recording medium 30 with respect to the specific raster line SRL as much as possible, and suppress the above-described gloss unevenness.

  In the example described with reference to FIG. 11, assuming that the correction value of the raster number i is “+ 10%” and the usage ratio of the preceding nozzle (first nozzle) corresponding to the position # POL1 of the POL mask 18 is “ In the case of "95%", if 10% is added to 95%, it will exceed 100%. In such a case, the ink for correcting the usage rate of the first nozzle to 100% (the usage rate of the second nozzle is 0%) and recording the specific raster line SRL of the raster number i is corrected in step S220. All the ink is recorded by the first nozzle, including the increase in the ink amount due to the processing. Further, in the example described with reference to FIG. 11, if the correction value of the raster number i + 3 is “−10%”, the usage ratio of the preceding nozzle (second nozzle) corresponding to the position # POL4 of the POL mask 18 is set. In the case of "5%", if -10% is added to 5%, it will be less than 0%. In such a case, the ink for correcting the usage ratio of the second nozzle to 0% (the usage ratio of the first nozzle is 100%) and recording the specific raster line SRL of the raster number i + 3 is corrected in step S220. All the ink amounts after the reduction of the ink amount due to the processing is reflected are recorded by the first nozzle.

4. Second embodiment:
Next, a second embodiment will be described. Regarding the second embodiment, points different from the above description will be mainly described.
FIG. 12 is a diagram for explaining the allocation correction process (step S240) for the specific raster line SRL in the second embodiment. In the second embodiment, step S240 will be described as a process included in the halftone process of step S230. In the second embodiment, the dot data is directly corrected instead of correcting the POL mask as described in the first embodiment.

The correction recording control unit 12c generates pass dot data to be assigned to each pass from the dot data generated by the halftone process. The dot data for pass includes raster lines RL having the number of lines corresponding to the number of nozzles of the nozzle row 26.
The dot data KD1 shown in FIG. 12 is, for example, pass dot data for allocating to the nozzle row 26 of K ink corresponding to the first pass of the print head 22. Further, the dot data KD2 is pass dot data for allocating to the nozzle row 26 of K ink corresponding to the second pass of the print head 22. Each of the dot data KD1 and KD2 defines dot-on or dot-off of K ink for each pixel. The rectangles that form the dot data KD1 and KD2 are the pixels that form the dot data KD1 and KD2. In FIG. 12, the row in which the pixels are arranged in the horizontal direction is the raster line RL. In FIG. 12, a part of each of the dot data KD1 and KD2 is shown.

  According to FIG. 12, the dot data KD1 is composed of four continuous raster numbers i, i + 1, i + 2, and i + 3 of specific raster lines SRL, and a plurality of normal raster lines having raster numbers smaller than the raster number i. ing. The raster line RL having a raster number i−1 that is one smaller than the raster number i is a normal raster line. The dot data KD2 is composed of continuous specific raster lines SRL of four raster numbers i, i + 1, i + 2, i + 3 and a plurality of normal raster lines having a raster number larger than the raster number i + 3. The raster line RL with the raster number i + 4, which is one greater than the raster number i + 3, is a normal raster line. Each specific raster line SRL of raster numbers i, i + 1, i + 2, i + 3 included in the dot data KD1 and each specific raster line SRL of raster numbers i, i + 1, i + 2, i + 3 included in the dot data KD2 respectively pass. The data is exactly the same when it is generated as the use dot data. That is, the dot data KD1 and KD2 share one POL area. The lower end side (not shown) of the dot data KD2 includes a POL area that is shared with pass dot data for allocating to the nozzle row 26 of K ink corresponding to the third pass of the print head 22.

  In FIG. 12, the raster nozzle numbers and the usage ratios of the preceding nozzles are added to correspond to the specific raster lines SRL that make up the dot data KD1. Further, the raster number and the usage ratio of the succeeding nozzles are additionally described in association with each specific raster line SRL forming the dot data KD2. The use ratio of the preceding nozzle and the use ratio of the following nozzle are values determined by the use ratio table 16 according to the position of the specific raster line SRL in the POL region, that is, the POL raster position. As shown with respect to the dot data KD1 and KD2, the sum of the usage ratio of the leading nozzle and the usage ratio of the trailing nozzle, which have a common raster number, is 100%.

  The correction recording control unit 12c determines whether each pixel forming the specific raster line SRL included in the dot data KD1 is an effective pixel or an invalid pixel according to the usage ratio of the preceding nozzle. For example, in the case of the specific raster line SRL of the raster number i included in the dot data KD1, the correction recording control unit 12c determines that 80% of the pixels are effective pixels because the usage rate of the preceding nozzle is 80%, and the remaining 20% of pixels are invalid pixels. Similarly, in the case of the specific raster line SRL of the raster number i + 1 included in the dot data KD1, since the usage ratio of the preceding nozzle is 60%, 60% of the pixels are valid pixels and the remaining 40% of pixels are invalid. Pixels. Similarly, for the dot data KD2, the correction recording control unit 12c determines whether each pixel forming the specific raster line SRL is an effective pixel or an invalid pixel according to the usage ratio of the subsequent nozzles. For example, in the case of the specific raster line SRL of the raster number i included in the dot data KD2, the correction recording control unit 12c uses the trailing nozzles at a usage rate of 20%, so that 20% of the pixels are effective pixels and the remaining pixels are the remaining pixels. 80% of the pixels are set as invalid pixels. The correction recording control unit 12c may set a pixel, which is an effective pixel among the pixels forming the specific raster line SRL in the dot data KD1, as an invalid pixel in the dot data KD2.

  In the example of FIG. 12, among the pixels included in the dot data KD1 and KD2, the gray-colored pixels are invalid pixels and the white pixels are valid pixels. The effective pixel is the pixel itself whose dot-on or dot-off is defined by the halftone process. On the other hand, an invalid pixel is a pixel that is forcibly turned off regardless of whether dot-on or dot-off is defined. The correction recording control unit 12c replaces a pixel determined to be an invalid pixel with dot off if it is dot on. The value “0” described in the invalid pixel in FIG. 12 means that the dot is off. Note that, as shown in FIG. 12, all the pixels forming the normal raster line remain effective pixels. In addition, "100%" added to the normal raster line means that all the pixels forming the normal raster line are assigned to one nozzle 23 in the state of effective pixels.

  Such dot data KD1 and KD2 are substantially the same as the result when the POL mask 18 shown in FIG. 11 is applied to the POL area of the dot data after the halftone process in the first embodiment. Therefore, the correction recording control unit 12c corrects the dot data KD1 and KD2 based on the correction value for each specific raster line SRL. Similar to FIG. 11, FIG. 12 shows the correction values “+ 5%”, “−10%”, “−5%”, and “+ 3%” corresponding to the raster numbers i, i + 1, i + 2, and i + 3.

  The correction recording control unit 12c corrects either the specific raster line SRL of the raster number i of the dot data KD1 or the specific raster line SRL of the raster number i of the dot data KD2 by the correction value of the raster number i. Further, the correction recording control unit 12c corrects either the specific raster line SRL of the raster number i + 1 of the dot data KD1 or the specific raster line SRL of the raster number i + 1 of the dot data KD2 with the correction value of the raster number i + 1. Further, the correction recording control unit 12c corrects either the specific raster line SRL of the raster number i + 2 of the dot data KD1 or the specific raster line SRL of the raster number i + 2 of the dot data KD2 by the correction value of the raster number i + 2. Further, the correction recording control unit 12c corrects either the specific raster line SRL of the raster number i + 3 of the dot data KD1 or the specific raster line SRL of the raster number i + 3 of the dot data KD2 by the correction value of the raster number i + 3.

  At this time, the correction recording control unit 12c determines, based on the correction value, the ink amount ejected by the “first nozzle” for the “first raster line” that is the specific raster line SRL and is the correction target for increasing the ink amount. The “first correction” that causes the increase is executed. Further, the correction recording control unit 12c reduces the ink amount ejected by the "second nozzle" with respect to the "second raster line" that is the specific raster line SRL and is the correction target for reducing the ink amount, based on the correction value. The “second correction” that causes the above is executed.

  Specifically, the correction value “+ 5%” for the raster number i is a correction value for increasing the ink amount. Therefore, the correction recording control unit 12c corrects the specific raster line SRL recorded by the preceding nozzle (first nozzle) corresponding to the raster number i, that is, the specific raster line SRL of the raster number i of the dot data KD1. The specific raster line SRL with the raster number i of the dot data KD2 is not corrected. In this case, the correction recording control unit 12c restores at least a part of the invalid pixels in the specific raster line SRL of the raster number i of the dot data KD1 to the original effective pixels, and thus the specific raster of the raster number i of the dot data KD1. The ratio of effective pixels in the line SRL is increased from 80% to 85%. The correction for the specific raster line SRL of the raster number i of the dot data KD1 corresponds to a specific example of the first correction.

  In FIG. 12, the corrected dot data KD1 is shown as corrected dot data KD1 ′, and the corrected dot data KD2 is shown as corrected dot data KD2 ′. Further, in the corrected dot data KD1 ′ and KD2 ′, for easy understanding, the pixels corrected from the dot data KD1 and KD2 are shown surrounded by a thick frame. The numerical value such as 85% added together with the raster number corresponding to each specific raster line SRL of the corrected dot data KD1 ′, KD2 ′ is the ratio of effective pixels in the specific raster line SRL.

  The correction value "-10%" for the raster number i + 1 is a correction value for reducing the ink amount. Therefore, the correction recording control unit 12c corrects the specific raster line SRL recorded by the succeeding nozzle (second nozzle) corresponding to the raster number i + 1, that is, the specific raster line SRL having the raster number i + 1 of the dot data KD2. The specific raster line SRL having the raster number i + 1 of the dot data KD1 is not corrected. In this case, the correction recording control unit 12c sets at least a part of the valid pixels in the specific raster line SRL of the raster number i + 1 of the dot data KD2 to invalid pixels, so that the specific raster line SRL of the raster number i + 1 of the dot data KD2. The ratio of effective pixels within is reduced from 40% to 30%. The correction for the specific raster line SRL of the raster number i + 1 of the dot data KD2 corresponds to a specific example of the second correction.

  The correction value “−5%” for the raster number i + 2 is a correction value for reducing the ink amount. Therefore, the correction recording control unit 12c corrects the specific raster line SRL recorded by the preceding nozzle (second nozzle) corresponding to the raster number i + 2, that is, the specific raster line SRL of the raster number i + 2 of the dot data KD1. The specific raster line SRL of the raster number i + 2 of the dot data KD2 is not corrected. In this case, the correction recording control unit 12c sets at least a part of the valid pixels in the specific raster line SRL of the raster number i + 2 of the dot data KD1 to invalid pixels, so that the specific raster line SRL of the raster number i + 2 of the dot data KD1. The ratio of effective pixels within is reduced from 40% to 35%. The correction for the specific raster line SRL with the raster number i + 2 of the dot data KD1 corresponds to a specific example of the second correction.

  The correction value “+ 3%” for the raster number i + 3 is a correction value for increasing the ink amount. Therefore, the correction recording control unit 12c corrects the specific raster line SRL recorded by the succeeding nozzle (first nozzle) corresponding to the raster number i + 3, that is, the specific raster line SRL of the raster number i + 3 of the dot data KD2. The specific raster line SRL of the raster number i + 3 of the dot data KD1 is not corrected. In this case, the correction recording control unit 12c returns at least a part of the invalid pixels in the specific raster line SRL of the raster number i + 3 of the dot data KD2 to the effective pixels, and thus the specific raster line SRL of the raster number i + 3 of the dot data KD2. The ratio of effective pixels within is increased from 80% to 83%. The correction for the specific raster line SRL of the raster number i + 3 of the dot data KD2 corresponds to a specific example of the first correction.

The correction recording control unit 12c repeatedly executes the correction processing for each POL area in the pass dot data based on each of the CMYK dot data generated by the halftone processing.
In step S250, the correction recording control unit 12c performs an output process that causes the printer 20 to execute recording based on the pass dot data obtained through steps S230 and S240. The correction recording control unit 12c may transmit the pass dot data to the printer 20 in association with the pass order. Among the pixels included in the POL region in the pass dot data, that is, the specific raster line SRL, the invalid pixel is always dot-off even if it is assigned to the nozzle 23 in each pass. As a result, the printer 20 executes the recording of the input image on the recording medium 30 based on the dot data transmitted from the recording control device 10.

The effect of the second embodiment will be described.
It is assumed that the correction processing of step S220 has performed correction for increasing the gradation value indicating the ink amount for the specific raster line SRL with the raster number i. By the correction process of step S220, the total number of dots ejected by each of the preceding nozzle and the following nozzle for recording the specific raster line SRL having the raster number i increases. The specific raster line SRL with the raster number i is corrected to increase the ink amount and corresponds to the “first raster line”. Therefore, according to step S240 of the second embodiment, of the preceding nozzle and the following nozzle that record the specific raster line SRL of the raster number i, the nozzle 23 (first nozzle) whose usage ratio is set to a high value in advance is used. ), The number of effective pixels to be allocated further increases based on the correction value of the raster number i. As a result, most of the increased ink amount due to the correction process of step S220 for the specific raster line SRL of raster number i is ejected when the first nozzle records the specific raster line SRL of raster number i. The increase is the amount of ink (number of dots) to be used.

  Further, it is assumed that the correction processing of step S220 has performed correction for reducing the gradation value indicating the ink amount for the specific raster line SRL of the raster number i + 1. By the correction process in step S220, the total number of dots ejected by each of the preceding nozzles and the following nozzles for recording the specific raster line SRL having the raster number i + 1 is reduced. The specific raster line SRL with the raster number i + 1 is corrected to reduce the ink amount and corresponds to the “second raster line”. Therefore, according to step S240 of the second embodiment, of the preceding nozzle and the following nozzle that record the specific raster line SRL with the raster number i + 1, the nozzle 23 (second nozzle) whose usage ratio is set to a low value in advance is used. ), The number of effective pixels to be allocated is further reduced based on the correction value of the raster number i + 1. As a result, most of the reduced ink amount resulting from the correction process of step S220 for the specific raster line SRL of raster number i + 1 is ejected when the second nozzle prints the specific raster line SRL of raster number i + 1. The amount of ink used (number of dots) decreases.

  According to the second embodiment as well, in the configuration in which the ink amount is corrected for each raster line RL by the correction value for correcting the density unevenness for each raster line RL, the specific raster line SRL is also recorded. The difference between the amount of ink ejected by the first nozzle and the amount of ink ejected by the second nozzle is made larger. Therefore, similar to the first embodiment, regarding the specific raster line SRL, it is possible to suppress the unevenness between the dots due to the time difference of the landing of the dots on the recording medium 30 as much as possible, and improve the above-described gloss unevenness.

5. Summary:
As described above, according to the present embodiment, the recording control device 10 controls the printer 20 as a recording device that ejects ink from the nozzles 23 to perform recording. The recording control device 10 includes a control unit 11 that causes the printer 20 to record an image in which the ink amount of the raster line RL is corrected based on the correction value corresponding to the raster line RL. Then, the control unit 11 is the specific raster line SRL recorded by using the first nozzle and the second nozzle having a lower usage ratio than the first nozzle among the raster lines RL constituting the image, and the correction A first correction for increasing the amount of ink ejected from the first nozzle based on the correction value is performed on the first raster line to be corrected for increasing the amount of ink based on the value. The control unit 11 is a specific raster line SRL, and based on the correction value, the ink amount ejected by the second nozzle with respect to the second raster line that is a target of correction for reducing the ink amount based on the correction value. Then, the second correction is performed to reduce the amount.

  According to the above configuration, the control unit 11 corrects the ink amount of the raster line RL based on the correction value corresponding to the raster line RL. As a result, it is possible to suppress density unevenness of the raster line RL in the recording result. Further, according to the above configuration, the control unit 11 executes the first correction and the second correction to cause the ink amount ejected by the first nozzle and the second nozzle to eject the specific raster line SRL. The difference from the ink amount to be used is increased. As a result, it is possible to suppress gloss unevenness in the recording result.

Further, according to the present embodiment, in the first correction, the control unit 11 increases the ink amount ejected by the second nozzle in addition to the ink amount ejected by the first nozzle, based on the correction value. In this case, the increase rate of the ink amount ejected by the first nozzle is set to be larger than the increase rate of the ink amount ejected by the second nozzle, and in the second correction, in addition to the ink amount ejected by the second nozzle, When the ink amount ejected by the first nozzle is reduced based on the correction value, the reduction rate of the ink amount ejected by the second nozzle is made larger than the reduction rate of the ink amount ejected by the first nozzle. .
That is, in the first embodiment, regarding the specific raster line SRL (first raster line) that has been the target of the correction for increasing the ink amount in step S220, the first nozzle and the first raster line for recording the first raster line The total number of dots ejected by each of the two nozzles increases as compared with the case where the correction in step S220 is not performed. However, the first raster line undergoes the first correction in step S240, so that the ratio of pixels assigned to the first nozzles increases and the ratio of pixels assigned to the second nozzles decreases. That is, in the recording of the first raster line, both the amount of ink ejected by the first nozzle and the amount of ink ejected by the second nozzle may increase, but after the first correction, the first nozzle ejects The rate of increase in the amount of ink ejected exceeds the rate of increase in the amount of ink ejected from the second nozzle. In addition, regarding the specific raster line SRL (second raster line) that has been the target of the correction for reducing the ink amount in step S220, the first nozzle and the second nozzle eject each in order to record this second raster line. The total number of dots decreases as compared with the case where the correction in step S220 is not performed. However, the second raster line undergoes the second correction in step S240, so that the ratio of pixels assigned to the second nozzles decreases and the ratio of pixels assigned to the first nozzles increases. That is, in the recording of the second raster line, both the ink amount ejected by the first nozzle and the ink amount ejected by the second nozzle can be reduced, but the second nozzle ejects by the second correction. The rate of decrease in the amount of ink discharged exceeds the rate of decrease in the amount of ink ejected from the first nozzle.

  In the second embodiment, regarding the specific raster line SRL (first raster line) that has been the target of the correction for increasing the ink amount in step S220, the first nozzle and the second nozzle for recording this first raster line. The total number of dots ejected by each of the dots increases compared to the case where the correction in step S220 is not performed. However, in this first raster line, the number of effective pixels assigned to the first nozzles increases due to the first correction in step S240. That is, in the recording of the first raster line, both the amount of ink ejected by the first nozzle and the amount of ink ejected by the second nozzle may increase, but after the first correction, the first nozzle ejects The rate of increase in the amount of ink ejected exceeds the rate of increase in the amount of ink ejected from the second nozzle. Further, with respect to the specific raster line SRL (second raster line) that has been the target of the correction for reducing the ink amount in step S220, the first nozzle and the second nozzle respectively eject in order to record this second raster line. The total number of dots decreases as compared with the case where the correction in step S220 is not performed. However, the number of effective pixels assigned to the second nozzle is reduced in this second raster line by undergoing the second correction in step S240. That is, in the recording of the second raster line, both the ink amount ejected by the first nozzle and the ink amount ejected by the second nozzle can be reduced, but the second nozzle ejects by the second correction. The rate of decrease in the amount of ink discharged exceeds the rate of decrease in the amount of ink ejected from the first nozzle.

  Further, according to the second embodiment, the effective pixel and the ineffective pixel in the specific raster line SRL are assigned to the leading nozzle and the trailing nozzle, respectively. Therefore, the sum of the usage ratio of the leading nozzle and the usage ratio of the trailing nozzle exceeds 100%. However, since invalid pixels are always dot-off, ignore them and regard the ratio of effective pixels assigned to the preceding nozzle as the actual usage ratio of the preceding nozzle, and set the ratio of effective pixels assigned to subsequent nozzles. It may be regarded as a substantial usage ratio of the trailing nozzles. Based on such a viewpoint, referring to the example of FIG. 12, regarding the specific raster line SRL of the raster number i that has been the target of the correction for increasing the ink amount in step S220, as a result of the dot data correction in step S240, The sum of the usage rate of the leading nozzle “85%” and the usage rate of the trailing nozzle “20%” exceeds 100%. Similarly, as to the specific raster line SRL of the raster number i + 3 that is the target of the correction for increasing the ink amount in step S220, the dot data correction results show that the usage ratio of the preceding nozzle is “20%” and the usage ratio of the following nozzle. The sum of "83%" exceeds 100%.

  That is, in the second embodiment, the sum of the usage ratio of the leading nozzle and the usage ratio of the trailing nozzle exceeds 100% by performing the first correction in step S240 for the first raster line. When the sum of the usage ratios of the leading nozzles and the trailing nozzles exceeds 100%, there is a possibility that a number of dots corresponding to the ink amount further exceeding the ink amount increased by the correction processing in step S220 will be ejected. . Referring to FIG. 12, for example, when a specific raster line SRL with a raster number i is recorded using a preceding nozzle and a following nozzle, some pixels are printed from both the preceding nozzle and the following nozzle. Dots can be ejected.

  As described above, according to the second embodiment, the control unit 11 makes the sum of the usage ratio of the first nozzles and the usage ratio of the second nozzles larger than 100% in the first correction. As a result, the first raster line recorded on the recording medium 30 tends to be thick and dark. Since the first raster line recorded on the recording medium 30 tends to be thick and dark, for example, the first raster line may be generated on the recording medium 30 due to a transport amount error of the recording medium 30 transported by the transport mechanism 21 between passes. It is possible to improve image quality deterioration such as white streaks.

  "First correction for increasing the amount of ink ejected by the first nozzle based on the correction value for the first raster line" or "The amount of ink ejected by the second nozzle for the second raster line is set as the correction value". In the second correction that decreases based on FIG. 11, the correction of the nozzle usage ratio and the correction of the effective pixel and ineffective pixel ratios are performed as described in the first and second embodiments. The correction value for each raster number as shown in (4) was applied as it was. However, in the first correction and the second correction, the correction value for each raster number is not applied as it is, but the correction value for each raster number is changed by, for example, multiplying a predetermined coefficient. The correction value after the change may be used.

6. Other embodiments:
As can be seen from the usage ratio table 16 shown in FIG. 6, the usage ratio of the leading nozzle and the usage ratio of the trailing nozzle may be the same 50% depending on the POL raster position in the POL region. The glossiness of the raster line RL recorded by the leading nozzle and the trailing nozzle having the same usage ratio is particularly low. In consideration of such a situation, the control unit 11 performs the second identification recorded by using the two nozzles 23 (third nozzle and fourth nozzle) having the same usage ratio among the raster lines RL forming the image. A third correction is performed on the raster line to expand the difference between the ink amount ejected by one of the third nozzle and the fourth nozzle and the ink amount ejected by the other nozzle based on the correction value.

  The third nozzle and the fourth nozzle correspond to the preceding nozzle and the succeeding nozzle that are used for recording one raster line RL. However, since the third nozzle and the fourth nozzle have no difference in their usage ratios defined in advance by the usage ratio table 16, the first nozzle and the second nozzle which have a difference in their usage ratios defined in advance. The description is different from the nozzle. Further, the raster line RL recorded by using the third nozzle and the fourth nozzle is the same as the specific raster line SRL in that it is recorded by using the plurality of nozzles 23. However, in order to distinguish it from the specific raster line SRL recorded by using the first nozzle and the second nozzle, the raster line RL recorded by using the third nozzle and the fourth nozzle is called a second specific raster line. .

A specific example of the third correction will be described.
In step S240 of the first embodiment, of the rows of the POL mask 18, the control unit 11 corrects the row at the POL raster position corresponding to the second specific raster line. In this case, based on the correction value corresponding to the raster number of the second specific raster line, the usage ratio of the preceding nozzle, that is, the value “1”, and the usage ratio of the trailing nozzle, that is, the ratio “0” are set. Apply a correction that causes a difference. The control unit 11 applies the POL mask thus corrected, that is, the corrected POL mask 19 to the POL area of the input image. This causes a difference between the number of pixels assigned to the third nozzle and the number of pixels assigned to the fourth nozzle among the pixels forming the second specific raster line included in the POL region, and as a result, the second specific raster line is changed. The difference in the amount of ink ejected by each of the third nozzle and the fourth nozzle for recording increases.

In step S240 of the second embodiment, the control unit 11 performs the correction on the second specific raster line that is the second specific raster line and is one of the dot data KD1 and the dot data KD2. In this case, the effective pixels or the invalid pixels in the target second specific raster line are increased based on the correction value corresponding to the raster number of the target second specific raster line. That is, if the correction value corresponding to the raster number of the target second specific raster line is a correction value that increases the ink amount, the effective pixels in the target second specific raster line are increased based on this correction value. On the other hand, if the correction value corresponding to the raster number of the target second specific raster line is a correction value that reduces the ink amount, the effective pixels in the target second specific raster line are reduced based on this correction value ( Increase the number of invalid pixels). This causes a difference in the number of effective pixels assigned to the third nozzle and the number of effective pixels assigned to the fourth nozzle among the pixels forming the second specific raster line included in the POL region, and as a result, the second specific raster is generated. The difference in the amount of ink ejected by each of the third nozzle and the fourth nozzle for recording the line is enlarged.
By such a third correction, it is possible to suppress gloss unevenness in the recording result of the input image including the second specific raster line.

  Up to now, the description has been given on the premise that the printer 20 is a serial printer as shown in FIGS. However, the printer 20 may be a so-called line printer that performs recording with a long recording head unit in the main scanning direction D1 that intersects the transport direction D2.

  FIG. 13 is a diagram for explaining a recording method that the control unit 11 causes the printer 20, which is a line printer, to execute. Regarding FIG. 13, description will be made focusing on the points different from FIG. The recording head unit is generally formed by rotating the recording head 22 as illustrated in FIG. 2 by 90 ° and connecting a plurality of the recording heads 22 along the main scanning direction D1. No carriage is required in the line printer. Each recording head that constitutes the recording head unit has a nozzle row for each ink color, the nozzle pitch of which is constant in the main scanning direction D1. The nozzle rows 261, 262, 263 shown in FIG. 13 are nozzle rows that belong to different recording heads, and all eject ink of the same color, for example, K ink.

  The individual recording heads that form the recording head unit are arranged such that the end portions of their nozzle rows overlap with other recording heads that are adjacent in the main scanning direction D1. According to the example of FIG. 13, the four nozzles 23 of nozzle numbers # 15 to # 18 of the nozzle row 261 and the four nozzles 23 of nozzle numbers # 1 to # 4 of the nozzle row 262 are arranged in the main scanning direction D1. The nozzle rows 261 and 262 are displaced from each other in the transport direction D2 so as to be at the same position. Similarly, the four nozzles 23 of nozzle numbers # 15 to # 18 of the nozzle row 262 and the four nozzles 23 of nozzle numbers # 1 to # 4 of the nozzle row 263 are at the same position in the main scanning direction D1. Further, the nozzle rows 262 and 263 are arranged so as to be displaced in the transport direction D2. In the longitudinal direction of the recording head unit, that is, along the main scanning direction D1, the relationship between the nozzle rows whose ends overlap each other is repeated.

  Based on the above embodiments, the case where the printer 20 is a line printer will be described. In the line printer, the pass through the serial printer corresponds to recording by each recording head that constitutes the recording head unit. Therefore, the specific raster line SRL is recorded by the portion where the nozzle rows overlap each other as shown in FIG. The leading nozzle and the trailing nozzle are two nozzles 23 having a relationship of recording one specific raster line SRL, and the nozzle 23 relatively located upstream in the transport direction D2 is the leading nozzle and relatively transports. The nozzle 23 located on the downstream side in the direction D2 is a trailing nozzle. When the printer 20 is a serial printer, the line in which the pixels forming the image are arranged corresponding to the main scanning direction D1 is the raster line RL, but when it is a line printer, the pixels correspond to the transport direction D2. The line that is lined up is the raster line RL.

  Of course, when the printer 20 is a line printer, the TP50 shown in FIG. 4 is recorded on the recording medium 30 in a direction in which the lateral direction of each of the density regions A1 to A10 corresponds to the transport direction D2. The POL raster position is a position for each raster line RL in the main scanning direction D1 within the POL area. The raster number is a number for each raster line RL in the main scanning direction D1. As described above, even when the printer 20 is a line printer, uneven density and uneven gloss are suppressed in the recording result of the input image on the recording medium 30. Further, when the printer 20 is a line printer, the image quality deterioration such as white streaks that may occur due to an assembly error between the recording heads is improved by the effect that the first raster line is thick and easily darkened according to the second embodiment. be able to.

  In the recording control process of FIG. 9, the control unit 11 may branch execution / non-execution of step S240 according to the type of the recording medium 30 used by the printer 20. The control unit 11 acquires the type information of the recording medium 30 used by the printer 20 from the user through, for example, the UI screen displayed on the display unit 13. Alternatively, the control unit 11 inquires of the printer 20 about the type of the recording medium 30, and acquires the type information of the recording medium 30 based on the response from the printer 20 to the inquiry. Then, if the type information of the recording medium 30 indicates the first type that is easy to use for recording in which glossiness is important, such as glossy paper or photo-specific paper, the control unit 11 has performed so far. The recording control process including the described step S240 is executed. On the other hand, if the type information of the recording medium 30 indicates a second type that is easy to use for recording in which glossiness is not important, such as plain paper and recycled paper, the control unit 11 omits step S240. Executes recording control processing.

  To omit step S240 in the recording control process means that in the first embodiment, the POL mask 18 is not corrected and the POL mask 18 is simply applied to the POL area. Further, in the second embodiment, the pass (or printhead) dot data KD1 and KD2 generated for each pass or each printhead from the dot data generated by the halftone process is simply corrected for each pass (without correction). Or each recording head). With such a configuration, the present embodiment can be applied to the case where the input image is recorded on the first type recording medium 30.

DESCRIPTION OF SYMBOLS 1 ... System, 10 ... Recording control device, 11 ... Control part, 12 ... Recording control program, 12a ... TP recording control part, 12b ... Correction value calculation part, 12c ... Correction recording control part, 13 ... Display part, 14 ... Operation Reception unit, 15 ... Communication IF, 16 ... Usage ratio table, 17 ... Correction value table, 20 ... Printer, 21 ... Conveying mechanism, 22 ... Recording head, 23 ... Nozzle, 24 ... Carriage, 26 ... Nozzle row, 30 ... Recording Medium, 40 ... Colorimetric device, 50 ... TP

Claims (6)

A recording control device for controlling a recording device that ejects ink from a nozzle to perform recording,
An image in which the ink amount of the raster line is corrected based on a correction value corresponding to the raster line, a control unit for recording the image on the recording device,
The control unit is
A specific raster line recorded by using the first nozzle and the second nozzle having a lower usage ratio than the first nozzle among the raster lines forming the image, and increasing the ink amount based on the correction value. A first correction for increasing the amount of ink ejected from the first nozzle based on the correction value is performed on the first raster line to be corrected,
A second raster line which is the specific raster line and which reduces the ink amount ejected by the second nozzle based on the correction value with respect to a second raster line which is a target of correction for reducing the ink amount based on the correction value; A recording control device, which performs correction. The control unit is
In the first correction, when the amount of ink ejected by the second nozzle is increased based on the correction value in addition to the amount of ink ejected by the first nozzle, an increase rate of the amount of ink ejected by the first nozzle. Greater than the rate of increase in the amount of ink ejected from the second nozzle,
In the second correction, when the amount of ink ejected by the first nozzle is reduced based on the correction value in addition to the amount of ink ejected by the second nozzle, the reduction rate of the amount of ink ejected by the second nozzle is reduced. 2. The recording control apparatus according to claim 1, wherein the recording rate is set to be larger than a reduction rate of the amount of ink ejected from the first nozzle.   The said control part makes the sum of the usage ratio of the said 1st nozzle and the usage ratio of the said 2nd nozzle larger than 100% in the said 1st correction, It is characterized by the above-mentioned. The recording control device described.   The controller controls the second specific raster line recorded by using the third nozzle and the fourth nozzle having the same usage ratio as the third nozzle among the raster lines forming the image, with respect to the second specific raster line. A third correction is performed to expand a difference between an ink amount ejected by one of the three nozzles and the fourth nozzle and an ink amount ejected by the other nozzle based on the correction value. The recording control device according to any one of claims 1 to 3. A recording device for recording by ejecting ink from nozzles,
A control unit for recording an image in which the ink amount of the raster line is corrected based on the correction value corresponding to the raster line,
The control unit is
A specific raster line recorded by using the first nozzle and the second nozzle having a lower usage ratio than the first nozzle among the raster lines forming the image, and increasing the ink amount based on the correction value. A first correction for increasing the amount of ink ejected from the first nozzle based on the correction value is performed on the first raster line to be corrected,
A second raster line which is the specific raster line and which reduces the ink amount ejected by the second nozzle based on the correction value with respect to a second raster line which is a target of correction for reducing the ink amount based on the correction value; A recording device, which performs correction. A recording control method for controlling a recording device that ejects ink from a nozzle to perform recording,
An image in which the ink amount of the raster line is corrected based on a correction value corresponding to the raster line, a control step of recording the image on the recording device,
In the control step,
A specific raster line recorded by using the first nozzle and the second nozzle having a lower usage ratio than the first nozzle among the raster lines forming the image, and increasing the ink amount based on the correction value. A first correction for increasing the amount of ink ejected from the first nozzle based on the correction value is performed on the first raster line to be corrected,
A second raster line which is the specific raster line and which reduces the ink amount ejected by the second nozzle based on the correction value with respect to a second raster line which is a target of correction for reducing the ink amount based on the correction value; A recording control method characterized by executing correction.