Image inspection device, image forming system, and program

Abstract

To provide an image inspection device, an image formation system, and a program that are improved in image inspection accuracy.SOLUTION: An image inspection device comprises: a first color conversion processing part which applies color conversion to input image data inputted to a print engine, on the basis of a first color conversion table created according to first patch data acquired at the time of initial setting of the print engine, to generate a first basic image; and a second color conversion processing part which applies color conversion to the first basic image, on the basis of a second color conversion table acquired at a printing condition or / and timing different from those at the acquisition time of the first patch data, to generate a second basic image.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This invention relates to an image inspection apparatus, an image forming system, and a program. [Background technology]

[0002] Conventionally, inkjet recording devices have been used to form images by ejecting ink droplets from an inkjet head onto a transported recording medium. In inkjet recording devices, image defects such as streaks and smudges occur in the formed image due to the adhesion of foreign matter to the fine nozzles that serve as the ink ejection ports of the inkjet head, residual ink, and the presence of air bubbles. Methods for inspecting these image defects include comparing scanned images with each other, or comparing a reference image data with scanned inspection image data.

[0003] Patent Document 1 discloses an image inspection device that performs image inspection by comparing scanned inspection image data with reference image data, and includes a configuration for correcting the reference image data according to the type of paper. In Patent Document 1, the reference image data in CMYK format is converted to image data in the same RGB or Lab color space as the inspection image based on correction parameters that include paper attribute information. This improves the accuracy of the reference image data. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2012-137481 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Incidentally, the output image is affected not only by the type of paper, but also by changes in the machine over time, machine differences between individual machines, and print settings. On the other hand, the technology described in Patent Document 1 does not take into account changes in the machine over time, machine differences, print settings, etc. Therefore, there is a challenge in image inspection equipment to perform image inspection with high accuracy by taking into account the effects of changes in the machine over time, machine differences, print settings, etc., in addition to the type of paper.

[0006] Therefore, the present invention aims to provide an image inspection apparatus, an image forming system, and a program that improve the accuracy of image inspection. [Means for solving the problem]

[0007] To solve the above problems and achieve the objectives of the present invention, the image inspection apparatus of the present invention has a first color conversion processing unit that converts the input image data input to the print engine based on a first color conversion table and generates a first basic image. It also has a second color conversion processing unit that converts the first basic image based on a second color conversion table and generates a second basic image. Furthermore, it includes an inspection processing unit that performs image inspection by comparing the second basic image with an inspection image obtained by reading the image on the recording medium output from the print engine with an image reading sensor. The first color conversion table is generated based on first patch data acquired in advance. The second color conversion table is generated based on second patch data acquired under different printing conditions and / or timings than when the first patch data was acquired.

[0008] Furthermore, the image forming system of the present invention comprises a print engine for printing an image onto a recording medium, and the above-mentioned image inspection device for inspecting the image output from the print engine.

[0009] Further, the program of the present invention has a step of color-converting input image data input to a print engine based on a first color conversion table generated based on first patch data acquired in advance, and generating a first basic image. Further, it has a step of color-converting the first basic image based on a second color conversion table acquired under printing conditions or / and timing different from those at the time of acquiring the first patch data, and generating a second basic image. It has a step of performing image inspection by comparing the second basic image with an inspection image obtained by reading an image on a recording medium output from the print engine with an image reading sensor.

Effect of the Invention

[0010] According to the present invention, in an image inspection apparatus, the accuracy of image inspection can be improved.

Brief Description of the Drawings

[0011] [Figure 1] It is an overall configuration diagram of an image forming system 1 according to an embodiment of the present invention. [Figure 2] It is a block diagram showing a control system of an image forming system 1 according to an embodiment of the present invention. [Figure 3] It is a flowchart showing a method for generating a first color conversion table. [Figure 4] It is a diagram showing a control block used for generating the first color conversion table. <0000??7> [Figure 5] It is a diagram showing a first color conversion table generated by a first color conversion table generation unit??2. <00??00>It is a flowchart showing a method for generating a second color conversion table implemented during execution of a print job. [Figure 7] It is a diagram showing a control block used for generating the second color conversion table. [Figure 8] It is an example of a second color conversion table generated in step S14. [Figure 9] It is a flowchart showing an image inspection method in an image inspection apparatus 50 according to an embodiment of the present invention. [Figure 10] This is a diagram showing a control block used during image inspection.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, an example of an image forming system including an image inspection apparatus according to an embodiment of the present invention and a program related to an image inspection method will be described with reference to the drawings. Note that the present invention is not limited to the following examples. In each of the figures described below, common members are denoted by the same reference numerals. The description will be made in the following order. 1. Overall Configuration of the Image Forming System 2. Control Configuration of the Image Forming System 3. Image Inspection Method

[0013] 1. Overall Configuration of the Image Forming System FIG. 1 is an overall configuration diagram of an image forming system 1 according to an embodiment of the present invention (hereinafter, this embodiment). As shown in FIG. 1, the image forming system 1 of this embodiment includes a print controller (hereinafter, DFE (Digital Front End)) 10, an image forming apparatus 70, a colorimeter 60, and an image inspection apparatus 50.

[0014] [DFE] Based on a print job transmitted from an external device such as a client PC (not shown), the DFE 10 performs RIP (Raster Image Process) processing on the image data included in the print job and generates bitmap format image data composed of CMYK (Cyan, Magenta, Yellow, Black). The image data is transmitted to the image forming apparatus 70. The DFE 10 is configured by an information processing apparatus such as a PC or a server, for example.

[0015] [Image Forming Apparatus] The image forming apparatus 70 is a device that forms and prints an image on a recording medium such as paper based on image data transmitted from the DFE 10, and in this embodiment, an inkjet recording device is shown as an example. The image forming apparatus 70 has a paper feeding unit 20, an image forming unit 30, and a paper discharge unit 40.

[0016] The image forming apparatus 70, under the control of a control unit (not shown), transports the recording medium stored in the paper feeding unit 20 to the image forming unit 30, forms an image on the recording medium in the image forming unit 30, and discharges the recording medium with the image formed on it to the paper discharge unit 40.

[0017] The paper feeding unit 20 includes a paper feeding tray for storing recording media made of, for example, paper, and a transport unit for transporting the recording media from the paper feeding tray to the image forming unit 30.

[0018] The image forming unit 30 includes, for example, a print engine 35 composed of an image forming drum 31, a head unit 32, and an irradiation unit 33, and an image reading sensor 34.

[0019] The image forming drum 31 is composed of a cylindrical member and rotates counterclockwise by a drive motor (not shown). The image forming drum 31 carries a recording medium along its cylindrical outer surface and transports the recording medium as it rotates. The transport surface of the image forming drum 31 faces the head unit 32 and the irradiation unit 33, and the head unit 32 and the irradiation unit 33 perform image forming processing on the recording medium transported by the image forming drum 31.

[0020] The head unit 32 is provided with a length (width) that covers the entire recording medium in the direction perpendicular to the transport direction of the recording medium (the width direction of the recording medium). In other words, the image forming apparatus 70 is a one-pass line head type inkjet recording apparatus. The head unit 32 can be configured as a line head by arranging multiple inkjet heads.

[0021] Furthermore, the head unit 32 is provided individually for each color (CMYK) used in image formation. In the image forming apparatus 70 shown in Figure 1, the head units 32 corresponding to each color are provided in the order of Y, M, C, and K from upstream, along the transport direction of the recording medium that is transported as the image forming drum 31 rotates.

[0022] The ink used in the image forming apparatus 70 in this embodiment is, for example, an ultraviolet (UV) curing ink. When not irradiated with UV light, this UV curing ink undergoes a phase change between a gel state and a liquid (sol) state depending on the temperature. This ink has a phase change temperature of, for example, 40°C to 100°C, and uniformly liquefies (becomes a sol) when heated above this phase change temperature. On the other hand, this ink gels at a predetermined temperature, including around normal room temperature (0°C to 30°C).

[0023] The irradiation unit 33 irradiates the image forming apparatus 70 of this embodiment with energy rays to cure the ink after it has been ejected onto the recording medium. The irradiation unit 33 has, for example, a fluorescent tube such as a low-pressure mercury lamp, and emits light from the fluorescent tube to irradiate with energy rays such as ultraviolet rays. The irradiation unit 33 is located near the outer circumferential surface of the image forming drum 31 and is provided downstream of the head unit 32 in the direction of transport of the recording medium by the rotation of the image forming drum 31. The irradiation unit 33 irradiates the recording medium, which is supported on the image forming drum 31 and from which the ink has been ejected, with energy rays to cure the ink ejected onto the recording medium by the action of the energy rays.

[0024] Examples of fluorescent tubes that emit ultraviolet light include low-pressure mercury lamps, mercury lamps with operating pressures of several hundred Pa to 1 MPa, light sources that can be used as germicidal lamps, cold cathode tubes, ultraviolet laser light sources, metal halide lamps, and light-emitting diodes. Among these, light sources that can irradiate ultraviolet light at a higher intensity and consume less power (e.g., light-emitting diodes) are more desirable. Furthermore, the energy rays are not limited to ultraviolet light; any energy ray that has the property of curing ink depending on the properties of the ink is acceptable, and the light source can be replaced according to the wavelength of the energy ray.

[0025] The image reading sensor 34 is composed of an inline sensor (ILS) or the like, and reads an image formed on a recording medium. In this embodiment, the image data read by the image reading sensor 34 is sent to the image inspection device 50.

[0026] The paper output unit 40 stores the recording medium that has been fed out from the image forming unit 30. The paper output unit 40 has a plate-shaped paper output tray or the like, on which the image-formed recording medium is placed.

[0027] In this embodiment, an inkjet recording device is used as an example of the image forming apparatus 70, but it is not limited to this. Other image forming apparatuses, such as a color electrophotographic printer, or other image forming apparatuses of different types, such as an MFP (MultiFunction Peripheral), may also be used.

[0028] [Colorimeter] The colorimeter 60 is a device that quantifies the color of an object by spectrally analyzing the light reflected or transmitted by the object. In this embodiment, the colorimeter 60 measures the color of a recording medium on which a predetermined image has been formed in the image forming apparatus 70. In this embodiment, the colorimeter 60 measures the color of a patch image. The colorimeter data measured by the colorimeter 60 is used in the image inspection apparatus 50, which will be described later.

[0029] [Image inspection equipment] The image inspection device 50 is a device that inspects for defects in the image of a printed material output from the image forming apparatus 70, which consists of the print engine 35 and the image reading sensor 34 described above. The image inspection device 50 generates a first color conversion table in the first color conversion table generation unit 52 (see Figure 2), which will be described later, and creates a second color conversion table in the second color conversion table generation unit 54 (see Figure 2). Then, based on the created first color conversion table and second color conversion table, it converts the CMYK format image data to generate a reference image in RGB (Red, Green, Blue) format. The image inspection device 50 also compares the reference image generated by color conversion with the inspection image read by the image reading sensor 34 to perform an inspection process to determine whether or not there are defects. This embodiment is characterized by the image inspection method in the image inspection device 50. The image inspection method, including the procedure for generating the first color conversion table and the second color conversion table, will be described in detail later.

[0030] 2. Control configuration of the image forming system Next, the configuration of the control system of the image forming system 1 according to this embodiment will be described. Figure 2 is a block diagram showing the control system of the image forming system 1 according to this embodiment. As shown in Figure 2, the image forming system 1 according to this embodiment includes the DFE 10, print engine 35, image reading sensor 34, colorimeter 60, and image inspection device 50 as described above. The image inspection device 50 includes a patch analysis unit 51, a storage unit 53, a first color conversion table generation unit 52, a second color conversion table generation unit 54, a first color conversion processing unit 55, a second color conversion processing unit 56, and an inspection processing unit 57.

[0031] The patch analysis unit 51 extracts the RGB values ​​of each pixel in the read image data (patch image) sent from the image reading sensor 34 and extracts patch data in the RGB color space. In this embodiment, the patch analysis unit 51 extracts the first patch data RGB1 and the second patch data RGB2 at predetermined timings. The extraction timings of the first patch data RGB1 and the second patch data RGB2 will be explained in the image inspection method described later. The first patch data RGB1 is transmitted to and stored in the storage unit 53. On the other hand, the second patch data RGB2 is transmitted to the second color conversion table generation unit 54.

[0032] The first color conversion table generation unit 52 uses CMYK patch data in CMYK format obtained from the print engine 35 and color measurement data L of the patch image obtained from the colorimeter 60. * a * b * Based on the first patch data RGB1 (described later) obtained from the storage unit 53, a first color conversion table is generated. The second color conversion table generation unit 54 generates a second color conversion table based on the second patch data RGB2 obtained from the patch analysis unit 51 and the first patch data RGB1 obtained from the storage unit 53.

[0033] The storage unit 53 stores the first patch data RGB1, the first color conversion table, and the second color conversion table. The first color conversion processing unit 55 converts the CMYK format input image data D output from the DFE 10 based on the first color conversion table to generate the first reference image D1. The second color conversion processing unit 56 converts the first reference image D1 based on the second color conversion table to generate the second reference image D2. The inspection processing unit 57 performs inspection processing based on the second reference image D2 and the inspection image DS formed on the recording medium by the print engine 35 and scanned by the image reading sensor 34.

[0034] Incidentally, each component of the control system described above is controlled under the control of a control processing unit, which is not shown in the diagram. The control processing unit includes, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and non-volatile storage, each connected to a bus.

[0035] The CPU reads the program code of the software that implements each function according to this embodiment from ROM, loads it into RAM, and executes it. The control processing unit may include a processing unit such as an MPU (Micro-Processing Unit) instead of a CPU. Variables and parameters generated during the calculation process are temporarily written to RAM.

[0036] Examples of non-volatile storage include HDDs (Hard Disk Drives), SSDs (Solid State Drives), flexible disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, and non-volatile memory cards. This non-volatile storage stores the OS (Operating System), various parameters, and programs for operating the control processing unit. The programs may also be stored in ROM.

[0037] Programs are stored in the form of computer-readable program code, and the CPU sequentially executes operations according to that program code. In other words, ROM or non-volatile storage is used as an example of a computer-readable, non-transient recording medium that stores programs executed by a computer.

[0038] 3. Imaging examination methods Next, the image inspection method in the image forming system 1 of this embodiment will be described.

[0039] [Method for generating the first color conversion table (initial setup)] First, the method for generating the first color conversion table to be stored in the memory unit 53 will be explained. Figure 3 is a flowchart showing the method for generating the first color conversion table. Figure 4 is a diagram showing the control blocks used for generating the first color conversion table. In each part shown in Figure 4, the shaded parts are the components used when generating the first color conversion table.

[0040] The generation and setting of the first color conversion table are performed during the setup of the image forming apparatus 70 (image forming unit 30), and may be performed for each model, or for each user (each device). In this embodiment, the generation of the first color conversion table is shown as being performed during setup, but it may be performed in advance at a time before the start of the print job.

[0041] When initiating the initial setup, the DFE 10 prepares patch image data in CMYK format (input patch data CMYK) and sends it to the print engine 35 (step S1). Next, the print engine 35 prints the patch image onto a recording material based on the input patch data CMYK sent from the DFE 10 (step S2). Here, the recording material used in step S2 is a commonly used standard paper (standard paper). At this time, the input patch data CMYK output by the print engine 35 is sent to the first color conversion table generation unit 52 of the image inspection device 50.

[0042] Next, the image reading sensor 34 reads the printed material that has been printed and ejected by the print engine 35, where the patch image has been formed (step S3). The image of the patch image read by the image reading sensor 34 is transmitted to the patch analysis unit 51. The patch analysis unit 51 extracts the RGB values ​​of each pixel based on the read image data transmitted from step S2, and extracts the first patch data RGB1 in the RGB color space. The first patch data RGB1 extracted by the patch analysis unit 51 is transmitted to the storage unit 53 and stored.

[0043] On one hand, a patch image is formed in the print engine 35, and the printed matter discharged is colorimetrically measured using the colorimeter 60 (step S5). The colorimetric measurement in step S5 may be performed on the conveyance path of the printed matter discharged from the image forming apparatus 70, or as an example, the printed matter with the patch image formed by the user may be carried to the position of the colorimeter 60 for colorimetric measurement. The colorimetric data L of the patch image acquired by the colorimeter 60 * a * b * is transmitted to the first color conversion table generation unit 52.

[0044] Next, in the first color conversion table generation unit 52, based on the input patch data CMYK transmitted from the print engine 35, the colorimetric data L * a * b * transmitted from the colorimeter 60, and the first patch data RGB1 read from the storage unit 53, a first color conversion table is generated (step S6).

[0045] Fig. 5 shows the first color conversion table generated by the first color conversion table generation unit 52. As shown in Fig. 5, in the first color conversion table generation unit 52, a printer profile, a scanner profile, and a device link profile (first color conversion table) are generated.

[0046] The printer profile represents the correspondence relationship (output characteristics of the print engine) between the input image data (CMYK values) output to the print engine 35 and the color values (L * a * b * values) acquired from the printed matter. In this embodiment, with the color space of L * a * b * as the profile connection space (hereinafter referred to as PCS), a printer profile for estimating the colorimetric data L * a * b * from the input patch data CMYK is created.

[0047] The scanner profile consists of the reading values ​​(RGB values) from the image reading sensor 34 and the color values ​​(L) acquired from the object being read. * a * b * This represents the correspondence with the value (reading characteristics of the image reading sensor 34). In this embodiment, the color measurement data L * a * b * Using the PCS color space, the first patch data RGB1 is used to obtain the measured color data L * a * b * Create a scanner profile to estimate the value.

[0048] The device link profile (first color conversion table) represents the correspondence between the CMYK values ​​of the image data input to the print engine 35 and the readings (RGB values) of the image reading sensor 34. In this embodiment, the printer profile and the scanner profile are used to create a device link profile (first color conversion table) that shows the correspondence between the input patch data CMYK input to the print engine 35 and the first patch data RGB1 extracted by the patch analysis unit 51.

[0049] The first color conversion table shown in Figure 5 is transmitted to the storage unit 53 and stored in the storage unit 53.

[0050] The initial setup is completed as described above. As mentioned above, during the initial setup, the first color conversion table shown in Figure 5 and the first patch data RGB1 enclosed by the thick line in Figure 5 are stored in the storage unit 53.

[0051] [Method for generating a second color conversion table (paper profile)] Next, we will explain how to generate the second color conversion table that is performed when an actual print job is executed. Figure 6 is a flowchart showing how to generate the second color conversion table when a print job is executed. Figure 7 shows the control blocks used to generate the second color conversion table. In each part shown in Figure 7, the shaded parts are the parts used when generating the second color conversion table. The second color conversion table is a so-called print condition-specific profile, created for each print condition such as the type of paper used and print settings.

[0052] When the creation of the second color conversion table begins, the DFE10 first prepares the patch image data (input patch data CMYK) and sends it to the print engine 35 (step S10). The input patch data CMYK prepared in step S10 is the same as the input patch data CMYK in step S1 of Figure 3.

[0053] Next, the print engine 35 prints the patch image onto the recording material based on the CMYK input patch data sent from the DFE 10 (step S11). The recording material used in step S11 is the paper used in the actual job being executed.

[0054] Next, the image reading sensor 34 reads the recording material that has been printed and output by the print engine 35 (step S12). The image of the patch image read by the image reading sensor 34 is transmitted to the patch analysis unit 51.

[0055] The patch analysis unit 51 extracts the RGB values ​​of each pixel based on the read image data transmitted from step S12 and extracts the second patch data RGB2 in the RGB color space (step S13). The second patch data RGB2 extracted by the patch analysis unit 51 is transmitted to the second color conversion table generation unit 54.

[0056] Next, the second color conversion table generation unit 54 generates a second color conversion table from the first patch data RGB1, which was stored in the storage unit 53 during the initial setup, and the second patch data RGB2, which was extracted in step S13 (step S14).

[0057] Figure 8 shows an example of a second color conversion table generated in step S14. Figure 8 shows the correspondence between the first patch data RGB1 and the second patch data RGB2.

[0058] In this embodiment, for example, based on the data shown in Figure 8, matrix coefficients are calculated to estimate the second patch data RGB2 using matrix operations on the first patch data RGB1, and these matrix coefficients are used as the second color conversion table. An example of matrix operations using the color conversion table is shown in [Equation 1] below.

[0059]

number

[0060] As shown in [Equation 1] above, matrix coefficients are found to convert each value (R1, G1, B1) of the first patch data RGB1 to each value (R2, G2, B2) of the second patch data RGB2. In this case, for example, matrix coefficients M11 to M33 that minimize the error can be found, and these matrix coefficients M11 to M33 can be used as the second color conversion table.

[0061] The second color conversion table shown in Figure 8 or the matrix coefficients shown in [Equation 1] are transmitted to the storage unit 53 and stored in the storage unit 53. The second color conversion table is stored and managed in the storage unit 53 in association with the printing conditions such as the paper type and engine settings (ink / toner amount, gradation characteristics, etc.) at the time the second patch data RGB2 was acquired.

[0062] As described above, a second-color conversion table corresponding to the paper and engine settings used during the actual execution of a job is generated. The second-color conversion table may be generated immediately before each job is executed, or it may be generated when creating the profile for each type of paper. When the second-color conversion table is generated immediately before the job is executed, it is possible to reflect the type of paper used, the engine settings, as well as the characteristics of the print engine 35 and the image reading sensor 34 at that time.

[0063] [Imaging Examination Methods] Next, an image inspection method using the first color conversion table and the second color conversion table will be described. Figure 9 is a flowchart showing the image inspection method in the image inspection apparatus 50 of this embodiment. Figure 10 is a diagram showing the control block used during the image inspection described in Figure 9.

[0064] When a job related to image inspection is started, the DFE10 prepares input image data D based on the print job (step S20). The input image data D prepared here is the image data related to the actual print job entered by the user, and is RIP data in CMYK format. The input image data D prepared in step S20 is transmitted to the print engine 35 and the image inspection device 50.

[0065] The print engine 35 forms an image on a predetermined sheet of paper based on the input image data D (step S21). Subsequently, the image reading sensor 34 reads the recording material that has been printed and output by the print engine 35 (step S22). The read image (inspection image DS) read by the image reading sensor 34 is transmitted to the inspection processing unit 57 of the image inspection device 50.

[0066] Meanwhile, in the image inspection device 50, the input image data D transmitted from the DFE 10 is sent to the first color conversion processing unit 55, where it is color-converted (step S23). The first color conversion processing unit 55 converts the CMYK format input image data D based on the first color conversion table stored in the storage unit 53 to generate a first reference image D1 in RGB format. The first reference image D1 is an image color-converted based on the first patch data RGB1, and is image data that reflects the differences between each device. The first reference image D1 is sent to the second color conversion processing unit 56.

[0067] Next, the second color conversion processing unit 56 converts the first reference image D1 transmitted from the first color conversion processing unit 55 based on the second color conversion table stored in the storage unit 53, and generates the second reference image D2 (step S24). The second reference image D2 is an image that has been color converted based on the second patch data RGB2, and is image data that reflects the paper type, print settings, the print engine used when acquiring the second patch data, and the characteristics of the image reading sensor 34. The second reference image D2 is then transmitted to the inspection processing unit 57.

[0068] In the inspection processing unit 57, the inspection image DS, which is the image read from the image reading sensor 34, is compared with the second reference image D2, which is the image read from the second color conversion processing unit 56, and an inspection process is performed to check for any image defects in the inspection image (step S25). The inspection process in this embodiment may be performed for all pages in advance before the start of the print job, or it may be performed in real time for each page during the job.

[0069] In this embodiment, a first color conversion table can generate a first reference image D1 that reflects machine differences. Furthermore, in this embodiment, a second color conversion table can perform color conversion that reflects paper type, print settings, and changes over time. Therefore, the second reference image D2 is image data that reflects machine differences, paper type, print settings, and changes over time of the device compared to the original input image data D. This enables more accurate inspection processing.

[0070] Furthermore, in this embodiment, the first patch data RGB1 and the first conversion table only need to be stored in the storage unit beforehand. That is, in the inspection process performed for each job or each page, only the second patch data RGB2 needs to be acquired and the second color conversion table needs to be generated. Also, color measurement data is not required to generate the second color conversion table using the second patch data RGB2. Therefore, the colorimeter 60 is not required when generating the second color conversion table performed for each job or each page in the printing plant.

[0071] In this embodiment, the first color conversion table generation unit 52 is provided in the image inspection device 50, but it may also be configured to be performed in the DFE 10. In this case, the colorimetric data acquired by the colorimeter 60 and the first patch data RGB1 acquired by the patch analysis unit 51 are transmitted to the DFE 10 and stored in the DFE 10. Therefore, the image inspection device 50 only needs to be configured to store or be able to acquire information on the first color conversion table generated for each type of machine, or for each machine.

[0072] The embodiments described above are explained in detail to make the present invention easier to understand, and are not necessarily limited to those comprising all the configurations described. For example, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations. [Explanation of Symbols]

[0073] 1…Image forming system, 10…DFE, 20…Paper feeding unit, 30…Image forming unit, 31…Image forming drum, 32…Head unit, 33…Irradiation unit, 34…Image reading sensor, 35…Print engine, 40…Paper discharge unit, 50…Image inspection device, 51…Patch analysis unit, 52…First color conversion table generation unit, 53…Storage unit, 54…Second color conversion table generation unit, 55…First color conversion processing unit, 56…Second color conversion processing unit, 57…Inspection processing unit, 60…Colorimeter, 70…Image forming apparatus

Claims

1. A first color conversion processing unit generates a first basic image by converting the input image data input to the print engine based on a first color conversion table generated based on first patch data acquired in advance, and A second color conversion processing unit generates a second basic image by color-converting the first basic image based on a second color conversion table generated based on second patch data acquired under different printing conditions and / or timings than when the first patch data was acquired, An inspection processing unit performs image inspection by comparing the aforementioned second basic image with an inspection image obtained by reading the image on the recording medium output from the print engine with an image reading sensor, Equipped with Image inspection device.

2. The first color conversion table is generated based on input patch data input to the print engine, first patch data obtained by reading the patch image output from the print engine based on the input patch data with an image reading sensor, and color measurement data obtained by measuring the color of the patch image with a colorimeter. The image inspection apparatus according to claim 1.

3. The first color conversion table converts the input patch data in CMYK format to L ＊ a ＊ b ＊ It is generated from a printer profile that estimates the color measurement data in the color space, and a scanner profile that estimates the color measurement data from the first patch data in RGB format. The image inspection apparatus according to claim 2.

4. The second color conversion table is generated based on the first patch data and the second patch data obtained by reading the patch image output from the print engine based on the input patch data using an image reading sensor. The image inspection apparatus according to claim 2.

5. The system includes a storage unit that stores the first patch data and the first color conversion table, The first color conversion processing unit performs color conversion processing using the first color conversion table stored in the storage unit. The image inspection apparatus according to claim 4.

6. The system includes a second color conversion table generation unit that generates the second color conversion table from the first patch data and the second patch data, The second color conversion table generation unit acquires the second patch data and reads the first patch data from the storage unit when a job is executed to generate the second color conversion table. The image inspection apparatus according to claim 5.

7. The second patch data is stored in the storage unit in association with the printing conditions, including the paper settings and / or print settings of the job at the time the second patch data is acquired. The image inspection apparatus according to claim 6.

8. A print engine that prints images onto a recording medium, The system includes an image inspection device for inspecting images output from the print engine, The aforementioned image inspection device is A first color conversion processing unit generates a first basic image by converting the input image data input to the print engine based on a first color conversion table generated based on first patch data acquired in advance, and A second color conversion processing unit that converts the first basic image to color and generates a second basic image based on a second color conversion table generated based on second patch data acquired under different printing conditions and / or timing than when the first patch data was acquired, The system includes an inspection processing unit that compares the second basic image with an inspection image obtained by reading the image on the recording medium output from the print engine using an image reading sensor, and performs inspection. Image forming system.

9. The steps include: generating a first basic image by color-converting the input image data input to the print engine based on a first color conversion table generated based on first patch data acquired in advance; The steps include: color-converting the first base image and generating a second base image based on a second color conversion table acquired under different printing conditions and / or timings than when the first patch data was acquired; The computer is instructed to perform the following steps: compare the second basic image with an inspection image obtained by reading the image on the recording medium output from the print engine using an image reading sensor, and then perform inspection. program.

Images