Image reading apparatus, image forming apparatus, image reading method, and program

Abstract

The present invention addresses the problem of reading color patches with excellent accuracy without using end marks. An image reading device (30) is provided with: conveyance paths (37, 38) for conveying a recording medium (S); a color measurement unit (34) that reads a color measurement target image (P) recorded on the recording medium (S) conveyed on the conveyance paths (37, 38); a detection unit (33) that detects the position of the recording medium (S) in a direction intersecting the transport direction of the recording medium (S); and a color measurement control unit (31) that controls the color measurement unit (34) so as to read the color measurement target image (P) on the basis of the detection result by the detection unit (33).

Description

Technical Field

[0001] The present invention relates to an image reading device, an image forming device, an image reading method, and a program. Background Art

[0002] The image forming device reads a color measurement chart to create a color profile. The color measurement chart is composed of an image in which a plurality of color patches for color measurement are arranged in a scanning direction orthogonal to the paper conveying direction. The image forming device forms the above-mentioned color measurement chart on a paper and reads the paper.

[0003] Furthermore, conventional image forming apparatuses form predetermined end marks at both ends of a patch sequence, and use the marks to detect the start position of reading the patch sequence (for example, Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-24006 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In conventional image forming apparatuses, an end mark for detecting the start position of color measurement is indispensable. Therefore, it is necessary to ensure an area on the recording medium for forming the end mark, which reduces the image area available to the user. In addition, since the end marks are formed at both ends of each color block column, the consumption of ink and toner increases.

[0009] An object of the present invention is to read color patches with high accuracy without using edge marks.

[0010] [Means for solving the problem]

[0011] In order to solve the above problems, the image reading device of the present invention comprises:

[0012] a conveying path for conveying a recording medium;

[0013] a colorimetric unit that reads a colorimetric target image recorded on the recording medium conveyed on the conveying path;

[0014] a detection unit that detects a position of the recording medium in a direction intersecting with a conveying direction of the recording medium; and

[0015] The colorimetric control unit controls the colorimetric unit to read the colorimetric target image based on the detection result by the detection unit.

[0016] Furthermore, in order to solve the above-mentioned problems, the image forming apparatus of the present invention comprises:

[0017] An image forming unit that records an image on a recording medium;

[0018] a conveying path for conveying the recording medium;

[0019] a colorimetric section that reads a colorimetric target image recorded by the image forming section on the recording medium conveyed on the conveying path;

[0020] a detection unit that detects a position of the recording medium in a direction intersecting with a conveying direction of the recording medium; and

[0021] The colorimetric control unit controls the colorimetric unit to read the colorimetric target image based on the detection result by the detection unit.

[0022] Furthermore, in order to solve the above-mentioned problems, an image reading method of an image reading device of the present invention is an image reading method of an image reading device comprising a conveying path for conveying a recording medium, a colorimetric unit for reading a colorimetric object image recorded on the recording medium conveyed on the conveying path, and a detection unit for detecting a position of the recording medium in a direction intersecting with a conveying direction of the recording medium.

[0023] The colorimetric section reads the colorimetric target image based on the detection result by the detection section.

[0024] In addition, in order to solve the above-mentioned problems, the program of the present invention enables a computer of an image reading device having a conveying path for conveying a recording medium, a colorimetric unit for reading a colorimetric object image recorded on the recording medium conveyed on the conveying path, and a detection unit for detecting the position of the recording medium in a direction intersecting with the conveying direction of the recording medium to realize a function in which the colorimetric unit reads the colorimetric object image based on a detection result based on the detection unit.

[0025] [Effects of the invention]

[0026] According to the present invention, it is possible to read color patches with high accuracy without using edge marks. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a front view showing a schematic configuration of the image forming apparatus according to the first embodiment.

[0028] Figure 2 This is a functional block diagram showing a control structure of the image forming apparatus according to the first embodiment.

[0029] Figure 3 This is a schematic diagram showing the structure of an image reading device arranged in the second transport path.

[0030] Figure 4 This is a conceptual diagram showing the slope correction operation of the paper by the correction unit.

[0031] Figure 5 This is a diagram showing an example of a graph image.

[0032] Figure 6 : is a flowchart showing the contents of the reading process of the chart image.

[0033] Figure 7 : is a flowchart showing the contents of image formation control.

[0034] Figure 8 It is a schematic diagram showing a partial configuration of an image reading device according to a second embodiment.

[0035] Fig. 9 is shown with Figure 8 A schematic diagram of a part of the structure of an image reading device in which a sheet of paper is conveyed forward compared to a state in which a sheet of paper is conveyed forward.

[0036] Fig.10 : is a flowchart showing the contents of the reading process of the chart image.

[0037] Fig.11 This is a front view showing a schematic structure of an image reading device in which the arrangement of the reading section is changed.

[0038] Description of Reference Numerals

[0039] 1: image forming device, 10: paper feeding device, 20: main body, 24: image forming unit, 26: control unit, 27: storage unit, 29: image processing unit, 30: image reading device, 31: control unit (colorimetry control unit), 32: reading unit, 33: detection unit, 34: colorimetry unit, 35: correction unit, 36: conveying unit, 37: first conveying path, 38: second conveying path, 351: loop roller (LoopRoller), 352: register roller (Register Roller), O: chart image, P, P1: color block (colorimetry object image), S: paper, sl: side end portion. DETAILED DESCRIPTION

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0041] [First embodiment]

[0042] like Figure 1 as well as Figure 2 As shown, the image forming apparatus 1 according to the first embodiment includes a paper feeding device 10 , a main body 20 , and an image reading device 30 .

[0043] The image forming apparatus 1 has a sheet S (see FIG. Figure 3 ) is disposed in sequence on the downstream side of the conveying direction of the paper feed device 10, the main body 20, and the image reading device 30. The conveying paths of the paper of the paper feed device 10, the main body 20, and the image reading device 30 are connected. Therefore, the paper S is continuously conveyed from the paper feed device 10 to the image reading device 30 via the main body 20.

[0044] [Paper feeding device]

[0045] The paper feeding device 10 includes a control unit 11 , a conveying unit 12 , a paper feeding unit 13 , and the like.

[0046] The control unit 11 includes a CPU, a ROM, and a RAM. CPU is the abbreviation of a central processing unit. ROM is the abbreviation of a read-only memory. RAM is the abbreviation of a random access memory.

[0047] The CPU of the control unit 11 reads out the program stored in the ROM and loads it into the RAM. The CPU controls the various parts of the paper feeding device 10 in a centralized manner according to the loaded program.

[0048] For example, the control unit 11 conveys the paper S from any of the paper feed trays 131 to 133 of the paper feed unit 13 to the main unit 20 according to a job.

[0049] The transport unit 12 includes a transport path 121 that connects the paper feed unit 13 to the main body 20 and transport rollers (not shown) that transport the paper S.

[0050] The paper feeding unit 13 includes paper feeding trays 131 to 133 for storing paper S of predetermined paper types and sizes.

[0051] A detection device for detecting the physical properties of the paper S may be provided between the paper feeding device 10 and the main body 20 .

[0052] [Main body]

[0053] The main body 20 is located on the downstream side of the paper feeding device 10 in the paper conveying direction and on the upstream side of the image reading device 30 in the paper conveying direction.

[0054] The main body 20 acquires image data obtained by reading an image from a manuscript and image data received from an external device (not shown). Based on the image data, the main body 20 forms a color image by an electrophotographic method. Furthermore, the main body 20 conveys the paper S on which the image has been formed to the image reading device 30.

[0055] like Figure 1 as well as Figure 2 As shown in FIG. 1 , the main body 20 has the following configuration: The main body 20 includes an operation unit 21 , a display unit 22 , a document reading unit 23 , an image forming unit 24 , a control unit 26 , a storage unit 27 , a communication unit 28 , and an image processing unit 29 .

[0056] The operation unit 21 includes various operation buttons such as a touch panel formed so as to cover the display screen of the display unit 22 , numeric buttons, and a start button.

[0057] The operation unit 21 outputs an operation signal based on the user's operation to the control unit 26 .

[0058] The display unit 22 includes an LCD (Liquid Crystal Display) and the like.

[0059] The display unit 22 displays various screens in accordance with instructions of display signals input from the control unit 26 .

[0060] The document reading unit 23 includes an automatic document feeding device (ADF: Automatic Document Feeder), a scanner, and the like.

[0061] The document reading unit 23 outputs image data obtained by reading an image of a document to the control unit 26 .

[0062] The image forming unit 24 forms an image on the paper S fed from the paper feeding device 10 by an intermediate transfer method based on the image data. In the present embodiment, the paper S is a single sheet of paper.

[0063] The image forming unit 24 includes a photosensitive drum, an intermediate transfer belt 242, a secondary transfer roller 243, a fixing unit 244, a reversing path 245, an alignment unit 246, and the like. The photosensitive drum includes a photosensitive drum corresponding to each color individually, namely, yellow (Y), magenta (M), cyan (C), black (K), and a special color (S). In the present embodiment, the special color is exemplified by white. That is, the photosensitive drum has a structure including photosensitive drums 241Y, 241M, 241C, 241K, and 241S.

[0064] After uniformly charging the photosensitive drum 241Y, the image forming unit 24 scans and exposes the photosensitive drum 241Y with a laser beam based on the yellow image data to form an electrostatic latent image. Next, the image forming unit 24 causes yellow toner to adhere to the electrostatic latent image on the photosensitive drum 241Y to develop the image.

[0065] The photosensitive drums 241M, 241C, 241K, and 241S are the same as the photosensitive drum 241Y except that they handle different colors, and thus their description is omitted.

[0066] The image forming unit 24 transfers the toner images of the respective colors formed on the photosensitive drums 241Y, 241M, 241C, 241K, and 241S to the intermediate transfer belt 242. The transfer to the intermediate transfer belt 242 is a primary transfer. That is, the image forming unit 24 forms a color toner image on the intermediate transfer belt 242 in which the toner images of the five colors are superimposed.

[0067] The image forming section 24 transfers the color toner image on the intermediate transfer belt 242 to the paper S at once by means of the secondary transfer roller 243. The transfer to the paper S is the secondary transfer. The nip portion formed by the intermediate transfer belt 242 and the secondary transfer roller 243 is the transfer portion.

[0068] The fixing unit 244 includes a heating roller for heating the sheet S to which the color toner image is transferred and a pressure roller for pressing the sheet S.

[0069] The fixing unit 244 fixes the color toner image to the paper S by applying heat and pressure.

[0070] In the case of single-sided printing in which an image is formed on one side of the paper S in the main body 20 , the control unit 26 conveys the paper S from the fixing unit 244 to the image reading device 30 .

[0071] On the other hand, in the case of double-sided printing in which images are formed on both sides of the paper S, the control unit 26 conveys the paper S from the fixing unit 244 to the reversing path 245 to reverse the paper surface. Then, the control unit 26 feeds the paper S again upstream of the registration unit 246 in the paper conveying direction.

[0072] The registration section 246 includes registration rollers and conveys the paper S to the transfer section.

[0073] The registration section 246 corrects the inclination of the sheet S fed from the sheet feeding device 10 and adjusts the feeding timing of the sheet S.

[0074] The control unit 26 includes a CPU, a RAM, a ROM, and the like.

[0075] The CPU of the control unit 26 reads out various processing programs stored in the ROM and loads them into the RAM. The control unit 26 controls the operation of the main body unit 20 in a unified manner in cooperation with the various programs loaded into the RAM.

[0076] The storage unit 27 is a nonvolatile storage device such as a HDD or a semiconductor memory that stores various data such as programs and image data. HDD is an abbreviation of a hard disk drive.

[0077] The storage unit 27 stores data such as program data and various setting data in a manner that can be read and written from the control unit 26 .

[0078] Furthermore, the storage unit 27 stores the paper feed trays 131 to 133 in association with information such as the basis weight, size, and paper type of the paper S stored therein.

[0079] The communication unit 28 includes, for example, a communication control card such as a LAN card.

[0080] The communication unit 28 transmits and receives various data to and from an external device (eg, a personal computer) connected to a communication network such as a LAN or WAN. LAN is the abbreviation for Local Area Network, and WAN is the abbreviation for Wide Area Network.

[0081] The image processing section 29 performs image processing required for image data before image formation. The image data includes data stored in the storage section 27, data obtained by reading a document by the document reading unit 23, and data input from an external device.

[0082] Next, the image processing unit 29 transmits the image data after the image processing to the image forming unit 24 .

[0083] The image processing includes grayscale processing, halftone processing, color conversion processing, etc. Grayscale processing is a process of converting the grayscale value of each pixel of the image data into a grayscale value that has been corrected so that the density characteristics of the image formed on the paper S match the target density characteristics. Halftone processing is error diffusion processing, screen processing using an ordered dithering method, etc. Color conversion processing is a process of converting each grayscale value of RGB into each grayscale value of CMYK.

[0084] The image processing unit 29 described above may be a functional structure realized by a program executed by the CPU of the control unit 26 .

[0085] [Image reading device]

[0086] The image reading device 30 is disposed on the downstream side of the main body 20 in the paper conveying direction.

[0087] The image reading device 30 reads the sheet S conveyed from the main body 20 , and outputs the obtained read image data to the control unit 31 .

[0088] The image reading device 30 includes a control unit 31 , a reading unit 32 , a conveying unit 36 ​​, a detecting unit 33 , and a color measuring unit 34 . The image reading device 30 further includes a correction unit 35 and a paper discharge tray 39 .

[0089] The transport unit 36 ​​includes a transport path that connects the main body 20 to the paper discharge tray 39 and transport rollers (not shown) that transport the paper S.

[0090] The transport path includes a first transport path 37 that connects the main body 20 to the paper discharge tray 39 in a substantially straight line. The transport path also includes a second transport path 38 that branches from the first transport path 37 and then merges with the first transport path 37 again after making a detour downward.

[0091] The second conveying path 38 branches off from the first conveying path 37 , makes a large detour downward, and then makes its forward route upward to merge with the first conveying path 37 .

[0092] The paper S that is transported by detouring the second transport path 38 has a longer transport distance than the paper S that is transported only along the first transport path 37 .

[0093] The first conveying path 37 and the second conveying path 38 are both constituted by guides and walls for guiding the paper S along the conveying paths. Alternatively, the first conveying path 37 and the second conveying path 38 may be constituted by a plurality of guide rollers arranged along the respective paths.

[0094] A branch guide (not shown) capable of changing the path of the paper S is disposed at the branch position from the first conveying path 37 to the second conveying path 38. The branch guide can change its direction by an actuator controlled by the control unit 31. By changing the direction of the dividing member, the paper S can be switched between conveyance in which the paper S maintains the advance of the first conveying path 37 and conveyance in which the paper S enters the second conveying path 38.

[0095] The reading unit 32 is disposed at a position upstream of the branching position of the first conveying path 37 with the second conveying path 38 in the paper conveying direction.

[0096] The reading unit 32 reads the image formed on the paper S by the image forming unit 24, obtains the read image data, and outputs it to the image processing unit 29. The reading unit 32 is composed of, for example, a color scanner, etc. The reading unit 32 is arranged on the downstream side of the image forming unit 24 in the paper conveying direction, so that the image can be read during the paper conveying.

[0097] The reading unit 32 has independent detection elements on both sides of the paper S conveyed in the first conveying path 37. One detection element reads an image on one side, for example, the upper side, of the paper S. The other detection element reads an image on the other side, for example, the lower side of the paper S.

[0098] The image read by the reading unit 32 is analyzed by the image processing unit 29. The image processing unit 29 not only performs image processing on the image data before image formation, but also analyzes the image read by the reading unit 32. In this case, the image processing unit 29 calculates the positional deviation of the image formed on the front and back of the paper S with respect to the paper S, the adjustment value of the positional deviation, the adjustment value of the color of the image, etc. In addition, the image processing unit 29 detects defects in the formed image. The image processing unit 29 outputs the analysis result to the control unit 26 of the main body 20.

[0099] Furthermore, the control unit 31 performs various calibrations based on the read image read by the reading unit 32 .

[0100] Figure 3 1 is a schematic diagram showing the structure of the image reading device 30 arranged on the second transport path 38 . Figure 3 The X-axis direction shown indicates the paper conveying direction, and the Y-axis direction indicates the direction orthogonal to the paper conveying direction.

[0101] In addition, the so-called "direction perpendicular to the paper conveying direction" means a direction parallel to the plane of the paper being conveyed and perpendicular to the paper conveying direction. Hereinafter, the "direction perpendicular to the paper conveying direction" is referred to as the "conveying perpendicular direction".

[0102] also, Figure 3 The lower side in the figure indicates the upstream side in the paper conveying direction. Figure 3 The upper side in represents the downstream side in the paper conveying direction.

[0103] The correction unit 35 , the detection unit 33 , and the color measurement unit 34 are arranged in this order on the downstream side of the second conveyance path 38 in the paper conveyance direction.

[0104] The correction unit 35 corrects the inclination of the paper S conveyed along the second conveyance path 38. It is an ideal state for the rectangular paper S to be conveyed with its side end s1 parallel to the paper conveyance direction.

[0105] The side end of the paper S refers to the end along the short side or the long side of the rectangular paper S. In the following description, the paper S is transported so that the end along the long side is parallel to the transport direction.

[0106] The correction unit 35 corrects the orientation of the paper S so that the side end s1 of the paper S becomes close to being parallel to the conveyance direction.

[0107] The correction unit 35 includes a circulation roller 351 and a registration roller 352. The circulation roller 351 and the registration roller 352 each include a roller pair that rotates around an axis in a direction perpendicular to the paper conveying direction. The two rollers constituting the roller pair rotate in opposite directions to each other, and the paper S can be conveyed in the conveying direction through the clamping portion of the roller pair.

[0108] The circulation roller 351 is arranged upstream of the registration roller 352 in the conveying direction. The interval between the circulation roller 351 and the registration roller 352 in the paper conveying direction is shorter than a given distance. The given distance in this case indicates the length of the smallest paper S to be conveyed in the conveying direction.

[0109] A space is ensured between the circulation roller 351 and the registration roller 352 to allow a loop (slack) to be generated in the paper S. This space is formed on both sides of the second conveying path 38 in a direction perpendicular to the plane of the conveyed paper S.

[0110] The circulation roller 351 and the registration roller 352 each include a motor as a driving source. The control unit 31 can independently control the driving and stopping of each motor. That is, the correction unit 35 corrects the slope of the paper S in cooperation with the control unit 31.

[0111] Figure 4 1 is a conceptual diagram showing the slope correction operation of the paper S by the correction unit 35 .

[0112] When the correction operation by the correction unit 35 starts, the driving of the motor of the registration roller 352 is stopped. At this time, the motor is controlled so as to stop the rotation of each roller of the registration roller 352.

[0113] On the other hand, the circulation roller 351 conveys the sheet S toward the registration roller 352 side.

[0114] As a result, the leading end portion of the sheet S on the downstream side in the sheet conveyance direction is pressed by the nip portion of the registration roller 352. The nip portion of the registration roller 352 is parallel to the conveyance orthogonal direction.

[0115] like Figure 4 As shown by the solid line, there is a case where the paper S is tilted relative to the paper conveying direction. In this case, as shown by the double-dashed line, the front end of the paper S is corrected in the direction perpendicular to the conveying direction by abutting to imitate the clamping part of the registration roller 352. In addition, there is a case where the side end of the paper S is loose and a loop is generated.

[0116] In this state, by driving and rotating the resist roller 352 in the paper conveyance direction, the paper S can be conveyed with the side end portions thereof along the paper conveyance direction.

[0117] The detection unit 33 detects the position of the paper S in the conveyance orthogonal direction. More specifically, the detection unit 33 can detect the position of the side end s1 on one side of the paper S in the conveyance orthogonal direction.

[0118] The detection unit 33 is composed of, for example, a line sensor. Figure 3 As shown, the detection section 33 is arranged so that the linear detection range is parallel to the conveyance orthogonal direction and faces the conveyed paper S side.

[0119] The detection unit 33 may include a light source for irradiating the paper S. The detection unit 33 can detect the position of the side end s1 of the paper S in the direction perpendicular to the conveyance by using the difference in brightness of the reflected light.

[0120] The detection range of the detection unit 33 is configured to include a position where at least one side end s1 of the sheet S conveyed in the second conveying path 38 in the conveying orthogonal direction passes. In addition, there is a case where the sheet S may be positionally shifted in any direction in the conveying orthogonal direction in the second conveying path 38. It is preferable that the detection unit 33 be set to a detection range that can adequately cope with the positional shift that may occur in the conveying orthogonal direction of the sheet S.

[0121] The color measuring unit 34 reads the chart image O recorded on the paper S transported along the second transport path 38 .

[0122] Here, a description will be given of a chart image O recorded on a sheet S. The chart image O is a calibration chart composed of a plurality of color patches P, which are colorimetric target images having combinations of predetermined grayscale values. Figure 5 2 is a diagram showing an example of a graph image O.

[0123] About Figure 5 The description is made on the premise that the paper S on which the chart image O is formed is arranged in the conveyance path in an appropriate orientation.

[0124] The chart image O is an image composed of a plurality of color blocks P arranged in a row along a direction perpendicular to the conveyance direction, wherein a plurality of color blocks are arranged in parallel in the paper conveyance direction. Figure 5 In the example of FIG. 1 , the color block P is a square, but it may be a rectangle or other shape. The shape and size of each color block P are equal. In addition, each color block P or each color block column may be formed without gaps or with gaps.

[0125] It is preferable that all combinations of grayscale values ​​representing the color tone of the color patch P are different for each color patch P.

[0126] The chart image O is formed on one side of the paper S by the image forming section 24 of the main body section 20 . The color measuring section 34 reads each color patch P of the chart image O formed by the image forming section 24 .

[0127] The colorimetric unit 34 is composed of a spectrophotometer and can perform colorimetric measurement with higher accuracy than the reading unit 32 composed of a color scanner.

[0128] The color measurement unit 34 measures all the color patches P of the chart image O individually, and outputs the results to the control unit 31. The control unit 31 compares the grayscale value of each color patch P specified in the image data of the chart image O with the grayscale value measured by the color measurement unit 34. Then, the control unit 31 creates a so-called color profile through these comparisons.

[0129] The color profile is transmitted to the main body unit 20. The color profile is referred to by the control unit 26 when the image forming unit 24 forms an image, and is reflected in the correction of the color tone.

[0130] As described above, the color measuring unit 34 individually measures a plurality of color patches P regularly arranged in the conveying direction orthogonal to the conveying. To this end, the color measuring unit 34 is supported by a carriage-type conveying mechanism (not shown). The conveying mechanism can convey the color measuring unit 34 in the conveying direction orthogonal to the conveying and position it arbitrarily under the control of the control unit 31.

[0131] Figure 5 The color patch P1 of the illustrated chart image O indicates a color patch that is the measurement start position by the color measuring unit 34. That is, the color patch P1 is a color patch belonging to the color patch column on the most downstream side in the paper conveying direction. Furthermore, the color patch P1 is a color patch located at one end (for example, the detection unit 33 side) in the conveying orthogonal direction in the color patch column. Thus, the measurement start position of the chart image O is preferably set to the position of the color patch P located at the corner of the downstream end in the paper conveying direction.

[0132] The positions of all color patches on the sheet S in the direction perpendicular to the conveyance direction can be acquired from the image data of the chart image O, so the positions of all color patches can be said to be known. In addition, the "position of the color patch" mentioned here includes the position of the corner of the color patch and the center position of the color patch.

[0133] Figure 3 The single-point dashed line in FIG. 1 is a straight line passing through the position of the color patch P1 along the paper conveying direction. As described above, the position of the color patch P1 in the plane of the paper S can be obtained. Therefore, the distance Dy in the conveying orthogonal direction from the side end s1 of the paper S to the position of the color patch P1 can also be obtained.

[0134] The position of the side end s1 of the paper S in the direction perpendicular to the conveyance can be detected by the detection unit 33. Thus, the control unit 31 can acquire the position of the patch P1 in the direction perpendicular to the conveyance, that is, the measurement start position in the direction perpendicular to the conveyance.

[0135] For example, the detection unit 33 detects the distance Ds in the conveyance orthogonal direction from a preset reference position B in the conveyance orthogonal direction to the side end s1 of the paper S. The reference position B is a target position through which the side end s1 of the properly conveyed paper S should pass.

[0136] In this case, the control unit 31 calculates the position of the patch P1 in the direction perpendicular to the conveyance by using Ds+Dy.

[0137] Thus, the control unit 31 controls the transport mechanism of the color measuring unit 34 so that the reading start position becomes Ds+Dy when the reading of the chart image O starts.

[0138] In addition, when reading the chart image O, it is also necessary to perform relative positioning of the paper S and the color measuring unit 34 in the paper conveyance direction.

[0139] The positioning in the paper conveying direction is performed by controlling the rotation amount of the above-mentioned registration roller 352.

[0140] The distance F from the registration roller 352 to the color measuring unit 34 in the paper conveying direction can be acquired from the design value. In addition, the position of the color patch P1 in the paper conveying direction on the paper S can also be acquired from the image data of the chart image O. Therefore, the distance Dx in the paper conveying direction from the end of the downstream side of the paper S in the paper conveying direction to the position of the color patch P1 can also be acquired.

[0141] Therefore, the control unit 31 controls the motor so as to convey the motor by the distance F+Dx from the start of driving the registration roller 352 at the time of the slope correction by the correction unit 35 described above.

[0142] Thus, the control unit 31 can perform positioning in the paper conveyance direction so that the color measuring unit 34 is at the reading start position.

[0143] Furthermore, in order to detect the conveyance amount of the sheet S in the sheet conveyance direction with higher accuracy, a sensor such as an encoder that detects the rotation speed of the registration roller 352 may be provided.

[0144] [Reading of Chart Image by Image Reading Device]

[0145] The image forming apparatus 1 can selectively execute a colorimetric mode and a non-colorimetric mode. In the colorimetric mode, the image forming apparatus 1 performs formation to reading of a chart image O. In the non-colorimetric mode, the image forming apparatus 1 performs image formation based on arbitrary image data.

[0146] These mode selections are performed by an operator's input from the operation unit 21 of the main body 20 .

[0147] When the colorimetric mode is selected, the control unit 26 of the main body 20 reads the image data of the chart image O prepared in the storage unit 27 . Furthermore, the control unit 26 sends a notification of the execution of the colorimetric mode to the control unit 31 of the image reading device 30 .

[0148] Then, the control unit 26 requests the paper feeding device 10 to convey a predetermined paper S for forming the chart image O.

[0149] Then, the control unit 26 controls the image forming unit 24 to form a chart image O based on the image data on the sheet S fed from the sheet feeding device 10 .

[0150] Then, the control unit 26 conveys the paper S on which the chart image O is formed to the image reading device 30 .

[0151] Next, a chart image reading process performed by the control unit 31 of the image reading device 30 will be described.

[0152] The chart image reading process is executed by the CPU of the control unit 31 reading a program prepared in the storage unit 27 of the main body unit 20 .

[0153] Figure 6 2 is a flowchart showing the contents of the reading process of the chart image. Figure 3 to Figure 6 The content of the chart image reading process will be described.

[0154] The control unit 31 receives a command for executing the color measurement mode from the main body unit 20, and controls the branch guide of the conveying unit 36. This puts the paper S in a state where it can be conveyed to the second conveying path 38 (S1).

[0155] Next, the control unit 31 controls the conveying unit 36 ​​to start conveying the paper S ( S3 ).

[0156] In this case, the conveyance speed of the paper S may be set lower than that in the non-colorimetric mode, or may be set equal to that in the non-colorimetric mode.

[0157] Then, when the paper S on which the chart image O is formed is supplied from the main body 20 , the paper S is guided to the second transport path 38 .

[0158] The correction unit 35 performs slope correction (S5) when the paper S arrives. In addition, a sensor for detecting the arrival of the paper S may be provided in the correction unit 35. The sensor may also detect the downstream end of the paper S in the paper conveying direction. The sensor may also be arranged around the clamping portion of the circulation roller 351 or the registration roller 352 or in front of it.

[0159] like Figure 4As shown, the control unit 31 drives the circulation roller 351 with respect to the registration roller 352 in the stopped state. Thus, the slope correction is performed so that the downstream end of the sheet S in the sheet conveyance direction becomes substantially parallel to the conveyance orthogonal direction.

[0160] Then, the control unit 31 drives the registration roller 352 and the circulation roller 351 to restart the conveyance (S7).

[0161] In this case, the conveyance speed of the paper S is lower than that in the non-colorimetric mode. Thus, the control unit 31 functions as a "conveying control unit."

[0162] The detection unit 33 detects the position of the side end s1 of the transported sheet S in the direction perpendicular to the transport ( S9 ).

[0163] The control unit 31 calculates the position of the color patch P1 in the conveyance direction of the chart image O based on the detected position of the side end s1 in the conveyance direction. Then, the control unit 31 controls the conveying mechanism to position the color measuring unit 34 using the position of the color patch P1 in the conveyance direction as the reading start position (S11).

[0164] The control unit 31 functions as a “colorimetry control unit” by performing the above-described positioning control of the colorimetry unit 34 .

[0165] The control unit 31 controls the motors of the registration roller 352 and the circulation roller 351 to position the color patch P1 of the paper S in the paper conveying direction (S13). In this case, the positioning is performed so that the position of the color patch P1 of the paper S in the paper conveying direction coincides with the reading position of the color measuring unit 34. By this positioning, the driving of the motors of the registration roller 352 and the circulation roller 351 is temporarily stopped.

[0166] In addition, the control unit 31 may execute the processes of S11 and S13 in reverse order. In addition, the control unit 31 may execute the processes of S11 and S13 in parallel.

[0167] Through the processing of S11 and S13 , the position of the color patch P1 on the paper S and the reading position of the color measuring unit 34 are substantially aligned in a plan view.

[0168] From this state, the control unit 31 sequentially executes reading of each color patch P by the color measuring unit 34 ( S15 ).

[0169] First, control unit 31 causes color measuring unit 34 to measure the color of each patch P while conveying the patch row in the orthogonal conveyance direction to the end of the patch row opposite to patch P1. Hereinafter, the reading operation of one patch row by color measuring unit 34 is referred to as scanning.

[0170] Furthermore, the control unit 31 controls the motors of the registration roller 352 and the circulation roller 351 to convey the paper S at the aforementioned low speed.

[0171] Thereafter, the control unit 31 executes scanning by the color measuring unit 34 for each color patch row.

[0172] Alternatively, the color measuring unit 34 may scan each patch row by returning the color measuring unit 34 to the reading start position in the direction perpendicular to the conveyance, and performing scanning by moving in the same direction each time.

[0173] Alternatively, the color measuring unit 34 may perform scanning by alternating between scanning by movement in one direction and scanning by movement in the other direction along the direction perpendicular to the conveyance.

[0174] When the control unit 31 has completed reading the chart image O, it compares the read data with the image data of the chart image O and creates a color profile for the image forming unit 24 ( S17 ). The color profile is sent to the control unit 26 of the main body unit 20 .

[0175] Then, the control unit 31 discharges the paper S to the paper discharge tray 39 by controlling the conveying unit 36 ​​( S19 ), and ends the reading process in the colorimetric mode.

[0176] Alternatively, the control unit 31 may send the read data of the chart image O to the control unit 26 of the main unit 20 without creating a color profile in S17. In this case, the control unit 26 of the main unit 20 that receives the read data creates a color profile.

[0177] [Image formation by main body]

[0178] The image formation control in the main body 20 after the color profile is acquired will be described. The image formation control is executed by the CPU of the control unit 26 reading a program prepared in the storage unit 27 .

[0179] In addition, this image forming process is based on the premise that the non-colorimetric mode is selected.

[0180] Therefore, the control unit 26 sends a notification of the non-colorimetric mode to the control unit 31 of the image reading device 30 . The control unit 31 of the image reading device 30 then controls the branch guide of the conveying unit 36 ​​to wait so that the paper S can be conveyed only in the first conveying path 37 .

[0181] Figure 7 FIG. 4 is a flowchart showing the contents of image formation control. Figure 7 The contents of image formation control will be described.

[0182] The control unit 26 acquires image data (S21). The image data may be acquired from the document reading unit 23 or may be image data received from an external device (not shown).

[0183] Then, the control unit 26 requests the paper feeding device 10 to convey the paper S ( S23 ).

[0184] The acquired image data is subjected to image processing such as grayscale processing, halftone processing, and color conversion processing by the image processing unit 29. Furthermore, the control unit 26 or the image processing unit 29 refers to the color profile acquired from the image reading device 30 to correct the grayscale value of the image data.

[0185] Then, the control unit 26 controls the image forming unit 24 to perform image formation on the transported paper S based on the corrected image data ( S25 ).

[0186] Then, the control unit 26 conveys the sheet S on which the image is formed to the image reading device 30 ( S23 ).

[0187] The reading unit 32 is disposed upstream in the paper conveying direction in the first conveying path 37 of the image reading device 30. Therefore, the control unit 26 can quickly acquire read image data of the paper S by the reading unit 32 through the control unit 31 as the paper S is conveyed to the image reading device 30.

[0188] The image processing unit 29 analyzes the image data read by the reading unit 32. The image processing unit 29 detects the positional deviation of the formed image with respect to the paper S and defects in the formed image.

[0189] The control unit 26 determines whether the formed image is good or bad based on the detection result of the image processing unit 29 ( S29 ).

[0190] Then, when the control unit 26 determines that the quality of the formed image is appropriate, the control unit 31 directly discharges the paper S to the paper discharge tray 39 (S31). Then, the control unit 26 ends the image formation control.

[0191] On the other hand, when the control unit 26 determines that the quality of the formed image is inappropriate, the control unit 26 causes the display unit 22 to display an image formation error to report it (S33).

[0192] Furthermore, the control unit 26 corrects the image data (S35) based on the adjustment value of the positional shift and the adjustment value of the image color obtained by the image analysis by the image processing unit 29. Thus, the control unit 26 and the image processing unit 29 cooperate to function as an "image control unit".

[0193] Then, the control unit 26 returns the process to S23 and performs image formation on the newly supplied paper S again.

[0194] [Technical Effects of the First Embodiment]

[0195] In image reading device 30 of image forming apparatus 1 , control unit 31 controls color measuring unit 34 to read color patch P based on the detection result by detection unit 33 .

[0196] Thus, even if the position of the paper S in the direction perpendicular to the conveyance is shifted in the second conveyance path 38 , the color measuring unit 34 can properly read the color patch P. Furthermore, even if the position of the paper S in the direction perpendicular to the conveyance is changed in the second conveyance path 38 , the color measuring unit 34 can properly read the color patch P.

[0197] Therefore, the image forming apparatus 1 can acquire a color profile with higher accuracy and can perform high-quality image formation.

[0198] Furthermore, it is not necessary to mark the ends of the color block array as in the past. Therefore, the image forming apparatus 1 no longer needs to ensure an area for forming the end mark on the paper S, thereby expanding the image area available to the user. In addition, since the end mark is not required, the image forming apparatus 1 can reduce the consumption of toner.

[0199] In addition, the control unit 31 controls the reading position by the color measuring unit 34 based on the detection result by the detection unit 33. Therefore, the color measuring unit 34 can read each color patch P at an appropriate position in the conveying orthogonal direction. Therefore, the image reading device 30 can obtain a high-precision reading result for the chart image O.

[0200] Furthermore, in the image reading device 30 of the image forming apparatus 1 , the color measuring unit 34 is movable in the direction perpendicular to the conveyance.

[0201] Therefore, the image reading device 30 does not require a large sensor that extends over the entire width of the paper S, and can use a small detection element or the like.

[0202] In particular, when color measuring unit 34 is movable, each patch P arranged along the patch row can be read well. Therefore, image reading device 30 can appropriately adapt the detection result by detection unit 33 to the control of the reading position.

[0203] Thus, the image reading device 30 can obtain a reading result of the chart image O with high accuracy.

[0204] In addition, a plurality of color patches P are recorded along the direction perpendicular to the conveyance in the chart image O of the paper S. Therefore, when the color measuring unit 34 is movable along the direction perpendicular to the conveyance, the color patches P can be read particularly well.

[0205] Thus, the image reading device 30 can obtain a reading result of the chart image O with high accuracy.

[0206] Furthermore, the control unit 31 controls the determination of the reading start position of the color measuring unit 34 based on the detection result of the detection unit 33. The arrangement direction of the color patches P of the color patch array constituting the chart image O and the moving direction of the color measuring unit 34 are both in the conveying orthogonal direction. Therefore, if the reading start position of the color measuring unit 34 is determined, the entire color patch array can be properly read. Therefore, the image reading device 30 can perform good reading for each color patch P under simple control.

[0207] Furthermore, before the color measuring section 34 starts reading the color patch P, the control section 31 adjusts the position of the color measuring section 34 in the direction perpendicular to the conveyance.

[0208] Thus, image reading device 30 can perform color measurement with high accuracy at the start of reading of color patches P.

[0209] In the image reading device 30 , the detection section 33 is disposed upstream of the color measuring section 34 in the paper conveyance direction.

[0210] Therefore, even when the color patch P is formed at any position of the paper S, the color measuring unit 34 can read the color patch P using the detection result of the detection unit 33. Therefore, the formation range of the color patch P with respect to the plane of the paper S can be expanded. Therefore, the color patch P can be formed in the chart image O at a high density.

[0211] The colorimetric control unit 31 can selectively implement the colorimetric mode and the non-colorimetric mode. Therefore, the image reading device 30 can avoid the situation when the colorimetric measurement based on the colorimetric unit 34 is not needed. In this case, the operation and detection frequency of the colorimetric unit 34 can be reduced, and the operation burden of the driving unit and the colorimetric unit 34 and the processing burden of the detection data can be reduced.

[0212] Furthermore, the image reading device 30 includes the correction unit 35 upstream in the conveyance direction from the color measuring unit 34. Therefore, the inclination of the paper S can be reduced, and the color measuring unit 34 can read each color patch P with higher accuracy.

[0213] Furthermore, the detection unit 33 is disposed on the downstream side of the paper conveyance direction relative to the correction unit 35. Therefore, the correction unit 35 can correct the slope of the paper S before the detection unit 33 detects it.

[0214] In addition, the detection unit 33 can detect the position of the paper S in a state where the inclination of the paper S is corrected, and thus can perform more appropriate detection. Therefore, the color measurement unit 34 can read each color patch P with higher accuracy.

[0215] Furthermore, the control unit 31 performs control to lower the conveyance speed of the paper S when passing through the color measuring unit 34 in the color measuring mode compared to the non-color measuring mode.

[0216] Thus, image reading device 30 can read color patches P with higher accuracy using color measuring section 34 .

[0217] In image reading device 30 , color measuring section 34 is configured to include a spectrophotometer, so that color patches P can be read with higher accuracy than with a color scanner or the like.

[0218] The image forming apparatus 1 also includes a reading unit 32 that reads an image recorded on the sheet S by the image forming unit 24. The image processing unit 29 corrects the image data based on the image reading result. The control unit 26 controls the image forming unit 24 to form an image based on the corrected image data.

[0219] Thus, the image forming apparatus 1 can form a high-quality image.

[0220] In the image forming apparatus 1, a color profile is created based on the reading result of the chart image O by the color measuring unit 34. Furthermore, when correcting the image data described above, the color profile is referred to and the image data is corrected based on the profile.

[0221] Therefore, the image forming apparatus 1 can form an image with even higher quality.

[0222] Furthermore, in the image forming apparatus 1 , in the image reading device 30 , the reading section 32 is arranged upstream of the correction section 35 and the detection section 33 in the paper conveyance direction.

[0223] Thereby, the reading result of the image by the reading unit 32 can be acquired at an earlier stage. The processing and control to be performed using the reading result of the image by the reading unit 32 can be performed at an earlier stage.

[0224] [Second Embodiment]

[0225] A second embodiment will be described with reference to the drawings.

[0226] The second embodiment shows an example in which the arrangement of the detection unit 33 and the correction unit 35 is changed in the image reading device 30 .

[0227] Figure 81 is a schematic diagram showing the structure of the image reading device 30 arranged on the second transport path 38 .

[0228] In the configuration of the first embodiment, the correction section 35 is disposed upstream of the detection section 33 in the paper conveying direction. More specifically, the downstream end portion (registration roller 352) of the correction section 35 in the paper conveying direction is disposed upstream of the detection section 33 in the paper conveying direction.

[0229] In contrast, in the structure of the second embodiment, the configuration of the correction unit 35 and the detection unit 33 is as follows: Figure 8 shown.

[0230] That is, the correction section 35 is disposed on the downstream side of the detection section 33 in the paper conveyance direction.

[0231] More specifically, the downstream end portion (register roller 352) of the correction section 35 in the paper conveying direction is arranged at a position downstream of the detection section 33 in the paper conveying direction. On the other hand, the upstream end portion (circulation roller 351) of the correction section 35 in the paper conveying direction is arranged at a position upstream of the detection section 33 in the paper conveying direction.

[0232] That is to say, Figure 8 as well as Fig. 9 In the case of the illustrated arrangement, the detection unit 33 is arranged between the registration roller 352 and the circulation roller 351 .

[0233] Therefore, the correction unit 35 and the detection unit 33 can be arranged collectively in the paper conveyance direction. As a result, the second conveyance path 38 where these are arranged can be reduced in size, and the image reading device 30 can be reduced in size.

[0234] However, in the above configuration, the detection section 33 is separated from the color measuring section 34 in the paper conveying direction. On the other hand, there is a case where the paper S is tilted again due to conveying skew after the slope correction by the correction section 35 .

[0235] In this case, there is a problem that the detection unit 33 and the color measurement unit 34 are separated and thus are easily significantly affected by the inclination of the paper S.

[0236] Fig. 9 The state is shown until the paper S is conveyed to the position of the patch P1 , that is, the reading start position, after the slope correction by the correction unit 35 . Fig.10 1 is a flowchart showing a reading process of the chart image O executed by the control unit 31 in order to solve the above-mentioned problem.

[0237] The reading process of the chart image O is executed by the CPU of the control unit 31 reading a program prepared in the storage unit 27 of the main body unit 20 .

[0238] In the case of this reading process, it is also premised that the colorimetric mode is selected.

[0239] The control unit 31 sets the paper S to a state where it can be transported to the second transport path 38 ( S41 ).

[0240] Next, the control unit 31 starts conveyance of the paper S on which the graphic image O is formed ( S43 ).

[0241] When the paper S arrives, the correction unit 35 performs slope correction ( S45 ).

[0242] Then, the first detection of the position of the side end s1 in the conveyance orthogonal direction by the detection unit 33 is performed on the sheet S immediately after the slope correction (S47: see Figure 8 ).

[0243] Thus, the control unit 31 acquires the position Ds1 of the side end s1 of the sheet S in the conveyance orthogonal direction.

[0244] Then, the control section 31 drives the registration rollers 352 and the circulation rollers 351 to resume conveyance at a low speed (S49).

[0245] The control unit 31 causes the color measuring unit 34 to position the color patch P1 of the paper S in the paper conveyance direction and stops conveyance (S51: see Fig. 9 The color patch P1 can be positioned at the color measuring section 34 by being transported a distance F+Dx in the paper transport direction from the position of the paper S immediately after the slope correction.

[0246] As described above, distance F is the distance from registration roller 352 to color measuring section 34 in the paper conveying direction. Distance Dx is the distance in the paper conveying direction from the downstream end of paper S in the paper conveying direction to the position of patch P1.

[0247] Then, for the sheet S on which the patch P1 has been positioned, a second detection of the position of the side end s1 in the conveyance-orthogonal direction by the detection unit 33 is performed (S53: see Fig. 9 ).

[0248] Thus, the control unit 31 acquires the position Ds2 of the side end s1 of the paper S in the conveyance orthogonal direction.

[0249] Next, the control unit 31 calculates the slope of the paper S based on the positions Ds1 and Ds2 of the side end s1 of the paper S in the conveyance orthogonal direction and the conveyance distance F+Dx of the paper S during this period ( S55 ).

[0250] That is, while the paper S moves by the distance F+Dx in the paper conveyance direction, it moves by the distance Ds2-Ds1 in the conveyance orthogonal direction.

[0251] Therefore, the control unit 31 calculates the slope using the following equation (1).

[0252] Slope = (Ds2 - Ds1) / (F + Dx) ... (1)

[0253] The control unit 31 may also multiply the slope of the above formula (1) by the conveyance distance in the paper conveyance direction from the time point when the slope correction of the paper S is performed. Thus, the control unit 31 can calculate the correction amount in the conveyance orthogonal direction of the paper S that changes according to the conveyance distance of the paper S in the paper conveyance direction from the time point when the slope correction of the paper S is performed.

[0254] In addition, depending on the paper type, sometimes the above correction cannot be completely corrected. In this case, a correction table for each paper type may be prepared in the storage unit, and correction may be performed with reference to the table. The paper type may be input in advance by the user, or a detection unit capable of detecting the paper type may be provided in the image reading device 30 or an upstream device, and the control unit 31 may perform correction corresponding to the paper type.

[0255] The control unit 31 corrects the position of the color patch P1 according to the slope of the paper S. Then, the color measuring unit 34 is positioned at the corrected position of the color patch P1 in the direction perpendicular to the conveyance (S57).

[0256] Next, the control unit 31 reads the chart image O by the colorimetric unit 34 ( S59 ).

[0257] After the position of patch P1 is corrected, the slope of paper S may change as it is transported in the paper transport direction. In this case, control unit 31 calculates the slope sequentially and reads by color measuring unit 34 while correcting the position of each patch P.

[0258] Next, when the control unit 31 has completed reading the chart image O, it compares the read data with the image data of the chart image O and creates a color profile for the image forming unit 24 ( S61 ). The control unit 31 sends the color profile to the control unit 26 of the main body unit 20 .

[0259] Then, the control unit 31 discharges the paper S ( S63 ) and ends the reading process.

[0260] In the above-mentioned image reading device 30, the control unit 31 performs detection by the detection unit 33 after the slope correction by the correction unit 35 and when the color patch P1 is read by the color measurement unit 34. Then, the control unit 31 obtains the slope of the paper S based on the two detection results and performs correction of the reading position by the color measurement unit 34.

[0261] Therefore, even if the paper S has a slope due to conveyance deviation or the like after the slope correction, the color measurement unit 34 can read each color patch P with high accuracy.

[0262] In particular, Figure 8 In this way, even in the case of a configuration in which the color measuring section 34 is easily affected by the slope of the paper S, the color measuring section 34 can perform reading with high accuracy.

[0263] In addition, the above-mentioned reading process accompanied by correction based on the slope of the paper S can also be applied to Figure 1 The image reading device 30 has a structure. Figure 1 In the case of the image reading device 30, the influence of the slope of the paper S is small. Figure 1 Even in the case of the image reading device 30 , the chart image O can be read with the influence of the slope of the paper S further reduced.

[0264] [other]

[0265] In addition, the image forming apparatus or the image reading apparatus is not limited to the above-mentioned configuration.

[0266] For example, Fig.11 Like the image reading device 30 of FIG. 3 , the reading unit 32 may be arranged at a position downstream of the color measuring unit 34 in the paper conveying direction. In this case, the reading unit 32 cannot read the image immediately after the image is formed. In addition, in the case of this arrangement, the correction unit 35 can correct the slope of the paper S before the reading unit 32 reads the image. Regarding aspects other than these, Fig.11 The image reading device 30 can obtain Figure 1 or Figure 8 The image reading device 30 has the same technical effect.

[0267] Furthermore, the detection unit 33 may be arranged at a position downstream of the color measuring unit 34 in the paper conveying direction. For example, each color patch P may be formed by being separated from the end portion on the downstream side in the paper conveying direction of the paper S. In such a case, based on the detection result of the detection unit 33, reading by the color measuring unit 34 can be performed with high accuracy.

[0268] In addition, the color measuring unit 34 is not limited to a structure supported so as to be movable in the direction perpendicular to the conveyance.

[0269] For example, the image reading device may also use a colorimetric unit that can read the entire width of a long strip in the conveying direction orthogonal to the conveyed paper S. In this case, it is no longer necessary to position the colorimetric unit 34 for conveying. For example, the colorimetric unit reads the chart image while determining which color patch P corresponds to the detection result at each position in the conveying direction orthogonal to the detection surface of the long strip.

[0270] In addition, the correction unit 35 is not limited to Figure 4 Alternatively, other structures capable of correcting the slope of the paper S may be selected. For example, the correction unit may be configured to include two rollers arranged in a direction perpendicular to the conveying direction and a motor capable of controlling the speed of each roller. In this case, the paper S is conveyed by each roller with a speed difference set on one side and the other side in the direction perpendicular to the conveying direction, thereby correcting the slope of the paper S.

[0271] In addition, in the case of the above structure, it is preferable to detect the slope of the paper S relative to the paper conveying direction. For example, two detection units having the same structure as the detection unit 33 may be provided at different positions in the paper conveying direction. The slope of the paper S relative to the paper conveying direction can be obtained based on the positions of the side ends s1 of the paper S of the two detection units.

[0272] In addition, in each embodiment, the control of switching the conveyance of the second conveying path 38 and the conveyance of only the first conveying path 37 in the colorimetric mode and the non-colorimetric mode is illustrated. However, the image reading device 30 is not limited to this control. For example, the conveyance of the second conveying path 38 can also be performed in any of the colorimetric mode and the non-colorimetric mode. Furthermore, in this case, the conveying path of the image reading device 30 can also be composed of only the conveying path passing through the second conveying path 38. In this case, the conveying paths of the two systems can be reduced to one system, and the device structure can be simplified. In addition, there is no need for a device for switching the conveying path and its control.

[0273] Furthermore, even in the non-colorimetric mode, the paper slope correction can be performed by the correction unit 35. In this case, the conveyance direction of the paper S can be optimized even in the non-colorimetric mode.

[0274] Furthermore, even in the non-colorimetric mode, the paper can be detected by the detection unit 33. In this case, information on the conveyance state of the paper S can be obtained even in the non-colorimetric mode.

[0275] Furthermore, the detailed configuration of each device constituting the image forming apparatus 1 and the detailed operation of each device can be appropriately changed without departing from the gist of the present invention.

Claims

1. An image reading device, comprising: a conveying path for conveying a recording medium; a colorimetric unit that reads a colorimetric target image recorded on the recording medium conveyed on the conveying path; a detection unit that detects a position of the recording medium in a direction intersecting with a conveying direction of the recording medium; and The colorimetric control unit controls the colorimetric unit to read the colorimetric target image based on the detection result of the detection unit.

2. The image reading device according to claim 1, wherein: The colorimetric control section controls a reading position by the colorimetric section based on the detection result by the detection section.

3. The image reading device according to claim 1, wherein: The color measuring unit is movable in a direction intersecting the conveying direction.

4. The image reading device according to claim 3, wherein: The colorimetric control section adjusts a reading position by the colorimetric section in a direction intersecting the conveying direction, based on the detection result by the detection section.

5. The image reading device according to claim 3, wherein: A plurality of the colorimetric object images are recorded in the recording medium along a direction intersecting the conveying direction. The colorimetric section moves in a direction intersecting the conveying direction to read each of the colorimetric target images.

6. The image reading device according to claim 5, wherein: The colorimetric control section controls a position at which the colorimetric section starts reading the colorimetric target image, based on the detection result by the detection section.

7. The image reading device according to claim 5, wherein: The colorimetric control section adjusts the position of the colorimetric section in a direction intersecting the conveying direction before the colorimetric section starts reading the colorimetric target image, based on the detection result by the detection section.

8. The image reading device according to claim 1, wherein: The detecting section is located upstream of the color measuring section in the conveying direction.

9. The image reading device according to claim 1, wherein: The colorimetric control section can implement a colorimetric mode in which the colorimetric section reads the colorimetric target image, and a non-colorimetric mode in which the colorimetric target image is not read.

10. The image reading device according to claim 1, wherein: The image reading device includes a correction section located upstream of the color measuring section in the conveyance direction and configured to correct a slope of the recording medium conveyed on the conveyance path.

11. The image reading device according to claim 10, wherein: The detecting section is located downstream of the correcting section in the conveying direction.

12. The image reading device according to claim 11, wherein: The detection unit detects the position of the recording medium after the slope is corrected by the correction unit.

13. The image reading device according to claim 10, wherein: The colorimetric control unit is capable of implementing a colorimetric mode in which the colorimetric unit reads the colorimetric target image, and a non-colorimetric mode in which the colorimetric target image is not read. In the colorimetric mode, calibration by the calibrator and detection by the detector are performed, and in the non-colorimetric mode, at least one of calibration by the calibrator and detection by the detector is not performed.

14. The image reading device according to claim 13, wherein: The image reading device includes a conveyance control unit that, in the colorimetric mode, makes the conveyance speed of the recording medium at least when passing through the colorimetric unit lower than that in the non-colorimetric mode.

15. The image reading device according to claim 10, wherein: The colorimetric control unit controls the reading position based on the colorimetric unit based on the slope of the recording medium, wherein the slope of the recording medium is calculated based on a detection result obtained by the detection unit when the recording medium is in a conveying stop state after correction based on the correction unit, and a detection result obtained by the detection unit when the recording medium is in a conveying stop state when reading based on the colorimetric unit thereafter.

16. The image reading device according to claim 1, wherein: The colorimetric section includes a spectrophotometer.

17. An image forming apparatus comprising: An image forming unit that records an image on a recording medium; a conveying path for conveying the recording medium; a colorimetric section that reads a colorimetric target image recorded by the image forming section on the recording medium conveyed on the conveying path; a detection unit that detects a position of the recording medium in a direction intersecting with a conveying direction of the recording medium; and The colorimetric control unit controls the colorimetric unit to read the colorimetric target image based on the detection result of the detection unit.

18. The image forming apparatus according to claim 17, wherein: The image forming device comprises: a reading unit that reads the image recorded on the recording medium by the image forming unit; and The image control unit corrects image formation by the image forming unit based on a result of reading the image by the reading unit.

19. The image forming apparatus according to claim 18, wherein: The image control section corrects and performs image formation by the image forming section based on a reading result of the colorimetric target image by the colorimetric section and a reading result of the image by the reading section.

20. The image forming apparatus according to claim 17, wherein: The image forming apparatus includes a correction section located upstream of the color measuring section in the conveyance direction and configured to correct a slope of the recording medium conveyed on the conveyance path.

21. The image forming apparatus according to claim 20, wherein: The image forming device comprises: a reading unit that reads the image recorded on the recording medium by the image forming unit; and an image control unit that corrects image formation by the image forming unit based on a result of reading the image by the reading unit, The reading section is located upstream of the correction section and the detection section in the conveying direction.

22. The image forming apparatus according to claim 17, wherein: The image forming device comprises: a reading unit that reads the image recorded on the recording medium by the image forming unit; and an image control unit that corrects image formation by the image forming unit based on a result of reading the image by the reading unit, The reading section is located downstream of the color measuring section in the conveying direction.

23. The image forming apparatus according to claim 17, wherein: The colorimetric section includes a spectrophotometer.

24. An image reading method of an image reading device, comprising a conveying path for conveying a recording medium, a colorimetric unit for reading a colorimetric object image recorded on the recording medium conveyed on the conveying path, and a detecting unit for detecting a position of the recording medium in a direction intersecting with a conveying direction of the recording medium, wherein: The colorimetric section reads the colorimetric target image based on the detection result by the detection section.

25. A procedure, A computer of an image reading device having a conveying path for conveying a recording medium, a colorimetric unit for reading a colorimetric object image recorded on the recording medium conveyed on the conveying path, and a detection unit for detecting the position of the recording medium in a direction intersecting with the conveying direction of the recording medium, is configured to realize a function in which the colorimetric unit reads the colorimetric object image based on a detection result based on the detection unit.

Images