Color management device, color management method, and program

Abstract

The color management device comprises at least one processor. This processor performs conversion between a first signal value and a first chromaticity value using a color profile. This color profile is created using a second signal value and a second chromaticity value from a color chart formed from at least one ink composition comprising a liquid crystal compound and a chiral compound. The second chromaticity value and the second signal value are each associated with an amount of the liquid crystal compound and the chiral compound.

Description

[Technical Field]

[0001] This disclosure relates to a color management apparatus, a color management method, and a program. [Background technology]

[0002] Color management is widely practiced across different devices such as monitors and inkjet printers. For example, when printing an image displayed on a monitor using an inkjet printer, the printed material will have different colors from the original image due to differences in color systems. By properly performing color management, it is possible to obtain printed material with the desired colors. As part of such color management, for example, Patent Document 1 describes how a color profile is used to convert between the signal value and chromaticity value of an inkjet printer.

[0003] Patent Document 1: Japanese Unexamined Patent Publication No. 2005-064727 [Overview of the project] [Problems that the invention aims to solve]

[0004] Prior art, including Patent Document 1, relates to color management based on the premise of obtaining printed materials using pigment-based inks such as cyan, yellow, magenta, and black, as well as dye-based inks. In contrast, ink compositions containing liquid crystal compounds and chiral compounds (hereinafter sometimes referred to as "specific ink compositions") have a different color development mechanism than the above-mentioned inks. When specific ink compositions are used, a new color management device is required.

[0005] This disclosure has been made in view of the circumstances described herein. One embodiment of this disclosure aims to solve the problem of providing a color management apparatus relating to an ink composition containing a liquid crystal compound and a chiral compound. Other embodiments of this disclosure aim to solve by providing a color management method relating to the above-mentioned ink composition. Another embodiment of this disclosure aims to solve the problem of causing a computer to perform a color management process relating to the above-mentioned ink composition. [Means for solving the problem]

[0006] This disclosure includes the following aspects: <1> Includes at least one processor, The aforementioned processor performs a conversion between the first signal value and the first chromaticity value using a color profile. The aforementioned color profile is created using the second chromaticity value and the second signal value of a color chart formed from at least one ink composition containing a liquid crystal compound and a chiral compound. A color management device in which the second chromaticity value and the second signal value are each associated with the amounts of the liquid crystal compound and the chiral compound. <2> The color profile is created under the condition that at least a portion of the amounts of the liquid crystal compound and the chiral compound associated with the second chromaticity value are the same as the amounts of the liquid crystal compound and the chiral compound associated with the second signal value. <1> The color management device described in [reference]. <3> The processor selects one of a plurality of selective color profiles as the color profile. <1> or <2> The color management device described in [reference]. <4> The plurality of selective color profiles include at least two color profiles in which the colorimetric conditions for the second chromaticity value are different from each other. <3> The color management device described in [reference]. <5> In the above colorimetric conditions, at least one of the incident angle of the colorimetric light and the receiving angle of the reflected light is different. <4> The color management device described in [reference]. <6> Under the aforementioned colorimetric conditions, the background color of the color chart is different. <4> or <5> The color management device described in [reference]. <7> The second chromaticity value includes the chromaticity values of the color chart formed from at least two of the ink compositions that form color charts with different maximum reflection wavelengths, and the color management device according to any one of <1> to <6>. <8> The color chart has a black background, and the second chromaticity value includes those measured under the conditions that the incident angle of the colorimetric light is 15° and the light receiving angle of the reflected light is 0°. In the color chart formed from one of the at least two ink compositions, the maximum reflection wavelength is 430 nm or less. In the color chart formed from the other one of the at least two ink compositions, the maximum reflection wavelength is 640 nm or more, and the color management device according to <7>. <9> The second chromaticity value is determined by simulation, and the color management device according to any one of <1> to <8>. <10> The color profile defines a hue circle composed of the second chromaticity values of the color chart, and the hue circle does not include an achromatic region, and the color management device according to any one of <1> to <9>. <11> The color profile is a look-up table, and the color management device according to any one of <1> to <10>. <12> The processor performs conversion from the signal value of the image data to the signal value of the device through a first conversion that is the conversion between the first signal value and the first chromaticity value, and the color management device according to any one of <1> to <11>. <13> The device is a monitor. The first signal value is the signal value of the image data. The processor performs the first conversion that is the conversion from the signal value of the image data to the first chromaticity value according to the color profile. The color management device according to <12>, which performs a second conversion that is a conversion from the first chromaticity value to RGB signal values of the monitor according to the monitor profile of the monitor. <14> The device is an inkjet printer, The first chromaticity value is a signal value of the inkjet printer, The processor performs a third conversion that is a conversion from the signal value of the image data to the first chromaticity value according to another color profile other than the color profile, The color management device according to <12>, which performs the first conversion that is a conversion from the first chromaticity value to the signal value of the inkjet printer according to the color profile. <15> The processor removes an achromatic component from the image data before performing the third conversion. The color management device according to <14>. <16> including performing conversion between a first signal value and a first chromaticity value according to a color profile, The color profile is created using a second chromaticity value indicating a chromaticity value of a color chart formed from at least one ink composition containing a liquid crystal compound and a chiral compound, and a second signal value, Each of the second chromaticity value and the second signal value is associated with the amounts of the liquid crystal compound and the chiral compound. A color management method. <17> including performing conversion between a first signal value and a first chromaticity value according to a color profile, The color profile is created using a second chromaticity value of a color chart formed from at least one ink composition containing a liquid crystal compound and a chiral compound, and a second signal value, Each of the second chromaticity value and the second signal value is associated with the amounts of the liquid crystal compound and the chiral compound. A program for causing a computer to execute a color management process.

Advantages of the Invention

[0007] According to one embodiment of the present disclosure, a color management apparatus relating to an ink composition containing a liquid crystal compound and a chiral compound is provided. According to other embodiments of this disclosure, a color management method relating to the above-mentioned ink composition is provided. According to other embodiments of the present disclosure, a program is provided for causing a computer to perform a color management process relating to the above-mentioned ink composition. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram illustrating an example of the process from converting signal values ​​to chromaticity values ​​and obtaining printed materials. [Figure 2] Figure 2 is a schematic diagram showing an example of a color management system including a color management device. [Figure 3] Figure 3 is a block diagram showing an example of the hardware configuration of a color management device and an inkjet printer. [Figure 4] Figure 4 is a schematic diagram showing an example of the relationship between the selective reflection wavelength and the amounts of liquid crystal compounds and chiral compounds. [Figure 5] Figure 5 shows an example of a color profile. [Figure 6] Figure 6 is a schematic diagram illustrating an example of the procedure for creating a color profile. [Figure 7] Figure 7 shows an example of the relationship between CMY signal values ​​and the amounts of liquid crystal compounds and chiral compounds. [Figure 8] Figure 8 shows an example of the relationship between the amount of liquid crystal compounds and chiral compounds and the xyY chromaticity values. [Figure 9] Figure 9 is a block diagram showing an example of the functions of a CPU included in a color management device. [Figure 10] Figure 10 is a schematic diagram illustrating an example of the process from conversion of chromaticity values ​​to signal values ​​and obtaining a printed material. [Figure 11] Figure 11 is a block diagram showing an example of the functions of a CPU included in a color management device. [Figure 12] Figure 12 shows an example of CMY signal values ​​using a modified profile. [Figure 13] Figure 13 shows an example of CMY signal values ​​using a modified profile. [Figure 14] Figure 14 shows an example of CMY signal values ​​using a modified profile. [Modes for carrying out the invention]

[0009] The following describes the details of the color management device, color management method, and program related to this disclosure.

[0010] In this disclosure, CPU refers to the abbreviation for “Central Processing Unit.” NVM and is an abbreviation for “Non-volatile memory.” RAM stands for “Random Access Memory.” This refers to an abbreviation. FPGA stands for "Field-Programmable Gate Array." ☐ is an abbreviation for "Solid State Drive". HDD is an abbreviation for "Hard Disk Drive". EEPROM is an abbreviation for "Electrically Erasable and Programmable Read Only Memory". EL is an abbreviation for "Electro-Luminescence". I / F is an abbreviation for "Interface". DRAM is an abbreviation for "Dynamic Random Access Memory". SRAM is an abbreviation for "Static Random Access Memory". LAN is an abbreviation for "Local Area Network".

[0011] The drawings referenced in the following description are illustrative and schematic, and this disclosure is not limited to these drawings. The same reference numerals indicate the same components. Reference numerals in the drawings may be omitted.

[0012] <Color Management Device> [First Embodiment] In the first embodiment, the CMY signal value of the image data is a first chromaticity value (e.g., XYZ value, xyY value, L * a * b * This document describes an example of a color management device that converts values ​​(etc.). It also explains the process for obtaining a printed material with the desired color. The CMY signal value is an example of a first signal value.

[0013] As shown in Figure 1, in the first embodiment, the CMY signal values ​​of the image data are converted to first chromaticity values ​​by a color profile built into a color management device (not shown). The color profile is a color chart formed from at least one specific ink composition, with second chromaticity values ​​(e.g., XYZ values, xyY values, L) * a * b * The color profile is created using a second chromaticity value, which is associated with the amount (e.g., mass, volume, etc.) of the liquid crystal compound and the chiral compound, and a second signal value (e.g., CMY signal value), which is also associated with the amount of the liquid crystal compound and the chiral compound. The color profile associates the signal value with the chromaticity value. The color of a color chart is measured by placing a printed pattern formed on a transparent substrate onto a measuring platform. Therefore, the color of the color chart is determined by the overlap between the color of the printed pattern and the color of the measuring platform. For example, the color of the color chart will differ depending on whether the measuring platform is black or white, even if the color of the printed pattern is the same. In the following, the part of the measurement platform that overlaps with the color chart will be referred to as the "background."

[0014] The obtained first chromaticity value is converted to RGB signal values ​​by the monitor profile, and the image is displayed on the monitor using these RGB signal values. The image displayed on the monitor is a reproduction of the image of a printed material created using a specific ink composition when the CMY signal values ​​of the image data are output to an inkjet printer. The image displayed on the monitor in Figure 1 is an example of the display when the background is black. The black areas in the image displayed on the monitor in Figure 1 represent a black background.

[0015] The user checks the image of the printed material displayed on the monitor and adjusts the CMY signal values ​​to obtain the desired colors. Then, by outputting the adjusted CMY signal values ​​to the inkjet printer, a printed material with the desired colors is created. In another embodiment, if the user determines that the image of the printed material displayed on the monitor has the desired colors, the CMY signal values ​​can be output to the inkjet printer without adjustment.

[0016] The color management device of the first embodiment will be described in more detail below.

[0017] As shown in Figure 2, the color management device 10 is connected to the monitor 11, the inkjet printer 12, and the reception device 13. In this way, the color management device 10 is connected to the above devices to constitute the color management system 100.

[0018] The color management device 10 incorporates a computer 40 (see Figure 3) and controls the entire color management system 100.

[0019] The reception device 13 receives various instructions from the user using the color management device 10. Examples of the reception device 13 include a keyboard, mouse, touch panel, etc. The various instructions received by the reception device 13 are understood by the color management device 10. The monitor 11 displays various information (e.g., images, text, etc.) under the control of the color management device 10. Examples of the monitor 11 include a liquid crystal display or an EL display.

[0020] The inkjet printer 12 is connected to the color management device 10 via a communication network NT (e.g., the Internet, LAN, etc.) and operates under the control of the color management device 10. The connection method between the color management device 10 and the inkjet printer 12 may be a wired connection or a wireless connection.

[0021] As shown in Figure 3, the computer 40 has a CPU 42, an NVM 44, RAM 46, and a communication I / F 48. The CPU 42 is an example of a "processor" according to this disclosure.

[0022] The CPU 42, NVM 44, RAM 46, and communication I / F 48 are connected to bus 49. In the example shown in Figure 3, for illustrative purposes, a single bus is shown as bus 49, but there may be multiple buses. Bus 49 may be a serial bus or a parallel bus. A parallel bus includes a data bus, address bus, and control bus, etc.

[0023] NVM44 stores various types of data. Examples of NVM44 include various non-volatile storage devices such as EEPROM, SSDs, and HDDs. RAM46 temporarily stores various types of information and is used as work memory. Examples of RAM46 include DRAM and SRAM.

[0024] The NVM44 stores the program PG. The CPU42 reads the necessary program from the NVM44 and executes the read program PG on the RAM46. The CPU42 controls the entire color management system 100, including the color management device 10, by executing processing according to the program PG.

[0025] The communication interface 48 is an interface implemented by hardware resources such as an FPGA. The communication interface 48 is connected to the controller 15 of the inkjet printer 12 via the communication network NT, and exchanges various information between the CPU 42 and the controller 15.

[0026] A reception device 13 and a monitor 11 are also connected to the bus 49. The CPU 42 operates according to user instructions received by the reception device 13 and displays various information on the monitor 11.

[0027] The NVM44 stores a color profile CP for converting between a first signal value (CMY signal in the first embodiment) and a first chromaticity value. The color profile CP is created using a second chromaticity value of a color chart formed from at least one ink composition containing a liquid crystal compound and a chiral compound (i.e., a specific ink composition), and a second signal value associated with the amounts of the liquid crystal compound and the chiral compound. Each of the second chromaticity value and the second signal value is associated with the amounts of the liquid crystal compound and the chiral compound contained in the specific ink composition used to obtain the second chromaticity value. By using the color profile CP, the color management device 10 can output the color of a print pattern formed with the specific ink composition to the monitor 11 in response to a given first signal value input. In the example shown in Figure 3, the first signal value is the CMY signal value. The NVM44 stores the monitor profile MP of the monitor 11. The color profile CP can convert the first signal value to a first chromaticity value and convert the first chromaticity value to a first signal value.

[0028] The specific ink composition contains a liquid crystal compound and a chiral compound. By using the specific ink composition, a printed pattern having a selective reflection wavelength corresponding to the ratio of the liquid crystal compound and the chiral compound can be formed. The printed pattern has color derived from reflected light having a selective reflection wavelength and has a predetermined chromaticity value. The selective reflection wavelength is approximately 380 nm (purple to blue) to 830 nm (red). Two or more specific ink compositions capable of forming patterns with different selective reflection wavelengths may be used, preferably two types, and more preferably three types.

[0029] The “ratio of liquid crystal compounds and chiral compounds” refers to the ratio of the total amount of liquid crystal compounds and chiral compounds to the total amount of ink (hereinafter referred to as the “addition ratio”), the ratio of the amount of liquid crystal compounds to the total amount of liquid crystal compounds and chiral compounds (hereinafter also referred to as the “ratio of liquid crystal compounds”), or the ratio of the amount of chiral compounds to the total amount of liquid crystal compounds and chiral compounds. The amount can be, for example, mass, volume, etc. If the amount is mass, the addition ratio indicates the total mass of liquid crystal compounds and chiral compounds relative to the total mass of ink. If the amount is mass, the “ratio of liquid crystal compounds and chiral compounds” refers to the ratio of chiral compounds (mass%) or the ratio of liquid crystal compounds (mass%). The "selective reflection wavelength" refers to the average of the two wavelengths mentioned above, which are the wavelengths that exhibit the half-maximum transmittance: T1 / 2 (%), expressed by the following formula, when the wavelength is obtained by taking Tmin (%) as the minimum value of transmittance (maximum value of reflectance) in the object in question (e.g., printed pattern, background, etc.). Formula for calculating half-maximum transmittance: T1 / 2 = 100 - [(100 - Tmin)] ÷ 2

[0030] As shown in Figure 4, the helical pitch of the liquid crystal compound can be changed by varying the ratio of the liquid crystal compound and the chiral compound. Generally, the selective reflection wavelength becomes longer when the proportion of the liquid crystal compound is high, and shorter when the proportion of the liquid crystal compound is low. Therefore, by changing the selective reflection wavelength according to the ratio of the liquid crystal compound and the chiral compound, it is possible to obtain printed patterns with various chromaticity values. In this way, by changing the ratio of the liquid crystal compound and the chiral compound, the specific ink composition can exhibit various colors without the need for overcoating. For this reason, when using the specific ink composition, it is preferable that the printed pattern be a single layer.

[0031] As described above, the printed patterns formed from the specific ink composition exhibit coloration derived from reflected light with a selective reflection wavelength, and therefore do not show coloration in achromatic areas (black, gray, white, etc.).

[0032] The composition of the specific ink composition is not particularly limited as long as it contains a liquid crystal compound and a chiral compound. From the viewpoint of fixing the color of the printed pattern and improving printability, the liquid crystal compound is preferably polymerizable. Examples of specific ink compositions include those described in International Publication No. 2019 / 188846 (paragraphs 0020 to 0072) and International Publication No. 2021 / 059879 (paragraphs 0016 to 0077). An inkjet method can be suitably used as the printing method.

[0033] The inkjet printer 12 includes an ink ejector 14 and a controller 15. The ink ejector 14 has an ink cartridge 16C corresponding to the C signal, an ink cartridge 16M corresponding to the M signal, and an ink cartridge 16Y corresponding to the Y signal. Ink cartridges 16C, 16M, and 16Y each contain specific ink compositions C, M, and Y, respectively, which have different amounts of liquid crystal compounds and chiral compounds. Note that the colors of the print patterns formed from the specific ink compositions contained in ink cartridges 16C, 16M, and 16Y may differ from cyan (C), magenta (M), and yellow (Y), respectively. For convenience, the designation CMY is used to represent the specific ink compositions contained in the ink cartridges corresponding to the C signal, M signal, and Y signal, respectively.

[0034] The controller 15, under the control of the color management device 10, controls ink cartridges 16C, 16M, and 16Y to eject specific ink compositions C, M, and Y. At this time, amounts of specific ink compositions C, M, and Y corresponding to the CMY signal values ​​are ejected, and these ejected specific ink compositions are mixed. That is, amounts of liquid crystal compounds and chiral compounds corresponding to the CMY signal values ​​are ejected, and the ejected liquid crystal compounds and chiral compounds are mixed to form a printed pattern. The printed pattern has a chromaticity value associated with the amounts of liquid crystal compounds and chiral compounds. In this way, a printed pattern formed by mixing liquid crystal compounds and chiral compounds in amounts corresponding to the CMY signal values ​​can be obtained, and various chromaticity values ​​can be expressed.

[0035] As shown in Figure 5, the color profile CP includes CMY signal values ​​and chromaticity values ​​of the print pattern formed when these signal values ​​are input to the inkjet printer 12. Such a color profile CP is created, for example, as follows. In Figures 5 to 8, the CMY signal values ​​are examples of second signal values, and the chromaticity values ​​(xyY color system) are examples of second chromaticity values.

[0036] First, as shown in Figure 6, the relationship between the CMY signal values ​​and the amounts of specific ink composition C, specific ink composition M, and specific ink composition Y ejected from ink cartridges 16C, 16M, and 16Y, respectively, is determined. Depending on the C1 signal value, specific ink composition C is ejected from ink cartridge 16C. The ejected specific ink composition C contains a1[g] of a liquid crystal compound and b1[g] of a chiral compound. Depending on the M1 signal value, specific ink composition M is ejected from ink cartridge 16M. The ejected specific ink composition M contains a2[g] of a liquid crystal compound and b2[g] of a chiral compound. Depending on the Y1 signal value, specific ink composition Y is ejected from ink cartridge 16Y. The ejected specific ink composition Y contains a3[g] of a liquid crystal compound and b3[g] of a chiral compound. From the above amounts of liquid crystal compounds and chiral compounds, the amount of liquid crystal compounds (A1[g]=a1+a2+a3) and the amount of chiral compounds (B1[g]=b1+b2+b3) in the printed pattern formed by mixing specific ink compositions C to Y can be determined. From the above, it is possible to correlate the CMY signal values ​​with the amounts of liquid crystal compounds and chiral compounds. That is, the C1 signal value, M1 signal value, and Y1 signal value can be correlated with the amount of liquid crystal compounds in A1[g] and the amount of chiral compounds in B1[g].

[0037] Furthermore, as shown in Figure 6, the relationship between the amounts of liquid crystal compounds and chiral compounds and the chromaticity values ​​of the resulting printed pattern is determined. The printed pattern formed as described above (a color chart formed from a specific ink composition containing A1[g] of liquid crystal compound and B1[g] of chiral compound) is then colorimetrically measured. This allows, for example, the chromaticity values ​​(x1, y1, Y1) of the printed pattern in the xyY color system to be obtained. From the above, it is possible to correlate the amounts of liquid crystal compounds and chiral compounds with the chromaticity values. That is, the amounts of A1[g] of liquid crystal compound and B1[g] of chiral compound can be correlated with the chromaticity values ​​(x1, y1, Y1) in the xyY color system.

[0038] As described above, chromaticity values ​​of a color chart (printed pattern), which are associated with the amounts of liquid crystal compounds and chiral compounds, and CMY signal values ​​associated with the amounts of liquid crystal compounds and chiral compounds can be obtained. The CMY signal values ​​and chromaticity values ​​can then be linked through the amounts of liquid crystal compounds and chiral compounds. In other words, a color profile can be created using the CMY signal values ​​(C1 signal value, M1 signal value, Y1 signal value) and chromaticity values ​​(x1, y1, Y1).

[0039] When creating a color profile, as shown in Figure 7, the CMY signal values ​​are varied, and the amounts of liquid crystal compounds and chiral compounds corresponding to each CMY signal value are determined. As shown in Figure 8, the amounts of liquid crystal compounds and chiral compounds are varied, and the chromaticity values ​​corresponding to each amount are determined. This makes it possible to create color charts corresponding to various CMY signal values ​​and chromaticity values.

[0040] The method for linking chromaticity values ​​and CMY signal values ​​through the amounts of liquid crystal compounds and chiral compounds is not particularly limited. For example, the relationship between the amounts of liquid crystal compounds and chiral compounds and the chromaticity value can be fitted to a polynomial or the like to create a function, and then the relationship between the amounts of liquid crystal compounds and chiral compounds and the chromaticity value can be further fitted to a polynomial or the like to create a function. In this way, the chromaticity value and the CMY signal value can be linked via the amounts of liquid crystal compounds and chiral compounds. From the viewpoint of improving the conversion accuracy of color profiles, it is preferable that, for at least a portion of the amounts of a certain liquid crystal compound and chiral compound, there is a one-to-one correspondence between the chromaticity value of the color chart (printed pattern) and the signal value that outputs the amount of that liquid crystal compound and chiral compound. In other words, it is preferable that the color profile is created under the condition that at least a portion of the amounts of liquid crystal compound and chiral compound associated with the chromaticity value and the amounts of liquid crystal compound and chiral compound associated with the signal value are the same. This makes it possible to improve the accuracy of the correspondence between the chromaticity value and the signal value, compared to, for example, the case in which the relationship between the amount and the chromaticity value is made into a function as described above, and a color profile with higher conversion accuracy can be obtained. From the viewpoint of further improving the conversion accuracy of color profiles, it is preferable that the portion in which the amounts of liquid crystal compound and chiral compound associated with the chromaticity value and the amounts of liquid crystal compound and chiral compound associated with the signal value are the same is larger, and it is most preferable that they are all the same.

[0041] For example, in Figures 7 and 8, the amounts of liquid crystal compounds and chiral compounds are the same, and the relationship between CMY signal values ​​and chromaticity values ​​can be determined through these amounts, thus obtaining a color profile CP as shown in Figure 5. The color profile CP obtained in this way is a chromaticity value of a color chart formed from at least one specific ink composition containing liquid crystal compounds and chiral compounds, and is created using chromaticity values ​​associated with the amounts of liquid crystal compounds and chiral compounds, and signal values ​​associated with the amounts of liquid crystal compounds and chiral compounds.

[0042] The above describes one method of creating a color profile, but the method of creating a color profile is not limited to the above method, and color profiles can be created in various ways. For example, various color profiles can be created by selecting the color system of the chromaticity values ​​of the color chart, the maximum reflection wavelength and number of specific ink compositions, and the colorimetric conditions of the color chart. Furthermore, color profiles can also be created by simulating the chromaticity values ​​of the color chart.

[0043] The color system of the chromaticity values of the color chart is not particularly limited, and various color systems (for example, RGB color system, XYZ color system, xyY color system, L * a * b * color system, etc.) determined by the spectral wavelength and lightness can be mentioned.

[0044] In the present disclosure, the "chromaticity value" is a concept including lightness and chroma. For example, the chromaticity value in the xyY color system is (x, y, Y), and L * a * b * the chromaticity value in the color system is (L * , a * , b * ).

[0045] The second chromaticity value used for creating the color profile may include the chromaticity values of color charts formed from at least two specific ink compositions that form color charts with different maximum reflection wavelengths. The color profile shown in FIG. 5 was created using three specific ink compositions with different amounts of liquid crystal compound and chiral compound. The "maximum reflection wavelength" refers to the wavelength at which the reflectance is maximum when the reflection spectrum is measured in the range of 400 to 800 nm using an integrating sphere with an ultraviolet-visible near-infrared spectrophotometer V770 (JASCO).

[0046] As described above, various color profiles can be created by changing the color measurement conditions of the color chart.

[0047] For example, the color appearance of the printed pattern formed from a specific ink composition varies depending on the angle from which the printed pattern is observed. That is, the color appearance of the printed pattern has angle dependence. Therefore, when measuring the chromaticity value of the printed pattern using color measurement light, different color profiles including angle-dependent information can be created by changing at least one of the incident angle of the color measurement light and the light receiving angle of the reflected light.

[0048] The appearance of colors in printed patterns formed from specific ink compositions differs depending on the background color (i.e., the color of the substrate). In other words, the way colors are perceived in printed patterns is background-dependent. Therefore, when measuring the chromaticity value of a printed pattern using colorimetric light, it is possible to create different color profiles that include background color information by changing the background color of the printed pattern.

[0049] If the second chromaticity value includes the chromaticity value of a color chart formed from at least two ink compositions whose maximum reflected wavelengths are different from each other, For example, the color chart includes values ​​measured under conditions where the background is black, the incident angle of the colorimetric light is 15°, and the reception angle of the reflected light is 0°. In a color chart formed from one of at least two specific ink compositions, the maximum reflected wavelength is 430 nm or less. In a color chart formed from one of at least two specific ink compositions, the maximum reflected wavelength may be 640 nm or greater. By mixing two specific ink compositions with a large difference in maximum reflection wavelength, it becomes possible to express a variety of colors. In other words, it is possible to obtain a printed pattern with a desired maximum reflection wavelength within a wide range from maximum reflection wavelengths of 430 nm or less to maximum reflection wavelengths of 640 nm or more. By adjusting the chromaticity value (incident angle of colorimetric light 15°, reception angle of reflected light 0°) within this wide wavelength range, it is possible to obtain a printed material (with a black background) with the desired color.

[0050] The second chromaticity value of the color chart may be determined by simulation. For example, multiple color charts (i.e., print patterns) are prepared by varying the amounts of liquid crystal compounds and chiral compounds, and the spectral spectra of the color charts are obtained. Then, the spectral spectra are superimposed in arbitrary proportions (equivalent to mixing specific ink compositions) to calculate the chromaticity value in the desired color system. This makes it possible to simulate the chromaticity value of print patterns created using specific ink compositions containing liquid crystal compounds and chiral compounds in proportions that have not been measured. For example, by using an optical model, it is possible to simulate the angular dependence of chromaticity values, and it is also possible to simulate chromaticity values ​​when the background color is changed. As described above, a color profile can be created using the second chromaticity value of the color chart obtained through simulation.

[0051] As described above, printed patterns formed from specific ink compositions do not exhibit color in the achromatic region. Therefore, the color circle may be defined excluding the chromatic values ​​of the achromatic region. In other words, a color profile defines a color circle consisting of chromatic values ​​from a color chart, and the color circle does not need to include the achromatic region. This makes it possible to create a color profile with characteristics such as no color development in the achromatic region, and color development becoming stronger as one moves towards the high-saturation region.

[0052] A color profile can be a lookup table.

[0053] In the example shown in Figure 3, the NVM44 stores multiple selective color profiles CP. The multiple selective color profiles CP include at least two color profiles whose second chromaticity measurement conditions differ from each other. Specifically, the selective color profiles CP include color profiles CP in which at least one of the incident angle of the colorimetric light and the received angle of the reflected light differs in the measurement conditions, and color profiles CP in which the background color of the color chart differs.

[0054] As shown in Figure 9, multiple functional units are realized by the CPU 42 executing operations based on the program PG. The program PG causes the CPU 42 to function as an image data acquisition unit 50, a K signal removal unit 51, a conversion unit 52, a display control unit 53, an image data correction unit 54, and a print control unit 55.

[0055] The image data acquisition unit 50 acquires image data from an external device 17 (for example, an imaging device, an external storage device storing images, etc.). The image data is a CMYK signal value SG1, and the image data acquisition unit 50 stores the CMYK signal value SG1 in the NVM 44. In other embodiments, the image data may be an RGB signal value. The image data may be image data of an image created with drawing software.

[0056] The K signal removal unit 51 removes the K signal value from the CMYK signal value SG1 and outputs the CMY signal value SG2, which is stored in the NVM 44. In another embodiment, if the image data is an RGB signal value, the K signal removal unit may replace the R signal value, G signal value, and B signal value of the RGB signal value with the C signal value, M signal value, and Y signal value, respectively, and output the CMY signal value.

[0057] The conversion unit 52 performs a conversion from the CMY signal value SG2 to the chromaticity value CV1 as the first chromaticity value (i.e., the first conversion) using the color profile CP, and stores the chromaticity value CV1 in the NVM 44.

[0058] The conversion unit 52 performs a conversion from the chromaticity value CV1 to the RGB signal value SG3 (i.e., a second conversion) using the monitor profile MP, and stores the RGB signal value SG3 in the NVM 44.

[0059] The display control unit 53 outputs the RGB signal value SG3 to the monitor 11 and controls the display on the monitor 11 an image of the printed material obtained when an image is printed using specific ink composition C, specific ink composition M, and specific ink composition Y.

[0060] The color profile CP and monitor profile MP may constitute a device link profile. The device link profile may perform the conversion from CMY signal values ​​SG2 to RGB signal values.

[0061] The user checks the image of the printed material displayed on the monitor 11. As described above, the NVM 44 stores multiple selective color profiles CP (at least two color profiles with different colorimetric measurement conditions for chromaticity values). If necessary, the user can select any color profile CP from among the multiple selective color profiles CP that is different from the color profile used in the first conversion (i.e., change the color profile CP) to check the change in the color of the printed material image due to differences in viewing angle, background color, etc. By changing the color profile CP, the CMY signal value SG2 is converted to a chromaticity value different from the chromaticity value CV1 obtained in the first conversion. Accordingly, the color of the printed material image displayed on the monitor 11 changes.

[0062] The user identifies the area in the printed image where color correction is to be applied and inputs a color correction instruction (i.e., an instruction to change the color of the identified area) to the receiving device 13. The receiving device 13 outputs a correction instruction for the CMYK signal value SG2 to the image data correction unit 54.

[0063] The image data correction unit 54 corrects the CMY signal value SG2 according to the input correction instruction, outputs the corrected CMY signal value SG4, and stores it in the NVM 44. The corrected CMY signal value SG4 is displayed on the monitor 11 as an image of the printed material through conversion by the color profile CP and monitor profile MP, in the same manner as described above for the original CMY signal value SG2. For example, the image data correction unit 54 identifies the signal value of the pixel in the image of the printed material to be color corrected, and corrects the CMY signal value SG2 by changing the CMY signal value SG2 corresponding to the signal value of the pixel in response to the correction instruction.

[0064] The print control unit 55 outputs the corrected CMY signal value SG4 to the inkjet printer 12.

[0065] The controller 15 of the inkjet printer 12 controls ink cartridges 16C, 16M, and 16Y to eject specific ink composition C, specific ink composition M, and specific ink composition Y. This makes it possible to obtain printed materials with the desired color.

[0066] In the first embodiment, the conversion from CMY signal value SG2 to RGB signal value is performed using two profiles, color profile CP and monitor profile MP. Such a conversion is, for example, CMY signal value → xyY chromaticity value → RGB signal value. In another embodiment, three or more profiles may be combined to perform the conversion from CMY signal values ​​to RGB signal values. For example, by combining three profiles, CMY signal values ​​→ L * a * b * It is possible to perform a conversion from chromaticity value → xyY chromaticity value → RGB signal value. In other words, the first color profile converts the CMY signal value to L * a * b * Convert to chromaticity values, and then use the second color profile, L * a * b * The system performs a conversion from chromaticity values ​​to xyY chromaticity values, and then, using a third color profile, it can convert from xyY chromaticity values ​​to RGB signal values.

[0067] [Second Embodiment] In the second embodiment, an example of a color management device that converts chromaticity values ​​to CMY signal values ​​will be described. The process for obtaining printed materials will also be described.

[0068] As shown in Figure 10, in the second embodiment, the CMY signal values ​​of the image data before conversion are converted to a first chromaticity value using a different profile ("other profile" in Figure 10) than the color profile according to the first embodiment. The obtained first chromaticity value is converted to a CMY signal value using a color profile built into a color management device (not shown). Then, the obtained converted CMY signal value is output to an inkjet printer to create a printed material. The CMY value is an example of a first signal value.

[0069] The color management device of the second embodiment will be described in more detail below.

[0070] As an example where the CPU processing differs from that of the first embodiment, the second embodiment will be described below with reference to Figure 11. The configuration of the color management system 100A in the second embodiment is the same as that of the color management system 100 in the first embodiment, as shown in Figures 2 and 3. In Figure 11, the monitor 11 and the receiving device 13 are omitted.

[0071] As shown in Figure 11, multiple functional units are realized by the CPU 42A executing operations based on the program PG. The program PG causes the CPU 42A to function as an image data acquisition unit 50A, achromatic component removal unit 56, conversion unit 52A, and print control unit 55A. The image data acquisition unit 50A and the print control unit 55A are the same as the image data acquisition unit 50 and print control unit 55 described in the first embodiment.

[0072] The achromatic component removal unit 56 removes the achromatic component signal value from the CMYK signal value SG5 before performing the conversion by the color profile CP (i.e., the first conversion), outputs the CMY signal value SG6 after the achromatic component has been removed, and stores it in the NVM44A. In another embodiment, if the image data is an RGB signal value, the achromatic component removal unit replaces the R signal value, G signal value, and B signal value of the RGB signal value with the C signal value, M signal value, and Y signal value, respectively, and further removes the achromatic component signal value to output the CMY signal value after the achromatic component has been removed.

[0073] The conversion unit 52A performs a conversion (i.e., a third conversion) from the CMY signal value SG6 (CMY signal value before conversion) after the removal of achromatic components to the chromatic value CV2 as the first chromaticity value, using profile CPA, which is a different color profile from the color profile CP according to the first embodiment, and stores the chromaticity value CV2 in NVM44A. Profile CPA is an example of another color profile.

[0074] Furthermore, the conversion unit 52A performs a conversion from the chromaticity value CV2 to the CMY signal value SG7 (the converted CMY signal value) using the color profile CP according to the first embodiment (i.e., a first conversion), and stores the CMY signal value SG7 in the NVM44A. In this embodiment, the color profile CP functions as a printer profile. The CMY signal value SG7 is an example of a first signal value.

[0075] The color profile CP and profile CPA may constitute a device link profile. The device link profile may perform the conversion from the CMY signal value SG6 after achromatic component removal to the CMY signal value SG7.

[0076] The print control unit 55A outputs the corrected CMY signal value SG4 to the inkjet printer 12. This produces a printed document.

[0077] In the second embodiment, the conversion from CMY signal value SG5 to CMY signal value SG7 is performed using two profiles, color profile CP and profile CPA, according to the first embodiment. Such a conversion is, for example, a conversion via chromaticity value, which is CMY signal value → xyY chromaticity value → CMY signal value. In another embodiment, three or more profiles may be combined to perform a conversion from CMY signal value to CMY signal value via a conversion to chromaticity value. For example, by combining three profiles, CMY signal value → L * a * b *It is possible to perform a conversion from chromaticity value → xyY chromaticity value → CMY signal value. In other words, the first color profile converts the CMY signal value to L * a * b * Convert to chromaticity values, and then use the second color profile, L * a * b * The system can convert from chromaticity values ​​to xyY chromaticity values, and then, using a third color profile, convert from xyY chromaticity values ​​to CMY signal values.

[0078] [Differentiation] The modified example illustrates a process that directly converts the signal values ​​of image data into corrected signal values ​​after color correction.

[0079] As shown in Figures 12 to 14, one method is to convert the CMY signal values ​​of image data to corrected CMY signal values. This will be explained in more detail below.

[0080] In the first embodiment, as described above, the image data correction unit 54 corrects the CMY signal value SG2 in response to a correction instruction from the user and outputs the corrected CMY signal value SG4. In other words, the conversion from CMY signal value SG2 to CMY signal value SG4 is performed in response to a correction instruction from the user. For example, a correction profile (hereinafter sometimes simply referred to as "correction profile") that profiles the history of correction instructions from the user can be created, and the CMY signal value SG2 can be directly converted to the corrected CMY signal value SG4 using the correction profile. In one embodiment, it is also possible to create a correction profile that directly converts from the CMYK signal value SG1 to the corrected CMY signal value SG4.

[0081] For example, as described above, the image data correction unit 54 identifies the signal value of the pixel in the printed image where the color correction is to be applied, and corrects the CMY signal value SG2 by changing the CMY signal value SG2 corresponding to the signal value of the pixel in response to the correction instruction. Such corrections are patterned. That is, if there is a part in the printed image that shows a certain color, a correction profile is created that patterns how much the CMY signal value SG2 corresponding to the signal value of the pixel in that part is corrected. With such a correction profile, it is possible to convert from the CMY signal value SG2 to the corrected CMY signal value SG4. By incorporating a table for removing the K signal into the correction profile, it is possible to convert from the CMYK signal value SG1 to the corrected CMY signal value SG4.

[0082] The conversion described above is Method 1, which is an example of converting from CMY signal values ​​(which may be CMYK signal values ​​in some embodiments, and the same applies hereinafter) to modified CMY signal values, as shown in Figure 12.

[0083] In another embodiment, as shown in Method 2 in Figure 13, the modified profile allows L * a * b * A conversion from chromaticity value to xyY chromaticity value may be performed. In this case, an arbitrary profile can be used to convert the CMY signal value to L * a * b * Convert to chromaticity value, and then apply the correction profile, L * a * b * The chromaticity value is converted to xyY chromaticity value, and then, using a specified profile, the xyY chromaticity value is converted to the corrected CMY signal value. Through this series of steps, the CMY signal value is converted to the corrected CMY signal value.

[0084] In another embodiment, as shown in Method 3 in Figure 14, the conversion from CMY signal values ​​to xyY chromaticity values ​​may be performed using a correction profile. In this case, the conversion from CMY signal values ​​to xyY chromaticity values ​​is performed using a correction profile, and the conversion from xyY chromaticity values ​​to the corrected CMY signal values ​​is performed using an arbitrary profile. Through this series of steps, the conversion from CMY signal values ​​to corrected CMY signal values ​​is performed.

[0085] As the "optional profile" mentioned above, color management may be performed using the color profile relating to this disclosure and the color management device relating to this disclosure.

[0086] The first embodiment, the second embodiment, and modifications have been described above as examples of using CMY signal values, but this disclosure is not limited to cases where CMY signal values ​​are used. In one embodiment, in addition to the CMY signal, one or more signals other than the CMY signal values ​​may be used. In another embodiment, only one or two signals of the C signal, M signal, and Y signal may be used.

[0087] <Color Management Methods> The color management method relating to this disclosure is: The method includes converting between a first signal value and a first chromaticity value using a color profile created with a second chromaticity value of a color chart formed from at least one ink composition containing a liquid crystal compound and a chiral compound, the second chromaticity value being associated with the amounts of the liquid crystal compound and the chiral compound, and a second signal value also associated with the amounts of the liquid crystal compound and the chiral compound.

[0088] Each configuration of the information processing method is derived from the above-described configuration in the information processing device.

[0089] <Program> The program related to this disclosure is A color profile created using a second chromaticity value of a color chart formed from at least one ink composition containing a liquid crystal compound and a chiral compound, wherein the second chromaticity value is associated with the amount of liquid crystal compound and chiral compound, and the second signal value is associated with the amount of liquid crystal compound and chiral compound, is used to convert between a first signal value and a first chromaticity value. This is a program that causes a computer to perform color management processing, including [specific color management processes].

[0090] Each component of the program is derived from the above-described configuration in the color management device.

[0091] The descriptions and illustrations presented above are detailed explanations of the technical aspects of this disclosure and are merely examples of the technical aspects. For example, the above descriptions of the structure, function, operation, and effect are examples of the structure, function, operation, and effect of the technical aspects of this disclosure. Therefore, it goes without saying that you may delete unnecessary parts, add new elements, or replace elements in the descriptions and illustrations presented above, as long as you do not deviate from the essence of the technical aspects of this disclosure. In order to avoid confusion and facilitate understanding of the technical aspects of this disclosure, explanations of common technical knowledge and the like that do not require special explanation to enable the implementation of the technical aspects of this disclosure have been omitted from the descriptions and illustrations presented above.

[0092] All documents, patent applications, and technical standards described herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted as being incorporated by reference.

[0093] [Explanation of symbols] 10. Color Management System 11 monitors 12. Inkjet printers 13 Reception device 14. Ink ejection device 15 Controllers 16C, 16M, 16Y ink cartridges 40 Computers 42, 42A CPU 44, 44A N VM 46 RAM 48 Communication I / F 49 bus 50, 50A Image data acquisition unit 51 K signal removal section 52, 52A Conversion section 53 Display Control Unit 54 Image Data Correction Section 55, 55A Printing Control Unit 56. Achromatic component removal section 100, 100A Color Management System NT communication network PG Program CP Color Profile CPA Profile MP Monitor Profile SG1 CMYK signal value SG2 CMY signal value SG3 RGB signal values SG4 Corrected CMY signal values SG5 CMYK signal value SG6 CMY signal values ​​after removal of achromatic components SG7 CMY signal value CV1, CV2 chromaticity values

[0094] The disclosure of Japanese Patent Application No. 2021-132044, filed on 13 August 2021, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. It includes at least one processor, The aforementioned processor performs a conversion between the first signal value and the first chromaticity value based on the color profile. The aforementioned color profile is created using the second chromaticity value and the second signal value of a color chart formed from at least one ink composition containing a liquid crystal compound and a chiral compound. A color management device in which the second chromaticity value and the second signal value are each associated with the amounts of the liquid crystal compound and the chiral compound.

2. The color management apparatus according to claim 1, wherein the color profile is created under the condition that at least a portion of the amounts of the liquid crystal compound and the chiral compound associated with the second chromaticity value is the same as the amounts of the liquid crystal compound and the chiral compound associated with the second signal value.

3. The color management apparatus according to claim 1 or claim 2, wherein the processor selects one of a plurality of selective color profiles as the color profile.

4. The color management apparatus according to claim 3, wherein the plurality of selective color profiles include at least two color profiles in which the colorimetric conditions for the second chromaticity value are different from each other.

5. The color management apparatus according to claim 4, wherein, in the colorimetric conditions, at least one of the incident angle of the colorimetric light and the receiving angle of the reflected light is different.

6. The color management apparatus according to claim 4, wherein the background color of the color chart is different under the aforementioned color measurement conditions.

7. The color management apparatus according to claim 1 or 2, wherein the second chromaticity value includes the chromaticity value of the color chart formed from at least two ink compositions that form the color chart, the maximum reflection wavelengths of which are different from each other.

8. The aforementioned color chart has a black background, and the second chromaticity value includes values ​​measured under the conditions that the incident angle of the colorimetric light is 15° and the reception angle of the reflected light is 0°. In the color chart formed from one of the at least two ink compositions, the maximum reflection wavelength is 430 nm or less. The color management apparatus according to claim 7, wherein the color chart formed from one of the other ink compositions among the at least two ink compositions has a maximum reflected wavelength of 640 nm or more.

9. The color management apparatus according to claim 1 or claim 2, wherein the second chromaticity value is determined by simulation.

10. The color management apparatus according to claim 1 or claim 2, wherein the color profile defines a hue circle consisting of the second chromaticity values ​​of the color chart, and the hue circle does not include achromatic regions.

11. The color management apparatus according to claim 1 or claim 2, wherein the color profile is a lookup table.

12. The color management apparatus according to claim 1 or claim 2, wherein the processor performs a conversion from the signal value of image data to the signal value of a device via a first conversion, which is the conversion between the first signal value and the first chromaticity value.

13. The aforementioned device is a monitor, The first signal value is the signal value of the image data, The aforementioned processor, The color profile performs the first conversion, which is a conversion from the signal value of the image data to the first chromaticity value. The color management apparatus according to claim 12, wherein a second conversion is performed, which is a conversion from the first chromaticity value to the RGB signal value of the monitor, based on the monitor profile of the monitor.

14. The aforementioned device is an inkjet printer, The first chromaticity value is the signal value of the inkjet printer, The aforementioned processor, A third conversion is performed using a color profile other than the aforementioned color profile, which is a conversion from the signal value of the image data to the first chromaticity value. The color management apparatus according to claim 12, wherein the first conversion, which is the conversion from the first chromaticity value to the signal value of the inkjet printer, is performed using the color profile.

15. The color management apparatus according to claim 14, wherein the processor removes achromatic components from the image data before performing the third conversion.

16. This includes performing a conversion between the first signal value and the first chromaticity value using a color profile. The aforementioned color profile is created using a second chromaticity value, which indicates the chromaticity value of a color chart formed from at least one ink composition containing a liquid crystal compound and a chiral compound, and a second signal value. A color management method in which each of the second chromaticity value and the second signal value is associated with the amounts of the liquid crystal compound and the chiral compound.

17. This includes performing a conversion between the first signal value and the first chromaticity value using a color profile. The aforementioned color profile is created using the second chromaticity value and the second signal value of a color chart formed from at least one ink composition containing a liquid crystal compound and a chiral compound. A program for causing a computer to perform color management processing, wherein each of the second chromaticity value and the second signal value is associated with the amounts of the liquid crystal compound and the chiral compound.

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