Image forming device

Abstract

To strictly perform color number management in composing a gradation patch with respective pages.SOLUTION: An image forming apparatus determines the color of a gradation patch for gradation correction to be composed with an image of every page according to a color component used in the image, and composes the gradation patch in the determined color with the image. The image forming apparatus performs gradation correction for the image based on gradation correction information to perform image formation, measures the color of the gradation patch formed on a medium, and updates the gradation correction information based on a value of the measured color. The image forming apparatus executes gradation correction by using the gradation correction information during image formation.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus, and more particularly to a process for suppressing tone fluctuation during printing. [Background technology]

[0002] In order to suppress image quality fluctuations when printing a large number of pages, image forming devices can print gradation patches in the print margins of output paper, measure them with a colorimetric sensor installed downstream of the image forming unit, and feed back the correction values ​​to the image generating unit. Hereinafter, this process will be called real-time gradation correction.

[0003] Conventionally, various means for adjusting the color of a device have been proposed. For example, in Patent Document 1, the color of a device is adjusted before printing a job. In order to adjust the color of a device, a large number of patches may be printed, so that a color chart is printed across multiple sheets. In addition, when it is found that color adjustment is necessary as a result of comparing a read patch with a target color, the color adjustment is performed, and the color chart is printed again and compared with the target color. In Patent Document 1, in a case where a color chart is printed across multiple sheets and color measurement is performed, a means is provided for quickly detecting that color adjustment is necessary due to a difference in color from the target color. Specifically, in advance verification, the difference between each color patch and the target color is checked, and the color patches are laid out so that the color patches with the largest difference are printed first. Then, while printing a color chart, if color adjustment is necessary due to a difference in color from the target color while reading the printed color patch, the printing of the color chart is stopped and the color adjustment is performed. In this way, unnecessary color chart printing is eliminated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6422923 specification Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, there are two types of print data: full-color printing, which uses all toners (e.g., cyan, magenta, yellow, and black) that are available in the image forming device, and limited-color printing, which forms an image on a sheet of paper using a limited number of toners. In addition, print data may contain a mixture of full-color image pages and pages with a limited number of colors. Even if the printing system manages the number of colors for each page, all patches for real-time tone correction are printed on every page. In this case, color patches other than black toner are printed on black-and-white pages, which causes the black-and-white pages to be determined to be color pages, making it impossible to manage the number of colors for each page.

[0006] Therefore, the present invention aims to provide an image forming apparatus and a control method thereof that enable strict color number management for each page by switching the type of gradation patch printed for each color type used on the page to be printed. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention has the following configuration: That is, according to one aspect of the present invention, a determination unit determines a color of a gradation patch for gradation correction to be combined with an image in accordance with a color component used in the image; a synthesizing means for synthesizing the image with the gradation patch of the determined color to generate an image with the patch; a correction means for performing gradation correction on the patched image based on the gradation correction information for each color component to generate a corrected image; an image forming means for forming the corrected image on a medium; and updating means for measuring the color of the gradation patch formed on the medium and updating the gradation correction information based on the measured color value. death, An area in the image into which the gradation patch is to be synthesized is determined in advance; When the number of colors determined by the determining means is less than the number of the regions, if a setting is made to synthesize the gradation patch in the remaining region, the gradation patch of the color determined by the determining means is synthesized in the remaining region. The present invention provides an image forming apparatus comprising: Effect of the Invention

[0008] According to the present invention, by switching the type of tone patch to be printed for each color type used on a page to be printed, it is possible to perform strict color number management for each page. [Brief description of the drawings]

[0009] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. [Figure 1] A diagram explaining the configuration of a printing system. [Figure 2A] FIG. 1 is a block diagram illustrating a hardware configuration of an image processing apparatus. [Figure 2B] FIG. 1 is a block diagram illustrating a hardware configuration of an image forming apparatus. [Figure 3A] Block diagram for explaining the software configuration of the image processing device [Figure 3B] A block diagram illustrating a software configuration of an image forming apparatus. [Figure 4A-1] Printing process sequence diagram [Figure 4A-2] Printing process sequence diagram [Figure 4B] Printing process sequence diagram [Diagram 5] Reference value / correction value registration / deletion process sequence [Figure 6A] Reference value / correction value registration / deletion process flowchart [Figure 6B] Reference value / correction value registration / deletion process flowchart [Figure 7] Paper change screen transition diagram [Figure 8A] Patch positions for real-time tone correction and sensor reading positions [Figure 8B] Print document feed direction, print surface and sensor position [Figure 8C] Sample of reference value, measurement value, and correction value for tone correction (10 levels) [Figure 8D]Reference value management table and correction value management table for gradation correction [Figure 8E] Sample of reference value, measurement value, and correction value for gradation correction (20 steps) [Figure 8F] Samples of reference values, measurement values, and correction values ​​for tone correction (30 levels) [Figure 8G] Sample of reference value, measurement value, and correction value for gradation correction (40 steps) [Figure 9] Example of a screen for specifying color-related job properties [Figure 10] Tables that store jobs and job attribute tables [Figure 11] Toner color information and patch color layout for each page of each job [Figure 12] Flowchart for determining patch layout [Figure 13] Example of UI constraints table and warning screen [Figure 14] A flowchart for specifying only the colors specified in the specified color printing as adjustment patches and issuing a print instruction DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <<First embodiment>> Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0011] Hardware configuration Fig. 1 is a diagram for explaining the configuration of a printing system according to an embodiment of the present invention. As shown in Fig. 1, the printing system includes an information processing device 102, an image processing device 101, and an image forming device 103, which are connected via a LAN 100 (network). The image processing device 101 and the image forming device 103 are capable of printing a print job received from the information processing device 102. The information processing device 102 is also capable of generating a print job.

[0012] FIG. 2A is a block diagram for explaining a hardware configuration of an image processing apparatus 101 according to this embodiment. The image processing apparatus 101 has a function of forming an image to be printed on a sheet. A control unit 2200 including a central processing unit (CPU) 2101 controls the operation of the entire image processing apparatus 101. The CPU 2201 loads a program stored in a read only memory (ROM) 2202 or a storage 2204 into a RAM 2203, and executes the program to perform various controls such as print control. The ROM 2202 stores a control program executable by the CPU 2201, a boot program, and the like. The random access memory (RAM) 2203 is the main memory of the CPU 2201, and is used as a work area or a temporary storage area for loading various control programs. The storage 2204 stores print data, image data, various programs, and various setting information. In this embodiment, an auxiliary storage device such as a hard disk drive (HDD) is assumed as the storage 2204, but a non-volatile memory such as a solid state drive (SSD) may also be used. In the image processing device 101 according to the embodiment, one CPU 2201 executes each process shown in the flowcharts described later using one memory (RAM 2203), but other configurations are also possible. For example, each process shown in the flowcharts described later may be executed by making a plurality of CPUs, RAMs, ROMs, and storages work together. Also, some of the processes may be executed using hardware circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

[0013] An operation unit interface (I / F) 2205 connects an operation unit 2206 and the control unit 2200. The operation unit 2206 is provided with a display unit having a touch panel function, various hard keys, and the like, and functions as a display unit that displays information and a reception unit that receives instructions from a user.

[0014] The image processing unit 2207 has a function of a RIP (Raster Image Processor) that develops a print job received via a communication unit I / F 2208 and generates image data to be used for printing. The image processing unit 2207 can also convert the resolution of image data obtained by developing the print job and perform correction processing. In this embodiment, it is assumed that the image processing unit 2207 is realized by a hardware circuit (such as an ASIC or an FPGA), but this is not limited to this. For example, the image processing device 101 may further include a processor for image processing, and the processor may execute an image processing program to realize image processing and development processing into print data. In this case, the processor and the CPU 2201 cooperate to realize a flowchart described later. Furthermore, it is also possible to configure the CPU 2201 to execute a program for performing image processing, and to perform image processing and development processing of print data. Image processing may also be performed by any combination of these.

[0015] The control unit 2200 is connected to the LAN 100 via a communication unit I / F 2208. The communication unit I / F 2208 receives a print request (print job) from the information processing device 102 on the LAN 100. It also transmits a print image generated by the image processing device 101 together with a print control command to the image forming device 103 via the LAN 100 and receives the print result.

[0016] In this embodiment, the above-mentioned configuration example will be described as an example of a printing system, but the present invention is not limited to this, and it is sufficient that at least one information processing device and a printing device are connected to be able to communicate with each other via a network. The network may be wireless or wired.

[0017] FIG. 2B is a block diagram for explaining a hardware configuration of the image forming apparatus 103 according to the present embodiment. The image forming apparatus 103 has a function of forming an image to be printed on a sheet. In this embodiment, an image forming apparatus is explained as an example, but the image forming apparatus may be an image forming apparatus such as an MFP (Multi Function Peripheral) including a scanner or FAX function. A control unit 2100 including a CPU (Central Processing Unit) 2101 controls the operation of the entire image forming apparatus 103. The CPU 2101 loads a program stored in a ROM (Read Only Memory) 2102 or a storage 2104 into a RAM 2103, and executes the program to perform various controls such as print control and read control. The ROM 2102 stores a control program executable by the CPU 2101, a boot program, and the like. The RAM (Random Access Memory) 2103 is the main storage memory of the CPU 2101, and is used as a work area or a temporary storage area for loading various control programs. The storage 2104 stores print data, image data, various programs, and various setting information. In this embodiment, an auxiliary storage device such as a hard disk drive (HDD) is assumed as the storage 2104, but a non-volatile memory such as a solid state drive (SSD) may also be used. In the image forming apparatus 103 according to the embodiment, one CPU 2101 executes each process shown in the flowcharts described later using one memory (RAM 2103), but other configurations may be used. For example, each process shown in the flowcharts described later may be executed by cooperating with a plurality of CPUs, RAMs, ROMs, and storages. Also, some of the processes may be executed using hardware circuits such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0018] An operation unit interface (I / F) 2105 connects an operation unit 2106 and the control unit 2100. The operation unit 2106 is provided with a display unit having a touch panel function, various hard keys, and the like, and functions as a display unit that displays information and a reception unit that receives instructions from a user.

[0019] The image processing unit 2107 has a function of a RIP (Raster Image Processor) that develops a print job received via the communication unit I / F 2108 and generates image data to be used for printing. The image processing unit 2107 can also convert the resolution of image data obtained by developing the print job and perform correction processing. In this embodiment, it is assumed that the image processing unit 2107 is realized by a hardware circuit (such as an ASIC or an FPGA), but this is not limited to this. For example, the image forming apparatus 103 may further include a processor for image processing, and the processor may execute an image processing program to realize image processing and development processing into print data. In this case, the processor and the CPU 2101 cooperate to realize a flowchart described later. Furthermore, it is also possible to configure the CPU 2101 to execute a program for performing image processing, and to perform image processing and development processing of print data. Image processing may also be performed by any combination of these.

[0020] A printing unit (printer engine) 2109 prints an image on a sheet fed from a paper feed cassette (not shown) based on image data generated by the image processing unit 2107. The printing method of the printing unit 2109 may be an electrophotographic method or an inkjet method. Other printing methods such as a thermal transfer method may also be applied.

[0021] The colorimetric unit 2110 is located downstream of the paper transport path of the printing unit 2109, and measures the colors of the gradation patches of each color of the gradation correction mark formed on the printed paper using a color sensor such as a CIS, and obtains colorimetric data.

[0022] The control unit 2100 is connected to the LAN 100 via a communication unit I / F 2108. The communication unit I / F 2108 receives a print request (print job) from an information processing apparatus on the LAN 100.

[0023] In this embodiment, the above-mentioned configuration example will be described as an example of a printing system, but the present invention is not limited to this, and it is sufficient that at least one information processing device and a printing device are connected to be able to communicate with each other via a network. The network may be wireless or wired.

[0024] ● Software configuration FIG. 3A is a block diagram illustrating the software configuration of the image processing device 101 according to this embodiment.

[0025] When a job is input, the print job generation unit 301 generates a print job and registers it in the job control unit 303. The job control unit 303 notifies the page control unit 304 of the start of processing for all pages included in the registered print job, starting from the first page, to start page processing. When the page control unit 304 notifies the page control unit 304 that processing can start for the next page, the process of notifying the start of processing for the next page is repeated. Then, when the page control unit 304 notifies the print job generation unit 301 that processing has ended for all pages, the job control unit 303 notifies the print job generation unit 301 that the job has ended.

[0026] The page control unit 304 controls the processing of each page upon receiving a notification of the start of page processing from the job control unit 303. In addition, when the image forming apparatus 103 determines the patch type and performs patch composition processing, the page control unit 304 transmits a notification to that effect to the image forming apparatus 103.

[0027] The data reception control unit 302 receives the PDL data transmitted from the information processing device 102 via the communication unit I / F 2208 .

[0028] The PDL analysis unit 305 analyzes the received PDL data and converts it into intermediate data, and the RIP control unit 306 rasterizes the intermediate data and converts it into image data in a bitmap format. The generated bitmap format image data is sent to a patch type determination unit 310, which determines the type of patch to be combined with the print image, i.e., the type of gradation pattern for gradation correction. The type of gradation pattern may be determined for each color of coloring material (which will be called color component or primary color). In addition to the color, the gradation difference between single-color patches that make up the gradation pattern may be changed for each type of gradation pattern. That is, in this example, the type of gradation pattern may be classified by color and the gradation difference between the patches. Note that the gradation pattern may also be called a gradation patch.

[0029] The image generation unit 307 generates a print image from the generated image data in bitmap format. The image generation unit 307 also instructs the patch synthesis unit 309 to synthesize patches based on instructions from the page control unit 304. The image generation unit 307 controls the image processing unit 2207 in FIG. 2A. The patch synthesis unit 309 transmits an image in which gradation patches have been synthesized (also called an image with patches) to a print control data transmission / reception unit 311. The print control data transmission / reception unit 311 transmits the patch-synthesized data and adjustment instructions for the image forming apparatus 103 via a transmission unit I / F 2208. The UI control unit 308 provides a user interface to the operation unit 2206.

[0030] FIG. 3B is a block diagram illustrating the software configuration of the image forming apparatus 103 according to this embodiment.

[0031] The data reception control unit 322 receives data transmitted from the image processing device 101 via the communication unit I / F 2108. The page control unit 324 is included in the job control unit 323, and upon receiving a notification of the start of page processing from the patch synthesis unit 308 of the image processing device 101, instructs the patch type determination unit 337 to perform processing to determine patches to be synthesized into the image.

[0032] A patch type determination unit 337 determines the patch type to be combined with the image based on the toner color used in the print image. This is the same as in the information processing device 101.

[0033] The image generation unit 327 generates a print image from the generated bitmap image data. The image generation unit 327 also transfers the print image to a patch synthesis unit 329. The image generation unit 327 also generates a corrected print image (i.e., a corrected image) by reflecting correction information for the paper used for printing on the generated bitmap image data. The paper used for printing may also be called a sheet, a print medium, a recording medium, or simply a medium.

[0034] The engine control unit 328 includes a patch synthesis unit 329 , a correction information storage unit 330 , a reference information storage unit 331 , a color measurement sensor control unit 332 , a paper feed stage management unit 333 , a paper feed control unit 334 , and a print control unit 335 .

[0035] The patch synthesis unit 329 synthesizes the print image with gradation correction mark information (gradation patch) so that a gradation correction mark is formed in addition to the image formed based on the corrected print image received from the image generation unit 327.

[0036] The paper feed control unit 334 controls the paper feed tray according to the instructions of the print job, and transports and supplies the paper stored in the paper feed tray.

[0037] The print control unit 335 prints the print image with the gradation patch composited on the paper supplied by the paper feed control unit 334, and ejects the paper. In this embodiment, an image is formed on the paper based on image data to which gradation correction mark information (gradation patch) is added as necessary.

[0038] The color measurement sensor control unit 332 controls the color measurement unit 2110 to measure the tone correction marks formed on the paper, and obtains color measurement data.

[0039] The reference information storage unit 331 holds reference information generated based on color measurement data acquired by the color measurement sensor control unit 332 for each paper type set in a paper feed tray.

[0040] The correction information storage unit 330 stores correction information (also called gradation correction information) obtained by comparing the reference information stored in the reference information storage unit 331 with the colorimetric data acquired by the colorimetric sensor control unit 332, for each paper type set in the paper feed tray.

[0041] The paper feed tray management unit 333 manages information on the size and type of paper set in all paper feed trays provided in the image forming apparatus 103. Also, in response to a paper registration request from the UI control unit 336, the paper feed tray management unit 333 clears the reference information for the paper type to be removed for replacement that is stored in the reference information storage unit 331. Furthermore, if the correction information storage unit 330 stores correction information for the paper type to be removed for replacement, the correction information is also cleared.

[0042] When a user operates the operation unit 2106 to set paper information for a paper feed tray, the UI control unit 336 requests the paper feed tray management unit 333 to register the paper. In addition, the UI control unit 336 displays on the operation unit 2106 information about the paper whose registration has been completed.

[0043] In this embodiment, the image forming apparatus 103 and the information processing apparatus 101 are provided with print job generation units 301, 321, PDL analysis units 305, 325, and RIP control units 306, 326, respectively. As a result, the description is given so that print job generation, PDL analysis, and RIP control can be performed by both the image processing apparatus and the image forming apparatus. However, these processes for a print job may be performed by either the image processing apparatus. In this embodiment, an example in which these processes are performed by the image processing apparatus 101 will be described.

[0044] Basic operation sequence of printing process (first example) Next, the sequence of the basic operation of the print process will be described with reference to Fig. 4A-1 and Fig. 4A-2. Fig. 4A-1 and Fig. 4A-2 are divided into one figure, and may be referred to collectively as Fig. 4A below. Fig. 4A-1 and Fig. 4A-2 are connected by instructions or notifications with circled numbers 1, 2, and 3. In this embodiment, an example is shown in which the patch type is determined and the patch images are combined by the image processing device 101 or the image forming device 103, but Fig. 4A shows a case in which the patch type is determined and the patch images are combined by the image processing device 101.

[0045] The sequence of Fig. 4A-1 is realized by the CPU 2201 of the image processing apparatus 101 reading a program stored in the ROM 2202 into the RAM 2203 and executing it. Furthermore, the sequence of Fig. 4A-2 is realized by the CPU 2101 of the image forming apparatus 103 reading a program stored in the ROM 2102 into the RAM 2103 and executing it.

[0046] The job generating unit 301 generates a print job by receiving data to be printed and a print instruction from the information processing apparatus 102 via, for example, the communication unit I / F 2208. The job generating unit 301 registers the generated job in the job control unit 303 (S4001).

[0047] The job control unit 303 determines the execution order of the registered jobs and starts execution in sequence (S4002). The job started by the job control unit 303 notifies the page control unit 304 of the start of processing the Nth page (S4003).

[0048] When the page control unit 304 receives the start of processing for the Nth page from the job control unit 303, it issues a RIP instruction to the RIP control unit 306 (S4004). Note that RIP refers to raster image processing, that is, the processing of developing raster image data. This processing is called RIP processing, and the raster image data generated by this is sometimes called RIP data or RIP result.

[0049] The RIP control unit 306 performs RIP processing upon receiving a RIP instruction from the page control unit 304 (S4005). Then, together with the RIP result, the RIP control unit 304 is notified of the toner colors to be used in the image (S4006). For example, when the colors of the original image are converted into toner color components in association with the RIP processing of a page image, color components in which the density of all pixels after conversion is 0 are unused colors, and otherwise the colors are used.

[0050] The page control unit 304 notifies the patch type determination unit 310 of the toner color to be used in the image of the Nth page (S4007). The patch type determination unit 310 determines the patch type (S4008). Then, the page control unit 304 returns the result, i.e., the determined patch type, to the page control unit 304 (S4009). The page control unit 304 instructs the image generation unit 307 to combine patches by specifying the image and patch type (S4010). The image generation unit 307 sends the image, patch type, and patch combination instruction for the image to the patch combination unit 309 (S4011). The patch combination unit 309 combines the image sent from the image generation unit 307 with a patch image (i.e., gradation pattern) of the specified type (S4012). Then, the page control unit 304 transmits the print of the image combined with the patch image to the job control unit 321 (S4013).

[0051] The job control unit 321 transmits the received print job to the page control unit 324 (S4014). When the page control unit 324 receives a command to start processing the Nth page from the job control unit 321, it queries the paper feed tray management unit 333 as to which paper feed tray to use for feeding the specified paper size and paper type for that page (S4015). The paper feed tray management unit 333 determines which paper feed tray to use for feeding paper from based on the specified paper size and paper type (S4016) and returns the result to the page control unit 324.

[0052] The page control unit 324 instructs the paper feed control unit 334 to feed paper from the paper feed stage determined by the paper feed stage management unit 333 (S4017). The paper feed control unit 334 feeds paper from the instructed paper feed stage in accordance with the paper feed instruction from the page control unit 324 (S4018), and notifies the page control unit 324 of the paper feed result (S4019). When the page control unit 324 receives a normal paper feed result from the paper feed control unit 314, it notifies the job control unit 321 that the job control unit 308 can start processing the next page (S4020). In addition, when the job control unit 321 notifies the page control unit 304 of this, the page control unit 304 notifies the job control unit 303 of this (S4021). This makes it possible to start processing the next page.

[0053] After completing S4020, the page control unit 324 instructs the image generation unit 327 to print the image with the combined patches (S4022). When the image generation unit 327 receives a print instruction for the print image, it requests correction information from the correction information storage unit 330 based on the information notified together with the print instruction (S4023). The information notified together with the print instruction may include information indicating the paper type and finishing process. For example, it may be at least one of information indicating the type of paper, such as coated paper or plain paper, and information indicating the type of finish, such as the presence or absence of varnish coating. Since the correction information is determined based on this information, this information may be called, for example, parameter information that specifies the correction information.

[0054] The correction information storage unit 330 searches for correction information, such as gradation correction information, corresponding to the passed information from a storage area, such as the RAM 2203 (S4024). If the correction information storage unit 330 detects the corresponding correction information, it notifies the image generation unit 327 of the correction information (S4025). The image generation unit 327 uses the correction information notified from the correction information storage unit 330 to generate a corrected print image, i.e., a corrected image (S4026).

[0055] On the other hand, if the correction information storage unit 330 cannot find correction information that corresponds to the information passed to it, it notifies the image generation unit 327 that there is no corresponding correction information (S4027). If there is no correction information, the image generation unit 327 generates a print image without correction, i.e., an uncorrected image (S4028). The image generation unit 327 transmits information on the paper feed tray, paper size, and paper type for printing the generated image to the print control unit 335 and issues a print instruction (S4029).

[0056] The print control unit 335 prints the received image (the image with the gradation pattern combined) on paper supplied by the paper feed control unit 334 (S4030). The gradation pattern is also called gradation correction mark information. When printing is complete, the print control unit 335 notifies the page control unit 324 and the colorimetric sensor control unit 332 that printing is complete (paper ejection is complete) (S4031). The notification of printing completion (paper ejection completion) includes information such as the paper feed stage, paper size, and paper type.

[0057] When the page control unit 324 receives a printing completion (paper discharge completion) notification from the print control unit 335, it notifies the job control unit 303 of the completion of processing the Nth page via the job control unit 321 and the page control unit 304 (S4021, S4032).

[0058] Meanwhile, when the color measurement sensor control unit 322 receives a printing completion (paper discharge completion) notification from the print control unit 335, it performs color measurement of the gradation correction mark information (gradation patch) printed in S4030 (S4033). Next, it associates the color measurement result with information such as the paper feed tray, paper size, and paper type notified by the print control unit 335, and notifies the reference information storage unit 331 (S4034).

[0059] The reference information storage unit 331 searches for reference values ​​corresponding to the information such as the paper feed tray, paper size, and paper type notified by the colorimetric sensor control unit 332 stored in the RAM 2203 (S4035). If a reference value corresponding to the notified information is stored, a correction value is calculated from the stored reference value and the colorimetric result notified by the colorimetric sensor control unit 332 (S4036). The correction value may be calculated, for example, by calculating the difference between the colorimetric value and the reference value for each gradation. Next, the reference value information storage unit 331 notifies the correction information storage unit 330 of the calculated correction value (S4037). The correction information storage unit 330 stores the content notified by the reference value information storage unit 331 as correction information (S4038).

[0060] If the corresponding reference value is not stored in S4035, the reference value information storage unit 331 stores the information notified from the colorimetric sensor control unit 332 (colorimetric result, paper feed stage, paper size, paper type, etc.) as a reference value in the RAM 2203 (S4039). For example, the colorimetric value may be associated with the paper feed stage, paper size, and paper type as indexes and stored.

[0061] Here, the processing from S4003 to S4039 is expressed as a loop because it is executed for all pages of the print job registered in the job control unit 303. The start of processing for each page shown in S4003 can be issued when a notification of next page processing start readiness is received in S4009.

[0062] When the job control unit 303 receives the completion of processing the Nth page, it determines whether the Nth page is the final page of the print job (S4040). If the job control unit 303 determines that it has received the completion from the final page, it notifies the print job generation unit 301 of the end of the job (S4041).

[0063] With the above sequence, for each page included in one job, gradation patches corresponding to the color components of each page are synthesized, and the image is formed while correcting with the corresponding correction information. The color measurement values ​​of the gradation patches that have been imaged are then obtained and fed back to the correction information to calibrate the colors. In this case, by synthesizing gradation patches corresponding to the color components of each page, it is possible to strictly manage the number of colors for each page. This also makes it possible to reduce printing costs.

[0064] ●Basic operation sequence of printing process (second example) Next, the sequence of the basic operation of the print process will be described with reference to Fig. 4B. In the sequence of Fig. 4A, the patch type is determined and the patches are combined by the image processing device 101, but Fig. 4B shows a case where the patch type is determined and the patches are combined by the image forming device 103. Note that the same steps or messages as in Fig. 4A are denoted by the same reference numerals.

[0065] 4B is realized by the CPU 2201 of the image processing apparatus 101 reading a program stored in the ROM 2202 into the RAM 2203 and executing it. Furthermore, the CPU 2101 of the image forming apparatus 103 reading a program stored in the ROM 2102 into the RAM 2103 and executing it.

[0066] The job generating unit 301 receives a print job from the I / F and registers the generated job in the job control unit 303 (S4001).

[0067] The job control unit 303 determines the execution order of the registered jobs and starts sequential processing (S4002). The job started by the job control unit 303 notifies the page control unit 304 of the start of processing the Nth page (S4003). When the page control unit 304 receives the start of processing the Nth page from the job control unit 303, it issues a RIP instruction to the RIP control unit 306 (S4004). The RIP control unit 306 receives the RIP instruction from the page control unit 304 and performs RIP (S4005). Then, it notifies the toner color to be used in the image together with the RIP result (S4006). Up to this point, the sequence is the same as in FIG. 4A-1.

[0068] The page control unit 304 receives the RIP result and sends a print and adjustment instruction for the image after RIP to the page control unit 324 of the image forming apparatus 103 (S4057). The page control unit 324 notifies the patch type determination unit 337 of the toner color to be used in the image of the Nth page (S4058). The patch type determination unit 337 determines the patch type (S4059). Then, it returns the result to the page control unit 324 (S4060). The page control unit 324 instructs the image generation unit 327 to combine patches (S4061). The image generation unit 327 sends the image and a patch combination instruction for the image to the patch combination unit 329 (S4062). The patch combination unit 329 performs patch combination on the image sent from the image generation unit 327 (S4063). Then, it sends a print of the combined image to the page control unit 324 (S4064).

[0069] The sequence thereafter is similar to the sequence after S4015 in FIG. 4A-2, and therefore description thereof will be omitted. As in FIG. 4A, steps S4003 to S4039 are repeated for each page until the job is completed. With the above sequence, color management can be achieved in the same manner as the sequence in FIG. 4A. Furthermore, by performing patch determination and patch composition in the image forming apparatus 103, for example, the image forming apparatus 103 can have correction information, and it is possible to reduce the processing load on the image processing apparatus 101 and the required resources.

[0070] ● Clearing reference and correction information Next, a sequence for clearing the reference information and the correction information will be described with reference to Fig. 5. This sequence is realized by the CPU 2101 of the image forming apparatus 103 reading a program stored in the ROM 2102 into the RAM 2103 and executing it.

[0071] When image forming device 103 forms an image on paper, characteristics differ depending on the paper type, so in order for image forming device 103 to perform gradation correction correctly, it is necessary to hold reference information for each paper type. Image forming device 103 supports many paper types, but since the paper to be actually used must be set in a paper feed tray, reference information storage unit 331 holds only reference information for the paper type set in the paper feed tray. Therefore, when a user sets new paper in a paper feed tray of image forming device 103, the reference information and correction information for the paper type that is being removed for replacement are cleared.

[0072] In S5001, the user operates the UI screen of the image forming apparatus 103 and selects a paper feed tray setting screen. In S5002, upon receiving an operation from the user, the UI control unit 336 of the image forming apparatus 103 acquires information on the size and type of paper set in all paper feed trays of the image forming apparatus 103 from the paper feed tray management unit 333. In S5003, the UI control unit 336 displays the information acquired in S5002 on the UI screen. An example screen is shown in FIG. 7(a). In S5004, the user selects the paper feed tray for which he or she wishes to change the paper from the UI screen of the image forming apparatus 103. In S5005, upon receiving an operation from the user, the UI control unit 336 of the image processing apparatus 101 displays on the UI screen a list of paper types that can be set for the selected paper feed tray. An example screen is shown in FIG. 7(b).

[0073] In S5006, the user selects the paper type to be changed from the UI screen of the image forming apparatus 103. In S5007, upon receiving an operation from the user, the UI control unit 336 of the image forming apparatus 103 requests the paper feed stage management unit 333 to register the paper feed stage and paper type selected by the user. In S5008, the paper feed stage management unit 333 updates the information stored in the reference information storage unit 331 and the correction information storage unit 330. A detailed flow will be described later with reference to FIG. 6A.

[0074] When the paper feed tray management unit 313 determines that it is necessary to clear the reference information and correction information based on the flowchart of FIG. 6A, it performs clearing processing in S5009 and S5010. In S5009, the paper feed tray management unit 333 clears the reference information for the paper type to be removed for replacement that was stored in the reference information storage unit 331. Furthermore, in S5010, the paper feed tray management unit 333 determines whether correction information for the paper type to be removed for replacement exists in the correction information storage unit 330, and clears the correction information if it exists. After completing the series of processing in S5008, the paper feed tray management unit 333 performs registration processing of the paper type specified by the user in S5011. In the registration processing, the information of the paper type to be set in the selected paper feed tray is updated. Then, in S5012, the UI control unit 336 is notified of the completion of registration, and in S5013, the UI control unit 336 updates the UI screen with the information of the paper type for which registration has been completed.

[0075] 6A and 6B show a process flow accompanying a change in the paper type registered in each paper feed tray of the image forming apparatus 103. In FIG.

[0076] ● Clearing reference and correction information First, Fig. 6(a) will be described. Fig. 6(a) is a flowchart for describing a method for clearing the reference information and correction information for each paper type registered in the paper feed tray. This sequence is realized by the CPU 2101 of the image forming apparatus 103 reading a program stored in the ROM 2102 into the RAM 2103 and executing it. Furthermore, the paper information set for each paper feed tray is recorded in the RAM 2103, and based on a paper change instruction from the UI control unit 336, the paper feed tray management unit 333 accesses the RAM 2103 and updates the paper information set in each paper feed tray. This flow starts when a notification is received from the UI control unit 336 that the user has launched the screen shown in Fig. 7(a).

[0077] When the paper feed tray management unit 333 receives from the UI control unit 336 that the user has selected a paper feed tray on the screen of FIG. 7(a), selected a paper type on the screen of FIG. 7(b), and pressed the OK button 708, the processing proceeds from step S601 to step S602.

[0078] In step S602, the paper feed tray management unit 333 accesses the RAM 2103 and determines whether there is a paper feed tray whose paper type has been updated. If there is no paper feed tray whose paper type has been updated, the process ends. For example, assume that the paper type of paper feed tray "1" has been changed from "plain paper 1" to "plain paper 3." Then, the paper feed tray management unit 333 detects this change in paper type and proceeds to step S603. In step S603, the paper feed tray management unit 333 accesses the RAM 2103 and determines whether the same type of paper as that set in the paper feed tray whose paper is to be changed is set in the other paper feed trays. If the same type of paper is set in the other paper feed trays, the process proceeds to step S605. If the same type of paper is not set in the other paper feed trays, the process proceeds to step S604.

[0079] In step S604, since the paper type before the change will no longer be used in all paper feed trays, the paper feed tray management unit 333 instructs the reference information storage unit 331 and the correction information storage unit 330, which manage the reference value and correction value information of the paper, to delete the reference value and correction value information. This process corresponds to S5009 and S5010 in FIG. 5. The reference value and correction value information corresponds to TBL881A and TBL883A, which will be described later. Then, the process proceeds to S605. In S605, the paper feed tray management unit 333 instructs the reference information management unit 331 and the correction information storage unit 330 to delete the paper type information of the paper feed tray to be changed for each record from the reference value management table (FIG. 8D(d)) and the correction value management table (FIG. 8D(e)). Then, the process ends.

[0080] ●Registering standard information and correction information Next, FIG. 6(b) will be described. FIG. 6(b) is a flowchart for describing a method for registering reference information and correction information for each paper type. This procedure corresponds to S4035 to S4039 in FIG. 4A-2. The reference information storage unit 331 has a reference value (TBL881A in FIG. 8C described later) in the RAM 2103. The correction information storage unit 330 also has a measurement value (TBL882A described later) in the RAM 2103. Also, a table (TBL883A described later) that stores correction values ​​from measurement values ​​and reference values ​​is stored in the RAM 2103. This sequence is realized by the CPU 2101 of the image forming apparatus 103 reading a program stored in the ROM 2102 into the RAM 2103 and executing it. This flow starts when the basic information storage unit 331 receives a notification of the color measurement result from the color measurement sensor control unit 332.

[0081] In step S620, the reference information storage unit 331 records the acquired color measurement results in the measurement value TBL882A of the RAM 2103. Then, the reference information storage unit 331 associates the color measurement results with the paper feed stage number from which the color measurement results were obtained and stores the color measurement results in the RAM 2103. Then, the process proceeds to step S621. In step S621, the reference information storage unit 331 accesses the RAM 2103 and determines whether the paper feed stage number linked to the color measurement results notified by the color measurement sensor control unit 332 is registered as a record in the target paper feed stage 892 in the reference value management table (FIG. 8D(d)). If it is not registered, the process proceeds to S622. If it is registered, the process proceeds to S626. First, the case where the process proceeds to S622 will be described.

[0082] In step S622, the reference information storage unit 331 accesses the reference information management table (FIG. 8D(d)) and determines whether the paper type associated with the color measurement result notified from the color measurement sensor control unit 332 is registered in another paper feed stage. If it is not registered in another paper feed stage, the process proceeds to step S623. If it is registered in another paper feed stage, the process proceeds to step S625. First, the case where the process proceeds to S623 will be described.

[0083] In step S623, the reference information storage unit 331 stores the color measurement result notified from the color measurement sensor control unit 332 as a reference value (TBL881A described later). Then, the process proceeds to step S624. In step S624, the reference information storage unit 331 adds a record of the paper feed tray linked to the color measurement result notified from the color measurement sensor control unit 332 to the reference value management table (FIG. 8D(d)), performs link processing that references the reference value stored in S623, and ends. Specifically, if the table referenced by the reference value of the paper type "plain paper 3" is TBL881A, the paper type is entered as "plain paper 3" in the paper type 891 column of the reference management table (FIG. 8D(d)). Furthermore, "(Link) present TBL881A" is entered in the reference value 894 column as link information to the reference value. Then, the process ends.

[0084] On the other hand, if it is found in step S622 that the record is registered in another feed tray, the process proceeds to step S625. In step S625, the reference information storage unit 331 copies a record of the same paper type already registered in the reference information management table (FIG. 8D(d)) as a record of the feed tray linked to the color measurement result to the reference information management table (FIG. 8D(d)). However, the fields to be copied are those excluding the target feed tray column 892. Information identifying the specified feed tray is stored in the target feed tray column 892. This means that the reference value of the paper type of the specified feed tray is saved. Then, the process proceeds to step S626. The process also branches to step S626 if, in step S621, the feed tray number linked to the color measurement result is registered as a record in the target feed tray 892 of the reference value management table.

[0085] In step S626, the reference information storage unit 331 calculates a correction value from the measurement value (TBL882A described below) and the reference value (TBL881A described below). The correction value is obtained, for example, by subtracting the measurement value of the corresponding patch from the reference value of a specific density of a specific color. Then, the process proceeds to step S627. In step S627, the reference information storage unit 331 notifies the correction information storage unit 330 of the result calculated in step S626. On receiving this notification, the correction information storage unit 330 stores the value in a correction value (TBL883A described below). Then, the process ends.

[0086] ●Paper type registration screen 7, a screen for registering a paper type to a paper feed tray of the image forming apparatus 103 will be described based on the procedure in Fig. 5. Fig. 7(a) shows the paper feed tray setting screen displayed by the UI control unit 336. When the user calls up the paper feed tray setting screen (S5001), the UI control unit 336 queries the paper feed tray management unit 333 for setting information of the current paper feed tray (S5002), and the result is displayed on the screen 700 (S5003).

[0087] The user selects the paper feed tray for which the paper type is to be set on screen 700. In this embodiment, selection buttons 701 to 704 are assigned to the four paper feed trays. After selecting a specific paper feed tray, the user presses a setting button 705 for setting the paper type (S5004), and calls up the paper type setting screen 710 (b) (S5005).

[0088] On the paper type selection screen 710, the user selects one that matches the paper type that has been / will be set in the paper feed tray selected on screen 700. In the example of FIG. 7(b), Plain Paper 1 is replaced with Plain Paper 3 (S5006). Pressing the OK button 708 returns to screen 700. On screen 700, the user confirms that the paper type has been changed and presses the OK button 706. The UI control unit 336 notifies the paper feed tray management unit 333 of the user's settings (S5007) and makes a registration request (S5008).

[0089] ●Maintaining correction values ​​and reference values Next, the printing position of the gradation correction mark information (gradation patch) for gradation correction in this embodiment, the colorimetric sensor that measures the printed color patch, the signal value from the colorimetric sensor, and the method of retaining the correction value derived from the signal value will be described with reference to Figures 8A, 8B, 8C, 8D, 8E, 8F, and 8G.

[0090] 8A will be described. An output example of gradation correction mark information (gradation patch) for real-time gradation correction in this embodiment is shown at 800. Patches required for real-time multi-tone correction are printed on the inside of the printing paper 800, and in a margin defined outside the guaranteed print area 801 of the paper. The guaranteed print area is the part that becomes the final product, and is an area where printing of the user's image is guaranteed. On the other hand, there is an area outside the guaranteed print area where an image can be formed, but it is assumed that it will be cut and removed as a final product. Therefore, in a POD machine, the outside of the guaranteed print area is used for printing various patches required for image quality adjustment and information required for inspection.

[0091] In this embodiment, the patches for real-time tone correction are printed in a line outside the print guaranteed area, and the colorimetric sensors 861 and 862 on the printing surface side read the patches. Therefore, the patches of each color are aligned parallel to the conveying direction in accordance with the position of the colorimetric sensor. On the printing paper 800, 10 patches of each of the toner monochromatic densities of the cyan tone patch 810, the magenta tone patch 850, the yellow tone patch 830, and the black tone patch 840 are printed in 10% increments, totaling 40 patches. For example, the cyan color patch 820 has a density of 100%, and the density decreases in 10% increments thereafter, with the patch 829 having a density of 10%. The magenta, yellow, and black colors also each have the same 10 patches in one set, and basically, feedback information required for tone correction is generated using the reference value and measurement value data for the four colors. The tone correction patches are synthesized by the patch synthesis unit 309 into the generated image of the image generation unit 307.

[0092] In this embodiment, it is also possible to print gradation patches of only the toner color used on a page. For example, if the only toner color used on a page is cyan, 10 single-color cyan patches are printed in 10% density increments in gradation patch 810. Then, since gradation patches 830, 840, and 850 are toner colors that are not used, control is performed so that gradation patches of these colors are not printed.

[0093] In addition, in this embodiment, the area where the unused toner color was supposed to be printed may be used, and the density difference, reference value, and measurement value of each patch of the used gradation patch may be switched to a finer one, thereby increasing the feedback information required for gradation correction. This allows for more detailed correction. For example, when the toner used on a page is only cyan, if a gradation patch 810 of only cyan, which is the color used, is printed, the areas of the gradation patches 830, 840, and 850 become blank areas. In this embodiment, the cyan gradation patch used on the page is also printed in these areas. In this specification, "gradation" may be written as "tone", but both terms indicate a level of shading and are synonymous.

[0094] Specifically, in this case, since the only toner color used is cyan, a cyan gradation patch is generated with 40 levels of density. Then, the gradation patch with 40 levels of density is divided into four, for example, every 10 levels, and each is printed in the area of ​​gradation patches 810, 830, 840, and 850. At this time, the reference values ​​and measured values ​​are also set in 40 levels. This makes it possible to perform more fine-grained gradation correction than when gradation correction is performed in 10 levels.

[0095] FIG. 8B will be described. FIG. 8B is a cross-sectional view of the conveying path in the image forming apparatus of FIG. 8A, seen from the side. After toner is transferred to the printing paper 800 by developing devices 871 to 874 of the respective colors of CMYK and fixed by a fixing device 875, gradation patches 810, 830, 840, 850 are read by colorimetric sensors 861, 862 installed on both the left and right ends in the conveying direction. The colorimetric sensors are installed on the printing surface side. Note that since the position of the gradation patches varies depending on the size of the paper, the colorimetric sensors may be arranged for each size, and the colorimetric sensor to be used may be changed depending on the size of the paper being conveyed, or the colorimetric sensor may be configured to be movable depending on the paper size.

[0096] ● Reference values, measured values, and correction values FIG. 8C shows an example of a reference value, a measurement value, and a correction value generated based on the CMYK density information scanned by the colorimetric sensors 861 and 862. The reference value is a value that is a reference for determining the CMYK density information. The measurement value is a value that is generated based on the reference value and indicates the density when a patch printed on a paper surface is read by the colorimetric sensor. The correction value is a value calculated by finding the difference between the reference value and the colorimetric value. As shown in FIG. 8A, a total of 40 patches, 10 for each CMYK, are printed on the printing paper 800, and 40 measurement values ​​are obtained by reading this with the colorimetric sensor. In this embodiment, the sensor control unit 332 digitizes the patch density of the colorimetric sensor in 1024 steps and stores it.

[0097] The color measurement results notified from the sensor control unit 332 are stored in the reference information storage unit 331 as reference values ​​for each paper type set in the paper feed tray. The color measurement results need to be managed for each paper type. If the color measurement results of the paper notified from the sensor control unit 332 are for paper that has not been registered in the reference information storage unit 331, the color measurement results of 40 points are stored as new "reference values" 881A. If the color measurement results of the paper notified from the sensor control unit 332 are for paper that has been registered in the reference information storage unit 311, the color measurement results are treated as new "measured values" 882A, and a correction value 883A is calculated from the difference between the reference value and the measured value. The correction value is stored in the correction information storage unit 330. Note that in this embodiment, the correction values ​​are stored, but the measured values ​​may be stored and the correction values ​​may be calculated each time from the difference between the reference value and the measured value.

[0098] FIG. 8C is an example when all CMYK patches are printed. As mentioned above, when printing patches of only the toner colors used on a page and when printing patches of the same color in multiple locations, patches with a density set finer than 10% are used. FIG. 8E is an example of reference values, measurement values, and correction values ​​used when printing patches of the same color in two locations. In this case, the density of the patches printed in two locations is generated in 20 steps, printed, and gradation correction is performed. FIG. 8F and FIG. 8G are examples of reference values, measurement values, and correction values ​​used when printing patches of the same color in three locations and four locations, respectively.

[0099] Correction value management table and reference value management table 8D(d) is a table for managing reference values ​​by the reference information storage unit 331. The record information is made up of the following items: paper type 891, target paper feed stage 892, reference value (1 / 2 speed) 893, reference value (1 / 1 speed) 894, generated page ID 895, and timestamp 896.

[0100] Figure 8D(d) shows an example in which Plain Paper 3 is loaded in Paper Feed Stage 1, and later, during printing processing for the 60,014th page cumulatively since power-on at 10:04:06 on 2019 / 07 / 18, "Plain Paper 3" is fed from "Paper Feed Stage 1" at "1 / 1 speed." In other words, this is an example in which the print results in this case are registered as colorimetric reference values. Reference values ​​893 and 894 are registered with links to the reference values ​​and correction value table, rather than the reference values ​​themselves. If "Plain Paper 3" is removed from "Paper Feed Stage 1," the record information is deleted.

[0101] 8D(e) is a table in which the correction information storage unit 330 manages the correction values. The basic structure of the table is the same as the reference value management table, except that the reference value is replaced with the correction value. When the paper is removed from the target paper feed tray 897, the record information is deleted. Job attribute setting screen 9 shows a screen (UI) for setting job attributes to be set for a print job. This UI is displayed on the operation unit 2206 when the CPU 2201 reads out a program stored in the ROM 2202 and instructs the operation unit I / F 2205. The user operates the operation unit 2206 to select the executed job and display this UI 900 on the operation unit. Each attribute will be described below.

[0102] A color mode selection section 901 is a section for designating a color mode. CMYK 902 indicates that the print job image is to be processed using all the colors of CMYK. Grayscale 903 indicates that the print job image is to be processed using K toner.

[0103] A color specification section 904 is a section for issuing instructions to specify the color to be used and process the print job. For example, if the user checks 905, the print image is processed so that it is printed using only cyan toner. In this way, the user can specify the color to be used on a job-by-job basis. During RIP processing, the specified color is referenced and a raster image is generated using only the specified color.

[0104] The patch setting section 909 is a section for specifying the gradation patch to be used for automatic adjustment. When the user selects the adjustment mark specification 910, the image forming device reads the patch and executes correction processing for the print job. The adjustment mark is the same as the gradation patch. When the user selects the all colors specification 911, patches of each color of CMYK are printed on all pages generated by the print job processing. When the user selects the used colors specification 912, only the colors used on each page processed by the print job are printed as correction patches. The all margin specification 914 specifies that when the used colors specification 912 is selected, if there is one or more unused toner colors in CMYK, a patch of the color used on that page is printed in the area where it would normally be printed.

[0105] In addition, the priority color designation 915-918 designates which color to be used on the page is to be printed as a patch with priority when there is a toner color that is not used. When CMYK 902 is selected in the color mode selection section 901 and one of cyan 905-yellow 908 is selected in the color designation section 904, only the color selected in the color designation section 904 can be designated in the priority color designation 915-918. For example, assume that the user selects CMYK 902, cyan 905, adjustment mark designation 910, color designation to be used 912, and all margin designation 914, and inputs 1 only to cyan 915 among cyan 915-yellow 918. In this case, only cyan is used as the toner. That is, yellow, black, and magenta are not printed on the gradation patches 830, 840, and 850 in FIG. 8A, respectively. In this case, the patch with 40 levels of density as shown in FIG. 8G is divided into 10 levels each and printed in four places. The selection and layout method of the patches will be described later.

[0106] When the user selects the OK button 919, the UI control unit 308 detects this, writes the specified job attributes to the RAM 2203, and ends the process.

[0107] Print Jobs Next, the print jobs used in this embodiment will be described. Fig. 10(a) is a job storage table. The job storage table 1001 is stored in, for example, the RAM 2203. The print jobs are transmitted from the information processing device 102. When the user instructs the image processing device 101 to generate and execute a print job, the print job generation unit 301 accepts this and records the print order and the print job names in the job storage table 1001 in the order of acceptance.

[0108] 10B shows a job attribute table. The job attribute table 1002 is stored in, for example, the RAM 2203. When the job control unit 303 accepts the registration of a print job from the print job generation unit 301, it reads the attributes specified for the job and writes them into the job attribute table 1002. In the job attribute table 1002, the contents written in each column are as follows:

[0109] Column [1]: Job name. [2] Column: Color mode (based on the designation in the color mode selection section 901 in FIG. 9). [3] Column: Specified color (based on the specification in the color specification section 904). [4] Column: Whether or not automatic adjustment is performed (based on the specification of the adjustment mark specification 910). [5] Column: Patch mark printing method (based on the specification of all colors specification 911 or usage color specification 912). [6] Column: Whether or not there is a specification for printing patches to be used on the page in the margin area (based on the specification of full margin specification 914). Columns [7] to

[10] : Based on the designation of Shian 915 to Yellow 918. Valid when column [6] is "Yes".

[0110] The above job attributes may be transmitted to the image processing apparatus 101 (in the case of FIG. 4A) or further transmitted to the image forming apparatus 103 (in the case of FIG. 4B) and may be referenced for generating the patch arrangement table of FIG.

[0111] Example of gradation patch placement 11 is a patch arrangement table showing an example of the toner color used for each page in a print job and the type of patch to be printed in each patch printing area. Each table is stored in, for example, the RAM 2203. This table may be generated by the print job generation unit 301, or may be generated by the page control unit 304 or the page control unit 324. This table is generated based on the color of each page and the job attributes, and may be referenced in determining the patch type and combining patches.

[0112] The contents of each column in each table are as follows: [1] Column: Page number. [2] Column: Toner color used. [3] Column: Patch type to print in area 1 (810) (default patch color: C). [4] Column: Patch type to print in area 2 (830) (default patch color: Y). [5] Column: Patch type to print in area 3 (840) (default patch color: K). [6] Column: Patch type to print in area 4 (850) (default patch color: M).

[0113] Incidentally, for the colors of the patches printed in columns [3] to [6], a default patch color is defined. The default patch color is as described above. The method of determining the patch type will be described in the flowchart of FIG. 12. The patch types used here will be described. As described in FIG. 8C, in this embodiment, the type of patch to be printed is switched according to the number of areas where patches of the same color are printed. In FIG. 11, each cell indicates the color and the number of gradations of the gradation patch. The color is indicated by the first letter of the color, and the number of gradations is indicated by the value in the tens digit. For example, when printing patches of the same color in two places, the density of the patch to be used is generated in 20 steps. For example, when using a patch generated in 20 steps for magenta, "M2" is written in the cell indicating the area where this is printed in the table of FIG. 11 (for example, [b][5] and [b][6] in table 1104).

[0114] Moreover, when a cyan patch generated in 30 levels of patch density is used, it is noted as "C3" in the table of FIG. 11 (for example, [a][3] to [a][5] in table 1105). Furthermore, when a black patch generated in 40 levels of patch density is used, it is noted as "K4" in the table of FIG. 11 (for example, [a][3] to [a][6] in table 1107). Furthermore, when a yellow patch generated in 10 levels of patch density is used, it is noted as "Y1" in the table of FIG. 11 (for example, [c][6] in table 1104). Of course, these notations are for explanatory purposes only, and in reality, they may be corresponding unique codes. In this way, for a color in which gradation patches are combined in multiple regions, for a gradation patch to be combined in one region, a gradation patch with a number of gradations according to (proportional to) the number of regions is divided by the number of regions and placed in each region.

[0115] ●Decision process for placing patches on pages FIG. 12 is a flowchart for determining the patch type (patch type according to patch color and density level) and its layout described in FIG. 11. Each step of the flowchart shown in FIG. 12 is realized by the CPU 2201 reading out a program stored in the ROM 2202. The process of FIG. 12 corresponds to the details of the process from S4004 in FIG. 4A-1 to S4008 in FIG. 4A-2, or from S4004 to S4059 in FIG. 4B. The symbol "S" in the description of each process indicates a step in the flowchart. The process of FIG. 12 is performed by sequentially focusing on the print jobs stored in the job storage table 1001 in FIG. 10(a) in the order of printing, and the focused print job (referred to as a focused job or a target job) is processed. This process creates a patch arrangement table exemplified in FIG. 11.

[0116] First, it is determined whether or not "automatic setting" is specified in the job attributes of the target job. This is done, for example, by determining whether the value in the "automatic setting" column of the job attribute table 1002 in FIG. 10(b) is "Yes". If automatic setting is not specified, tone patches are not printed on each page, and the procedure in FIG. 12 does not need to be executed. If it is set to "Yes", the job control unit 303 instructs the page control unit 304 to start page processing, and starts the flow in FIG. 12. To start FIG. 12, first focus on the first page of the target job. This is called the page of interest or the target page.

[0117] In step S1201, the page control unit 304 determines whether any unprocessed pages remain. If there are no unprocessed pages, the process ends. In step S1201, if there are any unprocessed pages, the process advances to step S1202, with the top page of the unprocessed pages being the page of interest. In step S1202, the RIP control unit 306 develops the page into a raster image and determines the toner color to be used for the page of interest. Then, the toner color to be used is recorded in the toner color to be used column of the patch arrangement table shown in FIG. 11. Then, the process advances to step S1203.

[0118] In step S1203, the page control unit 304 instructs the patch type determination unit 310 to determine the patch type to be used. The patch type determination unit 310 accesses the mark printing method in the job attribute table 1002, and determines whether "CMYK patch printing on all pages" is selected. If it is selected, the process proceeds to step S1204. If it is not selected, the process proceeds to step S1205.

[0119] In step S1204, the patch type determination unit 310 specifies that patches (C1, Y1, K1, M1) generated with 10 levels of density are to be printed in colors defined as default colors for each area where gradation patches are to be printed. Specifically, the codes C1, Y1, K1, and M1 indicating the color and gradation are written as patch types for each area in the patch arrangement table. Then, the process proceeds to step S1201.

[0120] In step S1205, the "patch printing in remaining area" column of the job attribute table 1002 is accessed to determine whether or not it is set. If it is not set, the process branches to S1206, and if it is set, the process branches to S1208.

[0121] In S1206, the patch type determination unit 310 accesses the toner color used column (already written in S1202) of the patch arrangement table shown in FIG. 11. The toner color used is then temporarily recorded in the RAM 2203. Then, the process proceeds to step S1207. In step S1207, the patch type determination unit 310 accesses the RAM 2203 and reads out the toner color used in patch printing. Then, depending on the number of colors, a code corresponding to the color to be used from among C1, Y1, K1, and M1 is recorded in the column of the area corresponding to the color to be used from among the default areas of C, Y, K, and M in the patch arrangement table 1102. Here, in step S1207, the patch type determined is a gradation patch with a density gradation of 10 levels for all colors. After this, the process branches to step S1201.

[0122] If a setting has been made to print patches in the remaining area, in S1208, it is determined whether the colors used on the page of interest are the four colors of CMYK. If it is determined that the colors used are four colors, the process branches to S1206 since tone patches of each color are composited in the default area. If it is determined that the colors used are not four colors, the process branches to S1209. Note that if it is determined in step S1208 that the toner used is four colors, the process may also branch to step S1204.

[0123] In step S1209, the patch type determination unit 310 accesses the patch printing priority order in the job attribute table 1002 and determines whether it has been set. If it has been set, the process branches to step S1210. If it has not been set, the process is treated the same as if it had not been set to print patches in the remaining area, and the process branches to S1206.

[0124] If a priority order has been set, in step S1210, the patch type determination unit 310 accesses the patch arrangement table, obtains the number of toner colors to be used, and subtracts this value from "4", which is the number of areas in which patches can be printed. This value, i.e., the number of remaining areas in which patches of the same color can be printed, is temporarily recorded in RAM 2203, and the process proceeds to step S1211. In step S1211, the patch type determination unit 310 determines the color of the color patch to be used, and also temporarily records this in RAM 2203. In step S1211, the toner color that has been designated as a priority order and is to be used on the page is determined as the color of the gradation patch to be arranged in the remaining area.

[0125] In step S1212, the patch type determination unit 310 refers to the remaining area numbers and colors recorded in steps S1210 and S1211 in the RAM 2203, and records the arrangement of the gradation patches in the patch arrangement table of FIG. 11. In step S1212, gradation patches of the colors with the specified priorities are arranged in the order of priority in the number of free areas determined in S1210. First, the gradation patches of the used colors for which no priority is specified are arranged in the default areas at density gradation 10. Next, the colors of the free areas are determined according to the priorities. For example, the order of the areas may be determined in advance to decide which color for which area. The free areas may be selected according to the predetermined order, and for the selected free areas, the color of the gradation patch to be arranged may be determined according to the specified priority. Determining the color of the free area may be, for example, writing the symbol of the corresponding color in the column of the free area in the patch arrangement table. If there are still free areas left even after determining the areas for arranging all the colors with specified priorities, the determination of the area for arranging is repeated by returning to the color with the highest priority. When the colors are determined for all the free areas, the number of areas where each color is arranged is counted. The counted number becomes the tens digit of the density gradation of the gradation patch of the color arranged in that area. Therefore, this number is additionally recorded immediately after the color symbols (Y, M, C, K) recorded in the patch arrangement table. Thus, the patch arrangement table is completed. Next, a specific example will be described with reference to the job attribute table 1002 shown in FIG. 10 and the patch arrangement table illustrated in FIG. 11.

[0126] <Regarding the processing of Job1> The job control unit 303 processes the jobs registered by the print job generation unit 301 in the order listed in table 1001. It starts processing the print job name "Job1" in print order "1" listed in table 1001. It then instructs the PDL analysis unit 305 to write the job attributes specified for the job in row [a] of table 1002. It then confirms that auto adjustment is set to "Yes" in [a][4]. The job control unit 303 then instructs the page control unit 304 to start page processing, and starts this flow.

[0127] In step S1201, the page control unit 304 checks whether any pages remain to be processed. If there are no pages remaining, the process ends. If there are any pages remaining in step S1201, the process proceeds to step S1202. In step S1202, the RIP control unit 306 RIPs the page and determines the toner colors to be used. Then, the toner colors to be used are entered as "C, M, Y, K" in cell [a][2] of table 1101. Then, the process proceeds to step S1203. In step S1203, the page control unit 304 instructs the patch type determination unit 310 to determine the patch type to be used. The patch type determination unit 310 accesses [a][5] of table 1002 and checks that "CMYK patch printing on all pages" is selected. Then, the process proceeds to step S1204.

[0128] In step S1204, the patch type determination unit 310 designates to print patches (C1, Y1, K1, M1) that are defined as default colors and generated with 10 density levels in each area where patches are to be printed. Specifically, it writes to [a][3] to [a][6] of the table 1101. Then the process proceeds to step S1201. After that, the processing for the second page is performed, and the process proceeds through steps S1202, S1203, and S1204. Since [a][5] of "Job1" designates to "print CMYK patches on all pages", patches (C1, Y1, K1, M1) that are defined as default colors and generated with 10 density levels are printed on every page. When there are no remaining pages in step S1201, the process ends. After that, the image with the synthesized patches is subjected to the correction process shown in FIG. 8C by the colorimetric unit 210 provided in the image forming apparatus 103, but the details are omitted.

[0129] <Regarding the processing of Job2> Next, the job control unit 303 starts the processing of the print job name "Job2" with the print order "2" described in the table 1001. Then, it instructs the PDL analysis unit 305 to describe the job attributes specified in the job in the [b] row of the table 1002. Then, it confirms that it is set to "yes" for automatic adjustment in [b][4]. Then, when the job control unit 303 instructs the page control unit 304 to start page processing, this flow starts.

[0130] In step S1201, the page control unit 304 checks whether any pages remain to be processed. Thereafter, the process proceeds to steps S1201 and S1202, but the details have already been explained and will be omitted. In S1202, the toner colors to be used for page number "1" of "Job2" are entered as "C, M" in [a][2]. Then, the process proceeds to step S1203. In step S1203, the page control unit 304 instructs the patch type determination unit 310 to determine the patch type to be used. The patch type determination unit 310 accesses [b][5] of the table 1002 and checks whether "print CMYK patches on all pages" is specified. Since [b][5] of the table 1002 states "print only patches of colors used on the page," the process proceeds to step S1205.

[0131] In step S1205, the patch type determination unit 310 checks [b][6] in the table 1002 and checks the value of patch printing in the remaining area. In this example, the value is "none", so the process proceeds to step S1206. In step S1206, the patch type determination unit 310 accesses [a][2] in the table 1102, checks that the toner colors to be used are two colors, "C, M", and records in the RAM 2203 that the patch will be printed in two colors, "C, M". Then, the process proceeds to step S1207. In step S1207, the patch type determination unit 310 accesses the RAM 2203 and reads out the toner colors "C, M" to be used in patch printing. Then, these colors are recorded in the table 1102 so that the patches generated with 10 levels of density are printed in the area defined by default.

[0132] Specifically, the toner color "C" to be used is defined as the default color at 810. Therefore, a patch "C1" with a density of 10 levels is recorded in cell [a][3] of area 1 where "C" is defined as the default color. Similarly, a patch "M1" with a density of 10 levels is recorded in cell [a][6] of area 4 where "M" is defined as the default color. Then the process proceeds to step S1201. After this, the process proceeds through steps S1201, S1202, S1203, S1205, S1206, S1207, S1201, but the details have been explained and are thus omitted. At S1201, if there are no more pages to process, the page control unit 304 ends the process.

[0133] <Regarding the processing of Job3> Next, the job control unit 303 starts the processing of the print job name "Job3" with the print order "3" described in table 1001. Then, it instructs the PDL analysis unit 305 to record the job attributes specified in the job in row [c] of table 1002. And it is confirmed that it is set to "yes" for automatic adjustment in [c][4]. Then, when the job control unit 303 instructs the page control unit 304 to start page processing, this flow starts. At step S1201, the page control unit 304 checks if there are any pages left to process. Thereafter, the process proceeds through steps S1201 and S1202, but the details have been explained and are thus omitted.

[0134] At step S1202, the toner colors to be used for page number "1" of "Job3" are described as "C,M" in [a][2]. Then the process proceeds to step S1203. In this example, since the specified colors are described as "C,M" in [c][3] of table 1002, even if the input image contains Y and K, the printed image after RIP will be in two colors, "C" and "M". There are various methods for converting the output signal with respect to the input signal, but the detailed description is omitted. Thereafter, the process proceeds through steps S1203, S1205, S1206, S1207, S1201, but the details have been explained and are thus omitted. At S1201, if there are no more pages to process, the page control unit 304 ends the process.

[0135] <Regarding the processing of Job4> Next, the job control unit 303 starts the processing of the print job name "Job4" with the print order "4" described in the table 1001. Then, it instructs the PDL analysis unit 305 to describe the job attributes specified for the job in the [d] row of the table 1002. And it confirms that "yes" is set for [d][4] for automatic adjustment. Then, when the job control unit 303 instructs the page control unit 304 to start page processing, this flow starts.

[0136] In step S1201, the page control unit 304 checks whether there are pages left to be processed. Thereafter, the processing proceeds to steps S1201, S1202, S1203, and S1205, but the details have been explained and are thus omitted. In step S1205, the patch type determination unit 310 checks [d][6] of the table 1002 and checks the patch printing value for the margin area. In the case of this example, since the value is "yes", the processing proceeds to step S1208.

[0137] In step S1208, the patch type determination unit 310 accesses [a][2] of the table 1104 and checks the toner color to be used. Here, when the toner color to be used is the CMYK four colors, the processing proceeds to step S1206. That is, when the patch printing area is four places and CMYK four-color patches are to be printed, only one patch of each color can be printed. In this case, in S1206, it is controlled such that CMYK four-color patches are printed. The details have been explained and are thus omitted. Return the explanation to step S1208.

[0138] In step S1208, the toner color to be used is described as "C" in [a][2] of the table 1104. In this case, the process proceeds to step S1209. In step S1209, the patch type determination unit 310 accesses [d][7] to [d]

[10] of the table 1002 to check whether there is a patch to be printed in the remaining area. If there is no description of a patch to be printed in the remaining area, the process proceeds to step S1207. That is, the operation is the same as when a patch is not printed in the remaining area. In step S1209, if there is a patch to be printed in the remaining area, the patch color and the priority order are read out and recorded in the RAM 2203. In this example, "C", "M", and "Y" are recorded in the RAM 2203 in descending order of priority. Then, the process proceeds to step S1210.

[0139] In step S1210, the patch type determination unit 310 accesses [a][2] of the table 1104 and confirms that the number of toner colors to be used is "1". Then, the patch type determination unit 310 subtracts the number of toner colors to be used "1" from the number of areas in which patches can be printed "4", records in the RAM 2203 that the number of remaining areas in which patches of the same color can be printed is "3", and proceeds to step S1211. In step S1211, the patch type determination unit 310 accesses the RAM 2203 and extracts toner colors that have a priority order and are to be used on the page. In this example, the toner colors that have a priority order are "C", "M", and "Y", and only "C" is to be used on the page. Therefore, only "C" is set as the patch color to be printed in multiple places and written to the RAM 2203. Then, the process proceeds to step S1212.

[0140] In step S1212, the patch type determination unit 310 accesses the RAM 2203 and confirms the toner color to be used and the patch color to be printed in multiple locations. In this example, the toner color to be used is "C", and the patch color to be printed in multiple locations is "C". When one color of toner is used and patches of that color are laid out in multiple locations, the patches can be laid out in four locations where patch printing is possible. In this case, "C4" is entered in [a][3] to [a][6] of the table 1104 so that the patches with 40 levels of density shown in FIG. 8G are printed at 810, 830, 840, and 850. Then, the process proceeds to step S1201.

[0141] In S1201, since there are pages remaining to be processed, the page control unit 304 advances the process to step S1202, and the process thereafter advances to steps S1202, S1203, S1205, S1208, S1209, and S1210, the details of which have already been explained and will be omitted here. In step S1210, the patch type determination unit 310 accesses [b][2] in table 1104 and confirms that the number of toner colors used is "2". Then, the number of areas in which patches can be printed, "4", is subtracted by "2", which is the number of toner colors used, and the fact that the number of remaining areas in which patches of the same color can be printed is "2" is recorded in the RAM 2203, and the process advances to step S1211.

[0142] In step S1211, the patch type determination unit 310 accesses the RAM 2203 and extracts the toner colors that have priority designation and that are to be used on the page. In this example, the toner colors that have priority designation are "C", "M", and "Y", and the toner colors to be used on the page are two colors, "C" and "M". Therefore, "C" and "M" are designated as patch colors to be printed in multiple locations, and are written to the RAM 2203. Then, the process proceeds to step S1212.

[0143] In step S1212, the patch type determination unit 310 accesses the RAM 2203 and confirms the toner color to be used and the patch color to be printed in multiple locations. In this example, the toner colors to be used are "C" and "M", and the patch colors to be printed in multiple locations are "C" and "M". When two toner colors are used and patches of those colors are laid out in the remaining two locations, each patch can be laid out in one location. In other words, both "C" and "M" can be printed in two locations in total, one location printed by default and one additional location. In this case, the patch with 20 levels of density shown in FIG. 8E is selected. More specifically, "C2" is written in [b][3] and "M2" is written in [b][6] so that "C" is printed in area 1 (810) where "C" is printed by default, and "M" is printed in area 4 (850) where "M" is printed by default. Also, to print this patch in area 2 (830) and area 3 (840) where "Y" and "K" are defined by default, "C2" is entered in [b][4] and "M2" is entered in [b][5] of table 1104. Then, the process proceeds to step S1201.

[0144] In S1201, since there are pages remaining to be processed, the page control unit 304 advances the process to step S1202, and the process thereafter advances to steps S1202, S1203, S1205, S1208, S1209, and S1210, the details of which have already been explained and will be omitted here. In step S1210, the patch type determination unit 310 accesses [c][2] in the table 1104 and confirms that the number of toner colors used is "3". Then, the number of areas in which patches can be printed, "4", is subtracted by "3", and the fact that the number of remaining areas in which patches of the same color can be printed is "1" is recorded in the RAM 2203, and the process advances to step S1211.

[0145] In step S1211, the patch type determination unit 310 accesses the RAM 2203 and extracts the toner colors with specified priorities and the toner colors used for the page. In the case of this example, the toner colors with specified priorities are "C", "M", and "Y", and the toner colors used for the page are the three colors "C", "M", and "Y" in the order of highest priority. Here, since the number of remaining areas where patches of the same color can be printed is "1", only the most prioritized "C" is used as the patch color to be printed at multiple locations and written to the RAM 2203. Then the process proceeds to step S1212.

[0146] In step S1212, the patch type determination unit 310 accesses the RAM 2203 and checks the toner colors to be used and the patch colors to be printed at multiple locations. In the case of this example, the toner colors to be used are "C", "M", and "Y", and the patch color to be printed at multiple locations is "C". In this case, since "C" can be laid out at two locations, the patches with 20 density levels shown in FIG. 8-(c)-2 are selected. Also, for "M" and "Y", since they can be laid out at one location, the patches with 10 density levels shown in FIG. 8C are selected. More specifically, for "C", "C2" is noted in [c][3] and [c][5] of the table 1104 so that it is laid out in the area 1 (810) where it is printed by default and in the area where "K" not used on this page is defined by default. Also, for "Y" and "M", "Y1" is noted in [c][4] and "M1" is noted in [c][6] of the table 1104 so that these colors are printed in the area 1 (830) and area 4 (850) where they are defined by default. Then the process proceeds to step S1201. At S1201, if there are no more pages to be processed, the page control unit 304 ends the process.

[0147] <Regarding the processing of Job5> Next, the job control unit 303 starts processing the print job name "Job5" in the print order "5" written in the table 1001. Then, it instructs the PDL analysis unit 305 to write the job attributes specified for the job in the [e] row of the table 1002. Then, it confirms that the automatic adjustment is set to "Yes" in [e][4]. Then, the job control unit 303 instructs the page control unit 304 to start page processing, and in step S1201, the page control unit 304 checks whether there are any pages left to be processed. Thereafter, the process proceeds in steps S1201, S1202, S1203, S1205, S1208, and S1209, but the details have already been explained and will be omitted.

[0148] In step S1209, if there is a patch to be printed in the remaining area, the patch color and priority are read out and recorded in RAM 2203. In this example, "C" is recorded in RAM 2203 in order of highest priority. Then, the process proceeds to step S1210. In step S1210, the patch type determination unit 310 accesses [a][2] in table 1105 and confirms that the number of toner colors used is "2". Then, the number of toner colors used, "2", is subtracted from the number of areas in which patches can be printed, "4", and the fact that the number of remaining areas in which patches of the same color can be printed is "2" is recorded in RAM 2203, and the process proceeds to step S1211.

[0149] In step S1211, the patch type determination unit 310 accesses the RAM 2203 and extracts the toner color that has a priority order and is to be used on the page. In this example, the toner color that has a priority order is "C," and the toner colors to be used on the page are "C" and "M." Therefore, only "C" is designated as the patch color to be printed in multiple locations, and is written to the RAM 2203. Then, the process proceeds to step S1212.

[0150] In step S1212, the patch type determination unit 310 accesses the RAM 2203 to check the toner color to be used, the patch colors to be printed at multiple locations, and their priorities. In the case of this example, the toner colors to be used are "C" and "M", the patch color to be printed at multiple locations is "C", and its priority is "1". When there are two toner colors to be used and patches of only "C" are laid out at multiple locations, "C" and "M" are each laid out at one default location, and the remaining two locations are laid out with patches of "C". That is, the patches of "C" are printed at three locations and the patches of "M" are printed at one location. Since the patches of "M" are printed at one location, the patches with 10 density levels shown in Fig. 8C are used. This patch is marked as "M1" in [a][6] of Table 1105 so that it is printed in area 4 (850) where "M" is defined by default. Also, since the patches of "C" are printed at three locations, the patches with 30 density levels shown in Fig. 8F are used. This patch is specified to be printed in area 1 (810) where "C" is defined by default, area 2 (830) where "Y" and "K" which are not used on this page are specified as default colors, and area 3 (840). Specifically, "C3" is marked in all of [a][3], [a][4], and [a][5] of Table 1105. Then the process proceeds to step S1201. In S1201, if there are no more pages to be processed, the page control unit 304 ends the process.

[0151] <Regarding the processing of Job6> Next, the job control unit 303 starts the processing of the print job name "Job6" with the print order "6" described in Table 1001. Then, it instructs the PDL analysis unit 305 to describe the job attributes specified for the job in row [f] of Table 1002. Then, it checks that it is set to "yes" for automatic adjustment in [f][4]. Then, when the job control unit 303 instructs the page control unit 304 to start page processing, this flow starts.

[0152] In step S1201, the page control unit 304 checks whether any pages remain to be processed. Thereafter, the process proceeds to steps S1201, S1202, S1203, S1205, S1208, and S1209, but the details have already been explained and will not be repeated here. In step S1209, if there is a patch to be printed in the remaining area, the patch color and priority order are read out and recorded in the RAM 2203. In this example, "C" is recorded in the RAM 2203 in descending order of priority. Then, the process proceeds to step S1210.

[0153] In step S1210, the patch type determination unit 310 accesses [a][2] of the table 1106 and confirms that the number of toner colors used is "1". Then, the patch type determination unit 310 subtracts the number of toner colors used "1" from the number of areas "4" where patches can be printed, records in the RAM 2203 that the number of remaining areas where patches of the same color can be printed is "3", and proceeds to step S1211. In step S1211, the patch type determination unit 310 accesses the RAM 2203 and extracts toner colors that have a priority order and are used on the page. In this example, the only toner color that has a priority order is "C", and the only toner color used on the page is "C". Therefore, only "C" is set as the patch color to be printed in multiple places, and is written to the RAM 2203. Then, the process proceeds to step S1212.

[0154] In step S1212, the patch type determination unit 310 accesses the RAM 2203 to check the toner color to be used, the patch colors to be printed at multiple locations, and their priorities. In the case of this example, the toner color to be used is "C", the patch colors to be printed at multiple locations are "C", and the priority is "1". When there is one toner color to be used and only "C" patches are laid out at multiple locations, "C" patches are laid out at the one location defined by default and the remaining three locations. That is, the patch layout is performed so that "C" patches are printed at four locations. Since the "C" patches are printed at four locations, the patches with 40 density levels shown in FIG. 8G are used. This patch is specified to be printed in area 1 (810) where "C" is defined by default, and in the areas where "Y", "K", and "M" which are not used on this page are specified as default colors. That is, "C4" is noted in [a][3], [a][4], [a][5], [a][6] of table 1106 so that it is printed in area 2 (830), area 3 (840), and area 3 (850). Then the process proceeds to step S1201. At S1201, if there are no more pages to be processed, the page control unit 304 ends the process.

[0155] <Regarding the processing of Job7> Next, the job control unit 303 starts the processing of the print job name "Job7" with the print order "7" described in the table 1001. Then, it instructs the PDL analysis unit 305 to describe the job attributes specified for the job in row [g] of the table 1002. Then, it checks that it is set to "yes" for automatic adjustment in [g][4]. Then, when the job control unit 303 instructs the page control unit 304 to start page processing, this flow starts. At step S1201, the page control unit 304 checks whether there are any more pages to be processed. Thereafter, the process proceeds to steps S1201, S1202, S1203, S1205, S1208, S1209, but the details have been described above and are omitted here.

[0156] In step S1209, if there is a patch to be printed in the remaining area, the patch color and priority are read out and recorded in RAM 2203. In this example, "K" is recorded in RAM 2203 in order of highest priority. Then, the process proceeds to step S1210. In step S1210, the patch type determination unit 310 accesses [a][2] in table 1107 and confirms that the number of toner colors used is "1". Then, the number of areas in which patches can be printed, "4", is subtracted by the number of toner colors used, "1", and the number of remaining areas in which patches of the same color can be printed is recorded as "3" in RAM 2203, and the process proceeds to step S1211.

[0157] In step S1211, the patch type determination unit 310 accesses the RAM 2203 and extracts the toner colors that have a priority designation and that are to be used on the page. In this example, the only toner color that has a priority designation is "K," and the only toner color to be used on the page is "K." Therefore, only "K" is designated as the patch color to be printed in multiple locations, and is written to the RAM 2203. Then, the process proceeds to step S1212.

[0158] In step S1212, the patch type determination unit 310 accesses the RAM 2203 and confirms the toner color to be used, the patch color to be printed in multiple locations, and its priority order. In this example, the toner color to be used is "K", the patch color to be printed in multiple locations is "K", and its priority order is "1". When using one color of toner and laying out a patch of only "K" in multiple locations, the "K" patch is laid out in one location where "K" is defined as the default, and the "K" patch is laid out in the remaining three locations. In other words, the patch is laid out so that the "K" patch is printed in four locations. Since the "K" patch is printed in four locations, the patch with 40 levels of density shown in FIG. 8G is used. It is specified that this patch is printed in area 1 (840) where "K" is defined as the default, and in the area where "C", "Y", and "M", which are not used on this page, are specified as default colors. That is, "K4" is entered in [a][3], [a][4], [a][5], and [a][6] in table 1106 so that printing is performed in area 1 (810), area 2 (830), and area 3 (850). Then, the process proceeds to step S1201. In S1201, the page control unit 304 ends the process if there are no pages remaining to be processed.

[0159] As described above, when the patch type is determined in the image processing device 101, the patch type determination unit 310 provided in the image processing device 101 plays a role in this regard.

[0160] <Case where patch is determined by image processing device 103> While the case where the patch type is determined by the image processing device 101 has been described above, when the patch type is determined by the image forming device 103, the patch type determination unit 337 takes over that role. In that case, the information required to determine the patch type is received from the image processing device 101 and the patch type is determined. The method of determining the patch type is the same as that explained in <Case where patch type is determined by the image processing device 101>, so details will be omitted.

[0161] According to this embodiment, the color of the tone patch for tone correction to be combined with the image for each page is determined according to the color components used in the image, and the tone patch of the determined color is combined with the image. The image is then subjected to tone correction based on tone correction information to form an image, the tone patch formed on the medium is colorimetrically measured, and the tone correction information is updated based on the colorimetric value. This allows the tone patches to be combined according to color management information specified by the owner of the print job, and strict color management can be achieved. Furthermore, the remaining tone patch areas can be used to combine tone patches with a larger number of tones, and color management can be stricter.

[0162] <<Second embodiment>> In the first embodiment, a method was described in which the toner colors used in a page are checked from an image obtained by developing a page into a raster image, and adjustment patches are laid out using only the toner colors used on that page. However, some image forming devices do not allow the user to set whether or not to print patches of the four colors of CMYK for each page, or to switch the printing position. In this case, for example, if the color mode is set to "grayscale" in the job settings and "print adjustment marks in the margins of the paper" is set in the automatic adjustment, patches of all colors of CMYK will be placed on the margins of the grayscale image. This makes it impossible to manage the number of colors for each page in the printing system. In this embodiment, a method is described in which a combination of job settings that makes it impossible to manage the number of colors for each page in the printing system is detected and the user is notified of the combination.

[0163] UI constraints table 1301 in FIG. 13(a) is a table for determining whether simultaneous specification of two different job settings is permitted. In this example, column [1] indicates the color mode "CMYK" in the job settings. Column [2] indicates the color mode "grayscale" in the job settings. Row [a] indicates automatic adjustment (real-time correction) in the job settings. Whether or not a combination of settings in each row and column is permitted is recorded. FIG. 13(b) shows an example of a warning screen in which an unauthorized combination of settings has been specified.

[0164] The UI constraints table 1301 and screen 1302 are stored in the ROM 2202, and the CPU 2201 reads them out for use. As already explained in detail in FIG. 9, the user operates the operation unit 2206 to select a job and cause the operation unit 2206 to display the UI 900. The user operates the operation unit 2206 to select grayscale 903 in color mode. Then, when the user specifies "print adjustment marks in the margins of the paper" 910 in automatic adjustment 909 and presses the OK button 919, the CPU 2201 accesses the table 1301 and checks whether the combination of these settings is permitted. In this example, an "X" mark is entered next to the combination of color mode "grayscale" and automatic adjustment in the UI constraints table 1301. The "X" mark indicates that the combination of these settings is "not permitted."

[0165] When the CPU 2201 determines by referring to the UI constraints table 1301 that an unauthorized setting has been made, it acquires a warning screen 1302 from the RAM 2203 and instructs the UI control unit 308 to display it on the operation unit 2206. The user can look at the warning screen 2206 displayed on the operation unit 2206 and select whether to execute printing as is or to cancel in order to redo the job settings.

[0166] 9 is provided in the image processing apparatus 101 and displayed on the operation unit 2206 to allow the user to set the job, but the job can also be set by a utility for setting the job, that is, a so-called print driver. In that case, for example, the print driver operates in the information processing apparatus 102, and it is also possible to set the job and display a warning screen based on the combination of the job settings described in this example.

[0167] According to this embodiment, when using an image forming device that does not allow the user to set whether or not to print each of the four CMYK color patches for each page or to switch the printing position, the user can be warned of the setting to disable color management.

[0168] <<Third embodiment>> Fig. 14 is a flowchart for specifying only the colors specified in the specified color printing as adjustment patches and issuing a print instruction. Each step of the flowchart shown in Fig. 14 is realized by the CPU 2201 reading out a program stored in the ROM 2202. This process is executed by the job control unit 303 when a print job is registered from the print job generation unit 301.

[0169] The job control unit 303 starts this flow when it determines that automatic adjustment is set to "Yes" in the job attribute table 1002. In step S1401, the job control unit 303 accesses the designated color column of the target job in the job attribute table 1002 and refers to the designated color. If there is no designated color, the process ends.

[0170] If there is a specified color, in step S1402, the job control unit 303 notifies the patch type determination unit 310 of the specified color. Upon receiving this notification, the patch type determination unit 310 determines an adjustment patch for the specified color specified in specified color printing and notifies the job control unit 303. Then, starting from the first page of the job, the page control unit 304 is instructed to start processing the pages of interest. In step S1403, the page control unit 304 instructs the RIP control unit 306 to develop a raster image of the page of interest and receives the result. Thereafter, a print instruction is issued, and the procedure may be the same as that after S4010 in FIG. 4A-1.

[0171] <Example> Next, a specific example of the above-mentioned process will be described. In this explanation, "Job3" recorded in row [c] in the job attribute table 1002 in Fig. 10(b) will be used as an example. Note that although the explanation is simplified, it still follows the above-mentioned procedure.

[0172] The job control unit 303 instructs the PDL analysis unit 305 to write the job attributes specified for the print job in row [c] of table 1002. Then, when the job control unit 303 confirms that automatic adjustment "Yes" is set in [c][4], it starts this flow. In step S1401, the job control unit 303 accesses [c][3] in table 1002 to check whether there is a specified color printing specification. If not, the process ends. In this example, [c][3] specifies that printing is to be done in two colors, "C" and "M". In this case, the process proceeds to step S1402.

[0173] In step S1402, the job control unit 303 notifies the patch type determination unit 310 of the designated color printing and the designated color types "C" and "M". Upon receiving this notification, the patch type determination unit 310 designates only "C" and "M" designated in the designated color printing as adjustment patches and notifies the job control unit 303. Then, the process proceeds to step S1403. In step S1403, the job control unit 303 instructs the RIP control unit 306 to perform RIP, and instructs the image generation unit 307 to composite the "C" and "M" patches onto the RIP-posted image and print it, after receiving the result. Then, the patch composition unit 309 composites the images of "C" and "M" onto the RIP-posted image. Then, the process proceeds to step S1404. In step S1404, the patch composition unit 309 transmits a print instruction for the image obtained by combining the patches to the print control data transmission / reception unit 311, and the process ends.

[0174] According to the present embodiment, since the gradation patch of the color designated for each job is synthesized for each page, the process of determining the gradation patch for each page can be omitted. Also, since the gradation patch of the color designated for each job is synthesized for each page, it is possible to avoid unnecessarily expanding the range of colors used, and to perform strict color management.

[0175] [Other Examples] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0176] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0177] 101 Image processing device, 102 Information processing device, 103 Image forming device

Claims

1. a determining means for determining a color of a gradation patch for gradation correction to be combined with an image in accordance with a color component used in the image; a synthesizing means for synthesizing the image with the gradation patch of the determined color to generate an image with the patch; a correction means for performing gradation correction on the patched image based on the gradation correction information for each color component to generate a corrected image; an image forming means for forming the corrected image on a medium; an updating means for measuring the color of the gradation patch formed on the medium and updating the gradation correction information based on the measured color value; having An area in the image into which the gradation patch is to be synthesized is determined in advance; An image forming device characterized in that, when the number of colors determined by the determination means is less than the number of areas, and a setting is made to synthesize the gradation patch in the remainder area, a gradation patch of the color determined by the determination means is synthesized in the remainder area.

2. 2. The image forming apparatus according to claim 1, the image is a page image included in a received print job; The image forming apparatus according to claim 1, wherein the determining unit determines a color to be used on each page as the color of the tone patch.

3. 2. The image forming apparatus according to claim 1, the image is a page image included in a received print job; When a designated color is set in the print job, the determining unit determines the designated color as the color of the tone patch.

4. 4. The image forming apparatus according to claim 1, 2. An image forming apparatus comprising: a color gradation patch to be combined with the remaining area; a number of gradation patches corresponding to the number of the remaining areas;

5. 5. The image forming apparatus according to claim 1, 2. An image forming apparatus according to claim 1, wherein the color of the gradation patch to be combined with the remaining area is determined according to a priority order that is previously specified for each color.

6. 5. The image forming apparatus according to claim 1, An image forming device characterized in that, for a color in which gradation patches are synthesized in multiple said regions, for a gradation patch to be synthesized in one said region, a gradation patch with a number of gradations corresponding to the number of said regions is divided by the number of said regions and synthesized in each region.

7. 7. The image forming apparatus according to claim 1, An image forming device characterized in that, when the number of colors determined by the determination means is less than the number of areas, and if there is no setting to synthesize the gradation patch in the remainder area, the gradation patch is not synthesized in the remainder area.

8. 8. The image forming apparatus according to claim 1, 1. An image forming apparatus, comprising: an image forming unit configured to, when a setting is made to composite tone patches of a predetermined color onto all pages, composite tone patches of the predetermined color onto all pages.

9. 9. The image forming apparatus according to claim 1, the gradation correction information is stored for each type of medium, The image forming apparatus according to claim 1, wherein the correction means performs gradation correction based on the gradation correction information corresponding to the type of the medium.

10. 10. The image forming apparatus according to claim 1, The color components include cyan, magenta, yellow, and black, The image forming apparatus according to claim 1, wherein the determining means determines a color component to be used in the image from among cyan, magenta, yellow, and black as the color of the tone patch.

11. An image forming method using an image forming apparatus having a determining unit, a combining unit, a correcting unit, an image forming unit, and an updating unit, comprising: the determining means determines a color of a gradation patch for gradation correction to be combined with an image in accordance with a color component used in the image; the combining means combines the gradation patch of the determined color with the image to generate an image with the patch; the correction means performs gradation correction on the patched image based on gradation correction information for each color component to generate a corrected image; The image forming means forms the corrected image on a medium; the updating means measures the color of the gradation patch formed on the medium, and updates the gradation correction information based on the measured color value; An area in the image into which the gradation patch is to be synthesized is determined in advance; When the number of colors determined by the determining means is less than the number of the regions, if a setting is made to synthesize the gradation patch in the remaining region, the gradation patch of the color determined by the determining means is synthesized in the remaining region.

1. An image forming method comprising:

Images