JP2012198177A - Print control device, printer, print control method, and print control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a color measurement result with the color measurement unevenness of a color measurement device reduced.SOLUTION: A print control device performs: causing a printing part U10 to print a test chart TC1 including a predetermined-density reference patch PS1 arranged in an x-direction and a measuring patch PA1 disposed at a position in a y-direction from the reference patch PS1; generating correction data (color measurement result correction table TA1) for reducing variation in a color measurement result in the x-direction on the basis of a measurement result R(λ,x) of the reference patch PS1 obtained by color-measuring the test chart TC1 with a color measurement device 30; and correcting, in accordance with the correction data (TA1), a color-measurement result R(λ,x) of the measuring patch PA1 obtained by color-measuring the test chart TC1 with the color measurement device 30.

Description

  The present invention relates to a technique for printing each patch for a colorimetric device that performs colorimetry on each patch arranged in the x direction and the y direction, and obtaining a colorimetric result of each patch.

  The colorimetric device has a predetermined colorimetric area in which a test chart (also called a test pattern) in which a plurality of patches are arranged in two dimensions is arranged, and each of the plurality of patches (also called color charts) is automatically Some have colorimetry. As this type of color measuring device, for example, a color measuring sensor capable of reciprocating in a predetermined x direction (scanning direction) and a print medium on which a test chart is formed are moved in a y direction (feeding direction) orthogonal to the x direction. There is an automatic colorimetric device that includes a feeding means for causing the printing medium and a white backing material that is used as an underlay for the printing medium. This automatic color measurement device repeats the measurement of a plurality of patches in the x direction by moving the color measurement sensor by feeding the print medium by one patch in the y direction by the feeding means. As a result, a color measurement result is obtained for each of the plurality of patches arranged two-dimensionally and used for calibration of the printing apparatus.

JP 2009-219090 A

  It has been found that there is color measurement unevenness (spots) according to the position in the x direction for the automatic color measurement device described above. On the other hand, it is also required to perform calibration or the like using a colorimetric device having such colorimetric unevenness.

  Note that, as described in paragraph 0005, the calibration system described in Patent Document 1 suppresses the effects of periodic density unevenness and accidental density unevenness due to rotation unevenness of the photoconductor and the intermediate transfer member. Is an issue. Therefore, the technique described in Patent Document 1 does not belong to the technical field of reducing the colorimetric unevenness of the colorimetric device.

  In view of the above, one of the objects of the present invention is to obtain a color measurement result with reduced color measurement unevenness of the color measurement device.

Means for solving the problems and their actions and effects

In order to achieve one of the above objects, the present invention causes a printing unit to print each patch for a color measurement device that measures colors of patches arranged in the x and y directions intersecting each other, and each patch. A print control device for obtaining a colorimetric result of
A test chart printing control unit that causes the printing unit to print a test chart having a reference patch having a constant density arranged in the x direction and a measurement patch provided at a position in the y direction from the reference patch;
Correction data generating means for generating correction data for reducing variations in the color measurement results in the x direction based on the color measurement results of the reference patch obtained by measuring the test chart with the color measurement device;
One of the aspects is a color measurement result correcting unit that corrects the color measurement result of the measurement patch obtained by measuring the test chart with the color measurement device according to the correction data.

  In addition, the printing apparatus according to the present invention has an aspect in which the test chart is printed by the printing unit under the control of the print control apparatus.

  In this test chart, reference patches having a constant density are arranged in the x direction. Correction data for reducing variations in the color measurement results in the x direction is generated from the color measurement results of these reference patches. The color measurement result of the measurement patch provided at the position in the y direction from the reference patch is corrected according to the correction data. As a result, the colorimetric result of the measurement patch is reduced in variation in the colorimetric result in the x direction. Therefore, this aspect can obtain a color measurement result with reduced color measurement unevenness (spots) of the color measurement device.

Here, the printing control apparatus can be provided in a printing apparatus having a printing unit, an external apparatus connected to the printing apparatus, a color measurement apparatus, an external apparatus connected to the color measurement apparatus, etc. It can also be provided over a plurality of devices.
The patch means an area that is a unit of colorimetry. In the reference patches arranged in the x direction, the colorimetric unit areas may be separated from each other, or the unit areas may be connected in a band shape. Therefore, the reference patches in which the color measurement unit areas are connected in a band shape are also included in the reference patches arranged in the x direction.
The reference patch may be provided over a plurality of lines such as for each color of ink, or only one color may be provided. Further, the reference patch includes not only a patch formed of a fluid to be ejected such as ink but also a patch composed of a portion where nothing is printed on a printing medium.

The above colorimetric results are spectral reflectances, CIE L ^* a ^* b ^* color space values L ^* , a ^* , b ^* , CIE L ^* u ^* v ^* colors specified by the International Commission on Illumination (CIE). Space values L ^* , u ^* , v ^* , CIE XYZ color space values X, Y, Z, RGB color space values R, G, B, secondary values obtained from these values, Etc. Hereinafter, the description of “ ^* ” is omitted.
For example, the correction data generation means generates correction data for reducing the variation in spectral reflectance in the x direction based on the spectral reflectance of the reference patch, and the colorimetric result correction means uses the spectral reflectance of the measurement patch. Is corrected according to the correction data, it is possible to obtain a color measurement result in which color measurement unevenness of the color measurement device is more preferably reduced.

  The test chart printing control unit may cause the printing unit to print the test chart in which second reference patches having a certain density arranged in the y direction are provided in the x direction from the measurement patch. . The correction data generation means is a second unit for reducing variation in color measurement results in the y direction based on the color measurement results of the second reference patch obtained by measuring the test chart with the color measurement device. Correction data may be generated. The color measurement result correcting unit may correct a color measurement result of the measurement patch obtained by measuring the test chart with the color measuring device according to the second correction data. In this aspect, a color measurement result in which color measurement unevenness in the y direction is reduced can be obtained.

  The test chart has different reference patches at different positions in the y direction, and a portion of the reference patches that is not read on the print medium by the reference patch first read by the colorimetric device is printed in the x direction. It may be a side-by-side patch. In this aspect, when performing color measurement while printing a test chart on a printing device equipped with a color measurement device, the time until the start of color measurement is shortened compared to the case of printing a reference patch that is read first. Can do.

  The colorimetric device includes a white backing material disposed on the back side of the test chart and a colorimetric sensor disposed on the front side of the test chart, and the correction data generating means includes the test chart formed on mat paper. Correction data for reducing variations in the color measurement results in the x direction is generated on the basis of the color measurement results of the reference patch obtained by color measurement by the color measurement device, and the color measurement result correction unit is configured to perform the mat measurement. The color measurement result of the measurement patch obtained by measuring the color of a test chart formed on paper with the color measurement device may be corrected according to the correction data. This aspect can more preferably reduce the colorimetric unevenness of the colorimetric device.

  The aspect described above includes a printing apparatus including the above-described printing control apparatus, a printing system including the above-described printing control apparatus, for example, a printing control method and a printing method including processes such as a test chart printing control process, a correction data generation process, and a colorimetry result correction process. The present invention can be applied to a test chart, a print medium on which a test chart is formed, a print control program for causing a computer to realize the functions of the print control apparatus, a print program, a computer-readable medium on which these programs are recorded, and the like.

The figure which illustrates typically the structure of the printing control apparatus U0. (A) And (b) is a figure which illustrates typically test chart TC1 formed in printing medium PM1. The figure which illustrates typically test chart TC1 which has 2nd standard patch PS2. (A)-(c) is a block diagram which illustrates typically the outline of the composition of a printing system. 2 is a block diagram schematically illustrating the configuration of a host device 10 and a printing device 20. FIG. FIG. 4A is a perspective view illustrating a main part of the color measuring device 30; FIG. FIG. 4A is a front view illustrating a main part of the color measurement device 30; FIG. 4B is a diagram illustrating an average value of spectral reflectances with respect to a position x in the main scanning direction; (A) And (b) is a figure which illustrates typically the structure of patch arrangement | positioning table TP1. 6 is a flowchart illustrating color measurement result acquisition processing performed by the print control apparatus U0. 5A is a flowchart illustrating color correction table generation processing performed by the print control apparatus U0, and FIG. 5B is a flowchart illustrating print control processing performed by the print control apparatus U0.

(1) Outline of color measurement result acquisition method:
First, an outline of a color measurement result acquisition method according to an aspect of the present invention will be described with reference to FIG.
The print control device U0 causes the printing unit U10 to print each patch for the color measurement device 30 that measures the respective patches arranged in the x direction and the y direction that intersect with each other, and obtains a color measurement result of each patch. Is. The patch is also called a color chart, and means a region that is a unit of color measurement by the color measurement device 30. The target color measurement device 30 measures the color of each patch provided in the test chart TC1 arranged in the color measurement area AC1. The test chart TC1 is also called a test pattern.

The print control device U0 can be configured by means U1 to U3 shown in FIG. 1, for example.
The test chart printing control unit U1 causes the printing unit U10 to print the test chart TC1 having the reference patch PS1 and the measurement patch PA1. The reference patch PS1 is used to correct the color measurement result obtained by the color measurement device 30. The measurement patch PA1 is used for calibration that compensates for color misregistration of the printing unit U10.

  FIG. 2A schematically shows an example of a test chart TC1 formed on the front side PM1a of the print medium PM1. On the test chart TC1, reference patches PS1 or measurement patches PA1 are arranged in the x and y directions orthogonal to each other.

The reference patches PS1 are arranged in the x direction with a constant density. The test chart TC1 has different reference patches PS1 at different positions in the y direction in the upper region AP1. At the position “1” in the y direction, a white paper (W) reference patch PS1w composed of a portion where nothing is printed on the print medium PM1 is arranged at positions “1” to “8” in the x direction. Has been. At positions “2”, “3”, “4”, and “5” in the y direction, the inks were formed with cyan (C), magenta (M), yellow (Y), and black (K) inks, respectively. Reference patches PS1c, PS1m, PS1y, and PS1k are arranged in the x direction. The reference patches PS1w, PS1c, PS1m, PS1y, and PS1k at the x positions “1” to “8” are patches having the same recording density.
Of these reference patches PS1w, PS1c, PS1m, PS1y, PS1k, the colorimetric device 30 first reads the reference patch PS1w in which portions not printed on the print medium PM1 are arranged in the x direction. . The test chart TC1 having such an arrangement is a case where the reference patch PS1 that is read first is printed when the color measurement is performed while the test chart TC1 is printed by a printing apparatus with a colorimetric device as shown in FIG. Compared to, the time required to start color measurement can be shortened.

The measurement patch PA1 is provided at a position in the y direction from the reference patch PS1. The test chart TC1 includes a plurality of measurement patches PA1 arranged in the x direction and the y direction in a region AP3 below the reference patch region AP1. The arrangement of the measurement patch PA1 in the measurement patch area AP3 is arbitrary and is not particularly limited.
The target PA2 and the like may be formed outside the areas AP1 and AP3 with ink or the like. The target PA2 shown in FIG. 2A is printed at each of the y positions “1” to “15” before the position “1” in the x direction.

  The patches arranged on the test chart TC1 may be separated from each other as shown in FIG. 2A, or adjacent to each other as shown in FIG. 2B. In the reference patches PS1w, PS1c, PS1m, PS1y, and PS1k shown in FIG. 2B, the colorimetric unit areas are connected in a band shape. This case is also included in that the reference patches are arranged in the x direction.

  Further, as shown in the test chart TC1 shown in FIG. 3, a second reference patch PS2 having a constant density arranged in the y direction may be provided at a position in the x direction from the measurement patch PA1. The test chart TC1 has different second reference patches PS2 at different positions in the x direction in the left and right area AP2. At the position “1” in the x direction, the paper white (W) reference patch (w) composed of a portion where nothing is printed on the print medium PM1 is positioned at positions “6” to “15” in the y direction. Is arranged. Reference patches (c, m, y, k) formed of C, M, Y, K inks are respectively located at positions “2”, “3”, “12”, “13” in the x direction. They are arranged in the y direction. The reference patches (w, c, m, y, k) at the y positions “6” to “15” are patches having the same recording density.

When the test patch TC1 having the reference patch PS1, the measurement patch PA1, and the second reference patch PS2 as necessary is printed, the correction data generation unit U2 displays the color measurement result of the reference patch PS1 as shown in FIG. Based on this, a colorimetric result correction table (correction data) TA1 is generated. The color measurement result correction table TA1 is an information table for reducing variations in color measurement results in the x direction.
Here, the color measurement result of the reference patch PS1 obtained by arranging the test chart TC1 in the color measurement region AC1 of the color measurement device 30 and performing the color measurement by the color measurement device 30 is, for example, the spectral reflectance R (λ, x). To do. Since the reference patches PS1 are arranged in the x direction, a spectral reflectance R (λ) is obtained for each position in the x direction. Further, the spectral reflectance is obtained for each frequency λ which is an interval of Δλ (nm) from the minimum wavelength λmin (nm) detected by the colorimetric device 30 to the maximum wavelength λmax (nm). For example, if λmin = 380 nm, λmax = 730 nm, and Δλ = 10 nm, 35 spectral reflectances can be obtained for each position in the x direction. When a plurality of types of reference patches PS1 are provided on the test chart TC1, a spectral reflectance can be obtained for each type of the reference patch PS1.

ここで、ｎは、ｘ方向へ並べられた基準パッチＰＳ１の数であり、２以上の整数である。図２（ａ）の例では、ｎ＝８となる。補正値Ｃ（λ，ｘ）は、ｘの関数であるとともに、λの関数でもある。従って、補正値Ｃ（λ，ｘ）は、Δλ（nm）間隔の各周波数λについて得られる。基準パッチＰＳ１が複数種類ある場合、各種類について補正値Ｃ（λ，ｘ）が得られる。 The spectral reflectance R (λ, x) of the reference patch PS1 is a color measurement result for reducing variation in the x direction of the color measurement result of the measurement patch PA1. Therefore, an inverse ratio of the spectral reflectance R (λ, x) at each x position to the average of the spectral reflectance R (λ, x) in the x direction is taken as an example of the correction value C (λ, x) at each x position. .

Here, n is the number of reference patches PS1 arranged in the x direction, and is an integer of 2 or more. In the example of FIG. 2A, n = 8. The correction value C (λ, x) is not only a function of x but also a function of λ. Accordingly, the correction value C (λ, x) is obtained for each frequency λ having an interval of Δλ (nm). When there are a plurality of types of reference patches PS1, correction values C (λ, x) are obtained for each type.

ここで、inkは、０〜１００％のインク吐出量を表すが、０〜２５５等の階調値で表されてもよい。得られる測色結果補正テーブルの値ｃ（ink，λ，ｘ）は、ｘ及びλの関数であるとともに、インク吐出量inkの関数でもある。従って、測色結果補正テーブル値ｃ（ink，λ，ｘ）は、ｘ方向の位置毎、Δλ（nm）間隔の周波数λ毎、かつ、インク吐出量ink毎に生成される。 The correction value C (λ, x) is a correction value for a certain ink discharge amount ink, such as 100% ink discharge amount, excluding the paper white reference patch PS1w. On the other hand, since the correction value C (λ, x) is a function of λ, it needs to be adjusted according to the ink discharge amount. Therefore, in order to correct the entire ink discharge amount of 0 to 100%, for example, the adjustment value α (ink) corresponding to the ink discharge amount ink is multiplied by the correction value C (λ, x) to generate the color measurement result correction table TA1. .

Here, ink represents an ink discharge amount of 0 to 100%, but may be represented by a gradation value such as 0 to 255. The value c (ink, λ, x) of the obtained colorimetric result correction table is a function of x and λ, and is also a function of the ink discharge amount ink. Accordingly, the colorimetric result correction table value c (ink, λ, x) is generated for each position in the x direction, for each frequency λ with an interval of Δλ (nm), and for each ink discharge amount ink.

Further, the color measurement result correcting means U3 shown in FIG. 1 corrects the color measurement result of the measurement patch PA1 according to the color measurement result correction table TA1. Here, the color measurement result of the measurement patch PA1 obtained by arranging the test chart TC1 in the color measurement region AC1 of the color measurement device 30 and performing color measurement by the color measurement device 30 is obtained by, for example, spectral reflectance R _target (λ, x , Y). Since the measurement patches PA1 are arranged in the x direction and the y direction, a spectral reflectance R (λ) is obtained for each position in the x direction and for each position in the y direction. Further, the spectral reflectance is obtained for each frequency λ with an interval of Δλ (nm). However, since the colorimetric result correction table value for correcting the spectral reflectance of the measurement patch at the same x position does not depend on the y position, the spectral reflectance variable y is not shown in FIG.

ここで、targetInkは、測色結果補正対象の測定用パッチＰＡ１のインク吐出量を表す。得られる分光反射率Ｒ’ _target（λ，ｘ）は、測定用パッチＰＡ１のｘ位置に応じて変わる関数であるとともに、λの関数でもある。従って、補正値Ｃ（λ，ｘ）は、Δλ（nm）間隔の各周波数λについて得られる。 The spectral reflectance R _target (λ, x) of the measurement patch PA1 is a color measurement result before correction. The color measurement result is multiplied by, for example, a color measurement result correction table value c (targetInk, λ, x) to obtain a corrected color measurement result R ′ _target (λ, x).

Here, targetInk represents the ink ejection amount of the measurement patch PA1 to be corrected for colorimetric results. The obtained spectral reflectance R ′ _target (λ, x) is a function that varies depending on the x position of the measurement patch PA1, and is also a function of λ. Accordingly, the correction value C (λ, x) is obtained for each frequency λ having an interval of Δλ (nm).

むろん、インク吐出量targetInkC，targetInkM，targetInkY，targetInkKと係数ｒ_c，ｒ_m，ｒ_y，ｒ_kとの対応関係を変換テーブルに規定しておいてもよい。この場合、この変換テーブルに従ってインク吐出量から係数ｒ_c，ｒ_m，ｒ_y，ｒ_kを求めて上記式（４）から測色結果補正テーブル値を求めてもよい。 When the reference patch PS1 is a primary color of paper white or only one kind of ink and the measurement patch PA1 is a primary color, the corrected colorimetric result R ′ _target (λ, x) is obtained from the above equation (3) only. Obtainable. When the measurement patch PA1 is a secondary color or more, the color measurement result correction table values c _w (ink, λ, x), c _c (ink, λ, x), c _m (ink, ink) for each color of the reference patch PS1 _{λ, x), c y (} ink, λ, x), c k (ink, λ, colorimetry result R _target (lambda in combination x) by linear interpolation or the like, x) may be corrected. Here, the ink discharge amounts of C, M, Y, and K in the measurement patch PA1 for secondary colors or more are set as targetInkC, targetInkM, targetInkY, and targetInkK, and the sum total of these ink discharge amounts is set as targetInkC + targetInkM + targetInkY + targetInkK. The colorimetry result correction table value c (targetInk, λ, x) used in the above equation (3) can be obtained as follows, for example.

Of course, the ink discharge amount targetInkC, targetInkM, targetInkY, targetInkK coefficient _{r c, r m, r y} , may be previously defined in the conversion table the correspondence between the r _k. In this case, the coefficient r _c from the ink discharge amount in accordance with the conversion table, r _m, r _y, may be seeking r _k seek colorimetry result correction table value from the equation (4).

When the second reference patch PS2 as shown in FIG. 3 is provided, the correction data generation unit U2 generates a second color measurement result correction table (second correction data) TA2 based on the color measurement result of the second reference patch PS2. Generate. The second color measurement result correction table TA2 is an information table for reducing variations in color measurement results in the y direction.
Here, the color measurement result of the second reference patch PS2 obtained by placing the test chart TC1 in the color measurement region AC1 of the color measurement device 30 and performing the color measurement by the color measurement device 30 is, for example, the spectral reflectance R (λ, y ). Since the second reference patches PS2 are arranged in the y direction, a spectral reflectance R (λ) is obtained for each position in the y direction. Further, the spectral reflectance is obtained for each frequency λ with an interval of Δλ (nm). When a plurality of types of second reference patches PS2 are provided on the test chart TC1, a spectral reflectance is obtained for each type of the second reference patch PS2.

ここで、ｍは、ｙ方向へ並べられた第二基準パッチＰＳ２の数であり、２以上の整数である。図３の例では、ｍ＝１０となる。補正値Ｃｙ（λ，ｙ）は、ｙ及びλの関数であり、Δλ（nm）間隔の各周波数λについて得られる。第二基準パッチＰＳ２が複数種類ある場合、各種類について補正値Ｃｙ（λ，ｙ）が得られる。 The spectral reflectance R (λ, y) of the second reference patch PS2 is a color measurement result for reducing variation in the y direction of the color measurement result of the measurement patch PA1. Therefore, the inverse ratio of the spectral reflectance R (λ, y) at each y position to the average of the spectral reflectances R (λ, y) in the y direction is taken as an example of the correction value Cy (λ, y) at each y position. .

Here, m is the number of second reference patches PS2 arranged in the y direction, and is an integer of 2 or more. In the example of FIG. 3, m = 10. The correction value Cy (λ, y) is a function of y and λ, and is obtained for each frequency λ having an interval of Δλ (nm). When there are a plurality of types of second reference patches PS2, a correction value Cy (λ, y) is obtained for each type.

得られる測色結果補正テーブル値ｃｙ（ink，λ，ｙ）は、ｙ方向の位置毎、Δλ（nm）間隔の周波数λ毎、かつ、インク吐出量ink毎に生成される。 The correction value Cy (λ, y) is a correction value at a certain ink discharge amount ink, such as 100% ink discharge amount, excluding the second white paper reference patch. In order to correct the entire ink discharge amount of 0 to 100%, for example, the second colorimetric result correction table TA2 is generated by multiplying the correction value Cy (λ, y) by the adjustment value α (ink) corresponding to the ink discharge amount ink. .

The obtained colorimetric result correction table value cy (ink, λ, y) is generated for each position in the y direction, for each frequency λ with an interval of Δλ (nm), and for each ink ejection amount ink.

ただし、同じｙ位置の測定用パッチの分光反射率を補正するための第二測色結果補正テーブル値はｘ位置に依存しないので、分光反射率の変数ｘを示していない。 得られる分光反射率Ｒ’ _target（λ，ｙ）は、測定用パッチＰＡ１のｙ位置に応じて変わる関数であるとともに、λの関数でもある。 Further, the color measurement result correcting unit U3 corrects the color measurement result of the measurement patch PA1 according to the second color measurement result correction table TA2. For example, the spectral reflectance R _target (λ, y) before correction of the measurement patch PA1 is multiplied by the second color measurement result correction table value cy (targetInk, λ, y) to correct the color measurement result R ′ _target ( λ, y).

However, since the second colorimetry result correction table value for correcting the spectral reflectance of the measurement patch at the same y position does not depend on the x position, the spectral reflectance variable x is not shown. The spectral reflectance R ′ _target (λ, y) obtained is a function that varies depending on the y position of the measurement patch PA1, and is also a function of λ.

測定用パッチＰＡ１が二次色以上の場合、第二基準パッチＰＳ２の色毎の第二測色結果補正テーブル値ｃｙ_w（ink，λ，ｙ），ｃｙ_c（ink，λ，ｙ），ｃｙ_m（ink，λ，ｙ），ｃｙ_y（ink，λ，ｙ），ｃｙ_k（ink，λ，ｙ）を組み合わせて測色結果Ｒ_target（λ，ｙ）を補正すればよい。 Of course, the color measurement result correction table value c (targetInk, λ, x) for reducing the variation in the x position and the second color measurement result correction table value cy (targetInk, λ, y) for reducing the variation in the y position. May be used simultaneously to correct the color measurement result.

When the measurement patch PA1 is a secondary color or more, the second colorimetric result correction table values cy _w (ink, λ, y), cy _c (ink, λ, y), cy for each color of the second reference patch PS2 _The color measurement result R _target (λ, y) may be corrected by combining _m (ink, λ, y), cy _y (ink, λ, y), and cy _k (ink, λ, y).

  Since the color measurement device 30 to be described later has less variation in the color measurement results in the y direction than variation in the color measurement results in the x direction, the second reference patch PS2 may be one type such as paper white only. Since the second reference patch only needs to be located in the x direction from the measurement patch, the second reference patch may be provided on both the left and right outer sides of the measurement patch area AP3 as shown in FIG. It may be provided only on the left side that is the front side in the x direction, or may be provided only on the right side that is the rear side in the x direction from the measurement patch.

When the color measurement result R _target (λ, x, y) is corrected, the corrected color measurement result R ′ _target (λ, x, y) is compared with the reference color measurement result RS (λ, x, y). As a result, as shown in the lower part of FIG. 1, the pre-correction print data PD1 can be corrected so as to compensate for the color shift of the print result by the printing unit U10 from the comparison result. The reference color measurement result RS (λ, x, y) is a color measurement result used as a reference for the color of the print result by the printing unit U10. The corrected print data PD2 is used by the printing unit U10 for outputting a print result.

(2) Configuration example of printing system:
4A to 4C illustrate the configuration of the printing systems 1 to 3 having the printing control apparatus U0. The printing system 1 shown in FIG. 1A is configured by connecting a host device 10 such as a personal computer (PC) to a printing device 20 such as an ink jet printer and a color measuring device 30 such as a color colorimeter. The host device 10 is a print control device U0 that holds information such as a colorimetry result correction table TA1, a second colorimetry result correction table TA2, and a patch arrangement table TP1. Here, as illustrated in FIG. 8A, the patch arrangement table TP1 indicates the position (xi, yi) and the ink discharge amount (Ci, Mi, Yi, Ki) of each patch constituting the test chart TC1. The associated information is stored. C, M, Y, and K represent cyan, magenta, yellow, and black inks, respectively. For example, in the case of the test chart TC1 shown in FIG. 2A, the positions (Xi, 1), (Xi, 2), (Xi, 3), (Xi, 4), and (Xi, 5) are respectively shown. The ink ejection amounts of the reference patches PS1w, PS1c, PS1m, PS1y, and PS1k are associated with each other, and the ink ejection amounts of the respective measurement patches PA1 are associated with the positions x = 1 to 8 and y = 6 to 15. In the case of the test chart TC1 shown in FIG. 3, the positions (1, yi), (2, yi), (3, yi), (12, yi), (13, yi) in the range of y = 6-15. ) Are associated with the ink discharge amounts of the second reference patches (w, c, m, y, k), respectively.

The printing apparatus 20 prints the test chart TC1 with the printing unit U10 under the control of the printing control apparatus U0. As a result, the test chart TC1 provided with at least the patches PS1 and PA1 arranged as described above is printed on the print medium PM1. The color measuring device 30 measures each of the plurality of patches PS1 and PA1 provided at least on the test chart TC1 printed on the print medium PM1 and arranged in the color measuring area AC1. The colorimetric results of each patch, that is, the spectral reflectance R (λ, x) of the reference patch, R _target (λ, x, y) of the measurement patch, and the spectral reflectance R (( λ, y) is sent to the host device 10.

  Since the correction tables TA1 and TA2 described above are information derived from the colorimetric unevenness of the colorimetric device 30, if they are generated by a certain host device, they can be used for other host devices. At this time, for example, the correction table can be transferred via a communication network such as a LAN (Local Area Network) or the Internet. Further, the correction table is stored in the memory device ME1 that is detachably connected to the interface (I / F) of the host device, the memory device ME1 is connected to another host device, and the other host device is connected. A correction table can also be read.

As illustrated in FIGS. 4B and 4C, the print control device U <b> 0 can be provided in addition to the host device 10. In the printing system 2 illustrated in FIG. 4B, the printing apparatus 20 includes a printing control apparatus U <b> 0, and the color measurement apparatus 30 is connected to the printing apparatus 20. Accordingly, the printing apparatus 20 acquires the color measurement result of the test chart TC1 from the color measurement apparatus 30, generates at least the color measurement result correction table TA1 based on the color measurement result R (λ, x) of the reference patch, and performs the measurement. The color measurement result R _target (λ, x, y) of the patch is corrected.
Of course, the color measuring device 30 may be provided with a print control device U0.

In the printing system 3 illustrated in FIG. 4C, the printing apparatus 20 includes a color measuring device 30 like a printer with a color measuring machine, and the host device 10 is connected to the printing apparatus 20.
The print control device U0 is provided across the host device 10 and the printing device 20, is provided across the host device 10 and the color measurement device 30, or is provided across the print device 20 and the color measurement device 30. Or may be provided across all the devices 10, 20, and 30.

  As illustrated in FIG. 5, the host device 10 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, various devices 14 to 17, and a communication interface (I / F). 18, 19, etc. are connected to the bus so that information can be input and output with each other. The storage device 14 stores an operating system OS, a printer driver PD, correction tables TA1 and TA2, a patch arrangement table TP1, and the like. As the storage device 14, a magnetic storage device such as a hard disk, a nonvolatile semiconductor memory such as a flash memory, or the like can be used. The printer driver PD causes the host device 10 to function as the print control device U0. The input device 15 includes an operation input device such as a keyboard or a pointing device. The output device 16 includes an image output device such as a display, an audio output device, and the like. The data input / output device 17 inputs / outputs data to / from a recording medium when a computer-readable recording medium is detachably connected. The communication I / F 18 is connected to the communication I / F 21 of the printing apparatus 20 and inputs / outputs information to / from the printing apparatus 20. The communication I / F 19 is connected to the color measurement device 30 and inputs / outputs information to / from the color measurement device 30.

  The printing apparatus 20 is an inkjet printer including a communication I / F 21, a control unit 22, various drive units 23 to 25, a carriage 26, a CMYK recording head 28, and the like, and a CMYK ink cartridge 27 is mounted on the carriage 26. Shall. The printing unit U10 that outputs a printing result corresponding to the corrected print data PD2 includes, for example, the units 22 to 28 of the printing apparatus 20.

  The control unit 22 controls operations of the various drive units 23 to 25. The control unit 22 may be configured by specific means in which software and hardware resources cooperate with each other, may be basically configured by specific means in which software is read into a computer, or an ASIC (Application An integrated circuit such as a specific IC (specific application integrated circuit) may basically be configured by hardware resources. The transport driving unit 23 performs transport driving for feeding the print medium PM <b> 1 in a predetermined feeding direction (y direction) according to the control of the control unit 22. The carriage drive unit 24 drives the carriage 26 to reciprocate in the main scanning direction (x direction) orthogonal to the feed direction according to the control of the control unit 22. The head drive unit 25 generates an ejection waveform pulse by an internal drive signal generation circuit under the control of the control unit 22 and supplies this voltage pulse to the drive element. As the drive element, a piezoelectric drive element such as a piezo element, an electrostatic drive element, a heater that heats ink and discharges a fluid from a nozzle using the pressure of a bubble caused by film boiling, and the like can be used. . The printing apparatus 20 discharges CMYK ink filled in the ink cartridge 27 from each nozzle of the recording head 28, and attaches ink droplets to the printing medium PM1 such as printing paper to form dots. As a result, an image corresponding to print data representing a color image is printed.

The color of fluid discharged from each nozzle is lighter than light cyan (Lc), light magenta (Lm), dark yellow (DY), light black (Lk), and Lk in addition to the above-described C, M, Y, and K. Various colors such as LLk and colorless can be used. The present technology can also be applied to the case where the same color fluid is discharged from all nozzles as in a single color machine. Examples of the ink include a fluid in which a color material composed of a fine pigment is mixed in an aqueous solvent, a fluid in which a color material composed of a dye is mixed, and a fluid in which a color material is mixed in an oil-based solvent.
Examples of the print medium include a coated paper print medium including glossy paper such as photographic paper, and a non-coated paper print medium including plain paper and recycled paper. Matte paper is a printing medium in which the surface of the paper is coated with a matte coating, and is also called matte paper. Since matte paper has less gloss, it is suitable when measuring colorimetric unevenness of the colorimetric device 30.

FIGS. 6A and 6B and FIG. 7A illustrate the main part of the color measuring device 30. The color measurement device 30 includes a white backing material 31, a carriage 33 provided with a color measurement sensor 32, a carriage guide 34, a print medium feeding mechanism 35, a control unit 36, a paper feed sensor (not shown), and the like. .
The backing material 31, also called backing, is arranged on the back side PM1b of the print medium PM1, that is, on the back side of the test chart TC1. The backing material 31 is installed substantially horizontally with its longitudinal direction facing the main scanning direction DR1 of the colorimetric sensor 32, and reflects upwardly the light traveling downward from the colorimetric sensor 32 through the print medium PM1. . The colorimetric sensor 32 is arranged on the front side PM1a of the print medium PM1, that is, on the front side of the test chart TC1. The colorimetric sensor 32 includes a light irradiation unit and a sensor unit, irradiates the test chart TC1 on the backing material 31 with light from the light irradiation unit, is reflected by the patch PA1 and the backing material 31, and returns. The detected light is detected by the sensor unit. The carriage 33 reciprocates in the main scanning direction DR1 along the carriage guide 34 under the control of the controller 36. The main scanning direction DR1 is the x direction of the test chart TC1. The feed mechanism 35 feeds the print medium PM1 in the feed direction DR2 orthogonal to the main scanning direction DR1 according to the control of the control unit 36. This feed direction DR2 is the y direction of the test chart TC1. The paper feed sensor detects whether or not the print medium PM1 is disposed at a position corresponding to the predetermined colorimetric area AC1.

  The print medium PM1 supplied to the color measuring device 30 is provided with a test chart TC1 arranged in the color measuring region AC1 of the color measuring device 30. The test chart TC1, for example, has patches arranged in an orderly manner in the main scanning direction DR1 (x direction) and the feed direction DR2 (y direction), and a mark PA2 for confirming the y position of the patch is appropriately provided in the test chart TC1. Provided outside.

Depending on the colorimetric device 30, colorimetric unevenness occurs in which the spectral reflectance detected by the colorimetric sensor 32 differs depending on the position of the patch even though the same patch is colorimetrically measured. FIG. 7A shows the main part of the color measurement device 30 in which the color measurement unevenness is exaggerated from the front. The white backing material 31 of the color measuring device 30 was recessed toward the center in the x direction, which is the main scanning direction DR1 of the color measuring sensor 32, and the gap with the print medium PM1 was large. Nothing average value of the spectral reflectance with respect to the position x in the main scanning direction DR1 when a white matte paper which is not printed and measured spectral reflectance is supplied to the colorimetric device _{30 (1 / N λ) ΣR} (λ ) Is shown in FIG. Here, ΣR (λ) is the spectral reflectance R (λ) of each frequency λ that is set to an interval of Δλ (nm) from the minimum wavelength λmin (nm) detected by the colorimetric sensor 32 to the maximum wavelength λmax (nm). The sum is shown. N _λ indicates the number of R (λ) for which the sum is obtained, that is, {(λmax−λmin) / Δλ} +1. For example, if λmin = 380 nm, λmax = 730 nm, and Δλ = 10 nm, N _λ = 35. As shown in FIG. 7B, the average value of the spectral reflectance is small in the central portion where the gap between the print medium PM1 and the backing material 31 is large. For this reason, if the backing material 31 is white, the irradiation light reflected by the backing material 31 is relatively large. On the other hand, if the gap between the printing medium PM1 and the backing material 31 is large, the backing material 31 reflects and prints. It is estimated that the amount of irradiation light that passes through the medium PM1 and enters the colorimetric sensor 32 is reduced.

When the backing material is black, the amount of irradiation light reflected by the backing material is small, and the influence of the shape of the backing material on the color measurement results such as spectral reflectance is reduced. However, there are many white types of backing materials for color measuring devices.
If the backing material is lighter than black, such as gray, and darker than white, the shape of the backing material may affect the colorimetric results, such as spectral reflectance, although not as much as the white backing material. Therefore, the present technology is preferable when a color measuring device having a non-black backing material is used, more preferably in the case of a light-colored backing material, and particularly preferable in the case of a white backing material.

  Further, even if an attempt is made to provide the colorimetric device with a mechanism for pressing the colorimetric sensor against the backing material with the printing medium sandwiched therebetween in order to eliminate the influence of the gap between the printing medium and the backing material, this mechanism is complicated. Therefore, there is a concern that it cannot be provided in the color measuring device, or even if it can be provided, it is too costly. In particular, the provision of a mechanism for pressing the colorimetric sensor on a colorimeter that is inexpensive and speeds up colorimetry is contrary to the objective of the cost reduction and speedup.

In addition, if the color measurement device is used for a long time, the color measurement results will change due to deterioration of the light source of the color measurement sensor, dirt on the backing material, scratches or wear. It is assumed that it will come. On the other hand, it is assumed that the color measurement result changes even if the carriage axis of the color measurement sensor is deviated.
Therefore, a colorimetry result correction table is generated based on the colorimetry results of reference patches of a certain density arranged in the x direction, and the colorimetry results of the measurement patches provided on the same test chart (print medium) are measured. Correction is made according to the color result correction table.

  In the test chart TC1, mat paper is preferable, light-colored mat paper is more preferable, and white mat paper is particularly preferable. Since the matte paper diffuses and reflects the light emitted from the colorimetric sensor 32, the influence of the light reflected by the matte paper is small and suitable for examining the influence of the light reflected by the backing material 31.

  FIGS. 8A and 8B show the patch arrangement table TP1. The patch placement table TP1 stores information that associates the patch position (xi, yi) and the ink ejection amount (Ci, Mi, Yi, Ki) for each patch placed on the test chart TC1. In the example of FIG. 8B, the patch No. It is indicated that the ink discharge amount of Pi is (Ci, Mi, Yi, Ki).

(3) Operation, action, and effect of print control device:
FIG. 9 illustrates a color measurement result acquisition process performed by the print control apparatus U0 as a flowchart. This process starts when an input from a user instructing acquisition of a colorimetric result is received from the input device 15 or the like, and is performed in parallel with other processes by multitasking. Here, steps S102 to S104 correspond to the test chart print control means U1, the test chart print control process, and the test chart print control function, and steps S110 to S116 correspond to the correction data generation means U2, the correction data generation process, and the correction data generation function. Steps S118 to S120 correspond to the colorimetry result correction unit U3, the colorimetry result correction process, and the colorimetry result correction function. Hereinafter, the description of “step” is omitted. During the flow, at least the process indicated by the broken line can be omitted.

  When the colorimetric result acquisition process starts, the print control device U0 reads the patch placement table TP1 from the storage device 14 and the like, and places the test chart print data, which is raster data for causing the printing device 20 to print the test chart TC1, in the patch placement. It is generated from the table TP1 (S102). For example, gradation data composed of gradation values for each CMYK is generated from the patch arrangement table TP1, multi-value data in which the number of gradations is reduced by performing predetermined halftone processing on the gradation data, If a predetermined rasterizing process is performed on the multi-value data, test chart print data that is raster data can be generated. Here, the gradation data can be 256 gradations or the like. The multi-value data can be two gradations representing the presence or absence of dot formation, four gradations representing any one of large dot formation, medium dot formation, small dot formation, and no dot.

  In S104, the test chart print data is sent to the printing apparatus 20. The printing apparatus 20 that has acquired the test chart print data prints the test chart TC1 by the printing unit U10 based on the test chart print data.

In S106, the colorimetric device 30 is instructed to perform colorimetry on the test chart TC1 formed on the printing medium PM1 such as matte paper. The color measurement device 30 detects whether or not the print medium PM1 is arranged at a position corresponding to the predetermined color measurement area AC1 with the paper feed sensor, and when it is detected that the print medium PM1 is arranged. The feeding mechanism 35 feeds the print medium PM1 in the feeding direction DR2, and measures the color of each patch in the test chart TC1 while reciprocating the colorimetric sensor 32 in the main scanning direction DR1. A colorimetric result R (λ, x) is obtained for each position in the x direction from the reference patch area AP1, and a colorimetric result R _target (λ, x) is obtained for each position in the x and y directions from the area AP3 for the measurement patch. x, y) is obtained. When the reference patch PS1 is present in a plurality of rows in the y direction, the color measurement result R (λ, x) of the reference patch is obtained for each position in the y direction. When there is the second reference patch area AP2, a color measurement result R (λ, y) is obtained for each position in the y direction. When the second reference patch PS2 is present in a plurality of rows in the x direction, the color measurement result R (λ, y) of the second reference patch is obtained for each position in the x direction.

  Note that the color measurement of the test chart TC1 may be performed a plurality of times, such as three times or more, in order to eliminate the possibility that sudden abnormal values are included in the color measurement result. When the color measurement is performed three or more times, the color measurement value (average value if there are plural values) excluding the maximum value and the minimum value may be used as the color measurement result. Of course, such an aspect is not essential, and an average value of all the colorimetric values may be used as a colorimetric result, or a colorimetric value obtained only once may be used as a colorimetric result.

The print control device U0 determines the color measurement result R (λ, x) of the reference patch, the color measurement result R _target (λ, x, y) of the measurement patch, and the color measurement result R (( (λ, y) is acquired from the color measuring device 30 and stored in the storage device 14 or the like (S108).

In S110, based on the colorimetric result R (λ, x) of the reference patch, the correction value C (λ, x) exemplified in the above equation (1) is acquired. For example, an inverse ratio of the spectral reflectance R (λ, x) at each x position to the average of the spectral reflectances R (λ, x) in the x direction is set as a correction value C (λ, x) at each x position. When the reference patch PS1 has a plurality of rows, the correction value C (λ, x) is acquired for each y position.
In S112, based on the correction value C (λ, x) and the adjustment value α (ink) corresponding to the ink discharge amount ink, each value c (ink) of the colorimetry result correction table exemplified in the above equation (2). , Λ, x). For example, c (ink, λ, x) is obtained by multiplying C (λ, x) by α (ink) for each ink for each x and λ having an interval of Δλ (nm).

If necessary, in S114, the correction value Cy (λ, y) exemplified in the above equation (5) is acquired based on the color measurement result R (λ, y) of the second reference patch. For example, an inverse ratio of the spectral reflectance R (λ, y) at each y position with respect to the average of the spectral reflectances R (λ, y) in the y direction is set as a correction value Cy (λ, y) at each y position. When the second reference patch PS2 has a plurality of rows, the correction value Cy (λ, y) is acquired for each x position.
In S116, based on the correction value Cy (λ, y) and the adjustment value α (ink) corresponding to the ink discharge amount ink, each value cy of the second colorimetry result correction table exemplified in the above equation (6). (Ink, λ, y) is generated. For example, cy (ink, λ, y) is obtained by multiplying Cy (λ, y) by α (ink) for each ink at every y and every λ at Δλ (nm) intervals.

In S118, based on the color measurement result correction table value c (ink, λ, x), the color measurement result R _target (λ, x) of the measurement patch provided at the position in the y direction from the reference patch for each x position. ) Is corrected. For example, according to the above equation (3), the corrected color measurement result R ′ is obtained by multiplying R _target (λ, x) by c (targetInk, λ, x) corresponding to the ink ejection amount targetInk of the color measurement result correction target patch. _{Find target} (λ, x).

If necessary, the print control device U0 performs measurement provided at a position in the x direction from the second reference patch for each y position based on the second colorimetry result correction table value c (ink, λ, y). The color measurement result R _target (λ, y) of the patch is corrected (S120), and the color measurement result acquisition process is terminated. For example, according to the above equation (7), R _target (λ, y) is multiplied by cy (targetInk, λ, y) corresponding to the ink discharge amount targetInk of the color measurement result correction target patch, and the color measurement result R ′ after correction is performed. _{Find target} (λ, y). When correcting the color measurement result of the measurement patch based on the color measurement result of the second reference patch, the color measurement result correction table is added to the color measurement result R _target (λ, x, y) before correction according to the above equation (8). The corrected colorimetric result R ′ _target (λ, x, y) may be obtained by multiplying the value c (ink, λ, x) and the second colorimetric result correction table value c (ink, λ, y). .
The corrected colorimetric result R ′ _target (λ, x, y) may be stored in the storage device 14 or the like.

As described above, the color measurement result correction table value c (ink, λ, x) is correction data for reducing variations in color measurement results in the x direction. Since the color measurement result R _target (λ, x) of the measurement patch PA 1 provided at the position in the y direction from the reference patch PS 1 is corrected according to c (ink, λ, x), the color measurement result in the x direction Variability is reduced. Therefore, this aspect can obtain a color measurement result in which the color measurement unevenness of the color measurement device 30 is reduced.
The second color measurement result correction table value c (ink, λ, y) is second correction data for reducing variations in the color measurement results in the y direction. Since the color measurement result R _target (λ, y) of the measurement patch PA1 provided at the position in the x direction from the second reference patch PS2 is corrected according to c (ink, λ, y), the color measurement in the y direction is performed. Variation in results is also reduced. Therefore, this aspect can obtain a color measurement result in which the color measurement unevenness of the color measurement device 30 is further reduced.

The corrected colorimetric result R ′ _target (λ, x, y) can be used for calibration to compensate for color misregistration by the printing unit U10.

FIG. 10A illustrates a color correction table generation process performed by the print control apparatus U0 as a flowchart. This process starts when an input from a user instructing calibration of the printing apparatus 20 is received from the input apparatus 15 or the like, and is performed in parallel with other processes by multitasking.
When the color correction table generation process starts, the print control device U0 acquires the corrected colorimetric result R ′ _target (λ, x, y) (S202). For example, R ′ _target (λ, x, y) is read into the RAM 13 from the storage device 14 or the like.

In S204, a reference colorimetry result RS (λ, x, y) as a reference for the color of the printing result by the printing unit U10 is acquired. The reference color measurement result RS (λ, x, y) can be a spectral reflectance obtained by measuring a plurality of patches formed on a reference print medium with a reference color measurement device, and is attached to the printer driver PD in advance. What is necessary is just to memorize | store in the memory | storage device 14 grade | etc., As data. Of course, the reference color measurement result may be acquired from the outside via a communication network such as the Internet.
In S206, the corrected colorimetric result R ′ _target (λ, x, y) and the reference colorimetric result RS (λ, x, y) are compared for each measurement patch PA1, and the color correction table representing the comparison result is obtained. Is generated. This color correction table is obtained, for example, from the corrected spectral reflectance R ′ _target (λ, x, y) to the reference spectral reflectance RS (λ, x, y) for each frequency λ at intervals of Δλ (nm) for each measurement patch PA1. A table of data representing a deviation R ′ _target (λ, x, y) −RS (λ, x, y) obtained by subtracting y) may be used. As the data of the color correction table, R ′ _target (λ, x, y) / RS (λ, x, y) or the like is also possible. When color values (for example, L, a, b) in a color space such as the Lab color space are obtained as colorimetric results, for example, data representing a shift for each color value can be used as data in the color correction table. . The comparison result may be incorporated in a color conversion table for color-converting R (red), G (green), and B (blue) image data into CMYK image data, for example. This color conversion table is also a color correction table.

  Finally, the print control device U0 stores the color correction table in the storage device 14 or the like (S208), and ends the color correction table generation process.

FIG. 10B illustrates a print control process performed by the print control apparatus U0 using a flowchart. This process starts when an input from a user instructing printing of an image or the like to be printed is received from the input device 15 or the like, and is performed in parallel with other processes by multitasking.
When the print control process starts, the print control device U0 reads the color correction table from the storage device 14 or the like (S222).

In S224, pre-correction print data PD1 is acquired. For example, when RGB image data is color-converted into CMYK image data, for example, the CMYK image data after color conversion can be acquired as pre-correction print data PD1. Of course, RGB image data before color conversion, CMYK image data after gradation number conversion after halftone processing, and the like may be used as pre-correction print data PD1.
In S226, the pre-correction print data PD1 is corrected with reference to the color correction table so as to compensate for the color shift of the print result. When data representing a colorimetric result deviation is stored in the color correction table, the pre-correction print data PD1 is corrected by subtracting the colorimetric result deviation from the pre-correction print data PD1 to obtain the corrected print data PD2. Can be generated. As a result, the corrected print data PD2 that is used to output the print result after the color misregistration of the print result is compensated can be printed by the printing unit U10. Of course, when the color conversion table is a color correction table, the color conversion table is referred to and image data before color conversion such as RGB (pre-correction print data PD1) is color-converted to represent image data such as CMYK. The corrected print data PD2 can be generated.

In S228, raster data is generated from the corrected print data PD2. For example, predetermined halftone processing is performed on the corrected print data PD2 composed of gradation values for each CMYK to generate multi-value data with a reduced number of gradations, and predetermined rasterization is performed on the multi-value data. If processing is performed, raster data can be generated. Of course, the corrected print data PD2 can be 256 gradations, and the multi-value data can be 2 gradations, 4 gradations, or the like.
Finally, the printing control device U0 sends the raster data to the printing device 20 (S230), and ends the printing control process. The printing apparatus 20 that has obtained the raster data prints an image on a print medium by the printing unit U10 based on the raster data.

  As described above, according to the present technology, the colorimetric results of the measurement patches are corrected based on the colorimetric results from the reference patches arranged in the x direction and, if necessary, the second reference patches arranged in the y direction. Therefore, a color measurement result with reduced color measurement unevenness of the color measurement device can be obtained. As a result, even when using a color measurement device that is inexpensive and speeds up color measurement, color misregistration compensation of the printing unit can be performed with high accuracy.

(4) Modification:
The embodiment described above can also be changed to the following form.
The order of the steps of the above-described processing can be changed as appropriate. For example, in the color measurement result acquisition process of FIG. 9, the second color measurement result correction table value generation in S116 may be performed before the color measurement result correction table value generation in S112.
In the above-described embodiment, spectral reflectance is used as a measurement result. However, as a color measurement result, a combination of L value, a value, and b value defined in the Lab color space, an X value defined in the XYZ color space, A combination of Y value and Z value, lightness L, darkness obtained by subtracting lightness L from the maximum lightness value in the color space, and the like may be used.

むろん、補正テーブル値ｃ（ink，λ，ｘ），ｃｙ（ink，λ，ｙ）についても、様々な態様が考えられ、上述した実施形態の逆数等とすることができる。
また、上述した実施形態では補正値Ｃ，Ｃｙや補正テーブル値ｃ，ｃｙが分光反射率の平均を基準とした相対値とされているが、補正値Ｃや補正テーブル値ｃはあるｘ位置の分光反射率等を基準とした相対値とされてもよいし、補正値Ｃｙや補正テーブル値ｃｙはあるｙ位置の分光反射率等を基準とした相対値とされてもよい。 Various modes can be considered for the correction values C (λ, x) and Cy (λ, y). For example, if the reciprocal of the correction value is used when generating the correction tables TA1 and TA2, each spectral reflectance relative to the average of the spectral reflectances may be used as the correction value. A modification of the correction value C (λ, x) is shown below.

Of course, various modes can be considered for the correction table values c (ink, λ, x) and cy (ink, λ, y), and they can be the reciprocals of the above-described embodiments.
In the above-described embodiment, the correction values C and Cy and the correction table values c and cy are relative values based on the average of the spectral reflectance, but the correction value C and the correction table value c are at a certain x position. The relative value may be a relative value based on the spectral reflectance or the like, and the correction value Cy or the correction table value cy may be a relative value based on the spectral reflectance or the like at a certain y position.

The color measurement device is not only a device that scans the color measurement sensor while feeding the print medium to measure each patch in a two-dimensional arrangement, but also measures the color of each patch while moving the color measurement sensor in both x and y directions. Or a device that measures the color of each patch while moving the printing paper in both the x and y directions.
In addition to paper, the print medium may be a resin sheet, a metal film, a cloth, a film substrate, a resin substrate, a semiconductor wafer, a storage medium such as an optical disk or a magnetic disk, and the like. The shape of the recording medium may be a long shape, a three-dimensional shape, etc. in addition to a cut sheet.

In addition to a color ink jet printer, the printing apparatus may be a single color machine, a dot impact type printer, a laser printer, a multifunction machine having a reading unit such as a scanner or a colorimeter, or the like.
The printing apparatus to which the present invention can be applied may be an apparatus that ejects fluid other than ink, such as a liquid ejection apparatus that includes a liquid ejection head that ejects (discharges) a minute amount of liquid droplets. The term “droplet” as used herein refers to the state of the liquid ejected from the liquid ejecting apparatus, and includes a granular shape, a tear shape, a thread-like shape, and the like. The liquid here may be any material that can be discharged by the liquid discharge device. For example, as a liquid in a state when the substance is in a liquid phase, a liquid material having a high or low viscosity, sol, gel water Inorganic solvents, organic solvents, solutions, liquid resins, fluids such as liquid metals (metal melts), and the like are included. Further, not only a liquid as one state of a substance but also a substance in which particles of a functional material made of a solid such as a pigment or a metal particle are dissolved, dispersed or mixed in a solvent are included. Ink, liquid crystal, and the like are typical examples of liquids. The ink includes general water-based ink and oil-based ink, and various liquid compositions such as gel ink and hot melt ink. Examples of the liquid ejection device include a device for ejecting a liquid containing a material such as an electrode material or a color material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface emitting display, or a color filter in a dispersed or dissolved state. Is included. In addition, the liquid ejection device is a device that ejects biological organic materials used in biochip manufacturing, a device that ejects liquid as a sample used as a precision pipette, a textile printing device, a microdispenser, a clock or a camera. In order to etch a substrate, a device for discharging a transparent resin liquid such as an ultraviolet curable resin to form a device for discharging lubricating oil, a micro hemispherical lens (optical lens) used for an optical communication element, etc. An apparatus for discharging an etching solution such as acid or alkali is included.
The fluid is preferably a non-gaseous fluid, but may be a granular material such as toner.

It is not essential that the color measuring device has a white backing material, and it is not essential that the reference patch first read by the color measuring device is paper white, and the second reference patch is provided on the test chart. It is not essential to place it.
Needless to say, a printing apparatus, a system, a method, and a test chart for printing a test chart in a printing unit under the control of a printing control apparatus, an apparatus that does not have the structural requirements according to the dependent claims and that includes only the structural requirements according to the independent claims The basic operations and effects described above can also be obtained by using a print medium, a program, or the like on which a test chart is formed.

As described above, according to the present invention, a technique for obtaining a color measurement result with reduced color measurement unevenness of the color measurement device can be provided according to various aspects.
In addition, it is also possible to implement the present invention by mutually replacing the configurations disclosed in the above-described embodiments and modifications, and changing the combination. It is also possible to carry out the present invention by substituting each component disclosed in the above or changing the combination. Therefore, the present invention is not limited to the above-described embodiments and modifications, and includes configurations in which the configurations disclosed in the publicly known technology and the above-described embodiments and modifications are mutually replaced or combinations thereof are changed. It is.

1, 2, 3 ... Printing system, 10 ... Host device, 20 ... Printing device, 30 ... Color measuring device, 31 ... Backing material, 32 ... Color measuring sensor, AC1 ... Predetermined color measuring area, AP1 ... Reference patch Area, AP2 ... second reference patch area, AP3 ... measurement patch area, PA1 ... measurement patch, PM1 ... print medium, PS1, PS1w, PS1c, PS1m, PS1y, PS1k ... reference patch, PS2 ... second reference Patch, TA1 ... Colorimetry result correction table (correction data), TA2 ... Second colorimetry result correction table (second correction data), TC1 ... Test chart, TP1 ... Patch arrangement table, U0 ... Print control device, U1 ... Test Chart printing control means, U2 ... correction data generation means, U3 ... colorimetric result correction means, U10 ... printing section.

Claims (8)

A print control device for causing a patch to print each patch for a color measuring device that measures colors of the patches arranged in the x direction and the y direction intersecting each other, and obtaining a color measurement result of each patch,
A test chart printing control unit that causes the printing unit to print a test chart having a reference patch having a constant density arranged in the x direction and a measurement patch provided at a position in the y direction from the reference patch;
Correction data generating means for generating correction data for reducing variations in the color measurement results in the x direction based on the color measurement results of the reference patch obtained by measuring the test chart with the color measurement device;
A print control apparatus comprising: a color measurement result correcting unit that corrects a color measurement result of the measurement patch obtained by measuring the test chart with the color measurement apparatus according to the correction data. The correction data generation unit is configured to output the correction data for reducing variation in spectral reflectance in the x direction based on spectral reflectance of the reference patch obtained by measuring the test chart with the colorimetric device. Generate and
2. The printing according to claim 1, wherein the color measurement result correcting unit corrects a spectral reflectance of the measurement patch obtained by measuring the test chart with the color measuring device according to the correction data. Control device. The test chart printing control means causes the printing unit to print the test chart in which the second reference patches having a constant density arranged in the y direction are provided at the position in the x direction from the measurement patch,
The correction data generation means is a second unit for reducing variation in color measurement results in the y direction based on the color measurement results of the second reference patch obtained by measuring the test chart with the color measurement device. Generate correction data,
2. The color measurement result correcting means corrects the color measurement result of the measurement patch obtained by measuring the test chart with the color measuring device according to the second correction data. Item 3. The print control apparatus according to Item 2.   The test chart has different reference patches at different positions in the y direction, and a portion of the reference patches that is not read on the print medium by the reference patch first read by the colorimetric device is printed in the x direction. The print control apparatus according to any one of claims 1 to 3, wherein the print control apparatuses are arranged in a line. The colorimetric device comprises a white backing material disposed on the back side of the test chart and a colorimetric sensor disposed on the front side of the test chart,
The correction data generation means reduces variations in the color measurement results in the x direction based on the color measurement results of the reference patch obtained by measuring the test chart formed on the mat paper with the color measurement device. To generate correction data for
The color measurement result correcting means corrects a color measurement result of the measurement patch obtained by measuring a color of a test chart formed on the mat paper with the color measuring device according to the correction data. The printing control apparatus as described in any one of Claims 1-4.   6. A printing apparatus, wherein the test chart is printed by the printing unit under the control of the printing control apparatus according to claim 1. A printing control method for causing a patch to print each patch for a color measuring device that performs color measurement on each patch arranged in the x and y directions intersecting each other, and obtaining a color measurement result of each patch,
A test chart printing control step for causing the printing unit to print a test chart having a reference patch of a certain density arranged in the x direction and a measurement patch provided at a position in the y direction from the reference patch;
A correction data generation step for generating correction data for reducing variations in the color measurement results in the x direction based on the color measurement results of the reference patch obtained by measuring the test chart with the color measurement device;
A print control method comprising: a color measurement result correcting step of correcting a color measurement result of the measurement patch obtained by measuring the test chart with the color measuring device according to the correction data. Print control for causing a computer to realize a function of printing each patch for a color measurement device that measures colors of the patches arranged in the x direction and the y direction intersecting each other on a printing unit and obtaining a color measurement result of each patch A program,
A test chart printing control function for causing the printing unit to print a test chart having a reference patch of a certain density arranged in the x direction and a measurement patch provided at a position in the y direction from the reference patch;
A correction data generation function for generating correction data for reducing variations in the color measurement results in the x direction based on the color measurement results of the reference patch obtained by measuring the test chart with the color measurement device;
A print control program that realizes a color measurement result correction function that corrects a color measurement result of the measurement patch obtained by measuring the test chart with the color measurement device according to the correction data.

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