Program and Information Processing Device

Abstract

To enhance the reproductivity of the hue of an image of a printed matter to be displayed on a screen compared with a case in which characteristics of paper of absorbing a specific wavelength component is not considered.SOLUTION: A program is provided, which causes a computer for reproducing the hue of a printed matter to display the hue on a screen before printing to achieve a function for acquiring a density value of a color material that develops color by absorbing a specific wavelength component and characteristics of paper related to the absorption of the specific wavelength component, and a function for displaying an image obtained by reproducing the hue of the printed matter on the basis of the density value and the characteristics of the paper.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a program and an information processing apparatus.

Background Art

[0002] Before printing, the color tone of the image to be printed may be confirmed on the screen. A preview function is used for this confirmation. By confirming the color tone before printing, waste of paper and coloring materials can be reduced. In the field of color printing, four colors of C (cyan), M (magenta), Y (yellow), and K (black) are used as basic colors. These days, fluorescent colors are sometimes used in addition to the basic colors. When fluorescent colors are used, it becomes possible to reproduce brighter colors than when printing with only the basic colors. [[ID=]15]

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A toner corresponding to a fluorescent color (hereinafter also referred to as "fluorescent toner") is a coloring material that absorbs ultraviolet light and emits color. By the way, absorption of ultraviolet light occurs not only when it is incident from the surface side of the fluorescent toner but also when it is incident from the lower surface side. Incidence from the lower surface side is caused by incidence of ultraviolet light reflected by the paper or other toner layers located below the fluorescent toner.

[0005] Therefore, when the amount of ultraviolet light absorbed by the paper used for printing is large, the amount of ultraviolet light incident from the lower surface side of the fluorescent toner becomes smaller than when printing on paper with a small amount of ultraviolet light absorption. As a result, the vividness of the reproduced color deteriorates. However, previous preview functions did not take into account the paper characteristics that reduce the color development of fluorescent toner. As a result, there is a difference between the appearance of the actual printed material and the image displayed on the screen (hereinafter also referred to as the "preview image").

[0006] The present invention aims to improve the color reproduction of printed images displayed on a screen compared to cases where the properties of paper that absorb specific wavelength components are not taken into consideration. [Means for solving the problem]

[0007] The invention described in claim 1 relates to a computer that reproduces the colors of a printed material and displays them on a screen before printing, ultraviolet light The density value of the colorant that develops color upon absorption, and ultraviolet light This program provides a function to acquire the characteristics of the paper regarding absorption, and a function to display an image that reproduces the color of the printed material based on the density value and the characteristics of the paper. Claim 2 The invention described herein has a processor, and the processor is ultraviolet light The concentration value of the colorant excited by absorption, and ultraviolet light This is an information processing device that acquires the characteristics of the paper regarding absorption and displays an image that reproduces the color of the printed material based on the density value and the characteristics of the paper. The invention described in claim 3 relates to a computer that reproduces the color of a printed material before printing and displays it on a screen, by absorbing specific wavelength components. Exciting fluorescent color The density value of the colorant, Exciting fluorescent colors This program provides a function to acquire the characteristics of the paper regarding the absorption of a specific wavelength component, and a function to display an image that reproduces the color of the printed material based on the density value and the characteristics of the paper. The invention described in claim 4 is that the specific wavelength component has a wavelength Green wavelength A short light component, claim 3 This is the program described in [the document]. The invention described in claim 5 is characterized in that the paper has the property of reflecting light of the specific wavelength component incident on the surface of the paper, 3This is the program described in [the document]. The invention described in claim 6 is that the function to be acquired is to acquire the characteristics of the paper through the designation of the paper brand. 3 This is the program described in [the document]. The invention described in claim 7 is that the function to be obtained reads the characteristics of the paper from a table that links the characteristics of the paper with respect to the absorption of a specific wavelength component with the brand name of the paper. 6 This is the program described in [the document]. The invention described in claim 8 is that the function to acquire the value specified by the user through an input screen is acquired as a characteristic of the paper, 3 This is the program described in [the document]. The invention described in claim 9 is that the function to be acquired is to acquire the blue component value of an image of the paper used for printing as a characteristic of the paper, 3 This is the program described in [the document]. The invention described in claim 10 is a function for displaying an image, wherein the first pixel value representing the color of the colorant is corrected to a value smaller than the second pixel value when the colorant is printed on a reference paper with low absorption of the specific wavelength component. 3 This is the program described in [the document]. The invention described in claim 11 is a function for displaying an image, wherein the second pixel value is corrected to the first pixel value according to the properties of the paper surface that reflect light of a specific wavelength component incident on the surface of the paper. 10 This is the program described in [the document]. The invention described in claim 12 is a function for displaying an image, wherein the second pixel value is corrected to the first pixel value according to the characteristics of the paper associated with the brand name of the paper. 10 This is the program described in [the document]. The invention described in claim 13 is that the function for displaying the image corrects the second pixel value to the first pixel value according to the characteristics of the paper specified by the user through an input screen. 10 This is the program described in [the document]. The invention according to claim 14 is a program according to claim 10 where the function of displaying the image corrects the second pixel value to the first pixel value using the blue component value of the image obtained by imaging the paper used for printing. The invention according to claim 15 has a processor, and the processor Fluorescent colors obtains the concentration value of the coloring material excited by the absorption of a specific wavelength component and Exciting fluorescent colors the characteristics of the paper regarding the absorption of the specific wavelength component, and displays an image that reproduces the color tone of the printed matter based on the concentration value and the characteristics of the paper.

Advantages of the Invention

[0008] Claim 1 According to the described invention, it is possible to reproduce the appearance of the color tone of an image of a printed matter using fluorescent colors. According to the invention described in claim 2, it is possible to reproduce the appearance of the colors of an image in a printed material using fluorescent colors. Claim 3 According to the described invention, it is possible to enhance the reproducibility of the color tone of an image of a printed matter displayed on a screen as compared to the case where the characteristics of the paper that absorbs a specific wavelength component are not considered. Claim 4 According to the described invention, it is possible to reproduce the appearance of the color tone of an image of a printed matter using a coloring material that develops color with a light component having a short wavelength. Claim 5 According to the described invention, it is possible to adjust the color tone of an image of a printed matter displayed on a screen according to the magnitude of the characteristics regarding reflection. Claim 6 According to the described invention, it is possible to adjust the color tone of an image of a printed matter displayed on a screen only by specifying the brand of the paper. Claim 7 According to the described invention, if it is a brand recorded in the table, it is possible to adjust the color tone of an image of a printed matter displayed on a screen only by specifying the brand of the paper. Claim 8 According to the described invention, even when the characteristics regarding the absorption of a specific wavelength component are unknown, it is possible to adjust the color tone of an image of a printed matter displayed on a screen. Claim 9According to the described invention, even when the characteristics regarding the absorption of specific wavelength components are unknown, the color tone of the printed matter image displayed on the screen can be adjusted. Claim 10 According to the described invention, when the paper used for printing absorbs specific wavelength components used for the color development of the coloring material, it can be made smaller compared to the pixel value in the case of printing on the reference paper. Claim 11 According to the described invention, the magnitude of the pixel value can be adjusted according to the characteristics of reflecting light of specific wavelength components. Claim 12 According to the described invention, the magnitude of the pixel value can be adjusted according to the characteristics of the paper specified by the brand of the paper. Claim 13 According to the described invention, the magnitude of the pixel value can be adjusted according to the characteristics of the paper input by the user. Claim 14 According to the described invention, the magnitude of the pixel value can be adjusted according to the blue value of the image obtained by imaging the paper. Claim 15 According to the described invention, the reproducibility of the color tone of the printed matter image displayed on the screen can be enhanced compared to the case where the characteristics of the paper that absorbs specific wavelength components are not considered.

Brief Description of the Drawings

[0009] [Figure 1] It is a diagram showing a configuration example of the printing system used in the embodiment. [Figure 2] It is a diagram showing an example of the hardware configuration of the control device. [Figure 3] It is a diagram for explaining an example of the data structure of the white DLUT. [Figure 4] It is a diagram showing an example of the functional configuration of the control device. [Figure 5]This diagram illustrates the mechanism of color recognition and the calculation algorithm of the colored paper DLUT. (A) is a diagram illustrating how white paper looks, (B) is a diagram illustrating how the color of a part printed with yellow toner on the surface of white paper looks, (C) is a diagram illustrating how blue paper looks, (D) is a diagram illustrating how the color of a part printed with yellow toner on the surface of blue paper looks, and (E) is the calculation algorithm of the colored paper DLUT assuming printing on blue paper using basic colors. [Figure 6] This diagram illustrates the reflectivity of red paper at different wavelengths. [Figure 7] This diagram illustrates the principle of color development using fluorescent toner. (A) shows the amount of fluorescence excitation when fluorescent pink toner is printed on white paper, and (B) shows the amount of fluorescence excitation when fluorescent pink toner is printed on red paper. [Figure 8] This diagram illustrates the calculation formula for the colored paper DLUT used to display preview images when printing on non-white paper using basic and fluorescent colors. [Figure 9] This flowchart shows an example of the processing operation related to the display of a preview image by the control device. [Figure 10] This diagram illustrates examples of preview images when fluorescent colors are not used. (A) shows an example of a preview image when printing on white paper with basic colors, and (B) shows an example of a preview image when printing on blue paper with basic colors. [Figure 11] This diagram illustrates examples of preview images when using fluorescent colors. (A) shows an example of a preview image when printing on white paper using fluorescent pink toner, and (B) shows an example of a preview image when printing on red paper using fluorescent pink toner. [Figure 12] This diagram illustrates an example of a user specifying the ultraviolet light reflectance, which is a characteristic of the paper. (A) shows an example of the operation screen, and (B) shows the calculation formula for the colored paper DLUT used in Embodiment 2. [Figure 13]This diagram illustrates an example of specifying the paper characteristics necessary for calculating the colored DLUT component corresponding to the excitation wavelength by specifying the paper brand. (A) shows an example of the operation screen, and (B) shows an example of a data table linking paper brands and paper characteristics. [Figure 14] This figure illustrates the calculation formula for the colored paper DLUT used in Embodiment 3. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings. <Embodiment 1> <System Configuration> Figure 1 shows an example of the configuration of the printing system 1 used in the embodiment. The printing system 1 shown in Figure 1 consists of a paper feeder 10, a printing device 20, a post-processing device 30, and a control device 40. In this context, printing system 1 is an example of an image forming system, printing device 20 is an example of an image forming device, and control device 40 is an example of an information processing device.

[0011] The printing system 1 shown in Figure 1 is also called a production printer. However, printing system 1 is not limited to a production printer; it can also be a printer used in an office or a printer used at home. Office printers have functions such as scanning and sending / receiving faxes in addition to printing. The main difference between office printers and home printers is their performance.

[0012] The printing system 1 shown in Figure 1 has two paper feeders 10 connected in series. The paper feeder 10 is a device that supplies paper to the printing device 20. In this embodiment, the paper feeder 10 contains cut sheets of paper. For example, the paper feeder 10 can hold 7,000 sheets of cut paper. However, the paper stored in the paper feeder 10 is not limited to cut sheets; roll paper may also be used. In this embodiment, the paper is not limited to so-called white paper (hereinafter also referred to as "white paper"), but the use of colored paper (hereinafter referred to as "non-white paper") is also considered. The blank sheet of paper shown here is an example of a standard sheet.

[0013] In this embodiment, a non-blank sheet of paper is not limited to cases where the entire sheet is a single color. For example, the sheet may contain multiple colors. Furthermore, non-white paper includes not only dyed paper but also paper with color applied only to the surface. Therefore, paper with color applied to the printed surface or the layer beneath it may also be included in the broader definition of non-white paper. The paper used here is an example of a recording medium.

[0014] The printing system 1 shown in Figure 1 has two printing devices 20 connected in series. In this embodiment, each printing device 20 has an engine (hereinafter also referred to as "printing engine") that prints an image onto paper using an electrophotographic method. A printing engine prints an image onto paper through the processes of charging, exposure, development, transfer, and fixing. A printing engine is an example of a forming unit that uses multiple colorants to create an image on paper. Images include not only diagrams and photographs, but also text. Hereafter, the diagrams and photographs formed on the surface of the paper will also be referred to as objects.

[0015] The printing apparatus 20 used in this embodiment is capable of printing using four types of toner corresponding to basic colors and one or two types of toner corresponding to fluorescent colors. The toner corresponding to fluorescent colors will be referred to as fluorescent toner below. Fluorescent toners come in various fluorescent colors, including pink, yellow, and cyan. Fluorescent toners absorb ultraviolet light and emit excitation light with specific wavelengths. Because fluorescent colors are other than the basic colors, they are sometimes also called "special colors." The toner used in the printing device 20 is an example of a colorant. In this embodiment, the printing device 20 has the function of printing on one side of the paper as well as the function of printing on both sides of the paper. The paper on which the image has been printed is called a printed document.

[0016] The printing system 1 shown in Figure 1 has two post-processing units 30 connected in series. The post-processing units 30 are equipped with processes such as stacking (i.e., stacking), stapling, and binding.

[0017] The control device 40 is a device that controls the movement of the printing device 20 and other components. For example, the control device 40 controls the generation of DLUTs (Direct Look Up Tables), reading DLUTs, managing print jobs and document data used for printing, and RIP (Raster Image Processor) processing. DLUT is a table that maps the density values ​​of each toner color to the values ​​used to calculate each display color. DLUT is an example of a conversion table. Furthermore, the control device 40 also controls the generation of a preview image that reproduces the color of the printed material before printing, using the DLUT described above. In Figure 1, the control device 40 is located on top of the housing of the printing device 20, but it may also be located inside the housing of the printing device 20.

[0018] A print job refers to a job that instructs the printing of a document. A single print job includes a data file (hereinafter also referred to as "document data") corresponding to the document to be printed. The data format of the document data is not restricted. Document data includes electronic documents generated by application programs (hereinafter referred to as "apps") and digitized documents generated from paper documents.

[0019] Electronic documents include, for example, electronic data generated by so-called office applications, electronic data generated by drafting applications, electronic data generated by accounting applications, and web pages displayed in applications for viewing websites (i.e., browsers). Digitized documents include, for example, electronic data output from scanners and electronic data output from cameras.

[0020] The document data in this embodiment includes objects such as shapes and text, and each object has a color assigned to it. The color of an object is given by the density values ​​of, for example, C (cyan), M (magenta), Y (yellow), K (black), and fluorescent colors. In this embodiment, fluorescent pink is assumed as the fluorescent color. In this embodiment, the concentration value is expressed as, for example, 0 to 100%, or 0 to 255. 0% or 0 represents the minimum concentration value, and 100% or 255 represents the maximum concentration value.

[0021] <Control device configuration> Figure 2 shows an example of the hardware configuration of the control device 40. The control device 40 shown in Figure 2 includes a processor 41, a ROM (Read Only Memory) 42 in which the BIOS (Basic Input Output System) and other data are stored, a RAM (Random Access Memory) 43 used as the work area of ​​the processor 41, an auxiliary storage device 44, a user interface 45, a communication interface 46, and an I / O 47. The various parts of the control device 40 are connected via buses and other signal lines 48.

[0022] The processor 41 is a device that performs various functions through the execution of a program. In this embodiment, the processor 41 realizes various functions through program execution. The processor 41, ROM 42, and RAM 43 function as a computer. The auxiliary storage device 44 is, for example, a hard disk drive or semiconductor storage. The auxiliary storage device 44 is used to store programs, print jobs, etc. The term "program" is used as a general term for OS (Operating System) and application programs.

[0023] In addition, the auxiliary storage device 44 stores a DLUT (hereinafter referred to as "white DLUT") 44A that converts the density values ​​of each color provided by the document data into the display colors that would be observed if printed on white paper. Figure 3 illustrates an example of the data structure of the white DLUT44A. The left column of the data structure corresponds to the density values ​​specified in the document data, and the right column corresponds to the values ​​used to calculate the display color.

[0024] In Figure 3, the density values ​​are given by C (cyan), M (magenta), Y (yellow), K (black), and fluorescent colors. On the other hand, the values ​​used to calculate the display value are given by the R (red), G (green), and B (blue) gradation values ​​and the gloss level. The gradation values ​​are sometimes called "signal values." The gradation values ​​are expressed, for example, from 0 to 255. 0 is the minimum value and 255 is the maximum value. The gloss level is expressed, for example, from 0 to 100%. 0% is the minimum value and 100% is the maximum value. In Figure 3, specific numerical values ​​have been omitted.

[0025] Let's return to the explanation of Figure 2. The user interface 45 is an interface that accepts operations from a user using the printing device 20. The user interface 45 has an input section, such as operation buttons or a touch sensor that detects operations by the user's fingertips, and a display section, such as a liquid crystal display or an organic EL (=Electro-Luminescent) display.

[0026] The communication interface 46 is an interface for communicating with other terminals, etc. Wired or wireless communication methods can be used for the communication interface 46. Communication standards such as Ethernet® and Wi-Fi® can be used for the communication interface 46. I / O47 is a device used for communication between the processor 41 and the printing device 20 (see Figure 1), etc.

[0027] Figure 4 shows an example of the functional configuration of the control device 40. The functional units shown in Figure 4 are realized through the execution of a program by the processor 41 (see Figure 2). The functional units shown in Figure 4 can be broadly classified into an input receiving unit 410, an image processing unit 420, and an output unit 430.

[0028] The input receiving unit 410 is a functional unit that receives information necessary for predicting the color of printed materials. In Figure 4, the input receiving unit 410 receives input of document data 411, toner color 412, and paper color 413. The document data 411 is, for example, a color chart in which multiple colors with different hues are arranged in a matrix. The toner color 412 indicates the color of the toner that the printing device 20 can use as a colorant. The toner color 412 is given by, for example, C (cyan), M (magenta), Y (yellow), K (black), and a fluorescent color. In this embodiment, fluorescent pink is used as the fluorescent color. The paper color 413 is the color of the paper stored in the paper feeder 10 (see Figure 1), and is given by, for example, the density values ​​of C (cyan), M (magenta), Y (yellow), and K (black).

[0029] The image processing unit 420 is a functional unit that generates a preview image to predict the color of the printed material. In Figure 4, the image processing unit 420 consists of a preview image creation unit 421 and a white DLUT 44A. The preview image creation unit 421 is a functional unit that creates a color conversion table (hereinafter referred to as "color paper DLUT") that reproduces the colors observed when printing an object on a non-white surface, and creates a preview image.

[0030] In this embodiment, the preview image creation unit 421 creates a colored DLUT using document data 411, toner color 412, paper color 413, and white DLUT 44A. The created colored paper DLUT is stored in the auxiliary storage device 44 (see Figure 2). The preview image creation unit 421 creates a preview image by referencing a blank DLUT and a colored DLUT, converting the colors of the objects specified in the document data 411 to colors that reproduce how they would appear when printed on non-blank paper.

[0031] The output unit 430 is a functional unit that displays a preview image on the display unit to predict the color of the printed material. In Figure 4, the output unit 430 is composed of a preview unit 431. The preview unit 431 displays the preview image created by the preview image creation unit 421 on the display unit. In this embodiment, the preview image is displayed in three dimensions.

[0032] <Calculation algorithm for colored paper DLUT> The calculation algorithm for colored paper DLUT will be explained below using Figures 5 to 8. Figure 5 illustrates the mechanism by which colors are recognized and the calculation algorithm of the colored paper DLUT. (A) is a diagram illustrating how white paper looks, (B) is a diagram illustrating how the color of the area printed with yellow toner on the surface of white paper looks, (C) is a diagram illustrating how blue paper looks, (D) is a diagram illustrating how the color of the area printed with yellow toner on the surface of blue paper looks, and (E) is the calculation algorithm of the colored paper DLUT assuming printing on blue paper using basic colors.

[0033] In Figures 5(A) to (D), the incident and reflected R (red), G (green), and B (blue) light, as natural light, are represented by arrows. A downward-pointing arrow indicates incident light, and an upward-pointing arrow indicates reflected light. The length of the arrow represents the intensity of the light. In Figure 5(A), the intensity of the light component incident on the white paper is almost the same as the intensity of the light component reflected by the white paper. Therefore, R (red), G (green), and B (blue) are mixed together, making it appear white.

[0034] Incidentally, the B (blue) component is absorbed by the yellow toner. Therefore, in Figure 5(B), only the intensity of the reflected light component of B (blue) is reduced. As a result, the R (red) and G (green) components are mixed together, making it appear yellow. In Figure 5, the difference in the amount of absorbed components is represented by the size of the circles. On the other hand, in Figure 5(C), only the B (blue) component is reflected by the blue paper at the same level as the incident light component, while some of the R (red) and G (green) components are absorbed by the blue paper. As shown in Figure 5(C), the reflected light from the blue paper is predominantly B (blue). Consequently, the blue paper appears blue.

[0035] Furthermore, the red (R) component is absorbed more by blue paper than the green (G) component. Therefore, in Figure 5(C), the circle representing the absorption of the red (R) component is larger than the circle representing the absorption of the green (G) component, and the length of the arrow representing the intensity of reflected light is shorter for the red (R) component than for the green (G) component. Figure 5(D) illustrates the mechanism by which printing yellow toner on blue paper results in a greenish appearance. As shown in Figure 5(D), absorption occurs for the R (red) and G (green) components as explained in Figure 5(C), and absorption occurs for the B (blue) component as explained in Figure 5(B). As a result, the component of the reflected light that passes through the yellow toner and is output to the outside becomes predominantly green (G). This is why it appears greenish.

[0036] Figure 5(E) shows the calculation formula for the colored paper DLUT used to display the preview image when printing on non-white paper using basic colors. Colored paper DLUT[RGB] = Colored paper[RGB] × Blank paper DLUT[RGB] / Blank paper[RGB] Colored paper [RGB] is the signal value that gives the display color of colored paper used for printing, i.e., non-white paper, and is given as an RGB value. White paper [RGB] is the signal value that gives the display color when printing on white paper, and is given as an RGB value.

[0037] When using blank paper for printing, the same value appears in both the numerator and denominator, resulting in a formula consisting only of "Blank Paper DLUT[RGB]". The value in the denominator is used to normalize the effect of absorption on non-white paper as a relative value to white paper. In Figure 5(E), [RGB] corresponds to the display colors R (red), G (green), and B (blue) of the preview image.

[0038] Figure 6 illustrates the reflectance of red paper at different wavelengths. The vertical axis represents reflectance, and the horizontal axis represents the wavelength of light. Reflectance is an example of the paper's property of reflecting light of a specific wavelength. Incidentally, the law of conservation of energy applies to the reflection and absorption of specific wavelengths by paper. Therefore, in other words, reflectance is also an example of the paper's property of absorbing light of a specific wavelength. In Figure 6, the horizontal axis is arranged from shortest to longest wavelength as follows: UV (ultraviolet wavelength), B (blue wavelength), G (green wavelength), and R (red wavelength). That is, UV (ultraviolet wavelength) is the shortest wavelength light component, and B (blue wavelength) is the next shortest wavelength light component.

[0039] Figure 6 shows the reflectance of red paper (hereinafter referred to as "red paper") at different wavelengths as a curve. The reflectance is low for UV (ultraviolet wavelength), B (blue wavelength), and G (green wavelength), while the reflectance is high for R (red wavelength). In other words, red paper reflects less ultraviolet light. Furthermore, according to the law of conservation of energy, high reflectivity means low absorptivity, and conversely, low reflectivity means high absorptivity.

[0040] Figure 7 illustrates the principle of color development using fluorescent toner. (A) shows the amount of fluorescence excitation when fluorescent pink toner is printed on white paper, and (B) shows the amount of fluorescence excitation when fluorescent pink toner is printed on red paper. In Figures 7(A) and (B), the incident and reflected R (red), G (green), and B (blue) light, representing natural light, are also shown by arrows. The downward-pointing arrow indicates incident light, and the upward-pointing arrow indicates reflected light. The length of the arrow represents the intensity of the light.

[0041] Figure 7(A) shows the light component that passes through the fluorescent pink toner and enters the white paper, and the light component that passes through the fluorescent pink toner as reflected light from the white paper and is output to the outside. In Figure 7(A), the intensity of the incident and reflected red (R) light is approximately the same. The green (G) light component is absorbed significantly by the fluorescent pink toner. Therefore, the intensity of the reflected green (G) light is roughly half that of the incident light. The blue (B) light component is also absorbed by the fluorescent pink toner, but the amount absorbed is less than that of the green (G) light component. For this reason, in Figure 7(A), the intensity of the reflected blue (B) light is depicted as greater than that of the reflected green (G) light.

[0042] By the way, in Figure 7(A), ultraviolet light is treated as B (blue) and the reflected light is depicted accordingly. In other words, the intensity of the incident and reflected ultraviolet light is considered to be the same as the intensity of B (blue). In this case, the fluorescent pink toner generates highly intense excitation light through the absorption of both incident and reflected ultraviolet light. Since the excitation light is pink, in Figure 7(A), an arrow indicating the excitation light is added to the tip of the arrow indicating the R (red) reflected light. In other words, the R (red) component output from the paper side is increased compared to when fluorescent pink toner is not used. As a result, the fluorescence appears stronger.

[0043] In Figure 7(B), the intensity of the R (red) component reflected by the red paper and output to the outside is equivalent to the intensity of the incident light. The intensity of the G (green) component reflected by the red paper and output to the outside is lower than when reflected by white paper. The intensity of the B (blue) component reflected by the red paper and output to the outside is even lower than when reflected by white paper. In the example in Figure 7(B), the intensity of the reflected B (blue) light is about one-third of that of the incident light.

[0044] However, in Figure 7(B), only the incident light component is assumed to contribute to the generation of excitation light. Therefore, in Figure 7(B), excitation light is generated by the absorption of the incident light (B, blue). The intensity of this excitation light is smaller than that of the blank paper. Consequently, in Figure 7(B), the length of the arrow indicating the excitation light added to the tip of the arrow indicating the reflected light (R, red) is shorter. As a result, the fluorescence appears weaker.

[0045] Figure 8 illustrates the calculation formula for the colored paper DLUT used to display the preview image when printing on non-white paper using basic and fluorescent colors. In the case of Figure 8, we assume that fluorescent pink is printed on red paper. Therefore, if the combination of fluorescent color and paper color is different, it is necessary to swap the R, G, and B items in the calculation formula shown in Figure 8.

[0046] As mentioned earlier, when printing fluorescent pink toner on red paper, the excitation light increases the intensity of R (red), but is unrelated to the intensity of G (green) and B (blue). Therefore, the colored paper DLUT, which associates the density values ​​of each color used for printing with the values ​​used to calculate the displayed color, is divided into two parts: one for components that do not correspond to the excitation wavelength, and another for components that do correspond to the excitation wavelength.

[0047] <Calculation formula for colored paper DLUT of components not corresponding to the excitation wavelength> In this embodiment, the components corresponding to the excitation wavelength are G (green) and B (blue). Therefore, in this embodiment, the colored paper DLUT of the components corresponding to the excitation wavelength is colored paper DLUT[GB]. Colored paper DLUT[GB] is given by the following equation. Colored paper DLUT[GB] = Colored paper[GB] × Blank paper DLUT[GB] / Blank paper[GB]

[0048] Here, the colored paper [GB] represents the signal value of the color component that is not affected by the excitation light generated when printing fluorescent toner on non-white paper. In other words, it is the signal value of G (green) and B (blue). Blank paper [GB] represents the signal values ​​of the displayed colors when printing fluorescent toner on blank paper. In other words, it represents the signal values ​​of G (green) and B (blue). The blank DLUT [GB] is the G (green) and B (blue) portion of the DLUT, which converts the density values ​​of each color given by the document data into the display colors that would be observed if printed on white paper.

[0049] <Calculation formula for the DLUT of the colored paper corresponding to the excitation wavelength> In this embodiment, the component corresponding to the excitation wavelength is R (red). Therefore, the DLUT color paper for R (red) will be described below. Colored paper DLUT[R] corresponding to the excitation wavelength =Colored paper[R] × Blank paper DLUT[R] / Blank paper[R]-A

[0050] Here, the colored paper [R] represents the signal value of the color component affected by the excitation light generated when printing fluorescent toner on non-white paper. In other words, it is the signal value of R (red). Blank [R] represents the signal value of the display color when printing fluorescent toner on blank paper. In other words, it is the signal value of R (red). The blank DLUT[R] is the R (red) portion of the DLUT, which converts the density values ​​of each color given by the document data into the display colors that would be observed if printed on white paper. The above components, except for the difference in color, use the same calculation formula as the components that do not correspond to the excitation wavelength. In this embodiment, the absorption of ultraviolet light by the non-white paper weakens the R (red) signal component. Therefore, the amount A, which would not normally be excited, is subtracted.

[0051] The "quantity A that does not normally cause excitation" here is given by the following equation. A = Signal increment (excitation) on blank paper × Ratio of colored paper that would not normally be excited × Colored paper [R] / Blank paper [R] Of these, the "signal increment (excitation component) for a blank slate" is given by the following equation.

[0052] Signal increment (excitation) on a blank sheet = Blank DLUT[R] - Blank DLUT[R(S=0)] The first item, blank DLUT[R], is the R (red) portion of the blank DLUT when using spot color S, which is fluorescent toner, for printing. The second term, blank DLUT[R(S=0)], is the R (red) portion of a blank DLUT when the spot color S, which is fluorescent toner, is not used for printing. Therefore, the difference between the first and second terms represents the signal value of the excitation light component by the fluorescent toner.

[0053] Furthermore, the "ratio that is not excited by colored paper" is given by the following equation. The ratio of colored paper that is not normally excited = 1 - (255 + colored paper [B]) / (255 + blank paper [B]) In the second term, the colored paper [B] represents the signal value for the colored paper B (blue), which is the display color that contributes to the generation of excitation light. This signal value corresponds to the reflected light of B (blue) in Figure 7(B). Note that 255 corresponds to the maximum amount of incident light. In other words, the numerator of the second term corresponds to the sum of the arrows for the incident light and the arrows for the reflected light in Figure 7(B).

[0054] The denominator of the second term represents the signal value on a white sheet of paper for color B (blue), which is the display color that contributes to the generation of excitation light. This signal value corresponds to the reflected light of B (blue) in Figure 7(A). Note that 255 corresponds to the maximum amount of incident light. In other words, the denominator of the second term corresponds to the sum of the arrows for the incident light and the arrows for the reflected light in Figure 7(A). Therefore, the value in the second term represents the proportion of the B (blue) component that contributes to the generation of excitation light, compared to printing on blank paper. For example, it represents "0.7". Therefore, by subtracting "0.7" from "1", the ratio of the decrease in the B (blue) component due to the use of red paper is calculated. As a result, a quantity A that would not normally be excited is calculated.

[0055] <Example of processing operation> Figure 9 is a flowchart showing an example of the processing operation related to the display of a preview image by the control device 40. In the figure, the symbol S represents a step. The processing operations shown in Figure 9 are controlled through the execution of a program by the processor 41 (see Figure 2). The processing operation shown in Figure 9 is initiated when the processor 41 receives a request, for example, to display a preview image that reproduces the colors of the printed material before printing.

[0056] First, the processor 41 receives the document data, toner color, and paper color (Step 1). The toner color is the color of the toner that the printing device 20 (see Figure 1) can actually use. As mentioned above, toner colors include basic colors and spot colors. In this embodiment, fluorescent colors are assumed as spot colors. The paper color is the color of the paper used to print the document data. Next, processor 41 obtains a white DLUT (step 2).

[0057] Once the white DLUT is obtained, the processor 41 creates a colored DLUT (step 3). The colored DLUT can be calculated as shown in Figure 8. Next, the processor 41 uses a colored DLUT to convert the colors of the document data (step 4). Specifically, it converts the colors of the document data into red (R), green (G), and blue (B) gradation values ​​and gloss levels. Finally, the processor 41 displays a preview image created using the paper color received in step 1 and the signal value calculated in step 4 (step 5). In this embodiment, the preview image is displayed on the display unit of the control device 40.

[0058] <Example of preview image display> Figure 10 illustrates an example of a preview image when fluorescent colors are not used. (A) shows an example of a preview image when printing with basic colors on white paper, and (B) shows an example of a preview image when printing with basic colors on blue paper. Figures 10(A) and (B) show the same color chart printed on paper. In Figure 10(A), since the paper is white, the color of the color patch is reproduced almost exactly as the input value. Therefore, the color patch in the 3rd row and 4th column is displayed as yellow. However, when the paper is blue, as explained in Figure 5(D), the color patch in the 3rd row and 4th column is labeled as green in Figure 10(B).

[0059] Figure 11 illustrates examples of preview images when using fluorescent colors. (A) shows an example of a preview image when printing on white paper using fluorescent pink toner, and (B) shows an example of a preview image when printing on red paper using fluorescent pink toner. Figures 11(A) and (B) show the same color chart printed on paper. In Figure 11(A), although the paper is white, preview images with a strong fluorescent quality are displayed for all color patches. In Figure 11(B), the paper turns red, and the amount of ultraviolet light available for excitation of the fluorescent pink toner decreases compared to white paper. As a result, a preview image with weaker fluorescence is displayed.

[0060] <Summary> As explained above, this embodiment focuses on the characteristic that when fluorescent toner is printed on paper that absorbs a large amount of ultraviolet light, the excitation light generated by the fluorescent toner decreases, resulting in a weaker fluorescence. In this embodiment, we focus on the B (blue) component, which has a wavelength close to ultraviolet light, and propose calculation formulas for calculating DLUT for the component corresponding to the excitation light from the fluorescent toner and the component that does not correspond to it. As a result, when printing document data images using fluorescent colors on non-blank paper, it becomes possible to generate preview images that closely resemble the colors actually observed.

[0061] <Embodiment 2> This embodiment describes other examples of generating colored paper DLUTs. Note that the configuration of printing system 1 (see Figure 1) and the hardware and functional configuration of the printing device 20 that constitutes printing system 1 are the same as in Embodiment 1. Figure 12 illustrates an example in which the user specifies the ultraviolet light reflectance α, which is a characteristic of the paper. (A) shows an example of the operation screen, and (B) shows the calculation formula for the colored paper DLUT used in Embodiment 2.

[0062] Figure 12(A) shows an example of an operation screen displayed on the display unit of the user interface 45. The operation screen shown in Figure 12(A) is an example of an input screen. The operation screen shown in Figure 12(A) displays the title 451, "Setting the ultraviolet light reflectance α". Furthermore, the user is instructed to perform action 452, which states, "Please specify the reflectance α as a value between 0 and 1." In the case of Figure 12(A), the reflectance of ultraviolet light on a blank sheet of paper, which serves as the reference paper, is set to "1." Here, "1" is the maximum value. In other words, the reflectance α of a non-blank sheet is given as a relative value to the reflectance of ultraviolet light on a blank sheet of paper.

[0063] In Figure 12(A), the reflectance α is specified using slider bar 453. The bar-shaped area corresponding to slider bar 453 displays values ​​from "0" to "1". The reflectance α can be specified by moving slider 453A left or right using the mouse cursor or other controls. In Figure 12(A), a numerical field 454 is provided, displaying the value corresponding to the position of slider 453A. In this case, the value "0.6" is displayed. When button 455 is operated, the specified value is confirmed.

[0064] Figure 12(B) illustrates the calculation formula for the colored paper DLUT used to display the preview image when printing on non-white paper using basic and fluorescent colors. In the case of Figure 12, we assume that fluorescent pink is printed on red paper. Therefore, if the combination of fluorescent color and paper color is different, it is necessary to swap the R, G, and B items in the calculation formula shown in Figure 12.

[0065] <Calculation formula for colored paper DLUT of components not corresponding to the excitation wavelength> In this embodiment as well, fluorescent pink toner is used for printing. Therefore, the components that do not correspond to the excitation wavelength are G (green) and B (blue). Therefore, the colored DLUT for components that do not correspond to the excitation wavelength will be the same as the [GB] portion of the colored DLUT [RGB] explained in Figure 5(E). In other words, the value used to calculate the display color of the preview image linked to the density value of the document data is given by the following formula. Colored paper DLUT[GB] = Colored paper[GB] × Blank paper DLUT[GB] / Blank paper[GB] However, for blank paper [GB] and blank DLUT [GB], the signal values ​​used are those assumed to be for the maximum amount of excitation light.

[0066] <Calculation formula for the DLUT of the colored paper corresponding to the excitation wavelength> In this embodiment, the component corresponding to the excitation wavelength is R (red). Therefore, the colored DLUT corresponding to the excitation wavelength is colored DLUT[R]. As mentioned above, the amount of ultraviolet light available for excitation to fluorescent pink toner printed on red paper is less than the amount available for excitation to fluorescent pink toner printed on white paper. This is because the amount of ultraviolet light incident on the fluorescent pink toner from the surface side of the red paper is less than that on white paper.

[0067] Calculating the decrease in the total amount of ultraviolet light available for generating excitation light requires the calculations described in Embodiment 1. In this embodiment, we propose a simple method for calculating the colored DLUT of the component corresponding to the excitation wavelength. Specifically, the total amount of ultraviolet light available for generating excitation light when fluorescent toner is printed on blank paper is used as a reference value, and the total amount of ultraviolet light available for generating excitation light that decreases when fluorescent toner is printed on non-blank paper is given as a relative value to the reference value.

[0068] In the following, the reflectance α of a non-white paper is used as an example of a relative value. Here, the reflectance α of a non-white paper is normalized to a relative value where the reflectance α of a white paper is set to "1". The reduction in ultraviolet light due to the difference in reflectance α only affects the reduction of ultraviolet light incident on the fluorescent toner from the surface of the red paper. In this embodiment, however, it is used as an indicator to reduce the total amount of ultraviolet light that the fluorescent toner can use to generate excitation light. In this case, the colored paper DLUT[R] is given by the following formula: Colored paper DLUT[R] = (Colored paper[R] × Blank paper DLUT[R] / Blank paper[R]) × α

[0069] By using the colored paper DLUT created with this calculation formula, the R (red) signal value in the area where fluorescent pink toner is printed on red paper will be corrected to a smaller value than the R (red) signal value in the area where fluorescent pink toner is printed on white paper. Note that the "R (red) signal value of the area where fluorescent pink toner is printed on red paper" is an example of the first pixel value, and the "R (red) signal value of the area where fluorescent pink toner is printed on white paper" is an example of the second pixel value. White paper is an example of a standard paper that absorbs little ultraviolet light.

[0070] By the way, in this embodiment, the "reflectance α" of the paper is used as an indicator to reduce the total amount of ultraviolet light that can be used to generate excitation light, but other indicators that represent the "characteristic of reflecting ultraviolet light" may be used instead of "reflectance α". For example, a numerical value between 0 and 1 may be used to represent the ratio of the intensity of the reflected light with the R (red) excitation light component added in Figure 7(B) to the intensity of the reflected light with the R (red) excitation light component added in Figure 7(A). In this case, the value entered in Figure 12(A) will not be the reflectance α, but rather a value representing the "paper characteristics" or "reflection characteristics."

[0071] Alternatively, instead of reflectance α, absorptance β, which represents the property of non-white paper to absorb ultraviolet light, may be used. Absorptance β can be calculated using the law of conservation of energy, where β = 1 - α. The absorptive value β decreases as the reflectance α increases, and increases as the reflectance α decreases. The absorptive value β for blank paper is set to "1". When using absorption rate β, the colored paper DLUT[R] is defined by the following formula: Colored paper DLUT[R] = (Colored paper[R] × Blank paper DLUT[R] / (Blank paper[R]) × (1-β)

[0072] According to this formula, the larger the absorption rate β, the smaller the signal value of the component corresponding to the excitation wavelength. Conversely, the smaller the absorption rate β, the larger the signal value of the component corresponding to the excitation wavelength becomes, approaching the signal value of a blank slate.

[0073] Figure 12 illustrates the case where the user inputs numerical values ​​through the operation screen, but the numerical values ​​necessary for calculating the colored paper DLUT of the component corresponding to the excitation wavelength may also be specified by specifying the paper brand, etc. Figure 13 illustrates an example of specifying the paper characteristics necessary for calculating the colored DLUT component corresponding to the excitation wavelength by specifying the paper brand. (A) shows an example of the operation screen, and (B) shows an example of a data table linking paper brands and paper characteristics.

[0074] Figure 13(A) shows an example of an operation screen displayed on the display unit of the user interface 45. The operation screen shown in Figure 13(A) is an example of an input screen. The operation screen shown in Figure 13(A) displays the title "Specify Paper Type" (456). Additionally, the user is instructed to perform action 457, which is "Please specify the paper brand." Figure 13(A) displays a list 458 containing brand names and quality information, associated with checkboxes. Users can select a brand simply by checking the checkboxes, without needing to know the numerical values ​​of reflectivity α, absorption β, or other paper characteristics. When button 459 is pressed, the user's selection of the brand is confirmed.

[0075] The data table shown in Figure 13(B) links the characteristics of the paper to the brand name of the paper. The brand names registered in this data table are displayed on the operation screen shown in Figure 13(A). Furthermore, the characteristics of the paper include, for example, reflectance and other properties that reflect light of specific wavelength components, absorptiveness and other properties that absorb light of specific wavelength components, and an index that represents the decrease in the total amount of specific wavelengths that can be used to generate excitation light. In any case, the user only needs to specify the type of paper.

[0076] <Embodiment 3> In this embodiment, we will also describe other examples of generating colored paper DLUTs. Note that the configuration of printing system 1 (see Figure 1) and the hardware and functional configuration of the printing device 20 that constitutes printing system 1 are the same as in Embodiment 1. In this embodiment, the surface of a blank sheet of paper printed with fluorescent toner and the surface of a non-blank sheet are imaged in advance. From the image of the paper surface, the signal value of the B (blue) component, which is close to the ultraviolet wavelength that contributes to the generation of excitation light, is obtained from the captured image.

[0077] Obtaining the signal value of component B (blue) corresponds to obtaining the signal value of B (blue) in Figures 7(A) and 7(B). The signal value here is an example of the component value of B (blue). In this embodiment, the ratio of the B (blue) signal value obtained from the image corresponding to Figure 7(B) to the B (blue) signal value obtained from the image corresponding to Figure 7(A) is estimated to represent the characteristics of ultraviolet light reflected from the paper and output to the outside.

[0078] Figure 14 is a diagram illustrating the calculation formula for the colored paper DLUT used in Embodiment 3. The colored DLUT shown in Figure 14 is also generated by separating the component that does not correspond to the excitation wavelength from the component that does correspond to the excitation wavelength.

[0079] <Calculation formula for colored paper DLUT of components not corresponding to the excitation wavelength> In this embodiment as well, fluorescent pink toner is used for printing. Therefore, the components that do not correspond to the excitation wavelength are G (green) and B (blue). Therefore, the colored DLUT for components that do not correspond to the excitation wavelength will be the same as the colored DLUT [GB] explained in Figure 5(E). In other words, the value used to calculate the display color of the preview image linked to the density value of the document data is given by the following formula. Colored paper DLUT[GB] = Colored paper[GB] × Blank paper DLUT[GB] / Blank paper[GB]

[0080] <Calculation formula for the DLUT of the colored paper corresponding to the excitation wavelength> In this embodiment, the component corresponding to the excitation wavelength is R (red). Therefore, the colored DLUT corresponding to the excitation wavelength is colored DLUT[R]. As mentioned above, in this embodiment, the effect of ultraviolet light absorption by the paper is estimated using the signal value of the image with a B (blue) component that is close to the wavelength of ultraviolet light. In this case, the colored paper DLUT[R] is given by the following formula: Shikishi DLUT[R] =(Colored paper [R] × Blank DLUT [R] / Blank [R]) × Colored paper [B] / Blank [R]

[0081] In this formula, instead of the reflectance α in Embodiment 2, colored paper [B] / white paper [R] is used. As mentioned above, colored paper [B] / white paper [R] represents the ultraviolet light reflection characteristics of the paper used for printing. In this embodiment, it is necessary to capture images of a blank sheet of paper printed with fluorescent toner and an image of a non-blank sheet of paper printed with fluorescent toner. However, even when using paper with unknown properties such as reflectance α and absorption β, it becomes possible to reproduce with high accuracy how arbitrary document data would appear when printed on non-blank paper.

[0082] <Other Embodiments> (1) Although embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the embodiments described above. It is clear from the claims that embodiments with various modifications or improvements made to those described above are also included in the technical scope of the present invention.

[0083] (2) In the above-described embodiment, the control device 40 (see Figure 1) is located on top of the housing of the printing device 20 (see Figure 1), but it may also be implemented as an independent information processing device, such as a server, connected via a network or signal lines.

[0084] (3) In the embodiments described above, toner is given as an example of a fluorescent colorant, but the colorant may also be ink.

[0085] (4) In the embodiments described above, fluorescent toner was given as an example of a colorant that produces color by absorbing a specific wavelength component, but the specific wavelength component is not limited to ultraviolet wavelengths (UV).

[0086] (5) In the embodiments described above, paper having the property of absorbing ultraviolet wavelength components was referred to as non-white paper, but the technology described above can also be applied to white paper having the property of absorbing ultraviolet wavelength components.

[0087] (6) The processor in the embodiments described above refers to a processor in a broad sense, and includes not only general-purpose processors (e.g., CPUs) but also specialized processors (e.g., GPUs (=Graphical Processing Units), ASICs (=Application Specific Integrated Circuits), FPGAs (=Field Programmable Gate Arrays), programmable logic devices, etc.). Furthermore, the processor operations in each of the embodiments described above may be performed by a single processor alone, or by multiple processors located in physically separate locations working together. Also, the order in which each operation is executed by the processor is not limited to the order described in each of the embodiments described above, but may be changed individually. [Explanation of Symbols]

[0088] 1…Printing system, 10…Paper feeder, 20…Printing device, 30…Post-processing device, 40…Control device, 41…Processor, 44A…White DLUT, 410…Input reception unit, 411…Document data, 412…Toner color, 413…Paper color, 420…Image processing unit, 421…Preview image creation unit, 430…Output unit, 431…Preview unit

Claims

1. Before printing, a computer reproduces the colors of the printed material and displays them on the screen. A function to acquire the density value of a colorant that develops color upon absorption of ultraviolet light, and the characteristics of the paper related to the absorption of said ultraviolet light. A function to display an image that reproduces the color of the printed material based on the density value and the characteristics of the paper, A program to achieve this.

2. It has a processor, The aforementioned processor, The density value of the colorant excited by the absorption of ultraviolet light and the characteristics of the paper related to the absorption of said ultraviolet light are obtained. Based on the density value and the characteristics of the paper, an image is displayed that reproduces the color of the printed material. Information processing device.

3. Before printing, a computer reproduces the colors of the printed material and displays them on the screen. A function to acquire the concentration value of a colorant that excites a fluorescent color by absorbing a specific wavelength component, and the characteristics of the paper related to the absorption of that specific wavelength component that excites the fluorescent color, A function to display an image that reproduces the color of the printed material based on the density value and the characteristics of the paper, A program to achieve this.

4. The aforementioned specific wavelength component is a light component whose wavelength is shorter than the green wavelength. The program according to claim 3.

5. The characteristic of the paper is that it reflects light of a specific wavelength component incident on its surface. The program according to claim 3.

6. The aforementioned acquisition function acquires the characteristics of the paper by specifying the brand name of the paper. The program according to claim 3.

7. The function to acquire the above-mentioned characteristics of the paper is to read the characteristics of the paper from a table that links the characteristics of the paper with respect to the absorption of a specific wavelength component with the brand name of the paper. The program according to claim 6.

8. The aforementioned acquisition function acquires the value specified by the user through the input screen as the characteristics of the paper. The program according to claim 3.

9. The aforementioned acquisition function acquires the blue component value of an image of the paper used for printing as a characteristic of the paper. The program according to claim 3.

10. The function for displaying the aforementioned image corrects the first pixel value representing the color of the colorant to a value smaller than the second pixel value when the colorant is printed on a reference paper that has low absorption of a specific wavelength component. The program according to claim 3.

11. The function for displaying the image corrects the second pixel value to the first pixel value according to the properties of the paper surface that reflect light of a specific wavelength component incident on it. The program according to claim 10.

12. The function for displaying the aforementioned image corrects the second pixel value to the first pixel value based on the characteristics of the paper associated with the paper brand. The program according to claim 10.

13. The function for displaying the aforementioned image corrects the second pixel value to the first pixel value according to the paper characteristics specified by the user through the input screen. The program according to claim 10.

14. The function for displaying the aforementioned image corrects the second pixel value to the first pixel value using the blue component value of an image of the paper used for printing. The program according to claim 10.

15. It has a processor, The aforementioned processor, The concentration value of a colorant that excites a fluorescent color by absorbing a specific wavelength component, and the characteristics of the paper related to the absorption of that specific wavelength component that excites the fluorescent color are obtained. Based on the density value and the characteristics of the paper, an image is displayed that reproduces the color of the printed material. Information processing device.

Images