Image forming apparatus

Abstract

The invention provides an image forming apparatus. The purpose of the present invention is to generalize a line sensor for determining the quality of an output image in a plurality of models. The plurality of line sensors are arranged in a width direction intersecting a sheet conveying direction in a state in which positions in the width direction partially overlap each other, and each of the plurality of line sensors reads images of a plurality of partial regions, each of the plurality of partial regions being a part of a sheet passing region in the width direction. And each includes a non-overlapping region that does not overlap with the adjacent region and an overlapping region that overlaps with the adjacent region. The image determination unit determines whether or not data of each of the plurality of read images obtained by the plurality of line sensors satisfies permission conditions based on each of a plurality of pieces of reference image data. When it is determined that any one of the data of the plurality of read images does not satisfy the permission condition, the error processing unit executes predetermined error processing.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus capable of judging the quality of an image formed on a sheet. Background Art

[0002] The image forming apparatus includes a printing device for forming an image on a sheet. In addition, it is known that the image forming apparatus reads an output image formed on the sheet and determines whether the output image has an abnormality based on the read image.

[0003] However, the output image formed on the sheet is read by a line sensor. Generally, the line sensor is used with a length corresponding to the maximum width of the sheet that can be used.

[0004] When the line sensor having different lengths is used for each model having different maximum widths of the sheet, it is necessary to manage a plurality of types of the line sensors. On the other hand, it is desirable to make components common among a plurality of models. Summary of the invention

[0005] An object of the present invention is to provide an image forming apparatus capable of using a common line sensor for determining the quality of an output image in a plurality of models.

[0006] An image forming device according to one aspect of the present invention includes a printing device, a plurality of line sensors, an image determination unit, and an error processing unit. The printing device forms an image on a sheet conveyed along a conveying path. The plurality of line sensors are arranged downstream of the printing device in a sheet conveying direction in a width direction intersecting the sheet conveying direction in a state where the positions of the width direction are partially overlapped, and read images of a plurality of partial areas from the sheet, respectively. The plurality of partial areas are parts of the sheet passing area in the width direction, and respectively include non-overlapping areas that do not overlap with adjacent areas and overlapping areas that overlap with adjacent areas. The image determination unit determines whether the data of each of the plurality of read images obtained by the plurality of line sensors satisfies the respective permissible conditions based on the plurality of reference image data representing the images of the plurality of partial areas. When it is determined that any one of the data of the plurality of read images does not satisfy the permissible conditions, the error processing unit performs a predetermined error processing.

[0007] According to the present invention, it is possible to provide an image forming apparatus in which a line sensor used for determining the quality of an output image can be commonly used in a plurality of models.

[0008] This specification is presented in a simplified form, with appropriate reference to the accompanying drawings, to summarize the concepts described in the following detailed description. This specification is not intended to limit the important features and essential features of the subject matter described in the claims, nor is it intended to limit the scope of the subject matter described in the claims. In addition, the subject matter described in the claims is not limited to implementations that solve some or all of the disadvantages described in any part of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural diagram of the image forming apparatus according to the first embodiment.

[0010] Figure 2 This is a block diagram showing the configuration of a control device in the image forming apparatus according to the first embodiment.

[0011] Figure 3 This is a diagram showing an example of an arrangement state of a plurality of line sensors in the image forming apparatus according to the first embodiment.

[0012] Figure 4 This is a flowchart showing an example of the procedure of the image inspection process in the image forming apparatus according to the first embodiment.

[0013] Figure 5 This is a flowchart showing an example of the procedure of the first error process which is a part of the image inspection process in the image forming apparatus of the first embodiment.

[0014] Figure 6 This is a flowchart showing an example of the procedure of the second error process which is a part of the image inspection process in the image forming apparatus of the first embodiment.

[0015] Figure 7 This is a diagram showing an example of an arrangement state of a plurality of line sensors in the image forming apparatus according to the second embodiment. DETAILED DESCRIPTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the following embodiment is an example of a specific embodiment of the present invention and does not limit the technical scope of the present invention.

[0017] [First Embodiment: Configuration of Image Forming Apparatus 10] The image forming apparatus 10 of the first embodiment includes a sheet storage unit 1 , a sheet conveying device 2 , and a printing device 5 (see Figure 1 ).

[0018] Furthermore, the image forming apparatus 10 includes a human-machine interface device 800 and a control device 8 . The control device 8 controls the sheet conveying device 2 and the printing device 5 .

[0019] The sheet conveying device 2 conveys the sheets 9 accommodated in the sheet accommodating portion 1 one by one toward the conveying path 200 . Also, the sheet conveying device 2 conveys the sheets 9 along the conveying path 200 .

[0020] In the present embodiment, the sheet conveying device 2 includes a primary conveying device 21 , a belt conveying device 22 , and a secondary conveying device 23 .

[0021] The primary transport device 21 includes a sheet feeding mechanism 211 and a plurality of primary transport roller pairs 212 .

[0022] The sheet feeding mechanism 211 delivers the sheet 9 from the sheet storage unit 1 to the conveyance path 200 . The primary conveyance roller pair 212 conveys the sheet 9 along the conveyance path 200 , and further delivers the sheet 9 to the belt conveyance device 22 .

[0023] The belt conveyor 22 receives the conveyance of the sheet 9 from the primary conveyor 21 . The belt conveyor 22 conveys the sheet 9 along the conveyance path 200 , and further sends the sheet 9 to the secondary conveyor 23 .

[0024] The belt conveyor 22 includes a conveyor belt 221 and a plurality of support rollers 32. The belt conveyor 22 includes a motor (not shown) for rotating one of the plurality of support rollers 32.

[0025] The conveyor belt 221 is an endless belt member. The conveyor belt 221 is rotatably supported by a plurality of support rollers 32. When one of the plurality of support rollers 32 rotates, the conveyor belt 221 rotates.

[0026] The belt conveyor 22 conveys the sheet 9 sent out by the primary conveyor 21 onto the conveyor 221 along the upper surface of the conveyor 221. The belt conveyor 22 sends the sheet 9 from the upper surface of the conveyor 221 to the secondary conveyor 23. The area along the upper surface of the conveyor 221 is a part of the conveying path 200.

[0027] The secondary conveying device 23 receives the conveyance of the sheet 9 from the belt conveying device 22. The secondary conveying device 23 conveys the sheet 9 along the conveying path 200 and sends the sheet 9 from the conveying path 200 to a rear stage (not shown). For example, the rear stage is a discharge tray, a post-processing device, or a relay conveying device.

[0028] The printing device 5 executes a printing process that forms an image on the sheet 9 conveyed along the conveyance path 200 .

[0029] In this embodiment, the printing device 5 forms an image on the sheet 9 conveyed by the belt conveyor 22. Figure 1In the example shown, the printing device 5 performs the printing process in an inkjet manner.

[0030] exist Figure 1 In the illustrated example, the printing device 5 includes a plurality of ink ejection units 51 and a plurality of ink supply sections 52 corresponding to a plurality of colors, respectively.

[0031] The plurality of ink supply units 52 respectively supply inks of different colors to the plurality of ink ejecting units 51. The plurality of ink ejecting units 51 eject inks toward the sheet 9 to thereby form an image on the sheet 9.

[0032] In addition, the printing device 5 may be a device that executes the printing process in a method other than the inkjet method such as an electrophotographic method, for example.

[0033] [Human-machine interface device 800] The human-machine interface device 800 includes an operating device 801 and a display device 802 .

[0034] The operation device 801 is a device that detects a human operation and includes, for example, one or both of a touch panel and an operation button.

[0035] The display device 802 is a device that displays various information and is, for example, a panel display device such as a liquid crystal display panel.

[0036] [Control device 8] The control device 8 includes a CPU (Central Processing Unit) 81 , a RAM (Random Access Memory) 82 , an auxiliary storage device 83 , a signal interface 84 , a communication device 85 , and the like.

[0037] The auxiliary storage device 83 is a non-volatile storage device that can be read by a computer. The auxiliary storage device 83 can store and update computer programs and various data. For example, one or both of a flash memory and a hard disk drive are used as the auxiliary storage device 83.

[0038] The signal interface 84 converts signals output by various sensors into digital data, and transmits the converted digital data to the CPU 81. In addition, the signal interface 84 converts control instructions output by the CPU 81 into control signals, and transmits the control signals to the device of the control object.

[0039] The communication device 85 performs communication with other devices such as the host device 7. The CPU 81 communicates with the other devices through the communication device 85. The host device 7 is an information processing device such as a personal computer.

[0040] The host device 7 includes a human-machine interface device 70 including an operation unit 71 and a display unit 72 (see Figure 2 ). For example, the operation unit 71 includes one or more of a touch panel, a keyboard, and a mouse. The display unit 72 is a liquid crystal display or the like.

[0041] The CPU 81 is a processor that executes various data processing and control by executing the computer program. The control device 8 including the CPU 81 controls the sheet conveying device 2, the printing device 5, and the like.

[0042] The RAM 82 is a computer-readable volatile storage device and mainly stores the computer programs executed by the CPU 81 and data output and referenced during the CPU 81 executing various processes.

[0043] The CPU 81 includes a plurality of processing modules realized by executing the computer program, including a main processing unit 8a and a print control unit 8b.

[0044] The main processing unit 8a executes processing to start various processes in response to occurrence of various processing events, such as operation events and reception events.

[0045] The operation event is an event in which an operation of various processing requests is detected by the operation device 801. The reception event is an event in which an instruction of various processing requests is received by the communication device 85. The processing request includes a print request requesting execution of the print process.

[0046] The print control unit 8 b controls the sheet conveying device 2 and the printing device 5 . The print control unit 8 b controls conveyance of the sheet 9 by controlling the sheet conveying device 2 .

[0047] Furthermore, the print control unit 8 b causes the printing device 5 to execute the above-described printing process in synchronization with the conveyance of the sheet 9 by the sheet conveyance device 2 .

[0048] For example, when receiving the print request via the communication device 85 , the print control unit 8 b causes the sheet conveying device 2 to convey the sheet 9 and causes the printer 5 to execute the print process.

[0049] The image forming apparatus 10 can execute an image inspection process described below. The image inspection process is a process of reading an output image formed on the sheet 9 and determining whether or not there is an abnormality in the output image based on the read image.

[0050] Then, the output image formed on the sheet 9 is read by a line sensor. Generally, the line sensor having a length corresponding to the maximum width of the sheet 9 that can be used is used.

[0051] When the line sensor having different lengths is used for each model having different maximum widths of the sheet 9 , it is necessary to manage a plurality of types of the line sensors. On the other hand, it is desirable to make components common among a plurality of models.

[0052] The image forming apparatus 10 has a structure suitable for common use of the line sensor used in a plurality of models for determining the quality of an output image. This structure will be described below.

[0053] In the following description, the direction in which the sheet 9 is conveyed along the conveyance path 200 is referred to as a sheet conveyance direction D1 (see Figure 1 , Figure 3 ). In addition, the direction intersecting the sheet conveying direction D1 is referred to as the width direction D2 (refer to Figure 1 , Figure 3 ).

[0054] The width direction D2 corresponds to the main scanning direction in the printing device 5. The sheet conveying direction D1 is a direction along the sub-scanning direction of the printing device 5. In the present embodiment, the width direction D2 is a direction orthogonal to the sheet conveying direction D1.

[0055] The image forming apparatus 10 further includes a plurality of line sensors 3 (see Figure 1 , Figure 3 The plurality of line sensors 3 are arranged downstream of the printing device 5 in the sheet conveying direction D1. For example, each of the line sensors 3 is a CIS (Contact Image Sensor).

[0056] In this embodiment, the plurality of line sensors 3 are disposed opposite to the area between the belt conveyor 22 and the secondary conveyor 23 in the conveying path 200 (see Figure 1 ) The plurality of line sensors 3 are arranged at two locations offset from each other in the sheet conveying direction D1.

[0057] The plurality of line sensors 3 are arranged along the width direction D2 in a state where the positions of the respective line sensors 3 in the width direction D2 partially overlap each other (see Figure 3 ). The plurality of line sensors 3 read images of a plurality of partial areas A1, which are parts of the sheet passing area in the width direction D2, from the sheet 9 (see Figure 3 The sheet passing area is an area corresponding to the maximum width of the sheet 9 that can be used.

[0058] The plurality of partial regions A1 include non-overlapping regions A2 and overlapping regions A3. The non-overlapping regions A2 are regions in the plurality of partial regions A1 that do not overlap with adjacent regions. On the other hand, the overlapping regions A3 are regions in the plurality of partial regions A1 that overlap with adjacent regions.

[0059] The image forming apparatus 10 further includes a plurality of white reference members 4 (see Figure 1 , Figure 3 ) The white reference members 4 are members whose surfaces are white.

[0060] The plurality of line sensors 3 transmit data of a white image by executing a process of reading an image when the sheet 9 is not being conveyed. The white image is an image showing the surfaces of the plurality of white reference members 4 .

[0061] The data of the white image is used in a sensitivity adjustment process for adjusting the sensitivity of each line sensor 3. The description of the sensitivity adjustment process is omitted.

[0062] In this embodiment, the image forming apparatus 10 includes two white reference members 4 each supported in a rotatable roller shape. The two white reference members 4 are arranged at positions facing two locations in the sheet conveying direction D1 where a plurality of line sensors 3 are arranged (see Figure 1 , Figure 3 ).

[0063] Since the two white reference members 4 are in a roller shape, the sheet 9 is smoothly conveyed along the peripheral surfaces of the two white reference members 4 .

[0064] In this embodiment, the image forming device 10 includes two line sensors 3. In this case, the sheet passing area is divided into two non-overlapping areas A2 and one overlapping area A3. One of the two non-overlapping areas A2 and the overlapping area A3 is one of the two partial areas A1. The other of the two non-overlapping areas A2 and the overlapping area A3 is the other of the two partial areas A1.

[0065] The plurality of processing modules of the CPU 81 further include an image determination unit 8c and an error processing unit 8d (see Figure 2 ).

[0066] The image determination unit 8c executes image quality determination processing based on data of each of the plurality of read images obtained by the plurality of line sensors 3. The image quality determination processing is processing for determining whether the data of each of the plurality of read images satisfies the permission conditions based on each of the plurality of reference image data.

[0067] The plurality of reference image data are data indicating images of the plurality of partial regions A1 in the image formed on the sheet 9. The plurality of reference image data are data indicating images of the plurality of partial regions A1 to be formed on the sheet 9, respectively.

[0068] When it is determined that any one of the plurality of data of the read images does not satisfy the permission condition, the error processing unit 8d executes a predetermined error process.

[0069] [Image inspection processing] Below, refer to Figure 4 The flowchart shown in the figure explains an example of the steps of the image checking process. The image checking process is executed by the print control unit 8b, the image determination unit 8c and the error processing unit 8d.

[0070] For example, the print control unit 8 b starts the image checking process every time the print process is executed on a preset reference number of sheets 9 .

[0071] Alternatively, the print control unit 8 b may start the image inspection process when an inspection request is input via the operating device 801 or the communication device 85 .

[0072] In the following description, S101, S102, ... represent identification codes of a plurality of steps in the image inspection process. In the image inspection process, the process of step S101 is first executed.

[0073] <Step S101> In step S101, the print control unit 8b causes the sheet conveying device 2 and the printer device 5 to execute a test print process for forming a test image G1 on the sheet 9 (see FIG. 10A ). Figure 3 ).

[0074] The test image G1 is a predetermined pattern image. The test image G1 is formed on all the non-overlapping areas A2 and the overlapping areas A3 of the sheet 9 (see Figure 3 ). The test image G1 is an example of an output image formed on the sheet 9 .

[0075] The sheet conveying device 2 allows the sheet 9 on which the test image G1 is formed to pass through a region facing the plurality of line sensors 3 .

[0076] After executing the process of step S101 , the print control unit 8 b shifts the process to step S102 .

[0077] <Step S102> In step S102 , the image determination unit 8 c causes the plurality of line sensors 3 to execute a process of reading the test image G1 when the sheet 9 passes through the region facing the plurality of line sensors 3 .

[0078] By executing the process of step S102, data of a plurality of read images corresponding to the images of the plurality of partial regions A1 in the test image G1 are obtained. In the present embodiment, data of two read images are obtained.

[0079] The image determination unit 8 c acquires the data of the two read images from the two line sensors 3 , and shifts the process to step S103 .

[0080] <Step S103> In step S103, the image determination unit 8c executes the image quality determination process based on the data of the plurality of read images obtained in step S102.

[0081] In the image quality determination process, the image determination unit 8c divides the data of each of the plurality of read images into first read image data and second read image data. The first read image data is data of the non-overlapping area A2 in each of the plurality of partial areas A1, and the second read image data is data of the overlapping area A3 in each of the plurality of partial areas A1.

[0082] Furthermore, the image determination unit 8 c determines the permission condition individually for each partial area A1 with respect to the first scanned image data and the second scanned image data.

[0083] For example, the permission condition includes conditions such as the permission range of the positional deviation of the plurality of element images included in the test image G1 and the permission range of the difference between the values ​​of the plurality of pixel data constituting each of the plurality of element images.

[0084] In this embodiment, the image determination unit 8c divides each of the plurality of reference image data into first reference image data corresponding to the non-overlapping area A2 and second reference image data corresponding to the overlapping area A3. Each of the plurality of reference image data may be divided into the first reference image data and the second reference image data in advance.

[0085] Furthermore, the image determination unit 8 c determines, for each partial area A1 , whether or not the first read image data satisfies the permission condition based on the first reference image data.

[0086] Furthermore, the image determination unit 8 c determines, for each partial area A1 , whether or not the second scanned image data satisfies the permission condition based on the second reference image data.

[0087] The image determination unit 8 c determines whether the non-overlapping area A2 and the overlapping area A3 in the plurality of partial areas A1 are in a normal state that satisfies the permission condition or an abnormal state that does not satisfy the permission condition.

[0088] After executing the process of step S103 , the image determination unit 8 c shifts the process to step S104 .

[0089] <Step S104> In step S104 , the image determination unit 8 c selects a process to be executed next, depending on whether or not there is a region determined to be abnormal in the image among the plurality of partial regions A1 .

[0090] If there is a region determined to be abnormal in the image among the plurality of partial regions A1, the image determination unit 8c shifts the process to step S105. On the other hand, if there is no region determined to be abnormal in the image among the plurality of partial regions A1, the image determination unit 8c ends the image quality determination process.

[0091] <Step S105> In step S105 , the image determination unit 8 c selects a process to be executed next, depending on whether a contradiction occurs in the determination result of the permission condition for the overlap area A3 .

[0092] The contradiction in the determination result of the permission condition is a situation where it is determined that only one of the data of two adjacent partial regions among the plurality of partial regions A1 does not satisfy the permission condition for the overlap region A3 common to the two adjacent partial regions.

[0093] A first example of a situation in which the determination result of the permission condition does not cause a contradiction is a situation in which it is determined that both of the data of the two adjacent partial regions do not satisfy the permission condition for the overlap area A3 common to the two adjacent partial regions.

[0094] A second example of a situation in which the determination result of the permission condition does not produce a contradiction is a situation in which it is determined that both of the data of the two adjacent partial regions satisfy the permission condition for the overlap area A3 common to the two adjacent partial regions. In the second example, it is determined that any one of the first read image data does not satisfy the permission condition.

[0095] If the determination result of the permission condition for the overlap area A3 does not conflict, the image determination unit 8c transfers the process to step S106. On the other hand, if the determination result of the permission condition for the overlap area A3 conflicts, the image determination unit 8c transfers the process to step S107.

[0096] That is, when it is determined that both of the data of two adjacent partial regions among the plurality of partial regions A1 do not satisfy the permission condition for the overlap region A3 common to the two adjacent partial regions, the process of step S106 is executed.

[0097] On the other hand, when it is determined that only one of the data of two adjacent partial regions among the plurality of partial regions A1 does not satisfy the permission condition for the overlap region A3 common to the two adjacent partial regions, the process of step S107 is executed.

[0098] <Step S106> In step S106, the error processing unit 8d executes a predetermined first error processing. A specific example of the first error processing will be described later. After executing the first error processing, the error processing unit 8d ends the image quality determination processing.

[0099] <Step S107> In step S107, the error processing unit 8d executes a second error processing different from the first error processing. A specific example of the second error processing will be described later. After executing the second error processing, the error processing unit 8d ends the image quality determination processing.

[0100] [First error handling] Next, refer to Figure 5 The flowchart shown in the figure explains an example of the steps of the first error processing.

[0101] In the following description, S201, S202, ... represent identification symbols of a plurality of steps in the first error processing. In the first error processing, the processing of step S201 is first performed.

[0102] <Step S201> In step S201, the error processing unit 8d prohibits new printing processing.

[0103] For example, when the image checking process is executed while the continuous printing process is being executed, the subsequent printing process is not executed until the prohibition of the printing process is released.

[0104] After executing the process of step S201, the error processing unit 8d transfers the process to step S202.

[0105] <Step S202> In step S202, the error processing unit 8d executes a first inquiry process. The first inquiry process includes a process of notifying that an abnormality in the image is detected.

[0106] Furthermore, the first inquiry process includes a process of inquiring as to whether to execute re-execution of the image checking process or to release inhibition of the printing process.

[0107] For example, the error processing unit 8 d executes the first inquiry process through the human-machine interface device 800 of the image forming apparatus 10 .

[0108] In addition, the error processing unit 8 d may send inquiry information to the host device 7 via the communication device 85 , thereby executing the first inquiry process via the human-machine interface device 70 of the host device 7 .

[0109] After confirming the notification information of the first inquiry process, the user performs an adjustment response selected from a plurality of adjustment options. For example, the plurality of adjustment options include an operation of causing the operating device 801 to cause the image forming apparatus 10 to execute various adjustment processes such as head cleaning or print density correction.

[0110] Furthermore, a number of the adjustment options include cleaning the sheet conveying device 2 or the conveying path 200 .

[0111] After executing the process of step S202, the error processing unit 8d transfers the process to step S203.

[0112] <Step S203> In step S203, the error processing unit 8d selects the next process according to whether a recheck instruction is input as a response to the first inquiry process. The recheck instruction is an instruction requesting re-execution of the image check process.

[0113] Usually, after performing the adjustment, the user performs an operation corresponding to the re-examination instruction on the human-machine interface device 800 of the image forming apparatus 10 or the human-machine interface device 70 of the host device 7 .

[0114] The error processing unit 8d shifts the process to step S204 when the re-examination instruction is not input, and shifts the process to step S205 when the re-examination instruction is input.

[0115] <Step S204> In step S204, the error processing unit 8d selects the next process according to whether a release instruction is input as a response to the first inquiry process. The release instruction is an instruction requesting release of prohibition of the printing process.

[0116] When the user visually determines that the image quality of the test image G1 is acceptable, the user performs an operation corresponding to the release instruction on the human-machine interface device 800 of the image forming apparatus 10 or the human-machine interface device 70 of the host device 7 .

[0117] The error processing unit 8d shifts the process to step S203 when the release instruction is not input, and shifts the process to step S206 when the release instruction is input.

[0118] <Step S205> In step S205, the error processing unit 8d starts the image checking process. Figure 4 The process after step S101 shown in the figure. The error processing unit 8d ends the first error processing when starting the image inspection process.

[0119] <Step S206> In step S206 , the error processing unit 8 d cancels the prohibition of the printing process, thereby causing the image forming apparatus 10 to shift to a state in which the printing process can be executed.

[0120] After executing the process of step S206, the error processing unit 8d ends the first error process.

[0121] [Second error handling] Next, refer to Figure 6 The flowchart shown in the figure explains an example of the steps of the second error processing.

[0122] In the following description, S301, S302, ... represent identification codes of a plurality of steps in the second error processing. In the second error processing, the processing of step S301 is first performed.

[0123] <Step S301> In step S301, the error processing unit 8d prohibits new printing processing in the same manner as in step S201.

[0124] After executing the process of step S301, the error processing unit 8d transfers the process to step S302.

[0125] <Step S302> In step S302, the error processing unit 8d executes a second inquiry process including a process of notifying that an abnormality in the image is detected and that a conflict occurs in the determination result of the permission condition.

[0126] Furthermore, the second inquiry process includes a process of inquiring whether to execute the image checking process again or to execute invalid sensor setting.

[0127] The invalid sensor setting sets one of the two adjacent line sensors corresponding to the overlapping area A3 where the conflict occurs as an invalid sensor.

[0128] The two adjacent line sensors are two line sensors corresponding to the overlapping area A3 where the conflict occurs among the plurality of line sensors 3. In other words, the two adjacent line sensors are two line sensors corresponding to the overlapping area A3 causing the second erroneous process among the plurality of line sensors 3.

[0129] When the conflict occurs with respect to the overlap area A3, there is a possibility that an abnormality occurs in one of the two adjacent line sensors. The user determines the states of the two adjacent line sensors after confirming the notification information based on the second inquiry process.

[0130] In the present embodiment, the image forming apparatus 10 includes two line sensors 3. In this case, the two line sensors 3 are the two adjacent line sensors.

[0131] For example, the error processing unit 8 d executes the second inquiry process through the human-machine interface device 800 of the image forming apparatus 10 .

[0132] Furthermore, the error processing unit 8d may transmit inquiry information to the host device via the communication device 85, thereby executing the second inquiry process via the display unit of the host device.

[0133] After confirming the notification information based on the second inquiry process, the user performs the adjustment response selected from the plurality of adjustment options.

[0134] After executing the process of step S302, the error processing unit 8d transfers the process to step S303.

[0135] <Step S303> In step S303, the error processing unit 8d selects the next process according to whether the re-examination instruction is input as a response to the second inquiry process, similarly to step S203.

[0136] Usually, after performing the adjustment, the user performs an operation corresponding to the re-examination instruction on the human-machine interface device 800 of the image forming apparatus 10 or the human-machine interface device 70 of the host device 7 .

[0137] The error processing unit 8d shifts the process to step S304 when the re-examination instruction is not input, and shifts the process to step S305 when the re-examination instruction is input.

[0138] <Step S304> In step S304, the error processing unit 8d selects the next process according to whether an invalid setting instruction is input as a response to the second inquiry process.

[0139] The invalidation setting instruction is an instruction for requesting that one of the two adjacent line sensors corresponding to the overlapping area A3 where the conflict occurs be set as an invalid sensor. Input of the invalidation setting instruction is an example of input of invalidation instruction information.

[0140] When determining that one of the two adjacent line sensors corresponding to the conflict with respect to the overlapping area A3 is abnormal, the user performs an operation corresponding to the invalidation setting instruction on the human-machine interface device 800 of the image forming apparatus 10 or the human-machine interface device 70 of the host device 7 .

[0141] The error processing unit 8d shifts the process to step S303 when the invalid setting instruction is not input, and shifts the process to step S306 when the invalid setting instruction is input.

[0142] <Step S305> In step S305, the error processing unit 8d starts the image checking process. Figure 4 The process after step S101 shown in the figure. The error processing unit 8d ends the second error processing when starting the image inspection process.

[0143] <Step S306> In step S306, the error processing unit 8d sets one of the two adjacent line sensors as the invalid sensor in accordance with the invalid setting instruction.

[0144] In the image quality determination process of step S103, the image determination unit 8c determines the permission condition (see Figure 4 ).

[0145] After executing the process of step S306, the error processing unit 8d transfers the process to step S307.

[0146] <Step S307> In step S307, the error processing unit 8d cancels the prohibition of the printing process, thereby causing the image forming apparatus 10 to shift to a state in which the printing process can be executed.

[0147] After executing the process of step S307, the error processing unit 8d ends the second error process.

[0148] By adopting the image forming apparatus 10 , the line sensor 3 used for determining the quality of an output image can be made common among a plurality of models.

[0149] Furthermore, by determining whether or not the above-mentioned contradiction exists in the overlapping area A3, it is possible to understand whether or not an abnormality has occurred in a part of the plurality of line sensors 3 .

[0150] Furthermore, by setting the invalid sensor, even when a part of the plurality of line sensors 3 has an abnormality, the image inspection process using the valid line sensor can be executed until the abnormal part is replaced.

[0151] [Second embodiment] Next, refer to Figure 7 An image forming apparatus 10A according to a second embodiment will be described. Figure 7 In, with Figure 3The same components as shown are denoted by the same reference numerals.

[0152] Hereinafter, differences between the image forming apparatus 10A and the image forming apparatus 10 will be described. The image forming apparatus 10A is different from the image forming apparatus 10 in that the image forming apparatus 10A includes three line sensors 3 .

[0153] In the image forming apparatus 10A, three line sensors 3 are arranged along the width direction D2 so that their positions in the width direction D2 partially overlap. The three line sensors 3 read images of three partial areas A1 that are part of the sheet passing area in the width direction D2 from the sheet 9 .

[0154] The three partial areas A1 include a non-overlapping area A2 and an overlapping area A3 , respectively. In the image forming apparatus 10A, the sheet passing area is divided into three non-overlapping areas A2 and two overlapping areas A3 .

[0155] In the image forming apparatus 10A, one of the two white reference members 4 is disposed to face two of the three line sensors 3 , and the other of the two white reference members 4 is disposed to face the remaining one of the three line sensors 3 .

[0156] In the image forming apparatus 10A, the print control unit 8b, the image determination unit 8c, and the error processing unit 8d also execute the image checking process (see Figures 4 to 6 ).

[0157] When the image forming apparatus 10A is used, the same effects as those of the image forming apparatus 10 are obtained.

[0158] [Application Examples] The image forming apparatus 10A may include four or more line sensors 3 .

[0159] The scope of the present invention is not limited to the above content, but is defined by the description of the claims, so it can be considered that the embodiments described in this specification are only illustrative, not limiting. Therefore, all changes that do not depart from the scope and limits of the claims, as well as contents that are equivalent to the scope and limits of the claims, are included in the scope of the claims.

Claims

1. An image forming device, It is characterized in that include: A printing device that forms an image on a sheet conveyed along a conveying path; A plurality of line sensors are arranged downstream of the printing device in a sheet conveying direction and along a width direction intersecting the sheet conveying direction in a state where their respective positions in the width direction partially overlap, and read images of a plurality of partial areas from the sheet, the plurality of partial areas being parts of a sheet passing area in the width direction and including a non-overlapping area that does not overlap with an adjacent area and an overlapping area that overlaps with the adjacent area; an image determination unit for determining whether data of each of a plurality of read images obtained by the plurality of line sensors satisfies respective permission conditions based on a plurality of reference image data representing images of the plurality of partial areas; as well as The error processing unit executes a predetermined error processing when it is determined that any one of the plurality of data of the read images does not satisfy the permission condition.

2. The image forming apparatus according to claim 1, It is characterized in that The image determination unit determines the permission condition separately for the data of the non-overlapping area and the data of the overlapping area of ​​each of the plurality of partial areas. When it is determined that both data of two adjacent partial regions among the plurality of partial regions do not satisfy the permission condition for the overlapping region common to the two adjacent partial regions, the error processing unit performs a first error processing, When it is determined that only one of the data of the two adjacent partial regions does not satisfy the permission condition for the overlapping region common to the two adjacent partial regions, the error processing unit executes a second error processing different from the first error processing.

3. The image forming apparatus according to claim 2, It is characterized in that The second error handling comprises: inquiring, through a human-machine interface device, a process of setting one of two adjacent line sensors corresponding to the overlapping region causing the second error process among the plurality of line sensors as an invalid sensor; and When disabling instruction information indicating setting of the disabling sensor is input through the human-machine interface device, one of the two adjacent line sensors is set as the disabling sensor according to the disabling instruction information, The image determination unit determines the permission condition only for data corresponding to valid line sensors that are not set as invalid sensors among the plurality of line sensors.

Images