Image inspection device, image inspection program, and image inspection method

Abstract

To provide an image inspection device, an image inspection program, and an image inspection method capable of improving alignment accuracy between an inspection image upon image inspection and a reference image.SOLUTION: An image inspection device is provided with: an attachment section for attaching a reference pattern for alignment to image data; an image forming section for forming the image based on the image data to which the reference pattern is attached, in a storage medium; a reading section for generating a read image through reading the image formed in the storage medium; and an inspection section for performing comparison inspection between the inspection image based on the read image and the reference image. The attachment section generates a reference pattern in a shape identifiable by the inspection section despite resolution of the inspection image during image inspection.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image inspection device, an image inspection program, and an image inspection method. [Background technology]

[0002] Conventionally, there is known a technology for performing image inspection by performing a comparative inspection between an inspection image based on a read image obtained by reading an image based on image data to which a reference pattern for alignment during image inspection has been added and a reference image (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-14759 Summary of the Invention [Problem to be solved by the invention]

[0004] However, depending on the resolution of the inspection image, the reference pattern may disappear or become faint, which may result in a problem of reduced accuracy in aligning the inspection image with the reference image during image inspection.

[0005] An object of the present invention is to provide an image inspection device, an image inspection program, and an image inspection method that are capable of improving the accuracy of alignment between an inspection image and a reference image during image inspection. [Means for solving the problem]

[0006] The image inspection device according to the present invention comprises: an adding unit that adds a reference pattern for alignment to image data; an image forming unit that forms an image based on the image data to which the reference pattern has been added on a recording medium; a reading unit that reads an image formed on the recording medium and generates a read image; an inspection unit that performs a comparison inspection between an inspection image based on the read image and a reference image; Equipped with During image inspection, the adding unit generates the reference pattern in a shape that can be identified by the inspection unit, regardless of the resolution of the inspection image.

[0007] The image inspection program according to the present invention comprises: An image inspection program executed by an image inspection device, On the computer, An addition process of adding a reference pattern for alignment to the image data; an image forming process for forming an image based on the image data to which the reference pattern has been added on a recording medium; A reading process for reading an image formed on the recording medium and generating a read image; an inspection process for performing a comparison inspection between an inspection image based on the read image and a reference image; Run the command, The additional processing includes processing for generating the reference pattern in a shape that can be identified by the image inspection device during image inspection, regardless of the resolution of the inspection image.

[0008] The image inspection method according to the present invention comprises: An image inspection method for use in an image inspection device, comprising: adding a reference pattern for alignment to the image data; forming an image based on the image data to which the reference pattern has been added on a recording medium; A step of reading an image formed on the recording medium to generate a read image; performing a comparison inspection between an inspection image based on the read image and a reference image; having The adding step includes a step of generating the reference pattern in a shape that can be identified by the image inspection device during image inspection, regardless of the resolution of the inspection image. Effect of the Invention

[0009] According to the present invention, it is possible to improve the accuracy of alignment between an inspection image and a reference image during image inspection. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an overall configuration of an image inspection system according to an embodiment of the present invention. [Diagram 2] 1 is a block diagram showing a main functional configuration of an image forming apparatus; [Diagram 3] FIG. 1 is a diagram showing a recording medium on which an example of a register mark is formed. [Figure 4] FIG. 4 is an enlarged view of the crop mark portion in FIG. [Diagram 5] FIG. 4 is an enlarged view of the center register portion in FIG. [Figure 6] FIG. 13 is a diagram showing a recording medium on which an example of a reference pattern is formed. [Figure 7] FIG. 7 is an enlarged view of a portion of the reference pattern in FIG. 6 that corresponds to the crop mark. [Figure 8] FIG. 7 is an enlarged view of a portion of the reference pattern in FIG. 6 that corresponds to the center register mark. [Figure 9] FIG. 13 is a diagram showing an example of a setting screen for a reference pattern. [Figure 10] FIG. 13 is a diagram showing an example of a setting screen for a reference pattern. [Figure 11] 5 is a flowchart showing an example of processing operation of the image inspection system according to the present embodiment. [Figure 12] FIG. 4 is a diagram showing an example of an image read by two reading units. [Figure 13] 13 is a diagram showing an example in which a reference pattern is applied to the scanned image of FIG. 12. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a diagram showing a schematic overall configuration of an image inspection system 1 according to an embodiment of the present invention.

[0012] The image inspection system 1 is a system capable of inspecting an image formed on a recording medium P. Specifically, the image inspection system 1 inspects the image by reading the image formed on the recording medium P and performing a comparison inspection between an inspection image generated based on the read image and a reference image. The image inspection system 1 has an image forming apparatus 1A and an inspection apparatus 100. The image inspection system 1 corresponds to the "image inspection apparatus" of the present invention. The inspection apparatus 100 corresponds to the "inspection unit" of the present invention.

[0013] The image forming apparatus 1A is an inkjet type image forming apparatus that records an image on a recording medium P. The image forming apparatus 1A includes a paper feed section 10, an image forming section 20, a paper discharge section 30, and a control section 40.

[0014] Under the control of the control unit 40, the image forming apparatus 1A transports the recording medium P stored in the paper feed unit 10 to the image forming unit 20, ejects ink onto the recording medium P in the image forming unit 20 to record an image, and transports the recording medium P with the image recorded thereon to the paper discharge unit 30.

[0015] In detail, the image forming apparatus 1A records a color image on the recording medium P by overlapping and outputting the four colors, yellow (Y), magenta (M), cyan (C), and black (K), on the recording medium P at a predetermined number of recording gradations.

[0016] As the recording medium P, in addition to paper such as plain paper or coated paper, various media capable of fixing the ink that has landed on the surface, such as fabric or sheet-like resin, can be used.

[0017] The paper feed unit 10 has a paper feed tray 11 that stores the recording medium P, and a medium supply unit 12 that transports and supplies the recording medium P from the paper feed tray 11 to the image forming unit 20. The medium supply unit 12 has a ring-shaped belt supported by two rollers on the inside, and transports the recording medium P from the paper feed tray 11 to the image forming unit 20 by rotating the rollers with the recording medium P placed on this belt.

[0018] The image forming section 20 includes a conveying section 21, a delivery unit 22, a head unit 23, an irradiation section 24, a reading section 25, a delivery section 27, and the like.

[0019] The conveying section 21 holds the recording medium P placed on the conveying surface of a cylindrical conveying drum 211, and conveys the recording medium P on the conveying drum 211 in a conveying direction along the conveying surface by the conveying drum 211 rotating and moving in a circular motion around a rotation axis (cylindrical axis) extending in the X direction perpendicular to the drawing in FIG. 1.

[0020] The transport drum 211 has claws and an air suction section (not shown) for holding the recording medium P on the transport surface. The recording medium P is held on the transport surface by having its edges pressed down by the claws and being sucked to the transport surface by the air suction section.

[0021] The transfer unit 22 is provided at a position between the medium supply section 12 of the paper feeding section 10 and the conveying section 21, and holds and picks up one end of the recording medium P conveyed from the medium supply section 12 with a swing arm section 221, and hands it over to the conveying section 21 via the transfer drum 222.

[0022] The head unit 23 records an image by ejecting ink onto the recording medium P from nozzle openings provided on an ink ejection surface facing the transport surface of the transport drum 211 at appropriate timing according to the rotation of the transport drum 211 on which the recording medium P is held.

[0023] The head units 23 are disposed such that the ink ejection surface and the transport surface are spaced apart by a predetermined distance. In the image forming apparatus 1A of the present embodiment, the four head units 23 corresponding to the four colors of ink, Y, M, C, and K, are arranged at predetermined intervals from the upstream side in the transport direction of the recording medium P in the order of Y, M, C, and K. In other words, each head unit 23 is configured to be capable of ejecting a plurality of different types of ink.

[0024] The head unit 23 is used in a fixed position when recording an image, and records an image using a single pass method by sequentially ejecting ink at predetermined intervals (transport direction intervals) to different positions in the transport direction as the recording medium P is transported.

[0025] The irradiation unit 24 is disposed across the width of the transport unit 21 in the X direction, and irradiates the recording medium P placed on the transport unit 21 with electromagnetic waves (e.g., ultraviolet rays) to harden and fix the ink ejected onto the recording medium P. The irradiation unit 24 is disposed facing the transport surface downstream of the position where the head unit 23 is disposed in the transport direction.

[0026] The reading unit 25 is, for example, a scanner or other reading device capable of reading an image formed on the recording medium P transported through the transport unit 21. The reading unit 25 is disposed opposite the transport surface downstream of the position where the irradiation unit 24 is disposed in the transport direction.

[0027] The delivery section 27 has a belt loop 272 having a circular belt supported by two rollers on the inside, and a cylindrical transfer drum 271 that transfers the recording medium P from the conveying section 21 to the belt loop 272. The recording medium P transferred from the conveying section 21 to the belt loop 272 by the transfer drum 271 is transported by the belt loop 272 and sent to the paper discharge section 30.

[0028] The paper discharge section 30 has a plate-shaped paper discharge tray 31 on which the recording medium P sent out from the image forming section 20 by the delivery section 27 is placed.

[0029] 2 is a block diagram showing the main functional configuration of the image forming apparatus 1A. The image forming apparatus 1A includes a control unit 40, a head unit driving unit 50, a transport driving unit 60, an image processing unit 70, an operation unit 80, and an addition unit 90.

[0030] The control unit 40 has a central processing unit (CPU) 41, a random access memory (RAM) 42, a read only memory (ROM) 43, and a storage unit 44, and controls the overall operation of the image forming apparatus 1A.

[0031] The CPU 41 reads out various control programs and setting data stored in the ROM 43, stores them in the RAM 42, and executes the programs to perform various arithmetic processing.

[0032] The RAM 42 provides a working memory space for the CPU 41 and stores temporary data. The RAM 42 may include a non-volatile memory.

[0033] The ROM 43 stores various control programs and setting data executed by the CPU 41. Note that the ROM 43 may be replaced with a rewritable non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory.

[0034] The storage unit 44 stores a print job input from an external device (not shown) via the operation unit 80, image data of an image to be recorded by the print job, and the like. As the storage unit 44, for example, a HDD (Hard Disk Drive) is used, and a DRAM (Dynamic Random Access Memory) or the like may also be used in combination.

[0035] Based on the control of the control unit 40, the head unit drive unit 50 supplies drive signals corresponding to image data to the recording elements of the head unit 23 at appropriate timing, thereby causing the nozzles of the head unit 23 to eject an amount of ink corresponding to the pixel values ​​of the image data.

[0036] The transport drive unit 60 supplies a drive signal to a transport drum motor provided on the transport drum 211 based on a control signal supplied from the control unit 40, thereby rotating the transport drum 211 at a predetermined speed and timing. The transport drive unit 60 also supplies a drive signal to a motor for operating the medium supply unit 12, the delivery unit 22, and the delivery unit 27 based on a control signal supplied from the control unit 40, thereby supplying the recording medium P to the transport unit 21 and discharging it from the transport unit 21.

[0037] The image processing unit 70 performs a predetermined image processing on the image data stored in the storage unit 44, and stores the obtained image data in the storage unit 44. This image processing includes a correction process for correcting the image data by applying a correction table (not shown) to the image data, as well as a color conversion process, a gradation correction process, a pseudo halftone process, and the like.

[0038] The operation unit 80 is an input / output interface of the image forming apparatus 1A, and is connected to an input / output interface of an external device (e.g., the inspection device 100) to mediate the transmission and reception of data between the control unit 40 and the external device. The operation unit 80 is configured, for example, with any one of various serial interfaces, various parallel interfaces, or a combination of these.

[0039] The adding unit 90 executes a process of adding, to the image data, a reference pattern for alignment during image inspection by the inspection device 100. The reference pattern is, for example, a pattern based on a register mark that is a marker for the cutting position of the recording medium P.

[0040] As shown in FIG. 3, the register marks include corner register marks T1 arranged at positions corresponding to the four corners of the recording medium P, and a center register mark T2 arranged at the center position between the two corner register marks T1.

[0041] As shown in Fig. 4, the crop mark T1 is composed of two L-shaped lines L1 and L2. The L-shaped lines L1 and L2 are arranged so as to intersect with each other. A portion L11 of the L-shaped line L1 that is parallel to the vertical direction (first direction) is arranged so as to be located more inward of the recording medium P than a portion L21 of the L-shaped line L2 that is parallel to the vertical direction. A portion L22 of the L-shaped line L2 that is parallel to the horizontal direction (second direction perpendicular to the first direction) is arranged so as to be located more inward of the recording medium P than a portion L12 of the L-shaped line L1 that is parallel to the horizontal direction.

[0042] Portion L11 of L-shaped line L1 is parallel to cutting line D1 in the first direction of recording medium P and corresponds to the cutting position in the first direction. Portion L22 of L-shaped line L2 is parallel to cutting line D2 in the second direction of recording medium P and corresponds to the cutting position in the second direction. Portion L11 and portion L22 correspond to the "parallel portion" of the present invention.

[0043] As shown in Fig. 5, the center crop mark T2 is composed of a crosshair. The crosshair is composed of a central portion C1 and an orthogonal portion C2. The central portion C1 is a portion corresponding to the center position between two crop marks T1 aligned in the first or second direction.

[0044] The orthogonal portion C2 is a portion that is perpendicular to the central portion C1 and is arranged parallel to the cutting line of the recording medium P. When the orthogonal portion C2 is a center register mark T2 that corresponds to the center position of two corner register marks T1 lined up in a first direction, the orthogonal portion C2 is arranged parallel to the cutting line D1 in the first direction. When the orthogonal portion C2 is a center register mark T2 that corresponds to the center position of two corner register marks T1 lined up in a second direction, the orthogonal portion C2 is arranged parallel to the cutting line D2 in the second direction. FIG. 5 illustrates a center register mark T2 in which the orthogonal portion C2 is parallel to the cutting line D2 in the second direction. The orthogonal portion C2 corresponds to the "parallel portion" of the present invention.

[0045] Furthermore, during image inspection, the adding unit 90 generates a reference pattern based on the above-mentioned register marks in a shape that can be identified by the inspection device 100. The generation of the reference pattern by the adding unit 90 will be described in detail later.

[0046] The inspection device 100 has a CPU, RAM, ROM, and a storage unit, and is a device that performs a comparative inspection between a read image read by the reading unit 25 and a reference image. The inspection device 100 of this embodiment is, for example, a device such as a personal computer that can communicate with the image forming apparatus 1A via a network. Note that the inspection device 100 is not limited to this, and may be provided in the image forming apparatus 1A, such as the control unit 40. The inspection device 100 corresponds to the "inspection unit" of the present invention.

[0047] The reference image is an image that serves as a reference for image inspection, and is an image based on an image formed on recording medium P by image forming apparatus 1A before image inspection. The reference image may be an image read by reading unit 25, or may be an image based on image data that has been RIP (Raster Image Processor) processed.

[0048] The test image is an image to be inspected, and is based on a read image generated by reading an image formed on recording medium P by image forming apparatus 1A with reading unit 25.

[0049] The inspection device 100 can execute a process of converting the resolution of a read image. For example, the inspection device 100 converts the read image into a lower resolution image for high-speed processing of image inspection. In this embodiment, the reference image and the inspection image are images obtained by converting the image read by the reading unit 25 into a lower resolution image. The inspection device 100 corresponds to the "resolution conversion unit" of the present invention.

[0050] First, before image inspection, the inspection device 100 acquires information on a read image corresponding to a reference image, and generates a reference image by reducing the resolution of an image based on the acquired information.

[0051] Furthermore, the inspection device 100 generates a registration model that provides good registration accuracy from a reference image of the target. For example, a shape model and an NCC model are known as registration algorithms. The shape model is an image that extracts feature points from image edges and performs registration of the feature points. The NCC model is an image that performs registration by image matching (registration by normalized cross-correlation of the target region).

[0052] Then, the inspection device 100 associates the generated alignment model with the reference image and registers it in a storage unit (not shown) or the like.

[0053] Next, the inspection device 100 acquires information of a read image based on the image formed on the recording medium P in the image forming unit 20, and reduces the resolution of the image based on this information to generate an inspection image.

[0054] Furthermore, the inspection apparatus 100 searches for a registration location based on a registration model associated with a reference image corresponding to the target inspection image. The inspection apparatus 100 aligns the target inspection image or the reference image based on the registration information.

[0055] Then, inspection device 100 performs a comparison inspection between the inspection image and the reference image, and records the inspection results in an inspection report.

[0056] However, when the resolution of an image is reduced, the resolution of the register mark (reference pattern) added to the image data for alignment is also reduced, so there is a possibility that the register mark cannot be identified when the inspection device 100 aligns the image inspection. For example, when the resolution of an image is reduced, the image is reduced in size, so that the register mark, which is smaller than the image to be inspected, is likely to disappear or become faint as the image is reduced in size.

[0057] For example, suppose that the image to be inspected (the image formed on the non-cut portion of the recording medium P) is an image that is likely to disappear when the image is reduced (for example, an image with only ruled lines). In this case, if the register marks disappear or become faint, the image to be inspected may disappear as well as the register marks, and therefore everything that serves as a reference for comparison during the comparative inspection may disappear. As a result, there is a risk that alignment itself may not be possible.

[0058] Therefore, in this embodiment, as described above, the adding unit 90 generates a reference pattern in a shape that can be identified by the inspection device 100 during image inspection. Specifically, as shown in Fig. 6, the adding unit 90 generates a reference pattern so that a parallel portion of the register mark that is parallel to the cutting line of the recording medium P is extended to the opposite side to the non-cut portion of the recording medium P.

[0059] The non-cut portion of the recording medium P is a portion on the recording medium P on which an image to be inspected in the image inspection is formed, and is a portion surrounded by the cutting lines D1 and D2.

[0060] For example, as shown in Fig. 7, in the crop mark T1 in the reference pattern, the adding unit 90 expands the portion L11 and the portion L22. For the portion L11, the adding unit 90 expands the portion L11 so that it becomes thicker to the left side in Fig. 7 relative to the cutting line D1 along the first direction. For the portion L22, the adding unit 90 expands the portion L22 so that it becomes thicker to the upper side in Fig. 7 relative to the cutting line D2 along the second direction.

[0061] Also, as shown in FIG. 8, in the center register mark T2 in the reference pattern, the adding portion 90 expands the orthogonal portion C2 so as to become thicker toward the upper side in FIG. 8 with respect to the cutting line D2.

[0062] The range in which the reference pattern is extended is within the printable area in the image forming unit 20. Therefore, the adding unit 90 may extend the reference pattern up to the boundary between the printable area and the non-printable area (the dot portion in FIG. 8, etc.). Also, the adding unit 90 does not have to extend the reference pattern up to the boundary between the printable area and the non-printable area, and may change the extension range of the reference pattern depending on the resolution of the inspection image.

[0063] For example, when a comparison inspection is performed with the resolution in the first direction of the inspection image set to 1 / N (N is a positive real number equal to or greater than 1) of the read image (setting at times other than image inspection), the addition unit 90 may expand the number of pixels in the first direction in the parallel portion of the reference pattern to more than N. Also, when a comparison inspection is performed with the resolution in the second direction of the inspection image set to 1 / M (M is a positive real number equal to or greater than 1) of the read image, the addition unit 90 may expand the number of pixels in the second direction in the parallel portion of the reference pattern to more than M.

[0064] For example, when the resolution during image inspection is set to 1 / 10 of the scanned image, the portion of the reference pattern with fewer than 10 pixels will disappear or become faint as the resolution is lowered. However, in this embodiment, the portion of the reference pattern with fewer than 10 pixels is reliably expanded to 10 pixels or more, so it will not disappear even when the resolution is lowered.

[0065] In this way, a reference pattern can be generated in a shape that can be identified by inspection device 100, regardless of the resolution of the inspection image.

[0066] Moreover, the image forming unit 20 may form an image corresponding to the reference pattern using one color out of YMCK (multiple colors).

[0067] If a reference pattern is generated in multiple colors, color shifts between the colors may cause problems in aligning the inspection image with the reference image. However, by forming the reference pattern in one of the multiple colors, color shifts can be prevented and the accuracy of aligning the inspection image with the reference image can be improved.

[0068] Furthermore, the above-mentioned reference pattern may be set by the user via the operation unit 80. In other words, when the user selects a reference pattern via the operation unit 80, the adding unit 90 may add the reference pattern to the image data.

[0069] The setting of the reference pattern may be, for example, a setting as to whether or not to add the reference pattern to the image data.

[0070] For example, when the user checks the check box for the reference pattern on the setting screen shown in Fig. 9, the reference pattern is added to the image data. In addition to the reference pattern, the setting screen shown in Fig. 9 shows additional items such as date and time, file name, page, etc.

[0071] Furthermore, the operation unit 80 may be capable of setting the type of reference pattern, the position and size of the reference pattern, and the like.

[0072] The types of reference patterns may include a normal reference pattern and a reference pattern for image inspection. The normal reference pattern may be a reference pattern used at times other than image inspection, for example, a normal registration mark for cutting (see FIG. 3). The reference pattern for image inspection is a reference pattern used during image inspection, and may be a pattern that is larger than the normal reference pattern (see FIG. 6). For example, when the user checks the checkbox for image inspection on the setting screen shown in FIG. 10, the type of reference pattern is set to the reference pattern for image inspection.

[0073] The position and size of the reference pattern may include a margin from the edge of the recording medium P, and a width and height of the reference pattern. The position and size of the reference pattern are set based on numerical values ​​input by the user via the operation unit 80. For example, the margin, width and height are set by the user inputting numerical values ​​on the setting screen shown in Fig. 10. In this way, the position and size of the reference pattern can be adjusted according to the user's preference.

[0074] The display of the setting screen shown in Fig. 10 may be able to transition from the display of the setting screen shown in Fig. 9. For example, when the user inputs "details" on the setting screen shown in Fig. 6, the display may transition to the setting screen shown in Fig. 7.

[0075] Furthermore, during image inspection, values ​​corresponding to a shape that can be identified by inspection device 100 may be set as default values ​​in operation unit 80 for the position and size of the reference pattern, regardless of the resolution of the inspection image. In other words, during image inspection, default values ​​may be input in advance into the margin, width, and height fields in Fig. 10. This can save the user the trouble of inputting the position and size of the reference pattern.

[0076] Next, a control flow of the image inspection system 1 according to the present embodiment will be described. Fig. 11 is a flowchart showing an example of the processing operation of the image inspection system 1 according to the present embodiment. Note that the processing of Fig. 11 is appropriately executed, for example, when the setting of a print job of a reference image for image inspection is executed.

[0077] 11, the inspection device 100 executes the setting of a job of a reference image (step S101). The setting of the job of the reference image may be executed based on an input by the user via the operation unit 80, for example.

[0078] As the job setting of the reference image is executed, the adding unit 90 adds the reference pattern to the image data (step S102). Note that the reference pattern does not have to be added during the job setting of the reference image, and may be added before the processing of step S101, for example. Then, the image inspection system 1 executes the job of the reference image (step S103).

[0079] Specifically, the control unit 40 forms an image corresponding to the reference image on the recording medium P, and the reading unit 25 acquires the read image. Then, the inspection device 100 reduces the resolution of the read image and registers it as the reference image. Note that, if the reference image is an image based on image data that has been RIP (Raster Image Processor) processed, the process of step S103 does not need to be executed.

[0080] After step S103, the inspection device 100 executes the setting of the image inspection job (step S104). The setting of the image inspection job may be executed based on the user's input via the operation unit 80, for example. The setting of the image inspection job may be, for example, the setting of areas to be excluded from inspection, and the setting of the inspection level of each area. The setting of the image inspection job may also include the setting of the processing content (for example, continue, stop, recover and resume, etc.) when an inspection defect is detected during the image inspection job (for example, detection of waste paper, etc.).

[0081] After step S104, the image inspection system 1 executes an image inspection job (step S105). Specifically, the control unit 40 forms an image of the inspection target on the recording medium P, and the reading unit 25 acquires the read image. Then, the inspection device 100 compares and inspects an inspection image, which is a low-resolution version of the read image, with a reference image.

[0082] After step S105, the image inspection system 1 determines whether the image inspection job has been completed (step S106). If the result of the determination is that the image inspection job has not been completed (step S106, NO), the process of step S106 is repeated.

[0083] On the other hand, when the image inspection job is completed (step S106, YES), the inspection device 100 outputs an inspection report (step S107), and then this control ends.

[0084] According to the present embodiment configured as described above, during image inspection, the adding unit 90 generates a reference pattern in a shape that can be identified by the inspection device 100, regardless of the resolution of the inspection image.

[0085] This allows the inspection device 100 to reliably identify the reference pattern even if the resolution of the inspection image is reduced during image inspection. As a result, the accuracy of alignment between the inspection image and the reference image during image inspection can be improved.

[0086] Furthermore, the image forming unit 20 forms an image corresponding to the reference pattern in one of the multiple colors. If the reference pattern is formed in multiple colors, color shift may occur, which may cause problems in alignment during image inspection. However, in this embodiment, there is no risk of color shift, and therefore it is possible to improve the accuracy of alignment between the inspection image and the reference image.

[0087] In addition, the reference pattern is a pattern based on a register mark that includes a parallel portion parallel to the cutting line of the recording medium P, and the addition unit 90 generates the reference pattern so as to extend the parallel portion to the opposite side to the non-cut portion of the recording medium P.

[0088] Since the register mark is configured in a linear shape, when the resolution is reduced, the line portion is likely to disappear or become faint. In contrast, in this embodiment, the parallel portion of the register mark is expanded by the adding unit 90, so that even when the resolution is reduced, the parallel portion of the register mark can be prevented from disappearing or becoming faint. As a result, the accuracy of alignment between the inspection image and the reference image can be improved.

[0089] In addition, since the range in which the reference pattern is expanded is within the printable area in the image forming unit 20, the reference pattern can be reliably formed on the recording medium P. As a result, during image inspection, the inspection image and the reference image can be reliably aligned.

[0090] Furthermore, when the addition unit 90 performs a comparison inspection by setting the resolution in the first direction in the inspection image to 1 / N (N is a positive real number greater than or equal to 1) of the resolution of the read image, the number of pixels in the first direction in the parallel portion is expanded to more than N. Furthermore, when the addition unit 90 performs a comparison inspection by setting the resolution in the second direction in the inspection image to 1 / M (M is a positive real number greater than or equal to 1) of the resolution of the read image, the number of pixels in the second direction in the parallel portion is expanded to more than M.

[0091] This makes it possible to prevent the reference pattern from disappearing or becoming smudged even if the resolution is lower than that of the read image during image inspection, thereby ensuring alignment of the inspection image with the reference image.

[0092] The registration mark also includes two center registration marks formed in the center of the width direction of the recording medium P so as to sandwich the non-cut portion of the recording medium P, and the additional portion 90 extends the parallel portions of each of the four corner registration marks and the parallel portions of each of the two center registration marks.

[0093] Here, for example, in an image forming apparatus 1A capable of forming an image on a wide recording medium P such as A3 size, a plurality of reading units 25 may be provided side by side in the width direction (the direction corresponding to the second direction) of the recording medium P. In such a case, as shown in FIG. 12, the read image in each reading unit 25 is an image obtained by dividing the image formed on the recording medium P.

[0094] 12 shows an example of a read image when two reading units 25 read an image of one recording medium P. P1 is a read image read by one of the two reading units 25. P2 is a read image read by the other of the two reading units 25.

[0095] The read image P1 includes two center register marks T2 that sandwich the image (non-cut portion) formed on the recording medium P in the first direction (vertical direction) and a corner register mark T1 that corresponds to one of both ends in the second direction (horizontal direction). The read image P2 includes two center register marks T2 that sandwich the image (non-cut portion) formed on the recording medium P in the first direction and a corner register mark T1 that corresponds to the other end of the image in the second direction.

[0096] For example, if two center register marks sandwiching the non-cut portion in the first direction are not formed, the read image obtained by dividing the image formed on the recording medium P in this way will only include a corner register mark corresponding to one or the other of both ends in the second direction. In other words, each read image will only have a reference pattern on one or the other side in the second direction, which may cause problems with alignment.

[0097] In contrast, in this embodiment, two center register marks T2 are formed to sandwich the non-cut portion of the recording medium P, so that each read image includes two reference patterns located on both sides in the second direction. As a result, by expanding the register marks of each read image (see FIG. 13), even if the image is divided in each read image, it is possible to reliably align the inspection image with the reference image.

[0098] Furthermore, the center register mark located in the center in the first direction may or may not be expanded.

[0099] In the above embodiment, the resolution of the read image is reduced by the inspection device 100 (inspection unit), but the present invention is not limited to this, and the resolution may be reduced by the image forming device 1A. For example, the image forming device 1A may have a resolution conversion unit, which reduces the resolution of the read image read by the reading unit 25 with settings other than those for image inspection, and outputs the reduced resolution to the inspection device 100. Also, the image forming device 1A may output the read image read by the reading unit 25 with a resolution lower than the settings other than those for image inspection as an inspection image to the inspection device 100. In this case, the reading unit 25 corresponds to the "resolution conversion unit" of the present invention.

[0100] In the above embodiment, the inspection device 100 performs a comparative inspection during image inspection using an inspection image with a lower resolution than the settings during non-image inspection, but the present invention is not limited to this. For example, the inspection device 100 may perform a comparative inspection during image inspection using an inspection image that is the same as the settings during non-image inspection. In this case, the reference pattern may be, for example, a pattern shown in FIG. 6 or the like.

[0101] Further, in the above embodiment, the image forming unit 20 forms an image corresponding to the reference pattern using one of the multiple colors, but the present invention is not limited to this, and an image corresponding to the reference pattern may be formed using two or more of the multiple colors.

[0102] In addition, in the above embodiment, the reference pattern was set based on input from the user via the operation unit 80, but the present invention is not limited to this, and the reference pattern may be set automatically, without via the operation unit 80.

[0103] In addition, in the above embodiment, the reference pattern was a pattern based on a registration mark, but the present invention is not limited to this, and the reference pattern may be a pattern other than a registration mark, such as a shape that follows the cutting line or a shape that has a portion parallel to the cutting line.

[0104] In addition, in the above embodiment, an inkjet type image forming apparatus is exemplified, but the present invention is not limited to this and may be an image forming apparatus other than an inkjet type (for example, an electrophotographic type image forming apparatus, etc.).

[0105] In addition, the above-mentioned embodiments are merely examples of the embodiment of the present invention, and the technical scope of the present invention should not be interpreted as being limited by them. In other words, the present invention can be embodied in various forms without departing from the gist or main characteristics of the present invention. [Explanation of symbols]

[0106] 1. Image inspection system 1A Image forming device 10 Paper feed section 11 Paper feed tray 12 Media supply section 20 Image forming section 21 Conveyor 22 Delivery Unit 23 Head Unit 24 Irradiation unit 25 Reading unit 27 Delivery Department 30 Paper output section 31 Paper output tray 40 Control section 50 Head unit drive section 60 Conveyor drive unit 70 Image Processing Section 80 Control section 90 Addition 100 Inspection Equipment 211 Transport drum 221 Swing arm part 222 Delivery Drum 271 Delivery Drum 272 Belt loop

Claims

1. an adding unit that adds a reference pattern for alignment to image data; an image forming unit that forms an image based on the image data to which the reference pattern has been added on a recording medium; a reading unit that reads an image formed on the recording medium and generates a read image; an inspection unit that performs a comparison inspection between an inspection image based on the read image and a reference image; Equipped with the adding unit generates the reference pattern in a shape that can be identified by the inspection unit during image inspection, regardless of the resolution of the inspection image. Image inspection equipment.

2. Further comprising a resolution conversion unit capable of executing a process of converting the resolution of the image data, the inspection unit performs the comparison inspection using an inspection image having a resolution lower than that of the read image during the image inspection.

2. The image inspection device according to claim 1.

3. The image forming unit includes: The image can be formed on the recording medium using a plurality of colors; forming an image corresponding to the reference pattern using one of the plurality of colors; 2. The image inspection device according to claim 1.

4. the reference pattern is a mark for a cutting position of the recording medium, and is a pattern based on a register mark including a parallel portion parallel to a cutting line of the recording medium; the adding unit generates the reference pattern so as to extend the parallel portion to an opposite side to the non-cut portion of the recording medium.

2. The image inspection device according to claim 1.

5. the range in which the reference pattern is expanded is within a printable area in the image forming unit; 5. The image inspection device according to claim 4.

6. The addition unit is When the comparison inspection is performed with a resolution in the first direction of the inspection image being set to 1 / N (N is a positive real number equal to or greater than 1) of the resolution of the read image, the number of pixels in the first direction in the parallel portion is expanded to N or more; When the comparison inspection is performed by setting the resolution of the inspection image in a second direction perpendicular to the first direction to 1 / M (M is a positive real number equal to or greater than 1) of the resolution of the read image, the number of pixels in the second direction in the parallel portion is expanded to M or more.

5. The image inspection device according to claim 4.

7. The register marks include four corner register marks formed at positions corresponding to the four corners of the recording medium, and two center register marks arranged at the center of the width direction of the recording medium so as to sandwich an uncut portion of the recording medium, The adding unit extends the parallel portions of the four corner crop marks and the parallel portions of the two center crop marks.

5. The image inspection device according to claim 4.

8. Further comprising an operation unit operable by a user, the adding unit adds the reference pattern to the image data when the user selects the reference pattern via the operation unit.

2. The image inspection device according to claim 1.

9. The adding unit makes the reference pattern used during the image inspection larger than a reference pattern used during a time other than the image inspection.

2. The image inspection device according to claim 1.

10. Further comprising an operation unit operable by a user, the position and size of the reference pattern are set based on numerical input by a user via the operation unit; 2. The image inspection device according to claim 1.

11. Regarding the position and size of the reference pattern, values ​​corresponding to a shape that can be identified by the inspection unit are set as default values ​​of the operation unit during the image inspection, regardless of the resolution of the inspection image. The image inspection device according to claim 10.

12. the reference image is generated by reading an image formed on the recording medium by the reading unit.

2. The image inspection device according to claim 1.

13. The reference image is an image based on image data that has been RIP-processed.

2. The image inspection device according to claim 1.

14. An image inspection program executed by an image inspection device, On the computer, An addition process of adding a reference pattern for alignment to the image data; an image forming process for forming an image based on the image data to which the reference pattern has been added on a recording medium; A reading process for reading an image formed on the recording medium and generating a read image; an inspection process for performing a comparison inspection between an inspection image based on the read image and a reference image; Run the command, The additional processing includes a process of generating the reference pattern in a shape that can be identified by the image inspection device during image inspection, regardless of the resolution of the inspection image. Image inspection program.

15. An image inspection method for use in an image inspection device, comprising: adding a reference pattern for alignment to the image data; forming an image based on the image data to which the reference pattern has been added on a recording medium; A step of reading an image formed on the recording medium to generate a read image; performing a comparison inspection between an inspection image based on the read image and a reference image; having the step of adding includes a step of generating the reference pattern in a shape that can be identified by the image inspection device during image inspection, regardless of the resolution of the inspection image. Imaging methods.

Images