Image forming system and printing control program

Abstract

To accurately perform tone correction with high accuracy, as compared with a case of making a screen to be used for a print job and a screen for the tone pattern to be equal to each other, in performing tone correction by reading the tone pattern printed on a recording medium with a reading device.SOLUTION: A print server 10 in performing tone correction by reading a tone pattern printed on a recording medium with a reading device, performs control, for a specific color of the tone pattern, to perform printing using a second screen obtained by changing at least one of the number of screen lines and a screen angle of a first screen used for a print job, and perform printing using a screen adjusted to be equal to the screen used for the print job for colors other than the specific color of the tone pattern.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an image forming system and a print control program. [Background technology]

[0002] For example, Patent Document 1 describes a method for printing a calibration pattern in a printer in which an image is recorded on recording paper, leaving a margin, and at least a part of this margin is cut off with a cutter. In this printing method, a calibration pattern is printed in the margin that will be cut off with the cutter when recording the image. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-239731 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a technology for correcting gradation by reading a gradation pattern printed on a recording medium such as paper using a reading device. Typically, the screen used for the gradation pattern is the same as the screen used for the print job. However, there may be specific colors that cause moiré due to their relationship with the pixel arrangement direction of the image sensor of the reading device or their relationship with the pixel pitch of the image sensor. In this case, if the screen used for the print job is used for the specific color of the gradation pattern, the RGB values ​​of the gradation pattern read by the reading device will vary, making it difficult to perform accurate gradation correction.

[0005] The present disclosure aims to provide an image forming system and a printing control program that can perform gradation correction with greater accuracy when a gradation pattern printed on a recording medium is read by a reading device and gradation correction is performed, compared to when the screen used for the print job and the screen for the gradation pattern are the same. [Means for solving the problem]

[0006] In order to achieve the above object, the image forming system according to the first aspect includes a processor, and when the processor reads a gradation pattern printed on a recording medium using a reading device and performs gradation correction, the processor controls the printing of specific colors of the gradation pattern using a second screen in which at least one of the screen ruling and screen angle of the first screen used in the print job is changed, and the printing of colors other than the specific color of the gradation pattern using the same screen as the screen used in the print job.

[0007] In addition, an image forming system according to a second aspect is the image forming system according to the first aspect, wherein the specific color is black.

[0008] In addition, the image forming system according to the third aspect is the image forming system according to the second aspect, wherein the direction of the primary or secondary component of the first screen is the same as the reading direction of the reading device, and the screen ruling is an integer multiple of the reading resolution of the reading device.

[0009] In addition, an image forming system according to a fourth aspect is the image forming system according to the first aspect, wherein the difference between the screen line number of the second screen and the screen line number of the first screen is 50 lines or less, and the difference between the screen angle of the second screen relative to the reading direction and the screen angle of the first screen relative to the reading direction is 15 degrees or more and 75 degrees or less.

[0010] In addition, an image forming system according to a fifth aspect is the image forming system according to the first aspect, which has pre-stored therein multiple types of screens to be used for the print job, and the second screen is the screen among the multiple types of screens whose screen ruling is closest to the screen ruling of the first screen.

[0011] In addition, an image forming system according to a sixth aspect is the image forming system according to the fifth aspect, wherein the processor performs gradation correction based on the reading results of reading the gradation pattern before or during execution of the print job.

[0012] Furthermore, in order to achieve the above object, the print control program according to the seventh aspect causes a computer to execute a process in which, when a gradation pattern printed on a recording medium is read by a reading device and gradation correction is performed, a specific color of the gradation pattern is printed using a second screen in which at least one of the screen ruling and screen angle of the first screen used in the print job is changed, and colors other than the specific color of the gradation pattern are printed using the same screen as the screen used in the print job. [Effects of the Invention]

[0013] According to the first and seventh aspects, when a gradation pattern printed on a recording medium is read by a reading device and gradation correction is performed, the gradation correction can be performed with greater precision than when the screen used for the print job and the screen for the gradation pattern are the same.

[0014] According to the second aspect, when the specific color is black, the gradation correction can be performed with higher accuracy compared to when the screen used for the print job and the screen for the gradation pattern are the same.

[0015] According to the third aspect, when the screen ruling of the first screen used in the print job is synchronized with the reading resolution of the reading device, gradation correction can be performed with greater precision than when the first screen and the screen of the gradation pattern are the same.

[0016] According to the fourth aspect, there is an effect that it is possible to define the difference in screen ruling and the difference in screen angle in order to perform tone correction with higher accuracy.

[0017] According to the fifth aspect, there is an effect that tone correction can be performed with high accuracy using an existing screen without implementing a screen dedicated to a specific color.

[0018] According to the sixth aspect, there is an effect that tone correction can be performed before or during execution of a print job. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of an image forming system according to a first embodiment. [Figure 2] FIG. 10 is a diagram showing an example of a recording medium on which a gradation pattern is printed. [Figure 3] FIG. 2 is a block diagram showing an example of the electrical configuration of the print server according to the first embodiment. [Figure 4] FIG. 2 is a block diagram showing an example of the electrical configuration of the printing apparatus according to the first embodiment. [Figure 5] FIG. 2 is a diagram showing a state in which the reading device according to the embodiment is seen from the side; [Figure 6] FIG. 1 is a diagram illustrating an example of a screen. [Figure 7] FIG. 2 is a block diagram illustrating an example of a functional configuration of a print server according to the embodiment. [Figure 8] 10A and 10B are diagrams illustrating an embodiment in which a K-color screen is changed on a recording medium. [Figure 9] 6 is a flowchart showing an example of a processing flow by a print control program according to the first embodiment. [Figure 10] 10 is a flowchart showing an example of a processing flow by a print control program according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] An example of an embodiment of the technology of the present disclosure will be described in detail below with reference to the drawings. Note that components and processes that perform similar operations, actions, and functions are given the same reference numerals throughout the drawings, and duplicated descriptions may be omitted as appropriate. Each drawing is merely a schematic illustration to allow a sufficient understanding of the technology of the present disclosure. Therefore, the technology of the present disclosure is not limited to the illustrated examples. Furthermore, in this embodiment, descriptions of configurations that are not directly related to the technology of the present disclosure or well-known configurations may be omitted.

[0021] [First embodiment] FIG. 1 is a diagram showing an example of the configuration of an image forming system 100 according to the first embodiment.

[0022] As shown in FIG. 1, the image forming system 100 according to this embodiment includes a print server 10, a printing device 20, and a reading device 40.

[0023] The print server 10 is connected to the printing device 20 via a network N. The network N may be the Internet, a local area network (LAN), a wide area network (WAN), or the like. There are no restrictions on the connection form of the network N, and it may be wired, wireless, or a combination of wired and wireless. The print server 10 performs various settings for the printing device 20, sends print jobs to the printing device 20, and controls the printing operation of the printing device 20.

[0024] The printing device 20 is a device that executes printing processing in accordance with a print job from the print server 10. Specifically, the printing device 20 has a printing function that prints an image represented by image data included in the print job onto a recording medium such as paper.

[0025] The reading device 40 is connected downstream of the printing device 20 and has the function of reading a recording medium on which an image is printed by the printing device 20. Specifically, the image forming system 100 has the function of reading a gradation pattern printed on a recording medium during execution of a print job with the reading device 40 and correcting the gradation (hereinafter referred to as an "in-job correction function"). However, the in-job correction function can also be performed before execution of a print job.

[0026] 2 is a diagram showing an example of a recording medium P on which a gradation pattern is printed. The recording medium P is, for example, an A3-sized sheet of paper, and includes a printing area R1 in which the image data that the user wants to print is printed, and a margin area R2 in which the gradation pattern Kp and alignment register marks At are printed. The margin area R2 is an area that is cut after printing.

[0027] The gradation patterns Kp and alignment marks At are read by the reading device 40, and density variations and front-to-back misalignment are detected during execution of a print job. The gradation patterns Kp are multiple types of patterns for detecting density variations, and the in-job correction function compares the gradation pattern Kp of the first page with the gradation patterns Kp of subsequent pages and feeds back a gradation correction value based on the comparison result to the printing device 20. For example, the densities of the gradation patterns of yellow (Y), magenta (M), cyan (C), and black (K) are measured, and a correction value is calculated to eliminate deviations from a reference value (e.g., the density of the gradation pattern Kp of the first page). Based on this correction value, the gradation characteristics of the printing device 20 are controlled to achieve the reference density.

[0028] The "register marks" referred to here are used as a guide when aligning the front and back of the recording medium P. The alignment register marks At are marks for detecting misalignment between the front and back, and the in-job correction function compares the alignment register marks At of the first page with the alignment register marks At of subsequent pages, and feeds back to the printing device 20 a correction value based on the comparison result.

[0029] FIG. 3 is a block diagram showing an example of the electrical configuration of the print server 10 according to the first embodiment.

[0030] As shown in FIG. 3, the print server 10 according to this embodiment includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, an input / output interface (I / O) 14, a storage unit 15, a display unit 16, an operation unit 17, and a communication unit 18.

[0031] The CPU 11, ROM 12, RAM 13, and I / O 14 are connected to each other via a bus. Functional units including a storage unit 15, a display unit 16, an operation unit 17, and a communication unit 18 are connected to the I / O 14. These functional units can communicate with the CPU 11 via the I / O 14.

[0032] The control unit is composed of the CPU 11, ROM 12, RAM 13, and I / O 14. The control unit may be configured as a sub-control unit that controls part of the operation of the print server 10, or may be configured as part of the main control unit that controls the overall operation of the print server 10. For example, an integrated circuit such as an LSI (Large Scale Integration) or an IC (Integrated Circuit) chip set is used for part or all of the blocks of the control unit. Individual circuits may be used for each of the above blocks, or a circuit in which part or all of the blocks are integrated may be used. The above blocks may be provided integrally, or some of the blocks may be provided separately. Furthermore, part of each of the above blocks may be provided separately. The integration of the control unit is not limited to LSI, and a dedicated circuit or a general-purpose processor may also be used.

[0033] For example, a hard disk drive (HDD), a solid state drive (SSD), or a flash memory may be used as the storage unit 15. A print control program 15A according to this embodiment is stored in the storage unit 15. Note that the print control program 15A may be stored in the ROM 12.

[0034] The print control program 15A may be pre-installed in the print server 10, for example. The print control program 15A may be realized by storing it in a non-volatile storage medium or distributing it via the network N and installing it appropriately in the print server 10. Examples of non-volatile storage media include a CD-ROM (Compact Disc Read Only Memory), a magneto-optical disk, a HDD, a DVD-ROM (Digital Versatile Disc Read Only Memory), a flash memory, a memory card, etc.

[0035] The display unit 16 may be, for example, a liquid crystal display (LCD) or an organic electroluminescence (EL) display. The display unit 16 may be integrated with a touch panel. The operation unit 17 is provided with operation input devices such as a keyboard and a mouse. The display unit 16 and the operation unit 17 accept various instructions from a user of the print server 10. The display unit 16 displays various information such as the results of processing executed in response to instructions accepted from the user and notifications regarding the processing.

[0036] The communication unit 18 is connected to a network N such as the Internet, a LAN, or a WAN, for example, and is capable of communicating with the printing device 20 via the network N.

[0037] FIG. 4 is a block diagram showing an example of the electrical configuration of the printing device 20 according to the first embodiment.

[0038] As shown in FIG. 4, the printing device 20 according to this embodiment includes a CPU 21, a ROM 22, a RAM 23, an I / O 24, a memory unit 25, a display unit 26, an operation unit 27, a printing unit 28, a communication unit 29, and a connection unit 30.

[0039] The CPU 21, ROM 22, RAM 23, and I / O 24 are connected to each other via a bus. Functional units including a storage unit 25, a display unit 26, an operation unit 27, a printing unit 28, a communication unit 29, and a connection unit 30 are connected to the I / O 24. These functional units can communicate with the CPU 21 via the I / O 24.

[0040] The control unit is made up of the CPU 21, ROM 22, RAM 23, and I / O 24. The control unit may be configured as a sub-control unit that controls part of the operation of the printing device 20, or may be configured as part of a main control unit that controls the overall operation of the printing device 20.

[0041] For example, an HDD, an SSD, a flash memory, etc., is used as the storage unit 25. A program required to execute the printing process is stored in the storage unit 25. Note that this program may be stored in the ROM 22.

[0042] The display unit 26 may be, for example, a liquid crystal display (LCD), an organic EL display, or the like. The display unit 26 may be integrated with a touch panel. The operation unit 27 is provided with various operation keys, such as a numeric keypad and a start key. The display unit 26 and the operation unit 27 act as an operation panel and receive instructions regarding the various functions and settings of the printing device 20.

[0043] The printing unit 28 forms an image on paper, which is an example of a recording medium, based on image data obtained by a print instruction from the print server 10. Note that, although the following description will be given using an electrophotographic method as an example of a method for forming an image, other methods such as an inkjet method may also be used.

[0044] When the image formation method is electrophotography, the printing unit 28 includes a photosensitive drum, a charging device, an exposure device, a developing device, a transfer device, and a fixing device. The charging device applies a voltage to the photosensitive drum to charge the surface of the photosensitive drum. The exposure device forms an electrostatic latent image on the photosensitive drum by exposing the photosensitive drum, which has been charged by the charging device, to light according to image data. The developing device develops the electrostatic latent image formed on the photosensitive drum with toner to form a toner image on the photosensitive drum. The transfer device transfers the toner image formed on the photosensitive drum to paper. The fixing device fixes the toner image transferred to the paper by applying heat and pressure.

[0045] The communication unit 29 is a communication interface for connecting to a network N such as the Internet, a LAN, or a WAN, and enables communication with the print server 10 via the network N. The connection unit 30 is an interface for connecting to a reading device 40. The reading device 40 is connected to the rear stage of the printing device 20, and the recording medium P printed by the printing device 20 is transported to the reading device 40.

[0046] 5 is a side view of the reading device 40 according to this embodiment. The reading device 40 includes multiple pairs of transport rolls 41 that transport the recording medium P, and multiple reading units 42 that read the gradation pattern Kp of the recording medium P.

[0047] 5 shows four pairs of transport rolls 41, but this is not limited to four pairs, and any number of transport rolls may be provided depending on the performance required for the reading device 40. The reading unit 42 on the upstream side in the transport direction reads the gradation pattern Kp on the front side of the recording medium P, and the reading unit 42 on the downstream side in the transport direction reads the gradation pattern Kp on the back side of the recording medium P. The reading resolution of the reading device 40 may be fixed or variable.

[0048] Figure 6 is a diagram showing an example of a screen. In Figure 6, the white squares represent pixels in print resolution units (for example, 2400 dpi), and the black areas represent screen dots. Screening (halftone dots) is a technology that creates printed and non-printed areas to express the shades of an image. Creating printed and non-printed areas separately in print resolution units would result in a decrease in print quality, so a single screen dot is formed with a certain size (period).

[0049] A screen includes a primary component and a secondary component. The primary component direction is tilted 45 degrees from the horizontal. The primary component is expressed, for example, as 212 lines, 45 degrees. The secondary component direction is along the horizontal direction. The secondary component is expressed, for example, as 300 lines, 0 degrees. "Screen ruling" is a measure of printing precision, and indicates the fineness of the halftone dots (how many halftone dots fit in 1 inch = 25.4 mm), and is expressed in units of lpi (lines per inch). "Screen angle" indicates the angle of the screen lines or output halftone dots relative to a horizontal or vertical line.

[0050] The printing device 20 expresses, for example, four colors, YMCK, but if the screen rulings and screen angles of the four colors are close to each other, moire patterns may occur. For this reason, different screen angles are generally used for YMCK. For example, a 45-degree screen, which is suitable for drawing characters and lines, is assigned to the K color, and other angles are assigned to the Y, M, and C colors. The Y, M, and C colors are often separated by 15 degrees or more to prevent long-period moire patterns.

[0051] Here, the screen used for the gradation pattern Kp is the same as the screen used for the print job, as described above, but there may be specific colors that cause moiré due to their relationship with the arrangement direction of pixels in the reading unit 42 (image sensor) of the reading device 40 or their relationship with the pixel pitch of the reading unit 42 (image sensor). In this case, if the screen used for the print job is used for the specific color of the gradation pattern Kp, the RGB values ​​of the gradation pattern Kp read by the reading device 40 will vary, making it difficult to perform gradation correction with high accuracy.

[0052] Therefore, in the image forming system 100 according to this embodiment, when the reading device 40 reads the gradation pattern Kp printed on the recording medium P and performs gradation correction, the specific color of the gradation pattern Kp is printed using a second screen in which at least one of the screen ruling and screen angle of the first screen used in the print job is changed, and the colors other than the specific color of the gradation pattern Kp are printed using the same screen as the screen used in the print job.

[0053] Specifically, the CPU 11 of the print server 10 according to this embodiment writes the print control program 15A stored in the storage unit 15 or the ROM 12 into the RAM 13 and executes it, thereby functioning as each unit shown in Fig. 7. The CPU 11 is an example of a processor.

[0054] FIG. 7 is a block diagram showing an example of the functional configuration of the print server 10 according to this embodiment.

[0055] As shown in FIG. 7, the CPU 11 of the print server 10 according to this embodiment functions as an acquisition unit 11A, a correction setting unit 11B, and a print control unit 11C.

[0056] The acquisition unit 11A acquires image data that the user wants to print and acquires printing conditions related to the image data. The acquisition unit 11A accepts the image data and printing conditions via, for example, a print setting screen (not shown). The printing conditions include, for example, the paper type (size, basis weight, etc.) of the recording medium P, the conveyance direction of the recording medium P, etc.

[0057] The correction setting unit 11B sets the in-job correction function. When this setting is made, the in-job correction function is enabled. The correction setting unit 11B accepts the setting of the in-job correction function via, for example, a function setting screen (not shown).

[0058] When the in-job correction function is enabled, the print control unit 11C controls the printing of a specific color of the gradation pattern Kp using a second screen obtained by changing at least one of the screen ruling and screen angle of the first screen used in the print job, and the printing of colors other than the specific color of the gradation pattern Kp using the same screen as the screen used in the print job. Specifically, the specific color is, for example, black (K). For example, the direction of the primary or secondary component of the first screen is the same as the reading direction of the reading device 40, and the screen ruling is an integer multiple of the reading resolution of the reading device 40. If the secondary component of the screen is, for example, 300 lines / 0 degrees and the reading resolution is, for example, 300 dpi, the screen ruling is an integer multiple of the reading resolution of the reading device 40, i.e., a synchronous relationship, and long-period moire may occur.

[0059] Among the screens installed in the printing device 20, the first screen that is an integral multiple of the reading resolution of the reading device 40 is known in advance, and therefore a second screen different from this first screen is installed in the printing device 20 in advance. The second screen is stored in the ROM 22 or the storage unit 25 as a screen dedicated to a specific color in order to suppress variations in the read gradation. The second screen may differ from the first screen only in the screen ruling, or may differ from the first screen only in the screen angle. Alternatively, the second screen may differ from the first screen in both the screen ruling and the screen angle.

[0060] More specifically, for example, it is desirable that the difference between the screen ruling of the second screen and the screen ruling of the first screen be 50 lines or less, and that the difference between the screen angle of the second screen relative to the reading direction and the screen angle of the first screen relative to the reading direction be 15 degrees or more and 75 degrees or less. More desirably, the difference between the screen ruling of the second screen and the screen ruling of the first screen be 30 lines or less.

[0061] Furthermore, for colors other than the specific color of the gradation pattern Kp (for example, K), for example, C, M, and Y, control is performed to print using the same screen as that used for the print job. Here, the screen angles for C, M, and Y may be different.

[0062] The print control unit 11C controls the gradation characteristics of the output from the printing device 20 based on the image data of the gradation pattern Kp printed on the recording medium P together with the job image data. Note that the job image data is image data corresponding to the user's print job. Specifically, the print control unit 11C controls the gradation characteristics of the output from the printing device 20, for example, while the print job is being executed.

[0063] Next, with reference to FIG. 8, a specific description will be given of an embodiment for changing the K color screen on the recording medium P.

[0064] 8 is a diagram illustrating an embodiment in which the K-color screen is changed on the recording medium P. Position W1 is a position where the first gradation pattern Kp1 is printed, and position W2 is a position where the second gradation pattern Kp2 is printed.

[0065] The first gradation pattern Kp1 is preset with a first screen to be used for the print job. The first gradation pattern Kp1 is, for example, a gradation pattern for the color K. In this case, the first screen used for the first gradation pattern Kp1 is changed to the second screen. As described above, the second screen and the first screen differ in at least one of the screen ruling and the screen angle.

[0066] On the other hand, the screen used for the print job is set in advance for the second gradation pattern Kp2. The second gradation pattern Kp2 is, for example, a gradation pattern of one of the colors C, M, and Y. However, as described above, the screen angle may be different for each of the colors C, M, and Y. The screen used for the second gradation pattern Kp2 is the same as the screen used for the print job.

[0067] Next, the operation of the print server 10 according to the first embodiment will be described with reference to FIG.

[0068] FIG. 9 is a flowchart showing an example of the processing flow of the print control program 15A according to the first embodiment.

[0069] First, the print control program 15A is started by the CPU 11 of the print server 10, and the following steps are executed.

[0070] 9, the CPU 11 acquires the image data that the user wants to print and the printing conditions related to the image data. As described above, the printing conditions include, for example, the paper type (size, basis weight, etc.) of the recording medium P, the conveyance direction of the recording medium P, etc.

[0071] In step S102, the CPU 11 determines whether the in-job correction function is enabled. If it is determined that the in-job correction function is enabled (in the case of a positive determination), the process proceeds to step S103, and if it is determined that the in-job correction function is not enabled (in the case of a negative determination), the process proceeds to step S105.

[0072] In step S103, CPU 11 determines whether or not the gradation pattern Kp is K. If it is determined that the gradation pattern Kp is K (if the determination is positive), the process proceeds to step S104, and if it is determined that the gradation pattern Kp is not K (if the determination is negative), the process proceeds to step S105.

[0073] In step S104, CPU 11 changes the first screen used for the print job to a second screen dedicated to the color K. As described above, the second screen is a screen that differs from the first screen in at least one of the screen ruling and screen angle.

[0074] In step S105, the CPU 11 outputs a print job including image data and control data to the printing device 20, and ends a series of processes according to the print control program 15A.

[0075] In this way, according to this embodiment, for a specific color of a gradation pattern, the first screen used in the print job is changed to a second screen dedicated to the specific color, thereby suppressing variations in the read gradation and enabling accurate gradation correction.

[0076] In this embodiment, an example has been described in which it is determined whether the gradation pattern is K color or not and whether to change the screen of the gradation pattern is controlled, but it is also possible to link the K color of the gradation pattern and the screen of the gradation pattern in advance without going through this determination process and control the change of the screen of the gradation pattern for the K color of the gradation pattern.

[0077] [Second embodiment] In the first embodiment, a configuration in which a second screen dedicated to a specific color is pre-installed to suppress variations in read gradation is described. In the second embodiment, a configuration in which a second screen is selected and used from multiple types of screens used for a print job is described.

[0078] As in the first embodiment, it is desirable to implement a second screen dedicated to a specific color in advance to suppress variations in the read gradation. However, since a large amount of storage capacity is required to store the screen data, this may be difficult to implement in advance depending on the printing device 20. For this reason, the second screen may be selected and used from among multiple types of screens used in the print job. The multiple types of screens referred to here are existing screens used in the print job and are stored in advance in the printing device 20. The second screen is, for example, the screen of the multiple types of screens used in the print job whose screen ruling is closest to the screen ruling of the first screen.

[0079] Next, the operation of the print server 10 according to the second embodiment will be described with reference to FIG.

[0080] FIG. 10 is a flowchart showing an example of the processing flow of the print control program 15A according to the second embodiment.

[0081] First, the print control program 15A is started by the CPU 11 of the print server 10, and the following steps are executed.

[0082] 10, the CPU 11 acquires the image data that the user wants to print and the printing conditions related to the image data. As described above, the printing conditions include, for example, the paper type (size, basis weight, etc.) of the recording medium P, the conveyance direction of the recording medium P, etc.

[0083] In step S112, the CPU 11 determines whether the in-job correction function is enabled. If it is determined that the in-job correction function is enabled (in the case of a positive determination), the process proceeds to step S113, and if it is determined that the in-job correction function is not enabled (in the case of a negative determination), the process proceeds to step S115.

[0084] In step S113, CPU 11 determines whether or not the gradation pattern Kp is K. If it is determined that the gradation pattern Kp is K (if the determination is positive), the process proceeds to step S114, and if it is determined that the gradation pattern Kp is not K (if the determination is negative), the process proceeds to step S115.

[0085] In step S114, CPU 11 changes the first screen used for the print job to a different second screen. As described above, the second screen is the screen with the screen ruling closest to that of the first screen among the multiple types of screens used for the print job. The second screen is selected from the existing screens stored in advance in printing device 20 and used.

[0086] In step S115, the CPU 11 outputs a print job including image data and control data to the printing device 20, and ends a series of processes according to the print control program 15A.

[0087] According to this embodiment, the second screen used for a specific color of the gradation pattern is selected from among the multiple screens used for the print job, which reduces the variation in the read gradation while minimizing the increase in storage capacity, enabling accurate gradation correction.

[0088] In this embodiment, an example has been described in which it is determined whether the gradation pattern is K color or not and whether to change the screen of the gradation pattern is controlled, but it is also possible to link the K color of the gradation pattern and the screen of the gradation pattern in advance without going through this determination process and control the change of the screen of the gradation pattern for the K color of the gradation pattern.

[0089] In the above embodiments, the print server 10 has been described as the controlling entity, but the printing device 20 may also be the controlling entity. When the printing device 20 is the controlling entity, the printing control program according to this embodiment may be stored in the storage unit 25 or ROM 22 of the printing device 20, and the printing control program may be read and executed by the CPU 21.

[0090] In each of the above embodiments, the term "processor" refers to a processor in a broad sense, and includes general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.).

[0091] Furthermore, the operations of the processor in each of the above embodiments may not only be performed by a single processor, but may also be performed by multiple processors located at physically separate locations working together. Furthermore, the order of the operations of the processor is not limited to the order described in each of the above embodiments, and may be changed as appropriate.

[0092] The image forming system according to the embodiment has been described above as an example. The embodiment may be in the form of a program for causing a computer to execute the functions of each unit of the image forming system. The embodiment may be in the form of a non-transitory storage medium that stores the program and is readable by a computer.

[0093] Furthermore, the configuration of the image forming system described in the above embodiment is merely an example, and may be changed depending on the situation without departing from the spirit of the invention.

[0094] Furthermore, the processing flow of the program described in the above embodiment is also an example, and unnecessary steps may be deleted, new steps may be added, or the processing order may be rearranged within the scope of the main idea.

[0095] In the above embodiment, the processing according to the embodiment is realized by a software configuration using a computer by executing a program, but the present invention is not limited to this. The embodiment may be realized by, for example, a hardware configuration or a combination of a hardware configuration and a software configuration.

[0096] The following additional notes are provided regarding the above-described embodiments.

[0097] (Addendum) (((1))) a processor; The processor: When a gradation pattern printed on a recording medium is read by a reading device and gradation correction is performed, a specific color of the gradation pattern is printed using a second screen obtained by changing at least one of the screen ruling and the screen angle of a first screen used in the print job; and performing control to print colors other than the specific color of the gradation pattern using the same screen as that used for the print job. Imaging system. (((2))) The specific color is black. The image forming system according to (((1))). (((3))) the first screen has a direction of a main component or a subcomponent that is the same as the reading direction of the reading device, and a screen ruling that is an integer multiple of the reading resolution of the reading device; The image forming system according to (((1))) or (((2))). (((4))) a difference between the screen ruling of the second screen and the screen ruling of the first screen is 50 lines or less, and a difference between the screen angle of the second screen with respect to the reading direction and the screen angle of the first screen with respect to the reading direction is 15 degrees or more and 75 degrees or less; The image forming system according to (((3))). (((5))) a plurality of types of screens to be used for the print job are stored in advance; the second screen is a screen among the plurality of types of screens whose screen ruling is closest to that of the first screen; The image forming system according to any one of (((1))) to (((4))). (((6))) the processor performs gradation correction based on a reading result of reading the gradation pattern before or during execution of the print job; The image forming system according to any one of (((1))) to (((5))). (((7))) When a gradation pattern printed on a recording medium is read by a reading device and gradation correction is performed, a specific color of the gradation pattern is printed using a second screen obtained by changing at least one of the screen ruling and the screen angle of a first screen used in the print job; and performing control to print colors other than the specific color of the gradation pattern using the same screen as that used for the print job. A printing control program that causes a computer to execute the process.

[0098] According to (((1))) and (((7))), when a gradation pattern printed on a recording medium is read by a reading device and gradation correction is performed, the gradation correction can be performed with higher accuracy than when the screen used for the print job and the screen for the gradation pattern are the same. According to (((2))), when the specific color is black, the gradation correction can be performed with higher accuracy compared to when the screen used for the print job and the screen for the gradation pattern are the same. According to (((3))), when the screen ruling of the first screen used in the print job is synchronized with the reading resolution of the reading device, gradation correction can be performed with higher accuracy than when the first screen and the screen of the gradation pattern are the same. According to (((4))), there is an effect that it is possible to define the difference in screen ruling and the difference in screen angle in order to perform gradation correction with higher accuracy. According to (((5))), there is an effect that tone correction can be performed with high accuracy using an existing screen without implementing a screen dedicated to a specific color. According to (((6))), there is an effect that tone correction can be performed before or during execution of a print job. [Explanation of symbols]

[0099] 10 Print Server 11 CPU 11A Acquisition Department 11B Function setting section 11C Printing control unit 12 ROM 13 RAM 14 I / O 15 Storage section 15A Printing control program 16 Display section 17 Control section 18 Communications Department 20 Printing device 40 Reading device 100 Image forming system

Claims

1. a processor; The processor: When a gradation pattern printed on a recording medium is read by a reading device and gradation correction is performed, a specific color of the gradation pattern is printed using a second screen obtained by changing at least one of the screen ruling and the screen angle of a first screen used in the print job; and performing control to print colors other than the specific color of the gradation pattern using the same screen as that used for the print job. Imaging system.

2. The specific color is black. The image forming system according to claim 1 .

3. the first screen has a direction of a main component or a subcomponent that is the same as the reading direction of the reading device, and a screen ruling that is an integer multiple of the reading resolution of the reading device; The image forming system according to claim 1 .

4. a difference between the screen ruling of the second screen and the screen ruling of the first screen is 50 lines or less, and a difference between the screen angle of the second screen with respect to the reading direction and the screen angle of the first screen with respect to the reading direction is 15 degrees or more and 75 degrees or less; The image forming system according to claim 3 .

5. a plurality of types of screens to be used for the print job are stored in advance; the second screen is a screen among the plurality of types of screens that has a screen ruling closest to the screen ruling of the first screen; The image forming system according to claim 1 .

6. the processor performs gradation correction based on a reading result of reading the gradation pattern before or during execution of the print job; The image forming system according to claim 1 .

7. When a gradation pattern printed on a recording medium is read by a reading device and gradation correction is performed, a specific color of the gradation pattern is printed using a second screen obtained by changing at least one of the screen ruling and the screen angle of a first screen used in the print job; and performing control to print colors other than the specific color of the gradation pattern using the same screen as that used for the print job. A printing control program that causes a computer to execute the process.

Images