Reading device, image processing device, reading method, and program

Abstract

To provide a read image in which an inclination of a subject is corrected during transportation while restraining damage to the subject by utilizing electronic inclination correction instead of mechanical inclination correction when reading mixed subjects of different sizes.SOLUTION: A device includes an illumination unit that irradiates a subject with light, an imaging unit that receives light reflected by the subject to generate an image, a transport unit that transports the subject to a reading position of the imaging unit, a first inclination correction unit that mechanically corrects the inclination of the subject, a second inclination correction unit that electronically corrects the inclination of the image obtained from the imaging unit, and a switching unit that switches use or non-use of each of the first inclination correction unit and the second inclination correction unit. The switching unit uses the first inclination correction unit when the subject does not include objects of a plurality of sizes, but includes only objects of the same size, and uses the second inclination correction unit when the subject includes objects of a plurality of sizes.SELECTED DRAWING: Figure 6

Description

Technical Field

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

Background Art

[0002] Conventionally, in a reading device including a conveyance device that conveys a subject (for example, a document), techniques for correcting the inclination of a read image of the subject that occurs during conveyance by an electronic method or a mechanical method are known.

[0003] Patent Document 1 discloses a technique of increasing the abutting amount by setting the deceleration timing of a conveyance roller later for the purpose of more effectively performing mechanical inclination correction for a small size when reading a document in which a plurality of sizes are mixed.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional techniques for correcting image inclination, in the mechanical method, it is easy to damage the document depending on the paper size, etc., and in the electronic method, there is a problem that correction cannot be performed and an error occurs depending on the combination of the image acquisition width and the inclination angle.

[0005] The present invention has been made in view of the above, and aims to provide a read image in which damage to the subject is suppressed while using electronic inclination correction instead of mechanical inclination correction when reading a subject with mixed sizes, and the inclination during conveyance of the subject is corrected.

Means for Solving the Problems

[0006] In order to solve the above-described problems and achieve the object, the present invention includes an illumination unit that irradiates light onto a subject, an imaging unit that receives the light reflected by the subject and generates an image, a conveyance unit that conveys the subject to a reading position by the imaging unit, a first inclination correction unit that mechanically corrects the inclination of the subject, a second inclination correction unit that electronically corrects the inclination of the image obtained from the imaging unit, and a switching unit that switches between using and not using each of the first inclination correction unit and the second inclination correction unit. The switching unit uses the first inclination correction unit when the subject is of only the same size without including a plurality of types of sizes, and uses the second inclination correction unit when the subject includes a plurality of types of sizes.

Advantages of the Invention

[0007] According to the present invention, by using electronic inclination correction instead of mechanical inclination correction when reading a subject with mixed sizes, it is possible to suppress damage to the subject and provide a read image in which the inclination during conveyance of the subject is corrected.

Brief Description of the Drawings

[0008]

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[0009] Hereinafter, embodiments of a reading device, an image processing device, a reading method, and a program will be described in detail with reference to the accompanying drawings.

[0010] (First Embodiment) FIG. 1 is a diagram showing a configuration example of an image forming apparatus 1 according to the first embodiment. In FIG. 1, an image forming apparatus 1 which is an image processing apparatus is generally called a multi-function device having at least two functions among a copying function, a printer function, a scanner function, and a facsimile function.

[0011] The image forming apparatus 1 has an image reading apparatus 101 which is a reading device, and has an image forming unit 103 below it. Regarding the image forming unit 103, in order to explain the internal configuration, the external cover is removed to show the internal configuration.

[0012] The image reading apparatus 101 mounts an ADF (Automatic Document Feeder) 102 on the upper part of the apparatus main body 10. The ADF 102 is a document support unit that positions a document to be read at a reading position. The ADF 102 automatically conveys the document placed on the placement table to the reading position. The image reading apparatus 101 reads the document conveyed by the ADF 102 at a predetermined reading position. Further, the image reading apparatus 101 has a contact glass which is a document support unit for placing a document on its upper surface, and reads the document on the contact glass which is the reading position. Specifically, the image reading apparatus 101 is a scanner having a light source, an optical system, and a solid-state imaging device such as a CMOS image sensor inside, and reads the reflected light of the document illuminated by the light source with the solid-state imaging device through the optical system.

[0013] The image forming unit 103 includes a manual roller 104 that accepts manual feeding of recording paper, and a recording paper supply unit 107 that supplies the recording paper. The recording paper supply unit 107 has a mechanism for feeding out the recording paper from a multi-stage recording paper cassette 107a. The supplied recording paper is sent to the secondary transfer belt 112 via the registration roller 108.

[0014] The recording paper conveyed on the secondary transfer belt 112 has the toner image on the intermediate transfer belt 113 transferred thereto in the transfer unit 114.

[0015] Also, the image forming unit 103 includes an optical writing device 109, tandem type image forming units (Y, M, C, K) 105, an intermediate transfer belt 113, the secondary transfer belt 112, and the like. The image forming unit 103 forms the image written by the optical writing device 109 as a toner image on the intermediate transfer belt 113 through the image forming process by the image forming unit 105.

[0016] Specifically, the image forming units (Y, M, C, K) 105 rotatably include four photosensitive drums (Y, M, C, K), and each photosensitive drum is provided with an image forming element 106 including a charging roller, a developing device, a primary transfer roller, a cleaner unit, and a discharger around it. The image forming element 106 functions on each photosensitive drum, and the image on the photosensitive drum is transferred onto the intermediate transfer belt 113 by each primary transfer roller.

[0017] The intermediate transfer belt 113 is stretched and disposed between the nips of each photosensitive drum and each primary transfer roller by a driving roller and a driven roller. The toner image primarily transferred onto the intermediate transfer belt 113 is secondarily transferred onto the recording paper on the secondary transfer belt 112 by a secondary transfer device due to the running of the intermediate transfer belt 113. The recording paper is conveyed to the fixing device 110 due to the running of the secondary transfer belt 112, and the toner image is fixed as a color image on the recording paper. Thereafter, the recording paper is discharged to an external paper discharge tray. In the case of double-sided printing, the front and back of the recording paper are reversed by the reversing mechanism 111, and the reversed recording paper is sent onto the secondary transfer belt 112.

[0018] Note that the image forming unit 103 is not limited to forming an image by the electrophotographic method as described above, and may form an image by an inkjet method.

[0019] Next, the image reading device 101 will be described.

[0020] FIG. 2 is a diagram showing an example of the device configuration of the image reading device 101. The device main body 10 of the image reading device 101 has a contact glass 11 on its upper surface. The image reading device 101 has a light source 13, a first carriage 14, a second carriage 15, a lens unit 16, a sensor board 17, etc. inside the device main body 10. In FIG. 2, the first carriage 14 has a light source 13 and a reflection mirror 14-1, and the second carriage 15 has reflection mirrors 15-1 and 15-2.

[0021] The light of the light source 13 is irradiated onto the object to be read, and the reflected light from the object to be read is reflected by the mirror 14-1 of the first carriage 14 and the mirrors 15-1 and 15-2 of the second carriage 15 and enters the lens unit 16, and an image of the object to be read is formed on the light receiving surface on the sensor board 17 from the lens unit 16. The sensor board 17 has an imaging unit 40 which is a line sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary MOS). The sensor board 17 sequentially converts the image of the object to be read formed on the light receiving surface in the imaging unit 40 into an electrical signal. The reference white board 12 is a white density reference member that is read for correction of changes in the light amount of the light source 13 and variations in pixels (pixel circuits) of the imaging unit 40.

[0022] The image reading device 101 is provided with a control board in the device main body 10, and controls each part of the device main body 10 and each part of the ADF 102 to read the object to be read by a predetermined reading method. The object to be read is, for example, a recording medium on which characters, patterns, etc. are formed. Hereinafter, this recording medium will be referred to as a document. The document corresponds to the "subject", and will be described as paper or a transparent sheet (such as an OHP sheet) as an example, but is not limited thereto.

[0023] The image reading device 101 reads the document 100 in a sheet-through manner using the ADF 102. The ADF 102 is an example of a "transport unit". In the configuration shown in FIG. 2, the image reading device 101 separates the documents 100 one by one from the stack of documents on the tray 21 of the ADF 102 by the pickup roller 22 and transports the document 100 to the transport path 23, reads the surface of the document 100 to be read at the reading position of the reading unit, and discharges the document 100 to the discharge tray 25. The transport of the document 100 is performed by the rotation of various transport rollers 24.

[0024] Among the various transport rollers 24, a pair of rollers that perform primary abutment alignment (so-called skew correction) on the fed document 100 and pull out and transport the aligned document 100 are called pull-out rollers 24a. A butting sensor 51 is provided near the pull-out rollers 24a. The pull-out rollers 24a constitute a mechanical tilt correction unit 70, which is a first tilt correction unit, together with a drive mechanism 24b (see FIG. 3) including a drive circuit.

[0025] Here, FIG. 3 is a diagram showing an example of the arrangement of the mechanical tilt correction unit 70. As an example of the configuration of the mechanical tilt correction unit 70 of the present embodiment, as shown in FIG. 3, a pair of pull-out rollers 24a (abutting members) provided on the transport path 23 for the document 100 are mentioned. The pull-out rollers 24a can have their operations controlled by the drive mechanism 24b.

[0026] When an instruction to make it effective is received from the control unit 41 (see FIG. 5), the mechanical tilt correction unit 70 stops the rotation of the abutting pull-out rollers 24a by controlling the drive mechanism 24b. Thereby, the mechanical tilt correction unit 70 bends the document 100 by abutting the leading edge of the document 100 between the pull-out rollers 24a, and corrects the tilt of the document 100.

[0027] On the other hand, when an instruction to disable it is given from the control unit 41 (see FIG. 5), the mechanical tilt correction unit 70 keeps the pull-out roller 24a rotating by controlling the drive mechanism 24b, or increases the interval between the pull-out rollers 24a by controlling the drive mechanism 24b. Thereby, the mechanical tilt correction unit 70 conveys the document 100 without stopping the document 100 with the pull-out roller 24a for abutment.

[0028] Returning to FIG. 2, the tray 21 has a movable document table 211 that pivots in the directions of a and b in the figure with the base end as a fulcrum, and a pair of side guide plates 212 that position the document 100 in the left-right direction with respect to the paper feed direction. By pivoting the movable document table 211, the front end of the document 100 in the paper feed direction is adjusted to an appropriate height.

[0029] Also, on the tray 21, document length detection sensors 213 and 214 for detecting whether the document 100 is in the vertical or horizontal orientation are provided at intervals in the paper feed direction. Note that as the document length detection sensors 213 and 214, a reflection type sensor that detects without contact by optical means or a contact type actuator type sensor may be used.

[0030] The pair of side guide plates 212 are slidable in the left-right direction with respect to the paper feed direction and are configured to be able to support documents 100 of different sizes. A document set sensor 215 for detecting that the document 100 is placed on the tray 21 is provided on the pair of side guide plates 212.

[0031] Also, a document width sensor 52 as a document size detection unit is provided in the conveyance path 23 on the downstream side in the document conveyance direction of the pull-out roller 24a.

[0032] The image reading device 101 passes the document 100 between the reading window 19 and the background portion 26 with, for example, the first carriage 14 and the second carriage 15 moved to and fixed at a predetermined home position. The reading window 19 is a slit-shaped reading window provided in a part of the contact glass 11. The background portion 26 is a member located at a position facing the reading window 19. The reading unit irradiates the light of the light source 13 onto the first surface (front surface or back surface) of the document 100 facing the reading window 19 while the document 100 passes through the reading window 19, and receives the reflected light with the imaging unit 40 on the sensor board 17 to read an image. The background portion 26 may have a size such that it is included in the imaging range of the imaging unit 40, and is, for example, a sheet metal or a roller.

[0033] Here, the light source 13, the background portion 26, the optical system (mirrors 14-1, 15-1, 15-2, lens unit 16, etc.) that guides the reflected light from the document 100 to the imaging unit 40 of the sensor board 17, and the imaging unit 40, etc. will be described as the reading unit (first reading unit). The configuration of the reading unit will be described again with reference to FIG. 5.

[0034] When performing double-sided reading of the document 100, for example, it is implemented by providing a reversing mechanism for reversing the front and back. The image reading device 101 reverses the document 100 by providing a reversing mechanism and reads the second surface of the document 100 at the reading position (reading window 19) of the reading unit. Further, not limited to the reversing mechanism, other configurations, for example, providing a second reading unit, etc. may be used to read the second surface. For example, after passing through the reading window 19, the second surface of the document 100 is read by a reading unit (second reading unit) provided on the back side of the document 100. In this case, the member located at the position facing the reading sensor corresponds to the background portion 26 (see FIG. 4).

[0035] In the configuration of the image reading apparatus 101 of this example, flatbed scanning is also possible. Specifically, the ADF 102 is lifted to expose the contact glass 11, and the document 100 is placed directly on the contact glass 11. Then, the ADF 102 is lowered to its original position, and the back surface of the document 100 is pressed at the lower part of the ADF 102. In the flatbed mode, since the document 100 is fixed, the carriage (the first carriage 14 and the second carriage 15) moves relative to the document 100 for scanning. The first carriage 14 and the second carriage 15 are driven by the scanner motor 18 to scan in the sub-scanning direction of the document 100. For example, the first carriage 14 moves at a speed V, and at the same time, the second carriage 15 moves in conjunction with it at a speed of 1 / 2V, which is half the speed of the first carriage 14, to read the first surface of the document 100 on the contact glass 11 side. In this case, the lower part of the ADF 102 (the member that presses the document 100 from the back) corresponds to the background part 26 (see FIG. 4).

[0036] Note that in this example, the first carriage 14, the second carriage 15, the lens unit 16, the sensor board 17, etc. are shown separately, but they may be provided individually or as an integrated sensor module integrated together.

[0037] FIG. 4 is a diagram for explaining an example of the configuration of the reading unit 30. As an example, it shows the configuration of the reading unit 30 (the first reading unit) that reads the first surface of the document 100 and the conveyance mechanism. As shown in FIG. 4, the document 100 is sent by various conveyance rollers 24 and passes between the reading position (the reading window 19) of the contact glass 11 and the background part 26.

[0038] The reading unit 30 has a set background part 26. When the light source 13 is lit, while the document 100 passes through the reading window 19, the reflected light of the light from the light source 13 from the first surface of the document 100 facing the reading window 19 is received by the imaging unit 40 on the sensor board 17 through the path indicated by the dotted line in FIG. 4 to read the image.

[0039] Note that the configuration of the reading unit is not limited to the configuration of this first reading unit. It may be appropriately modified according to the configuration of a method of reading with a close-contact type image sensor like a second reading unit or other image reading apparatuses.

[0040] As shown in Fig. 4, the light source 13 of this embodiment is composed of a visible light source 13a and an invisible light source 13b, and is an illumination unit that irradiates a subject with visible light and invisible light. The visible light source 13a irradiates the subject and the background portion 26 with visible light. The invisible light source 13b irradiates the subject and the background portion 26 with invisible light. It is effective to use infrared light as the invisible light source 13b. Generally, the visible light wavelength range is 380 to 750 nm, and 750 nm and above is the infrared wavelength range, which is the wavelength range of invisible light.

[0041] Note that in this embodiment, the invisible light source 13b irradiates invisible light in the infrared wavelength range of 750 nm or more, but it is not limited to this, and it may irradiate invisible light in the ultraviolet wavelength range of 380 nm or less.

[0042] Fig. 5 is a block diagram showing the electrical connection of each part constituting the image reading apparatus 101. As shown in Fig. 5, the image reading apparatus 101 includes, in addition to the imaging unit 40 and the light source 13 described above, a control unit 41, a light source driving unit 42, an image processing unit 43, and an operation unit 44. The control unit 41 controls the imaging unit 40, the light source driving unit 42, the image processing unit 43, and the operation unit 44. The light source driving unit 42 drives the light source 13 according to the control of the control unit 41. The imaging unit 40 transfers a signal to the image processing unit 43 arranged in the subsequent stage. The operation unit 44 is, for example, a display with a touch panel.

[0043] The imaging unit 40 includes an infrared light image sensor 40b that functions as an invisible image reading unit, and a visible light image sensor 40a that functions as a visible image reading unit. The imaging unit 40 receives visible light and infrared light reflected by a subject, and captures a visible image and an infrared image. More specifically, the infrared light image sensor 40b acquires an infrared image (an image in the infrared wavelength region) by reading infrared reflected light from a subject that is a part of infrared light. The visible light image sensor 40a acquires a visible image (an image in the visible wavelength region) by reading visible reflected light from a subject that is a part of visible light. The infrared light image sensor 40b and the visible light image sensor 40a are sensors for a reduction optical system, and are, for example, CMOS image sensors or the like.

[0044] Note that the visible light image sensor 40a and the infrared light image sensor 40b may have an integrated configuration. As a result, a smaller configuration can be achieved, and the reading positions of visible light and infrared light are closer, enabling extraction and restoration of highly accurate disappearance information. That is, there is no image shift due to multiple readings, and correction can be performed with high positional accuracy.

[0045] The image processing unit 43 performs various image processes according to the purpose of use of the image data. Note that the control unit 41 and the image processing unit 43 may be realized by a hardware circuit, or may be realized by a CPU executing a program.

[0046] Here, FIG. 6 is a block diagram showing the functional configuration of each unit constituting the image reading device 101. As shown in FIG. 6, the image processing unit 43 includes a feature amount detection unit 431 and an inclination correction unit 432. The inclination correction unit 432, together with the feature amount detection unit 431, constitutes an electronic inclination correction unit 80 that is a second inclination correction unit.

[0047] The image processing unit 43 detects the feature amount of the subject or the background portion 26 by the feature amount detection unit 431 from at least one of the visible image and the invisible image obtained by the image reading device 101. Examples of the feature amount include, for example, an edge between the background portion 26 and the document 100. The image processing unit 43 uses the detected feature amount for the correction process of the image itself, although the details will be described later.

[0048] The feature amount detection unit 431 functions as an edge detection unit that detects the edge of the subject in the main scanning direction. More specifically, the feature amount detection unit 431 detects an edge by methods such as detecting an edge from the density difference between the read document 100 and the background portion 26, or detecting a shadow between the document 100 and the background portion 26. The feature amount detection unit 431 regards a location where the change amount of the image density exceeds a predetermined value as an edge of the document 100. Here, edge detection means detecting the edges of the left and right sides of the document 100 or detecting the edges of the detectable range of the main scanning area at the upper side of the document 100.

[0049] The inclination correction unit 432 receives the edge detection result of the feature amount detection unit 431 and corrects the inclination of the document 100.

[0050] Here, the difference in the spectral reflection characteristics due to the medium in the imaging unit 40 will be described.

[0051] FIG. 7 is a diagram showing the difference in the spectral reflection characteristics due to the medium. FIG. 7 is a diagram showing the spectral reflection characteristics of two types of plain papers, paper type A and paper type B, which are generally used as documents and the background portion 26, which are the reading targets of the image reading device 101. In FIG. 7, the graph of the one-dot chain line is the graph of the spectral reflection characteristics of the plain paper (paper type A), the graph of the dotted line is the graph of the spectral reflection characteristics of the plain paper (paper type B), and the graph of the solid line is the graph of the spectral reflection characteristics of the background portion 26.

[0052] As shown in FIG. 7, it can be seen that in the visible wavelength range, the reflectance of the background portion 26, which is a white background, is higher than that of the plain paper (paper type A), but in the near-infrared (NIR) wavelength range, the reflectance of the background portion 26 is lower than that of the plain paper (paper type A).

[0053] Also, as shown in FIG. 7, it can be seen that the reflectance of the background portion 26 is higher than that of plain paper (paper type B) in both the visible wavelength region and the near-infrared (NIR) wavelength region.

[0054] Here, FIG. 8 is a diagram exemplarily showing the difference between a visible image and an invisible image. As shown in FIG. 8, when the reflected light is read by the imaging unit 40, the spectral reflection characteristics are different between the background portion 26 and the document, and images having different feature amounts are obtained for visible light and invisible light. Therefore, depending on the type of the subject and the type of the background portion 26, it is easy to obtain the target feature amount by presetting the image to be detected as either a visible image or an invisible image in advance.

[0055] For example, in the case of the example shown in FIG. 8, since the spectral reflection characteristic difference between the background portion 26 and the paper type A is larger in the invisible image than in the visible image, the detection target of the feature amount can be set as the invisible image, and conversely, the paper type B can be set as the visible image.

[0056] Note that the extraction of the feature amount may be performed from only one of the visible image or the invisible image, or the feature amount may be extracted from both the visible image and the invisible image, and then selected or integrated from the results.

[0057] Subsequently, an edge detection example of the document 100 as the subject by the feature amount detection unit 431 and a correction example of the inclination of the document by the inclination correction unit 432 will be described.

[0058] FIG. 9 is a diagram showing an example of edge detection of a subject, FIG. 10 is a diagram showing an example of correction of the inclination of a document, and FIG. 11 is a diagram showing information obtained from the edge of a subject. For example, as shown in FIG. 9, when extracting an edge between the background portion 26 and the document 100 from an image, it is preferable to reduce the reflectance of the background portion 26 and use an invisible image. Also, as shown in FIG. 10, when correcting the inclination and position of the document and cropping the document image, it is preferable to reduce the reflectance of the background portion 26 and use an invisible image. When reading with invisible light in this way, since the invisible light reflectance of the background portion 26 is low, a bright image of the document 100 and a dark image of the background portion 26 can be obtained. Since the difference between the document 100 and the background portion 26 can be clearly understood, edges can be easily detected. That is, the density difference between the document 100 and the background portion 26 can be widened, and edge detection can be performed with higher accuracy.

[0059] As shown in FIG. 11, an edge refers to the boundary between the document 100, which is the subject, and the background portion 26. By detecting such an edge, as shown in FIG. 11, the position, inclination, size, etc. of the document 100, which is the subject, can be recognized.

[0060] More specifically, the inclination correction unit 432 extracts based on the feature amount (edge) of the image detected by the feature amount detection unit 431 for the document area edge (end portion), and calculates the inclination angle of the document from the coordinates of the end portion. The inclination correction unit 432 can calculate the inclination of the document area from the positions of the pixels constituting the edge. For example, as shown in FIG. 11, the inclination correction unit 432 obtains the inclination of the regression line of the edge by setting the inclination of the straight line as (yn - y1) / (xn - x1). Note that the inclination correction unit 432 may also obtain the inclination by other methods such as using the least squares method to obtain the inclination of the regression line of the edge.

[0061] Based on the calculated inclination angle of the edge, the inclination correction unit 432 performs a rotation process on the image of the document area portion and provides a read image equivalent to the case where the document has no inclination.

[0062] FIG. 12 is a diagram exemplarily showing a method of edge detection. As a method of edge detection, as shown in FIG. 12(a), for example, a method of applying a first derivative filter to the entire image and binarizing it based on whether each pixel exceeds a predetermined threshold value can be mentioned. At that time, depending on the threshold value, horizontal edges may appear continuously vertically by several pixels (the reverse is also true). This is mainly because the edge blurs due to the MTF characteristics of the optical system. Therefore, as shown in FIG. 12(b), in order to obtain representative edge pixels for calculating the regression line formula and size detection described later, for example, there is a method of selecting the center of continuous pixels (part a shown in FIG. 12(b)).

[0063] FIG. 13 is a diagram showing an example of a feature amount using an edge. As the feature amount, it may not be the edge itself extracted from the image, but may be one using the edge. As an example, as shown in FIG. 13, a regression line formula calculated using the least squares method or the like from the extracted edge point group, and the area (set of positions) inside the edge can be mentioned. Regarding the regression line formula, there is also a method of obtaining one linear formula from all edge information for each side, but there is also a method of calculating linear formulas by dividing into a plurality of regions and selecting or integrating representative ones. In that case, as a method of deriving the final linear formula, a straight line whose slope is the median value and a method of obtaining the average value of each linear formula can be mentioned.

[0064] FIG. 14 is a diagram showing the selection of a linear formula in the regression line formula. By calculating linear formulas by dividing into a plurality of regions and selecting or integrating representative ones, as shown in FIG. 14, even when there is damage such as the edge of the original manuscript 100 being damaged, the slope of the original manuscript 100 that is the subject can be correctly recognized.

[0065] As in the above processing, the feature amount detection unit 431 can detect the area of the original manuscript 100 that is the subject by extracting the edge of the original manuscript 100 that is the subject as a feature amount.

[0066] As shown in FIG. 6, the control unit 41 includes a switching unit 411.

[0067] The switching unit 411 switches between using the mechanical tilt correction unit 70 and the electronic tilt correction unit 80. More specifically, when the document 100, which is the subject, is of only the same size without including multiple types of sizes, the mechanical tilt correction unit 70 is used, and when the document 100 includes multiple types of sizes, the electronic tilt correction unit 80 is used.

[0068] Here, regarding the problem that damage is likely to occur to the document, which may occur when reading a document (a document with mixed sizes) consisting of a plurality of different sizes, in a conventional image reading apparatus, an explanation will be given.

[0069] Here, FIG. 15 is a diagram showing an example of the configuration of a conventional image reading apparatus, FIG. 16 is a diagram showing an example of contact between a roller and the edge of a document, and FIG. 17 is a diagram showing an example where tilt correction is not effective.

[0070] As shown in FIG. 15, conventionally, in order to suppress the tilt of a document, a member (side fence in the example of FIG. 15) that surrounds both ends of the document on the document placement unit and a mechanical tilt correction unit 70 (pull-out roller 24a) are provided in the configuration of an image reading apparatus. In the example shown in FIG. 15, when reading a document composed of multiple types of sizes, the largest document (document A shown in FIG. 15) can obtain the effect of the side fence, but a document B smaller than document A cannot receive the effect of suppressing the tilt of the document by the side fence. Also, for document B, not only may the tilt occur, but the placement position may also shift.

[0071] Regarding the mechanical tilt correction unit 70, as shown in FIG. 15, for example, a pull-out roller 24a (composed of a plurality of rollers) is provided in the width direction of the document, and the tilt of the document is corrected by bringing the conveyed document into contact with the pull-out roller 24a. Note that the width and the location of the pull-out roller 24a are determined based on the processing accuracy of the parts and the size of the document to be read, etc.

[0072] The following two points can be cited as problems with such a configuration. ·Depending on the displacement or inclination of the placed document, damage may be caused to the document due to contact with the mechanical inclination correction unit 70 (see FIG. 16). ·Depending on the displacement or size of the placed document, mechanical inclination correction by the mechanical inclination correction unit 70 may not be sufficient to correct the inclination in some cases. (See FIG. 17).

[0073] Therefore, the image reading apparatus 101 of the present embodiment includes a mechanical inclination correction unit 70 and an electronic inclination correction unit 80, and has a switching unit 411 that switches the execution of the two inclination correction units (mechanical inclination correction unit 70, electronic inclination correction unit 80).

[0074] And the switching unit 411 performs the control described below. More specifically, when reading a document with mixed sizes, the switching unit 411 does not use the mechanical inclination correction unit 70, but uses the electronic inclination correction unit 80. Further, when not reading a document with mixed sizes, the switching unit 411 uses the mechanical inclination correction unit 70. Thereby, it is possible to provide the image reading apparatus 101 corresponding to the inclination correction of the document while suppressing document damage that is likely to occur when reading a document with mixed sizes. This point will be described in detail below.

[0075] Here, FIG. 18 is a flowchart schematically showing the flow of the image reading process. As shown in FIG. 18, the switching unit 411 determines whether documents of a plurality of sizes are mixed (step S1).

[0076] FIG. 19 is a diagram showing an example of the display form on the operation unit 44. As shown in FIG. 19, the operation unit 44 realizes a user interface that allows the user to set in advance to read documents of a plurality of sizes simultaneously, or a usage method assumed to be reading a plurality of sizes. In the example shown in FIG. 19, the operation unit 44 can specify "automatic detection (mixed sizes)" 44a as the reading size. When such "automatic detection (mixed sizes)" 44a is specified, the switching unit 411 determines that documents of a plurality of sizes are mixed.

[0077] The switching unit 411 switches whether to execute the mechanical inclination correction unit 70 depending on whether an option in "automatic detection (mixed sizes)" 44a as the reading size is selected on the operation unit 44. For example, when the corresponding option (for example, reading a plurality of manuscripts including an irregular size manuscript) is selected, the mechanical inclination correction unit 70 is deactivated and only the electronic inclination correction unit 80 is executed.

[0078] In this way, by the operation unit 44, the user can be guided so as to obtain suppression of manuscript damage that is likely to occur when the mechanical inclination correction unit 70 is executed during reading of manuscripts of multiple sizes. Alternatively, the user can use this mode when they do not want to damage the manuscript.

[0079] When the switching unit 411 determines that a plurality of manuscripts of different sizes are mixed and a manuscript composed of a plurality of sizes is to be read (Yes in step S1), the control unit 41 deactivates the mechanical inclination correction unit 70 and executes image reading of the manuscript (step S2).

[0080] Subsequently, the switching unit 411 controls the electronic inclination correction unit 80 (feature detection unit 431 and inclination correction unit 432) to perform electronic inclination correction on the read image (step S3).

[0081] For a regular size manuscript, since it is possible to estimate where the manuscript 100 passes along the conveyance path 23, the arrangement of the members used in the mechanical inclination correction unit 70 can be determined accordingly. However, for an irregular size manuscript, it is difficult to estimate where the easily damaged part such as the edge of the manuscript 100 passes on the conveyance path 23. Therefore, depending on the combination of the member arrangement and the manuscript size, the possibility of manuscript damage is higher than that of a regular manuscript.

[0082] Therefore, in the present embodiment, when the user of the device sets an irregular size manuscript 100 on the operation unit 44, the inclination correction by the mechanical inclination correction unit 70 is not performed, and damage to the manuscript 100 that is likely to occur when the mechanical inclination correction is executed can be prevented.

[0083] Next, the control unit 41 determines whether there is no next manuscript to be read (step S4).

[0084] When the control unit 41 determines that there is a next manuscript to be read (No in step S4), it returns to step S2 and executes image reading of the next manuscript. Also, when the control unit 41 determines that there is no next manuscript to be read (Yes in step S4), it ends the process.

[0085] On the other hand, when the switching unit 411 determines that the manuscript is not a mixed load of manuscripts of a plurality of sizes but is composed of a single size and reads the manuscript (No in step S1), it controls the mechanical inclination correction unit 70 to perform mechanical inclination correction on the read image (step S5).

[0086] For example, depending on the combination of the inclination of the manuscript and the width of the acquired image, inclination correction may not be possible with only the electronic inclination correction by the electronic inclination correction unit 80, and there may be an error. Therefore, when reading a single manuscript size with a low possibility of manuscript damage due to the execution of mechanical inclination correction by the mechanical inclination correction unit 70, the switching unit 411 controls the mechanical inclination correction unit 70 to perform mechanical inclination correction. With this configuration, it is possible to provide the image reading apparatus 101 that performs inclination correction while suppressing the frequency of occurrence of errors compared to the correction by the electronic inclination correction unit 80 alone.

[0087] FIG. 20 is a diagram showing an example in which the electronic inclination correction unit 80 is considered to be ineffective. As a method for estimating the inclination, for example, a method of estimating the inclination from the upper left corner portion of the manuscript area can be considered. However, in the case shown in FIG. 20, there is a problem in the conventional technology that the inclination cannot be estimated because the corners of the manuscript image cannot be detected and it is regarded as an error. Even if the inclination can be calculated, there is also a problem that the part where the image of the manuscript area is partially missing cannot be repaired.

[0088] Subsequently, the control unit 41 executes image reading of the manuscript (step S6).

[0089] Next, the control unit 41 determines whether there is no next original to be read (step S7). When the control unit 41 determines that there is a next original to be read (No in step S7), it returns to step S5 and executes image reading of the next original. Also, when the control unit 41 determines that there is no next original to be read (Yes in step S7), it ends the process.

[0090] With this configuration, even when reading originals of multiple types of sizes, it is possible to read the original while suppressing the possibility of damage to the original 100 and correcting the inclination at the time of original setting.

[0091] Also, as a secondary merit in the case of using only the electronic inclination correction by the electronic inclination correction unit 80, there is silence during image reading. For example, there is an abutting operation as the mechanical inclination correction unit 70, but in the case of the abutting operation, a collision sound between the original 100 and the abutting member (such as the pull-out roller 24a) occurs during execution and becomes noise. When using only the electronic inclination correction unit 80 without executing the mechanical inclination correction unit 70, this noise does not occur, so it is excellent in silence.

[0092] As described above, according to this embodiment, when the original 100 includes multiple types of sizes, the mechanical inclination correction unit 70 is not used, and the electronic inclination correction unit 80 is used. As described above, in the configuration of the conventional image reading apparatus, when using the mechanical inclination correction unit 70 during reading of a mixed-size original, there is a high possibility of damage to the original 100. However, according to this configuration, by using the electronic inclination correction of the electronic inclination correction unit 80 instead of the mechanical inclination correction of the mechanical inclination correction unit 70 during reading of the mixed-size original, damage to the original can be suppressed, and a read image with the inclination during original conveyance corrected can be provided. Also, as a secondary effect, when not using the mechanical inclination correction of the mechanical inclination correction unit 70, it is more excellent in silence than when using it.

[0093] In addition, in this embodiment, when the original document 100 only includes the same type of size and does not include multiple types of sizes, the mechanical inclination correction of the mechanical inclination correction unit 70 is used. However, the present invention is not limited to this. When the original document 100 only includes the same type of size and does not include multiple types of sizes, the switching unit 411 may use both the mechanical inclination correction unit 70 and the electronic inclination correction unit 80.

[0094] There are restrictions on the inclination of the original document 100 that can be supported by the electronic inclination correction by the electronic inclination correction unit 80. Therefore, by suppressing the inclination in advance using the mechanical inclination correction by the mechanical inclination correction unit 70 and then performing the electronic inclination correction by the electronic inclination correction unit 80, compared with an image reading apparatus using either the mechanical inclination correction unit 70 or the electronic inclination correction unit 80, inclination correction with a wider range of correspondence can be performed.

[0095] (Second Embodiment) Next, the second embodiment will be described.

[0096] The second embodiment is different from the first embodiment in that, by using the detection result of the original document width sensor 52 to determine whether multiple sizes of original documents are mixed, the size mixing is not determined first, but the size mixing is determined midway in the automatic mode. In the following description of the second embodiment, the description of the same parts as those in the first embodiment will be omitted, and the parts different from the first embodiment will be described.

[0097] Here, FIG. 21 is a block diagram showing the functional configuration of each part constituting the image reading apparatus 101 according to the second embodiment, and FIG. 22 is a diagram showing an arrangement example of the document width sensor 52. As shown in FIG. 21, the image reading apparatus 101 includes a document width sensor 52. The output of the document width sensor 52 is input to the control unit 41. As shown in FIG. 22, the document width sensor 52 includes, as an example, light receiving elements (52a, 52b, 52c) arranged in a plurality in the width direction of the document 100 in accordance with the size of the standard document of each document 100 from the side guide plate 212 serving as a document placement reference. The document width sensor 52 detects the document width of the document 100 based on the light reception result from the irradiation light provided at opposite positions across the conveyance path 23. Note that the length of the document 100 in the conveyance direction is detected from the motor pulses when the leading end and the trailing end of the document 100 are read by the abutment sensor 51 provided near the pull-out roller 24a.

[0098] As described above, the image reading apparatus 101 of the present embodiment can detect the width of the document 100 using the document width sensor 52.

[0099] As shown in FIG. 22, the document width sensor 52 is composed of, as an example, a plurality of light receiving elements (52a, 52b, 52c) arranged in the width direction of the document 100. The light receiving elements (52a, 52b, 52c) of the document width sensor 52 are placed at positions where it is possible to determine which standard size the document 100 is. Therefore, when a standard size document 100 passes through, the document size of the document 100 is determined from the position information of the light receiving elements of the document width sensor 52 that have reacted.

[0100] The document width sensor 52 is provided upstream on the conveyance path 23 from the reading unit, and estimates the size of the document 100 from the values of the light receiving elements (52a, 52b, 52c) of the document width sensor 52.

[0101] The switching unit 411 determines that the document 100 is composed of a plurality of types of sizes based on the size of the document obtained from the document width sensor 52. More specifically, the switching unit 411 performs the following comparison after reading one image. · The read manuscript size obtained from the manuscript width sensor 52 · The size of the next manuscript to be read, obtained from the manuscript width sensor 52 If the above two points are different, it is determined that reading manuscripts of multiple sizes is being performed, and the switching unit 411 performs control to disable the mechanical tilt correction unit 70.

[0102] Here, FIG. 23 is a flowchart schematically showing the flow of the image reading process.

[0103] As shown in FIG. 23, first, the switching unit 411 acquires the manuscript size of the read manuscript 100 obtained from the manuscript width sensor 52 during the reading of the first manuscript (step S11). The reason for acquiring the manuscript size of the read manuscript 100 in this way is that it is necessary when there is a next manuscript 100.

[0104] Next, the switching unit 411 controls the mechanical tilt correction unit 70 to perform mechanical tilt correction on the read image (step S12).

[0105] Subsequently, after the control unit 41 executes the image reading of the manuscript (step S13), it determines whether there is a next manuscript to be read (step S14).

[0106] If the control unit 41 determines that there is no next manuscript 100 (No in step S14), the process ends.

[0107] On the other hand, if the control unit 41 determines that there is a next manuscript 100 (Yes in step S14), it acquires the manuscript size of the next manuscript 100 to be read from the manuscript width sensor 52 (step S15).

[0108] Then, the switching unit 411 compares the manuscript size of the next manuscript 100 to be read with the manuscript size of the previously read manuscript 100 and determines whether it is different from the manuscript size of the previous manuscript 100 (step S16).

[0109] When the switching unit 411 determines that the size of the current original document 100 is different from that of the previous one (Yes in step S16), the control unit 41 invalidates the mechanical tilt correction unit 70 to avoid document damage on the assumption that original documents of multiple sizes are mixed, and performs image reading of the original document (step S2).

[0110] Subsequently, the switching unit 411 controls the electronic tilt correction unit 80 (feature detection unit 431 and tilt correction unit 432) to perform electronic tilt correction on the read image (step S3).

[0111] Next, the control unit 41 determines whether there is a next original document to be read (step S4).

[0112] When the control unit 41 determines that there is a next original document to be read (No in step S4), it returns to step S2 and performs image reading of the next original document. When the control unit 41 determines that there is no next original document to be read (Yes in step S4), it ends the process. That is, until there is no next original document to be read, "original document image reading" → "electronic tilt correction" is repeated. That is, once this pattern is entered, mechanical tilt correction is not used thereafter.

[0113] On the other hand, when the switching unit 411 determines that the size of the current original document 100 is not different from that of the previous one (No in step S16), the control unit 41 can state that it is a single size at least until the next original document 100 to be read, and thus controls the mechanical tilt correction unit 70 to perform mechanical tilt correction on the read image (step S5).

[0114] Subsequently, the control unit 41 performs image reading of the original document (step S6).

[0115] Next, the control unit 41 determines whether there is a next original document to be read (step S7). When the control unit 41 determines that there is a next original document to be read (No in step S7), it returns to step S15 and acquires the original document size of the original document 100 to be read next. Further, when the control unit 41 determines that there is no next original document to be read (Yes in step S7), it ends the process.

[0116] As described above, according to the present embodiment, although the first several sheets are in contact, after it is determined that the original document 100 includes a plurality of original documents of different sizes, it is possible to perform electronically corrected image reading while avoiding damage to the original document 100 that is likely to occur when using the mechanical inclination correction unit 70 during original document reading.

[0117] In the first embodiment, when a predetermined operation is performed on the operation unit 44, the original document 100 operates as including a plurality of different sizes. In the present embodiment, the configuration does not include performing a predetermined operation on the operation unit 44, and the original document width sensor 52 automatically determines that the original document 100 is a plurality of sizes, and the same effect can be obtained, and the configuration has improved convenience.

[0118] In the present embodiment, as shown in FIG. 22, the original document width sensor 52 arranges a plurality of light receiving elements (52a, 52b, 52c) in the width direction of the original document 100 in accordance with the size of the standard original document of each original document 100 from the side guide plate 212, but the present invention is not limited thereto.

[0119] For example, as shown in FIG. 24, the original document width sensor 52 may arrange a plurality of light receiving elements (52a, 52b, 52c, 52d, 52e, 52f) separately on the left and right of the conveyance path 23.

[0120] Further, as shown in FIG. 25, the original document width sensor 52 arranges a plurality of light receiving elements (52a, 52b, 52c) in the conveyance path 23, and installs a guide plate sensor 61 having a plurality of light receiving elements (61a, 61b, 61c) on the side guide plate 212 side of the tray 21 to detect the position of the slid side guide plate 212.

[0121] The program executed by the image forming apparatus 1 of each of the above embodiments is provided by being recorded on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, a DVD (Digital Versatile Disc) in a file in an installable format or an executable format.

[0122] Also, the program executed by the image forming apparatus 1 of each of the above embodiments may be configured to be stored on a computer connected to a network such as the Internet and downloaded via the network. Further, the program executed by the image forming apparatus 1 of each of the above embodiments may be configured to be provided or distributed via a network such as the Internet. Also, the program executed by the image forming apparatus 1 of each of the above embodiments may be configured to be provided by being pre-embedded in a ROM or the like.

[0123] The program executed by the image forming apparatus 1 of each of the above embodiments has a module configuration including the above-described respective parts (switching part 411). As actual hardware, the CPU (processor) reads the program from the above storage medium and executes it, so that the above respective parts are loaded onto the main storage device, and the switching part 411 is generated on the main storage device.

[0124] In each of the above embodiments, an example in which the reading device of the present invention is applied to a multifunction device having at least two functions among a copying function, a printer function, a scanner function, and a facsimile function has been described. However, the present invention can be applied to any image forming apparatus such as a copying machine, a printer, a scanner device, and a facsimile device.

[0125] In each of the above embodiments, the image reading device 101 of the image forming apparatus 1 is applied as the reading device, but the present invention is not limited thereto. As the definition of the reading device, it is sufficient that the device can obtain a reading level, such as a line sensor of an equal magnification optical system (contact optical system: CIS method) shown in FIG. 26(a), even if it does not read as an image. The device shown in FIG. 26(a) reads information of a plurality of lines by moving a line sensor or an original.

[0126] Furthermore, as the reading device, it can also be applied to a banknote conveying device shown in FIG. 26(b), a white line detection device of an automated guided vehicle (AGV) shown in FIG. 26(c), and the like.

[0127] The subject of the banknote conveying device shown in FIG. 26(b) is a banknote. The feature amount detected by the banknote conveying device is used for correction processing of the image itself and the like. That is, the banknote conveying device shown in FIG. 26(b) recognizes the inclination of the banknote by edge detection and performs skew correction using the recognized inclination.

[0128] The subject of the white line detection device of the automated guided vehicle shown in FIG. 26(c) is a white line. The feature amount output by the white line detection device of the automated guided vehicle can be used for determining the moving direction of the automated guided vehicle and the like. That is, the white line detection device of the automated guided vehicle recognizes the inclination of the white line area by edge detection and determines the moving direction of the automated guided vehicle using the recognized inclination. Further, in the white line detection device of the automated guided vehicle, it is also possible to perform moving direction correction according to the position and orientation of the automated guided vehicle in a later process. For example, in the case of an automated guided vehicle, it is also possible to execute processing such as stopping the drive when a thickness different from the known thickness of the white line is detected.

[0129] Here, FIG. 27 is a diagram showing another modification example of the reading device. The example shown in FIG. 27 shows an application example to an image reading device 200 used when packaging a load at a production site or the like as the reading device.

[0130] The subjects of the image reading device 200 shown in FIG. 27 are packages A, B, and C of different sizes that are conveyances. As shown in FIG. 27, when packages A, B, and C of different sizes are conveyed by the belt conveyor 201, the feature amounts (edges) of packages A, B, and C are detected by the image reading device 200 of the present invention, whereby the widths of the packages can be detected. Note that when detecting the feature amounts of packages A, B, and C, visible light is effective for black packages, and invisible light is effective for white packages.

[0131] Note that in this case, the background portion 26 may be the surface of the belt conveyor 201, or a dedicated background portion 26 may be arranged with the reading position of the image reading device 200 being the gap of the belt conveyor 201.

[0132] The switching unit 411 of the image reading device 200 switches the use or non-use of each of the mechanical inclination correction unit 70 and the electronic inclination correction unit 80 for the conveyed packages A, B, C, etc. More specifically, when the conveyed packages A, B, and C are of the same size without including multiple types of sizes, the switching unit 411 uses the mechanical inclination correction unit 70, and when the conveyed packages A, B, and C include multiple types of sizes, the switching unit 411 uses the electronic inclination correction unit 80.

[0133] For example, since the user of the device can select the validity / invalidity of mechanical inclination correction by performing a predetermined operation on the operation unit 44, when the conveyed package is a "fragile item", it is possible to prevent damage to small packages that is likely to occur when performing mechanical inclination correction with the mechanical inclination correction unit 70.

[0134] Aspects of the present invention are as follows, for example. <1> An illumination unit that irradiates light onto a subject, An imaging unit that receives the light reflected by the subject and generates an image, A conveyance unit that conveys the subject to a reading position by the imaging unit, A first inclination correction unit that mechanically corrects the inclination of the subject, A second tilt correction unit that electronically corrects the tilt of the image obtained from the imaging unit; A switching unit that switches whether or not to use each of the first tilt correction unit and the second tilt correction unit; Comprising; The switching unit is; When the subject is of only the same size without including a plurality of types of sizes, the first tilt correction unit is used; When the subject includes a plurality of types of sizes, the second tilt correction unit is used. A reading device characterized by the above. <2> When the subject is of only the same size without including a plurality of types of sizes, the switching unit further uses the second tilt correction unit. The reading device according to <1>, characterized by the above. <3> Having an operation unit, When a predetermined operation is performed in the operation unit, the switching unit determines that the subject is composed of a plurality of types of sizes and uses the second tilt correction unit. The reading device according to <1> or <2>, characterized by the above. <4> When an operation of setting the subject of an irregular size is performed in the operation unit, the switching unit uses the second tilt correction unit. The reading device according to <3>, characterized by the above. <5> Provided upstream of the imaging unit in the conveyance direction, comprising a document size detection unit that acquires the size of the subject, Based on the size of the read subject obtained by the document size detection unit and the size of the next subject to be read obtained from the document size detection unit, the switching unit determines that the subject is composed of a plurality of types of sizes. The reading device according to any one of <1> to <4>, characterized by the above. <6> The subject is a transported object. The reading device according to any one of <1> to <5>, characterized by the above. <7> The reading device according to any one of <1> to <6>, and An image forming unit, An image processing apparatus characterized by including the same. <8>A reading method in a reading apparatus including an illumination unit that irradiates light onto a subject, an imaging unit that receives the light reflected by the subject and generates an image, and a conveyance unit that conveys the subject to a reading position by the imaging unit, the method comprising: A first inclination correction step of mechanically correcting the inclination of the subject; A second inclination correction step of electronically correcting the inclination of the image obtained from the imaging unit; A switching step of switching whether to execute each of the first inclination correction step and the second inclination correction step; Including The switching step When the subject is of only the same size without including a plurality of types of sizes, executes the first inclination correction step; When the subject includes a plurality of types of sizes, executes the second inclination correction step. A reading method characterized by the above. <9>A computer that controls a reading apparatus including an illumination unit that irradiates light onto a subject, an imaging unit that receives the light reflected by the subject and generates an image, a conveyance unit that conveys the subject to a reading position by the imaging unit, a first inclination correction unit that mechanically corrects the inclination of the subject, and a second inclination correction unit that electronically corrects the inclination of the image obtained from the imaging unit, Functions as a switching unit that switches whether to use each of the first inclination correction unit and the second inclination correction unit, The switching unit When the subject is of only the same size without including a plurality of types of sizes, uses the first inclination correction unit; When the subject includes a plurality of types of sizes, uses the second inclination correction unit. A program characterized by the above.

Explanation of Signs

[0135] 1 Image processing apparatus 13 Illumination unit 40 Imaging unit 43 Image processing unit 44 Operation unit 52 Original document size detection unit 70 First inclination correction unit 80 Second inclination correction unit 101 Reading device 102 Conveying unit 103 Image forming unit 411 Switching unit

Prior art documents

Patent documents

[0136]

Patent Document 1

Claims

1. An illumination unit that irradiates light onto a subject; An imaging unit that receives the light reflected by the subject and generates an image; A conveyance unit that conveys the subject to a reading position by the imaging unit; A first inclination correction unit that mechanically corrects the inclination of the subject; A second inclination correction unit that electronically corrects the inclination of the image obtained from the imaging unit; A switching unit that switches whether to use each of the first inclination correction unit and the second inclination correction unit; Comprising: The switching unit: When the subject is of only the same size without including multiple types of sizes, uses the first inclination correction unit; When the subject includes multiple types of sizes, uses the second inclination correction unit. A reading device characterized by the above.

2. The switching unit further uses the second inclination correction unit when the subject is of only the same size without including multiple types of sizes. The reading device according to Claim 1, characterized by the above.

3. Having an operation unit, The switching unit, when a predetermined operation is performed on the operation unit, determines that the subject is composed of multiple types of sizes and uses the second inclination correction unit. The reading device according to Claim 1, characterized by the above.

4. The switching unit uses the second inclination correction unit when an operation of setting the subject of an irregular size is performed on the operation unit. The reading device according to Claim 3, characterized by the above.

5. Comprising an original size detection unit provided upstream of the imaging unit in the conveyance direction to acquire the size of the subject, The switching unit determines that the subject is composed of multiple types of sizes based on the size of the read subject obtained by the original size detection unit and the size of the next subject to be read obtained from the original size detection unit. The reading device according to Claim 1, characterized by the above.

6. The subject is a conveyed object. The reading device according to Claim 1, characterized by the above.

7. The reading device according to any one of Claims 1 to 5, And an image forming unit. An image processing device characterized by comprising the above.

8. A reading method in a reading device comprising an illumination unit that irradiates light onto a subject, an imaging unit that receives the light reflected by the subject and generates an image, and a conveyance unit that conveys the subject to a reading position by the imaging unit, A first inclination correction step of mechanically correcting the inclination of the subject; A second inclination correction step of electronically correcting the inclination of the image obtained from the imaging unit; A switching step of switching whether to execute each of the first inclination correction step and the second inclination correction step; comprising; The switching step is as follows: When the subject includes only those of the same size without including a plurality of types of sizes, the first inclination correction step is executed; When the subject includes a plurality of types of sizes, the second inclination correction step is executed. A reading method characterized by this.

9. A computer for controlling a reading device including an illumination unit that irradiates light onto a subject, an imaging unit that receives the light reflected by the subject to generate an image, a transport unit that transports the subject to a reading position by the imaging unit, a first inclination correction unit that mechanically corrects the inclination of the subject, and a second inclination correction unit that electronically corrects the inclination of the image obtained from the imaging unit, functions as a switching unit that switches whether to use each of the first inclination correction unit and the second inclination correction unit, The switching unit is as follows: When the subject includes only those of the same size without including a plurality of types of sizes, the first inclination correction unit is used; When the subject includes a plurality of types of sizes, the second inclination correction unit is used. A program characterized by this.

Images