Inspection system

Abstract

To appropriately control reprinting when a defect is detected in inspection.SOLUTION: An inspection system includes an image forming unit that forms an image on a sheet, an inspection unit that inspects the sheet on which the image is formed, and a control unit that controls the image forming unit to form an image on a sheet in a first operation mode in which an entire job for forming images on a plurality of sheets is executed or a second operation mode in which the job is partially tried. The inspection unit executes inspection of a sheet on which an image has been formed by the image forming unit in both the first and second operation modes. When a defect is detected as a result of the inspection in the first operation mode, the controller causes the image former to form a corresponding image again, and when a defect is detected as a result of the inspection in the second operation mode, the controller does not cause the image former to form a corresponding image again.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to an inspection system. [Background technology]

[0002] An image forming apparatus forms an image on a sheet based on input image data representing the image to be printed, and outputs the printed matter. In commercial printing, when printing a large number of pages or copies at once, a so-called proof print may be performed, in which only a portion of the job is printed. Cited Document 1 discloses a system that makes it easy for a job manager to check the execution status of the proof print job and the execution status of the actual print job.

[0003] There is also known a technology that automatically inspects whether printing has been performed properly by comparing a scanned image generated by optically scanning a printed material with a reference image. Patent Document 2 discloses a system that inspects variable data such as text and barcodes according to user settings in addition to inspecting the image portion of a printed material based on image comparison. Patent Document 3 discloses a system that can eject printed material detected as defective as a result of inspection to an escape tray different from the usual ejection destination and reprint the same image on another sheet. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-184155 [Patent Document 2] Japanese Patent Publication No. 2023-159012 [Patent Document 3] Japanese Patent Application Publication No. 2023-176860 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a system that has the function of not only performing actual printing but also performing test printing, there is no known literature that clearly discloses how to reprint when defects are detected during inspection. While it is possible to not activate the inspection function during test printing, in that case, a human would have to visually check the test printout, which may prevent sufficient identification of areas for improvement before the actual printing. On the other hand, performing a uniform inspection and even performing a test printout would waste consumable materials such as sheets and toner.

[0006] In view of the above-mentioned circumstances, the present disclosure aims to provide a mechanism that can appropriately control reprinting when a defect is detected during inspection. [Means for solving the problem]

[0007] According to one aspect, an inspection system is provided that includes an image forming unit that forms an image on a sheet, an inspection unit that inspects the sheet on which the image has been formed, and a control unit that controls the image forming unit to form the image on the sheet in a first operating mode in which an entire print job for forming images on multiple sheets is executed, or in a second operating mode in which a portion of the print job is attempted, wherein the inspection unit inspects the sheet on which the image has been formed by the image forming unit in both the first operating mode and the second operating mode, and the control unit, in the first operating mode, if a defect is detected as a result of the inspection, causes the image forming unit to re-form an image corresponding to the sheet on which the defect was detected, and in the second operating mode, if a defect is detected as a result of the inspection, does not cause the image forming unit to re-form an image corresponding to the sheet on which the defect was detected. [Effects of the Invention]

[0008] According to the present disclosure, reprinting can be appropriately controlled when a defect is detected during inspection. [Brief explanation of the drawings]

[0009] [Figure 1]FIG. 1 is a schematic diagram showing an example of the configuration of an inspection system according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of a control device according to an embodiment. [Figure 3] FIG. 2 is a block diagram showing an example of the configuration of an inspection control unit according to an embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing an example of a print setting screen. [Figure 5] FIG. 10 is an explanatory diagram showing an example of an examination setting screen. [Figure 6A] FIG. 10 is an explanatory diagram showing a first example of a test print setting screen. [Figure 6B] FIG. 10 is an explanatory diagram showing a second example of a test print setting screen. [Figure 6C] FIG. 10 is an explanatory diagram showing a third example of a test print setting screen. [Figure 7] 10 is a flowchart showing an example of the flow of a print control process according to an embodiment. [Figure 8] 10 is a flowchart showing an example of the flow of a regular printing process involving reprinting. [Figure 9] 10 is a flowchart showing an example of the flow of a test printing process that does not involve reprinting. [Figure 10] 10 is a flowchart showing an example of the flow of a print control process according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] <1. System Overview> 1 is a schematic diagram showing an example of the configuration of an inspection system 1 according to an embodiment. Referring to FIG. 1, the inspection system 1 includes an operation unit 100, an image forming apparatus 200, a control device 400, an inspection apparatus 500, a stacker 600, and a finisher 700.

[0012] (1)Operation unit The operation unit 100 is a device that provides a user with a user interface consisting of an input interface and an output interface. The input interface may include, for example, one or more of input keys, a touch panel, a button, and a switch. The output interface may include, for example, one or more of a display, a speaker, and a lamp. The operation unit 100 accepts user input via the input interface and transmits instruction signals or data corresponding to the accepted user input to the control device 400. Furthermore, the operation unit 100 outputs information from the output interface (for example, displays an image on the display or outputs sound from the speaker) based on a command received from the control device 400.

[0013] (2) Image forming device Image forming apparatus 200 is a device (also called a printer) that prints an image on a sheet and outputs the printed sheet. In this embodiment, image forming apparatus 200 is a color printer capable of forming a color image. In another embodiment, image forming apparatus 200 may be a monochrome printer. Image forming apparatus 200 includes image forming units 300Y, 300M, 300C, and 300K, an intermediate transfer member 306, a transfer unit 307, a fixing unit 308, a cleaner 309, paper feed cassettes 311 and 312, and a feed mechanism.

[0014] Image forming unit 300Y forms a yellow (Y) toner image on intermediate transfer body 306. Image forming unit 300M forms a magenta (M) toner image on intermediate transfer body 306. Image forming unit 300C forms a cyan (C) toner image on intermediate transfer body 306. Image forming unit 300K forms a black (K) toner image on intermediate transfer body 306. Since image forming units 300Y, 300M, 300C, and 300K have the same configuration, the configuration of image forming unit 300Y will be described as an example. Image forming unit 300Y includes a photosensitive drum 301, a charger 302, an exposure unit 303, and a developer 304. Photosensitive drum 301 is a drum-shaped photosensitive body with a photosensitive layer on its surface. Photosensitive drum 301 rotates around its axis in the direction of arrow R in the figure. The charger 302 uniformly charges the surface of the rotating photosensitive drum 301. The exposure unit 303 irradiates the photosensitive drum 301 with laser light in accordance with image data (representing a yellow image in this case) input from the control device 400. The laser light output from the exposure unit 303 scans the charged surface of the photosensitive drum 301 in the drum axial direction, thereby forming an electrostatic latent image on the surface of the photosensitive drum 301. The developing unit 304 develops the electrostatic latent image on the photosensitive drum 301 by supplying toner (yellow in this case) to the surface of the photosensitive drum 301. As a result, a toner image is formed on the surface of the photosensitive drum 301. The yellow toner image formed on the surface of the photosensitive drum 301 in the image forming unit 300Y is transferred to an intermediate transfer body 306. Furthermore, the magenta, cyan, and black toner images formed on the surfaces of the respective photosensitive drums 301 in the image forming units 300M, 300C, and 300K are transferred in order to the intermediate transfer body 306 in a state where they are superimposed on the yellow toner image. As a result, a full-color toner image is formed on the intermediate transfer body 306. The intermediate transfer body 306 is an endless belt member that rotates clockwise in the drawing. The intermediate transfer body 306 transports the full-color toner image to the position (transfer position) of the transfer unit 307.

[0015] Sheet feed cassettes 311 and 312 store stacks of sheets. A sheet is picked up from sheet feed cassette 311 or 312 by a feeding mechanism and transported along a transport path 313. Under the control of control device 400, the sheet is transported to the transfer position in synchronization with the time when the toner image on intermediate transfer body 306 reaches the transfer position.

[0016] Transfer unit 307 transfers the toner image carried on intermediate transfer body 306 to a sheet at the transfer position. Fixing unit 308 includes a heater and a pressure roller. Fixing unit 308 heats the toner image transferred to the sheet with the heater and presses it with the pressure roller, thereby melting the toner on the sheet and fixing the toner image to the sheet. Cleaner 309 is located downstream of the transfer position on the path of intermediate transfer body 306 and removes toner remaining on intermediate transfer body 306 after the toner image has been transferred.

[0017] The conveying path 313 branches into conveying paths 314 and 315 downstream of the fixing device 308. The sheet that has passed through the fixing device 308 is conveyed from the conveying path 313 to the conveying path 315. When the trailing end of the sheet enters the conveying path 315, the conveying direction is reversed, and the sheet is discharged from the discharge rollers 317 to the inspection device 500. Through this conveying process, the sheet is discharged with the side on which the image has been formed facing downward (referred to as face-down). When double-sided printing is performed, the sheet that has entered the conveying path 315 is conveyed to the conveying path 316, and then returns from the conveying path 316 to the conveying path 313, where it passes through the transfer position again in an inverted state. At the transfer position, a toner image is formed on the back side of the sheet by the transfer unit 307, and the toner image is fixed to the sheet by the fixing device 308. The sheet with images formed on both sides is discharged from the discharge rollers 317 to the inspection device 500.

[0018] (3) Control device The control device 400 controls the operations of the image forming device 200, the inspection device 500, the stacker 600, and the finisher 700 based on instruction signals received from the operation unit 100 or an external network. The control device 400 may be part of the image forming device 200 or the inspection device 500. For example, when a user instructs execution of a print job, the control device 400 controls the image forming device 200 to print an image based on specified input image data on a sheet. The configuration of the control device 400 will be described in more detail later.

[0019] (4) Inspection equipment The inspection device 500 includes a conveyance path 501, conveyance rollers 502, a flow reading glass 503a, a flow reading glass 503b, a conveyance roller 504, a first reading unit 505a, a second reading unit 505b, and an inspection control unit 510. The conveyance rollers 502 receive a sheet (also referred to as a printed sheet) output from the image forming apparatus 200 and convey the sheet along the conveyance path 501. The first reading unit 505a optically reads the lower surface of the sheet passing over the flow reading glass 503a to generate a read image and outputs the read image data to the inspection control unit 510. The first reading unit 505a irradiates the sheet with white light from, for example, one or more white light-emitting diodes (LEDs). The first reading unit 505a can read the image of the sheet by detecting the light reflected from the lower surface of the sheet using, for example, the pixel array of a complementary metal oxide semiconductor (CMOS) sensor. Typically, the first reading unit 505a separates reflected light from the sheet into three color components using RGB color filters and receives the light. Therefore, the read image data output from the first reading unit 505a is raster-format data representing a three-dimensional vector having three RGB color component values ​​for each pixel. The second reading unit 505b optically reads the upper surface of the sheet passing under the flow reading glass 503b to generate a read image and outputs the read image data to the inspection control unit 510. The second reading unit 505b may be configured similarly to the first reading unit 505a, and the read image data output from the second reading unit 505b is also raster-format data representing a three-dimensional vector having three RGB color component values ​​for each pixel. The conveying rollers 504 discharge the sheet that has passed through the flow reading glasses 503a and 503b into the stacker 600. The inspection control unit 510 controls the operation of the inspection device 500 in cooperation with the control device 400. The configuration of the test control unit 510 will be described in more detail later.

[0020] (5) Stacker The stacker 600 includes conveying paths 601, 602, 603, and 604, a large-capacity tray 610, and a purge tray 620. The stacker 600 receives sheets delivered from the inspection device 500 onto the conveying path 601. The conveying path 601 branches into a conveying path 602 leading to the large-capacity tray 610, a conveying path 603 leading to the purge tray 620, and a conveying path 604 leading to the finisher 700. For example, a printed sheet detected as defective by the inspection device 500 (hereinafter referred to as a defective sheet) can be discharged to the purge tray 620 through the conveying path 603 under the control of the control device 400. Furthermore, sheets that require post-processing by the finisher 700 can be discharged to the finisher 700, and other sheets can be discharged to the large-capacity tray 610.

[0021] (6) Finisher The finisher 700 is a post-processing device that includes a conveying path 701 and discharge trays 711, 712, and 713. The finisher 700 receives sheets delivered from the stacker 600 onto the conveying path 701, and discharges the sheets onto any of the discharge trays 711, 712, and 713 under the control of the control device 400. Although not shown, the finisher 700 may include a mechanism for performing various post-processing operations, such as stapling, binding, or cutting, on multiple sheets.

[0022] <2. Example of control device configuration> Fig. 2 is a block diagram showing an example of the configuration of the control device 400. The control device 400 is connected to the above-mentioned operation unit 100, image forming device 200, inspection device 500, stacker 600, and finisher 700, but Fig. 2 does not show the connections between the control device 400 and the stacker 600 and finisher 700. The control device 400 is further connected to a storage 430 and a power control unit 450.

[0023] The control device 400 includes a CPU 401, a ROM 402, a RAM 403, an NVRAM 404, and a timer 405. The CPU (Central Processing Unit) 401 is a processor that controls the overall operation of the inspection system 1 by executing computer programs including software instructions. The ROM (Read Only Memory) 402 is a non-volatile memory that stores one or more computer programs executed by the CPU 401. The RAM (Random Access Memory) 403 is a volatile memory that provides a temporary storage area for processing by the CPU 401. The RAM 403 may also be used as an image memory that temporarily stores image data. The NVRAM (Non-Volatile RAM) 404 is a small-scale non-volatile memory that stores values ​​of various parameters required to control the operation of the inspection system 1. The timer 405 is used to obtain the current time and monitor the passage of a set time. The CPU 401, ROM 402, RAM 403, NVRAM 404, and timer 405 are connected to each other via a system bus 410.

[0024] The control device 400 further includes interfaces (I / Fs) such as an operation I / F 406, a printer control I / F 407, a power control I / F 408, a network I / F 409, an image bus I / F 411, a storage I / F 417, and an ACC I / F 418. These interfaces are also interconnected via a system bus 410. The operation I / F 406 connects the control device 400 to the operation unit 100. The printer control I / F 407 is an interface that mediates control communication between the control device 400 and the image forming device 200. The power control I / F 408 connects the control device 400 to a power control unit 450. The power control unit 450 supplies power from a power source (not shown) to each device constituting the inspection system 1 in a timely manner in accordance with commands input from the CPU 401 via the power control I / F 408. The network I / F 409 connects the control device 400 to an external network (not shown). The control device 400 can communicate with an external device (e.g., a host computer) via a network I / F 409. The network I / F 409 may be, for example, a wired local area network (LAN) interface or a wireless LAN interface. For example, input image data (e.g., PDL (Page Description Language) data) required to execute a print job may be received from an external device via the network I / F 409. The network I / F 409 may have a memory that stores communication control parameters such as address information (e.g., MAC address and IP address) of the control device 400. The image bus I / F 411 is a bridge that mediates the connection between the system bus 410 and the image bus 415. The storage I / F 417 connects the control device 400 to a storage 430. The storage 430 is a large-capacity storage device. The storage 430 may be, for example, a hard disk drive (HDD) or a solid state drive (SSD). The ACC I / F 418 connects the control device 400 to the inspection device 500 .

[0025] The control device 400 further includes an image processing unit 412, a RIP 413, and a printer I / F 414. The image bus I / F 411, the image processing unit 412, the RIP 413, and the printer I / F 414 are interconnected via an image bus 415. The image processing unit 412 performs image processing on image data, such as compressing or decompressing the image data according to some image compression method, rotating the image to correct skew, correcting pixel values, converting color space, or converting resolution. The RIP (Raster Image Processor) 413 converts PDL data into image data (RIP data) in raster format (also called bitmap format). The printer I / F 414 is an interface that mediates image data communication between the control device 400 and the image forming device 200. Input image data for a print job is rasterized by RIP 413 and converted into RIP data, and then further processed by image processing unit 412 (e.g., color space conversion from RGB to YMCK), and then output to image forming device 200 via printer I / F 414.

[0026] In this embodiment, the CPU 401 of the control device 400 functions as a print control unit 420 that controls the printing operation of the image forming device 200. The print control unit 420 causes the image forming device 200 to execute a print job in an operation mode selected by the user from a plurality of operation modes including a first operation mode and a second operation mode. Here, the first operation mode is a regular printing mode, and the second operation mode is a test printing mode. These operation modes will be described in detail later.

[0027] <3. Configuration example of inspection control unit> 3 is a block diagram showing an example of the configuration of the inspection control unit 510. The inspection control unit 510 includes a CPU 511, a ROM 512, a RAM 513, a storage 514, a host I / F 515, a motor driver 516, a sensor I / F 517, a comparison unit 518, an RTC 519, and an image processing unit 531.

[0028] The CPU 511 is a processor that controls the operation of the inspection device 500 by executing a computer program including software instructions. The ROM 512 is a non-volatile memory that stores one or more computer programs executed by the CPU 511. The RAM 513 is a volatile memory that provides temporary storage for processing by the CPU 511. The RAM 513 may also be used as an image memory that temporarily stores image data. The storage 514 may be a storage device such as a HDD or SSD and may store various data. The host I / F 515 connects the inspection control unit 510 to the ACC I / F 418 of the control device 400. For example, when an image requiring inspection is printed, the host I / F 515 receives raster-format input image data (RIP data) corresponding to the image from the control device 400. The received input image data is stored in the storage 514 as reference image data representing a reference image for inspection, as described below. Instead of input image data for a print job, read image data obtained by optically reading a printed sheet on which a reference image has been printed satisfactorily may be used as the reference image data.

[0029] Under the control of the CPU 511, the motor driver 516 drives a motor (not shown) for rotating multiple rollers in the inspection device 500 so that the sheet is transported along the transport path inside the inspection device 500 at the appropriate time. A sensor I / F 517 connects the inspection control unit 510 to a sensor for detecting the position of the sheet passing through the transport path 501. A comparison unit 518 compares the read image represented by the read image data with a reference image to inspect the printed sheet. Inspection based on image comparison in the comparison unit 518 will be described in more detail later. An RTC (Real Time Clock) 519 is a clock that measures real time with high precision. Synchronization between sheet transport and image reading in the inspection device 500 can be maintained based on the timekeeping by the RTC 519. The CPU 511 , ROM 512 , RAM 513 , storage 514 , host I / F 515 , motor driver 516 , sensor I / F 517 , comparison unit 518 , RTC 519 , and image processing unit 531 are connected to one another via a system bus 520 .

[0030] The inspection control unit 510 further includes a first reading I / F 532a and a second reading I / F 532b. The first reading I / F 532a connects the inspection control unit 510 to the first reading unit 505a shown in FIG. 1. The first reading I / F 532a acquires read image data of a first surface (the lower surface in FIG. 1) of a sheet from the first reading unit 505a and outputs the acquired read image data to the image processing unit 531. The second reading I / F 532b connects the inspection control unit 510 to the second reading unit 505b shown in FIG. 1. The second reading I / F 532b acquires read image data of a second surface (the upper surface in FIG. 1) of a sheet from the second reading unit 505b and outputs the acquired read image data to the image processing unit 531. The image processing unit 531 performs image processing such as magnification and gamma correction on the scanned image data acquired via the first scanning I / F 532a and the second scanning I / F 532b. The image processing unit 531 then outputs the processed scanned image data to the RAM 513, for example, for comparison between the scanned image and a reference image by the comparison unit 518. In the following description, the CPU 511, comparison unit 518, and image processing unit 531 will be collectively referred to as the inspection unit 530. The inspection unit 530 is not limited to the above example, and may be realized as a single processing circuit.

[0031] <4. Actual printing mode and test printing mode> As described above, the print control unit 420 controls the image forming apparatus 200 to execute a print job in an operating mode selected by the user from the regular print mode and the test print mode. In the regular print mode, the print control unit 420 causes the image forming apparatus 200 to execute the entire print job spanning multiple sheets. In the test print mode, the print control unit 420 causes the image forming apparatus 200 to test print a portion of the print job spanning multiple sheets. The portion printed in the test print mode may be M copies out of the total number of copies N (N and M are natural numbers, N>M), or Q pages out of the number of pages P (P and Q are natural numbers, P>Q), or a combination thereof.

[0032] Typically, the user confirms that printing has been performed without errors and with acceptable quality in the proof printing mode, and then has the inspection system 1 execute the entire print job in the actual printing mode. The inspection unit 530 inspects the printed sheets output from the image forming apparatus 200 in both the actual printing mode and the proof printing mode, and outputs inspection result data indicating the inspection results. The inspections performed by the inspection unit 530 will be described in more detail below. By having the inspection unit 530 execute inspections and output inspection result data even in the proof printing mode, the user can efficiently determine whether preparations for the actual printing have been made by looking at the inspection result data.

[0033] In this printing mode, if a defect is detected as a result of the inspection, the print control unit 420 causes the image forming apparatus 200 to reprint the image corresponding to the defective sheet. As described above, the defective sheet can be discharged to the purge tray 620 of the stacker 600. When there are two or more printed sheets to be output in this printing mode and a defect is detected as a result of inspecting a printed sheet, the print control unit 420 causes the image forming apparatus 200 to perform the reprint and then continue printing on the subsequent sheet. Because reprinting is automatically performed based on the inspection results in this printing mode, it is possible to provide the user with a complete set of printed materials without any defects, even when printing a large number of pages or copies at once, such as in commercial printing situations.

[0034] Inspection unit 530 reinspects printed sheets output from image forming apparatus 200 as a result of reprinting (re-image formation) of an image corresponding to a defective sheet. When the number of times the same image has been reprinted by image forming apparatus 200 reaches an upper limit, print control unit 420 will not cause image forming apparatus 200 to reprint the image even if a defect is detected during the reinspection. By setting an upper limit on the number of reprints in this way, it is possible to prevent unnecessary reprints caused by the same defect.

[0035] In the test printing mode, if a defect is detected as a result of the inspection, the print control unit 420 does not cause the image forming apparatus 200 to reprint the image corresponding to the defective sheet. This is because defects are likely to be detected in test printing due to a variety of causes, such as incorrect print settings or incorrect inspection settings, and uniformly reprinting results in wasting consumable materials such as sheets and toner and unnecessarily increasing the number of work steps. When there are two or more printed sheets to be output in the test printing mode, if a defect is detected as a result of the inspection of a printed sheet, whether or not to continue printing on subsequent sheets may be controlled depending on the type of defect, as described below.

[0036] In one embodiment described below, reprinting may be performed in the proof printing mode when a defect is detected, depending on user settings. As in the regular printing mode, when the maximum number of times the same image can be reprinted in the proof printing mode is reached, the print control unit 420 does not cause the image forming apparatus 200 to reprint the image. The maximum number of reprints in this embodiment may be different from the maximum number of reprints imposed in the regular printing mode.

[0037] <5. Imaging tests and variable tests> <5-1. Imaging Tests> In this embodiment, the inspection unit 530 inspects each printed sheet output from the image forming apparatus 200 by comparing the scanned image of the printed sheet with a reference image. In this specification, this inspection is referred to as image inspection. For example, the inspection unit 530 may detect a defect in a printed sheet when the result of comparing the scanned image with the reference image satisfies at least one of the following defect conditions: - The scanned image has stains or streaks that are not present in the reference image. The difference in color between the scanned image and the reference image exceeds the threshold. The positional deviation between the scanned image and the reference image exceeds the threshold. Defects detected in such image inspection are referred to as "type 1 defects" in this specification. Type 1 defects are based on a mismatch between the scanned image and the reference image. If the comparison result does not satisfy any of the defect conditions, the inspection unit 530 may determine that there are no defects in the printed sheet.

[0038] For image inspection, the user may set an inspection area, an inspection level, and an exclusion area. The inspection area is a partial area within the scanned image that should be inspected. The inspection level indicates the degree of mismatch between the scanned image and the reference image that should be detected as a defect. Depending on the inspection level set by the user, the size of the stain or streak that is deemed a defect under the above-mentioned defect conditions, or a threshold value to be compared with the difference in color or positional deviation, may be determined. A different inspection level may be set for each inspection area. As an example, the inspection level is expressed as a number such as 1 to 3 or 1 to 5, with a higher number indicating a more detailed inspection (or vice versa). The exclusion area is a partial area within the scanned image that should not be inspected.

[0039] <5-2. Variable Testing> In addition to (or instead of) the image inspection described above, the inspection unit 530 may be capable of performing the following variable inspection. Variable inspection refers to an inspection for the presence of a specific element, which is variably set by the user, in the scanned image. The specific element may include, for example, at least one of a character string and a code in which information is encoded. For example, the inspection unit 530 may search for a specific character string within an inspection area set in advance by the user using optical character recognition (OCR) technology, and if the presence of the specific character string is not detected, determine that the printed sheet is defective. The character string may be variable, such as a serial number that is counted up for each copy. Similarly, the inspection unit 530 may search for a code, such as a barcode or QR code (registered trademark), within an inspection area set in advance by the user using known code detection technology, and if the presence of the specific code is not detected, determine that the printed sheet is defective.

[0040] Defects detected in this variable inspection are referred to as second-type defects in this specification. The second-type defects are based on the failure to detect a specific element in an inspection area set by the user. If the target element is found in the inspection area, the inspection unit 530 can determine that there are no defects in the printed sheet.

[0041] When two or more printed sheets are to be output in the proof printing mode, if a second-type defect is detected as a result of inspecting one printed sheet, the print control unit 420 may cause the image forming apparatus 200 to stop printing on subsequent sheets. This is because the cause of incorrect recognition of specific elements, such as text or codes, is often a user setting error, such as an incorrect positioning of the inspection area or an incorrect specification of the text or code. If such a setting error is found, it is desirable to immediately stop the proof printing and prompt the user to correct the setting. On the other hand, if a first-type defect is detected as a result of inspecting a printed sheet, the print control unit 420 may cause the image forming apparatus 200 to continue printing on subsequent sheets. This is because first-type defects, such as stains and streaks, do not necessarily recur on subsequent sheets. The results of printing on subsequent sheets may be useful in determining the cause of the defect.

[0042] <6. Example of setting screen> <6-1. Print setting screen> Fig. 4 is an explanatory diagram showing an example of a print setting screen according to an embodiment. The print setting screen 110 shown in Fig. 4 may be displayed on the operation unit 100 or the display of an external device, for example, when a user instructs the inspection system 1 to execute a print job. The print setting screen 110 includes a first setting button 111, a second setting button 112, a third setting button 113, a fourth setting button 114, an inspection setting button 115, a proof printing setting button 116, a cancel button 117, a proof printing button 118, and a start printing button 119.

[0043] The first setting button 111 is a button for setting the color mode (color or monochrome). The second setting button 112 is a button for setting single-sided printing or double-sided printing. The third setting button 113 is a button for setting the type of sheet to be used for printing. Depending on the operation of the third setting button 113, it may be possible to display information such as the size and basis weight of the sheets stored in each cassette and change the cassette to be used. The fourth setting button 114 is a button for setting which output tray the sheets will be output to.

[0044] The inspection setting button 115 is a button for calling up an inspection setting screen, which will be described later. When the user operates the inspection setting button 115, the inspection setting screen, which will be described later using FIG. 5, is called up. The proof printing setting button 116 is a button for calling up a proof printing setting screen, which will be described later using FIG. 6A to FIG. 6C, when the user operates the proof printing setting button 116.

[0045] The cancel button 117 is a button for canceling the execution of the print job and closing the print setting screen 110. The proof print button 118 is a button for starting proof printing, i.e., a partial test of the print job. The start print button 119 is a button for starting actual printing, i.e., the execution of the entire print job.

[0046] <6-2. Test setting screen> 5 is an explanatory diagram showing an example of an examination setting screen. The examination setting screen 120 includes a first button 121, a first level selection field 122, a second button 123, a second level selection field 124, a third button 125, a fourth button 126, a fifth button 127, a cancel button 128, an OK button 129, and an area designation section 130.

[0047] A preview of the input image of the print job is displayed in the area specification section 130. The user can set a priority inspection area where priority inspection should be performed by operating the first button 121 to specify a desired range in the area specification section 130 (for example, by dragging). The user can also select the inspection level of the priority inspection area in the first level selection field 122. Similarly, the user can set a standard inspection area where standard inspection should be performed by operating the second button 123 to specify a desired range in the area specification section 130. The user can also select the inspection level of the standard inspection area in the second level selection field 124. These inspection areas are the targets of image inspection.

[0048] The user can also set a character string inspection area where character string inspection should be performed by operating third button 125 and specifying a desired range in area specification section 130. The user can also set a code inspection area where code inspection should be performed by operating fourth button 126 and specifying a desired range in area specification section 130. These inspection areas are the targets of variable inspection. Although not shown in FIG. 5, a further detailed setting screen may be provided that allows the user to specify the character strings and codes to be searched for in each inspection area.

[0049] The user can set an exclusion area to be excluded from the inspection by operating the fifth button 127 and specifying a desired range in the area specification section 130. The part set as the exclusion area can be excluded from the image inspection and the variable inspection.

[0050] In the example of FIG. 5, one priority inspection area 131, one standard inspection area 132, and one character string inspection area 133 are set within the image, as shown by the respective frames in the area designation section 130.

[0051] 5, the inspection settings screen 120 may include additional buttons for transitioning between multiple pages of previews in the area specification section 130. A cancel button 128 is a button for canceling the setting changes and returning to the print settings screen 110. An OK button 129 is a button for registering the setting changes in the system and returning to the print settings screen 110.

[0052] <6-3. Test print setting screen> 6A to 6C are explanatory diagrams showing first to third examples of the test print setting screen, respectively. In the first example of Fig. 6A, the test print setting screen 150a includes a range selection field 151, a file path input field 157, a cancel button 158, and an OK button 159.

[0053] In the range selection field 151, the user can select the range of the test print from options such as "only the first sheet" and "all sheets of the first copy." The file path input field 157 is a field that accepts input of the file path to which the data file of the inspection result data is output. The inspection result data may not only be output as a data file, but may also be displayed on the inspection result screen. The cancel button 158 is a button for canceling the setting changes and returning to the print setting screen 110. The OK button 159 is a button for registering the setting changes in the system and returning to the print setting screen 110.

[0054] In the first example, even if a defect is detected as a result of the inspection in the test printing mode, the image corresponding to the defective sheet is not reprinted. In contrast, in the second example, the user can set whether or not to reprint the image corresponding to the defective sheet in the test printing mode.

[0055] In the second example of FIG. 6B, a test print setting screen 150b includes a range selection field 151, radio buttons 152 and 153, an upper limit number input field 154, a file path input field 157, a cancel button 158, and an OK button 159.

[0056] Radio buttons 152 and 153 are buttons that accept a selection of whether or not to reprint the image corresponding to the defective sheet. A user who desires reprinting selects radio button 152, while a user who does not desire reprinting selects radio button 153. The upper limit number input field 154 is a field that is enabled when radio button 152 is selected and accepts input of the upper limit number of reprints in test printing mode. When radio button 152 is selected, thereby indicating that the user's settings indicate that the image corresponding to the defective sheet should be reprinted, the print control unit 420 causes the image forming apparatus 200 to reprint the image as long as the upper limit number of reprints does not exceed the upper limit. By allowing the user to set the upper limit number of reprints specific to the test printing mode in this way, consumption of consumables in test printing can be flexibly reduced. On the other hand, when radio button 153 is selected, thereby indicating that the user's settings indicate that reprinting should not be performed, the print control unit 420 does not cause the image forming apparatus 200 to reprint the image corresponding to the defective sheet.

[0057] In the next third example, the user can set whether printing on sheets following a defective sheet should be continued or stopped in the test printing mode for each type of defect.

[0058] In the third example of FIG. 6C, the test print setting screen 150c includes a range selection field 151, an upper limit number of times input field 154, a first operation selection field 155, a second operation selection field 156, a file path input field 157, a cancel button 158, and an OK button 159.

[0059] In the first action selection field 155, the user can select an action to be taken when a first type of defect, such as a stain or streak, is detected during image inspection. In the second action selection field 156, the user can select an action to be taken when a second type of defect, such as a specific character string or code not being correctly detected during variable inspection, is detected. The options here may be two or more of "reprint and continue," "continue without reprinting," and "abort without reprinting." For example, the default setting for the first type of defect may be "continue without reprinting," and the default setting for the second type of defect may be "abort without reprinting." The maximum number of reprints input field 154 is enabled when "reprint and continue" is selected for at least one of the first type of defect and the second type of defect, and receives input of the maximum number of reprints.

[0060] <7. Processing flow> This section uses flowcharts to explain some examples of the flow of processes that can be executed by the print control unit 420 and the inspection unit 530. In each flowchart, 'S' denotes a processing step.

[0061] (1) Print control process Fig. 7 is a flowchart showing an example of the flow of a print control process according to an embodiment. The print control process in Fig. 7 is started in response to a user operating, for example, the test print button 118 or the start print button 119 on the print setting screen 110 in Fig. 4.

[0062] First, in S11, the print control unit 420 acquires the input image data and basic settings for the print job. The basic settings may include, for example, the number of copies to be printed, color mode, single-sided / double-sided, sheet type, and output destination. Here, it is assumed that printing across multiple sheets has been instructed.

[0063] Next, in S12, the print control unit 420 acquires inspection-related settings. The inspection-related settings may include, for example, one or more inspection areas set by the user, an inspection level for each inspection area, an inspection type for each inspection area, a string in the case of a string inspection, a code in the case of a code inspection, and an exclusion area.

[0064] Next, in S13, the print control unit 420 determines whether the operation mode selected by the user is the regular printing mode (first operation mode) or the test printing mode (second operation mode). If the regular printing mode is selected, the process proceeds to S14. On the other hand, if the test printing mode is selected, the process proceeds to S16.

[0065] In S14, the print control unit 420 executes the actual print process. This print process executes the entire print job across multiple sheets, with each printed sheet inspected by the inspection unit 530, and reprinting is performed if a defect is detected. The flow of this actual print process will be described in more detail later with reference to FIG. 8.

[0066] In S16, the print control unit 420 acquires test printing-related settings. Test printing-related settings include, for example, the test printing range and the output destination of the inspection result data. Next, in S18, the print control unit 420 executes the test printing process. The test printing process is a partial test of a print job that spans multiple sheets, and each printed sheet is inspected by the inspection unit 530, but reprinting is not performed even if a defect is detected. A more detailed flow of the test printing process here will be described later using FIG. 9.

[0067] When the test printing process is complete, the user modifies the print job settings and inspection-related settings as necessary, and instructs the inspection system 1 to print in the actual printing mode. When the actual printing process is complete, a complete set of printed materials is provided to the user.

[0068] (2) Printing process Fig. 8 is a flowchart showing an example of the flow of a regular printing process involving reprinting that may be executed in S14 of Fig. 7. The regular printing process of Fig. 8 is executed by the image forming apparatus 200 and the inspection unit 530 under the control of the print control unit 420.

[0069] First, in S101 , the image forming apparatus 200 prints an image of one page on a sheet based on input image data, and outputs the printed sheet to the inspection apparatus 500 .

[0070] Next, in S102, the inspection unit 530 inspects the printed sheet received from the image forming apparatus 200. For example, the inspection unit 530 acquires scanned image data generated by scanning the printed sheet and performs image inspection based on a comparison between the scanned image and a reference image acquired in advance. The inspection unit 530 also performs character string inspection by searching for a specific character string within a character string inspection area in accordance with the inspection-related settings. The inspection unit 530 also performs code inspection by searching for a specific code within a code inspection area in accordance with the inspection-related settings. The inspection unit 530 outputs the inspection results to the print control unit 420.

[0071] Subsequent processing branches depending on whether or not defects were detected as a result of the inspection in S103. If no defects were detected on the printed sheet, processing proceeds to S104. On the other hand, if defects were detected on the printed sheet, processing proceeds to S106.

[0072] In S104, the print control unit 420 sets a variable N R Reset the variable N to zero. R The initial value of is zero. If no defects are detected, that is, if the printed sheet is determined to be normal, it is discharged to the discharge destination indicated by the basic settings. Next, in S105, the print control unit 420 determines whether the next page remains to be printed. If the next page remains to be printed, the process returns to S101, the image of the next page is printed on a new sheet, and the printed sheet is inspected in S102. If the next page does not remain to be printed, the process proceeds to S110.

[0073] In S106, the print control unit 420 sets a variable N R Determine whether variable N has reached a predetermined upper limit. R If the upper limit has not been reached, in S107, the print control unit 420 causes the image forming apparatus 200 to reprint the image corresponding to the defective sheet. The defective sheet is discharged to the purge tray 620. Next, in S108, the print control unit 420 R Then, the process returns to S102, and the printed sheet output from the image forming apparatus 200 is re-inspected by the inspection unit 530. R If the upper limit has already been reached, the print control unit 420 stops the execution of the print job in S109, and the process then proceeds to S110.

[0074] In S110, the print control unit 420 outputs the job execution results, including the inspection results of the printed sheets of each page, by, for example, writing them to a data file or displaying them on the screen.

[0075] (3) Test printing process Fig. 9 is a flowchart showing an example of the flow of a test printing process that does not involve reprinting, which may be executed in S18 of Fig. 7. The test printing process of Fig. 9 is executed by the image forming apparatus 200 and the inspection unit 530 under the control of the print control unit 420.

[0076] First, in S121, the image forming apparatus 200 prints an image of one page on a sheet based on input image data, and outputs the printed sheet to the inspection apparatus 500.

[0077] Next, in S122, the inspection unit 530 inspects the printed sheet received from the image forming apparatus 200. For example, the inspection unit 530 acquires scanned image data generated by scanning the printed sheet and performs image inspection based on a comparison between the scanned image and a reference image acquired in advance. The inspection unit 530 also performs character string inspection by searching for a specific character string within a character string inspection area in accordance with the inspection-related settings. The inspection unit 530 also performs code inspection by searching for a specific code within a code inspection area in accordance with the inspection-related settings. The inspection unit 530 outputs the inspection results to the print control unit 420.

[0078] Subsequent processing branches depending on whether or not defects were detected as a result of the inspection in S123. If no defects were detected on the printed sheet, processing proceeds to S125. On the other hand, if defects were detected on the printed sheet, processing proceeds to S126.

[0079] In S125, the print control unit 420 determines whether the next page remains to be printed. If the next page remains to be printed, the process returns to S121, the image of the next page is printed on a new sheet, and the printed sheet is inspected in S122. If the next page does not remain to be printed or the test printing range is limited to the first sheet, the process proceeds to S130.

[0080] In S126, the print control unit 420 determines whether the detected defect is a second type defect, i.e., a character string or code defect. If the detected defect is a first type defect and not a second type defect, the test print continues, and processing proceeds to S125. If the detected defect is a second type defect, processing proceeds to S127. In S127, the print control unit 420 stops execution of the print job. Then, processing proceeds to S130.

[0081] In S130, the print control unit 420 outputs the inspection results of the printed sheets for each page, for example, by writing them to a data file or displaying them on the screen.

[0082] (4) Print Control Process - Modified Example Fig. 10 is a flowchart showing an example of the flow of a print control process according to one variation. Unlike the example of Fig. 7, this variation allows the user to set whether or not to reprint an image corresponding to a defective sheet in the test print mode. The print control process of Fig. 10 is started in response to the user operating the test print button 118 or the start print button 119 on the print setting screen 110 of Fig. 4, for example.

[0083] S11 to S16 are the same processing steps as those explained using FIG. 7, and therefore their explanation will be omitted here.

[0084] After the user selects the test printing mode (second operating mode) and test printing-related settings are acquired in S16, the print control unit 420 determines in S17 whether the user settings indicate that the image corresponding to the defective sheet should be reprinted.

[0085] If the user settings indicate that the image corresponding to the defective sheet should not be reprinted, then in S18 the print control unit 420 executes the test print process described in detail with reference to FIG.

[0086] If the user settings indicate that the image corresponding to the defective sheet should be reprinted, in S19 the print control unit 420 executes a test print process that involves reprinting. The flow of the test print process here may be the same as the flow of the actual print process described with reference to Figure 8. However, the range of sheets to be printed is only a portion of the sheets, rather than all of the sheets determined by the number of copies to be printed in the basic settings and the number of pages of the input image data.

[0087] When the test printing process is complete, the user modifies the print job settings and inspection-related settings as necessary, and instructs the inspection system 1 to print in the actual printing mode. When the actual printing process is complete, a complete set of printed materials is provided to the user.

[0088] <8. Summary> Various embodiments, examples, and modifications of the technology according to the present disclosure have been described above using FIGS. 1 to 10 . In the above-described embodiments, in an inspection system, an image forming unit prints an image on a sheet, and an inspection unit inspects the printed sheet. A control unit of the inspection system controls the image forming unit to operate in an operation mode selected by a user from among a first operation mode in which the entire print job spanning multiple sheets is executed, and a second operation mode in which a partial print job is attempted. The inspection unit inspects printed sheets output from the image forming unit in both the first operation mode and the second operation mode. In the first operation mode, the control unit causes the image forming unit to reprint an image corresponding to a printed sheet for which a defect has been detected as a result of the inspection, while in the second operation mode, the control unit does not cause the image forming unit to reprint an image corresponding to a printed sheet for which a defect has been detected as a result of the inspection. This prevents waste of consumables such as sheets and toner and unnecessary increases in work hours during partial attempts of a print job, which often result in defects being detected due to inappropriate user settings.

[0089] In the above-described embodiment, the inspection unit outputs inspection result data indicating the results of the inspection performed on the printed sheets output from the image forming unit in both the first and second operating modes. Therefore, the user can check the data to see if there are any problems with the printouts output in the trial printout without relying solely on visual inspection, and can fully identify areas for improvement, such as reviewing settings. As a result, the possibility of defects occurring in the actual printing is reduced, and printing of a large number of pages or copies can be efficiently carried out.

[0090] <9. Other embodiments> The above-described embodiment can also be realized in the form of a process in which a program for realizing one or more functions is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program, or by a circuit (e.g., ASIC) that realizes one or more functions.

[0091] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0092] 1: inspection system, 100: operation unit, 200: image forming apparatus, 300Y, 300M, 300C, 300K: image forming units, 400: control device, 420: print control unit, 500: inspection apparatus, 505a, 505b: reading units, 530: inspection unit

Claims

1. an image forming unit that forms an image on a sheet; an inspection unit that inspects the sheet on which the image is formed; a control unit that controls the image forming unit to form images on sheets in a first operation mode in which a print job for forming images on a plurality of sheets is executed in its entirety, or in a second operation mode in which the print job is partially executed; Including, the inspection unit inspects the sheet on which the image is formed by the image forming unit in both the first operation mode and the second operation mode; The control unit In the first operation mode, when a defect is detected as a result of the inspection, an image corresponding to the sheet on which the defect is detected is formed again in the image forming unit; In the second operation mode, when a defect is detected as a result of the inspection, the image forming unit is not caused to form an image corresponding to the sheet on which the defect is detected again. Inspection system.

2. The inspection system according to claim 1 , wherein the inspection unit outputs inspection result data indicating the results of the inspection performed on the sheet on which an image is formed by the image forming unit in both the first operation mode and the second operation mode.

3. The inspection system includes: a reading unit that reads the sheet and generates a read image; further comprising The defects detectable by the inspection unit include: A first type of defect based on a mismatch between the scanned image and a reference image acquired in advance; and a second type of defect based on non-detection of a specific element in a partial area set by a user in the scanned image; The inspection system of claim 1 , comprising:

4. The specific elements are: Character strings recognized by optical character recognition, and Code in which information is encoded, The inspection system of claim 3 , comprising at least one of:

5. The inspection system described in claim 3, wherein when there are two or more sheets to be output by the image forming unit in the second operating mode, and a defect of the second type is detected as a result of inspecting a certain sheet, the control unit causes the image forming unit to stop forming images on subsequent sheets.

6. and when the image forming unit is to output two or more sheets in the second operation mode and the first type defect is detected as a result of the inspection of a certain sheet, the control unit causes the image forming unit to continue forming images on subsequent sheets. The inspection system of claim 5 .

7. The inspection system described in claim 5, wherein when the image forming unit has two or more sheets to output in the first operating mode and the defect is detected as a result of inspecting a certain sheet, the control unit causes the image forming unit to form an image corresponding to that sheet again, and then causes the image forming unit to continue forming images on subsequent sheets.

8. 2. The inspection system of claim 1, wherein the control unit does not cause the image forming unit to re-form the image corresponding to the sheet on which the defect was detected when a user setting indicates that the image corresponding to the sheet on which the defect was detected should not be re-formed in the second operating mode.

9. the inspection unit re-inspects the sheet output from the image forming unit as a result of the re-image formation, the control unit, in the second operation mode, when the number of times the same image has been formed by the image forming unit in accordance with the user setting reaches an upper limit, does not cause the image forming unit to form the image again. The inspection system of claim 8 .

10. The inspection system of claim 9 , wherein the upper limit is user-configurable.

11. 10. The inspection system of claim 9, wherein the upper limit imposed on the number of re-imagings in the second mode of operation is different from the upper limit imposed on the number of re-imagings in the first mode of operation.

Images