Colorimetric system, colorimetric method, and control program

Abstract

The system appropriately determines whether color measurement by the colorimeter is necessary while minimizing resource consumption and system load. [Solution] The colorimeter 1000 includes an image colorimeter 18 that reads multiple patch images on paper arranged in the transport direction and width direction by moving a colorimeter in the width direction perpendicular to the paper transport direction and moving the paper in the transport direction, and performs color measurement; a paper information acquisition unit 17 that acquires paper information of the paper to be measured; a storage unit that stores the colorimeter information measured by the image colorimeter 18 as history data associated with the paper information; and a control unit that, when a color measurement instruction is received, determines whether or not color measurement by the image colorimeter is necessary based on the paper information of the paper to be measured and the history data.

Description

Technical Field

[0001] The present invention relates to a color measurement system, a color measurement method, and a control program.

Background Art

[0002] In an image forming system including an image forming apparatus and an image reading apparatus, in recent years, an image reading apparatus that performs a reading process of an image formed on a sheet (recording medium) by the image forming apparatus includes a scanner provided in a paper conveyance path for reading a color measurement patch on the paper, and a colorimeter provided in the paper conveyance path for measuring the color of the color measurement patch on the paper.

[0003] Patent Document 1 discloses an image forming apparatus equipped with a scanner capable of reading an entire image on a sheet and a colorimeter that is fixedly arranged to measure only a partial area (central portion in the width direction) of the paper surface. In this image forming apparatus, a color measurement patch composed of a common color is arranged by separating the reading area by the scanner and the color measurement area by the colorimeter, and the RGB (Red, Green, Blue) value read by the scanner is converted into L*a*b*, and this is corrected by the L*a*b* obtained by reading the color measurement patch of the same color with the colorimeter, thereby disclosing a technique (simple color measurement) for efficiently performing color measurement using a scanner.

[0004] Patent Document 2 discloses an image forming system equipped with a colorimeter that can perform color measurement of the entire paper by moving the colorimeter in a direction perpendicular to the paper conveyance direction and conveying the paper to scan the entire paper. In the image forming system disclosed in this Patent Document 2, a sheet on which a large number of patch images are formed by an upstream image forming unit is stopped at a measurement position, and multi-point color measurement is performed while moving the colorimeter in the width direction, and the process of moving the paper slightly in the conveyance direction and then performing multi-point color measurement again is repeated to achieve color measurement of the entire paper (high-precision color measurement).

[0005] When performing the above high-precision color measurement, a series of color measurement processes require about several tens of minutes. Therefore, constantly performing the high-precision colorimetric measurements described above would significantly reduce productivity. Patent Document 2 describes the following process to achieve both productivity and high-precision color management. In other words, the process begins with scanning using a scanner that can measure color in a short time. If the scan results detect a color variation exceeding a predetermined value, the image colorimeter performs high-precision color measurement across the entire sheet of paper. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2018-61099 [Patent Document 2] Japanese Patent Publication No. 2024-085279 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the image forming system described in Patent Document 2 has the problem that, when executing a job, it is always necessary to print an image for analysis by the scanner in order to determine whether or not color measurement by the image colorimeter is required, which increases the consumption of resources such as paper and toner. Furthermore, there is a problem in that the analysis process required to determine whether or not color measurement is necessary based on the scan results after scanning becomes a burden on the system.

[0008] This invention has been made in view of the above circumstances, and aims to appropriately determine whether or not color measurement by a colorimeter is necessary while suppressing resource consumption and system load. [Means for solving the problem]

[0009] The above objectives of the present invention are achieved by the following means.

[0010] (1) An image colorimeter unit that reads multiple patch images on paper arranged in the transport direction and the width direction by moving a colorimeter in the width direction perpendicular to the paper transport direction and moving the paper in the transport direction, and performs color measurement. A paper information acquisition unit that acquires paper information of the paper on which color measurement is to be performed, A storage unit stores the color measurement information measured by the image color measurement unit as historical data in association with the paper information, When a color measurement instruction is received, a control unit determines whether or not color measurement by the image color measurement unit is necessary based on the paper information of the paper to be measured and the history data, A colorimetric system equipped with the following features.

[0011] (2) When the control unit receives a color measurement instruction, it determines, based on the paper information of the paper to be measured, whether or not the color measurement information associated with the same paper information exists in the history data. If present, it is decided not to perform the color measurement. The colorimetric system described in (1) above, which determines to perform the colorimetric measurement if the color is not present.

[0012] (3) An image forming unit that forms an image on paper, The colorimetric system according to (1) above, wherein the image forming unit forms the plurality of patch images on the paper during color measurement.

[0013] (4) The colorimetric system according to (3) above, wherein the history data is associated with a profile used for output correction of the image forming unit, which is generated based on the colorimetric information.

[0014] (5) When the control unit determines that the color measurement information for the same paper information already exists in the history data and that the color measurement should not be performed, The colorimetric system according to (4) above, which reads the profile from the history data of the storage unit and uses it for image formation in the image forming unit.

[0015] (6) The color measurement system according to (1) above, wherein the paper information includes information on the paper type or paper physical properties.

[0016] (7) The color measurement system according to (6) above, wherein the paper physical properties include at least one of the stiffness, basis weight, paper thickness, moisture content, surface property, and paper resistance of the paper.

[0017] (8) The color measurement system according to (1) above, wherein the history data stores color measurement execution information associated therewith, and the color measurement execution information includes at least one of environmental information on the temperature and / or humidity at the time of color measurement, date and time information at the time of color measurement, and setting information indicating the color measurement conditions of the color measurement.

[0018] (9) When the control unit receives a color measurement instruction, it acquires the paper information of the paper to be color measured and environmental information indicating the current temperature and / or humidity, determines whether there is history data in the history data in which the paper information is the same and the difference between the current environmental information and the environmental information at the time of color measurement execution is within a predetermined range, if it exists, determines not to execute the color measurement, if it does not exist, determines to execute the color measurement. The color measurement system according to (8) above.

[0019] (10) Equipped with a timer, when the control unit receives a color measurement instruction, it acquires the paper information of the paper to be color measured and the current date and time information, determines whether there is history data in the history data in which the paper information is the same and the elapsed period from the date and time information at the time of color measurement execution is within a predetermined range, if it exists, determines not to execute the color measurement, if it does not exist, determines to execute the color measurement. The color measurement system according to (8) above.

[0020] (11) The image colorimetric unit is capable of performing a first colorimetric mode and a second colorimetric mode in which the number of patch images to be colored is smaller than that of the first colorimetric mode. In the first colorimetric mode, the colorimeter is moved in the width direction perpendicular to the paper transport direction, and the paper is moved in the transport direction, thereby reading multiple patch images on the paper arranged in the transport direction and the width direction to perform color measurement. In the second colorimeter mode, with the colorimeter fixed, the paper is moved in the transport direction, and multiple patch images on the paper arranged in the transport direction are read to perform color measurement. The control unit, in the color measurement instruction, When the first color measurement mode is specified, the system determines whether or not color measurement by the image color measurement unit is necessary based on the paper information of the paper to be measured. The colorimetric system described in (1) above, which, when color measurement in the second colorimetric mode is specified, executes the second colorimetric mode without making a determination of necessity.

[0021] (12) A color measurement method performed in a color measurement system comprising: an image color measurement unit that reads multiple patch images on paper arranged in the transport direction and the width direction by moving a colorimeter in a width direction perpendicular to the paper transport direction and moving the paper in the transport direction, and performs color measurement; and a storage unit that stores the color measurement information measured by the image color measurement unit as history data in association with the paper information of the paper, Step (a) of receiving color measurement instructions, (b) A step of obtaining paper information of the paper on which to measure color, A color measurement method comprising step (c) determining whether or not color measurement by the image color measurement unit is necessary based on the paper information obtained in step (b) and the history data.

[0022] (13) In step (c), based on the paper information of the paper to be measured, it is determined whether or not the color measurement information associated with the same paper information exists in the history data. If present, it is decided not to perform the color measurement. The color measurement method described in (12) above, wherein if the color does not exist, it is determined to perform the color measurement described above.

[0023] (14) A control program executed in a colorimetric system comprising: an image colorimetric unit that reads multiple patch images on sheets of paper arranged in the transport direction and the width direction by moving a colorimeter in a width direction perpendicular to the paper transport direction and moving the paper in the transport direction, and performs color measurement; and a storage unit that stores the color measurement information measured by the image colorimetric unit as history data in association with the paper information of the paper, Step (a) of receiving color measurement instructions, (b) A step of obtaining paper information of the paper on which to measure color, A control program for causing a computer to perform a process including step (c) determining whether or not color measurement by the image colorimeter is necessary based on the paper information obtained in step (b) and the history data.

[0024] (15) In step (c), based on the paper information of the paper to be measured, it is determined whether or not the color measurement information associated with the same paper information exists in the history data. If present, it is decided not to perform the color measurement. The control program described in (14) above, which determines to perform the color measurement if it does not exist. [Effects of the Invention]

[0025] The colorimeter system according to the present invention comprises: an image colorimeter unit that reads multiple patch images on paper arranged in the transport direction and the width direction by moving a colorimeter in the width direction perpendicular to the paper transport direction and moving the paper in the transport direction, and performs color measurement; a paper information acquisition unit that acquires paper information of the paper to be measured; a storage unit that stores the color measurement information measured by the image colorimeter unit as history data associated with the paper information; and a control unit that, when a color measurement instruction is received, determines whether or not color measurement by the image colorimeter unit is necessary based on the paper information of the paper to be measured and the history data. This makes it possible to appropriately determine whether or not color measurement by the colorimeter is necessary while suppressing resource consumption and system load. [Brief explanation of the drawing]

[0026] The advantages and features provided by one or more embodiments of the present invention will be better understood from the following detailed description and accompanying drawings. However, these are for illustrative purposes only and are not intended to limit the present invention. [Figure 1] This figure shows a schematic configuration of the colorimetric system according to this embodiment. [Figure 2] This is a block diagram of the colorimetric system. [Figure 3] This is a table used to explain the paper information associated with the paper tray. [Figure 4] This is a schematic perspective view showing the configuration of the image colorimeter. [Figure 5] This is a schematic diagram illustrating the first colorimetric mode. [Figure 6] This is a schematic diagram illustrating the second colorimetric mode. [Figure 7] This is a table showing historical data. [Figure 8] This is a table showing color measurement information. [Figure 9] This is a table showing color measurement execution information. [Figure 10A] This is a flowchart showing the colorimetric measurement method. [Figure 10B]This is a flowchart that follows the steps in Figure 10A. [Figure 11] This is an example of an operation screen for receiving various color measurement execution information. [Figure 12] This is an example of an operation screen for accepting requests to reuse matching historical data. [Figure 13] This is an example of an operation screen for accepting requests to determine whether or not to perform color measurement. [Modes for carrying out the invention]

[0027] Embodiments of the present invention will be described below with reference to the attached drawings. However, the scope of the present invention is not limited to the disclosed embodiments. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted. Also, the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios. In the drawings, the vertical direction is the Z direction, the colorimetric system or the front and back directions are the Y direction, and the direction perpendicular to these Y and Z directions is the X direction. The X direction is also called the paper transport direction. The Y direction is also called the width direction (or CD direction). In this embodiment, the paper includes printing paper (hereinafter simply referred to as paper) and various films. In particular, the paper includes those manufactured using plant-derived mechanical pulp and / or chemical pulp. The types of paper include coated paper such as gloss paper and matte paper, and uncoated paper such as plain paper and fine paper, etc.

[0028] In the following explanation, the electrophotographic method using toner will be used as an example of the image forming apparatus, but other methods such as the inkjet method may also be applied.

[0029] Figure 1 is a diagram showing the schematic configuration of the colorimetric system 1000 according to this embodiment. Figure 2 is a block diagram showing the hardware configuration of the colorimetric system 1000. As shown in Figure 1, the colorimetric system 1000 includes an image forming apparatus 100, a paper feeder 200, a paper physical property detection apparatus 300, a colorimetric apparatus 400, and a post-processing apparatus 500, which are mechanically and electrically connected to each other. The colorimetric system 1000 is also connected to a terminal device such as a PC.

[0030] (Image forming apparatus 100) The image forming apparatus 100 performs image formation on the paper 90 that has been sent from the upstream paper property detection apparatus 300.

[0031] (Paper feeder 200) The paper feeder 200 has multiple paper trays 131 to 133 and feeds one sheet of paper at a time from the top of the stack of paper contained in the paper trays 131 to 133, etc., according to the settings of the print job. The fed paper is then measured for its physical properties via the downstream paper property detection device 300, and further downstream, an image is formed on it by the image forming device 100. Multiple paper feeders 200 can be connected, and two or three paper feeders can be connected upstream.

[0032] (Paper physical properties detection device 300) The paper property detection device 300 has a paper property detection unit 17, which detects the paper properties of the transported paper. The paper property detection unit 17 includes a first detection unit 171 located in the transport path 142 and a second detection unit 172 located in the transport path 143 downstream of the first detection unit 171. Details of these will be described later.

[0033] (Color measurement device 400) The colorimeter 400 has an image colorimeter 18, and when executing a colorimeter mode (the first and second colorimeter modes described later), it measures the color of the patch image formed on the paper 90 transported on the branched transport path 147. Details regarding the image colorimeter 18 will be described later.

[0034] (Post-treatment device 500) The post-processing device 500 performs post-processing on or discharges the paper 90 sent from the image forming apparatus 100, according to the settings of the print job. The post-processing device 500 is equipped with a plurality of output trays T2 and T3. Output trays T2 and T3 are selected according to the settings of the print job. In addition, the color measurement mode is executed, and the patch image is formed and the color measured paper 90 is discharged to the output tray T2, for example, via the transport path 149. The post-processing device 19 performs at least one post-processing on the image-formed paper 90, such as stapling, punching, cutting, folding, and binding.

[0035] As shown in Figure 2, the colorimetric system 1000 includes a control unit 11, a storage unit 12, a paper feeding unit 13, a transport unit 14, an operation display unit 15, an image forming unit 16, a paper physical property detection unit 17, an image colorimetric unit 18, a post-processing unit 19, a communication unit 20, an environmental sensor 21, and a timer 22.

[0036] (Control Unit 11) The control unit 11 is composed of a CPU, ROM, RAM, etc. The control unit 11 executes various processes by running programs stored in the ROM and the memory unit 12, and controls each part of the device and performs various calculations according to the program. In the example shown in Figure 2, there is one control unit 11, and it is described as being located in the image forming apparatus 100, but the control unit 11 may be located in each of the devices 100 to 500. The same applies to the memory unit 12 and communication unit 20 described below, and they may be located in each of the devices 100 to 500.

[0037] (Storage unit 12) The storage unit 12 includes an auxiliary storage unit such as a hard disk for storing various programs and data. The storage unit 12 stores information about the paper stored in each paper tray. The storage unit 12 also stores a history data DB (database) containing multiple history data. Details of these will be described later. The storage unit 12 also stores the paper profile and the colorimetric chart (also called the output chart) for color measurement (see Figure 5, etc., described later).

[0038] (Paper feed section 13) Referring to Figures 1 and 2, the paper feeding unit 13 is equipped with multiple paper trays and feeds the paper 90 stored in the paper trays one sheet at a time, sending it to the transport path of the transport unit 14.

[0039] The transport unit 14 includes transport paths 141 to 149 arranged within each of the devices 100 to 500. The transport unit 14 is equipped with paper detection sensors, a plurality of transport rollers, and drive motors (none of which are shown) that drive these transport rollers, all located within these transport paths 141 to 149.

[0040] (Operation display section 15) The operation display unit 15 includes a touchscreen, a numeric keypad, a start button, a stop button, etc. The operation display unit 15 displays the status of the image forming apparatus 100 or the colorimetric system 1000 and is used to input instructions from the user, such as the type of paper placed in the paper tray and instructions for color measurement. In this embodiment, the paper property detection unit 17 and / or the operation display unit 15, into which paper information is input by the user, function as a paper information acquisition unit.

[0041] (Image forming unit 16) The image forming unit 16 is located within the image forming apparatus 100. The image forming unit 16 forms an image on the paper transported along the transport path 144, for example, by an electrophotographic method. The image forming unit 16 includes writing units corresponding to each of the basic colors Y (yellow), M (magenta), C (cyan), and K (black), a photosensitive drum, and a developer that contains a two-component developer consisting of toner and carrier for each color. The image forming unit 16 also includes an intermediate transfer belt, a secondary transfer unit, and a fixing unit. The toner images formed on the photosensitive drum by the developer of each color are superimposed on the intermediate transfer belt and transferred to the transported paper 90 in the secondary transfer unit. The toner image on the paper 90 is fixed to the paper 90 by heating and pressurizing in the downstream fixing unit. When performing double-sided printing, in which an image is formed on the back side of the paper 90, the paper 90 with an image formed on one side is transported to the transport path 145 for double-sided image formation located at the bottom of the apparatus body. The paper 90 transported along this transport path 145 is flipped over via a switchback path, then merges with the main transport path 144 for single-sided paper, where an image is formed on the other side of the paper 90 again in the image forming unit 16.

[0042] (Paper physical properties detection unit 17) The paper property detection unit 17 is located within the paper property detection device 300. The paper property detection unit 17 has multiple sensors and includes a first detection unit 171 located in the transport path 142 and a second detection unit 172 located in the transport path 143 downstream of the first detection unit 171. The transport path 143 is a transport path branched from the main transport path 142, and the paper 90 detected by the second detection unit 172 is discharged to the upper discharge tray T1 (hereinafter also referred to as the purge tray).

[0043] Multiple sensors 1 to 3 located in the first detection unit 171 each detect paper thickness, basis weight, moisture content, or their corresponding physical properties. These sensors located in the first detection unit 171 detect various paper properties while the transported paper 90 is being transported, without stopping it.

[0044] "Paper thickness" is obtained by sensor 1 detecting characteristics corresponding to the paper's thickness. Sensor 1 sandwiches the paper between two components, such as a pair of transport rollers, and measures the distance between these two components.

[0045] "Basis weight" is obtained by sensor 2 detecting characteristics corresponding to the basis weight of the paper. Sensor 2 consists of, for example, transmissive and reflective optical sensors. Basis weight is obtained by sensor 2 measuring the attenuation (transmittance) of light passing through the paper.

[0046] The "moisture content" is obtained by sensor 3 detecting characteristics corresponding to the moisture content (also called water content) of the paper. Sensor 3 optically detects the amount of light absorbed by the OH group using a near-infrared method based on the transmitted light from the paper.

[0047] Multiple sensors 4 to 6 located in the second detection unit 172 detect stiffness, surface properties, paper resistance (electrical resistance), or their corresponding physical properties, respectively. These sensors located in the second detection unit 172 temporarily stop the transported paper 90 at each detection position to detect various paper properties.

[0048] "Rigidity" is obtained by sensor 4 detecting characteristics corresponding to the rigidity of the paper. Sensor 4 measures the pressing force when the trailing edge of the free end of the paper is pressed. "Rigidity" constitutes a value related to the paper bending strength.

[0049] "Surface quality" is obtained by detecting characteristics corresponding to the smoothness of the paper's surface using sensor 5. "Surface quality" is also referred to as smoothness. Sensor 5 consists of an irradiating unit and a light receiving unit. For example, sensor 5 irradiates the surface of the paper with light at an incident angle of 75 degrees and optically detects the specularly reflected and diffusely reflected light from the paper surface using two sensors. "Surface quality" constitutes a value related to the surface condition of the paper.

[0050] "Paper resistance" is obtained by sensor 6 detecting characteristics corresponding to the electrical resistance inside or on the surface of the paper. Sensor 6 measures the voltage and current flowing when a high voltage is applied to the paper. "Paper resistance" constitutes a value related to the volume resistance of the paper.

[0051] The number of sensors in the paper property detection unit 17 is not limited to six; other sensors that detect paper properties may be included, or some sensors may be omitted. For example, it may have a line sensor that optically detects the size (shape) of the paper 90, with the entire width of the paper as its detection area.

[0052] (Paper type determination process) The paper 90 is transported from the target paper feed tray (e.g., paper feed tray 131), and the paper properties are measured by the paper property detection unit 17. The paper properties to be measured include those obtained by each of the sensors described above. For example, the control unit 11 performs paper type determination and basis weight classification determination based on the obtained paper properties, such as basis weight, paper thickness, and surface properties. Paper types include classifications such as plain paper, fine paper, and coated paper. These paper type determinations and basis weight classification determinations may be performed using a rule-based method, and a trained model (paper type discrimination engine) and a paper profile are used to determine the paper type and basis weight classification. Here, a "paper profile" is a pre-registered record of a particular paper, associating its measured values ​​from the paper property detection unit 17 with characteristic data, paper size, and an arbitrary identification name (e.g., paper brand) entered by the user. A paper brand is a further subdivision of paper types by specifying the brand of the paper manufacturer, and when a paper brand is specified, the paper type is also specified. The "paper type discrimination engine," also known as the trained model, is a trained model generated through supervised learning using training data, with the detection output from the paper property detection unit 17 of the paper 90 as the input value and the paper type information set by the user of the paper 90 as the correct label. After the paper type determination and basis weight classification determination are performed by the control unit 11, the determination results are displayed on the operation display unit 15. The user confirms the determination result (by pressing the confirmation button), and the determination result is confirmed and stored in the storage unit 12, linked to the paper tray and paper type information.

[0053] Figure 3 is a diagram illustrating the paper information associated with the paper feed tray. Table 1 in Figure 3 shows the paper information associated with the paper feed tray. Table 2 shows the contents of the paper information. The paper information includes data on paper properties 1 to 6 detected by the paper property detection unit 17. The paper type is determined from this paper property data by the paper type determination process described above, or is entered by the user through the operation display unit 15. This paper type setting and paper property detection are performed automatically by the paper property detection unit 17 each time new paper is loaded into the paper feed tray, or by instructions from the user via the operation display unit 15. The paper 90 used for detection is discharged into the output tray T1.

[0054] (Image colorimetric unit 18) The image colorimetric unit 18 is located within the colorimetric device 400. The colorimetric device 400 is equipped with a main transport path 146 and a U-shaped transport path 147 that branches off downward from it. When colorimetric measurement is not performed, for example, during normal image formation, the paper 90 is sent to the downstream post-processing device 500 via the transport path 146. On the other hand, when colorimetric measurement is performed, the paper 90 is transported to the branched transport path 147, and colorimetric measurement is performed by the image colorimetric unit 18 located on this transport path 147.

[0055] Figure 4 is a schematic perspective view showing the configuration of the image colorimeter 18. The image colorimeter 18 has a head 181 with a spectrophotometric colorimeter built in, and a moving mechanism 182 that moves the head 181 and the internal colorimeter 80 in the width direction. The colorimeter 80 built into the head 181 irradiates an image formed on paper with light from a specific light source, detects the spectral reflectance of the reflected light for each wavelength, and reads (measures) the color of the image formed on the paper. The colorimeter 80 outputs a Lab value as the result of the color measurement to the control unit 11. The Lab value is a numerical representation of color in the L*a*b* color space using a combination of (L*, a*, b*). In addition, D50 (light with a color temperature of 5000K), A light source (light with a color temperature of approximately 2856K), and A light source with a filter that removes the UV component from the A light source (UV filter) can be selected as light sources. The colorimetric diameter (spot diameter) used for color measurement is several millimeters, for example, 8 mm. The size of the patch image, described later, is set to a size that encompasses this diameter.

[0056] The moving mechanism 182 has two support parts 81a, 81b attached to the housing, a pair of guide rails 82a, 82b supported by these and extending along the Y direction (CD direction), and a slider 83 slidably mounted on the guide rails 82a, 82b. The head 181 is mounted on the slider 83 so as to be movable in the width direction. A colorimeter 80 is built into the head. The slider 83 is driven by a drive unit 84 consisting of a motor, pulley, belt, etc.

[0057] (First and second color measurement modes) Next, we will explain the color measurement performed by the image colorimeter 18, referring to Figures 5 and 6.

[0058] Figure 5 is a schematic diagram illustrating the first colorimetric mode. Figure 5(a) shows a sheet of paper 90 with an image formed using the output chart 1 used in the first colorimetric mode. The first colorimetric mode, also called the high-precision colorimetric mode, involves arranging multiple patch images (generally 100 or more) with different color combinations and color densities across the entire surface of the sheet of paper 90, and performing color management based on the colorimetric results. For example, a profile (also called an image forming profile) of the image forming apparatus 100 is generated (updated) based on the colorimetric results. This profile is, for example, a lookup table for determining the YMCK output signal for an input image signal based on print data, and is used for output correction of the image forming unit 16.

[0059] As an example of output chart 1, a colorimetric chart of the Japan Color standard can be used. The Japan Color standard colorimetric chart has a large number of colorimetric patches (1617 patches), enabling more accurate color management. However, the colorimetric chart formed in the colorimetric area is not limited to the Japan Color standard colorimetric chart; a chart with fewer patches may also be used. The size of each patch image is set to be slightly larger than the colorimetric diameter (spot diameter), as described above. Figure 5(a) shows an example where multiple patch images are placed on a single sheet of paper 90, but since the number of patches that can be placed on a single sheet of paper is limited, output chart 1 will be output across multiple sheets of paper 90 depending on the size of the cut paper.

[0060] Figure 5(b) shows the color measurement order of the patch images in the first color measurement mode. In this figure, the patch images are shown with dashed lines for visibility. In the first color measurement mode, the patch images are arranged across the entire surface of the paper 90 in the output chart 1. Therefore, during color measurement, the head 181 of the image color measurement unit 18 is moved back and forth in the width direction by the moving mechanism 182, and the color of each patch image is measured. Specifically, when the image patch in the front row of the paper 90 reaches directly below the head 181 on the transport path 147, the paper 90 pauses. Then, the head 181 is moved sequentially from one end in the width direction to the other end of the multiple image patches in the front row, and the built-in colorimeter 80 measures the color of each of the multiple image patches. Next, the paper 90 is moved slightly until the patch image of the next row is directly below the head 181. Then, the head 181 is moved sequentially from one end in the width direction to the other, in the opposite direction from the front row, and the color of each of the multiple image patches is measured. These operations are repeated to measure the color of all the image patches on the entire surface of the paper 90. If multiple sheets of paper 90 are to be used, this process is repeated.

[0061] Figure 6 is a schematic diagram illustrating the second color measurement mode. Figure 6(a) shows a sheet of paper 90 with an image formed using the output chart 2 used in the second color measurement mode. The second color measurement mode is also called the simplified color measurement mode, and it measures fewer patch images than the first color measurement mode. In the second color measurement mode, multiple patch images (approximately a dozen or so) with different color combinations and color densities are arranged vertically (in the transport direction) across a portion of the sheet of paper 90 so that the head 181 does not need to move, and color management is performed based on the color measurement results. For example, based on the color measurement results, it is checked whether the color output of the image forming apparatus 100 is correct (inspection). If there is a problem, such as when the color is outside the specified range, an error is notified, or a notification is issued prompting the execution of the first color measurement mode.

[0062] Figure 6(b) shows the color measurement order of the patch images in the first color measurement mode. In this figure, the patch images are shown with dashed lines for visibility. In the second color measurement mode, the patch images are arranged vertically on a portion of the paper 90 in the output chart 2. Therefore, the head 181 of the image color measurement unit 18 is fixed during color measurement. The colorimeter 80 measures the colors of multiple vertically arranged image patches while moving or pausing the paper 90.

[0063] (Post-processing 19) As described above, the post-processing unit 19 is located within the post-processing unit 500. The post-processing unit 19 performs at least one post-processing operation on the image-formed paper 90, including stapling, punching, cutting, folding, and binding.

[0064] (Communications Section 20) The communication unit 20 is an interface for communicating with other devices.

[0065] (Environmental sensor 21) The environmental sensor 21 measures the environment surrounding the colorimetric system 1000. The environmental sensor 21 includes a temperature sensor and a humidity sensor located inside the housing of the colorimetric system 1000, which measure temperature and humidity.

[0066] (Timer 22) Timer 22 is an RTC (Real-Time Clock) and has the function of outputting the current date and time, as well as a timekeeping function. Time drift may be corrected by using NTP (Network Time Protocol).

[0067] (Historical data) Next, the history data stored in the history data DB of the storage unit 12 will be described. Table 3 in Figure 7 is an example of history data. The history data includes the measurement ID, the device ID of the colorimetric system 1000, paper information, colorimetric information, colorimetric execution information, profile, and the ID of the operator who issued the colorimetric execution instruction. The colorimetric ID is the primary key and is automatically assigned each time a colorimetric measurement is performed in either the first or second colorimetric mode. One history data is created for each colorimetric ID.

[0068] The contents of the paper information are as shown in Table 2 of Figure 3. This is the paper information of the paper 90 on which color measurement was performed, and it is read from the storage unit 12 and linked to the history data.

[0069] The color measurement information is the color measurement result, and Table 41 shown in Figure 8 shows the color measurement result for each patch image measured in the first color measurement mode with measurement ID 001. Measurement results corresponding to 128 patch images are recorded. Table 42 shown in Figure 8 shows the color measurement result for each of the 12 patch images measured in the second color measurement mode with measurement ID 002.

[0070] Note that the numbers 128 and 12 for patch images in Tables 41 and 42 are merely examples. Table 41 may record colorimetric values ​​for more than 1,000 patch images, while Table 42 may record a smaller number, for example, just a few patch images.

[0071] The colorimetric execution information shown in Table 5 of Figure 9 is supplementary information (metadata) related to the execution of colorimetric measurement. The colorimetric execution information includes at least one of the following: environmental information, date and time information, and setting information. The environmental information is data detected by the environmental sensor 21 at the time of colorimetric execution. The date and time information is data output by the timer 22 at the time of colorimetric execution. The setting information is data set by the user at the time of colorimetric execution using the operation display unit 15, etc. The setting information includes the light source type of the colorimeter 80 and patch image conditions 1 and 2. As mentioned above, there are three types of light sources: D50, A light source, and A light source with a UV filter.

[0072] Patch image condition 1 is the screen type setting when outputting by the image forming unit 16, and there are two types of screens: one that represents intermediate density colors with dots and another that represents them with lines. Patch image condition 2 is the intensity setting of UCR (Under Color Removal) / GCR (Gray Component Replacement), which replaces the YMC color signal with the K color signal. The stronger the intensity, the more cost reduction can be achieved by replacing YMC toner with K toner.

[0073] (Color measurement method) Next, the colorimetric method performed in this embodiment will be described with reference to Figures 10A and 10B. Figure 10A is a flowchart of the colorimetric method. Figure 10B is a flowchart that follows Figure 10A.

[0074] (Step S31) Here, the control unit 11 receives input of color measurement execution information from the user through the operation display unit 15. Figure 11 shows examples of various operation screens displayed on the operation display unit 15 used in the process of S31.

[0075] As shown in operation screen d1 of Figure 11, the first step is to accept the selection of the paper tray. Next, the selection of high-precision / simple colorimetric mode (first and second colorimetric modes) is accepted via operation screen d2. In the figure, the high-precision colorimetric mode is selected. Then, via operation screen d3, the light source type of the setting information is accepted as colorimetric execution information. Subsequently, the patch image conditions 1 and 2 are accepted via operation screens d4 and d5, respectively. In addition, text input for memos may also be accepted.

[0076] (Step S32) Next, the control unit 11 obtains the paper information (hereinafter referred to as "paper information a") associated with the paper tray selected in step S31 from the storage unit 12 (see Figure 3).

[0077] (Step S33) Next, the control unit 11 acquires current environmental information and date / time information from the environmental sensor 21 and timer 22 (hereinafter referred to as environmental information b and date / time information c).

[0078] (Step S34) The control unit 11 searches the history data DB in the storage unit 12 using the paper information a and determines whether there is any history data with matching paper information. Matching paper information means that the paper type and basis weight classification are the same. The basis weight classification is determined by the judgment value of the basis weight sensor 2. It also means that all of the physical property values ​​(physical properties 1 to 6) of the paper properties fall within a tolerance of error of 20%. That is, it searches the paper information of the history data d and determines whether all of the physical property values ​​fall within a range of plus or minus 20% from each of the values ​​of the multiple physical property values ​​of paper information a.

[0079] (Step S35) The history data database is searched, and if history data matching the paper information (hereinafter referred to as history data d, or past history information) exists (YES), the process proceeds to step S36; otherwise, the process proceeds to step S44 (indicated by the circled number 20).

[0080] (Step S36) If the colorimetric mode selected in step S31 is the high-precision colorimetric mode (first colorimetric mode) (YES), the control unit 11 proceeds to step S37; if it is the simplified colorimetric mode (second colorimetric mode) (NO), it proceeds to step S44 (indicated by the circled number 20).

[0081] (Step S37) The control unit 11 determines whether the setting information of the history data d matches the setting information indicating the color measurement conditions entered in step S31. Specifically, it determines whether the selected light source, screen type, and UCR / GCR settings in the setting information of the history data d match the setting information entered in step S31. If all are the same (YES), the process proceeds to step S38; if any of them are not the same (NO), the process proceeds to step S44 (indicated by the circled number 20).

[0082] (Step S38) The control unit 11 compares the environmental information in the historical data d with the current environmental information b. If the difference is within a predetermined value (for example, within plus or minus 20%), the process proceeds to step S39. On the other hand, if either is not the same, the process proceeds to step S44 (indicated by the circled number 20).

[0083] (Step S39) The control unit 11 compares the date and time information of the history data d with the current date and time information c. If the elapsed time from the date and time information of the history data d is within a predetermined value (for example, within one week) (YES), the process proceeds to step S41 (indicated by the circled number 10). On the other hand, if either is not the same (NO), the process proceeds to step S44 (indicated by the circled number 20).

[0084] (Step S41) In step S41 of Figure 10B, various information from the history data d is displayed. The operation screen d5 shown in Figure 12 is an example of the display of various information. The various information displays the color measurement mode, date and time of execution, operator, environmental information, paper information, etc., that were performed in the history data d (past history information). In addition, setting information and paper physical property values ​​may also be displayed using scrolling display or the like.

[0085] (Step S42) Here, the control unit 11 accepts a choice from the user to either perform color measurement or use historical data. If the "Execute" button is pressed on the operation screen d5 in Figure 12 (execution), the process proceeds to step S44. On the other hand, if the "Cancel" button is pressed on the operation screen d5 (cancellation), the process proceeds to step S43.

[0086] (Step S43) Here, the control unit 11 acquires (reuses) the profile associated with the history data d. Alternatively, the control unit 11 may acquire past color measurement results associated with the history data d and create a new profile based on these results.

[0087] (Step S44) Here, the control unit 11 accepts the user's selection again whether or not to perform color measurement. If the OK button is pressed on the operation screen d6 in Figure 13 (YES), the process proceeds to step S45. If the Cancel button is pressed (NO), the process is stopped without performing color measurement (end). (Step S45) The colorimeter system 1000 transports the paper 90 from the paper tray set in step S31 and performs color measurement in the colorimeter mode set in step S31.

[0088] (Step S46) The control unit 11 creates a profile based on the color measurement results obtained in step S45. Note that profile creation is performed only when the color measurement mode performed in step S45 is the high-precision color measurement mode; no profile is created in the simplified color measurement mode.

[0089] (Step S47) The control unit 11 assigns a new color measurement ID to the history data DB, associates it with a series of information including paper information, color measurement execution information, color measurement information, and profile, and registers it as history data in the history data DB of the storage unit 12, thereby ending the color measurement process (end). From this point onward, image formation is performed using the newly created profile (or a reused profile).

[0090] Thus, the colorimetric system according to this embodiment includes an image colorimetric unit that reads multiple patch images on paper arranged in the transport direction and the width direction by moving a colorimeter in the width direction perpendicular to the paper transport direction and moving the paper in the transport direction, thereby performing color measurement. The colorimetric system also includes a paper information acquisition unit that acquires paper information of the paper on which color measurement is performed, The system includes a storage unit that stores the color measurement information measured by the image color measurement unit as history data associated with the paper information, and a control unit that, upon receiving a color measurement instruction, determines whether or not color measurement by the image color measurement unit is necessary based on the paper information of the paper to be measured and the history data. This allows for an appropriate determination of whether or not color measurement by the color measurement unit is necessary while minimizing resource consumption and system load.

[0091] The configurations of the colorimeter 400 and the colorimeter system 1000 equipped therewith described above are described as the main configurations in order to explain the features of the above embodiment, and are not limited to the above configurations, and can be modified in various ways within the scope of the claims. Furthermore, they do not exclude the configurations that are generally found in image forming apparatuses.

[0092] Furthermore, the means and methods for performing various processing in the colorimetric system 1000 according to the above embodiment can be implemented by either a dedicated hardware circuit or a programmed computer. The program may be provided, for example, on a computer-readable recording medium such as a USB memory stick or a DVD (Digital Versatile Disc)-ROM, or it may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable recording medium is usually transferred to and stored in a storage unit such as a hard disk. The program may also be provided as a standalone application software, or it may be incorporated into the software of the device as a function of the device.

[0093] While embodiments of the present invention have been described and illustrated in detail, the disclosed embodiments are for illustrative purposes only and are not limiting. The scope of the present invention should be interpreted in accordance with the language of the appended claims. [Explanation of symbols]

[0094] 1000 colorimetric systems 100 Image forming apparatus 200 Paper feeder 300 Image forming apparatus 400 Colorimetric device 500 Post-processing equipment 11 Control Unit 12 Storage section 13 Paper feed section 14 Conveying section 15 Operation display section 16 Image forming unit 17 Paper physical property detection unit 18 Image colorimeter 181 head 80 Colorimeter 182 Moving mechanism 19 Post-processing 20 Communications Department 21 Environmental Sensors 22 Timer

Claims

1. An image colorimeter unit moves a colorimeter in the width direction perpendicular to the paper transport direction, and moves the paper in the transport direction, thereby reading multiple patch images on the paper arranged in the transport direction and the width direction and performing color measurement. A paper information acquisition unit that acquires paper information of the paper on which color measurement is to be performed, A storage unit stores the color measurement information measured by the image color measurement unit as historical data in association with the paper information, When a color measurement instruction is received, a control unit determines whether or not color measurement by the image color measurement unit is necessary based on the paper information of the paper to be measured and the history data, A colorimetric system equipped with the following features.

2. When the control unit receives a color measurement instruction, it determines, based on the paper information of the paper to be measured, whether or not the color measurement information associated with the same paper information exists in the history data. If present, it is decided not to perform the color measurement. The colorimetric system according to claim 1, wherein if the color is not present, it is determined to perform the color measurement.

3. It includes an image forming unit that forms an image on paper, The colorimetric system according to claim 1, wherein the image forming unit forms the plurality of patch images on the paper during color measurement.

4. The colorimetric system according to claim 3, wherein the historical data is associated with a profile used for output correction of the image forming unit, which is generated based on the colorimetric information.

5. If the control unit determines that the color measurement information for the same paper information already exists in the history data and that the color measurement should not be performed, The colorimetric system according to claim 4, wherein the profile is read from the history data of the storage unit and used for image formation in the image forming unit.

6. The colorimetric system according to claim 1, wherein the paper information includes information on the type of paper or the physical properties of the paper.

7. The colorimeter according to claim 6, wherein the paper properties include at least one of the paper's stiffness, basis weight, thickness, moisture content, surface properties, and paper resistance.

8. The aforementioned history data is stored with associated color measurement execution information. The colorimetric system according to claim 1, wherein the colorimetric execution information includes at least one of environmental information such as temperature and / or humidity at the time the colorimetric was performed, date and time information at the time the colorimetric was performed, and setting information indicating the colorimetric conditions for the colorimetric.

9. When the control unit receives a color measurement instruction, The paper information of the paper to be measured and environmental information indicating the current temperature and / or humidity are obtained. In the aforementioned history data, it is determined whether there is any history data in which the paper information is the same and the difference between the current environmental information and the environmental information at the time of color measurement is within a predetermined range. If present, it is decided not to perform the color measurement. The colorimetric system according to claim 8, wherein if the color is not present, it is determined to perform the color measurement.

10. Equipped with a timer, When the control unit receives a color measurement instruction, The paper information of the paper to be measured and the current date and time information are obtained. In the aforementioned history data, it is determined whether there is any history data where the paper information is the same and the elapsed time from the date and time information at the time of color measurement is within a predetermined period. If present, it is decided not to perform the color measurement. The colorimetric system according to claim 8, wherein if the color is not present, it is determined to perform the color measurement.

11. The image colorimetric unit is capable of performing a first colorimetric mode and a second colorimetric mode in which the number of patch images to be colored is smaller than that of the first colorimetric mode. In the first colorimetric mode, the colorimeter is moved in the width direction perpendicular to the paper transport direction, and the paper is moved in the transport direction, thereby reading multiple patch images on the paper arranged in the transport direction and the width direction to perform color measurement. In the second colorimeter mode, with the colorimeter fixed, the paper is moved in the transport direction, and multiple patch images on the paper arranged in the transport direction are read to perform color measurement. The control unit, in the color measurement instruction, When the first color measurement mode is specified, the system determines whether or not color measurement by the image color measurement unit is necessary based on the paper information of the paper to be measured. The colorimetric system according to claim 1, wherein when color measurement in the second colorimetric mode is specified, the second colorimetric mode is executed without making a determination of necessity.

12. A color measurement method performed in a color measurement system comprising: an image color measurement unit that reads multiple patch images on paper arranged in the transport direction and the width direction by moving a colorimeter in a width direction perpendicular to the paper transport direction and moving the paper in the transport direction, and performs color measurement; and a storage unit that stores the color measurement information measured by the image color measurement unit as history data in association with the paper information of the paper, Step (a) of receiving color measurement instructions, (b) A step of obtaining paper information of the paper on which to measure color, A color measurement method comprising step (c) determining whether or not color measurement by the image color measurement unit is necessary based on the paper information obtained in step (b) and the history data.

13. In step (c), based on the paper information of the paper to be measured, it is determined whether or not the color measurement information associated with the same paper information exists in the history data. If present, it is decided not to perform the color measurement. The colorimetric method according to claim 12, wherein if the color is not present, it is determined to perform the color measurement.

14. A control program executed in a colorimetric system comprising: an image colorimetric unit that reads multiple patch images on paper arranged in the transport direction and the width direction by moving a colorimeter in the width direction perpendicular to the paper transport direction and moving the paper in the transport direction, and performs color measurement; and a storage unit that stores the color measurement information measured by the image colorimetric unit as history data in association with the paper information of the paper, Step (a) of receiving color measurement instructions, (b) A step of obtaining paper information of the paper on which to measure color, A control program for causing a computer to perform a process including step (c) determining whether or not color measurement by the image colorimeter is necessary based on the paper information obtained in step (b) and the history data.

15. In step (c), based on the paper information of the paper to be measured, it is determined whether or not the color measurement information associated with the same paper information exists in the history data. If present, it is decided not to perform the color measurement. The control program according to claim 14, which determines to perform the color measurement if the color does not exist.

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