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EP-4385744-B1 - COLOR MANAGEMENT APPARATUS, COLOR MANAGEMENT METHOD, AND PROGRAM

EP4385744B1EP 4385744 B1EP4385744 B1EP 4385744B1EP-4385744-B1

Inventors

  • MAKUTA, TOSHIYUKI
  • SASADA, MISATO
  • TAMAGAWA, KIYOMI
  • KAWAMOTO, TAKUMA

Dates

Publication Date
20260506
Application Date
20220810

Claims (17)

  1. A system (100) comprising an inkjet printer (12) and a color management apparatus (10) coupled for communication with the inkjet printer (12); wherein the ink jet printer (12) comprises an ink discharge device (14) and a controller (15); wherein the color management apparatus (10) comprises at least one processor (42, 42A) configured to: (A) cause the ink discharge device (14) to form a print pattern by discharging (i) a cyan specific ink composition C according to a C1 signal value, (ii) a magenta specific ink composition M according to an M1 signal value and (iii) a yellow specific ink composition Y according to a Y1 signal value, each of the specific ink compositions C, M, Y having respective amounts (a1, b1; a2, b2 ; a3, b3) of a liquid crystal compound and of a chiral compound, the C1 signal value, M1 signal value and Y1 signal value together constituting a second signal value; (B) from the amounts of the liquid crystal compound and the chiral compound in the specific ink compositions C, M, Y, determine the total amounts of the liquid crystal compound and the chiral compound in the in the print pattern formed by mixing the specific ink compositions; (C) associate the total amounts of the liquid crystal compound and the chiral compound in the print pattern with the second signal value; (D) measure the color of the print pattern formed as a color chart using the specific ink compositions, so as to determine a chromaticity value of the color chart; (E) associate the total amounts of the liquid crystal compound and the chiral compound in the in the print pattern with the measured chromaticity value; and (F) repeat (A) to (E) in respect of multiple different second signal values having corresponding amounts of the liquid crystal compound and chiral compound, whereby a respective second chromaticity value is derived, and whereby a color profile (CP) is created therefrom in which each of the second chromaticity value and the second signal value is associated with amounts of the liquid crystal compound and the chiral compound; (G) perform conversion between a first signal value and a first chromaticity value through the color profile (CP).
  2. The system (100) according to claim 1, wherein the color profile (CP) is created under a condition in which the amounts of the liquid crystal compound and the chiral compound associated with the second chromaticity value and the amounts of the liquid crystal compound and the chiral compound associated with the second signal value are at least partially the same.
  3. The system (100) according to claim 1 or 2, wherein the processor (42, 42A) is configured to: select one from a plurality of selective color profiles as the color profile (CP).
  4. The system (100) according to claim 3, wherein the plurality of selective color profiles include at least two color profiles having color measurement conditions of the second chromaticity value different from each other.
  5. The system (100) according to claim 4, wherein at least one of an incidence angle of color measurement light or a light-receiving angle of reflected light is different between the color measurement conditions.
  6. The system (100) according to claim 4, wherein a background color of the color chart is different between the color measurement conditions.
  7. The system (100) according to claim 1 or 2, wherein the second chromaticity value includes chromaticity values of color charts formed of at least two ink compositions forming the color charts having maximum reflection wavelengths different from each other.
  8. The system (100) according to claim 7, wherein the color chart has a black background, and the second chromaticity value includes a value measured under a condition in which an incidence angle of color measurement light is 15° and a light-receiving angle of reflected light is 0°, in the color chart formed of one specific ink composition of the at least two specific ink compositions, the maximum reflection wavelength is 430 nm or less, and in the color chart formed of the other specific ink composition of the at least two specific ink compositions, the maximum reflection wavelength is 640 nm or less.
  9. The system (100) according to claim 1 or 2, wherein the second chromaticity value is determined through simulation.
  10. The system (100) according to claim 1 or 2, wherein the color profile (CP) defines a color hue circle consisting of the second chromaticity value of the color chart, and the color hue circle does not include an achromatic region.
  11. The system (100) according to claim 1 or 2, wherein the color profile (CP) is a look-up table.
  12. The system (100) according to claim 1 or 2, wherein the processor (42, 42A) is configured to: perform conversion from a signal value of image data to a signal value of a device via first conversion which is the conversion between the first signal value and the first chromaticity value.
  13. The system (100) according to claim 12, wherein the device is a monitor, the first signal value is the signal value of the image data, and the processor (42, 42A) is configured to: perform the first conversion which is conversion from the signal value of the image data to the first chromaticity value through the color profile (CP); and perform second conversion which is conversion from the first chromaticity value to an RGB signal value of the monitor through a monitor profile of the monitor.
  14. The system (100) according to claim 12, wherein the device is an ink jet printer (12), the first chromaticity value is a signal value of the ink jet printer (12), and the processor (42, 42A) is configured to: perform third conversion which is conversion from the signal value of the image data to the first chromaticity value through another color profile (CP) other than the color profile (CP); and perform the first conversion which is conversion from the first chromaticity value to the signal value of the ink jet printer (12) through the color profile (CP).
  15. The system (100) according to claim 14, wherein the processor (42, 42A) is configured to: remove an achromatic color component from the image data before performing the third conversion.
  16. A color management method comprising: (A) causing an ink discharge device (14) to form a print pattern by discharging (i) a cyan specific ink composition C according to a C1 signal value, (ii) a magenta specific ink composition M according to an M1 signal value and (iii) a yellow specific ink composition Y according to a Y1 signal value, each of the specific ink compositions C, M, Y having respective amounts (a1, b1; a2, b2 ; a3, b3) of a liquid crystal compound and of a chiral compound, the C1 signal value, M1 signal value and Y1 signal value together constituting a second signal value; (B) from the amounts of the liquid crystal compound and the chiral compound in the specific ink compositions C, M, Y, determining the total amounts of the liquid crystal compound and the chiral compound in the print pattern formed by mixing the specific ink compositions; (C) associating the total amounts of the liquid crystal compound and the chiral compound in the in the print pattern with the second signal value; (D) measuring the color of the print pattern formed as a color chart using the specific ink compositions, so as to determine a chromaticity value of the color chart; (E) associating the total amounts of the liquid crystal compound and the chiral compound in the in the print pattern with the measured chromaticity value; and (F) repeating (A) to (E) in respect of multiple different second signal values having corresponding amounts of the liquid crystal compound and chiral compound, whereby a respective second chromaticity value is derived, and whereby a color profile (CP) is created therefrom in which each of the second chromaticity value and the second signal value is associated with amounts of the liquid crystal compound and the chiral compound; (G) performing conversion between a first signal value and a first chromaticity value through the color profile (CP).
  17. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the steps of the method of claim 16.

Description

1. Field of the Invention The present disclosure relates to a color management apparatus, a color management method, and a program. 2. Description of the Related Art Color management is widely performed between different devices such as a monitor and an ink jet printer. For example, in a case of obtaining a printed material by printing an image displayed on the monitor with the ink jet printer, the printed material has a color different from the image due to a difference in a color system. By appropriately performing color management, it is possible to obtain a printed material having a desired color. As a part of such color management, for example, conversion between a signal value of the ink jet printer and a chromaticity value is performed through a color profile in JP2005-064727A. The technique of the related art including JP2005-064727A relates to color management on the premise that a printed material is obtained using a pigment-based ink, such as cyan, yellow, magenta, and black, a dye-based ink, or the like. On the contrary, an ink composition (hereinafter, called "specific ink composition" in some cases) containing a liquid crystal compound and a chiral compound is different from the inks above in terms of a color development mechanism. In a case where the specific ink composition is used, a new color management apparatus is necessary. EP3383018A1 discloses an information processing system, print medium, and information processing device. A disclosed method enables determining the color characteristics of the print medium, and enables a printer to print according to the color characteristics of the print medium. An information processing system enables printing based on media properties information for a particular print medium by: dividing the ranges of values three parameters in the HSV color space, hue, saturation, and value, can take into multiple intervals; assigning an interval name to each interval; using a specific combination of the interval names for the three parameters as media properties information; using the media properties information to identify a particular piece in a media piece group dividing the HSV color space based on print medium dependency; and printing on the print medium based on the media properties information for the specific print medium. The present disclosure is devised in view of such circumstances. An object to be solved by an embodiment of the present disclosure is to provide a color management apparatus related to an ink composition containing a liquid crystal compound and a chiral compound. An object to be solved by another embodiment of the present disclosure is to provide a color management method related to the ink composition. An object to be solved by still another embodiment of the present disclosure is to provide a program for causing a computer to execute a color management process related to the ink composition. The present disclosure includes the following aspects. In one aspect of the invention, there is provided a system according to claim 1 of the appended claims. In an embodiment, the color profile is created under a condition in which the amounts of the liquid crystal compound and the chiral compound associated with the second chromaticity value and the amounts of the liquid crystal compound and the chiral compound associated with the second signal value are at least partially the same. In an embodiment, the processor is configured to: select one from a plurality of selective color profiles as the color profile. In an embodiment, the plurality of selective color profiles include at least two color profiles having color measurement conditions of the second chromaticity value different from each other. In an embodiment, at least one of an incidence angle of color measurement light or a light-receiving angle of reflected light is different between the color measurement conditions. In an embodiment, a background color of the color chart is different between the color measurement conditions. In an embodiment, the second chromaticity value includes chromaticity values of color charts formed of at least two ink compositions forming the color charts having maximum reflection wavelengths different from each other. In an embodiment, the color chart has a black background, and the second chromaticity value includes a value measured under a condition in which an incidence angle of color measurement light is 15° and a light-receiving angle of reflected light is 0°, in the color chart formed of one specific ink composition of the at least two specific ink compositions, the maximum reflection wavelength is 430 nm or less, and in the color chart formed of the other specific ink composition of the at least two specific ink compositions, the maximum reflection wavelength is 640 nm or less. In an embodiment, the second chromaticity value is determined through simulation. In an embodiment, the color profile defines a color hue circle consisting of the second chroma