Image forming apparatus, print job execution method, and print job execution program

Abstract

To prevent unnecessary consumption of a recording medium.SOLUTION: An image forming apparatus comprises: a class inspection control unit 127 that inspects the class of a recording medium; an image inspection control unit 125 that inspects an image formed on the recording medium; a job acquisition unit 121 that acquires a print job including image data comprising a plurality of pages; an image forming unit that forms an image on the recording medium; and a job execution unit 123 that causes the image forming unit to form the image according to the print job. When the image inspection control unit 125 detects an image abnormality, the job execution unit 123 executes recovery processing of causing the image forming unit to form an image from a page on which the image abnormality is detected, and when the class inspection control unit 127 detects a class abnormality before the execution of the recovery processing, does not execute the recovery processing.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus, a print job execution method, and a print job execution program, and more particularly to an image forming apparatus capable of executing recovery processing, a print job execution method executed by the image forming apparatus, and a print job execution program that causes a computer to execute the print job execution method. [Background technology]

[0002] There is known an image forming apparatus that has a function of inspecting whether an image is normally formed on a recording medium by the image forming apparatus, and if it is determined that an image is not normally formed on the recording medium, performs a recovery process in which the image formed on the recording medium on which the abnormal image was formed is formed onto another recording medium.

[0003] For example, Japanese Patent Application Laid-Open No. 2023-48841 describes an image forming device that can perform inline inspection, in which a sheet on which an image is formed by a printing device is transported to an inspection device for inspection, and offline inspection, in which a sheet is transported to an inspection device for inspection without image formation by a printing device, and that allows the setting of recovery processing in inline inspection and prohibits the setting of recovery processing in offline inspection.

[0004] On the other hand, there are multiple types of recording media on which images are formed, and the type of recording media on which images are to be formed is set by the user. It is not desirable to form an image on a recording medium of a type different from the type set by the user.

[0005] In the image forming apparatus described in JP 2023-48841 A, recovery processing is performed during in-line inspection, but it does not determine whether the type of recording medium on which the image is to be formed matches the type set by the user. Therefore, if the type of recording medium on which the image is to be formed by the recovery processing is different from the type set by the user, the image will be formed on a recording medium of a different type than the type set by the user. This results in the problem of recording media on which the image is formed being wasted due to the recovery processing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-48841 Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that can suppress the wasteful consumption of recording media.

[0008] Another object of the present invention is to provide a print job execution method that can prevent unnecessary consumption of recording media.

[0009] It is still another object of the present invention to provide a print job execution program that can reduce wasteful consumption of recording media. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, according to one aspect of the present invention, an image forming apparatus includes a type inspection unit that inspects the type of recording medium, an image inspection unit that inspects an image formed on the recording medium, a job acquisition unit that acquires a print job including image data consisting of multiple pages, an image forming unit that forms an image on the recording medium, and a job execution unit that causes the image forming unit to form an image in accordance with the print job, and when an image abnormality is detected by the image inspection unit, the job execution unit executes a recovery process that causes the image forming unit to form an image from the page in which the image abnormality was detected, and when a type abnormality is detected by the type inspection unit before executing the recovery process, the job execution unit does not execute the recovery process.

[0011] According to another aspect of the present invention, a print job execution method is a print job execution method executed in an image forming device equipped with an image forming unit that forms an image on a recording medium, and includes a type inspection step of inspecting the type of the recording medium, an image inspection step of inspecting the image formed on the recording medium, a job acquisition step of acquiring a print job including image data consisting of multiple pages, and a job execution step of causing the image forming unit to form an image in accordance with the print job, wherein the job execution step includes a step of executing a recovery process, if an image abnormality is detected in the image inspection step, causing the image forming unit to form an image from the page in which the image abnormality was detected, and a step of not executing the recovery process, if a type abnormality is detected in the type inspection step before executing the recovery process.

[0012] According to yet another aspect of the present invention, a print job execution program is a print job execution program executed by a computer that controls an image forming device equipped with an image forming unit that forms an image on a recording medium, and causes the computer to execute a type inspection step of inspecting the type of the recording medium, an image inspection step of inspecting the image formed on the recording medium, a job acquisition step of acquiring a print job including image data consisting of multiple pages, and a job execution step of causing the image forming unit to form an image in accordance with the print job, and the job execution step includes a step of executing a recovery process, if an image abnormality is detected in the image inspection step, causing the image forming unit to form an image from the page in which the image abnormality was detected, and a step of not executing the recovery process, if a type abnormality is detected in the type inspection step before executing the recovery process. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a front view showing an example of an image forming apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram schematically illustrating an example of the internal structure of a paper feed unit. [Figure 3] FIG. 2 is a diagram illustrating an example of an internal configuration of a type inspection unit. [Figure 4] FIG. 2 is a diagram illustrating an example of an internal configuration of an image forming unit. [Figure 5] FIG. 2 is a diagram illustrating an example of an internal configuration of an intermediate paper ejection unit. [Figure 6] FIG. 2 is a diagram schematically illustrating an example of the internal configuration of an image inspection unit. [Figure 7] FIG. 2 is a diagram schematically illustrating an example of the internal configuration of a post-processing unit. [Figure 8] FIG. 2 is a block diagram showing an example of a hardware configuration of the image forming apparatus. [Figure 9] 2 is a block diagram showing an example of functions of a CPU included in the image forming apparatus according to the present embodiment. FIG. [Figure 10] 10 is a flowchart illustrating an example of the flow of a recovery print control process. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are designated by the same reference numerals. The names and functions of these components are also the same. Therefore, detailed description thereof will not be repeated.

[0015] FIG. 1 is a front view showing an example of an image forming apparatus according to an embodiment of the present invention. Referring to FIG. 1, image forming apparatus 1 includes a paper feed unit 11, a type inspection unit 12, an image forming unit 13, an intermediate paper discharge unit 14, an image inspection unit 15, and a post-processing unit 16. Paper feed unit 11, type inspection unit 12, image forming unit 13, intermediate paper discharge unit 14, image inspection unit 15, and post-processing unit 16 are arranged in this order along a conveyance path. Recording media housed in paper feed unit 11 are conveyed along the conveyance path to post-processing unit 16. Recording media are media on which an image can be formed with toner, and include paper sheets such as paper and overhead projector (OHP) sheets. In this embodiment, a case where paper is used as an example of a recording medium will be described.

[0016] FIG. 2 is a diagram schematically illustrating an example of the internal structure of the paper feed unit. Referring to FIG. 2, paper feed unit 11 includes a first paper feed tray 41, a second paper feed tray 42, and a third paper feed tray 43. Each of first paper feed tray 41, second paper feed tray 42, and third paper feed tray 43 can accommodate multiple sheets of paper. The types, sizes, and orientations of the sheets accommodated in each of first paper feed tray 41, second paper feed tray 42, and third paper feed tray 43 may be the same or different. Paper feed unit 11 removes one sheet at a time from either first paper feed tray 41, second paper feed tray 42, or third paper feed tray 43 and supplies the sheet to type inspection unit 12. Each of first paper feed tray 41, second paper feed tray 42, and third paper feed tray 43 is equipped with a pickup roller and a separation roller, which removes one sheet at a time from the topmost sheet of a stack of multiple sheets. The paper sheets picked up by the pickup roller and the separation roller are transported by the supply rollers 44. The supply rollers 44 transport the paper sheets along a transport path P1. The transport path P1 is a path leading to the type inspection unit 12. The paper sheets transported by the supply rollers 44 proceed along the transport path P1 and are supplied to the type inspection unit 12.

[0017] 3 is a diagram schematically illustrating an example of the internal configuration of the type inspection unit. Referring to FIG. 3, the type inspection unit 12 includes a type sensor 45, a first conveyance roller 46, and a first discharge roller 47. The first conveyance roller 46 receives the paper supplied from the paper supply unit 11 and conveys the paper along a conveyance path P1. The first discharge roller 47 receives the paper conveyed by the first conveyance roller 46 and conveys the paper. The paper conveyed by the first discharge roller 47 is conveyed along the conveyance path P1 and supplied to the image forming unit 13.

[0018] The type sensor 45 is disposed between the first conveying roller 46 and the first discharging roller 47. The type sensor 45 is an optical sensor having a detection area within the conveying path P1.

[0019] The type sensor 45 is a transmissive sensor. A transmissive optical sensor includes a light-emitting element and a light-receiving element, which are arranged to face each other across the transport path P1. The type sensor 45 detects paper in the area within the transport path P1 between the light-emitting element and the light-receiving element. The type sensor 45 outputs a value indicating light transmittance. The transmittance indicates the ratio of the amount of light received by the light-receiving element to the amount of light output by the light-emitting element. The light transmittance varies depending on the basis weight of the paper, and there is a predetermined relationship between the light transmittance and the basis weight of the paper. The greater the basis weight of the paper, the smaller the light transmittance. Therefore, by determining the relationship between the basis weight of the paper and the light transmittance through experiments, etc., the basis weight of the paper can be determined from the light transmittance.

[0020] The type sensor 45 may also be a reflective optical sensor. A reflective optical sensor includes a light-emitting element and a light-receiving element, which are arranged on one side of the transport path P1. The reflective optical sensor outputs a value indicating the reflectance of light. The reflectance indicates the ratio of the amount of light received by the light-receiving element to the amount of light output by the light-emitting element. The reflectance of light varies depending on the condition of the paper surface, and there is a predetermined relationship between the reflectance of light and the color of the paper surface. The whiter the paper surface, the greater the reflectance of light. Therefore, by determining the relationship between the whiteness of the paper and the reflectance of light through experiments, etc., the whiteness of the paper can be determined from the reflectance of light.

[0021] The type sensor 45 may also include an ultrasonic sensor. The ultrasonic sensor includes an ultrasonic transmitter and an ultrasonic receiver and is a transmission type. The ultrasonic sensor is arranged so that the ultrasonic transmitter and ultrasonic receiver face each other across the conveying path P1. The ultrasonic transmitter includes a piezoelectric element and a drive circuit for the piezoelectric element, and emits ultrasonic waves. The ultrasonic receiver includes a piezoelectric element and a detection circuit for detecting electromotive force generated in the piezoelectric element, and detects the electromotive force generated in the piezoelectric element by the ultrasonic waves transmitted from the ultrasonic transmitter. The area within the conveying path P1 between the ultrasonic transmitter and the ultrasonic receiver is the detection area.

[0022] The ultrasonic sensor outputs a value indicating the attenuation of ultrasonic waves. Here, the value indicating the attenuation of ultrasonic waves is referred to as the attenuation rate. The attenuation rate of ultrasonic waves differs significantly between stacked sheets of paper, which are made up of multiple sheets of paper, and a single sheet of paper. This is because stacked sheets consist of two sheets of paper overlapping each other. When two sheets of paper overlap, a gap exists between the two sheets, so the attenuation rate of ultrasonic waves due to the stacked sheets is significantly smaller than the attenuation rate of ultrasonic waves due to a single sheet of paper. Therefore, the presence or absence of overlapping two sheets of paper can be detected from the ultrasonic attenuation rate. The attenuation rate also indicates the ratio of the volume of ultrasonic waves transmitted through the object being conveyed to the volume of ultrasonic waves emitted. The attenuation rate of ultrasonic waves varies depending on the basis weight of the paper, and there is a predetermined relationship between the attenuation rate of ultrasonic waves and the basis weight of the paper. The greater the basis weight of the paper, the smaller the attenuation rate of ultrasonic waves. Therefore, the basis weight of the paper may be determined from the ultrasonic attenuation rate by experimentally determining the relationship between the basis weight of the paper and the attenuation rate of ultrasonic waves.

[0023] FIG. 4 is a schematic diagram illustrating an example of the internal configuration of the image forming unit. Referring to FIG. 4, the image forming unit 13 includes image forming units 20Y, 20M, 20C, and 20K, which correspond to yellow, magenta, cyan, and black, respectively. Here, "Y," "M," "C," and "K" represent yellow, magenta, cyan, and black, respectively. Printing data for yellow, magenta, cyan, and black is input to the image forming units 20Y, 20M, 20C, and 20K, respectively. Since the image forming units 20Y, 20M, 20C, and 20K differ only in the color of the toner they use, we will explain the image forming unit 20Y for forming a yellow image. Hereinafter, for the sake of explanation, the horizontal direction perpendicular to the paper transport direction is referred to as the front-to-rear direction. The direction from the back to the front is referred to as the front, and the direction from the front to the back is referred to as the rear.

[0024] The image forming unit 20Y includes a developing device 21Y, a photosensitive drum 22Y which is an image carrier, a charging roller 23Y, an exposure device 24Y, a primary transfer roller 26Y, a toner bottle 27Y, and a toner hopper 28Y.

[0025] Toner bottle 27Y, toner hopper 28Y, and developing unit 21Y are arranged in this order on a path along which toner is transported. Toner hopper 28Y is arranged immediately before developing unit 21Y. Toner is supplied from toner hopper 28Y to developing unit 21Y via the toner transport path.

[0026] The developing unit 21Y includes a developing roller 25Y, which has a built-in magnet roller and holds the charged toner stored in the developing unit 21Y by magnetic force. The photosensitive drum 22Y has a cylindrical shape, and around the photosensitive drum 22Y, a charging roller 23Y, an exposure device 24Y, a developing roller 25Y, and a primary transfer roller 26Y are arranged in this order along the rotation direction of the photosensitive drum 22Y.

[0027] After the surface of the photosensitive drum 22Y is charged by the charging roller 23Y, it is irradiated with laser light emitted by the exposure device 24Y. The exposure device 24Y exposes an image-corresponding portion of the surface of the photosensitive drum 22Y to light, forming an electrostatic latent image. This forms an electrostatic latent image on the photosensitive drum 22Y. Next, the developing device 21Y develops the electrostatic latent image formed on the photosensitive drum 22Y with toner. Specifically, toner held by the developing roller 25Y is placed on the electrostatic latent image formed on the photosensitive drum 22Y by the action of electric field force, thereby forming a toner image on the photosensitive drum 22Y. The toner image formed on the photosensitive drum 22Y is transferred onto the intermediate transfer belt 29, which is an image carrier, by the action of electric field force using the primary transfer roller 26Y.

[0028] The intermediate transfer belt 29 is suspended by a drive roller R1 and a driven roller R2 so as not to slacken. When the drive roller R1 rotates clockwise in FIG. 1, the intermediate transfer belt 29 rotates clockwise in the drawing at a predetermined speed. As the intermediate transfer belt 29 rotates, the driven roller R2 also rotates clockwise.

[0029] As a result, the image forming units 20Y, 20M, 20C, and 20K transfer toner images onto the intermediate transfer belt 29 in this order. The timing at which each of the image forming units 20Y, 20M, 20C, and 20K transfers a toner image onto the intermediate transfer belt 29 is adjusted by detecting a reference mark on the intermediate transfer belt 29. As a result, yellow, magenta, cyan, black, and white toner images are superimposed on the intermediate transfer belt 29.

[0030] A receiving roller R5, a secondary transfer roller R3, a pair of fixing rollers R4, and a discharge roller R6 are arranged in this order in the conveying direction along the conveying path P1. The receiving roller R5 receives the paper conveyed from the type inspection unit 12 and conveys the paper toward the secondary transfer roller R3.

[0031] The secondary transfer roller R3 is disposed opposite the driven roller R2. An electric field force is generated between the secondary transfer roller R3 and the driven roller R2 by the secondary transfer roller R3. As a result, when a sheet of paper transported along the transport path P1 passes between the secondary transfer roller R3 and the driven roller R2, the toner image formed on the intermediate transfer belt 29 is transferred to the first side of the sheet of paper by the action of the electric field force. The sheet of paper onto which the toner image has been transferred is transported to the pair of fixing rollers R4. The pair of fixing rollers R4 heats and pressurizes the sheet of paper passing between them. This melts the toner and fixes it to the first side of the sheet of paper.

[0032] A first switching claw 33 is disposed on the transport path P1 between the pair of fixing rollers R4 and the discharge rollers R6. The image forming unit 13 includes a reversing device 30 below the transport path P1. The reversing device 30 includes a reversing path P2, a reversing roller R7 disposed on the reversing path P2, and an evacuation tray 34. The first switching claw 33 switches the paper's traveling direction to either the transport path P1 or the reversing path P2. When the first switching claw 33 switches the paper's traveling direction to the transport path P1, the paper transported by the pair of fixing rollers R4 travels along the transport path P1 and is received by the discharge rollers R6. The discharge rollers R6 receive the paper transported by the pair of fixing rollers R4 and transport the paper. The paper transported by the discharge rollers R6 travels along the transport path P1 and is supplied to the intermediate paper discharge unit 14.

[0033] When the first switching claw 33 switches the paper travel direction to the reverse path P2, the paper transported by the fixing roller pair R4 travels along the reverse path P2. The reverse path P2 includes an evacuation path 31 and a resupply path 32. The evacuation path 31 is a path that leads from a position upstream of the first switching claw 33 on the transport path P1 to the evacuation tray 34. The resupply path 32 is a path that leads from the evacuation tray 34 to a position upstream of the receiving roller R5 on the transport path P1.

[0034] When first switching claw 33 switches the paper travel direction to reverse path P2, the paper transported by fixing roller pair R4 enters retreat path 31. A plurality of rollers are arranged on retreat path 31, and the plurality of rollers transport the paper. The paper transported by the plurality of rollers on retreat path 31 proceeds along retreat path 31 and is received by reverse roller R7.

[0035] The reversing roller R7 rotates in a forward direction to transport the paper toward the evacuation tray 34. After transporting a predetermined amount of paper to the evacuation tray 34, the reversing roller R7 reverses its rotation direction and rotates in the opposite direction. When the reversing roller R7 rotates in the opposite direction, the paper, part of which is stored in the evacuation tray 34, is transported in the opposite direction to the direction in which it was transported up to that point, and enters the resupply path 32. The resupply path 32 is provided with multiple rollers that transport the paper. The paper transported by the multiple rollers is transported along the resupply path 32 and enters the transport path P1.

[0036] Receiving roller R5 receives the paper sheet transported along resupply path 32 by the multiple rollers of resupply path 32, and transports the paper sheet toward secondary transfer roller R3. The upward-facing side of the paper sheet received by receiving roller R5 through resupply path 32 is the second side opposite to the first side that faces upward while the paper sheet is supplied from type inspection unit 12 and transported along transport path P1. Therefore, an image is formed on the second side of the paper sheet transported along resupply path 32 while it is transported along transport path P1 by receiving roller R5.

[0037] When forming a full-color image, the image forming section 13 drives all of the image forming units 20Y, 20M, 20C, and 20K, but when forming a monochrome image, it drives any one of the image forming units 20Y, 20M, 20C, and 20K. An image can also be formed by combining two or more of the image forming units 20Y, 20M, 20C, and 20K.

[0038] 5 is a diagram showing an example of the internal configuration of the intermediate paper discharge unit. Referring to FIG. 5, the intermediate paper discharge unit 14 includes an intermediate purge tray 61, a second switching claw 63, a first receiving roller 64, a first paper discharge roller 65, and a first purge roller 67. The first receiving roller 64 and the first paper discharge roller 65 are arranged in this order on the conveyance path P1 in the paper conveyance direction. The first receiving roller 64 receives the paper conveyed from the image forming unit 13 and conveys the paper toward the first paper discharge roller 65.

[0039] A second switching claw 63 is disposed on the conveying path P1 between the first receiving roller 64 and the first paper discharge roller 65. In the intermediate paper discharge unit 14, an intermediate purge path P3 that branches off from the conveying path P1 is formed above the conveying path P1. The second switching claw 63 switches the traveling direction of the paper to either the conveying path P1 or the intermediate purge path P3.

[0040] When the second switching claw 63 switches the paper travel direction to the transport path P1, the paper transported by the first receiving rollers 64 travels along the transport path P1. The first paper ejection rollers 65 accept the paper transported by the first receiving rollers 64 and transport the paper. The paper transported by the first paper ejection rollers 65 travels along the transport path P1 and is supplied to the image inspection unit 15.

[0041] When the second switching claw 63 switches the paper travel direction to the intermediate purge path P3, the paper transported by the first receiving roller 64 travels along the intermediate purge path P3. The intermediate purge path P3 is a path that extends from the branch point upstream of the second switching claw 63 on the transport path P1 to the intermediate purge tray 61.

[0042] When the second switching claw 63 switches the paper travel direction to the intermediate purge path P3, the paper transported by the first receiving roller 64 enters the intermediate purge path P3 and is received by the first purge roller 67. The paper transported by the first purge roller 67 proceeds along the intermediate purge path P3 and is discharged to the intermediate purge tray 61.

[0043] 6 is a diagram schematically illustrating an example of the internal configuration of the image inspection unit. Referring to FIG. 6, the image inspection unit 15 includes a reading unit 51, a first conveyance roller 52, and a second conveyance roller 53. The first conveyance roller 52 receives the paper sheet discharged from the intermediate paper discharge unit 14 and conveys the paper sheet along a conveyance path P1. The second conveyance roller 53 receives the paper sheet conveyed by the first conveyance roller 52 and conveys the paper sheet. The paper sheet conveyed by the second conveyance roller 53 is conveyed along the conveyance path P1 and supplied to the post-processing unit 16.

[0044] The reading unit 51 is disposed between the first conveyor roller 52 and the second conveyor roller 53. The reading unit 51 includes a first CIS 51a and a second CIS 51b disposed on either side of the conveyance path P1. The first CIS 51a and the second CIS 51b are contact image sensors, each including a plurality of photoelectric conversion elements arranged on a reading surface aligned in a main scanning direction that intersects with the conveyance direction of the paper. The first CIS 51a and the second CIS 51b are disposed with their respective reading surfaces facing the conveyance path P1. Therefore, while the paper passes between the first CIS 51a and the second CIS 51b, the top and bottom surfaces of the paper are read by the first CIS 51a and the second CIS 51b, respectively.

[0045] 7 is a diagram schematically illustrating an example of the internal configuration of the post-processing unit. Referring to FIG. 7, the post-processing unit 16 includes a paper discharge tray 71, a purge tray 72, a third switching claw 73, a second receiving roller 74, a second purge roller 75, and a second paper discharge roller 76. The second receiving roller 74 and the second paper discharge roller 76 are arranged in this order on the conveyance path P1 in the paper conveyance direction. The second receiving roller 74 receives the paper conveyed from the image inspection unit 15 and conveys it toward the second paper discharge roller 76.

[0046] A third switching claw 73 is disposed on the conveying path P1 between the second receiving roller 74 and the second paper discharge roller 76. In the post-processing section 16, a purge path P4 is formed above the conveying path P1, branching off from the conveying path P1. The third switching claw 73 switches the traveling direction of the paper to either the conveying path P1 or the purge path P4.

[0047] When the third switching claw 73 switches the paper travel direction to the transport path P1, the paper transported by the second receiving rollers 74 travels along the transport path P1. The second paper discharge rollers 76 receive the paper transported by the second receiving rollers 74 and transport the paper. The paper transported by the second paper discharge rollers 76 travels along the transport path P1 and is discharged onto the paper discharge tray 71.

[0048] When the third switching claw 73 switches the paper travel direction to the purge path P4, the paper transported by the second receiving roller 74 travels along the purge path P4. The purge path P4 is a path that extends from the branch point upstream of the third switching claw 73 on the transport path P1 to the purge tray 72.

[0049] When the third switching claw 73 switches the paper travel direction to purge path P4, the paper transported by the second receiving roller 74 enters purge path P4 and is received by the second purge roller 75. The paper transported by the second purge roller 75 proceeds along purge path P4 and is discharged to the purge tray 72.

[0050] Although not shown in the figure, post-processing unit 16 includes a mechanism for performing post-processing on sheets. The mechanism for performing post-processing includes processes for processing sheets. The processes for processing sheets include a punching process for forming punch holes, a stapling process for driving staples into a stack of multiple sheets, and a bending process for folding sheets.

[0051] Fig. 8 is a block diagram showing an example of the hardware configuration of an image forming apparatus. Referring to Fig. 8, image forming apparatus 1 includes a main circuit 110. Main circuit 110 is provided in any of paper feed unit 11, type inspection unit 12, image forming unit 13, intermediate paper discharge unit 14, image inspection unit 15, and post-processing unit 16. Here, an example will be described in which main circuit 110 is provided in image forming unit 13. Note that main circuit 110 may be provided in a housing separate from paper feed unit 11, type inspection unit 12, image forming unit 13, intermediate paper discharge unit 14, image inspection unit 15, and post-processing unit 16.

[0052] The main circuit 110 includes a CPU (Central Processing Unit) 111 that controls the entire image forming apparatus 1, a communication interface (I / F) unit 112, a ROM (Read Only Memory) 113, a RAM (Random Access Memory) 114, a hard disk drive (HDD) 115 as a large-capacity storage device, and an external storage device 118. The CPU 111 is connected to the paper feed unit 11, the type inspection unit 12, the image forming unit 13, the intermediate paper discharge unit 14, the image inspection unit 15, the post-processing unit 16, and the operation panel 18, and controls the entire image forming apparatus 1.

[0053] ROM 113 stores programs executed by CPU 111 or data required to execute the programs. RAM 114 is used as a work area when CPU 111 executes the programs. RAM 114 also temporarily stores image data continuously sent from document reading unit 130.

[0054] The communication I / F unit 112 is an interface for connecting the image forming apparatus 1 to a network. The communication I / F unit 112 communicates with other computers or data processing devices connected to the network using a communication protocol such as TCP (Transmission Control Protocol) or FTP (File Transfer Protocol). The network to which the communication I / F unit 112 is connected is a local area network (LAN), and the connection type may be either wired or wireless. Furthermore, the network is not limited to a LAN, and may be a wide area network (WAN), a public switched telephone network (PSTN), the Internet, or the like.

[0055] External storage device 118 is controlled by CPU 111, and is equipped with a CD-ROM (Compact Disk Read Only Memory) 119 or a semiconductor memory. In this embodiment, an example will be described in which CPU 111 executes a program stored in ROM 113. CPU 111 may control external storage device 118 to read a program to be executed by CPU 111 from CD-ROM 119, store the read program in RAM 114, and execute it.

[0056] The recording medium for storing the programs executed by CPU 111 is not limited to CD-ROM 119, but may be a flexible disk, cassette tape, optical disk, semiconductor memory, or other medium. Optical disks include magnetic optical discs (MOs), mini discs (MDs), and digital versatile discs (DVDs). Semiconductor memories include IC cards, optical cards, mask ROMs, and erasable programmable ROMs (EPROMs). CPU 111 may also load a program stored in HDD 115 into RAM 114 and execute it. Programs stored in HDD 115 include programs downloaded from a computer connected to the network and stored in HDD 115. Programs stored in HDD 115 also include programs written to HDD 115 by a computer connected to the network. The term "program" as used herein refers not only to programs directly executable by CPU 111 but also to source programs, compressed programs, encrypted programs, and the like.

[0057] Operation panel 18 is provided on the top of the housing of image forming unit 13. Operation panel 18 includes display unit 19a and operation unit 19b. Display unit 19a is, for example, a liquid crystal display (LCD) that displays an instruction menu for the user, information about acquired image data, etc. Note that instead of an LCD, any device that displays images, such as an organic EL (electroluminescence) display, can be used.

[0058] The operation unit 19b includes a touch panel or hard keys. The touch panel detects a position on the display surface of the display unit 19a designated by a user. The hard keys are, for example, contact switches.

[0059] Fig. 9 is a block diagram showing an example of functions of a CPU included in the image forming apparatus 1 according to the present embodiment. The functions shown in Fig. 9 are realized by CPU 111 included in image forming apparatus 1 as CPU 111 executes a print job execution program stored in ROM 113, HDD 115, or CD-ROM 119. Referring to Fig. 9, CPU 111 includes a job acquisition unit 121, a job execution unit 123, an image inspection control unit 125, and a type inspection control unit 127.

[0060] Job acquisition unit 121 acquires a print job. In response to receiving a print job, job acquisition unit 121 outputs the print job to job execution unit 123. Job acquisition unit 121 accepts a print job received by communication I / F unit 112. A print job received from an external computer by communication I / F unit 112 is written in, for example, PJL (Printer Job Language) or PCL (Printer Control Language), and includes printing conditions and data to be used for image formation.

[0061] When a user instructs the operation panel 18 to execute a print job, the job acquisition unit 121 accepts the print job based on the operation input on the operation panel 18. The print job accepted from the operation panel 18 includes print conditions and data to be used for image formation. The data to be used for image formation is data specified by the user. The data specified by the user includes data stored in the HDD 115 and data stored in an external computer.

[0062] The job execution unit 123 executes a print job. The job execution unit 123 controls the paper feed unit 11, the type inspection unit 12, the image forming unit 13, the intermediate paper discharge unit 14, the image inspection unit 15, and the post-processing unit 16 to form an image on paper and post-process the paper on which the image has been formed.

[0063] The job execution unit 123 controls the paper feed unit 11, selects one of the first paper feed tray 41, the second paper feed tray 42, and the third paper feed tray 43 according to the printing conditions, and transports the paper stored in the selected one as the object to be transported.

[0064] Job execution unit 123 generates print data based on the data to be used for image formation in accordance with the print conditions included in the print job. The print data includes four pieces of data corresponding to yellow, magenta, cyan, and black. Therefore, if the print data consists of multiple pages, each of the multiple pages includes four pieces of data corresponding to yellow, magenta, cyan, and black.

[0065] The type inspection control unit 127 controls the type sensor 45 to acquire information about the physical properties of the paper. The type inspection control unit 127 determines the type of paper based on the information about the physical properties of the paper. The information about the physical properties includes information indicating basis weight. The relationship between light transmittance and basis weight is determined in advance through experiments or simulations, and the determined relationship is maintained. The type inspection control unit 127 determines the basis weight from the light transmittance based on this relationship. Furthermore, the type inspection control unit 127 determines the type of paper from the determined basis weight by referencing a table that defines the relationship between paper type and basis weight. The basis weight may be determined from the ultrasonic attenuation rate or the optical transmittance. For example, the relationship between the ultrasonic attenuation rate and basis weight is determined in advance through experiments or simulations, and the determined relationship is maintained. In this case, the type inspection control unit 127 determines the basis weight from the ultrasonic attenuation rate based on this relationship.

[0066] The paper type includes plain paper, high-quality paper, recycled paper, and photo paper. The type inspection control unit 127 determines whether the paper type is normal or not by detecting the paper type. The type inspection control unit 127 determines whether the paper type matches the type specified in the print job. If the paper type does not match the type specified in the print job, the type inspection control unit 127 outputs a type abnormality signal to the job execution unit 123, indicating that the type is abnormal.

[0067] The information on physical properties may also include information indicating the thickness of the paper. The relationship between light transmittance and thickness is determined in advance by experiment or simulation, and the determined relationship is maintained. The type inspection control unit 127 determines the thickness from the light transmittance based on this relationship. Furthermore, the type inspection control unit 127 determines the type of paper from the determined thickness by referring to a table that defines the relationship between paper type and thickness. The thickness of the paper may also be determined from the ultrasonic attenuation rate or light transmittance.

[0068] The information about physical properties may also include information indicating whiteness, whether or not the surface is coated, hardness, and whether or not it is an envelope. Whiteness and whether or not the surface is coated are determined based on light reflectance. Whether or not it is an envelope is determined based on the attenuation rate of ultrasonic waves. The type inspection control unit 127 determines that an item is an envelope if the attenuation rate of ultrasonic waves is equal to or less than a threshold, and determines that it is paper if it is greater than the threshold.

[0069] The job execution unit 123 includes a recovery control unit 131, a recovery prohibition unit 133, and a job cancellation unit 135. The job cancellation unit 135 cancels the execution of a print job in response to a type abnormality signal being input from the type inspection control unit 127. Specifically, the job cancellation unit 135 controls the paper feed unit 11 to stop paper feeding, and controls the intermediate paper ejection unit 14 to purge the paper before image formation. The paper to be purged is paper that has already been supplied from the paper feed unit 11 and has not yet had an image formed on it by the image forming unit 13 at the stage when the type abnormality signal is input from the type inspection control unit 127. The job cancellation unit 135 controls the image forming unit 13 to transport the paper to the intermediate paper ejection unit 14 without forming an image on the paper to be purged. Furthermore, the job canceling unit 135 controls the intermediate paper ejection unit 14 to switch the second switching claw 63 to the intermediate purge path P3, and ejects the paper to be purged onto the intermediate purge tray 61.

[0070] At the stage when the job cancellation unit 135 cancels the execution of the print job, the image forming unit 13 may be forming an image on the paper. The job cancellation unit 135 causes the image forming unit 13 to continue forming the image on the paper. The job cancellation unit 135 causes the paper on which the image has been formed by the image forming unit 13 to be transported to the intermediate paper discharge unit 14. The paper transported to the intermediate paper discharge unit 14 is inspected for the image in the image inspection unit 15 and then discharged from the post-processing unit 16.

[0071] The image inspection control unit 125 controls the image inspection unit 15 to inspect the image formed on the paper. The image inspection control unit 125 acquires first inspection data output by the first CIS 51a of the image inspection unit 15 after reading the paper, and second inspection data output by the second CIS 51b after reading the paper. The image inspection control unit 125 determines whether the image is normal based on the first inspection data and the second inspection data. For example, the image inspection control unit 125 compares the first inspection data and the second inspection data with the data included in the print job. If either the first inspection data or the second inspection data differs from the data included in the print job, the image inspection control unit 125 outputs an image abnormality signal indicating an image abnormality to the job execution unit 123.

[0072] The recovery control unit 131 provided in the job execution unit 123 executes purge processing and recovery processing in response to an image abnormality signal being input from the image inspection control unit 125. While a print job is being executed, multiple sheets of paper are being transported between the image inspection unit 15 and the paper feed unit 11. The purge processing is processing in which multiple sheets of paper, including sheets on which an image of a page determined to have an image abnormality is formed, are discharged to the purge tray 72. The recovery processing is processing in which image formation is resumed from the page determined to have an image abnormality.

[0073] Specifically, the recovery control unit 131 identifies a page corresponding to an image formed on a sheet determined to have an image abnormality by the image inspection control unit 125. The multiple sheets to be purged include the sheet on which the image of the page determined to have an image abnormality is formed and one or more subsequent sheets transported after that sheet. The multiple sheets to be purged include sheets whose type has not been detected by the type inspection unit 12. The recovery control unit 131 controls the post-processing unit 16 to switch the third switching claw 73 to purge path P4 and discharge the multiple sheets to be purged to the purge tray 72.

[0074] The multiple sheets of paper to be purged include sheets of paper whose types have not been detected by the type inspection unit 12. However, because the multiple sheets of paper to be purged are discharged to the purge tray 72, there is no need for the type inspection unit 12 to detect the type. However, in this embodiment, the recovery prohibition unit 133 outputs a detection instruction to the type inspection control unit 127 when the recovery control unit 131 decides to execute recovery processing. If the type inspection control unit 127 receives a detection instruction from the recovery prohibition unit 133 when it has been decided to execute recovery processing, the type inspection control unit 127 controls the type inspection unit 12 to inspect the type of the sheets of paper to be purged. If the type inspection control unit 127 detects a type abnormality in any of the sheets of paper to be purged, it outputs a type abnormality signal to the recovery prohibition unit 133 and the job cancellation unit 135.

[0075] The recovery prohibition unit 133 outputs a prohibition command indicating that the execution of the recovery process is to be prohibited to the recovery control unit 131 in response to input of the type abnormality signal from the type inspection control unit 127. When the prohibition command is input from the recovery prohibition unit 133 after the recovery control unit 131 has decided to execute the recovery process, the recovery control unit 131 executes the purge process but does not execute the recovery process.

[0076] The job canceling unit 135 cancels the print job in response to a type abnormality signal being input from the type inspection control unit 127 after the recovery control unit 131 has decided to execute the recovery process. Therefore, paper that is likely to be determined to be type abnormal is not conveyed from the paper feed unit 11.

[0077] In this way, at the stage when the recovery control unit 131 decides to execute the recovery process, the type of the paper that is the target of the purging process but whose type has not been inspected by the type inspection control unit 127 is inspected. Then, if the type inspection control unit 127 detects an abnormal type among the paper that is the target of the purging process, the recovery control unit 131 is prohibited from executing the recovery process, and the job cancellation unit 135 cancels the print job. This prevents new paper from being supplied from the paper feed unit 11, thereby reducing unnecessary paper consumption.

[0078] 10 is a flowchart showing an example of the flow of recovery printing control processing. The recovery printing control processing is processing that is executed by CPU 111 provided in image forming apparatus 1 as CPU 111 executes a print job execution program stored in ROM 113, HDD 115, or CD-ROM 119. Referring to FIG. 10, CPU 111 acquires a print job (step S01), and proceeds to step S02.

[0079] In step S02, CPU 111 executes the print job and proceeds to step S03. In step S03, CPU 111 determines whether a type abnormality has been detected. If a type abnormality has been detected, the process proceeds to step S06; if not, the process proceeds to step S04. In step S06, CPU 111 cancels execution of the print job and proceeds to step S07. In step S07, CPU 111 performs intermediate purge processing and ends the process. The intermediate purge processing is processing in which sheets in the process of being transported after the sheet for which the type abnormality has been detected are discharged to intermediate purge tray 61. Since the type abnormality is detected by type inspection unit 12, all sheets after the sheet for which the type abnormality has been detected by type inspection unit 12 out of the multiple sheets of paper supplied from paper feed unit 11 are discharged to intermediate purge tray 61.

[0080] In step S04, it is determined whether an image quality abnormality has been detected. If an image abnormality has been detected, the process proceeds to step S08; if not, the process proceeds to step S05. In step S08, it is determined that recovery processing is to be performed, and the process proceeds to step S09. In step S09, the page on which the image abnormality has been detected is identified, and the process proceeds to step S10. In step S10, the sheets on which the image of the page on which the image abnormality has been detected has been formed and which are in the process of being conveyed after that sheet are purged, and the process proceeds to step S11. The sheet on which the image of the page on which the image abnormality has been detected has been formed and the sheets on which the sheet on which the image abnormality has been detected has been conveyed are discharged to purge tray 72.

[0081] In step S11, CPU 111 determines whether a type abnormality has been detected among the sheets to be purged. If a type abnormality has been detected, the process proceeds to step S13; otherwise, the process proceeds to step S12. In step S12, CPU 111 executes recovery processing and proceeds to step S05. Image formation is resumed from the page identified in step S09. In step S05, it is determined whether the print job has ended. If the print job has not ended, the process returns to step S03; if the print job has ended, the process ends.

[0082] In step S13, execution of the recovery process is prohibited, and the process proceeds to step S 14. In step S14, CPU 111 stops execution of the print job and ends the process.

[0083] <Summary of implementation form> (Item 1) A type inspection unit that inspects the type of the recording medium; an image inspection unit that inspects an image formed on a recording medium; a job acquisition unit that acquires a print job including image data consisting of multiple pages; an image forming unit that forms an image on a recording medium; a job execution unit that causes the image forming unit to form an image in accordance with the print job, when an image abnormality is detected by the image inspection unit, the job execution unit executes a recovery process to cause the image forming unit to form an image from the page where the image abnormality is detected; If the type abnormality is detected by the type inspection unit before the recovery process is executed, the image forming apparatus does not execute the recovery process.

[0084] According to this aspect, even if it is determined that recovery processing should be performed, if a type abnormality is detected before the recovery processing is performed, the recovery processing is not performed. If a type abnormality is detected, there is a high probability that the type of the recording medium following the recording medium with the type abnormality is abnormal. Therefore, since the recording medium scheduled to be transported to perform the recovery processing is not transported, a recording medium that is likely to be a type different from the predetermined type is not transported. As a result, an image forming apparatus can be provided that can reduce wasteful consumption of recording media.

[0085] (Item 2) The image forming apparatus according to Item 1, wherein the job execution unit halts execution of the print job when a type abnormality is detected by the type inspection unit.

[0086] According to this aspect, when a type abnormality is detected, the execution of the print job is stopped, so that it is possible to prevent an image from being formed on a recording medium of a type different from the predetermined type.

[0087] (Item 3) In the image forming apparatus according to item 1, the type detection unit detects the type of the recording medium before the image is formed by the image forming unit.

[0088] According to this aspect, the type of recording medium is detected before an image is formed, so that it is possible to prevent an image from being formed on a recording medium of a type different from a predetermined type.

[0089] (Item 4) The image forming apparatus further includes a paper feed unit that supplies a recording medium to the image forming unit, Item 2. The image forming apparatus according to item 1, wherein the job execution unit does not execute the recovery process if the type inspection unit detects a type abnormality in any of one or more recording media supplied from the paper feed unit to the image forming unit at the time the image inspection unit detects an image quality abnormality.

[0090] According to this aspect, if a type abnormality is detected in one or more recording media supplied from the paper feed unit to the image forming unit at the time an image quality abnormality is detected, the recovery process is not executed. Therefore, the recording media that are scheduled to be conveyed to the image forming unit for the recovery process are not conveyed, so it is possible to prevent an image from being formed on a recording medium that is likely to be of a type different from the predetermined type.

[0091] (Item 5) A print job execution method executed in an image forming apparatus having an image forming unit that forms an image on a recording medium, a type checking step of checking the type of the recording medium; an image inspection step of inspecting an image formed on a recording medium; a job acquisition step of acquiring a print job including image data consisting of multiple pages; a job execution step of causing the image forming unit to form an image in accordance with the print job, The job execution step includes a step of executing a recovery process in which, when an image abnormality is detected in the image inspection step, the image formation unit forms an image from the page in which the image abnormality is detected; and if a type abnormality is detected in the type checking step before the recovery process is executed, not executing the recovery process.

[0092] According to this aspect, it is possible to provide a print job execution method that can suppress unnecessary consumption of recording media.

[0093] (Item 6) A print job execution program executed by a computer that controls an image forming apparatus having an image forming unit that forms an image on a recording medium, a type checking step of checking the type of the recording medium; an image inspection step of inspecting an image formed on a recording medium; a job acquisition step of acquiring a print job including image data consisting of multiple pages; a job execution step of causing the image forming unit to form an image in accordance with the print job; The job execution step includes a step of executing a recovery process in which, when an image abnormality is detected in the image inspection step, the image formation unit forms an image from the page in which the image abnormality is detected; and if a type abnormality is detected in the type checking step before the recovery process is executed, not executing the recovery process.

[0094] According to this aspect, it is possible to provide a print job execution program that can reduce wasteful consumption of recording media.

[0095] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0096] 1 image forming device, 11 paper feed unit, 12 type inspection unit, 13 image forming unit, 14 intermediate paper output unit, 15 image inspection unit, 16 post-processing unit, 18 operation panel, 19a display unit, 19b operation unit, 111 CPU, 112 communication I / F unit, 113 ROM, 114 RAM, 115 HDD, 118 external storage device, 119 CD-ROM, 121 job acquisition unit, 123 job execution unit, 125 image inspection control unit, 127 type inspection control unit, 130 document reading unit, 131 recovery control unit, 133 recovery prohibition unit, 135 job cancellation unit.

Claims

1. a type inspection unit that inspects the type of the recording medium; an image inspection unit that inspects an image formed on a recording medium; a job acquisition unit that acquires a print job including image data consisting of multiple pages; an image forming unit that forms an image on a recording medium; a job execution unit that causes the image forming unit to form an image in accordance with the print job, when an image abnormality is detected by the image inspection unit, the job execution unit executes a recovery process to cause the image forming unit to form an image from the page where the image abnormality is detected; If the type abnormality is detected by the type inspection unit before the recovery process is executed, the image forming apparatus does not execute the recovery process.

2. The image forming apparatus according to claim 1 , wherein the job executing section cancels execution of the print job when the type detecting section detects a type abnormality.

3. The image forming apparatus according to claim 1 , wherein the type detection unit detects the type of the recording medium before the image is formed by the image forming unit.

4. a paper feed unit that supplies a recording medium to the image forming unit, 2. The image forming apparatus according to claim 1, wherein the job execution unit does not execute the recovery process if the type inspection unit detects a type abnormality in any of the one or more recording media supplied from the paper feed unit at the time the image inspection unit detects an image quality abnormality.

5. A print job execution method executed in an image forming apparatus having an image forming unit that forms an image on a recording medium, a type checking step of checking the type of the recording medium; an image inspection step of inspecting an image formed on a recording medium; a job acquisition step of acquiring a print job including image data consisting of multiple pages; a job execution step of causing the image forming unit to form an image in accordance with the print job, The job execution step includes a step of executing a recovery process in which, when an image abnormality is detected in the image inspection step, the image formation unit forms an image from the page in which the image abnormality is detected; and if a type abnormality is detected in the type checking step before the recovery process is executed, not executing the recovery process.

6. A print job execution program executed by a computer that controls an image forming apparatus having an image forming unit that forms an image on a recording medium, a type checking step of checking the type of the recording medium; an image inspection step of inspecting an image formed on a recording medium; a job acquisition step of acquiring a print job including image data consisting of multiple pages; a job execution step of causing the image forming unit to form an image in accordance with the print job; The job execution step includes a step of executing a recovery process in which, when an image abnormality is detected in the image inspection step, the image formation unit forms an image from the page in which the image abnormality is detected; and a step of not executing the recovery process if a type abnormality is detected in the type checking step before the recovery process is executed.

Images