JP2020088534A - Image inspection device and image formation system - Google Patents

Abstract

To provide an image inspection device capable of detecting, at a real time, a foreign matter existing on an image reading surface of a reading part that reads an image, and capable of continuing an image inspection while the foreign matter exists.SOLUTION: An image inspection device 500 is provided that includes: a transportation part 310 transporting a paper sheet; a first reading part 511 which is arranged in the transportation part 310 and reads an image of the paper sheet to be transported; a second reading part 512 which is arranged in the transportation part 310, and reads the image of the paper sheet; and a control part 360 which detects a foreign matter adhered to any one of or both of the first reading part 511 and the second reading part 512 from a difference between a first image obtained by the first reading part 511 and a second image obtained by a second reading part 512.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image inspection device and an image forming system.

The image inspection apparatus inspects the image printed on the sheet by reading the image printed on the sheet by the image forming system with the reading unit.

In such an image inspection apparatus, in order to protect the inside of the reading unit, there is glass (called platen glass or the like) on the side of the reading unit on which the paper is conveyed. Therefore, if a foreign substance is present on the surface of the glass (the surface on the side where the paper is conveyed), a reading error will occur.

As a technique for solving such a problem of foreign matter in the reading unit, for example, in the image reading apparatus of Patent Document 1, a plurality of light receiving sensors are provided for one sheet of glass on which the sheet is conveyed. And a matching degree calculating means for calculating the matching degree of the overlapping portion of the first image and the second image obtained by reading the paper by the light receiving sensors adjacent to each other, and the focus based on the result by the matching degree calculating means. Determining means for determining whether images with different depths exist, and if the determining means determines that images with different depths of focus exist, detecting consecutive images in the transport direction for each image with different depths of focus. Therefore, a foreign matter detecting unit for detecting a foreign matter on the reading glass surface is provided. According to this technique, whether or not a noise image due to foreign matter such as dust or dust on the reading glass surface is accurately determined from the read image and the presence of foreign matter can be detected with high accuracy.

Further, for example, in the image reading apparatus of Patent Document 2, a first image reading unit that reads an image of a document conveyed at a first document reading position on a document table, and a document conveyance from the first document reading position. Abnormality that detects an abnormal pixel caused by dust moving with the paper between the second image reading unit and the first image reading unit and the second image reading unit that are apart from each other by a predetermined distance in the direction. And a pixel detector. According to this technique, the probability of erroneously detecting vertical line image data existing in a document as dust is also reduced, and it is also suitable for abnormal images caused by relatively long dust such as lint and hair. It is said that it can be detected.

JP, 2005-184033, A JP, 2006-197484, A

However, in Patent Document 1, although a plurality of light receiving sensors are used, a sheet on one glass surface is read by the plurality of light receiving sensors. I will read the foreign matter. Further, when a blank sheet is read, only one peak of the degree of coincidence appears, so that the foreign matter cannot be discriminated. Further, when a foreign substance is detected, the image forming system needs to be stopped and cleaned.

Further, in Patent Document 2, since there are two reading positions on one glass surface, it is not possible to identify a foreign substance that extends over the glass surface. Further, as in Patent Document 1, when a foreign substance is detected, it is necessary to stop and clean the image forming system.

Therefore, an object of the present invention is to detect an alien substance in real time when the alien substance is present on the image reading surface of the reading unit, and to continue the image inspection even when the alien substance is present, and An object is to provide an image forming system.

The above object of the present invention can be achieved by the following means.

(1) In an image inspection device that inspects an image formed on a sheet,
A transport unit for transporting the sheet,
A first reading unit which is arranged at a first reading position on the conveying unit and which reads an image of the conveyed sheet;
A second reading unit which is arranged at a second reading position on the carrying unit, which is separated from the first reading position by a predetermined distance in the carrying direction of the paper, and which reads an image on the paper;
Detecting foreign matter adhering to one or both of the first reading unit and the second reading unit from the difference between the first image obtained by the first reading unit and the second image obtained by the second reading unit Control unit to
An image inspection apparatus having:

(2) The image inspection apparatus according to (1), wherein the first reading unit and the second reading unit each have an independent transparent member on a side where the sheet is conveyed and read an image.

(3) The image inspection apparatus according to (1) or (2), wherein, when the foreign matter is detected, the control unit excludes the region where the foreign matter is detected from the region to be inspected.

(4) The image inspection apparatus according to any one of (1) to (3), in which the control unit does not use a site excluded from the region to be inspected for the inspection of subsequent images.

(5) In the above (1) to (4), the first reading unit and the second reading unit are provided on the downstream side of the image forming apparatus that forms an image on the sheet in the sheet conveying direction. The image inspection apparatus according to any one of claims.

(6) The image inspection apparatus according to (5), wherein the control unit does not stop the operation of the image forming apparatus when the foreign matter is detected.

(7) The control unit causes the image forming apparatus to form an alignment mark on a sheet surface outside the image forming area,
The image inspection apparatus according to (5) or (6) above, which aligns the first image and the second image with the alignment mark as a reference.

(8) The image inspection apparatus according to (7) above, wherein the alignment mark is a line in a conveyance direction of the sheet and a line intersecting the conveyance direction.

(9) The control unit detects a difference between a line width of the alignment mark in the first image and a line width of the alignment mark in the second image. (8) Image inspection device.

(10) The control unit may eliminate the difference between the line width of the alignment mark in the first image and the line width of the alignment mark in the second image so as to eliminate the difference between the first image and the line. The image inspection apparatus according to (9) above, wherein the line widths of the alignment marks in each of the second images are matched.

(11) The image inspection apparatus according to any one of (5) to (10), wherein the first reading unit and the second reading unit read an image formed by the image forming apparatus inline.

(12) The image inspection apparatus according to any one of (5) to (11), wherein the control unit feeds back one or both of the first image and the second image to the image forming apparatus. ..

(13) The image inspection apparatus according to any one of (1) to (12), wherein the paper is continuous paper.

(14) An image forming apparatus that forms an image on a sheet,
An image inspection apparatus according to any one of (1) to (13) above,
Image forming system having a.

According to the present invention, the first reading unit and the second reading unit read the respective images and detect the foreign matter from the difference between the two images. Therefore, when the foreign matter is present on the image reading surface of the reading unit, the foreign matter is detected. Can be detected in real time, and the image inspection can be continued even if a foreign substance is present.

FIG. 1 is a schematic diagram showing an image forming system according to this embodiment. It is a block diagram for explaining a control system. It is a schematic perspective view for explaining a reading unit. It is a schematic sectional drawing which follows the AA line of the reading part shown in FIG. It is explanatory drawing for demonstrating image matching. It is an explanatory view for explaining line width correction processing. It is a flow chart which shows a processing procedure which operates an image inspection device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. Also, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may differ from the actual ratios.

FIG. 1 is a schematic diagram showing an image forming system according to this embodiment.

The image forming system 10 according to the present embodiment forms an image on the paper P that is continuous paper. Here, roll paper is illustrated as the paper P. However, the paper P does not necessarily need to be held in a roll shape, and may be continuous paper that is folded and held. Further, although only one roll paper is shown in FIG. 1, a plurality of roll papers may be held.

The image forming system 10 includes a paper feeding device 100, an image forming device 300, an image inspection device 500, and an image inspection device 500 from the upstream side with the transport direction (arrow F in FIG. 1) of the paper P during image formation (printing) as the forward direction. The paper discharge device 700 is connected. In the following description, the terms “upstream” and “downstream” refer to the upstream and the downstream with respect to the conveyance direction of the paper P during printing.

The paper feeding device 100 is a device that feeds the paper P to the image forming apparatus 300. In the housing of the paper feeding device 100, for example, the paper P is wound around a support shaft and rotatably held. The sheet feeding device 100 conveys the sheet P wound around the support shaft to the outside at a constant speed via a plurality of rollers (for example, a feeding roller and a sheet feeding roller). A paper feed adjusting unit 150 is provided in the paper feed device 100 between the paper feed device 100 and the image forming apparatus 300. The paper feed adjusting unit 150 absorbs the speed difference between the transport speed at which the paper P is fed from the paper feeder 100 and the transport speed of the paper P in the image forming apparatus 300.

The image forming apparatus 300 includes a conveyance unit 310, an image processing unit 330, a fixing unit 340, an operation panel 350, and a control unit 360. Further, the image forming apparatus 300 is provided with a paper feed tray 390 for cut paper, and the cut paper can be fed from the paper feed tray 390 and printed on the cut paper according to a user's operation input.

The transport unit 310 has a plurality of transport rollers such as a plurality of paper feed transport rollers 311 and a paper discharge transport roller 312. The sheet feeding/conveying rollers 311 are a sheet feeding side conveying mechanism in the image forming apparatus 300, and for example, a pair of rollers that nips the sheet P conveyed from the sheet feeding apparatus 100 and conveys it to the image processing unit 330. Is. On the other hand, the paper discharge transport roller 312 is a transport mechanism on the paper discharge side of the image forming apparatus 300. For example, a pair of rollers that transport the paper P that has passed through the fixing unit 340 to the image inspection device 500 while nipping the paper P. Is. The paper feeding/conveying roller 311 and the paper discharging/conveying roller 312 are driven by a motor (not shown). Further, the transport unit 310 also transports the paper not only in the image forming apparatus 300 but also in the image inspecting apparatus 500 by synchronizing the rotation of each roller 313 in the inspecting apparatus.

The image processing unit 330 forms a toner image by an electrophotographic process and transfers the toner image onto the paper P. Therefore, in the image processing unit 330, a plurality of photosensitive drums (for example, photosensitive drums for Y, M, C, and K) and the intermediate transfer belt 331 are used as image carriers. The intermediate transfer belt 331 is an endless belt, is wound by a plurality of rollers, and is movably supported. The toner images of the respective colors formed on the photosensitive drums Y, M, C, and K are sequentially transferred onto the intermediate transfer belt 331, and the respective colors (Y (Yellow), M (Magenta), C (Cyan), and K (Key). A toner image, which is a color image in which the layers (plate)) are superimposed, is formed on the intermediate transfer belt 331. The intermediate transfer belt 331 and the transfer roller 332 form an image forming nip 333. Then, a bias having a polarity opposite to that of the toner is applied to the transfer roller 332, and the paper P is sandwiched and conveyed by the image forming nip 333, so that the toner image formed on the intermediate transfer belt 331 is transferred onto the paper P. It

The fixing unit 340 fixes the toner image on the sheet P. The fixing unit 340 forms a nip by the fixing belt 341 and the pressure roller 343 by pressing the fixing roller 342, which is a heat source, to the pressure roller 343 via the fixing belt 341. Then, by rotating the fixing roller 342 and the pressure roller 343, the paper P nipped in the nip is conveyed. As a result, the fixing unit 340 applies heat and pressure to the sheet P passing through the fixing unit 340 at the nip to melt and fix the toner image on the sheet P. The fixing roller 342 and the pressure roller 343 are provided so as to be capable of being pressed and separated from each other via the fixing belt 341.

The operation panel 350 includes a touch panel, a numeric keypad, a start button, a stop button, and the like, and is used for displaying various information and inputting various instructions. The display of various information is performed by a command from the control unit 360, and the input is transmitted to the control unit 360.

The control unit 360 controls so that the sheet P from the sheet feeding device 100 is fed out and wound by the sheet discharging device 700 at the time of image formation. FIG. 2 is a block diagram for explaining the control system.

As shown in FIG. 2, the control system is configured such that the control unit 360 is connected to the conveyance unit 310, the image processing unit 330, the fixing unit 340, and the operation panel 350 in the image forming apparatus 300 by a signal line, and the power supply is provided. The paper device 100 and the paper discharge device 700 are also connected by a signal line to control them. Further, the control unit 360 is connected to the first reading unit 511 and the second reading unit 512 (both of which will be described later) of the image inspection apparatus 500 by a signal line, and the first reading unit 511 and the second reading unit 512 read the signals. Receiving image data.

Further, the control unit 360 detects an abnormality in the image formed on the paper P from the image read by the image inspection device 500. Image abnormalities include, for example, image tilt, image positional deviation, image scratches (dirt or missing), and color misregistration. The control unit 360 inspects these abnormal images by comparing the image data read by the image inspection apparatus 500 with the image data of the job input to the image forming system 10. Therefore, the control unit 360 also functions as a part of the image inspection apparatus 500. If the control unit 360 detects an abnormality as a result of the inspection, it displays that there is an image abnormality on the operation panel 350, or transmits the abnormality to another computer. When there is an abnormality in the printed image, control such as stopping the printing operation is also performed.

Further, the control unit 360 detects the foreign matter existing in the first reading unit 511 and/or the second reading unit 512 in the image inspection apparatus 500 from the image read by the image inspection apparatus 500, and the image after the foreign matter detection. Inspection processing is also performed (details will be described later).

The control unit 360 is similar to a general computer, has a CPU 361 (Central Processing Unit), a memory 362, and also has, for example, a network interface. The CPU 361 executes control of the entire image forming system 10 according to a program.

The memory 362 includes a ROM (Read Only Memory) that stores a startup program and a RAM that is a main storage device that is a high-speed access area that temporarily stores programs and data as a work area of the CPU 361. Further, the memory 362 may have a dedicated memory 362 for storing image data or a dedicated area in the RAM. The memory 362 has a storage. The storage is an auxiliary storage device having a sufficient capacity to store various programs including an operating system and various data, for example. The storage is composed of a hard disk or flash memory. The network interface is an interface for communicating with another external device (for example, a client computer in which a printer driver is incorporated) via a computer network, for example. Standards such as Ethernet (registered trademark), Wi-Fi, FDDI (Fiber-distributed data interface), and token ring are used for communication. Since the configuration of such a computer is well known, detailed description will be omitted.

The image inspection apparatus 500 is arranged on the downstream side of the image forming apparatus 300, and reads and inspects an image from the image-formed (printed) paper P inline. For this reason, the image inspection apparatus 500 includes two reading units that read an image from a printed sheet on the conveyance unit 310 (on the conveyance path) in the image inspection apparatus 500. The two reading units are a first reading unit 511 and a second reading unit 512. The first reading unit 511 and the second reading unit 512 have the same configuration. The position where the first reading unit 511 is set on the transport unit 310 is set as a first reading position, and the second reading unit 512 is arranged at a second reading position that is away from the first reading position by a predetermined distance in the sheet transport direction. There is. The predetermined interval may be an interval at which the first reading unit 511 and the second reading unit 512 can be continuously arranged in the sheet conveyance direction.

FIG. 3 is a schematic perspective view for explaining the reading unit. FIG. 4 is a schematic sectional view taken along the line AA of the reading unit shown in FIG. 3 and 4, the image reading surface is shown above the drawings. Further, although the reading unit 520 is shown in the figure, the first reading unit 511 and the second reading unit 512 have the same configuration.

The reading unit 520 has a line image sensor 522, a lens 523, and two light sources 524 inside the housing 521. The line image sensor 522 has a plurality of pixels. The plurality of pixels are arranged side by side in a predetermined direction, and the arrangement direction of the pixels is a direction orthogonal to the transport direction. The pixel arrangement direction may be tilted as long as it covers the direction orthogonal to the paper conveyance direction and can be read as an image. That is, the direction in which the pixels are arranged may be a direction that intersects the transport direction. The lens 523 collects the light reflected from the surface of the conveyed paper on the line image sensor 522. The light source 524 extends in the pixel arrangement direction and irradiates the paper surface with light. A glass 525, which is a transparent member, is fitted into the reading unit 520 on the side of the housing 521 on which the paper is conveyed. The glass 525 protects the inside of the housing 521. In addition, as the transparent member, a transparent resin may be used instead of the glass 525. The reading unit 520 having such a configuration is called a contact image sensor (CIS: Contact Image Sensor).

The reading unit 520 reads the entire sheet by the line image sensor 522 when the sheet is moved (conveyed) on the surface of the glass 525. The image read by the line image sensor 522 is transmitted to the control unit 360.

The first reading unit 511 and the second reading unit 512 thus configured each have the independent glass 525 on the surface on which the paper is conveyed. Therefore, the line image sensor 522 of the first reading unit 511 reads the image through the glass 525 of the first reading unit 511, and the line image sensor 522 of the second reading unit 512 reads the image through the glass 525 of the second reading unit 512.

In this regard, in the related art (Patent Document 1), when reading with a plurality of light receiving sensors through one glass, one foreign substance existing on the glass surface is read with a plurality of light receiving sensors. On the other hand, in the present embodiment, even if there is a foreign substance on the glass surface of either the first reading unit 511 or the second reading unit 512, the foreign substance is read by both the first reading unit 511 and the second reading unit 512. There is no such thing.

The reading unit is not limited to such a contact image sensor configuration. For example, the number of the light source 524 may be one, or the light source 524 may be arranged outside the housing 521. Further, a lens reduction type line image sensor may be used instead of the contact image sensor. Even in that case, the glass to be placed on the reading surface of the sheet is placed independently in each of the first reading unit 511 and the second reading unit 512.

The paper discharge device 700 is a device for discharging the paper P conveyed from the image forming device 300 via the image inspection device 500. In the housing 521 of the paper discharge device 700, for example, the paper P is wound around a support shaft and held in a roll shape. Therefore, the paper discharge device 700 winds the paper P conveyed from the image inspection device 500 around the support shaft at a constant speed via a plurality of rollers (for example, a feeding roller and a paper discharge roller). In the paper discharge device 700, the paper P does not necessarily have to be held in a roll shape, and may be cut page by page. The paper discharge device 700 is provided with a paper discharge adjusting unit 750 between the paper discharge device 700 and the image forming device 300. The paper discharge adjusting unit 750 absorbs the speed difference between the transport speed of the paper P in the image forming apparatus 300 and the winding speed of the paper P in the paper discharge apparatus 700.

Next, the operation of the image inspection device 500 will be described.

The image inspection apparatus 500 is the image inspection apparatus 500 including the control unit 360 in the image forming apparatus 300. The image inspection apparatus 500 of this embodiment has two reading units (first reading unit 511 and second reading unit 512). Therefore, it is preferable to perform image matching in order to eliminate (or reduce) the difference between the image data obtained by the first reading unit 511 and the second reading unit 512.

FIG. 5 is an explanatory diagram for explaining image matching.

For image alignment, for example, the image forming apparatus 300 prints the alignment mark 602 on the paper 600 that is continuous paper outside the area where the image 601 (images A to D in the figure) is printed. The alignment mark 602 is, for example, as shown in FIG. 5, a conveyance direction and a line (cross line) orthogonal to the conveyance direction. With such an alignment mark 602, it is possible to detect the positional deviation in the carrying direction and the positional deviation in the direction orthogonal to the carrying direction.

The control unit 360 superimposes the images read by the first reading unit 511 and the second reading unit 512, and calculates the difference between the alignment marks 602 in the read pixels in the transport direction and the direction orthogonal to the transport direction. Each is extracted, and the position of the image is corrected so that the respective directions of the alignment marks 602 match.

The control unit 360 also detects the line width of the alignment mark 602 from the images read by the first reading unit 511 and the second reading unit 512, and detects the difference in line width. Then, the control unit 360 performs a correction for matching the line widths of the two alignment marks 602 based on the detected line width difference of the alignment marks 602. The line width may be corrected on the thick side or the thin side.

The necessity of performing this line width correction processing will be described. FIG. 6 is an explanatory diagram for explaining the line width correction processing.

For example, as shown in FIG. 6A, when a foreign substance 610 is attached to the surface of the glass 525 of the reading unit, a line 612 appears in the conveyance direction in the image 611 obtained by reading the sheet that has passed therethrough. At this time, if the actual image (actual image 621) has a line 622 in the transport direction as shown in FIG. 6B, the line 612 due to the foreign matter and the line 622 in the actual image 621 overlap as shown in FIG. 6C. there is a possibility. In such a case, if the size of the foreign material 610 and the size of the line 622 in the real image 621 are close (the difference in line width is small), it becomes difficult to determine whether the line 612 is the foreign material-derived line 612 or the real image line 622. On the other hand, such a difference in line width may be a device error between the first reading unit 511 and the second reading unit 512 when the line 622 in the actual image 621 is read. Therefore, in this embodiment, a correction process for matching the line widths is performed. This eliminates the error between the devices. Therefore, if there is a difference in the line width between the images read by the first reading unit 511 and the second reading unit 512, one of them is due to the foreign substance 610, even if the difference in the line width is small. It can be judged as a line. Therefore, the foreign substance detection accuracy is improved.

The image alignment using the alignment mark 602 and the correction of the line width in the image may be performed when the image forming system 10 is assembled, maintenance is performed, or an abnormality occurs. Of course, the user may be allowed to do so. Further, the alignment mark 602 is not limited to the cross line and the number thereof is not limited.

Next, the operation of the image inspection apparatus 500 during image formation will be described. FIG. 7 is a flowchart showing a processing procedure for operating the image inspection apparatus 500. This processing procedure is performed by the control unit 360 executing a program created based on this processing procedure.

When the print job is received and the image forming operation is started, the control unit 360 acquires an image from the first reading unit 511 (S11). The control unit 360 temporarily stores the image acquired here as the first image in the memory 362.

Subsequently, the control unit 360 acquires an image from the second reading unit 512 (S12). The control unit 360 temporarily stores the image acquired here as the second image in the memory 362.

Subsequently, the control unit 360 compares the first image and the second image (S13). At this time, if the excluded pixel is stored in S16, which will be described later, the pixel portion is excluded from the matching target. The part of the image corresponding to the excluded pixel is also excluded in the image inspection after printing.

Subsequently, when the two images match as a result of the matching, the control unit 360 proceeds to S17 as it is, and matches the matched image (either the first image or the second image, or the first image and the second image). Both may be used) and the image data in the job are collated to inspect the image after printing (S17).

On the other hand, when the two images do not match as a result of the matching, the control unit 360 individually matches the two images with the image data in the job (S15). The control unit 360 determines that there is a foreign substance in the reading unit that has acquired the image that does not match the image data in the job by the collation in S15. Then, the control unit 360 stores, in the memory 362, the pixels of the portion that does not match the image data in the job that exists in the image that does not match in the memory 362 (S16). As a result, the control unit 360 excludes the region where the foreign matter exists from the inspection area and does not use it in the subsequent inspections.

Subsequently, when the control unit 360 has passed S16, the control unit 360 compares the first image and the second image of the portion excluding the excluded pixels from the first image or the second image with the image data in the job. The image after printing is inspected (S17).

After that, the control unit 360 determines whether or not the job is completed (S18). If it has ended (S18: YES), this processing ends. On the other hand, if the job has not ended (S18: NO), the process returns to S11 and continues.

According to this embodiment described above, the following effects are achieved.

The image inspection apparatus 500 includes a first reading unit 511 and a second reading unit 512 that read and inspect the same side of a sheet. Then, the same image is read by the first reading unit 511 and the second reading unit 512, the two images are collated, and if there is a difference, foreign matter is attached to either the first reading unit 511 or the second reading unit 512. It was judged that there was a foreign object, and the image was inspected by excluding the pixels in the portion where the foreign matter exists. As a result, even if a foreign substance is present on the surface of the glass 525 of either or both of the first reading unit 511 and the second reading unit 512, the printing operation is not stopped and the image inspection is continuously performed. You can

In particular, continuous paper is used in this embodiment. For continuous paper printing, there is a desire not to stop the image forming system 10 until the job is completed. Therefore, according to the present embodiment, it is not necessary to stop the image forming operation even when foreign matter is present on the surface of the glass 525 of either or both of the first reading unit 511 and the second reading unit 512 during printing on continuous paper. Therefore, the present embodiment can improve productivity in printing on continuous paper. It is also applicable to printing cut sheets. Even in the case of cut sheets, when a plurality of sheets are continuously printed, the image forming operation is stopped even if foreign matter is present on the surface of the glass 525 of either or both of the first reading unit 511 and the second reading unit 512. No need.

Further, when a foreign substance is present, the pixel for reading the image of that portion is set as an exclusion pixel, and the image of that pixel is not used thereafter. Conversely, in other words, the image read by the pixels other than the excluded pixel is used. Then, even if foreign matter exists on the surfaces of the glass 525 of both the first reading unit 511 and the second reading unit 512, it is extremely unlikely that the foreign matter existing positions in the image will be completely the same. An image inspection can be performed using an image read by pixels other than the exclusion pixel in the image.

Although the embodiments have been described above, the present invention is not limited to the embodiments and the modifications. In the embodiment, the control unit 360 of the image forming system 10 executes from the reading of images by the first reading unit 511 and the second reading unit 512 to image collation and image inspection in accordance with the above processing procedure. However, instead of this, for example, a control unit 360 dedicated to the inspection is provided in the image inspection apparatus 500, and the control unit 360 dedicated to the inspection follows the above-described processing procedure and uses the first reading unit 511 and the second reading unit 512. You may make it perform the process from the reading of an image to the collation of an image and the inspection of an image. In this case, the sheet is conveyed in cooperation with the control unit 360 in the image forming system 10. In addition, the image acquired by the image inspection apparatus 500 is fed back to the control unit in the image forming system, and the image is compared with the image data in the job and inspected.

Further, the present invention can be modified in various ways based on the configurations described in the claims, and these are also within the scope of the present invention.

10 image forming system,
100 paper feeders,
300 image forming apparatus,
310 transport section,
330 Image Processing Department,
340 fixing unit,
350 Operation panel,
360 control unit,
500 image inspection equipment,
511 first reading unit,
512 second reading unit,
520 reader,
521 housing,
522 line image sensor,
523 lens,
524 light source,
525 glass,
601 images,
602 alignment mark,
610 foreign matter,
700 paper ejection device.

Claims (14)

In the image inspection device that inspects the image formed on the paper,
A transport unit for transporting the sheet,
A first reading unit which is arranged at a first reading position on the conveying unit and which reads an image of the conveyed sheet;
A second reading unit which is arranged at a second reading position on the carrying unit, which is separated from the first reading position by a predetermined distance in the carrying direction of the paper, and which reads an image on the paper;
Detecting foreign matter adhering to one or both of the first reading unit and the second reading unit from the difference between the first image obtained by the first reading unit and the second image obtained by the second reading unit Control unit to
An image inspection apparatus having: The image inspection apparatus according to claim 1, wherein the first reading unit and the second reading unit each have an independent transparent member on a side where the sheet is conveyed and read an image. The image inspection apparatus according to claim 1, wherein the control unit excludes, when the foreign matter is detected, a region where the foreign matter is detected from the region to be inspected. The image inspection apparatus according to any one of claims 1 to 3, wherein the control unit does not use a region excluded from the region to be inspected for the inspection of subsequent images. The said 1st reading part and the said 2nd reading part are provided in the downstream of the conveyance direction of the said paper rather than the image forming apparatus which forms an image on the said paper, The any one of Claims 1-4. Image inspection device. The image inspection apparatus according to claim 5, wherein the control unit does not stop the operation of the image forming apparatus when the foreign matter is detected. The control unit causes the image forming apparatus to form an alignment mark on a sheet surface outside the image forming area,
The image inspection apparatus according to claim 5, wherein the first image and the second image are aligned with each other using the alignment mark as a reference. The image inspection apparatus according to claim 7, wherein the alignment mark is a line in a conveyance direction of the sheet and a line in a direction intersecting the conveyance direction. The image inspection apparatus according to claim 8, wherein the control unit detects a difference between a line width of the alignment mark in the first image and a line width of the alignment mark in the second image. The controller controls the first image and the second image so that there is no difference between the line width of the alignment mark in the first image and the line width of the alignment mark in the second image. The image inspection apparatus according to claim 9, wherein the line widths of the alignment marks in each of the two are matched. The image inspection apparatus according to claim 5, wherein the first reading unit and the second reading unit read an image formed by the image forming apparatus in-line. The image inspection apparatus according to claim 5, wherein the control unit feeds back one or both of the first image and the second image to the image forming apparatus. The image inspection apparatus according to claim 1, wherein the paper is continuous paper. An image forming apparatus that forms an image on a sheet,
An image inspection apparatus according to any one of claims 1 to 13,
Image forming system having a.