Image forming device

Abstract

To provide an image formation apparatus which performs printing of an image by suppressing reduction in yield rate and reduction in productivity.SOLUTION: An image formation apparatus comprises: a printer 300 which generates a printed matter; a first reading unit 5051a which reads an image formed on the printed matter; a printing inspection device 500 which inspects the quality of the image formed on the printed matter on the basis of the image reading result by the first reading unit 5051a; and a controller 400 which receives input of the inspection content of the quality to cause the printing inspection device 500 to perform inspection on the basis of the inspection content. The controller 400 calculates the yield rate of the printed matter on the basis of the result of the inspection by the printing inspection device 500, performs notification that urges change in the inspection content when the calculated yield rate is reduced with respect to a prescribed target value, and causes the printing inspection device 500 to perform inspection of the quality with the changed inspection content without stopping a job according to the notification.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus having a print inspection function for inspecting the quality of an image printed on paper. [Background technology]

[0002] An image forming device prints an image on paper based on image data representing the image to be printed to generate a printed product. A print inspection device inspects whether the image printed on paper by the image forming device is formed as specified by the image data. The print inspection device uses image data as reference data and scan data obtained by reading the image printed on paper with a sensor such as a scanner as inspection image data, and compares the two sets of data. The print inspection device judges the printing quality of the printed product based on the degree of match between the reference data and the inspection image data.

[0003] When a print inspection device judges an image based on many inspection items, the time required for judgment increases. This may lead to a decrease in productivity in image formation. Patent Document 1 discloses an inspection device that automatically determines inspection items based on the time available for quality inspection and the inspection time for each of a plurality of inspection items. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-205693 A Summary of the Invention [Problem to be solved by the invention]

[0005] The inspection device of Patent Document 1 allows the operator to set the inspection items. However, an operator who is inexperienced in inspecting image quality may not be able to set the appropriate inspection items due to a lack of understanding of the importance of each inspection item. For example, an inexperienced operator may inspect the quality of a printout at a very strict level, even if the inspection level for the inspection item is not required to be strict. This may result in a decrease in the yield rate of the printout and waste of paper and toner. In addition, when changing the inspection items to improve the yield rate, the started print job is temporarily stopped before the inspection items are reset. This takes time to create the printout, resulting in a decrease in productivity.

[0006] SUMMARY OF THE PRESENT DISCLOSURE In view of the above problems, an object of the present invention is to provide an image forming apparatus that prints images while preventing a decrease in yield rate and productivity. [Means for solving the problem]

[0007] The image forming apparatus of the present invention includes a printing means for forming an image on a sheet of paper to generate a printed matter, a reading means for reading the image formed on the printed matter, and an inspection means for inspecting the quality of the image formed on the printed matter based on a result of reading the image by the reading means. A setting means for setting the inspection contents to be inspected by the inspection means; The inspection method Control and a control means, the control means being configured to the law of nature inspection Varies depending on the number of inspections A yield rate is calculated, and the calculated yield rate is Less than threshold case , set by the setting means A notice is given to prompt a change in the content of the inspection, Even if the inspection content is changed by the setting means, the operation of the printing means is continued without being stopped; Changed The above Inspection details In front Before the above inspection method Examination Investigate Continue It is characterized by: Effect of the Invention

[0008] According to the present invention, since it is possible to change the inspection items even during the processing of a job without stopping the job, it is possible to prevent a decrease in yield rate and a decrease in productivity. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the configuration of an image forming system. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] 13A and 13B are diagrams illustrating an example of an operation screen. [Diagram 5] 13A and 13B are diagrams illustrating an example of an operation screen. [Figure 6] 13A and 13B are diagrams illustrating an example of an operation screen. [Figure 7] 4 is a flowchart showing a printing process including a test printing process. [Figure 8] 4 is a flowchart showing a printing process including a test printing process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] 1 is a configuration diagram of an image forming system including a print inspection device of the present embodiment. The image forming system 1 includes an operation unit 200, a printer 300, a controller 400, a print inspection device 500, a stacker 600, and a finisher 700.

[0012] The operation unit 200 is a user interface equipped with an input interface and an output interface. The input interface is, for example, an input key, a touch panel, etc. The output interface is, for example, a display, a speaker, etc. The operation unit 200 transmits instructions and data input from the input interface to the controller 400. In addition, the operation unit 200 outputs information from the output interface in response to an instruction from the controller 400.

[0013] The controller 400 controls the operations of the printer 300, the print inspection device 500, the stacker 600, and the finisher 700 based on instructions and data input from the operation unit 200, or instructions and data acquired from an external device via a network. For example, when performing image formation, the controller 400 transmits an image formation instruction to the printer 300. Details of the controller 400 will be described later.

[0014] (Printer) The printer 300 of this embodiment is a color image forming apparatus that prints a color image on paper. The printer 300 includes image forming units Y, M, C, and K, an intermediate transfer body 306, a transfer unit 307, a fixing unit 308, paper feed cassettes 311 and 312, and a paper feed mechanism. The image forming unit Y forms an image of yellow (Y). The image forming unit M forms an image of magenta (M). The image forming unit C forms an image of cyan (C). The image forming unit K forms an image of black (K). The intermediate transfer body 306 transfers the images of each color formed by the image forming units Y, M, C, and K in a superimposed manner. The transfer unit 307 transfers the image carried on the intermediate transfer body 306 to paper. The fixing unit 308 fixes the image transferred to the paper to the paper.

[0015] Each of the image forming units Y, M, C, and K has the same configuration and forms images by the same operation. Here, the configuration of the image forming unit Y will be described, and descriptions of the configurations of the image forming units M, C, and K will be omitted.

[0016] The image forming unit Y includes a photosensitive drum 301Y, a charger 302Y, an exposure device 303Y, and a developing device 304Y. The photosensitive drum 301Y is a drum-shaped photosensitive body having a photosensitive layer on its surface. The photosensitive drum 301Y rotates around the drum axis in the direction of the arrow R during operation. The charging device 302Y uniformly charges the surface of the rotating photosensitive drum 301Y. The exposure device 303Y acquires image data representing a yellow image from the controller 400, and outputs a laser beam in accordance with the image data. The laser beam output from the exposure device 303Y scans the surface of the charged photosensitive drum 301Y in the drum axis direction. By scanning the surface of the rotating photosensitive drum 301Y with the laser beam, an electrostatic latent image corresponding to the yellow image data is formed on the surface of the photosensitive drum 301Y. The developing device 304Y contains a yellow developer (e.g., toner) and develops the electrostatic latent image formed on the photosensitive drum 301Y with the developer. As a result, a yellow image is formed on the surface of the photosensitive drum 301Y. The developing device 304Y is configured so that developer can be constantly replenished from a toner cartridge (not shown).

[0017] Similarly, a magenta image is formed on the photosensitive drum 301M of the image forming station M. A cyan image is formed on the photosensitive drum 301C of the image forming station C. A black image is formed on the photosensitive drum 301K of the image forming station K.

[0018] The intermediate transfer body 306 is an endless belt member, and rotates in a clockwise direction in the figure. The intermediate transfer body 306 is in contact with each of the photosensitive drums 301Y, 301M, 301C, and 301K. As the intermediate transfer body 306 rotates, images of each color are transferred from each of the photosensitive drums 301Y, 301M, 301C, and 301K in order to be superimposed on each other. As a result, a full-color image is formed on the intermediate transfer body 306. The intermediate transfer body 306 conveys the full-color image it carries to a transfer unit 307 by rotating.

[0019] Paper is stored in paper feed cassettes 311 and 312, and is transported from paper feed cassettes 311 and 312 to transfer unit 307 by a feeding mechanism. The paper is transported according to the timing at which the image carried on intermediate transfer body 306 is transported to transfer unit 307. Transfer unit 307 transfers the image from intermediate transfer body 306 to the paper. A cleaner 309 is disposed downstream of transfer unit 307 in the rotation direction of intermediate transfer body 306. Cleaner 309 removes developer remaining on intermediate transfer body 306 after transfer.

[0020] The paper onto which the image has been transferred is transported from transfer unit 307 to fixing unit 308. Fixing unit 308 includes a heater and a pressure roller. Fixing unit 308 melts and fixes the image onto the paper by heat from the heater and pressure from the pressure roller.

[0021] Downstream of the fixing unit 308 in the paper transport direction are provided transport paths 313, 314, 315, a double-sided transport path 316, and discharge rollers 317. The paper that has passed through the fixing unit 308 is once transported from transport path 313 to transport path 314. After the rear end of the paper passes through transport path 313, the transport direction is reversed and the paper is transported from transport path 315 to discharge rollers 317. Through this transport, the paper is discharged from the printer 300 by the discharge rollers 317 with the side on which the image has been formed facing downward (face down). The printed matter, which is the paper after the image has been formed and discharged from the printer 300 by the discharge rollers 317, is delivered to the print inspection device 500.

[0022] When double-sided printing is to be performed on the paper, the paper transported to transport path 314 has its rear end pass through transport path 313, and is then transported to double-sided transport path 316. The paper is transported again to transfer unit 307 via double-sided transport path 316. By passing through double-sided transport path 316, the side of the paper on which the image has been formed is inverted. The inverted side of the paper is subjected to image transfer processing by transfer unit 307 and fixing processing by fixing device 308, so that an image is formed on that side. The paper with images formed on both sides is discharged from printer 300 by discharge rollers 317 as a printed matter, and delivered to print inspection device 500.

[0023] (Print inspection equipment) The print inspection device 500 includes a conveying path 501, an inspection control unit 510, a first reading unit 5051a, and a second reading unit 5051b. The inspection control unit 510 controls the operation of the print inspection device 500 under the control of the controller 400. The inspection control unit 510 will be described in detail later. The first reading unit 5051a and the second reading unit 5051b are disposed in positions facing each other across the conveying path 501.

[0024] The first reading unit 5051a and the second reading unit 5051b read the printed image from the printed material transported on the transport path 501. The first reading unit 5051a and the second reading unit 5051b transmit the reading result of the printed material to the inspection control unit 510. The inspection control unit 510 performs a quality inspection of the image printed on the printed material based on the reading result of the printed material. Since the first reading unit 5051a and the second reading unit 5051b are arranged opposite each other via the transport path 501, the images printed on both sides of the printed material are read in one transport of the printed material. The printed material from which the images have been read is transported from the print inspection device 500 to the stacker 600.

[0025] (Stacker, Finisher) The stacker 600 includes a large-capacity tray 610 and a purge tray 620. The stacker 600 discharges printed materials to any one of the large-capacity tray 610, the finisher 700, or the purge tray 620 based on instructions from the controller 400 and the results of quality inspection by the inspection control unit 510.

[0026] The finisher 700 includes a printed matter transport section 710 including a plurality of transport rollers and a transport path, an upper discharge tray 701, a middle discharge tray 702, and a lower discharge tray 703. The printed matter transport section 710 includes switching mechanisms 711 and 712 for switching the discharge destination of the printed matter. The finisher 700 sequentially takes in the printed matter from the stacker 600, and discharges the printed matter to any one of the upper discharge tray 701, the middle discharge tray 702, and the lower discharge tray 703 in response to an instruction from the controller 400. The finisher 700 may also include a configuration for performing post-processing such as stapling to bind multiple printed matters together, bookbinding of the bound printed matters, and trimming of the bound printed matters.

[0027] (controller) 2 is a diagram illustrating the configuration of the controller 400. In addition to the printer 300, the print inspection device 500, and the operation unit 200, the controller 400 is connected to a storage 4100 and a power supply control unit 4500. The controller 400 includes a storage I / F 4318, an operation unit I / F 4306, a power supply control I / F 4308, an inspection unit I / F 4317, a printer communication I / F 4307, and a printer I / F 4316 as interfaces with each of these connected units. The controller 400 also includes a communication I / F 4305 for communicating with an external device via a network. The storage I / F 4318, the operation unit I / F 4306, the power supply control I / F 4308, the inspection unit I / F 4317, the printer communication I / F 4307, and the communication I / F 4305 are connected to a system bus 4319.

[0028] The controller 400 includes a central processing unit (CPU) 4301, a read only memory (ROM) 4302, and a random access memory (RAM) 4303. The CPU 4301 controls the operation of the image forming system 1 by executing a computer program stored in the ROM 4302. The RAM 4303 provides a working area for the CPU 4301 to execute processing. The RAM 4303 is also used as an image memory for temporarily storing image data and the like. The CPU 4301, the ROM 4302, and the RAM 4303 are also connected to a system bus 4319. A non-volatile RAM (NVRAM) 4304 and a timer 4309 are also connected to the system bus 4319. The NVRAM 4304 stores various control parameters. The timer 4309 holds the current time and monitors the passage of a set time.

[0029] The operation unit I / F 4306 controls communication with the operation unit 200. The operation unit I / F 4306 accepts inputs such as print jobs, commands, and print settings from the operation unit 200 to the controller 400, and transmits them to the CPU 4301. The operation unit I / F 4306 displays various screens and the status of the image forming system 1 on the operation unit 200 under the control of the CPU 4301. The printer communication I / F 4307 controls communication with the printer 300 under the control of the CPU 4301. The power supply control I / F 4308 instructs the power supply control unit 4500 to supply / stop various types of power under commands from the CPU 4301. The power supply control unit 4500 supplies power to the printer 300. The inspection unit I / F 4317 controls communication with the print inspection device 500 under the control of the CPU 4301. The storage I / F 4318 controls communication with the storage 4100 under the control of the CPU 4301. The storage 4100 is a large-capacity storage device such as a hard disk drive (HDD) or a solid state drive (SSD).

[0030] The communication I / F 4305 is connected to a network such as a LAN (Local Area Network) and performs communication control such as sending and receiving e-mails and inputting and outputting PDL data from external devices. The communication I / F 4305 also has an NVRAM (not shown) that holds various parameters related to communication control such as a MAC address.

[0031] The system bus 4319 is connected to an image bus 4311 via a bus I / F 4310. The bus I / F 4310 is a bridge that connects the system bus 4319 and an image bus 4311 for transferring image data to the printer 300. A printer I / F 4316, an image compression unit 4312, an image rotation unit 4313, and a RIP (Raster Image Processor) unit 4314 are connected to the image bus 4311.

[0032] An image compression unit 4312 performs compression and decompression processing for JPEG, JBIG, MMR, MH, etc. An image rotation unit 4313 performs image rotation processing. A RIP unit 4314 expands PDL code into a bitmap raster image. A printer I / F 4316 transmits image data to the printer 300. This image data is generated by the controller 400 performing image processing for the printer 300, such as correction for the printer 300 and resolution conversion, on image data for print output.

[0033] (Inspection Control Unit) 3 is a diagram illustrating the configuration of an inspection control unit 510 provided in the print inspection device 500. The inspection control unit 510 controls the operations of the first reading unit 5051a and the second reading unit 5051b. The inspection control unit 510 performs processes such as analyzing the reading results of the first reading unit 5051a and the second reading unit 5051b, controlling the operation of the print inspection device 500, and communicating with the controller 400.

[0034] The inspection control unit 510 includes a CPU 5001, a ROM 5002, a RAM 5003, a storage I / F 5004, a motor control unit 5009, a read image processing unit 5008, an image processing unit 5006, an RTC 5012, a host I / F 5007, and a sensor control unit 5010. Each unit is connected to a system bus 5005. The read image processing unit 5008 is connected to a first reading unit 5051a via a first reading I / F 5052a, and is connected to a second reading unit 5051b via a second reading I / F 5052b.

[0035] The host I / F 5007 controls communication with the inspection unit I / F 4317 of the controller 400. When the inspection control unit 510 and the controller 400 communicate with each other, data is transmitted and received between the host I / F 5007 and the inspection unit I / F 4317. For example, the host I / F 5007 acquires image data used in the image forming operation of the printer 300 from the controller 400. The image data is stored in, for example, the storage 5011.

[0036] The CPU 5001 controls the operation of the print inspection device 500 by executing a computer program stored in the ROM 5002. The RAM 5003 provides a working area for the CPU 5001 to execute processing. The storage I / F 5004 controls communication with a storage 5011 connected to the inspection control unit 510. The storage 5011 is a large-capacity storage device such as an HDD or SSD.

[0037] The read image processing unit 5008, under the control of the CPU 5001, acquires the read result of the image of the printed matter from the first reading unit 5051a via the first reading I / F 5052a. Also, under the control of the CPU 5001, the read image processing unit 5008 acquires the read result of the image of the printed matter from the second reading unit 5051b via the second reading I / F 5052b. Under the control of the CPU 5001, the read image processing unit 5008 performs magnification processing, gamma correction processing, etc. on the read result (read data) of the image of the printed matter acquired from the first reading unit 5051a and the second reading unit 5051b to generate read image data and store it in the RAM 5003. The first reading unit 5051a and the second reading unit 5051b are configured with a sensor array and are capable of reading the entire area of ​​the printed matter transported on the transport path 501. The first reading unit 5051a reads an image on a first side of a printed material, and the second reading unit 5051b reads an image on a second side of the printed material.

[0038] The first reading unit 5051a and the second reading unit 5051b are composed of a light emitting unit and a light receiving unit. The light emitting unit is composed of, for example, a white LED (Light Emitting Diode), and the light receiving unit is composed of, for example, a CMOS sensor with an RGB color filter. The light emitting unit irradiates light onto the printed material transported on the transport path 501 under the control of the CPU 5001. The light receiving unit receives the light reflected by the printed material by separating it into three color components of RGB using a color filter, and outputs read data as the light reception result (read result). The read data is transmitted to the read image processing unit 5008.

[0039] The motor control unit 5009 controls the operation of various motors provided in the print inspection device 500 under the control of the CPU 5001. The sensor control unit 5010 controls the operation of various sensors provided in the print inspection device 500 under the control of the CPU 5001, and notifies the CPU 5001 of the detection results of the sensors. The image processing unit 5006 compares the image data stored in the storage 5011 (hereinafter referred to as "reference image data") with the read image data stored in the RAM 5003 under the control of the CPU 5001 to inspect the quality of the print. The reference image data is generated from the read result by reading a reference image in advance before the quality inspection is performed, and is stored in the storage 5011. Alternatively, the reference image data may be image data used in the image forming operation of the printer 300. For example, the luminance value or density value for each color of each pixel derived from the image data used in the image forming operation is used as the reference image data. The image processing unit 5006 performs position correction processing of the reference image data and the read image data at the time of comparison. The RTC 5012 is a real-time clock, and holds the current time with high accuracy.

[0040] (Test setting process) 4 to 6 are exemplary views of operation screens displayed on the display of the operation unit 200 during inspection printing processing, which is printing processing involving quality inspection of printed matter. The operator uses the operation screens displayed on the display to set quality inspection items using the operation unit 200 and instructs execution of the inspection printing process.

[0041] FIG. 4(a) is a setting screen for printing processing, and it is possible to set whether or not to perform quality inspection. The operator can use this setting screen to select the printing color (color / black and white), the paper type, and the destination of the printed matter. The destination of the printed matter is set using the "paper output tray setting" button 104. The operator can set the quality inspection of the printed matter by pressing the "start printing (with inspection)" button 101. Pressing the "start printing (with inspection)" button 101 displays the setting screen for the inspection items in FIG. 4(b) on the display of the operation unit 200. Note that when the "start printing (without inspection)" button 102 is pressed, the formation of the printed matter is started without performing quality inspection. When the "cancel" button 103 is pressed, the setting is canceled and a predetermined initial screen is displayed on the display of the operation unit 200.

[0042] The inspection item setting screen in FIG. 4(b) allows the user to set the contents of the quality inspection, such as the quality inspection item, inspection level, and inspection area.

[0043] In the inspection area setting section 401, an image of the reference image data is displayed as a reference image. When an area to be inspected is set in the inspection area setting section 401 with respect to the reference image, this inspection area is indicated by a dashed line. An inspection area setting button 404 is provided in the inspection area setting section 401. While the inspection area setting button 404 is selected, the operator can set the inspection area from the reference image. For example, the operator operates the display screen area of ​​the inspection area setting section 401 with a finger or a stylus pen, or operates a cursor on the screen to select an area, thereby setting the inspection area. Note that if the operator can set the inspection area, the setting method is not specified.

[0044] The inspection item setting section 402 enables selection of items to be inspected in the inspection area set in the inspection area setting section 401. A check box is provided for each item in the inspection item setting section 402, and the inspection item is set by checking the check box. In FIG. 4(b), image stains (dots, streaks) and image defects can be set as inspection items.

[0045] The inspection level setting unit 403 enables selection of an inspection level for the inspection item set in the inspection item setting unit 402. The inspection level setting unit 403 has a number and a check box for each inspection item, and the inspection level is set by checking the check box.

[0046] The allowable yield rate input area 407 is an input area for the yield rate that is allowable during quality inspection of printed matter. If the yield rate falls below the allowable yield rate, a message to that effect is displayed in the message display area 412. The yield rate is displayed in the yield rate display area 411. The yield rate is the ratio of the number of printed matter determined to be of good quality to the number of printed matter that have undergone quality inspection.

[0047] The required number of sheets setting section 408 is an input area for setting the number of required printed sheets. The number of printed sheets determined to be of good quality as a result of the quality inspection is displayed in the number of OK sheets display section 409. The number of OK sheets display section 409 displays the number of printed sheets determined to be good, with the required number of sheets as the denominator and the number of printed sheets determined to be good as the numerator. The number of printed sheets determined to be of poor quality as a result of the quality inspection is displayed in the number of NG sheets display section 410.

[0048] The "Decide" button 405 is a button for deciding the inspection contents such as the inspection area, inspection item, inspection level, acceptable yield rate, required number of sheets, etc. When the operator presses the "Decide" button 405, the inspection printing process begins. The "Decide" button 405 cannot be pressed until each item is input. The "Cancel" button 406 is a button for canceling the inspection contents. When the operator presses the "Cancel" button 406, the inspection contents are canceled, and the printing process setting screen of FIG. 4(a) is displayed on the display.

[0049] FIG. 5(a) illustrates an example of an inspection screen that is displayed on the display of the operation unit 200 while the inspection printing process is being performed after the "OK" button 405 in FIG. 4(b) is pressed. During the inspection printing process, the rest of the screen is grayed out, leaving only the OK number display unit 409, the NG number display unit 410, the yield rate display unit 411, and the message display unit 412, and the inspection contents cannot be changed. In addition, "Inspection in progress" is displayed at the top of the inspection screen. In order to change the inspection contents during the inspection printing process, a "Change Settings" button 413 is displayed in the grayed-out area. When the operator presses the "Change Settings" button 413, the inspection contents can be changed.

[0050] Fig. 5(b) shows an example of an inspection screen that is displayed on the display of the operation unit 200 when the yield rate falls below the allowable yield rate during the inspection printing process. When the yield rate falls below the allowable yield rate, a notification is displayed in the message display unit 412, urging the user to change the inspection content. Also, the grayed-out parts in Fig. 5(a) are cleared, making it possible to change the inspection content.

[0051] Fig. 6(a) shows an example of an inspection screen displayed on the display of the operation unit 200 during inspection printing processing after the inspection level and inspection area of ​​each inspection item have been changed from the inspection screen in Fig. 5(b). In Fig. 6(a), the inspection level has been lowered and the inspection area has been limited to improve the yield rate, compared to the settings in Fig. 5(b). Because the inspection content has been changed, a "Confirm" button 405 can be pressed to reflect the changes.

[0052] Fig. 6(b) shows an example of an inspection screen that is displayed on the display of the operation unit 200 while the inspection printing process is being performed after the "OK" button 405 is pressed in Fig. 6(a). The same parts as in Fig. 5(a) are grayed out. In Fig. 6(b), the yield rate during the inspection printing process exceeds the allowable yield rate, and no notification urging the user to change the inspection items is displayed in the message display unit 412.

[0053] (Inspection printing process) 7 and 8 are flowcharts showing printing processing including inspection printing processing. This processing is executed by the CPU 4301 of the controller 400. This processing is started when the operator presses the "Start printing (with inspection)" button 101 or the "Start printing (without inspection)" button 102 in FIG. 4(a).

[0054] The CPU 4301 checks whether a print job has been requested by pressing the "Start Print (with inspection)" button 101 or the "Start Print (without inspection)" button 102 (S501). If there is no request (S501: N), the CPU 4301 waits until a request is made. If there is a request (S501: Y), the CPU 4301 determines whether or not to perform a quality inspection of the printed matter (S502). The CPU 4301 makes this determination based on whether the "Start Print (with inspection)" button 101 or the "Start Print (without inspection)" button 102 has been pressed.

[0055] If the "Start Printing (No Inspection)" button 102 is pressed, the CPU 4301 determines that a quality inspection is not required (S502: N). In this case, the CPU 4301 causes the printer 300 to print an image that does not require a quality inspection on paper (S511). The CPU 4301 ejects the printout to the ejection tray set by the "Ejection Tray Setting" button 104 in FIG. 4(a) (S512). If a quality inspection is not performed, the print process ends with the ejection of the printout.

[0056] If the "Start Printing (with inspection)" button 101 is pressed, the CPU 4301 determines that a quality inspection is necessary (S502: Y). In this case, the CPU 4301 performs a process for setting the inspection items (S503). Fig. 8 shows the process for setting the inspection items.

[0057] In the process of setting the inspection items, the CPU 4301 first prints a reference image, which is a standard for quality inspection, on a sheet of paper using the printer 300 (S520). The CPU 4301 controls the inspection control unit 510 to read the reference image printed on the sheet of paper using the print inspection device 500 (S521). As a result, reference image data generated from the reading result of the reference image is stored in the storage 5011. The sheet of paper on which the reference image has been printed is discharged to the purge tray 620 (S522). Note that when image data used in the image forming operation of the printer 300 is used as the reference image data, the processes of S520 to S522 may be omitted.

[0058] After reading the reference image, the CPU 4301 displays the inspection item setting screen of FIG. 4B on the display of the operation unit 200 (S523). A message prompting the operator to input the inspection item is displayed in the message display section 412 of the inspection item setting screen. When the inspection item is input on the inspection item setting screen (S524: Y), the CPU 4301 makes the "OK" button 405 pressable (S525). When the "OK" button 405 is pressed (S526: Y), the CPU 4301 makes the setting of the inspection item on the inspection item setting screen unchangeable (grayed out) and displays the "Change Setting" button 413 (S527). That is, the CPU 4301 displays an inspection in progress screen as shown in FIG. 5A on the display. With the above, the inspection item setting process ends.

[0059] When the inspection item setting process is completed, the CPU 4301 causes the printer 300 to form an image on paper according to the print job to generate a printed matter (S504). The printed matter is transported from the printer 300 to the print inspection device 500. The CPU 4301 controls the inspection control unit 510 to read the image printed on the paper by the print inspection device 500 (S505). The read image is stored in the RAM 5003 as read image data. The CPU 4301 performs a quality inspection of the printed matter by comparing the reference image data stored in the storage 5011 with the read image data stored in the RAM 5003 under the conditions set in the inspection item setting process by the inspection control unit 510 (S506).

[0060] If the quality of the printed matter is judged to be good as a result of the quality inspection (S507: N), the CPU 4301 checks whether the inspection items have been reset during the print job (S513). If the inspection items have not been reset (S513: N), the CPU 4301 discharges the printed matter to the large-capacity tray 610 of the stacker 600 (S515). If the inspection items have been reset (S513: Y), the CPU 4301 discharges the printed matter to the paper output tray set by the "Paper Output Tray Setting" button 104 in FIG. 4A (S514). For example, if the yield rate at this point is below the allowable yield rate, the inspection items are reset during the print job. In this case, in order to distinguish the printed matter before and after the change of the inspection items, the printed matter is discharged to a paper output destination other than the large-capacity tray 610. The "Paper Output Tray Setting" button 104 can also be set to the large-capacity tray 610. If it is not necessary to distinguish the printed matter before and after the change of the inspection items, the large-capacity tray 610 may be set.

[0061] The CPU 4301 counts the number of printed sheets determined to be of good quality. When the counted number of printed sheets reaches the required number set in the required number setting unit 408 (S509: Y), the CPU 4301 clears the setting of the inspection items (S510) and ends the printing process.

[0062] If the quality inspection determines that the quality of the printed matter is poor (S507: Y), the CPU 4301 ejects the printed matter onto the purge tray 620 (S508). The CPU 4301 calculates the yield rate (S516). Note that the CPU 4301 also calculates the yield rate (S516) when the number of printed matter has not reached the required number set by the required number setting unit 408 (S509: N).

[0063] The CPU 4301 determines whether the calculated yield rate is below the allowable yield rate (S517). If the yield rate is above the allowable yield rate (S517: N), the CPU 4301 returns to the process of S504 and continues to print images on paper according to the print job. If the yield rate is below the allowable yield rate (S517: Y), the CPU 4301 displays an inspection screen as shown in FIG. 5B on the display. This inspection screen prompts the operator to change the inspection items, and enables the inspection items to be reset (S518, S519). If the inspection items are to be reset, the CPU 4301 performs the process of S524 and subsequent steps in FIG. 8, and returns to the process of S504 when the resetting is completed.

[0064] When the yield rate of the printed matter falls below the target value (acceptable yield rate), the image forming system 1 of this embodiment notifies the operator and prompts the operator to change the inspection contents, such as the inspection items, inspection level, and inspection area. The inspection contents can be changed even while the print job is being executed, without stopping the print job. By changing the inspection contents, the yield rate is improved above the target value, and waste of developer and paper is prevented. Furthermore, since there is no need to temporarily stop the print job, the image forming system 1 can prevent a decrease in the processing efficiency of the inspection printing process.

[0065] The image forming system 1 may temporarily stop the inspection printing process if the yield rate drops significantly from a predetermined target value. The image forming system 1 may also temporarily stop the inspection printing process if a large number of prints that are determined to be defective as a result of quality inspection are continuously produced. In these cases, a problem may have occurred in the printer 300. Therefore, in such cases, the image forming system 1 temporarily stops the inspection printing process and instructs the operator to inspect and clean the printer 300.

Claims

1. A printing means for forming an image on a sheet to generate a printed matter; a reading means for reading the image formed on the printed matter; an inspection means for inspecting the quality of the image formed on the printed matter based on a result of reading the image by the reading means; A setting means for setting the inspection contents to be inspected by the inspection means; A control means for controlling the inspection means, the control means calculates a yield rate which varies according to the number of sheets inspected by the inspection means, and when the calculated yield rate is smaller than a threshold value, issues a notice to prompt a change of the inspection contents set by the setting means, and even if the inspection contents are changed by the setting means, causes the operation of the printing means to continue without stopping, and causes the inspection means to continue the inspection with the changed inspection contents. Image forming device.

2. The printing apparatus further includes a plurality of output trays to which the printed matter is output, The control means discharges printed matter determined to be of good quality based on the inspection contents before the change and printed matter determined to be of good quality based on the inspection contents after the change to different discharge trays.

2. The image forming apparatus according to claim 1.

3. the control means discharges the printed matter determined to be of poor quality as a result of the inspection by the inspection means to a paper discharge tray different from a paper discharge tray to which the printed matter determined to be of good quality is discharged.

3. The image forming apparatus according to claim 2.

4. A stacker having a large capacity tray is further included, the control means ejects onto the large-capacity tray the printed matter that has been determined to be of good quality based on the inspection content before the change.

4. The image forming apparatus according to claim 2 or 3.

5. The control means displays a setting screen for inputting the test contents on a display and accepts the test contents set on the setting screen. The image forming apparatus according to any one of claims 1 to 4.

6. the control means is characterized in that, when the yield rate is equal to or higher than the threshold value, the control means does not allow the inspection content to be changed via the setting screen.

6. The image forming apparatus according to claim 5.

7. the control means enables the inspection content to be changed on the setting screen when the yield rate is smaller than the threshold value.

7. The image forming apparatus according to claim 5.

8. The control means causes the printing means to form a reference image on a sheet, causes the reading means to read the reference image from the sheet on which the reference image is formed, and generates reference image data to be used by the inspection means when performing the inspection based on a reading result of the reference image, and stores the generated reference image data in a storage means. The image forming apparatus according to any one of claims 1 to 7.

9. The printing means forms an image on the paper based on image data; The control means generates reference image data to be used when the inspection means inspects the quality of the image formed on the printed matter based on the image data, and stores the generated reference image data in a storage means. The image forming apparatus according to any one of claims 1 to 7.

10. The inspection means performs the inspection by comparing read image data based on a result of reading the image by the reading means with the reference image data.

10. The image forming apparatus according to claim 8.

Images