Image reading device and image processing method

Abstract

To facilitate adjustment of inclination of a cover portion with respect to a body portion in an image reading device.SOLUTION: A first image reading portion 61 is arranged in a main body portion 11. A transport device 4 is arranged on a cover portion 12. A second image reading portion 62 is arranged on the cover section 12. An inclination derivation unit 8d derives two document inclination angles corresponding to the first image reading unit 61 and the second image reading unit 62 by performing image processing on two read images obtained by the first image reading unit 61 and the second image reading unit 62. An information output portion 8a outputs the inclination correction information according to the difference between the two document inclination angles through an information output device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image reading device and an image processing method that facilitate adjustment of the inclination of a cover part relative to a main body part. [Background technology]

[0002] The image reading device may include a document transport device and an image reading unit that reads an image from a document transported by the document transport device. In general, the image reading unit is disposed in a main body. The document transport device is incorporated in a cover that can open and close the top surface of the main body.

[0003] There are cases where the cover is attached to the main body in a state where it is tilted from the original orientation, in which case the image read by the image reading unit in the main body is distorted from the original image.

[0004] It is therefore important that the cover portion is attached to the main body portion in the correct orientation.

[0005] For example, it is known that the image reading unit of the main body performs an image reading process on a portion of the cover unit on which a specific mark is written, and further, a recognition unit recognizes the deviation between the position of the mark detected from the read image and a target position (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2007-306411 A Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, when an image of a mark written on a part of the cover part is read by the image reading part of the main body part, it is possible to derive the inclination of the cover part relative to the main body part based on the deviation between the position of the mark in the read image and the target position.

[0008] However, if the calibration member on which the mark is written is not attached in the correct position and in the correct orientation with respect to the cover portion, the inclination of the cover portion cannot be derived accurately.

[0009] In addition, it is difficult to determine whether the calibration member is attached to the cover portion in the correct position and in the correct orientation.

[0010] An object of the present invention is to provide an image reading device and an image processing method that facilitates adjustment of the inclination of a cover part relative to a main body part in which an image reading part is arranged when a cover part incorporating a document transport device is attached to the main body part in which an image reading part is arranged. [Means for solving the problem]

[0011] An image reading device according to one aspect of the present invention includes a main body, a first image reading unit, a cover, a transport device, a second image reading unit, an inclination deriving unit, and an information output unit. The first image reading unit is disposed in the main body and reads an image from a document passing through a reading position on an upper surface of the main body. The cover is connected to the main body and supported so as to be capable of opening and closing the upper surface of the main body. The transport device is disposed in the cover and transports the document along a transport path passing through the reading position. The second image reading unit is disposed in the cover and reads an image from the document transported along the transport path. The inclination deriving unit executes an inclination derivation process for deriving two document inclination angles corresponding to the first image reading unit and the second image reading unit by image processing on two read images obtained by the first image reading unit and the second image reading unit, respectively. The information output section outputs skew correction information corresponding to the difference between the two document skew angles through an information output device.

[0012] An image processing method according to another aspect of the present invention is a method for processing a read image obtained by an image reading device including the main body, the first image reading unit, the cover, the transport device, and the second image reading unit. The image processing method includes executing a tilt derivation process for deriving two document tilt angles corresponding to the first image reading unit and the second image reading unit by image processing of two read images obtained by the first image reading unit and the second image reading unit. The image processing method further includes outputting tilt correction information according to a difference between the two document tilt angles through an information output device. Effect of the Invention

[0013] According to the present invention, it is possible to provide an image reading device and an image processing method that facilitates adjustment of the inclination of the cover part relative to a main body part in which an image reading part is arranged when a cover part incorporating a document transport device is attached to the main body part in which an image reading part is arranged. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing the configuration of an image reading device according to an embodiment. [Diagram 2] FIG. 2 is a block diagram showing the configuration of a control device in the image reading device according to the embodiment. [Diagram 3] FIG. 3 is a configuration diagram of a cover connecting mechanism in the image reading device according to the embodiment. [Figure 4] FIG. 4 is a flowchart showing an example of a procedure for adjustment support processing in the image forming apparatus according to the embodiment. [Diagram 5] FIG. 5 is a diagram showing an example of the upper side of a document detected from a read image. [Figure 6] FIG. 6 is a diagram showing an example of a side edge portion of a document detected from a read image. [Figure 7] FIG. 7 is a diagram showing an example of a line image of a proofread document detected from a read image. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the following embodiment is an example of the present invention, and is not intended to limit the technical scope of the present invention.

[0016] [Configuration of image reading device 1] The image reading device 1 according to the embodiment is a device capable of conveying an original 9 and reading an image of the original 9 being conveyed.

[0017] 1, the image reading device 1 includes a main body 11 and a cover 12 that covers the upper surface of the main body 11. The main body 11 is a housing that houses various devices.

[0018] The cover part 12 is connected to the main body part 11 and supported so as to be displaceable between a closed position where the cover part 12 covers the upper surface of the main body part 11 and an open position where the cover part 12 opens the upper surface of the main body part 11. In other words, the cover part 12 is supported so as to be able to open and close the upper surface of the main body part 11.

[0019] Furthermore, the image reading device 1 includes a contact glass 64 and a platen glass 65 that are disposed on the upper surface of the cover unit 12. The contact glass 64 and the platen glass 65 are each a transparent plate-like member.

[0020] The image reading device 1 further includes a document transport device 2, an image reading unit 6, a moving mechanism 7, a control device 8, an operation device 801, and a display device 802. The document transport device 2 is incorporated in a cover unit 12.

[0021] The document transport device 2 includes a supply tray 3a, a discharge tray 3b, a transport path 40, a transport device 4, a supplied document sensor 5a, and a transported document sensor 5b, etc. The supply tray 3a and the discharge tray 3b are each capable of holding documents 9 thereon.

[0022] The transport path 40 forms a passage through which the document 9 is transported within the cover portion 12. The transport path 40 extends from an entrance corresponding to the supply tray 3a, through a reading position P1 on the contact glass 64, and to an exit corresponding to the discharge tray 3b.

[0023] The supplied document sensor 5a detects the document 9 placed on the supply tray 3a. For example, the supplied document sensor 5a includes a first displacement member and a first detection sensor, neither of which is shown.

[0024] The first displacement member is displaced from an upper position, which is an initial position, to a lower position under the load of the document 9 on the supply tray 3a. The first detection sensor detects the first displacement member displaced to the lower position.

[0025] The conveyed document sensor 5b detects the document 9 sent from the supply tray 3a to the conveying path 40. For example, the conveyed document sensor 5b includes a second displacement member and a second detection sensor, neither of which is shown.

[0026] The second displacement member is displaced from the reference position to the retracted position by coming into contact with the document 9 sent from the supply tray 3a to the transport path 40. The detection sensor detects the second displacement member displaced to the retracted position.

[0027] The transport device 4 is disposed in the cover portion 12. The transport device 4 sends out the originals 9 on the supply tray 3a one by one to the transport path 40, further transports the originals 9 along the transport path 40, and further discharges the originals 9 onto the discharge tray 3b.

[0028] The transport device 4 includes a delivery mechanism 41 corresponding to the supply tray 3a, and a plurality of transport roller pairs 43 arranged along the transport path .

[0029] The sending mechanism 41 sends out the documents 9 on the supply tray 3a one by one to the transport path 40. In this embodiment, the sending mechanism 41 sends out the uppermost document 9 on the supply tray 3a to the transport path 40.

[0030] The plurality of transport roller pairs 43 are rotated by a motor (not shown), so that the plurality of transport roller pairs 43 transport the original 9 along the transport path 40, and further discharge the original 9 from the transport path 40 to the discharge tray 3b.

[0031] The image reading unit 6 executes an image reading process to read an image formed on the document 9 and output data of the read image. The image reading unit 6 is capable of executing the image reading process on the document 9 transported along the transport path 40. Furthermore, the image reading unit 6 is also capable of executing the image reading process on the document 9 placed on the platen glass 65. In the following description, the image read from the document 9 by the image reading unit 6 is referred to as a read image g1 (see FIGS. 5 to 7).

[0032] In this embodiment, the image reading unit 6 includes a first image reading unit 61, a second image reading unit 62, and an AFE (Analog Front End) 60.

[0033] In the following description, the upper surface of the document 9 placed on the supply tray 3a is referred to as a first surface, and the lower surface of the document 9 placed on the supply tray 3a is referred to as a second surface.

[0034] The first image reading unit 61 is disposed inside the main body 11. The first image reading unit 61 reads an image of the first surface of the document 9 passing through the reading position P1 of the conveying path 40 while being held at a position facing the reading position P1.

[0035] The second image reading unit 62 is disposed within the cover unit 12. The second image reading unit 62 reads an image of the second surface of the original 9 transported along the transport path 40. The second image reading unit 62 reads an image of the original 9 at a position upstream of the reading position P1 on the transport path 40 in the original transport direction.

[0036] In this embodiment, each of the first image reading unit 61 and the second image reading unit 62 includes a light emitting unit 6a, a lens 6b, and an image sensor 6c (see FIG. 1). The light emitting unit 6a, the lens 6b, and the image sensor 6c are each formed to extend along the main scanning direction.

[0037] The light emitting unit 6a irradiates light onto the original 9. The lens 6b guides the light reflected by the original 9 to the image sensor 6c. The image sensor 6c is a line sensor that detects the intensity of the light reflected by the original 9 and outputs a detection signal as a signal of the read image g1.

[0038] The AFE 60 converts the signal of the scanned image g1 into digital image data and outputs the image data. The digital image data is the data of the scanned image g1.

[0039] In the example shown in FIG. 1, each of the first image reading unit 61 and the second image reading unit 62 is a CIS (Contact Image Sensor) in which a light emitting unit 6a, a lens 6b, and a CMOS (Complementary Metal Oxide Semiconductor) type image sensor 6c are integrated.

[0040] The moving mechanism 7 moves the first image reading unit 61 in a range from a position facing the contact glass 64 to a position facing the platen glass 65 .

[0041] When the document 9 is transported by the transport device 4, the moving mechanism 7 holds the first image reading unit 61 at a position facing the contact glass 64.

[0042] On the other hand, when the original 9 is placed on the platen glass 65, the movement mechanism 7 moves the first image reading unit 61 along the platen glass 65. As a result, the image sensor 6c of the first image reading unit 61 reads the image of the original 9 while the light of the light emitting unit 6a of the first image reading unit 61 scans the original 9 on the platen glass 65.

[0043] That is, when the conveying device 4 is operating, the image reading unit 6 executes the image reading process on the document 9 conveyed along the conveying path 40. On the other hand, when the conveying device 4 is not operating, the image reading unit 6 executes the image reading process on the document 9 placed on the platen glass 65.

[0044] The image sensor 6c of the first image reading unit 61 may be a CCD (Charge Coupled Device) type sensor. In this case, the moving mechanism 7 moves the light emitting unit 6a and the lens 6b, and the CCD type image sensor 6c is fixed at a predetermined position.

[0045] The operation device 801 is a device that accepts operations by a person, and includes, for example, an operation button and a touch panel. The display device 802 is a device that displays information, and includes, for example, a panel display device such as a liquid crystal display unit.

[0046] The control device 8 executes various data processing and control of the image reading device 1. As shown in Fig. 3, the control device 8 includes a CPU (Central Processing Unit) 81, and peripheral devices such as a RAM (Random Access Memory) 82, a secondary storage device 83, and a signal interface 84. The control device 8 also includes a communication device 85 capable of communicating with other devices.

[0047] The secondary storage device 83 is a computer-readable non-volatile storage device. The secondary storage device 83 can store and update the computer programs and various data. For example, one or both of a flash memory and a hard disk drive are adopted as the secondary storage device 83.

[0048] The signal interface 84 converts signals output by various sensors into digital data, and transmits the converted digital data to the CPU 81. Furthermore, the signal interface 84 converts control commands output by the CPU 81 into control signals, and transmits the control signals to the devices to be controlled.

[0049] The CPU 81 is a processor that executes various types of data processing and control by executing computer programs. The RAM 82 is a computer-readable volatile storage device. The RAM 82 temporarily stores the computer programs executed by the CPU 81 and data that is output and referenced in the course of the CPU 81 executing various types of processing.

[0050] The CPU 81 includes a plurality of processing modules that are realized by executing the computer programs, including a main control unit 8a, a transport control unit 8b, a reading control unit 8c, and an image processing unit 8d.

[0051] The main control unit 8a executes control to start various processes in response to an operation on the operation device 801, and control of the display device 802. The transport control unit 8b controls the transport device 4 to control the transport of the document 9.

[0052] The reading control unit 8c controls the image reading unit 6 to execute the image reading process. The image processing unit 8d executes various image processes on the read image g1 obtained by the image reading process.

[0053] There is a case where the cover unit 12 is attached to the main body unit 11 in a state where it is tilted from the original orientation. In this case, the read image g1 obtained by the first image reading unit 61 in the main body unit 11 is in a state where the original image is distorted.

[0054] Therefore, it is important that the cover portion 12 is attached to the main body portion 11 in the correct orientation.

[0055] 3, the cover portion 12 is connected to the main body portion 11 by cover connecting mechanisms 13, 14 so as to be rotatable up and down. The cover connecting mechanisms 13, 14 include a first connecting portion 13 and a second connecting portion 14.

[0056] The first connecting portion 13 includes a first base member 131 fixed to the main body portion 11, and a first hinge member 132 connected to the first base member 131. For example, the first base member 131 is fixed to the main body portion 11 by screws or the like.

[0057] One of a pair of plate portions constituting the first hinge member 132 is connected to the first base member 131, and the other is connected to the cover portion 12. For example, the first hinge member 132 is connected to the cover portion 12 by fastening with screws or the like.

[0058] The first connecting portion 13 further includes a rotary connecting mechanism 133. The rotary connecting mechanism 133 rotatably connects the first hinge member 132 to the first base member 131 along the upper surface of the main body portion 11. The first hinge member 132 is rotatable with respect to the first base member 131 about a connecting shaft 133a.

[0059] Therefore, the first connecting portion 13 connects the cover portion 12 to the main body portion 11 so as to be vertically rotatable and rotatable along the upper surface of the main body portion 11 around the connecting shaft 133a.

[0060] For example, the connecting shaft 133a is disposed on an extension line of the contact glass 64 in the longitudinal direction with respect to the reading position P1.

[0061] The second connecting portion 14 includes a second base member 141 fixed to the main body portion 11, and a second hinge member 142 connected to the second base member 141. For example, the second base member 141 is fixed to the main body portion 11 by screw fastening or the like.

[0062] One of a pair of plate portions constituting the second hinge member 142 is connected to the second base member 141, and the other is connected to the cover portion 12. For example, the second hinge member 142 is connected to the cover portion 12 by fastening with screws or the like.

[0063] The second connecting portion 14 further includes a movable connecting mechanism 143. The movable connecting mechanism 143 connects the second hinge member 142 to the second base member 141 so as to be displaceable along an arc.

[0064] The second hinge member 142 is displaceable along an arc centered on the connecting shaft 133a, and is fixed to the second base member 141 by a fastener 144 such as a screw.

[0065] Fixing device 144 is loosened and the position of second hinge member 142 relative to second base member 141 is adjusted, thereby adjusting the angle of cover portion 12 relative to main body portion 11. The adjusted angle of cover portion 12 is an angle about connecting shaft 133a as the center of rotation.

[0066] In this embodiment, the rotary connection mechanism 133 and the movable connection mechanism 143 are an example of an inclination adjustment mechanism in the cover connection mechanisms 13 and 14 that connect the main body part 11 and the cover part 12.

[0067] The second base member 141 has a plurality of scales 145 that indicate the position of the second hinge member 142 relative to the second base member 141. Each of the plurality of scales 145 represents an adjustment amount in the tilt adjustment mechanism. The plurality of scales 145 quantify the adjustment amount in the tilt adjustment mechanism.

[0068] Incidentally, when an image of a mark written on a part of the cover part 12 is read by the first image reading unit 61 of the main body part 11, it is possible to derive the inclination of the cover part 12 relative to the main body part 11 based on the deviation between the position of the mark in the read image g1 and the target position.

[0069] However, if a calibration member such as a plate having the marks thereon is not attached to the cover portion 12 in the correct position and in the correct orientation, the inclination of the cover portion 12 cannot be derived accurately.

[0070] In addition, it is difficult to determine whether the calibration member is attached to the cover portion 12 in the correct position and in the correct orientation.

[0071] In the image reading device 1, the CPU 81 executes an adjustment support process, which will be described later (see FIG. 4). The adjustment support process is a process for facilitating adjustment of the inclination of the cover part 12 with respect to the main body part 11 when the cover part 12 is attached to the main body part 11.

[0072] When the main control unit 8a detects a predetermined adjustment start operation on the operation device 801, it starts the adjustment support process.

[0073] [Adjustment support processing] An example of the procedure of the adjustment support process will be described below with reference to the flowchart shown in Fig. 4. The adjustment support process is an embodiment of an image processing method for processing the read image g1 obtained by the image reading device 1.

[0074] In the following description, S1, S2, ... represent identification symbols of a plurality of steps in the adjustment support process. In the adjustment support process, first, the process of step S1 is executed.

[0075] <Process S1> In step S1, the main control unit 8a executes a document preparation guide process for displaying predetermined guide information on the display device 802. After that, the main control unit 8a shifts the process to step S2.

[0076] The guidance information is information that guides the user to place a predetermined document 9 on the supply tray 3a. For example, the guidance information is information that guides the user to place an arbitrary document 9 of a predetermined size on the supply tray 3a.

[0077] The guidance information may be information for guiding the user to place a predetermined proofreading manuscript 9A on the supply tray 3a (see FIG. 7). The proofreading manuscript 9A is a manuscript 9 on both sides of which a predetermined line image is formed.

[0078] For example, on both sides of the proofreading manuscript 9A, one of a horizontal line image g13 extending in the horizontal direction of the proofreading manuscript 9A and a vertical line image g14 extending in the vertical direction of the proofreading manuscript 9A is formed.

[0079] <Process S2> In step S2, when the main control unit 8a detects a reading start operation on the operating device 801 while the document 9 on the supply tray 3a is being detected by the supplied document sensor 5a, the main control unit 8a shifts the process to step S3.

[0080] The main control section 8a waits until it detects the reading start operation in a state where the document 9 on the supply tray 3a is detected by the supplied document sensor 5a.

[0081] <Process S3> In step S3, the transport control unit 8b causes the transport device 4 to start transporting the document 9, and then causes the process to proceed to step S4.

[0082] <Process S4> In step S4, the reading control unit 8c executes the image reading process by the image reading unit 6. After that, the reading control unit 8c shifts the process to step S5.

[0083] By the process of step S4, the image reading process of the second side of the document 9 by the second image reading unit 62 and the image reading process of the first side of the document 9 by the first image reading unit 61 are executed. As a result, two read images g1 corresponding to both sides of the document 9 are obtained.

[0084] <Process S5> In step S5, the image processing unit 8d executes a tilt derivation process. After that, the image processing unit 8d shifts the process to step S6. The image processing unit 8d that executes the process of step S5 is an example of a tilt derivation unit.

[0085] The inclination derivation process is a process for deriving two document inclination angles θ1 corresponding to the first image reading unit 61 and the second image reading unit 62 by image processing on each of the two read images g1 obtained in step S4 (see FIGS. 5 and 6).

[0086] For example, in step S5, the image processor 8d detects edges, such as the top edge g11 or the side edge g12, of the rectangular document 9 from the read image g1 (see FIGS. 5 and 6).

[0087] Specifically, the image processor 8d can detect the top side g11 of the document 9 by performing a known edge detection process on the read image g1 along the vertical direction D2. Also, the image processor 8d can detect the side side g12 of the document 9 by performing the edge detection process on the read image g1 along the horizontal direction D1.

[0088] Furthermore, the image processor 8d derives the inclination angle of the side portion with respect to a predetermined reference direction as the document inclination angle θ1 (see FIGS. 5 and 6).

[0089] Furthermore, when the read image g1 is an image read from the proofreading manuscript 9A, the image processing section 8d can detect the horizontal line image g13 or the vertical line image g14 by the edge detection process.

[0090] In addition, when the horizontal line image g13 or the vertical line image g14 is an image of a predetermined color such as red, green or blue, the image processing unit 8d can detect the horizontal line image g13 or the vertical line image g14 by detecting an image of a specific color from the read image g1 (see FIG. 7).

[0091] Moreover, the image processor 8d can derive the inclination angle of the horizontal line image g13 or the vertical line image g14 with respect to a predetermined reference direction as the document inclination angle θ1 (see FIG. 7).

[0092] Usually, the orientation of the original 9 hardly changes while the original 9 is being transported from the position of the second image reading unit 62 to the reading position P1.

[0093] Therefore, the difference between the two document inclination angles θ1 derived in step S5 represents the angle between the longitudinal direction of the first image reading unit 61 and the longitudinal direction of the second image reading unit 62. In addition, the angle between the longitudinal direction of the first image reading unit 61 and the longitudinal direction of the second image reading unit 62 represents the inclination of the cover unit 12 with respect to the main body unit 11.

[0094] 5 to 7 show examples in which the document inclination angle θ1 is not 0° for the sake of convenience. However, when the inclination adjustment of the cover unit 12 is performed, the document inclination angle θ1 corresponding to the read image g1 obtained by at least the second image reading unit 62 is usually approximately 0°.

[0095] The image processing unit 8d may shift the process to step S1 when the document inclination angle θ1 derived from the read image g1 obtained by the second image reading unit 62 is outside a predetermined allowable range. As a result, the processes of steps S1 to S4 are repeated until the document 9 is transported in the correct orientation without being skewed.

[0096] Furthermore, when the processes of steps S1 to S4 have been repeated a predetermined number of times, the main control unit 8a may display cover inside adjustment information on the display device 802. The cover inside adjustment information is information that prompts the adjuster to adjust the attachment state of the document transport device 2 and the second image reading unit 62 relative to the cover unit 12.

[0097] <Process S6> In step S6, the main control unit 8a outputs inclination correction information corresponding to the difference between the two document inclination angles θ1 derived in step S5 through the display device 802. Thereafter, the main control unit 8a ends the adjustment support process.

[0098] The main control unit 8a that executes the process of step S6 is an example of an information output unit. The display device 802 is an example of an information output device. The main control unit 8a may output the tilt correction information as sound through an audio output device (not shown). The audio output device is an example of an information output device.

[0099] For example, the skew correction information is information obtained by converting the difference between the two document skew angles θ1 into an adjustment amount of the scale 145 in the movable connecting mechanism 143. The adjustment amount of the scale 145 is one example of an adjustment amount in the skew adjustment mechanism.

[0100] According to the present embodiment, it is possible to easily adjust the inclination of the cover part 12 with respect to the main body part 11. In addition, it is not necessary to attach a calibration member having a mark to be read by the first image reading unit 61 to the cover part 12.

[0101] [Application example] 4 may be executed by a processor of an information processing device capable of communicating with the image reading device 1. In this case, the CPU 81 transmits data of the two read images g1 obtained in step S4 to the information processing device through the communication device 85.

[0102] Meanwhile, the processor of the information processing device receives data of the two read images g1 from the image reading device 1, and further executes the processes of steps S5 and S6. When this application example is adopted, the same effects as when the above-described embodiment is adopted can be obtained. [Explanation of symbols]

[0103] 1: Image reader 2: Document feeder 3a: Supply tray 3b: Output tray 4: Transport device 6: Image reading section 6a: Light emitting part 6b: Lens 6c: Image sensor 8: Control device 11: Main body 12: Cover part 13: First connecting part (cover connecting mechanism) 14: Second connection part (cover connection mechanism) 40: Transport path 61: First image reading unit 62: Second image reading unit 64: Contact glass 801: Operating device 802:Display device

Claims

1. A main body portion, a first image reading unit disposed in the main body and configured to read an image from a document passing through a reading position on an upper surface of the main body; a cover portion connected to the main body portion and supported so as to be capable of opening and closing an upper surface of the main body portion; a conveying device disposed in the cover section and configured to convey the document along a conveying path passing through the reading position; a second image reading unit disposed on the cover unit and configured to read an image from a document conveyed along the conveyance path; a tilt derivation unit that executes a tilt derivation process for deriving two document tilt angles corresponding to the first image reading unit and the second image reading unit by image processing on two read images obtained by the first image reading unit and the second image reading unit, respectively; an information output unit that outputs skew correction information corresponding to the difference between the two document skew angles through an information output device; the tilt correction information includes information obtained by converting a difference between the two document tilt angles into an adjustment amount of a tilt adjustment mechanism in a cover connection mechanism that connects the main body and the cover.

2. The slope derivation process includes: Detecting sides of the rectangular document from the read image; The image reading apparatus according to claim 1 , further comprising: deriving an inclination angle of the side portion with respect to a predetermined reference direction as the document inclination angle.

3. The slope derivation process includes: Detecting a predetermined line image included in the read image; 3. The image reading apparatus according to claim 1, further comprising: deriving an inclination angle of the line image with respect to a predetermined reference direction as the document inclination angle.

4. A main body portion, a first image reading unit disposed in the main body and configured to read an image from a document passing through a reading position on an upper surface of the main body; a cover portion connected to the main body portion and supported so as to be capable of opening and closing an upper surface of the main body portion; a conveying device disposed in the cover section and configured to convey the document along a conveying path passing through the reading position; a second image reading unit that is disposed in the cover unit and that reads an image from a document transported along the transport path; executing an inclination derivation process for deriving two document inclination angles corresponding to the first image reading unit and the second image reading unit by image processing on each of two read images obtained by the first image reading unit and the second image reading unit; outputting skew correction information corresponding to the difference between the two document skew angles through an information output device; The image processing method, wherein the skew correction information includes information obtained by converting a difference between the two document skew angles into an adjustment amount of a skew adjustment mechanism in a cover connection mechanism that connects the main body portion and the cover portion.

Images