Image reading device and image forming system using said image reading device

Abstract

To reduce a machine size in a sheet conveyance direction.SOLUTION: An image reading device 30 comprises: a conveying unit 40 that conveys a sheet; and a first reading unit (scanner unit 51) that reads an image formed on the sheet. The conveying unit has a first conveying unit 41 that conveys a sheet from an entrance 30a to an exit 30b of the device along a sheet conveyance path 43, and a second conveying unit 42 that conveys a sheet along a bypass path 44 that bypasses part of the sheet conveyance path. The first reading unit is arranged on the sheet conveyance path. A second reading unit (colorimeter 52) different from the first reading unit is arranged on the bypass path.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image reading device and an image forming system using the image reading device. [Background technology]

[0002] Conventionally, there is an image forming system that includes an image forming device such as a printer or a copier that forms an image on a sheet, and an image reading device that reads the image formed by the image forming device, in order to perform image adjustment processing such as image color correction, image formation position adjustment, and image size (magnification) adjustment (see, for example, Patent Document 1). Here, image color correction means optimizing the amount of toner of each color attached to the sheet so that each color of an image formed on the sheet with toner of each color of CMYK (cyan, magenta, yellow, and black) in the image forming device becomes an optimal color. Moreover, image formation position adjustment means adjusting the image formation position so that the image does not become misaligned. Moreover, image size (magnification) adjustment means adjusting the image formation size so that the size of the image formed on the sheet becomes an appropriate size. The image forming system reads the image with the image reading device while forming an image on the sheet on a trial basis, and automatically performs adjustment processing of the image to be formed on the sheet from the next time onward (for example, image color correction, image formation position adjustment, image size (magnification) adjustment, etc.) based on the read image.

[0003] In such a configuration, the image reading device has a scanner unit that reads the entire image formed on the paper, and a colorimeter (spectrophotometer) that measures the color of the image formed on the paper. The role of the scanner unit is to stably read the color of the image for the entire image formed on the paper, and to accurately read the formation position of the image on the paper. The role of the colorimeter is to measure the maximum density value of each color of the image formed on the paper with toner of each color of CMYK in the image forming device.

[0004] The image reading device can perform color correction of the image (optimization of the amount of toner of each color attached to the paper in the image forming device) by measuring the maximum density value (measurement value) of each color of the image with a colorimeter. Also, by measuring the maximum density value (measurement value) of each color of the image with a colorimeter, the image reading device can adjust the sensitivity of the optical sensor (e.g., CCD sensor, etc.) used in the scanner unit to the optimal sensitivity based on the measurement value. This allows the image reading device to use the scanner unit as a color inspection unit that reads the colors of the image formation material (printed material) over a wider range and at higher speed than a colorimeter.

[0005] In addition, the image reading device stores a correct image (correct image information) for inspection processing (processing for determining the quality of an image formed on a sheet) in advance in a storage unit, and can determine (inspect) the quality of an image formed on a sheet by an image forming device by using the correct image. Specifically, the image reading device reads an image formed on a sheet by an image forming device with a scanner unit, and stores the read image (read image information) in a storage unit. Then, the image reading device compares the read image information with the correct image information, obtains a difference between the read image information and the correct image information, and determines (inspects) the quality of the image formed on the sheet from the difference. After this, if the image formed on the sheet is determined to be good (OK), the image reading device conveys the sheet to an exit, and on the other hand, if the image formed on the sheet is determined to be bad (NG), the image reading device switches the conveying direction of the sheet and discharges the sheet to a purge tray.

[0006] Such an image reading device requires time to determine (inspect) whether an image formed on a sheet is good or bad, and time to determine whether the sheet should be discharged to a purge tray and switch the sheet transport direction. Therefore, conventional image reading devices are configured to have a detour path downstream of the scanner unit and the colorimeter to ensure these times. The detour path is provided by branching off from the sheet transport path connecting the entrance and exit of the device. The scanner unit and the colorimeter are disposed on the sheet transport path upstream of the detour path. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2019-54408 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, conventional image reading devices have a bypass path branched off from the paper transport path downstream of the colorimeter, and are configured to selectively pass the paper through the paper transport path or the bypass path after passing the paper through the colorimeter. Since such conventional image reading devices have a bypass path downstream of the colorimeter, the machine size in the paper transport direction (length in the transport direction) is large. Therefore, it has been desired to reduce the machine size in the paper transport direction (length in the transport direction) of conventional image reading devices.

[0009] The present invention has been made in consideration of the problems associated with the above-mentioned conventional technology, and an object of the present invention is to provide an image reading device having a reduced mechanical size in the paper transport direction (length in the transport direction), and an image forming system using the image reading device. [Means for solving the problem]

[0010] The above-mentioned object of the present invention can be achieved by the following means.

[0011] (1) An image reading device comprising: a paper transport path along which paper on which an image is formed is transported; a detour path that branches off from the paper transport path and joins the paper transport path downstream of the branching point in the paper transport direction on the paper transport path, and along which paper is transported in one direction from the branching point to the joining point; a first reading unit that is disposed upstream of the branching point in the paper transport direction with respect to the paper transport path and reads the image formed on the paper; and a second reading unit that is disposed on the detour path and reads the image formed on the paper. The detour path has a straight horizontal portion, and the second reading unit is disposed on the horizontal portion. , image reading device.

[0012] (2) The image reading device according to (1) above, wherein the paper transport path is formed in a straight line.

[0013] (3) The image reading device according to (1) above, wherein the length of the detour path is longer than the length of the paper transport path from the point where the detour path branches off from the paper transport path to the point where the detour path joins.

[0015] ( 4 ) The image reading device described in (1) above, wherein the detour path is disposed below the paper transport path, and the horizontal portion is provided at a lower end portion of the detour path.

[0016] ( 5 2. The image reading device according to claim 1, wherein a sheet of paper whose image is to be read by the first reading unit is transported along the same detour path as a sheet of paper whose image is to be read by the second reading unit.

[0017] ( 6 ) The image reading device described in (1) above, wherein the first reading unit has a first scanner that reads an image formed on the back side of the paper, and a second scanner that reads an image formed on the front side of the paper.

[0018] ( 7 ) the second scanner is disposed downstream of the first scanner in the paper transport direction, 6 ) An image reading apparatus according to the present invention.

[0019] ( 8 2. The image reading device according to claim 1, wherein the second reading unit is a colorimeter for measuring the color of an image. ( 9 ) a paper transport path along which paper on which an image is formed is transported; a detour path which branches off from the paper transport path and joins the paper transport path downstream of the branching point in the paper transport direction on the paper transport path, and along which paper is transported in one direction from the branching point to the joining point; a first reading unit which is disposed upstream of the branching point in the paper transport direction with respect to the paper transport path and reads the image formed on the paper; and a second reading unit which is disposed relative to the detour path and reads the image formed on the paper, wherein the second reading unit is a colorimeter for measuring the color of the image, The sensitivity of the optical sensor used in the first reading unit is adjusted based on color measurement information obtained by measuring the color measurement image formed on the paper transported to the bypass path with the colorimeter. , painting Image reading device. ( 10 ) the conveying speed of the paper conveyed through the detour path when the color of the image is measured by the colorimeter is slower than the conveying speed of the paper conveyed through the paper conveying path,8 ) An image reading apparatus according to the present invention. ( 11 ) a paper transport path along which paper on which an image is formed is transported; a detour path which branches off from the paper transport path and joins the paper transport path downstream of the branching point in the paper transport direction on the paper transport path, and along which paper is transported in one direction from the branching point to the joining point; a first reading unit which is disposed upstream of the branching point in the paper transport direction with respect to the paper transport path and reads the image formed on the paper; and a second reading unit which is disposed relative to the detour path and reads the image formed on the paper, A path length from the first reading unit to the second reading unit is formed longer than a length in a conveying direction of a sheet of paper on which an image is read by the second reading unit. , painting Image reading device.

[0020] ( 12 a paper transport path along which the paper on which the image has been formed by the image forming unit is transported; a detour path which branches off from the paper transport path and joins the paper transport path downstream in the paper transport direction of the paper transport path from the branching point, and along which the paper is transported in one direction from the branching point to the joining point; a first reading unit which is disposed upstream in the paper transport direction of the paper transport path from the branching point, and reads the image formed on the paper; and a second reading unit which is disposed on the detour path and reads the image formed on the paper. The detour path has a straight horizontal portion, and the second reading unit is disposed on the horizontal portion. , image forming system. ( 13 ) the position of the image formed by the image forming unit is adjusted based on the read image information acquired by reading the first reading unit, 12 ) An image forming system according to the present invention 。 ( 14 ) the paper transport path along which the paper on which the image has been formed by the image forming unit is transported; a bypass path which branches off from the paper transport path and joins with the paper transport path downstream in the paper transport direction of the paper transport path from the branching point, and along which the paper is transported in one direction from the branching point to the joining point; a first reading unit which is disposed upstream in the paper transport direction of the paper transport path from the branching point, and reads the image formed on the paper; and a second reading unit which is disposed relative to the bypass path, and reads the image formed on the paper; A size of an image formed by the image forming unit is adjusted based on read image information acquired by reading the first reading unit. , painting Imaging system. ( 15 ) The quality of the image formed on the paper is judged based on the read image information acquired by the reading of the first reading unit. 12 ) An image forming system according to the present invention. ( 16 ) the paper after passing through the first reading unit is sent to the detour path, and the quality of the image is judged while the paper is passing through the detour path. 15 ) An image forming system according to the present invention. ( 17) the paper on which an image determined to be defective is formed is discharged to a purge tray different from the output unit of the paper on which an image determined to be good is formed, 15 ) An image forming system according to the present invention. ( 18 ) the second reading unit is a colorimeter for measuring the color of an image, 12 ) An image forming system according to the present invention. ( 19 ) performing color correction of an image formed by the image forming unit based on color measurement information obtained by measuring the color measurement image formed on the paper transported to the bypass path by the colorimeter; 18 ) An image forming system according to the present invention. Effect of the Invention

[0021] According to the present invention, the machine size in the paper transport direction (length in the transport direction) can be reduced. [Brief description of the drawings]

[0022] [Figure 1] 1 is a schematic diagram showing the overall configuration of an image forming system including an image reading apparatus according to an embodiment; [Diagram 2] 1 is a block diagram showing an internal configuration of an entire image forming system including an image reading apparatus according to an embodiment; [Diagram 3] FIG. 2 is an explanatory diagram illustrating the configuration and operation of an image reading device. [Figure 4] FIG. 2 is an explanatory diagram showing the operation of the image reading device. [Diagram 5] 4 is a flowchart showing the operation of the image reading apparatus. [Figure 6] FIG. 1 is a schematic diagram illustrating a configuration of an image reading device of a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that each drawing is merely a schematic illustration to allow a sufficient understanding of the present invention. Therefore, the present invention is not limited to the illustrated examples. In addition, in each drawing, common or similar components are given the same reference numerals, and duplicated explanations thereof will be omitted.

[0024] <Image forming system configuration> Hereinafter, the configuration of an image forming system 100 including an image reading device 30 according to an embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram showing the overall configuration of the image forming system 100. Figure 2 is a block diagram showing the internal configuration of the entire image forming system 100. Here, the description will be given assuming that the image forming device 20 is a printer that forms an image by an electrophotographic process.

[0025] In the following description, the terms "upstream side" and "downstream side" are based on the transport direction of the paper.

[0026] 1, the image forming system 100 includes a paper feeder 10 that supplies paper to an image forming apparatus 20, an image forming apparatus 20 that forms an image on the paper, and an image reading apparatus 30 that reads the image formed on the paper. The paper feeder 10, the image forming apparatus 20, and the image reading apparatus 30 are arranged in order from the upstream side to the downstream side.

[0027] The image forming apparatus 20 has a control unit 21, a transport unit 24, an image forming unit 25, and a fixing unit 26. The control unit 21 controls the operation of the entire image forming apparatus 20. The transport unit 24 transports the paper supplied from the paper feeder 10 toward the image reading device 30. The image forming unit 25 forms an image on the paper by attaching toner (developer) to the paper. The fixing unit 26 applies heat and pressure to the image formed on the paper to fix the image to the paper.

[0028] A path for transporting paper by a guide or the like (hereinafter, may be referred to as a "transport path") is formed inside the image reading device 30. This transport path is configured to include a paper transport path 43, a bypass path 44, and a purge path 45.

[0029] Paper transport path 43 is formed so as to connect between entrance 30a and exit 30b of image reading device 30. In the example shown in FIG. 1, paper transport path 43 is formed in a substantially straight line. However, the shape of paper transport path 43 is not limited to a straight line. For example, paper transport path 43 may be formed so as to be inclined obliquely. Or, paper transport path 43 may be formed so as to be curved. Or, paper transport path 43 may be formed so as to have a plurality of steps.

[0030] The detour path 44 is formed so as to detour around a part of the paper transport path 43 (in the example shown in FIG. 1, the part from the branch point P43a to the joint point P43b). Specifically, the detour path 44 is formed so as to branch off from the paper transport path 43 at the branch point P43a, pass under the paper transport path 43, and join the paper transport path 43 at the joint point P43b. The detour path 44 is formed longer than the detoured part of the paper transport path 43 (in the example shown in FIG. 1, the part from the branch point P43a to the joint point P43b). In the example shown in FIG. 1, the detour path 44 has an inclined portion 44a and a horizontal portion 44b. The inclined portion 44a is provided in the detour path 44 between the branch point P43a and the horizontal portion 44b, and is a linear portion formed so as to be inclined obliquely. The horizontal portion 44b is provided in the detour path 44 at the lower end portion of the detour path 44, and is a linear portion formed in the horizontal direction. In the example shown in FIG. 1, a colorimeter 52 (second reading unit) described later is disposed on the horizontal portion 44b of the detour path 44.

[0031] The purge path 45 is formed so as to connect the joint P43b and the purge tray 49. The purge tray 49 is a place where the paper to be discarded is discharged. The purge tray 49 is provided in a place different from the outlet 30b. Note that the "paper to be discarded" is, for example, paper on which a defective image is formed (defective product), paper used for adjusting the sensitivity of an optical sensor (e.g., a CCD sensor or the like) used in the scanner unit 51 (first reading unit) (paper used for adjusting the sensitivity of the scanner unit 51), paper used for color correction of an image formed on the paper, etc.

[0032] The image reading device 30 includes a control unit 31, a conveying unit 40, conveying path switching units 46, 47a, and 47b, a scanner unit 51 as a first reading unit, and a colorimeter 52 as a second reading unit.

[0033] The control unit 31 controls the overall operation of the image reading device 30 . The conveying section 40 is composed of rollers (not shown) and motors for driving the rollers, and conveys the paper along the conveying path. For example, the conveying section 40 takes in the paper supplied from the image forming device 20 from the entrance 30a and conveys it toward the exit 30b. The conveying section 40 has a first conveying section 41 that conveys the paper from the entrance 30a to the exit 30b of the image reading device 30 along the paper conveying path 43, and a second conveying section 42 that conveys the paper along a bypass path 44. Note that in this embodiment, the description will be given assuming that an output section 48 for accumulating the paper is disposed at the exit 30b. However, instead of the output section 48, a post-processing device (not shown) for cutting the paper into a predetermined size, for example, may be disposed at the exit 30b of the image reading device 30.

[0034] The conveying path switching units 46, 47a, 47b are composed of blade members (not shown) and motors for driving the blade members, and switch the conveying direction of the paper. The conveying path switching unit 46 is provided in a position upstream of the branch point P43a on the paper conveying path 43, and switches the conveying direction of the paper to the direction of the outlet 30b or the direction of the detour path 44. The conveying path switching unit 47a is provided in a position upstream of the joint point P43b on the paper conveying path 43, and switches the conveying direction of the paper to the direction of the outlet 30b or the direction of the purge tray 49. The conveying path switching unit 47b is provided in a position upstream of the joint point P43b on the detour path 44, and switches the conveying direction of the paper to the direction of the purge tray 49 or the direction of the outlet 30b.

[0035] The scanner unit 51 (first reading unit) reads the entire image formed on the paper. In this embodiment, the scanner unit 51 has a first scanner 51a that reads the image formed on the back side of the paper, and a second scanner 51b that reads the image formed on the front side of the paper. The second scanner 51b is disposed downstream of the first scanner 51a. Note that in this embodiment, the first scanner 51a and the second scanner 51b are described as having reflective optical sensors. The optical sensors are composed of, for example, CCD sensors.

[0036] The colorimeter 52 (second reading unit) reads (measures) the color of the image formed on the paper. The colorimeter 52 (second reading unit) is disposed on the bypass path 44 downstream of the second scanner 51b of the scanner unit 51 (first reading unit).

[0037] Here, the structural features of the image reading device 30 according to the present embodiment will be described by comparing the image reading device 130 of the comparative example shown in Fig. 6 with the image reading device 30 according to the present embodiment shown in Fig. 1. Fig. 6 is a schematic diagram showing the configuration of the image reading device 130 of the comparative example.

[0038] The image reading device 130 of the comparative example (see FIG. 6) corresponds to a conventional image reading device. The image reading device 130 of the comparative example is structured such that a colorimeter 52 (second reading unit) is disposed between the second scanner 51b of the scanner unit 51 (first reading unit) on the paper transport path 43 and the branch point P43a. The image reading device 130 of the comparative example has a detour path 44 that is provided by branching off from the paper transport path 43 downstream of the colorimeter 52 (second reading unit). The image reading device 130 of the comparative example is structured such that, regardless of whether or not color measurement processing is performed, after passing a paper through the paper transport path 43 and passing the paper through the colorimeter 52 (second reading unit), the transport direction of the paper is selected to be a direction that maintains the paper transport path 43 or a direction that switches to the detour path 44. In the image reading device 130 of the comparative example, when adjusting the sensitivity of the scanner unit 51 or when correcting the color of an image, the colorimeter 52 (second reading unit) measures the color of the paper while the paper is being conveyed on the paper conveying path 43, so that the colorimeter 52 (second reading unit) can perform good color measurement. At that time, the image reading device 130 of the comparative example ensures a relatively long distance between the second scanner 51b of the scanner unit 51 (first reading unit) and the branch point P43a, and sets the conveying speed of the first conveying unit 41 to a relatively slow speed, so that the image reading device 130 of the comparative example has a detour path 44 downstream of the colorimeter 52 (second reading unit) and ensures a relatively long distance between the second scanner 51b of the scanner unit 51 (first reading unit) and the branch point P43a, so that the horizontal distance L130a from the second scanner 51b of the scanner unit 51 (first reading unit) to the exit 30b becomes relatively large. Therefore, the image reading device 130 of the comparative example is structured such that the machine size L130 (length in the conveying direction) in the conveying direction of the paper is relatively large. Also, the image reading device 130 of the comparative example sets the conveying speed of the first conveying unit 41 to a relatively slow speed during color measurement such as sensitivity adjustment of the scanner unit 51 and color correction of the image. Therefore, the image reading device 130 of the comparative example is structured such that a relatively long processing time is required during color measurement.

[0039] In contrast, the image reading device 30 (see FIG. 1) according to this embodiment is structured such that a colorimeter 52 (second reading unit) is disposed in a linear portion (horizontal portion 44b in the example shown in FIG. 1) formed in the detour path 44. The image reading device 30 according to this embodiment is structured such that, when performing color measurement processing, the paper is passed through the paper transport path 43 and then the transport direction of the paper is switched to the direction of the detour path 44, while, when not performing color measurement processing, the paper is passed through the paper transport path 43 and then the transport direction of the paper is maintained in the direction of the paper transport path 43. Note that, when performing color measurement processing, for example, sensitivity adjustment of the scanner unit 51 or color correction of an image is performed. When performing color measurement processing, the image reading device 30 according to this embodiment performs color measurement with the colorimeter 52 (second reading unit) while the paper is being transported on the detour path 44. The image reading device 30 according to this embodiment has a detour path 44 in the vicinity of the downstream side of the second scanner 51b of the scanner unit 51 (first reading unit), and a colorimeter 52 (second reading unit) is arranged on the detour path 44. Therefore, the image reading device 30 according to this embodiment does not need to secure a relatively long distance between the second scanner 51b of the scanner unit 51 (first reading unit) and the branch point P43a. Furthermore, the image reading device 30 according to this embodiment does not need to set the conveying speed of the first conveying unit 41 to a relatively low speed. The image reading device 30 according to this embodiment can make the horizontal distance L30a from the second scanner 51b of the scanner unit 51 (first reading unit) to the exit 30b shorter than the distance L130a of the image reading device 130 of the comparative example. Therefore, the image reading device 30 according to this embodiment can reduce the machine size L30 (length in the conveying direction) in the paper conveying direction compared to the machine size L130 (length in the conveying direction) of the image reading device 130 of the comparative example. Furthermore, in the image reading device 30 according to this embodiment, the conveying speed of the first conveying unit 41 is not related to the accuracy of the color measurement performed by the colorimeter 52 (second reading unit) during color measurement, so the conveying speed of the first conveying unit 41 can be made faster than that of the image reading device 130 of the comparative example. Therefore, the image reading device 30 according to this embodiment can shorten the processing time during color measurement.

[0040] 2, the image forming apparatus 20 includes the above-mentioned control unit 21, conveying unit 24, image forming unit 25, and fixing unit 26, as well as a storage unit 22 and a communication unit 23. The storage unit 22 stores a control program that defines the operation of the image forming apparatus 20, various setting information related to image formation (such as information on the paper conveying speed and the amount of toner supplied), and job data for image formation instructed from an external device. The communication unit 23 communicates with other devices (external devices, paper feeder 10, image reader 30, etc.).

[0041] The image reading device 30 includes the above-mentioned control unit 31, the conveying unit 40, the conveying path switching units 46, 47a, 47b, the scanner unit 51 (first reading unit), and the colorimeter 52 (second reading unit), as well as a storage unit 32 and a communication unit 35. The storage unit 32 stores a control program that prescribes the operation of the image reading device 30, various setting information related to image reading (e.g., information on the conveying speed of paper and the timing of switching the conveying path), information on the read image (read image information), and discrimination result information on the read image. The communication unit 35 communicates with another device (in this embodiment, the image forming device 20).

[0042] The control unit 31 includes a transport control unit 31a, a reading control unit 31b, a quality determination unit 31c, and an adjustment unit 31d. The transport control unit 31a controls the operation of the transport unit 40, transport path switching units 46, 47a, and 47b, and other units related to transport of paper. The reading control unit 31b controls the operations of the scanner unit 51 (first reading unit), the colorimeter 52 (second reading unit), and other units involved in reading an image formed on a sheet of paper. The quality determining section 31c determines whether the image formed on the paper is good or bad. The adjustment unit 31d adjusts the image formed on the paper. For example, the adjustment unit 31d adjusts the image formation position and the image size (magnification) based on the read image information acquired by the scanner unit 51 (first reading unit). The adjustment unit 31d also corrects the color of the image based on the color measurement value information acquired by the colorimeter 52 (second reading unit).

[0043] 3, the image reading device 30 is configured such that the distance Lr from the second scanner 51b of the scanner unit 51 (first reading unit) to the colorimeter 52 (second reading unit) is longer than the length Lm in the conveying direction of the paper m used during color measurement (Lr>Lm). Also, the image reading device 30 is configured such that the conveying speed SP42 of the second conveying unit 42 is slower than the conveying speed SP41 of the first conveying unit 41 during color measurement.

[0044] During the paper inspection process described below (processing for determining the quality of the image formed on the paper), the image reading device 30 determines the quality of the image formed on the paper m using the quality determination section 31c while the paper m is passing through the bypass path 44. The image reading device 30 conveys the paper on which the proper image is formed (non-defective product) to the exit 30b and accumulates it in the output section . Further, the image reading device 30 conveys paper on which a defective image is formed (defective product) and paper used for color measurement (paper used for color measurement) to a purge tray 49 and accumulates them on the purge tray 49.

[0045] 4, the image reading device 30 passes a first sheet of paper m1 through the second conveying section 42 and measures the image on the sheet m1 with a colorimeter 52 (second reading section), while passing a second sheet of paper m2 through the first conveying section 41 and reading the image on the sheet m1 with a scanner section 51 (first reading section). Then, the image reading device 30 adjusts the image based on the information acquired by the scanner section 51 (first reading section). For example, the image reading device 30 adjusts the image formation position and adjusts the image size (magnification) based on the read image information acquired by the scanner section 51 (first reading section).

[0046] <Operation of the image forming system> Hereinafter, the operation of the image forming system 100 will be described with reference to FIG.

[0047] The image forming system 100 starts operation by, for example, acquiring job data instructing image formation from an external device. In this embodiment, the image forming system 100 will be described as performing color measurement processing and color correction of an image formed by the image forming apparatus 20 before performing image formation based on the job data.

[0048] As shown in FIG. 5, the control unit 21 of the image forming apparatus 20 of the image forming system 100 determines whether or not there is a color measurement process (step S105).

[0049] When it is determined in step S105 that color measurement processing is to be performed (if "Yes"), the image forming apparatus 20 forms a test image for color measurement on a sheet (test print) (step S106) and sends the sheet to the image reading apparatus 30. Then, the control unit 21 of the image forming apparatus 20 notifies the image reading apparatus 30 that color measurement processing is to be performed. In response to this, the image reading apparatus 30 passes the sheet sent from the image forming apparatus 20 through the first conveying unit 41 to the second conveying unit 42 (step S110). Then, the image reading apparatus 30 measures the image formed on the sheet with the colorimeter 52 (second reading unit) (step S115). At this time, the image reading apparatus 30 measures the maximum density value of the image formed on the sheet with the toner of each color of CMYK (cyan, magenta, yellow, black) with the colorimeter 52 (second reading unit) and acquires the colorimetric value (colorimetric value information) of each color. Then, the image reading device 30 conveys the paper whose color has been measured to the purge tray 49 and ejects it onto the purge tray 49 (step S120).

[0050] The colorimetric value information acquired in step S115 is used to adjust the sensitivity of an optical sensor (e.g., a CCD sensor) used in the scanner section, and to correct the color of an image formed in the image forming unit 25 of the image forming apparatus 20. Here, a description will be given assuming that the colorimetric value information acquired in step S115 is used for color correction of an image formed in the image forming unit 25 of the image forming apparatus 20.

[0051] After step S120, the control unit 31 of the image reading device 30 determines whether or not color correction of the image formed on the paper is necessary based on the color measurement value information acquired in step S115 (step S125).

[0052] When it is determined in step S125 that color correction of the image is necessary (in the case of "Yes"), the control unit 31 of the image reading device 30 performs color correction of the image in the adjustment unit 31d based on the color measurement value information acquired in step S115. Specifically, the control unit 31 calculates a color correction value of the image in the adjustment unit 31d, and feeds back the correction value (color correction value information) of the color of the image to the image forming device 20 (step S130). As a result, the control unit 31 instructs the image forming device 20 to perform color correction of the image. In response to this, the control unit 21 of the image forming device 20 changes the color setting of the image formed on the paper based on the color correction value information of the image. Note that the processes of steps S125 and S130 can be performed by the control unit 21 of the image forming device 20 by the image reading device 30 outputting the color measurement value information acquired in step S115 to the image forming device 20.

[0053] On the other hand, if it is determined in step S125 that color correction of the image is not necessary ("No"), the image forming device 20 starts forming an image based on the job data acquired from the external device (step S135) and sends the paper to the image reading device 30.

[0054] After step S135, the control unit 21 of the image forming apparatus 20 determines whether or not there is an inspection process for the paper on which the image was formed in step S135 (a process for determining the quality of the image formed on the paper) (step S140).

[0055] If it is determined in step S140 that inspection processing is to be performed (if "Yes"), the control unit 21 of the image forming device 20 notifies the control unit 31 of the image reading device 30 that inspection processing is to be performed. In response to this, the image reading device 30 passes the paper sent from the image forming device 20 through the first conveying unit 41 (step S145). At that time, the image reading device 30 reads the image formed on the paper with the scanner unit 51 (first reading unit) and obtains the read image (read image information) (step S150).

[0056] After step S150, the image reading device 30 passes the paper through the second transport section 42 (step S152). After step S152, the image reading device 30 performs processes from step S155 to step S165 described below while the paper is passing through the detour path 44. Note that the correct image (correct image information) is stored in the memory section 32 of the image reading device 30 at any time.

[0057] First, the control unit 31 of the image reading device 30 compares the read image (read image information) acquired in step S150 with the correct image (correct image information) stored in the storage unit 32 to acquire the difference (difference information) between the read image and the correct image (step S155). Then, the control unit 31 of the image reading device 30 performs an inspection process of the paper on which the image is formed in step S135, that is, a judgment (inspection) process of whether the image formed on the paper is good or bad based on the difference (step S160).

[0058] After step S160, the control unit 31 of the image reading device 30 judges whether or not there are any defective products (paper sheets on which a defective image is formed) in the inspection process (step S165). If it is judged in step S165 that there are any defective products (if "Yes"), the image reading device 30 transports the defective products to the purge tray 49 and discharges them onto the purge tray 49 (step S170). On the other hand, if it is judged in step S165 that there are no defective products (if "No"), the image reading device 30 transports non-defective products (paper sheets on which a good image is formed) to the exit 30b and accumulates them in the output unit 48 (step S175).

[0059] After step S170 or step S175, the control unit 31 of the image reading device 30 determines whether image formation for all jobs has been completed (step S180). If it is determined in step S180 that image formation for all jobs has not been completed (if "No"), the process returns to step S145. On the other hand, if it is determined in step S180 that image formation for all jobs has been completed (if "Yes"), the process of the series of routines ends.

[0060] If it is determined in the above-mentioned step S140 that the inspection process is not performed (if "No"), the image reading device 30 passes the paper through the first conveying section 41 (step S185). Then, the image reading device 30 conveys the paper to the exit 30b and accumulates it in the output section 48 without performing the inspection process on the paper (step S190).

[0061] After step S190, the control unit 31 of the image reading device 30 determines whether image formation for all jobs has been completed (step S195). If it is determined in step S195 that image formation for all jobs has not been completed (if "No"), the process returns to step S185. On the other hand, if it is determined in step S195 that image formation for all jobs has been completed (if "Yes"), the process of the series of routines ends.

[0062] <Main features of the image reader> The main features of the image reading device 30 will now be described.

[0063] (1) As shown in Fig. 1, the image reading device 30 according to this embodiment includes a transport section 40 that transports paper and a scanner section 51 as a first reading section that reads an image formed on the paper. The transport section 40 includes a first transport section 41 that transports paper along a paper transport path 43 from an entrance 30a to an exit 30b of the image reading device 30, and a second transport section 42 that transports paper along a detour path 44 that detours around a part of the paper transport path 43 (in the example shown in Fig. 1, the part from the branch point P43a to the joint point P43b). The paper transport path 43 includes a scanner section 51 (first reading section) disposed upstream of the detour path 44. The detour path 44 includes a colorimeter 52 as a second reading section separate from the scanner section 51 (first reading section).

[0064] The image reading device 30 according to this embodiment has a detour path 44 downstream of the scanner unit 51 (first reading unit), and a colorimeter 52 (second reading unit) is disposed in the detour path 44. Therefore, the image reading device 30 according to this embodiment does not need to secure a relatively long distance between the second scanner 51b of the scanner unit 51 (first reading unit) and the branch point P43a. The image reading device 30 according to this embodiment can reduce the machine size L30 (shown in FIG. 1) in the paper transport direction.

[0065] (2) As shown in step S145 of FIG. 5, the second conveying section 42 of the image reading device 30 according to the present embodiment is used when judging the quality of the image formed on the paper.

[0066] When judging the quality of an image formed on a sheet (if the judgement is "Yes" in step S140 in FIG. 5), the image reading device 30 according to this embodiment passes the sheet through the sheet transport path 43 and then switches the sheet transport direction to the bypass path 44. On the other hand, when not judging the quality of an image (if the judgement is "No" in step S140 in FIG. 5), the image reading device 30 according to this embodiment maintains the sheet transport direction along the sheet transport path 43. In the image reading device 30 according to this embodiment, the transport speed of the first transport section 41 is not related to the accuracy of color measurement performed by the colorimeter 52 (second reading section), so that the transport speed of the first transport section 41 can be made relatively high.

[0067] (3) The scanner unit 51 (first reading unit) of the image reading device 30 in this embodiment has a function of reading the entire image formed on paper, and the colorimeter 52 (second reading unit) is configured to have a function of measuring the color of the image formed on paper.

[0068] The image reading device 30 according to this embodiment can adjust the image formation position, adjust the image size (magnification), etc., based on the read image information acquired by the scanner unit 51 (first reading unit). Also, the image reading device 30 according to this embodiment can perform color correction of the image based on the color measurement value information acquired by the colorimeter 52 (second reading unit).

[0069] (4) As shown in FIG. 1, the reading surface of the colorimeter 52 (second reading unit) of the image reading device 30 in this embodiment may be arranged in a linear portion (e.g., the inclined portion 44a or the horizontal portion 44b) formed in the bypass path 44.

[0070] The image reading device 30 according to this embodiment can stably measure the maximum density value (measured value) of each color in an image.

[0071] (5) As shown in FIG. 3, the conveying speed SP42 of the second conveying section 42 of the image reading device 30 according to this embodiment is slower than the conveying speed SP41 of the first conveying section 41 (SP42 <SP41)とよい。

[0072] The image reading device 30 according to this embodiment sets the conveying speed SP42 (see FIG. 3) of the second conveying unit 42, which is related to the accuracy of the color measurement performed by the colorimeter 52 (second reading unit), to be slower than the conveying speed SP41 (see FIG. 3) of the first conveying unit 41, which is not related to the accuracy of the color measurement. Since the image reading device 30 according to this embodiment can perform good color measurement, it is possible to suppress failures in the color measurement process, reduce the size of patch data due to failures in the color measurement process, and reduce the amount of paper wasted due to failures in the color measurement process.

[0073] (6) As shown in FIG. 3, the distance Lr from the scanner unit 51 (first reading unit) to the colorimeter 52 (second reading unit) of the image reading device 30 in this embodiment is preferably longer than the length Lm of the paper used during color measurement.

[0074] In the image reading device 30 according to this embodiment, the distance Lr (see FIG. 3) is longer than the length Lm (see FIG. 3), so that the rear end of the paper does not remain on the paper transport path 43 when the leading end of the paper reaches the colorimeter 52 (second reading unit). Furthermore, the image reading device 30 according to this embodiment can ensure sufficient time during color measurement to perform any processing based on the colorimetric value information while the paper is being transported on the detour path 44 by the second transport unit 42 (for example, time to determine whether color correction of the image formed on the paper is necessary).

[0075] (7) As shown in Fig. 1, the image reading device 30 according to the present embodiment may be configured to include a quality determination unit 31c that determines the quality of an image formed on a sheet based on a difference between a read image read by the scanner unit 51 (first reading unit) and a previously prepared correct image, and a discrimination means that distinguishes sheets (defective products) on which an image determined to be defective by the quality determination unit 31c is formed. In the example shown in Fig. 1, the transport path switching units 47a and 47b function as the discrimination means.

[0076] The image reading device 30 according to this embodiment distinguishes defective sheets from other sheets, and therefore can prevent non-defective sheets from being mixed with defective sheets.

[0077] (8) As shown in FIG. 3, the quality determination unit 31c of the image reading device 30 according to this embodiment may be configured to determine the quality of the image formed on the paper while the paper is passing through the bypass path 44.

[0078] The image reading device 30 according to this embodiment determines the quality of the image while the paper is passing through the bypass path 44, and can select the output section 48 or the purge tray 49 as the destination for the paper before the leading edge of the paper reaches the rear end of the bypass path 44.

[0079] (9) As shown in FIG. 1, the conveying section 40 of the image reading device 30 according to this embodiment may be configured to discharge paper (defective product) on which an image that has been determined to be defective by the pass / fail judgment section 31c (see FIG. 2) is formed to a purge tray 49.

[0080] The image reading device 30 according to this embodiment can reliably separate non-defective products from defective products. Also, the image reading device 30 according to this embodiment can collect defective products on the purge tray 49 and discard them all at once.

[0081] (10) As shown in FIG. 1, the conveying section 40 of the image reading device 30 according to this embodiment may be configured to eject the paper used when measuring the color of an image with the colorimeter 52 (second reading section) to a purge tray 49.

[0082] The image reading device 30 according to this embodiment can prevent the paper used for color measurement from being mixed with the printed matter (image-formed matter) even when color measurement is performed during printing.

[0083] (11) As shown in Fig. 4, the image reading device 30 according to this embodiment may be configured to pass a sheet of paper m2 through the first conveying section 41 and adjust the image based on information acquired by the scanner section 51 (first reading section) while passing a sheet of paper m1 through the second conveying section 42 and measuring the color of the image with a colorimeter 52 (second reading section). Note that image adjustment based on information acquired by the scanner section 51 (first reading section) includes, for example, adjusting the image formation position, adjusting the image size (magnification), etc.

[0084] The image reading device 30 according to this embodiment can perform other adjustments while measuring the color of the paper m1.

[0085] As described above, according to the image reading device 30 of the embodiment, since the colorimeter 52 is arranged on the bypass path 44, the machine size (length in the transport direction) in the paper transport direction can be reduced (made compact).

[0086] The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the gist of the present invention.

[0087] For example, the above-described embodiment has been described in detail to clearly explain the gist of the present invention. Therefore, the present invention is not necessarily limited to having all of the components described. In addition, the present invention can be modified by adding other components to certain components, or by replacing some components with other components. In addition, the present invention can be modified by deleting some components.

[0088] For example, in the embodiment described above, the adjustment unit 31d that adjusts the image formed on the paper is provided in the control unit 31 of the image reading device 30. However, the adjustment unit 31d may be provided in the control unit 21 of the image forming device 20.

[0089] Also, for example, in the above-described embodiment, the distinguishing means for distinguishing the paper on which the image determined to be defective by the defective / defective determining unit 31c is formed is configured as the transport path switching units 47a and 47b. However, the distinguishing means can be configured in other forms. For example, the distinguishing means can be configured as an identification mark forming unit (not shown) that forms an identifiable mark on the paper on which the image determined to be defective is formed. Or, the distinguishing means can be configured as a notch forming unit (not shown) that forms a notch portion (partially cut portion) on the paper on which the image determined to be defective is formed. Or, the distinguishing means can be configured as a sticky note pasting unit (not shown) that pastes a sticky note on the paper on which the image determined to be defective is formed. [Explanation of symbols]

[0090] 10 Paper feeder 20 Image forming device 21 Control section 22 Memory section 23 Communications Department 24 Conveyor 25 Image forming section 26 Fixing section 30 Image reader 30a entrance 30b exit 31 Control Unit 31a Transport control section 31b Reading control unit 31c Quality Judgment Section 31d Adjustment section 32 Storage section 33 Communications Department 40 Conveyor 41 First conveyor section 42 Second conveyor section 43 Paper transport path 44 Detour Route 44a Inclined section (straight section) 44b Horizontal section (straight section) 45 Purge Path 46 Conveyor path switching section 47a, 47b Conveying path switching unit (distinguishing means) 48 Output section 49 Purge Tray 51 Scanner unit (first reading unit) 51a 1st scanner 51b Second scanner 52 Colorimeter (second reading unit) 100 Image forming system SP41 conveying speed SP42 conveying speed L30 Machine size L30a distance Lm Length Lr Distance m,m1,m2 paper P43a Branch point P43b Joint

Claims

1. a paper transport path along which paper on which an image is formed is transported; a bypass path that branches off from the paper transport path and joins the paper transport path downstream of the branch point in the paper transport direction of the paper transport path, and through which paper is transported in one direction from the branch point to the joining point; a first reading unit that is disposed on the upstream side of the branch point in the paper transport direction with respect to the paper transport path and that reads an image formed on the paper; a second reading unit that is disposed with respect to the bypass path and reads an image formed on a sheet of paper; the bypass path has a straight horizontal portion, and the second reading unit is disposed on the horizontal portion; Image reading device.

2. The paper transport path is formed in a straight line.

2. The image reading device according to claim 1.

3. The length of the detour path is formed to be longer than the length of the paper transport path from the point where the detour path branches off from the paper transport path to the joining point.

2. The image reading device according to claim 1.

4. the bypass path is disposed below the paper transport path, and the horizontal portion is provided at a lower end portion of the bypass path; 2. The image reading device according to claim 1.

5. a sheet of paper on which an image is read by the first reading unit is transported along the same bypass path as a sheet of paper on which an image is read by the second reading unit; 2. The image reading device according to claim 1.

6. The first reading unit has a first scanner that reads an image formed on a back surface of a sheet of paper, and a second scanner that reads an image formed on a front surface of the sheet of paper.

2. The image reading device according to claim 1.

7. the second scanner is disposed downstream of the first scanner in the paper transport direction; 7. The image reading device according to claim 6.

8. the second reading unit is a colorimeter for measuring the color of an image; 2. The image reading device according to claim 1.

9. A paper transport path along which paper on which an image is formed is transported; a bypass path that branches off from the paper transport path and joins the paper transport path downstream of the branch point in the paper transport direction of the paper transport path, and through which paper is transported in one direction from the branch point to the joining point; a first reading unit that is disposed on the upstream side of the branch point in the paper transport direction with respect to the paper transport path and that reads an image formed on the paper; a second reading unit that is disposed with respect to the bypass path and reads an image formed on a sheet of paper; the second reading unit is a colorimeter for measuring the color of an image, adjusting sensitivity of the optical sensor used in the first reading unit based on colorimetric information obtained by measuring the colorimetric image formed on the paper transported to the bypass path by the colorimeter; Image reading device.

10. a conveying speed of the paper conveyed through the detour path when measuring the color of the image with the colorimeter is slower than a conveying speed of the paper conveyed through the paper conveying path; 9. The image reading device according to claim 8.

11. A paper transport path along which paper on which an image is formed is transported; a bypass path that branches off from the paper transport path and joins the paper transport path downstream of the branching point in the paper transport direction on the paper transport path, and through which paper is transported in one direction from the branching point to the joining point; a first reading unit that is disposed on the upstream side of the branch point in the paper transport direction with respect to the paper transport path and that reads an image formed on the paper; a second reading unit that is disposed with respect to the bypass path and reads an image formed on a sheet of paper; a path length from the first reading unit to the second reading unit is formed to be longer than a length in a conveying direction of a sheet of paper on which an image is read by the second reading unit; Image reader

12. an image forming unit that forms an image on a sheet; a paper transport path along which a paper sheet having an image formed thereon by the image forming unit is transported; a bypass path that branches off from the paper transport path and joins the paper transport path downstream of the branching point in the paper transport direction on the paper transport path, and through which paper is transported in one direction from the branching point to the joining point; a first reading unit that is disposed on the upstream side of the branch point in the paper transport direction with respect to the paper transport path and that reads an image formed on the paper; a second reading unit that is disposed with respect to the bypass path and reads an image formed on a sheet of paper; the bypass path has a straight horizontal portion, and the second reading unit is disposed on the horizontal portion; Image forming system.

13. a position of an image formed by the image forming unit is adjusted based on the read image information acquired by reading the first reading unit; The imaging system of claim 12.

14. An image forming unit that forms an image on a sheet of paper; a paper transport path along which a paper sheet having an image formed thereon by the image forming unit is transported; a bypass path that branches off from the paper transport path and joins the paper transport path downstream of the branching point in the paper transport direction on the paper transport path, and through which paper is transported in one direction from the branching point to the joining point; a first reading unit that is disposed on the upstream side of the branch point in the paper transport direction with respect to the paper transport path and that reads an image formed on the paper; a second reading unit that is disposed with respect to the bypass path and reads an image formed on a sheet of paper; a size of the image formed by the image forming unit is adjusted based on the read image information acquired by reading the first reading unit; Image forming system.

15. A judgment is made as to whether the image formed on the paper is good or bad based on the read image information acquired by reading the first reading unit. The imaging system of claim 12.

16. the paper sheet having passed through the first reading unit is sent to the bypass path, and a determination is made as to whether the image on the paper sheet is good or bad while the paper sheet is passing through the bypass path. The imaging system of claim 15.

17. A sheet on which an image determined to be defective is formed is discharged to a purge tray different from an output unit for a sheet on which an image determined to be good is formed. The imaging system of claim 15.

18. the second reading unit is a colorimeter for measuring the color of an image; The imaging system of claim 12.

19. performing color correction on the image formed by the image forming unit based on color measurement information obtained by measuring the color measurement image formed on the paper transported to the bypass path by the colorimeter; 20. The imaging system of claim 18.

Images