Information processing apparatus, information processing method, and program

Abstract

To provide an information processing apparatus, an information processing method, and a program capable of enhancing accuracy of an amount of ink drop, and thereby, enhancing image quality.SOLUTION: An information processing apparatus according to the present invention includes: a measurement result obtaining unit configured to obtain a measurement result of an amount of ink drop discharged from one or more nozzles in response to receiving a signal for starting a restriction on a total amount; a creation unit configured to create a table used for converting a gradation value into the amount of ink drop based on the measurement result of the amount of ink drop; and a total amount restriction unit configured to restrict a total amount of ink drop corresponding to the gradation value using the table.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an information processing device, an information processing method, and a program. [Background technology]

[0002] Among total amount limiting means for image forming devices such as inkjet printers, methods have been developed that convert tone values ​​into ink droplet amounts before limiting the total amount (see Patent Documents 1 to 3, etc.). Summary of the Invention [Problem to be solved by the invention]

[0003] However, in the above method, the relationship between the tone value and the ink droplet amount is not linear, so if the total amount is restricted based on the tone value, less ink will be deposited than it should be.

[0004] The present invention has been made in view of the above, and has an object to provide an information processing device, an information processing method, and a program that can improve image quality. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems and achieve the object, the present invention comprises a measurement result acquisition unit that acquires measurement results of the amount of ink droplets ejected from the nozzles when a signal to start total amount restriction is received, a creation unit that creates a table that converts gradation values ​​into the ink droplet amounts based on the measurement results of the ink droplet amounts, and a total amount restriction unit that uses the table to perform total amount restriction on the ink droplet amounts corresponding to the gradation values. [Effects of the Invention]

[0006] The present invention provides an effect of improving image quality. [Brief explanation of the drawings]

[0007] [Figure 1]FIG. 1 is a diagram showing an example of the relationship between the gradation value and the ink droplet amount. [Figure 2] FIG. 2 is a diagram for explaining an example of the ink droplet amount when the total amount is restricted by the gradation value. [Figure 3] FIG. 3 is a diagram for explaining an example of the ink droplet amount when the total amount is restricted after the tone value is converted into the ink droplet amount. [Figure 4] FIG. 4 is a diagram showing an example of the configuration of an image forming system according to the present embodiment. [Figure 5] FIG. 5 is a diagram for explaining an example of an outline of processing between the host computer and the information processing device in the image forming system according to the present embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of the configuration of a color conversion processing unit of the information processing device according to this embodiment. [Figure 7] FIG. 7 is a diagram showing an example of the configuration of the ink droplet volume measurement result acquisition unit of the information processing device according to this embodiment. [Figure 8] FIG. 8 is a diagram for explaining an example of a method for specifying the measurement gradation value and the number of measurements in the information processing device according to the present embodiment. [Figure 9] FIG. 9 is a diagram for explaining an example of displaying the ink change amount in the information processing device according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of an information processing device, an information processing method, and a program will be described in detail with reference to the accompanying drawings.

[0009] Figure 1 is a diagram showing an example of the relationship between gradation value and ink droplet volume. In Figure 1, the vertical axis represents ink droplet volume, and the horizontal axis represents gradation value. As shown in Figure 1, the relationship between gradation value and ink droplet volume is not linear, so if total volume control processing is performed using gradation value, less ink will be applied than it should be.

[0010] FIG. 2 is a diagram illustrating an example of ink droplet volume when total volume restriction is performed using gradation values. If total volume restriction is performed using gradation values ​​without conversion using ink droplet volume (for example, total volume restriction using a mixed color ink limit value of 160%), as shown in FIG. 2, the ink volume will be less than the amount that should be used. Here, the mixed color ink limit value is the sum of the ink limit values ​​for each of the CMYK colors. The ink limit value is also the ratio of the ink volume to the maximum ink volume.

[0011] FIG. 3 is a diagram illustrating an example of ink droplet volume when total volume restriction is applied after converting gradation values ​​to ink droplet volume. As shown in FIG. 3, it can be seen that a larger amount of ink can be applied to paper when total volume restriction is applied after converting to ink droplet volume compared to when total volume restriction is applied using gradation values. A small amount of ink narrows the color reproduction range. Therefore, as shown in FIG. 3, by converting to ink droplet volume and then restricting the total volume (for example, total volume restriction at 180 pL for ink volume corresponding to a mixed color ink limit value of 160%), it is possible to maximize the color reproduction range.

[0012] Patent Documents 1 and 2 describe a method for converting gradation values ​​into ink droplet volumes using a pre-stored table showing the relationship between gradation values ​​and ink droplet volumes. Patent Document 3 describes a method for converting gradation values ​​into ink droplet volumes using an LUT. In other words, both methods convert gradation values ​​into ink droplet volumes based on predetermined fixed values. However, the ink droplet volumes corresponding to gradation values ​​are not necessarily constant due to environmental factors such as temperature, humidity, and air pressure, as well as differences in the nozzles of inkjet heads during manufacturing and aging. A predetermined fixed value cannot accommodate these factors, resulting in discrepancies with the actual ink volume.

[0013] The difference between the ink droplet volume in the LUT and the actual ink volume directly affects image quality when restricting the total volume. The smaller the difference between the ink droplet volume and the actual ink volume, the greater the expansion of the color reproduction range, resulting in improved image quality. If the ink droplet volume is smaller than the actual ink volume, the total ink volume is restricted too much, resulting in a reduced color reproduction range. If the actual ink volume is greater than the ink droplet volume, excessive ink adheres to the paper, causing printer failure due to the paper being transported before the ink has dried, and image quality degradation due to bleeding and show-through. With prior art, image quality degrades due to insufficient ink droplet volume accuracy (the difference between the ink droplet volume and the actual ink volume).

[0014] 4 is a diagram showing an example of the configuration of an image forming system according to this embodiment. The image forming system according to this embodiment includes an information processing device 10, an image forming device 12, and a host computer 16. The host computer 16 and the image forming device 12 are connected to the information processing device 10 so as to be able to communicate with each other.

[0015] The information processing device 10 receives a drawing command for print data from the host computer 16, converts the data into a format that can be processed by the image forming device 12, and outputs the processed print data to the image forming device 12. A plurality of image forming devices 12 may be connected to the information processing device 10. Alternatively, the image forming device 12 may be directly connected to the host computer 16.

[0016] The information processing device 10 includes a CPU (Central Processing Unit) 10A, a ROM (Read Only Memory) 10B, a RAM (Random Access Memory) 10C, an engine interface 10D, a panel interface 10E, a host interface 10F, an HDD (Hard Disk Drive) 10H, and a UI unit 10J.

[0017] The CPU 10A executes control programs stored in the storage unit and controls the entire information processing device 10. The ROM 10B, RAM 10C, and HDD 10H are examples of the storage unit. The ROM 10B stores fixed programs. The RAM 10C has a storage area that serves as a work area for the CPU 10A. The HDD 10H stores various control programs, measurement data, conversion tables, etc.

[0018] The panel interface 10E is a connection interface with the UI unit 10J. The panel interface 10E displays a screen instructed by the CPU 10A on the UI unit 10J, and transmits an operation command received by the UI unit 10J to the CPU 10A.

[0019] The UI unit 10J (an example of a UI) has a display unit for a setting screen for performing various settings of the image forming apparatus 12, and an input receiving unit for receiving various setting inputs from the user.

[0020] The host interface 10F is connected to the host computer 16 for communication and receives drawing commands from the host computer 16.

[0021] The engine interface 10D outputs the converted print data to the image forming device 12 based on an output instruction from the CPU 10A.

[0022] The image forming device 12 includes an image forming unit. The image forming device 12 includes, for example, an electrophotographic or inkjet image forming unit. The image forming device 12 forms an image on a medium using the print data generated by the information processing device 10.

[0023] 5 is a diagram for explaining an example of an outline of processing between a host computer and an information processing device in an image forming system according to this embodiment. As an example, the host computer 16 has various applications 21 that generate document data 20. When the host computer 16 receives from a user a command to execute printing processing of the document data 20 generated by the application 21, the host computer 16 performs the necessary processing in the printer driver 22 and outputs a drawing command.

[0024] The information processing device 10 converts drawing commands received from the host computer 16 into print data that can be processed by the image forming device 12. Details of the color conversion processing unit 60 will be described later using FIG. 6. The rendering processing unit 61 converts the command-format data into raster-format image data and stores it in a buffer memory 62. The raster-format image data stored in the buffer memory 62 is output from a page memory 63 as print data.

[0025] 6 is a diagram showing an example of the configuration of a color conversion processing unit of an information processing device according to this embodiment. In this embodiment, color conversion processing unit 60 includes color conversion unit 60a, gamma conversion unit 60b, ink droplet volume measurement result acquisition unit 60c, total volume restriction unit 60d, and measurement gradation value measurement count input unit 60e.

[0026] The color conversion unit 60a performs color conversion processing on the color data of the drawing command received from the host computer 16. The gamma conversion unit 60b performs gamma conversion processing on the color data that has been subjected to color conversion processing by the color conversion unit 60a.

[0027] The measured gradation value measurement count input unit 60e acquires the measured gradation value and the number of measurements. In this embodiment, the measured gradation value measurement count input unit 60e may acquire the measured gradation value and the number of measurements input from the UI unit 10J.

[0028] The ink droplet volume measurement result acquisition unit 60c acquires ink droplet volume measurement results based on the color data that has undergone gamma conversion processing before total ink volume restriction, the measured gradation values ​​input by the measured gradation value measurement count input unit 60e, and the number of measurements. This allows for highly accurate ink droplet volume determination that accounts for environmental and aging changes. Upon receiving a signal to start total volume restriction, the ink droplet volume measurement result acquisition unit 60c instructs a measurement result acquisition unit included in the image forming device 12, etc., to measure the ink droplet volume and acquires the ink droplet volume measurement results.

[0029] The total amount restricting unit 60d (an example of a total amount restricting unit) uses a conversion table created by a conversion / reverse conversion table calculating unit 703 (see FIG. 7) described later to restrict the total amount of ink droplets corresponding to the gradation value.

[0030] The gradation processing unit 60f converts the ink droplet amount subjected to the total amount restriction into a gradation value. In this embodiment, the gradation processing unit 60f is provided outside the color conversion processing unit 60, but it may also be provided inside the color conversion processing unit 60.

[0031] 7 is a diagram showing an example of the configuration of the ink droplet volume measurement result acquisition unit 60c of the information processing device according to this embodiment. In this embodiment, as shown in FIG. 7, the ink droplet volume measurement result acquisition unit 60c includes a measurement condition determination unit 701, a measurement result acquisition unit 702, a conversion / reverse conversion table calculation unit 703, and a change amount calculation unit 704.

[0032] The measurement condition determination unit 701 acquires information on the measured gradation value and the number of measurements from the measured gradation value measurement number input unit 60e, and determines the measurement conditions.

[0033] Fig. 8 is a diagram for explaining an example of a method for specifying a measurement gradation value and the number of measurements in the information processing device according to this embodiment. The measurement gradation value to be measured and the number of measurements can be specified by the user on a UI displayed on UI unit 10J, as shown in Fig. 8. After the measurement gradation value is read from a file or specified directly, the measurement gradation value may be displayed for confirmation. Fig. 8 shows cases where 1, 10, 50, 100, 150, 200, 250, and 255 are specified as measurement gradation values.

[0034] Returning to FIG. 7, measurement result acquisition unit 702 (an example of a measurement result acquisition unit) acquires the measurement results of the ink droplet volume and sends the acquired measurement results (measurement data) of the ink droplet volume to conversion / reverse conversion table calculation unit 703, change amount calculation unit 704, and a storage unit (e.g., RAM 10C, HDD 10H). Here, possible methods for measuring the ink droplet volume include, for example, attaching a sensor or the like to the nozzles of the inkjet head of image forming apparatus 12 to detect the volume of ink droplets ejected from each nozzle, or ejecting ink into a tray containing a liquid that prevents the ink from evaporating and measuring its weight. In this embodiment, the measurement of the ink droplet volume is performed within image forming apparatus 12.

[0035] Furthermore, the measurement result acquisition unit 702 acquires the measurement results of the ink droplet volume at any gradation value between 1 and 255. Alternatively, the measurement result acquisition unit 702 may acquire the measurement results of the ink droplet volume for a gradation value to be measured that is specified on the UI unit 10J. This allows the user to select the balance between the time required to measure the ink droplet volume and accuracy. The gradation value to be measured may be specified, for example, by loading a text file in which the gradation values ​​are listed, separated by commas, tabs, spaces, etc., or by the user specifying the gradation value on the UI unit 10J.

[0036] Furthermore, the measurement result acquisition unit 702 may acquire the ink droplet volume measurement results for all nozzles used in printing. This makes it possible to reduce individual differences between nozzles and improve the accuracy of the ink droplet volume measurement results. Due to individual differences between inkjet heads or nozzles of inkjet heads, the amount of ink ejected is not necessarily the same for all nozzles even when the same gradation is output. Therefore, in order to take into account the variations in ink ejection volume between nozzles or inkjet heads, ink is ejected from all inkjet heads or all nozzles used in printing and the ink droplet volume is measured. This makes it possible to absorb the variations in ink ejection volume between nozzles or inkjet heads.

[0037] The measurement result acquisition unit 702 may also acquire the results of measuring the ink droplet volume multiple times. In this case, the measurement result acquisition unit 702 may acquire the results of measuring the ink droplet volume for the number of measurements specified on the UI unit 10J (the number of measurements included in the measurement conditions determined by the measurement condition determination unit 701). This allows the user to select the balance between the time required to measure the ink droplet volume and the accuracy.

[0038] The change amount calculation unit 704 calculates the difference from the previous measurement data and displays the result on a display unit such as the UI unit 10J.

[0039] 9 is a diagram illustrating an example of the display of the ink droplet amount change in the information processing device according to this embodiment. In this embodiment, after measuring the ink droplet amount, the change amount calculation unit 704 (an example of a display control unit) displays the ink droplet amount change, which is the difference between the current ink droplet amount measurement result and the previous ink droplet amount measurement result, on the UI unit 10J. This allows the user to actually feel the effect of measuring the ink droplet amount.

[0040] In this case, the change amount calculation unit 704 may display the color gamut before and after measuring the ink droplet volume so that the amount of ink change can be visually understood, or may indicate the amount of ink change for each color as a specific percentage. By notifying the user of the amount of ink change, the user can realize the effect of measuring the ink droplet volume. In addition, the measurement date and time of the previous measurement data and the current measurement data may be displayed.

[0041] Furthermore, the change amount calculation unit 704 may display a message on a display unit such as the UI unit 10J that determines the conditions for measuring the ink droplet volume in the future, based on the ink change amount. This can lead to future actions.

[0042] In this embodiment, the change amount calculation unit 704 displays a message on the UI unit 10J depending on the magnitude of the ink change amount and the amount of time that has elapsed since the measurement date and time of the previous measurement data. For example, the change amount calculation unit 704 displays a message with the content shown in Table 1 below on the UI unit 10J. The message shown in FIG. 9 is an example when the ink change amount is small and the amount of time that has elapsed since the measurement date and time of the previous measurement data is short. The user refers to the content of the message to determine future measurement frequency, measurement gradation value, number of measurements, etc. [Table 1]

[0043] The inverse conversion table calculation unit 703 (an example of a creation unit) creates a conversion table that converts gradation values ​​into ink amounts and an inverse conversion table that converts ink amounts into gradation values ​​based on the measurement data. These tables are used for total amount restriction by the total amount restriction unit 60d. Furthermore, when the measurement result acquisition unit 702 acquires multiple ink droplet amount measurement results, the inverse conversion table calculation unit 703 may create a conversion table based on the average value of the multiple ink droplet amount measurement results. This reduces ink droplet amount measurement errors and improves the accuracy of the ink droplet amount measurements.

[0044] If the conversion / inverse conversion table calculation unit 703 does not measure all gradation values ​​from 1 to 255, it interpolates between the gradation values ​​to create the conversion table and inverse conversion table. For example, if measurement results for gradation values ​​in increments of 5, such as 5, 10, 15, etc., are obtained, the conversion / inverse conversion table calculation unit 703 calculates the ink droplet volume by interpolation for the unmeasured gradation values ​​of 1, 2, 3, 4, 6, etc. Interpolation methods include linear interpolation and spline interpolation. The fewer gradation values ​​that are measured, the greater the risk of a larger difference between the actual ink droplet volume and the measured gradation values, but there is also the advantage that the measurement time is shorter. Which is more important can be selected depending on the situation.

[0045] In this way, according to the information processing device 10 of this embodiment, by actually measuring the ink droplet volume before the total volume restriction, it is possible to obtain a highly accurate ink droplet volume that corresponds to the environment and changes over time, thereby maximizing the improvement in image quality.

[0046] The program executed by the information processing device 10 of this embodiment is provided by being pre-installed in the ROM 10B etc. The program executed by the information processing device 10 of this embodiment may be provided by being recorded in an installable or executable file format on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disk).

[0047] Furthermore, the program executed by the information processing device 10 of the present embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Also, the program executed by the information processing device 10 of the present embodiment may be provided or distributed via a network such as the Internet.

[0048] The program executed by the information processing device 10 of this embodiment has a modular structure including the above-mentioned units (color conversion processing unit 60, rendering processing unit 61), and in actual hardware, an example of a processor such as CPU 10A reads and executes the program from the above-mentioned ROM 10B, thereby loading the above-mentioned units onto the main memory device, and the color conversion processing unit 60 and rendering processing unit 61 are generated on the main memory device.

[0049] For example, aspects of the present invention are as follows. <1> a measurement result acquisition unit that acquires a measurement result of the amount of ink droplets ejected from the nozzles when a signal to start total amount regulation is received; a creating unit that creates a table for converting a gradation value into the ink droplet volume based on the measurement result of the ink droplet volume; a total amount limiting unit that uses the table to limit the total amount of the ink droplets corresponding to the gradation value; An information processing device comprising: <2> the measurement result acquisition unit acquires the measurement results of the ink droplet volume for all of the nozzles used for printing; <1> The information processing device described in <3> the measurement result acquisition unit acquires the measurement result of the ink droplet volume for an arbitrary gradation value; <1> or <2> The information processing device described in <4> the measurement result acquisition unit acquires a plurality of measurements of the ink droplet volume, the creation unit creates the table based on an average value of a plurality of measurements of the ink droplet volume. <1> from <3> 10. The information processing device according to claim 9, wherein <5> the measurement result acquisition unit acquires the measurement result of the ink droplet volume for a gradation value to be measured that is designated on a UI. <1> or <2> The information processing device described in <6> the measurement result acquisition unit acquires the ink droplet volume measurement results for the number of measurements specified on a UI. <1> from <3> 10. The information processing device according to claim 9, wherein <7> a display control unit that displays, on a display unit, an amount of change in ink between the current ink droplet volume measurement result and the previous ink droplet volume measurement result after measuring the ink droplet volume; <1> from <6> 10. The information processing device according to claim 9, wherein <8> the display control unit displays a message on the display unit that determines a measurement condition for the ink droplet volume in the future based on the change in the ink droplet volume. <7> The information processing device described in <9> An information processing method executed by an information processing device, acquiring a measurement result of the amount of ink droplets ejected from the nozzles when a signal to start total amount regulation is received; creating a table for converting gradation values ​​into ink droplet volumes based on the measurement results of the ink droplet volumes; using the table to restrict the total amount of the ink droplets corresponding to the gradation value; An information processing method, including: <10> Computer, a measurement result acquisition unit that acquires a measurement result of the amount of ink droplets ejected from the nozzles when a signal to start total amount regulation is received; a creating unit that creates a table for converting a gradation value into the ink droplet volume based on the measurement result of the ink droplet volume; a total amount limiting unit that uses the table to limit the total amount of the ink droplets corresponding to the gradation value; A program to make it function as such. [Explanation of symbols]

[0050] 10. Information processing equipment 10A CPU 10B ROM 10C RAM 10D Engine Interface 10E Panel Interface 10F Host Interface 10H HDD 10J UI Department 60 Color conversion processing section 60a Color conversion unit 60b γ conversion section 60c Ink droplet volume measurement result acquisition unit 60d Total volume control section 60e Measurement gradation value measurement count input section 60f Gradation Processing Unit 701 Measurement condition determination unit 702 Measurement result acquisition section 703 Conversion and Reverse Conversion Table Calculation Unit 704 Change amount calculation unit [Prior art documents] [Patent documents]

[0051] [Patent Document 1] Japanese Patent Application Publication No. 2023-064459 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-009480 [Patent Document 3] Patent No. 5863407

Claims

1. a measurement result acquisition unit that acquires a measurement result of the amount of ink droplets ejected from the nozzles when a signal to start total amount regulation is received; a creating unit that creates a table for converting gradation values ​​into ink droplet volumes based on the measurement results of the ink droplet volumes; a total amount limiting unit that uses the table to limit the total amount of the ink droplets corresponding to the gradation value; An information processing device comprising:

2. The information processing apparatus according to claim 1 , wherein the measurement result acquisition unit acquires the measurement results of the ink droplet volume for all of the nozzles used in printing.

3. The information processing apparatus according to claim 1 , wherein the measurement result acquisition unit acquires the measurement result of the ink droplet volume for an arbitrary gradation value.

4. the measurement result acquisition unit acquires a plurality of measurements of the ink droplet volume, The information processing apparatus according to claim 1 , wherein the creation section creates the table based on an average value of the ink droplet volume measurements taken multiple times.

5. The information processing apparatus according to claim 1 , wherein the measurement result acquisition unit acquires the measurement result of the ink droplet volume for a tone value to be measured that is designated on a UI.

6. The information processing apparatus according to claim 1 , wherein the measurement result acquisition unit acquires the ink droplet volume measurement results for a number of measurements specified on a UI.

7. The information processing apparatus according to claim 1 , further comprising: a display control unit that, after measuring the ink droplet volume, displays on a display unit an amount of change in ink between the current ink droplet volume measurement result and the previous ink droplet volume measurement result.

8. The information processing apparatus according to claim 7 , wherein the display control unit displays a message on the display unit that determines a condition for measuring the ink droplet volume from now on, based on the amount of change in ink.

9. An information processing method executed by an information processing device, acquiring a measurement result of the amount of ink droplets ejected from the nozzles when a signal to start total amount regulation is received; creating a table for converting gradation values ​​into ink droplet volumes based on the measurement results of the ink droplet volumes; using the table to restrict the total amount of ink droplets corresponding to the gradation value; An information processing method, including:

10. Computer, a measurement result acquisition unit that acquires a measurement result of the amount of ink droplets ejected from the nozzles when a signal to start total amount regulation is received; a creating unit that creates a table for converting a gradation value into the ink droplet volume based on the measurement result of the ink droplet volume; a total amount limiting unit that uses the table to limit the total amount of the ink droplets corresponding to the gradation value; A program to make it function as such.

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