JP5838738B2 - Image forming apparatus and program thereof - Google Patents

Description

  The present invention relates to an image forming apparatus and a program thereof.

  Conventionally, as this type of image forming apparatus, an apparatus that can easily perform accurate color matching is known. For example, in Patent Document 1, a color palette chart linked with RGB values is output from an image forming apparatus used for printing, a desired color is selected from an output sample, and RGB values linked to the colors are registered as user colors. Something to be entered in is proposed. In such an image forming apparatus, it is possible to specify the print color output by the apparatus while observing the sample color actually output by the apparatus, and directly specify the actual color actually printed by the apparatus. be able to. Here, for example, when the hue is set to a constant value, the color pallet chart is printed as a list in which patches are arranged in the vertical direction with 10 brightness values in the vertical direction and 10 saturation values in the horizontal direction. .

JP 11-129549 A

  However, in the above-described color palette chart, patches are arranged so that the difference in color information is equally spaced. Therefore, when searching for a patch along the vertical or horizontal direction, the feeling of roughness suddenly increases. (Graininess deteriorates). When performing accurate color matching, it is rare to select a patch with such a rough feeling from the color palette chart, but the size of the patch is the same, so the feeling of roughness is good at a glance. It was not something that could be judged. For this reason, considerable attention is required when performing color matching. In addition to the feeling of roughness, the color difference may change suddenly.

  The main object of the image forming apparatus of the present invention is to prevent an operator from selecting a patch having a large roughness or a patch having a large color difference from a color adjustment chart.

  The present invention adopts the following means in order to achieve the main object described above.

The chart of the present invention is
A first patch;
A second patch having a different color from the first patch;
With
The aspect of the second patch is determined based on the graininess of the first patch and the graininess of the second patch, or the color difference of the second patch from the first patch. Is.

  According to this chart, it is possible to prevent the operator from selecting a patch having a large roughness or a patch having a large difference in color from the chart.

The image forming apparatus of the present invention includes:
An image forming apparatus capable of creating a color adjustment chart in which a plurality of patches filled with one color are arranged,
Printing means for printing on a print medium;
The basic aspect is to arrange the patches so that the difference in color information is a predetermined interval along a predetermined direction starting from a reference patch painted with the reference color, and the granularity index of each patch arranged along the predetermined direction or A printing control unit that changes the basic mode based on a color difference and controls the printing unit to print the color adjustment chart in the changed mode;
It is equipped with.

  In this image forming apparatus, the basic mode is changed based on the granularity index or color difference of each patch arranged along a predetermined direction, and the color adjustment chart is printed in the changed mode. The difference in color information is, for example, the difference between the gradation values of R, G, B of RGB data or the difference of any gradation value of C, M, Y, K of CMYK data. When the patches are arranged in a predetermined direction in the basic mode, even if the patch suddenly increases in roughness when only one patch is viewed along the direction, it may not be noticed. However, since the basic mode is changed in consideration of the difference in the granularity index related to the feeling of roughness, the operator is less likely to select a patch with a feeling of roughness. In addition, when the patches are arranged along a predetermined direction in the basic mode, even if the color difference suddenly increases by one patch when the patches are viewed in order along the direction, it is not noticed. However, since the basic mode is changed in consideration of the color difference related to the color difference, the operator is less likely to select a patch having a large color difference.

  In the image forming apparatus according to the aspect of the invention, when the printing control unit changes the basic mode based on the granularity index or color difference, the arrangement of the patches in the basic mode, the size of each patch, and the decoration of each patch At least one of the above may be changed.

  In the image forming apparatus according to the aspect of the invention, when the printing control unit changes the basic mode based on the graininess index, a total value of a difference in color information and a difference in graininess index between each patch and the reference patch. Unnecessary patches may be removed so that becomes larger along the predetermined direction. In this way, patches with a large difference in granularity index from the reference patch, that is, patches with a large roughness, are excluded from the color adjustment chart, so the operator does not select such patches.

  In the image forming apparatus of the present invention, when changing the basic mode based on the graininess index, the total value of the color information difference and the graininess index difference between each patch and the reference patch is along the predetermined direction. The size of the patch may be reduced for patches that are not large. In this way, a patch having a large difference in granularity index from the reference patch, that is, a patch having a large roughness, is printed small, so that the operator is unlikely to select such a patch.

  In the image forming apparatus according to the aspect of the invention, when the printing control unit changes the basic mode based on the graininess index, a total value of a difference in color information and a difference in graininess index between each patch and the reference patch. The patch decoration may be changed so that the patch is not visually noticeable for a patch that is not large. By doing so, the patch decoration is changed so that a patch having a large difference in granularity index from the reference patch, that is, a patch having a rough feeling is visually inconspicuous, so that the operator is unlikely to select such a patch.

  The program of the present invention is for causing one or a plurality of computers to function as print control means of the above-described image forming apparatus. This program may be recorded on a computer-readable recording medium (for example, hard disk, ROM, FD, CD, DVD, etc.), or from a computer via a transmission medium (communication network such as the Internet or LAN). It may be distributed to another computer, or may be exchanged in any other form. If this program is executed by one computer or shared by a plurality of computers, the same effects as those of the image forming apparatus of the present invention can be obtained.

1 is a configuration diagram illustrating an outline of a configuration of a printing system 1 according to an embodiment. 7 is a flowchart illustrating an example of a color adjustment chart printing routine. Explanatory drawing which shows an example of the chart for color adjustment. The flowchart which shows an example of a granularity parameter | index calculation routine. The arrangement | positioning figure of the patch in a basic aspect. The arrangement | positioning figure of the patch after changing a basic aspect based on a granularity parameter | index. The arrangement | positioning figure of the patch after changing a basic aspect based on a granularity parameter | index. The arrangement | positioning figure of the patch after changing a basic aspect based on a granularity parameter | index. The arrangement | positioning figure of the patch after changing a basic aspect based on a granularity parameter | index.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an outline of the configuration of an image forming apparatus as an embodiment of the present invention, that is, a printing system 1 including a user PC 10 and an inkjet printer 20.

  The user PC 10 is connected to the inkjet printer 20 so as to be able to exchange data, and is configured as a microprocessor centered on the CPU 12, and includes a ROM 14 that stores a processing program, a RAM 16 that temporarily stores data, and an inkjet printer. And an HDD 18 in which 20 printer drivers 18a and the like are installed. The printer driver 18a receives image data composed of RGB data stored in the HDD 18 or the like, converts it into CMYK data, and forms halftones formed by dispersing ink dots to express the gradation values of the CMYK data. A program is included that executes processing, rearranges the halftone-processed data in order of data to be transferred to the inkjet printer 20, and transfers the print data to the inkjet printer 20. In addition, the printer driver 18a includes a program for creating a color adjustment chart and outputting the chart to the inkjet printer 20, which will be described in detail later.

  The ink jet printer 20 includes a paper feed mechanism 41 that transports the paper P in the sub-scanning direction (the direction from the back to the front in FIG. 1), and the main scanning direction with respect to the paper P that is transported onto the platen 46 by the paper feed mechanism 41. A printer mechanism 21 that performs printing by ejecting ink droplets from nozzles formed on the print head 24 with movement in the left and right directions in FIG. 1 and a controller 60 that controls the entire apparatus are provided. A capping device 50 for sealing the nozzle surface of the print head 24 is installed at one end of the platen 46 in the main scanning direction (right end in FIG. 1), and at the other end of the platen 46 in the main scanning direction (left end in FIG. 1). In order to prevent nozzle clogging, a flushing area 48 for performing flushing for ejecting ink droplets from the nozzles of the print head 24 periodically is provided.

  The printer mechanism 21 includes a carriage 22 that can reciprocate in the main scanning direction while being guided by a carriage guide 28, a carriage motor 34 and a driven roller 35 that are respectively installed on one end side and the other end side of the carriage guide 28, and a carriage motor. 34 and a follower roller 35, and a carriage belt 32 mounted on the carriage 22, and cyan (C), magenta (M), yellow (with pigment particles dispersed in water as a solvent mounted on the carriage 22) Y) and black (K) inks that can be stored and exchanged independently for each color, and a plurality of ink cartridges that pressurize each ink supplied from the ink cartridge 26 and eject ink droplets. And a print head 24 in which nozzles are formed. The carriage 22 is reciprocated in the main scanning direction by driving the carriage belt 32 by a carriage motor 34. A carriage position sensor 36 for detecting the position of the carriage 22 in the main scanning direction is attached to the back side of the carriage 22. The carriage position sensor 36 is a linear optical scale 36a disposed on the frame 58 along the carriage guide 28. The carriage position sensor 36 is attached to the back surface of the carriage 22 so as to oppose the optical scale 36a, and optically reads the optical scale 36a. And a sensor 36b.

  The paper feed mechanism 41 includes a transport roller 42 that transports the paper P onto the platen 46, and a transport motor 44 that rotationally drives the transport roller 42. The transport motor 44 is provided with a rotary encoder 49 that detects the amount of rotation on its rotation shaft, and is driven and controlled based on the amount of rotation from the rotary encoder 49. Although not shown, the rotary encoder 49 includes a rotary scale that is graduated at predetermined rotation angle intervals and a rotary scale sensor that reads the scale of the rotary scale.

  The capping device 50 prevents the ink in the nozzles from drying or seals the nozzle surface by sealing the nozzle surface while the print head 24 is moved to a position facing the capping device 50 (so-called home position). The print head 24 is cleaned by sucking the ink in the nozzles in a stopped state. The capping device 50 is attached to a tube (not shown) connected to the bottom of the cap 51, in addition to a substantially rectangular parallelepiped cap 51 having an upper opening for sealing the nozzle surface of the print head 24. And a suction pump (not shown). When cleaning the print head 24, the capping device 50 drives the suction pump while the nozzle surface of the print head 24 is sealed by the cap 51, so that the nozzle surface of the print head 24 and the cap 51 The formed internal space is set to a negative pressure, and ink in the nozzle is forcibly sucked.

  The controller 60 is configured as a microprocessor centered on a CPU (not shown), and has a function of executing various programs and storing data. The controller 60 receives the position of the carriage 22 from the carriage position sensor 36 and the rotation amount of the transport roller 42 from the rotary encoder 49. The controller 60 outputs a drive signal to the print head 24 and a transport motor 44. A drive signal, a drive signal to the carriage motor 34, a drive signal to the suction pump, and the like are output. Further, the controller 60 receives a print instruction and print data from the user PC 10. The controller 60 is provided with a print buffer area. When print data is received from the user PC 10, the received print data is stored in the print buffer area.

  Next, an operation of the user PC 10 of the printing system 1 of the present embodiment configured as described above, particularly an operation when creating a color adjustment chart will be described. FIG. 2 is a flowchart showing an example of a color adjustment chart creation routine executed by the CPU 12 of the user PC 10. This routine is started when the user inputs a color adjustment chart creation instruction by operating a keyboard or a mouse (not shown). The color adjustment chart is a color chart used by the user to make his desired color coincide with the color printed on the paper by the inkjet printer 20.

  In this embodiment, as shown in FIG. 3, this color adjustment chart has a total of 3 blocks in which a total of 9 patches of 3 × 3 are arranged (the number of patches is 27 in total of 3 × 3 × 3). Shall have. The three blocks are arranged in the horizontal direction. In the leftmost block, a color patch (reference patch) preset by the user is arranged at the upper left, and the blue (B) value of the RGB data increases from there to the right, and the RGB data downward. A total of nine patches of 3 × 3 in length and width are arranged so that the value of green (G) of the image becomes larger. In the central block, a patch having an R value that is 1 larger than the RGB data of the reference patch and having the same G and B values is arranged at the upper left, and from there the blue (B) value of the RGB data in the right direction. A total of nine patches of 3 × 3 in length and width are arranged so that the green (G) value of the RGB data increases in the downward direction. In the rightmost block, a patch having an R value that is 2 larger than the RGB data of the reference patch and having the same G and B values is arranged at the upper left, and from there the blue (B) value of the RGB data in the right direction. A total of nine patches of 3 × 3 in length and width are arranged so that the green (G) value of the RGB data increases in the downward direction.

  When the color adjustment chart creation routine of FIG. 2 is started, the CPU 12 first inputs RGB data relating to the reference color, and sets the RGB data as the reference color of the current color adjustment chart (step S100). Specifically, a screen for prompting input of RGB data related to the reference color is displayed on a display (not shown), waits for the user to input the RGB data, and the RGB data is used as the reference color of the current color adjustment chart. Set. Here, it is assumed that the user knows RGB data close to his desired color.

  Subsequently, the CPU 12 sets the number of patches to be generated (step S102). As described above, the color adjustment chart has 3 blocks each consisting of a total of 9 patches of 3 × 3, and thus has a total of 27 patches. In order to create a color adjustment chart by thinning out, more than 27 patches are required. For this reason, in the present embodiment, a total of 216 of 6 × 6 × 6 is set as the number of patches to be generated with a margin.

  Subsequently, the CPU 12 calculates a granularity index for all the patches to be generated (step S104). As described above, there are 216 patches to be generated. In the RGB data, if R, G, and B values of the RGB data of the reference color are r, g, and b, R is a value r to (r + 5), G is a value g to (g + 5), and B is a value. It is a combination of b to (b + 5).

  The CPU 12 calculates the granularity index according to the granularity index calculation routine of FIG. First, an image of a target patch is acquired (step S200). In the present embodiment, it is assumed that an image of 1 inch × 1 inch is acquired, the resolution is 360 dpi, the number of pixels is 360 × 360 pixels, and the image data is RGB data. It is assumed that each of R, G, and B data is represented by any gradation value from 0 to 255.

  Next, the CPU 12 converts the image data, which is RGB data, into CMYK data, and performs color separation for each CMYK color (step S202). Conversion to CMYK data is performed using a color conversion LUT (lookup table) in which a combination of R, G, and B and a combination of C, M, Y, and K to be expressed by the inkjet printer 20 are associated with each other. . Since such a color conversion LUT is well known, detailed description thereof is omitted. Each data of C, M, Y, K is assumed to be represented by any gradation value of 0-255.

  Next, the CPU 12 performs halftone processing for each of the C, M, Y, and K data after color separation (step S204). The halftone process is a process of converting to a gradation value that can be expressed by the inkjet printer 20 in accordance with the gradation value for each color. In the present embodiment, the gradation values that can be expressed by the inkjet printer 20 are four values: small dots, medium dots, large dots, and no dots. In the present embodiment, halftone processing is performed using a known dither method. For example, if the cyan gradation value is C1, any one of four values for each pixel using a dither matrix for each predetermined dot size so that the cyan gradation value becomes C1 for the entire patch. Is set. The dot size can be changed by adjusting a drive signal applied to the piezoelectric element corresponding to the nozzle of the print head 24 of the inkjet printer 20. In addition to the dither method, a known error diffusion method may be applied.

  Next, the CPU 12 calculates the dot occurrence rate of each color of C, M, Y, and K after the halftone process (step S206). Here, the number of dots of each color is calculated, a value obtained by dividing the number of dots of each color by the total number of pixels (360 × 360 pixels) is calculated as a dot occurrence rate, and the dot occurrence rate of each color is expressed by a vector. . For example, if the number of cyan and black dots is 36 and the number of magenta and yellow dots is zero, 36 / (360 × 360) = 0.277e−3, and each color is multiplied by 10,000 (C , M, Y, K) = (2.7, 0, 0, 2.7).

  Next, the CPU 12 calculates the granularity index of the patch targeted this time based on the dot occurrence rate of each color (step S208). Here, the granularity index is calculated by applying the CMYK vector value to the following equation. Since Y is an inconspicuous color, the coefficient γ is smaller than the other coefficients, and since K is an easily noticeable color, the coefficient θ is larger than the other coefficients. Specifically, α = β = 0.5, γ = 0.1, and θ = 1.0. It can be determined that the larger the value of the granularity index, the worse the granularity (that is, there is a feeling of roughness).

Granularity index = α × C dot generation rate + β × M dot generation rate
+ Γ × Y dot generation rate + θ × K dot generation rate Note that the granularity index is not limited to the above formula. For example, RMS (Root Mean Square) or WS (Wiener Spectrum), which are known granularity indexes, can be used. RMS is an index representing the degree of density variation, and the density distribution of the profile obtained by measuring the density of a solid image of substantially uniform density obtained by printing image data having a uniform signal value. Standard deviation. WS is a spatial frequency characteristic of granular noise applied to an image, and a density profile of an image having a substantially uniform density is obtained, and a value obtained by performing Fourier transform on the profile from which the trend is removed is 2 Expressed as a power.

  Thereafter, the CPU 12 determines whether or not the granularity index has been calculated for all of the patches to be generated (step S210), and if there are any remaining patches, the target is selected from the remaining patches. A patch is selected, and the processes after step S200 are executed again. On the other hand, if the calculation of the granularity index has been completed for all the patches to be generated in step S210, this routine ends.

  After the end of the granularity index calculation routine, the process returns to the flowchart of FIG. 2, and the CPU 12 arranges the patch at each position of the color adjustment chart based on the color information of the patch and the granularity index (step S106). Specifically, each patch is arranged along the predetermined direction, with the basic mode of arranging the patches so that the difference in gradation value is 1 along the predetermined direction starting from the reference patch filled with the reference color. The basic mode is changed based on the granularity index between the reference patch and the reference patch.

  In this embodiment, the arrangement of patches shown in FIG. FIG. 5 shows the basic mode of the leftmost block in the color adjustment chart of FIG. 3, but the same applies to the other blocks. Below, a basic aspect is demonstrated. Here, the position of each patch is represented by x and y coordinates, the reference position is (x, y) = (0, 0), and the first position to the right of the reference position is (x, y). = (1, 0), the second position in the right direction is represented as (x, y) = (2, 0). In the basic mode, a first patch (reference patch) composed of a reference color is arranged at (x, y) = (0, 0), and RGB of the first patch is set at (x, y) = (1, 0). A second patch having the same R and G gradation values and a larger B gradation value by 1 than the data is arranged, and (x, y) = (2, 0) is compared with the RGB data of the first patch. A third patch having the same R and G tone values and a large B tone value of 2 is arranged. Although not used in the basic mode, the fourth to sixth patches have the same R and G tone values and the B tone values that are 3, 4 and 5 larger than the first patch, respectively. These are preliminarily created in preparation for changing the basic mode. The position of the second row of the basic mode is (x, y) = (0, −1), (1, −1), (2, −1), but (x, y) = (0, The patch arranged in -1) is a patch having the same R and B tone values and a larger G tone value than the RGB data of the first patch, (x, y) = (1, -1) The patch arranged in is a patch having the same R gradation value and one G and B gradation values each larger than the RGB data of the first patch, and is arranged at (x, y) = (2, −1). The patch to be applied is a patch having the same R gradation value, a G gradation value of 1 and a B gradation value of 2 larger than the RGB data of the first patch. The position of the third row in the basic mode is (x, y) = (0, −2), (1, −2), (2, −2), but (x, y) = (0, −2). ) Is a patch having the same R and B gradation values and a larger G gradation value by 2 than the RGB data of the first patch, and is arranged at (x, y) = (1, -2). The patch to be applied is a patch having the same R gradation value, two G gradation values, and one B gradation value one larger than the RGB data of the first patch, (x, y) = (2, −2 ) Is a patch having the same R gradation value and two G and B gradation values larger than the RGB data of the first patch. Although not used in the second and third lines of the basic mode, a preliminary patch is created as in the first line.

  In step S106, in changing the basic mode based on the granularity index of the patch, the total value of the color information difference and the granularity index difference between each patch and the first patch is large along the right direction, and The arrangement of the patches in the basic mode is changed by deleting unnecessary patches so as to increase in the downward direction. For example, it is assumed that the granularity index of the three patches arranged in the first row of the basic mode is 1.0 for the first patch, 2.5 for the second patch, and 1.25 for the third patch. Then, the second patch has a gradation value difference of 1 and a granularity index difference of 1.5, and the total of both is 2.5. The third patch has a tone value difference of 2 and a graininess index difference of 0.25 from the first patch, and the sum of both is 2.25. In this case, since the total value is not arranged so as to increase in the right direction, the second patch is deleted. Then, the third patch is arranged at the position (x, y) = (1, 0), and the fourth patch is arranged at the position (x, y) = (2, 0). And about the three patches newly arranged in the 1st line of the basic aspect, it changes so that the total value of the difference of a color information and the difference of a granularity index may become large along a right direction again. The same procedure is repeated for patches arranged in the vertical direction, and the basic mode is changed as necessary. FIG. 6 shows a patch layout after the basic mode is changed in this way.

  Next, after arranging all the patches, the CPU 12 creates print data for the color adjustment chart and outputs it to the inkjet printer 20 (step S108). The color adjustment chart output from the ink jet printer 20 excludes patches in which the graininess suddenly deteriorates when the patches arranged in the horizontal direction or the vertical direction are viewed in each block. Become.

  Here, the correspondence between the components of the present embodiment and the components of the present invention will be clarified. The image forming apparatus of the present embodiment corresponds to the printing system 1 of the present embodiment, the ink jet printer 20 corresponds to a printing unit, and the printer driver 18a of the user PC 10 corresponds to a printing control unit. Further, R, G, and B gradation values of RGB data correspond to color information.

  According to the printing system 1 of the present embodiment described above, the basic mode is changed based on the granularity index between the patches arranged in the horizontal direction (or the vertical direction) and the reference patch, and the color is changed in the changed mode. Since the adjustment chart is printed, the basic mode is changed in consideration of the difference in the granularity index related to the rough feeling, and the operator is less likely to select a patch having a large rough feeling. In particular, since unnecessary patches are deleted so that the total value of the color information difference and the granularity index difference between each patch and the reference patch increases along the horizontal direction (or vertical direction), the granularity with the reference patch Patches with a large difference in sex index, that is, patches with a large roughness, are excluded from the color adjustment chart, and the operator does not select such patches.

  Here, the sudden deterioration in graininess can be attributed to the fact that the arrangement of dots after halftone processing is biased, etc., but this is thought to be due to the way the color conversion LUT or dither matrix is set. It is done. However, even if various settings of the color conversion LUT and dither matrix are examined, it is difficult to prevent the graininess from abruptly deteriorating. For this reason, it is meaningful to change the basic mode based on the granularity index of the patch as in this embodiment.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  For example, in the above-described embodiment, unnecessary patches are deleted so that the total value of the color information difference and the granularity index difference between each patch and the reference patch increases along the horizontal direction (or vertical direction). The size of such unnecessary patches may be reduced. For example, in step S106, the granularity index value is 1.0 for the first patch, 2.5 for the second patch, and 1.25 for the third patch, so the granularity index between the first patch and the second patch. Of the first patch and the granularity index ratio of the first patch to the third patch, that is, 1 / 1.25 = 0.8. The size of the patch may be changed to 0.4 times that of the first patch, and the size of the third patch may be changed to 0.8 times that of the first patch. FIG. 7 shows a patch layout at this time. As a result, patches with good graininess are large and patches with poor graininess are small, so that it is difficult for the operator to select patches with poor graininess, and it becomes easier to find patches with good graininess. In this case, the size may be calculated in consideration of not only the horizontal direction but also the vertical direction. For example, when the second patch is twice the horizontal direction and 2.5 times the vertical direction with respect to the first patch, the size of the second patch is (2 + 2.5) /2.0=2 of the first patch. It is good also as 25 times. The reason that the denominator is 2.0 is that the horizontal length of the first patch is 1.0 and the vertical length is 1.0, and the sum is 2.0. Moreover, after thinning out unnecessary patches as in the above-described embodiment, the patch size may be changed according to the ratio of the granularity index for the patches employed in the color adjustment chart.

  Further, instead of thinning out unnecessary patches, decoration may be performed so that unnecessary patches are not noticeable. For example, in step S106, the granularity index value is 1.0 for the first patch, 2.5 for the second patch, and 1.25 for the third patch. The outer frame of the three patches may be made thicker next, and the outer frame of the second patch may be made the thinnest. An example of the patch layout at this time is shown in FIG. Alternatively, the outer frame of the first and third patches is blue (the operator is informed in advance as a color indicating that the graininess is good), and the outer frame of the second patch is red (the color indicating that the graininess is poor) The operator may be notified in advance). An example of the patch layout at this time is shown in FIG. In any case, it becomes difficult for the operator to select a patch with poor graininess, and it becomes easier to find a patch with good graininess.

In the above-described embodiment, the basic mode is changed based on the granularity index of the patches arranged along the predetermined direction, but a color difference may be used instead of the granularity index. For example, the RGB data of each patch is converted into Lab data via a color space called XYZ tristimulus values, the color difference is calculated as (a ² + b ² + L ² ) ^1/2 , and the arrangement of the basic modes is not changed. In addition, the larger the color difference with respect to the reference patch, the smaller the patch size may be, or the patch may have an inconspicuous decoration. Alternatively, the patches may be thinned out so that the total value of the difference between the granularity index and the color difference between each patch and the reference patch increases along a predetermined direction (for example, rightward or downward).

  In the above-described embodiment, the print control unit is the CPU 12 of the user PC 10, but may be the controller 60 of the inkjet printer 20. In this case, the inkjet printer 20 corresponds to the image forming apparatus of the present invention, and a program similar to the printer driver 18a is stored in the internal memory (ROM or the like) of the controller 60. Even in this case, the same effect as the above-described embodiment can be obtained.

  In the above-described embodiment, the print head 24 employs a system in which a voltage is applied to the piezoelectric element to deform the piezoelectric element and pressurize the ink. However, the heating resistor (for example, a heater) has a voltage applied thereto. It is also possible to adopt a method in which the ink is pressurized by bubbles generated by heating the ink by applying.

  In the above-described embodiment, the ink jet printer 20 is employed as the printing unit. However, the ink jet printer 20 may be employed in a laser printer using a toner cartridge or another type of printer.

1 printing system, 10 user PC, 12 CPU, 14 ROM, 16 RAM, 18 HDD, 18a printer driver, 20 inkjet printer, 21 printer mechanism, 22 carriage, 24 print head, 26 ink cartridge, 28 carriage guide, 32 carriage belt , 34 Carriage motor, 35 Drive roller, 36 Carriage position sensor, 36a Optical scale, 36b Optical sensor, 41 Paper feed mechanism, 42 Transport roller, 44 Transport motor, 46 Platen, 48 Flushing area, 49 Rotary encoder, 50 Capping device, 51 caps, 58 frames, 60 controllers

Claims (7)

An image forming apparatus capable of creating a color adjustment chart in which a plurality of patches filled with one color are arranged,
Printing means for printing on a print medium;
The basic aspect is to arrange the patches so that the difference in color information is a predetermined interval along a predetermined direction starting from a reference patch painted with the reference color, and the granularity index of each patch arranged along the predetermined direction or A printing control unit that changes the basic mode based on a color difference and controls the printing unit to print the color adjustment chart in the changed mode;
Equipped with a,
In changing the basic mode based on the graininess index, the print control unit increases a total value of color information difference and graininess index difference between each patch and the reference patch along the predetermined direction. Remove unnecessary patches so that
Image forming apparatus. When changing the basic mode based on the graininess index or the color difference, the print control unit changes at least one of the arrangement of the patches, the size of each patch, and the decoration of each patch in the basic mode. ,
The image forming apparatus according to claim 1 .   An image forming apparatus capable of creating a color adjustment chart in which a plurality of patches filled with one color are arranged,
  Printing means for printing on a print medium;
  The basic aspect is to arrange the patches so that the difference in color information is a predetermined interval along a predetermined direction starting from a reference patch painted with the reference color, and the granularity index of each patch arranged along the predetermined direction or A printing control unit that changes the basic mode based on a color difference and controls the printing unit to print the color adjustment chart in the changed mode;
  With
  In changing the basic mode based on the graininess index, the print control unit increases a total value of color information difference and graininess index difference between each patch and the reference patch along the predetermined direction. Determine whether or not the patch is not large, and reduce the size of the patch.
Image forming apparatus.   When changing the basic mode based on the graininess index or the color difference, the print control unit changes at least one of the arrangement of the patches, the size of each patch, and the decoration of each patch in the basic mode. ,
  The image forming apparatus according to claim 3.   An image forming apparatus capable of creating a color adjustment chart in which a plurality of patches filled with one color are arranged,
  Printing means for printing on a print medium;
  The basic aspect is to arrange the patches so that the difference in color information is a predetermined interval along a predetermined direction starting from a reference patch painted with the reference color, and the granularity index of each patch arranged along the predetermined direction or A printing control unit that changes the basic mode based on a color difference and controls the printing unit to print the color adjustment chart in the changed mode;
  With
  In changing the basic mode based on the graininess index, the print control unit increases a total value of color information difference and graininess index difference between each patch and the reference patch along the predetermined direction. Change the patch decoration so that the patch that is not large is visually inconspicuous,
  Image forming apparatus.   When changing the basic mode based on the graininess index or the color difference, the print control unit changes at least one of the arrangement of the patches, the size of each patch, and the decoration of each patch in the basic mode. ,
  The image forming apparatus according to claim 5. A program for causing one or a plurality of computers to function as the print control unit of the image forming apparatus according to any one of claims 1 to 6.

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