Image reading apparatus, method for controlling image reading apparatus, and storage medium

Abstract

To provide an image reading apparatus, a control method of the image reading apparatus, and a program capable of improving execution accuracy for stopping conveyance of a document.SOLUTION: An image reading apparatus includes a conveyance unit configured to convey a document in a conveyance direction, a reading unit configured to read an image from the document conveyed by the conveyance unit, and a control unit configured to control the conveyance unit and the reading unit. The control unit acquires, from the image read by the reading unit, a first end position and a second end position that are between a first reference position and a second reference position included in the first end side and that are included in the first end side, and in a case where, in the transport direction, both the first end position and the second end position are on the side opposite to the transport direction with respect to a first straight line passing through the first reference position and the second reference position, the control unit stops the transport of the document when an inclination angle of a second straight line passing through the first end position and the second end position with respect to the width direction exceeds a specified angle.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an image reading device, a control method for an image reading device, and a program. [Background technology]

[0002] For example, Patent Document 1 discloses an image reading device that is an example of a reading device that reads an image of a document. When the tilt angle of the document being conveyed is greater than a specified angle, the image reading device determines that the document has skewed, and performs control to stop the conveyance of the document. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-75600 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in such an image reading device, the accuracy of calculating the inclination angle of the document being conveyed decreases depending on the shape of the document, which may result in a decrease in the accuracy of stopping the conveyance of the document. [Means for solving the problem]

[0005] An image reading device that solves the above problem includes a conveying unit that conveys a document in a conveying direction, a reading unit that reads an image from the document conveyed by the conveying unit, and a control unit that controls the conveying unit and the reading unit, and when a direction intersecting the conveying direction is defined as a width direction, the control unit performs a first edge position acquisition process that acquires, from the image read by the reading unit, a first edge position that is between a first reference position and a second reference position that is included in a first edge of a document area that is on the conveying direction side of the document area, and a second end position acquisition process for acquiring a second end position that is between the first reference position and the second reference position, is included in the first end side, and is different from the first end position from the acquired image; and a transport stop process for stopping transport of the document when an inclination angle of the second line that passes through the first end position and the second end position with respect to the width direction exceeds a specified angle, in a case where both the first end position and the second end position are on the opposite side of the transport direction from a first line that passes through the first reference position and the second reference position.

[0006] A control method for an image reading device that solves the above problem performs the following steps: when a direction intersecting the transport direction in which the document is transported is defined as the width direction, obtain from an image read from the document a first end position that is between a first reference position and a second reference position that is included in a first end edge of multiple end edges of the document area that is closer to the transport direction, and that is included in the first end edge; obtain from the image read from the document a second end position that is between the first reference position and the second reference position, that is included in the first end edge, and that is different from the first end position; and when both the first end position and the second end position are on the opposite side of the transport direction from a first straight line that passes through the first reference position and the second reference position, stopping the transport of the document when the inclination angle of the second straight line that passes through the first end position and the second end position with respect to the width direction exceeds a specified angle.

[0007] The program for solving the above problem executes the following operations on one or more computers, when a direction intersecting the transport direction in which the document is transported is defined as the width direction: acquiring, from an image read from the document, a first end position that is between a first reference position and a second reference position that is included in a first end edge of multiple end edges of the document area that is closer to the transport direction, and that is included in the first end edge; acquiring, from the image read from the document, a second end position that is between the first reference position and the second reference position, that is included in the first end edge, and that is different from the first end position; and, when both the first end position and the second end position are on the opposite side of the transport direction from a first straight line that passes through the first reference position and the second reference position, stopping the transport of the document when the inclination angle of the second straight line that passes through the first end position and the second end position with respect to the width direction exceeds a specified angle. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an image reading device according to the first and second embodiments. [Figure 2] FIG. 2 is a schematic diagram showing an image area in the first and second embodiments. [Figure 3] FIG. 3 is a schematic diagram showing an image area in the first and second embodiments. [Figure 4] FIG. 4 is a flowchart showing the document transport monitoring process of the first embodiment. [Figure 5] FIG. 5 is a flowchart showing the document transport monitoring process according to the first and second embodiments. [Figure 6] FIG. 6 is a flowchart showing the document transport monitoring process of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [First embodiment] An embodiment of an image reading device, a control method for an image reading device, and a program therefor will be described below with reference to the drawings. The image reading device is, for example, a sheet-fed scanner in which a fixed reading unit reads a document such as paper or film being conveyed. Hereinafter, the direction in which the document is conveyed will be referred to as the conveying direction D1. The direction intersecting with the conveying direction D1 will be referred to as the scanning direction D2.

[0010] <Configuration of image reading device 11> 1, the image reading device 11 may include a housing 12 and a support unit 13. The support unit 13 supports the housing 12. The support unit 13 is attached to the housing 12. The support unit 13 is installed on, for example, a horizontal surface.

[0011] The housing 12 has a supply port 14 and a discharge port 15. The supply port 14 is an opening through which the original M is supplied. The original M is supplied into the housing 12 through the supply port 14. The discharge port 15 is an opening through which the original M is discharged. The original M is discharged from inside the housing 12 through the discharge port 15.

[0012] The image reading device 11 may include a transport path 16. The transport path 16 is a path along which the original M is transported. The transport path 16 extends within the housing 12. The transport path 16 extends from the supply port 14 toward the discharge port 15. The transport path 16 extends along a transport direction D1.

[0013] The image reading device 11 may include a discharge tray 17. The discharge tray 17 is attached to the housing 12. The discharge tray 17 receives the document M after reading. The discharge tray 17 receives the document M discharged from the discharge port 15.

[0014] The image reading device 11 includes a placement unit 19, a first document detection unit 20, a feeding unit 21, and a reading unit 22. The placing section 19 is attached to the housing 12. A plurality of original documents M can be placed on the placing section 19. "Placing" means placing something in a stacked manner. The original documents M before being read are set on the placing section 19. The original documents M are set on the placing section 19 with their leading edges entering the supply port 14. When the original documents M are set on the placing section 19, the leading edges of the original documents M abut against the feeding section 21.

[0015] The first document detection unit 20 detects the document M placed on the placement unit 19. The first document detection unit 20 may be, for example, a contact sensor equipped with a lever, or a non-contact sensor such as an optical sensor.

[0016] The feeding section 21 includes a feeding roller 24 and a separating section 25. The feeding section 21 sends out the documents M placed on the placing section 19 to the transport path 16 one by one in order. The feed roller 24 feeds the document M from the placement unit 19. The feed roller 24 is driven to rotate. The axial direction of the feed roller 24 is aligned with the scanning direction D2. The feed roller 24 may be provided at a position above the separation unit 25. The feed roller 24 may come into contact with the surface of the document M.

[0017] The separating unit 25 separates the original documents M fed by the feeding roller 24. In this embodiment, the separating unit 25 is a roller for separating the original documents M one by one. The axial direction of the separating unit 25 is aligned with the scanning direction D2. The separating unit 25 may come into contact with the back surface of the original documents M.

[0018] The separating unit 25 is configured, for example, by rollers having a higher coefficient of friction with respect to the original documents M than with each other. A rotational load is applied to the separating unit 25 by, for example, a torque limiter. Therefore, when multiple original documents M are sandwiched between the feed roller 24 and the separating unit 25, the separating unit 25 is less likely to rotate in response to the driving rotation of the feed roller 24. In other words, the feed roller 24 and the separating unit 25 separate the original documents M one by one. This reduces the risk of two overlapping original documents M being transported.

[0019] The image reading device 11 may include a transport unit 26. The transport unit 26 is configured to transport the original M along the transport direction D1. The transport unit 26 transports the original M along the transport path 16. The transport unit 26 includes, for example, one or more rollers. The transport unit 26 includes, for example, a first roller pair 27 and a second roller pair 28.

[0020] The first roller pair 27 and the second roller pair 28 are provided downstream of the feeding unit 21 in the conveying direction D1. The first roller pair 27 and the second roller pair 28 are aligned, for example, along the conveying path 16. In this embodiment, the feeding unit 21, the first roller pair 27, and the second roller pair 28 are aligned in this order in the conveying direction D1. The first roller pair 27 and the second roller pair 28 each convey the document M by rotating while sandwiching the document M therebetween. The axial directions of the first roller pair 27 and the second roller pair 28 are aligned along the scanning direction D2.

[0021] The first roller pair 27 is located upstream of the reading unit 22 in the conveying direction D1. The second roller pair 28 is located downstream of the reading unit 22 in the conveying direction D1. The first roller pair 27 and the second roller pair 28 are located so as to sandwich the reading unit 22 in the conveying direction D1.

[0022] The image reading device 11 may include a rotation detection unit 29 that detects the rotation of the first roller pair 27. The rotation detection unit 29 is, for example, a rotary encoder. The rotation detection unit 29 may output the amount of rotation of the first roller pair 27 by detecting the scale of an encoder that rotates together with the first roller pair 27.

[0023] The image reading device 11 may include a second document detection unit 30. The image reading device 11 may include a plurality of second document detection units 30 arranged side by side in the scanning direction D2. The second document detection unit 30 may be a sensor that detects the document M. The second document detection unit 30 detects the leading edge of the document M. The second document detection unit 30 is, for example, an optical sensor. The second document detection unit 30 is, for example, provided between the first roller pair 27 and the reading unit 22 in the transport direction D1.

[0024] The image reading device 11 may include one or more reading units 22. The reading units 22 are configured to read an image from an original document M. The reading units 22 read an image from an original document M being transported in a transport direction D1. The reading units 22 are housed in a housing 12.

[0025] The image reading device 11 of this embodiment includes two reading units 22. The two reading units 22 are positioned on either side of the transport path 16. The two reading units 22 are positioned on the transport path 16 between a first roller pair 27 and a second roller pair 28. The two reading units 22 face each other. The reading units 22 are elongated in the scanning direction D2. When the scanning direction D2 is referred to as the main scanning direction, the transport direction D1 can also be said to be the sub-scanning direction.

[0026] The two reading units 22 read different sides of the document M. Of the two reading units 22, one reading unit 22 reads the front side of the document M. Of the two reading units 22, the other reading unit 22 reads the back side of the document M. In this way, the image reading device 11 reads one side of the document M or both sides of the document M.

[0027] The reading unit 22 includes, for example, a light source 31, a plurality of image sensors 32, and a background plate 33. The light source 31 is, for example, an LED or a fluorescent lamp. The light source 31 emits light toward the opposing reading unit 22. The light source 31 is, for example, elongated in the scanning direction D2.

[0028] The multiple image sensors 32 are arranged in the scanning direction D2. The multiple image sensors 32 are modularized. The image sensors 32 are, for example, contact-type image sensors. More specifically, the image sensors 32 are CMOS image sensors. The image sensors 32 photoelectrically convert the received light. The image sensors 32 output an output value according to the amount of received light.

[0029] The image sensor 32 may be a monochrome sensor or a color sensor. The reading unit 22 may be configured to read the original M in full color. For example, the reading unit 22 may be configured to read the original M in three colors, RGB. The reading unit 22 may be configured to read the original M in grayscale.

[0030] The background plate 33 faces, for example, an image sensor 32 and a light source 31 provided in another reading unit 22. Light is irradiated onto the background plate 33 from the light source 31 provided in the opposing reading unit 22. The background plate 33 reflects the irradiated light. The light reflected by the background plate 33 is incident on the image sensor 32 provided in the reading unit 22 facing the background plate 33. The background plate 33 is read by the image sensor 32 as a background together with the original M.

[0031] The background plate 33 preferably has a color that allows the document M and the background plate 33 to be distinguished from each other when the image sensor 32 reads the document M and the background plate 33 together. The background plate 33 is, for example, gray.

[0032] The image reading device 11 may include an operation unit 40. The operation unit 40 is attached to the housing 12, for example. The operation unit 40 accepts operations from a user. The image reading device 11 may include a display unit 41. The display unit 41 displays an image related to the image reading. The operation unit 40 is, for example, a touch panel integrated with the display unit 41, but may also be, for example, a button, a switch, etc.

[0033] The image reading device 11 may be configured to receive operations from, for example, a terminal communicably connected to the image reading device 11. The terminal is, for example, a personal computer or a smartphone owned by the user.

[0034] The image reading device 11 includes a control unit 42. The control unit 42 comprehensively controls the driving of each mechanism in the image reading device 11, and controls various operations executed by the image reading device 11. The control unit 42 may be configured as a circuit including: α: one or more processors that execute various processes according to a computer program; β: one or more dedicated hardware circuits that execute at least some of the various processes; or γ: a combination thereof. The hardware circuit is, for example, an application-specific integrated circuit. The processor includes a CPU and memory such as RAM and ROM, and the memory stores program code or instructions configured to cause the CPU to execute processes. The memory, i.e., computer-readable medium, includes any readable medium that can be accessed by a general-purpose or dedicated computer.

[0035] The control unit 42 controls the reading unit 22 and the transport unit 26. The control unit 42 controls the feeding unit 21. The control unit 42 receives detection signals from the first document detection unit 20 and the second document detection unit 30.

[0036] The control unit 42 may include a main control unit, a transport control unit, a reading control unit, and an image processing unit, all of which are not shown. The main control unit is configured to comprehensively control the image reading device 11. The main control unit is configured to control the transport control unit, the reading control unit, and the image processing unit. The transport control unit is configured to control the feeding unit 21 and the conveying unit 26. The reading control unit is configured to control the reading unit 22. The image processing unit is configured to perform image processing on the image read by the reading unit 22.

[0037] Based on a reading instruction from a user, the control unit 42 performs control to read an image from the original document M. Specifically, the control unit 42 controls the feeding unit 21 to feed one sheet of the original document M placed on the placement unit 19. The control unit 42 controls the transport unit 26 to transport the one sheet of the original document M fed by the feeding unit 21 in the transport direction D1.

[0038] The control unit 42 controls the reading unit 22 to read an image from the original document M being transported in the transport direction D1, based on the second original document detection unit 30 detecting the leading edge of the original document M. The control unit 42 is configured to perform image processing based on the image read from the original document M. The control unit 42 is configured to output image data that has undergone image processing.

[0039] In this embodiment, the image reading device 11 stops the transport of the original M when the tilt angle of the transported original M exceeds a specified angle based on the image read from the original M. The original M may be damaged if it is transported at an angle when the image is read. For this reason, the image reading device 11 can protect the original M by stopping the transport of the original M.

[0040] <Receipt paper> The image reading device 11 of this embodiment can read images from receipt paper as an example of document M. The width of receipt paper may be, for example, 58 mm or 80 mm. The image reading device 11 can determine that the document M is receipt paper based on the width of the document M.

[0041] Receipt paper is printed by a printing device (not shown). Before printing, receipt paper is roll paper. After printing, receipt paper is produced by cutting it from the roll paper.

[0042] The cutting methods used by printers include full cut and partial cut. The full cut method cuts the entire width of the receipt paper. The partial cut method cuts the entire width of the receipt paper, leaving a specified area uncut.

[0043] The predetermined location may be, for example, one point, or multiple points. The predetermined location may be a corner position in the receipt width of the receipt paper, or the center position in the receipt width of the receipt paper. The predetermined location may be a location other than a corner position or the center position in the receipt width of the receipt paper.

[0044] When receipt paper is cut using the partial cut method, it remains connected to the roll paper at a specified point even after being ejected from the printer. This prevents the receipt paper from falling out of the printer and allows the operator to manually separate it from the roll paper.

[0045] For this reason, as shown in FIGS. 2 and 3, when receipt paper is cut using the partial cut method, partial cut marks 59A and 59B may be formed at the leading or trailing edge of the receipt paper.

[0046] The partial cut marks 59A and 59B are cut marks that are formed at the leading or trailing edge of the receipt paper when the receipt paper is cut using the partial cut method. The partial cut marks 59A and 59B may be convex relative to the leading or trailing edge of the receipt paper.

[0047] When the image reading device 11 of this embodiment determines that the document M is receipt paper, it can protect the receipt paper during transport even if there are partial cut marks 59A and 59B on the receipt paper.

[0048] <Image area 50> 2, the control unit 42 acquires image data as a result of the reading unit 22 reading an image from the document M. The image data has an image area 50. In other words, the image area 50 is the area of ​​the image read by the reading unit 22.

[0049] The image area 50 is an area partitioned in the width direction X and the height direction Y. The image area 50 is an area made up of a plurality of pixels in each of the width direction X and the height direction Y. Coordinates can be assigned to each of a plurality of pixels in the image area 50 in each of the width direction X and the height direction Y.

[0050] The width direction X is a direction intersecting with the height direction Y. The width direction X is a direction along the scanning direction D2. The height direction Y is a direction along the transport direction D1 of the original M. Hereinafter, one of the width directions X will be referred to as the first width direction X1, and the other of the width directions X will be referred to as the second width direction X2. One of the height directions Y will be referred to as the first height direction Y1, and the other of the height directions Y will be referred to as the second height direction Y2. The first height direction Y1 corresponds to the transport direction D1 of the original M. The second height direction Y2 corresponds to the opposite direction of the transport direction D1 of the original M. In other words, the width direction X is a direction intersecting with the transport direction D1. The second width direction X2 corresponds to the scanning direction D2. A coordinate in the width direction X of the image area 50 may be referred to as an X coordinate, and a coordinate in the height direction Y of the image area 50 may be referred to as a Y coordinate. The X coordinate and the Y coordinate may be collectively referred to simply as coordinates.

[0051] The image area 50 has a plurality of image edge sides 50A. Each of the plurality of image edge sides 50A is a side that constitutes an image edge of the image read by the reading unit 22. Specifically, the image area 50 includes a first image edge side 51, a second image edge side 52, and a third image edge side 53. The first image edge side 51 is the edge of the plurality of image edge sides 50A that is on the first height direction Y1 side. The second image edge side 52 is the edge of the plurality of image edge sides 50A that is on the first width direction X1 side. The third image edge side 53 is the edge of the plurality of image edge sides 50A that is on the second width direction X2 side.

[0052] The image area 50 includes an original area 54 and a non-original area 55. The original area 54 is an area corresponding to an image read from the original M. The non-original area 55 is an area corresponding to an image read from the background plate 33.

[0053] The document area 54 has a plurality of end edges 54A. Each of the end edges 54A is a document end edge that constitutes an end of the document area 54. Specifically, the document area 54 includes a first end edge 56, a second end edge 57, and a third end edge 58. The first end edge 56 is the end edge of the plurality of end edges 54A on the first height direction Y1 side. The second end edge 57 is the end edge of the document area 54 on the first width direction X1 side. The third end edge 58 is the end edge of the document area 54 on the second width direction X2 side.

[0054] In this way, the first edge 56 is located on the first image edge 51 side of the image area 50. In other words, the first image edge 51 is the image edge on the first edge 56 side. The second edge 57 is located on the second image edge 52 side of the image area 50. The third edge 58 is located on the third image edge 53 side of the image area 50.

[0055] The document area 54 is an area that spans the document width W in the width direction X. The document width W is the longest width of the document area 54 in the width direction X. When the document M is tilted, the document width W becomes longer than the actual width of the document M.

[0056] The image area 50 has a first reference position 61. The first reference position 61 is provided in the document area 54. The first reference position 61 is the position in the document area 54 that is closest to the first height direction Y1. The first reference position 61 is a position for determining the inclination angle of the document M.

[0057] The first reference position 61 is included in at least the first end side 56. The first reference position 61 may be included in the second end side 57 or the third end side 58. In other words, the first reference position 61 may be a vertex on the first end side 56 side, or a corner position of the first end side 56.

[0058] The image area 50 has a second reference position 62. The second reference position 62 is provided in the document area 54. The second reference position 62 is the position closest to the first height direction Y1 among the positions where the length of the document area 54 in the width direction X is greatest. The second reference position 62 is a position for determining the inclination angle of the document M.

[0059] The second reference position 62 is included in at least the first end side 56. The second reference position 62 may be included in the second end side 57 or the third end side 58. In other words, the second reference position 62 may be a vertex on the first end side 56 side, or a corner position of the first end side 56.

[0060] In this way, the combination of the first reference position 61 and the second reference position 62 is a combination of two vertices on the first end side 56 side of the first end side 56. For example, the combination of the first reference position 61 and the second reference position 62 may be a combination of a first corner position of the first end side 56 and a second corner position of the first end side 56.

[0061] The image area 50 has a first straight line 69. The first straight line 69 is a straight line that passes through the first reference position 61 and the second reference position 62. The first straight line 69 may be a line segment connecting the first reference position 61 and the second reference position 62, or may be a virtual line that passes through the first reference position 61 and the second reference position 62. The first straight line 69 can be expressed as a linear function that passes through the first reference position 61 and the second reference position 62. The first straight line 69 is a straight line that forms a first angle d1 with respect to the width direction X. In other words, the first angle d1 is the angle that the first straight line 69 makes with respect to the width direction X.

[0062] The image area 50 has a first end position 71. The first end position 71 is provided in the image area 50. The first end position 71 is included in the first end edge 56. The first end position 71 is a position between the first reference position 61 and the second reference position 62. The first end position 71 is a position that is a first distance L1 away from the first reference position 61 toward the second reference position 62 in the width direction X. The first distance L1 may be, for example, 10 mm, but is not limited to this. The first end position 71 is a position that is a third distance L3 away from the first image end edge 51 in the second height direction Y2. The first end position 71 is a position for determining the inclination angle of the document M.

[0063] The image area 50 has a second end position 72. The second end position 72 is provided in the image area 50. The second end position 72 is included in the first end edge 56. The second end position 72 is a position between the first reference position 61 and the second reference position 62. The second end position 72 is a position that is a second distance L2 away from the first reference position 61 toward the second reference position 62 in the width direction X. The second distance L2 is longer than the first distance L1. The second distance L2 may be, for example, 20 mm, but is not limited to this. The second end position 72 is a position that is a fourth distance L4 away from the first image end edge 51 in the second height direction Y2. The second end position 72 is a position for determining the inclination angle of the document M.

[0064] The image area 50 has a second straight line 79. The second straight line 79 is a line that passes through the first end position 71 and the second end position 72. The second straight line 79 may be a line segment connecting the first end position 71 and the second end position 72, or may be a virtual line that passes through the first end position 71 and the second end position 72. The second straight line 79 can be expressed as a linear function that passes through the first end position 71 and the second end position 72. The second straight line 79 is a line that makes a second angle d2 with respect to the width direction X. In other words, the second angle d2 is the angle that the second straight line 79 makes with respect to the width direction X.

[0065] The image area 50 includes a prohibited area R1 and an allowable area R2. The prohibited area R1 and the allowable area R2 are defined in the image area 50. The prohibited area R1 includes a first prohibited area R11 and a second prohibited area R12. The first prohibited area R11 is an area separated from the first reference position 61 by a specified distance L10 toward the second reference position 62 in the width direction X. The second prohibited area R12 is an area separated from the second reference position 62 by a specified distance L10 toward the first reference position 61 in the width direction X. In this case, the specified distance L10 is a distance corresponding to the width of the partial cut mark 59A, and may be, but is not limited to, 5 mm. The prohibited area R1 is an area in which the first end position 71 and the second end position 72 are not set. The prohibited area R1 corresponds to an example of a first area.

[0066] The allowable region R2 is a region different from the prohibited region R1. The allowable region R2 is a region sandwiched between a first prohibited region R11 and a second prohibited region R12 in the width direction X. The allowable region R2 is a region in which the first end position 71 and the second end position 72 can be set. In other words, the first end position 71 and the second end position 72 are located in the allowable region R2. The allowable region R2 corresponds to an example of the second region.

[0067] The image area 50 has a third reference position 63. The third reference position 63 is provided in the image area 50. The third reference position 63 is included in the first straight line 69. The third reference position 63 is a position that is a first distance L1 away from the first reference position 61 toward the second reference position 62 in the width direction X. The third reference position 63 is a position that is a fifth distance L5 away from the first image edge 51 in the second height direction Y2. The third reference position 63 is a position for determining the inclination angle of the document M.

[0068] The image area 50 has a fourth reference position 64. The fourth reference position 64 is provided in the image area 50. The fourth reference position 64 is included in the first straight line 69. The fourth reference position 64 is a position that is a second distance L2 away from the first reference position 61 toward the second reference position 62 in the width direction X. The fourth reference position 64 is a position that is a sixth distance L6 away from the first image edge 51 in the second height direction Y2. The fourth reference position 64 is a position for determining the inclination angle of the document M.

[0069] In this embodiment, if receipt paper with partial cut marks 59A is used as the document M, the first reference position 61 may be the area where the partial cut marks 59A are located. For example, when reading an image from receipt paper with partial cut marks 59A at a corner of the receipt paper, the first reference position 61 may be the corner where the partial cut marks 59A are located.

[0070] In such a case, if the inclination angle of the original M is determined based on the first straight line 69 that passes through the first reference position 61 and the second reference position 62, an error will occur with respect to the actual inclination angle of the original M. For this reason, in this embodiment, when both the first end position 71 and the second end position 72 are on the second height direction Y2 side of the first straight line 69, the inclination angle of the original M is determined based on the second straight line 79, not the first straight line 69.

[0071] Similar control can be performed when the first reference position 61 is located further in the first width direction X1 than the second reference position 62, and when it is located further in the second width direction X2 than the second reference position 62. Similar control can be performed when the first reference position 61 is located in the area where the partial cut mark 59A is formed, and when the second reference position 62 is located in the area where the partial cut mark 59A is formed.

[0072] 3, for example, an image may be read from receipt paper that has a partial cut mark 59B in the center of the receipt paper. In such a case, the first reference position 61 may be the center position of the partial cut mark 59B. In other words, the combination of the first reference position 61 and the second reference position 62 may be the combination of the center position of the first end side 56 and the first corner position of the first end side 56.

[0073] In this case, the first prohibited area R11 may be an area that is separated from the first reference position 61 toward the second reference position 62 in the width direction X by a first specified distance L11. The second prohibited area R12 may be an area that is separated from the second reference position 62 toward the first reference position 61 in the width direction X by a second specified distance L12. The first specified distance L11 is a distance equivalent to half the width of the partial cut mark 59B and may be, for example, 2.5 mm. The second specified distance L12 is a distance equivalent to the width of the partial cut mark 59B and may be, for example, 5 mm. The specified distance L10 may include the first specified distance L11 and the second specified distance L12. In other words, the specified distance L10 may be 5 mm or less.

[0074] Even in such a case, if both the first end position 71 and the second end position 72 are on the second height direction Y2 side of the first straight line 69, the inclination angle of the document M is determined based on the second straight line 79, not the first straight line 69. If there are no partial cut marks 59A, 59B on the first end side 56, the first end position 71 and the second end position 72 are on the first straight line 69, and the inclination angle of the document M is determined based on the first angle d1.

[0075] <Document transport monitoring process> Here, the document transport monitoring process will be described with reference to Figures 4 and 5. The document transport monitoring process is executed by the control unit 42 when a predetermined execution condition is met when an image is read from the document M based on a reading instruction from the user. The predetermined execution condition may be met when the control unit 42 receives an image read from the document M by the reading unit 22.

[0076] In step S11, the control unit 42 executes a first reference position acquisition process. In the first reference position acquisition process, the control unit 42 acquires the first reference position 61 from the image read by the reading unit 22.

[0077] More specifically, the control unit 42 analyzes the image read by the reading unit 22 from the document M transported along the transport path 16. The control unit 42 acquires the first position in the image area 50 that is identified as the document area 54 along the width direction X, starting from the first height direction Y1, as the coordinates of the first reference position 61. In other words, the control unit 42 acquires the position in the document area 54 that is closest to the first height direction Y1 as the coordinates of the first reference position 61. In this embodiment, the control unit 42 may repeatedly execute step S11 until it acquires the first reference position 61 by identifying the document area 54.

[0078] In step S12, the control unit 42 executes a second reference position acquisition process. In the second reference position acquisition process, the control unit 42 acquires the second reference position 62 from the image read by the reading unit 22.

[0079] Specifically, the control unit 42 analyzes the image read by the reading unit 22 from the document M transported along the transport path 16. The control unit 42 calculates the width of the document area 54 in the width direction X, starting from the first height direction Y1. For example, the control unit 42 calculates the distance from the second image edge 52 to the document area 54 in the second width direction X2. The control unit 42 calculates the distance from the third image edge 53 to the document area 54 in the first width direction X1. The control unit 42 may calculate the width of the document area 54 in the width direction X by subtracting the sum of the distance from the second image edge 52 to the document area 54 and the distance from the third image edge 53 to the document area 54 from the overall width of the first image edge 51.

[0080] The control unit 42 acquires, as the coordinates of the second reference position 62, the position where the width of the document area 54 in the width direction X is at its maximum and where the distance between the second image edge 52 or the third image edge 53 and the document area 54 in the width direction X is greatest. In other words, the control unit 42 acquires, as the coordinates of the second reference position 62, the vertex where the width of the document area 54 in the width direction X is at its maximum and which is closest to the first height direction Y1. In this embodiment, the control unit 42 may repeatedly execute step S12 by specifying the document width W until it acquires the second reference position 62.

[0081] In step S13, the control unit 42 executes a document width acquisition process, in which the control unit 42 acquires the maximum length of the width of the document area 54 in the width direction X as the document width W.

[0082] In step S14, the control unit 42 determines whether the document width W is 50 mm or more and 90 mm or less. In other words, the control unit 42 determines that the document M is receipt paper when the document width W is 50 mm or more and 90 mm or less. The reference range of 50 mm or more and 90 mm or less is a range that takes into account the receipt width of the receipt paper and the tilt angle of the conveyed receipt paper, but is not limited to this as long as it is within a range in which the document M can be determined to be receipt paper.

[0083] If the control unit 42 determines that the document width W is 50 mm or more and 90 mm or less, the process proceeds to step S15. If the control unit 42 determines that the document width W is not 50 mm or more and 90 mm or less, the process proceeds to step S23 in FIG. 5.

[0084] In step S15, the control unit 42 executes a first end position acquisition process. In the first end position acquisition process, the control unit 42 acquires the coordinates of the first end position 71 from the image read by the reading unit 22.

[0085] Specifically, the control unit 42 acquires, as the coordinate of the first end position 71, a position that is included in the first end side 56 and that is separated from the first reference position 61 toward the second reference position 62 by the first distance L1 in the width direction X from the first reference position 61 toward the second reference position 62. For example, the control unit 42 acquires, as the X coordinate of the first end position 71, a coordinate that is separated from the first reference position 61 toward the second reference position 62 in the width direction X. The control unit 42 may acquire, as the Y coordinate of the first end position 71, a position on the first image end side 51 that first becomes part of the document area 54 in the second height direction Y2 from the X coordinate of the first end position 71. In this way, the control unit 42 acquires the coordinate of the first end position 71 from the image area 50 based on the coordinate of the first reference position 61, the coordinate of the second reference position 62, and the first distance L1.

[0086] In step S16, the control unit 42 executes a second end position acquisition process. In the second end position acquisition process, the control unit 42 acquires the coordinates of the second end position 72 from the image read by the reading unit 22.

[0087] Specifically, the control unit 42 acquires, as the coordinate of the second end position 72, a position that is included in the first end side 56 and that is separated from the first reference position 61 toward the second reference position 62 by the second distance L2 in the width direction X from the first reference position 61 toward the second reference position 62. For example, the control unit 42 acquires, as the X coordinate of the second end position 72, a coordinate that is separated from the first reference position 61 toward the second reference position 62 in the width direction X. The control unit 42 may acquire, as the Y coordinate of the second end position 72, a position on the first image end side 51 that first becomes part of the document area 54 in the second height direction Y2 from the X coordinate of the second end position 72. In this way, the control unit 42 acquires the coordinate of the second end position 72 from the image area 50 based on the coordinate of the first reference position 61, the coordinate of the second reference position 62, and the second distance L2.

[0088] In step S17, the control unit 42 executes a third reference position acquisition process. In the third reference position acquisition process, the control unit 42 acquires the third reference position 63 from the image read by the reading unit 22.

[0089] Specifically, the control unit 42 acquires, as the X coordinate of the third reference position 63, a position that is the first distance L1 away from the first reference position 61 toward the second reference position 62 in the width direction X, based on the coordinate of the first reference position 61 and the first distance L1. The control unit 42 may acquire the X coordinate of the first end position 71 as the X coordinate of the third reference position 63. The control unit 42 acquires the Y coordinate of the third reference position 63 based on the coordinate of the first reference position 61, the coordinate of the second reference position 62, and the X coordinate of the third reference position 63. The third reference position 63 is a position on a first line 69 that passes through the coordinate of the first reference position 61 and the coordinate of the second reference position 62, and that has the same X coordinate as the first end position 71.

[0090] In this way, the control unit 42 acquires the coordinates of the third reference position 63 based on the coordinates of the first reference position 61, the coordinates of the second reference position 62, and the first distance L1. That is, the control unit 42 acquires, as the coordinates of the third reference position 63, a position that is included in the first straight line 69 and that is separated from the first reference position 61 toward the second reference position 62 in the width direction X by the first distance L1.

[0091] In step S18, the control unit 42 executes a fourth reference position acquisition process. In the fourth reference position acquisition process, the control unit 42 acquires the fourth reference position 64 from the image read by the reading unit 22.

[0092] Specifically, based on the coordinate of the first reference position 61 and the second distance L2, the control unit 42 acquires, as the X coordinate of the fourth reference position 64, a position that is away from the first reference position 61 by the second distance L2 toward the second reference position 62 in the width direction X. The control unit 42 may acquire the X coordinate of the second end position 72 as the X coordinate of the fourth reference position 64. The control unit 42 acquires the Y coordinate of the fourth reference position 64 based on the coordinate of the first reference position 61, the coordinate of the second reference position 62, and the X coordinate of the fourth reference position 64. The fourth reference position 64 is a position on the first line 69 that passes through the coordinate of the first reference position 61 and the coordinate of the second reference position 62, and that has the same X coordinate as the second end position 72.

[0093] In this way, the control unit 42 acquires the coordinates of the fourth reference position 64 based on the coordinates of the first reference position 61, the coordinates of the second reference position 62, and the second distance L2. That is, the control unit 42 acquires, as the coordinates of the fourth reference position 64, a position that is included in the first straight line 69 and that is separated from the first reference position 61 toward the second reference position 62 in the width direction X by the second distance L2.

[0094] In step S19, the control unit 42 executes a distance acquisition process. In the distance acquisition process, the control unit 42 acquires a third distance L3, a fourth distance L4, a fifth distance L5, and a sixth distance L6.

[0095] Specifically, the control unit 42 calculates the distance between the first image edge 51 and the first edge position 71 in the height direction Y based on the coordinates of the first edge position 71. The control unit 42 acquires the calculation result as a third distance L3. The control unit 42 calculates the distance between the first image edge 51 and the second edge position 72 in the height direction Y based on the coordinates of the second edge position 72. The control unit 42 acquires the calculation result as a fourth distance L4. The control unit 42 calculates the distance between the first image edge 51 and the third reference position 63 in the height direction Y based on the coordinates of the third reference position 63. The control unit 42 acquires the calculation result as a fifth distance L5. The control unit 42 calculates the distance between the first image edge 51 and the fourth reference position 64 in the height direction Y based on the coordinates of the fourth reference position 64. The control unit 42 acquires the calculation result as a sixth distance L6.

[0096] In step S20, the control unit 42 determines whether the third distance L3 is greater than the fifth distance L5 and whether the fourth distance L4 is greater than the sixth distance L6. If the control unit 42 determines that the third distance L3 is greater than the fifth distance L5 and that the fourth distance L4 is greater than the sixth distance L6, the control unit 42 proceeds to step S21 in Fig. 5. If the control unit 42 determines that the third distance L3 is equal to or less than the fifth distance L5 or that the fourth distance L4 is equal to or less than the sixth distance L6, the control unit 42 proceeds to step S23 in Fig. 5.

[0097] 5, in step S21, the control unit 42 executes a second angle acquisition process. In the second angle acquisition process, the control unit 42 acquires a second angle d2. Specifically, the control unit 42 calculates the inclination angle of the second straight line 79 with respect to the width direction X based on the coordinates of the first end position 71 and the coordinates of the second end position 72. The control unit 42 acquires the calculation result as the second angle d2.

[0098] In step S22, the control unit 42 executes a second angle setting process. In the second angle setting process, the control unit 42 sets the second angle d2 as the tilt angle. In this way, the control unit 42 sets the second angle d2 as the tilt angle when the first end position 71 is closer to the third reference position 63 in the second height direction Y2 and the second end position 72 is closer to the fourth reference position 64 in the second height direction Y2. In other words, the control unit 42 sets the second angle d2 as the tilt angle when both the first end position 71 and the second end position 72 are closer to the first straight line 69 in the second height direction Y2.

[0099] In step S23, the control unit 42 executes a first angle acquisition process. In the first angle acquisition process, the control unit 42 acquires a first angle d1. Specifically, the control unit 42 calculates the inclination angle of the first straight line 69 with respect to the width direction X based on the coordinates of the first reference position 61 and the coordinates of the second reference position 62. The control unit 42 acquires the calculation result as the first angle d1.

[0100] In step S24, the control unit 42 executes a first angle setting process. In the first angle setting process, the control unit 42 sets the first angle d1 as the tilt angle. In this way, the control unit 42 sets the first angle d1 as the tilt angle when the first end position 71 is not on the second height direction Y2 side of the third reference position 63 or when the second end position 72 is not on the second height direction Y2 side of the fourth reference position 64. In other words, the control unit 42 sets the first angle d1 as the tilt angle when at least one of the first end position 71 and the second end position 72 is not on the second height direction Y2 side of the first straight line 69.

[0101] In step S25, the control unit 42 determines whether the set tilt angle exceeds a specified angle. This determination is also called skew determination. If the control unit 42 determines that the tilt angle exceeds the specified angle, the control unit 42 proceeds to step S26. If the control unit 42 determines that the tilt angle does not exceed the specified angle, the control unit 42 ends the document transport monitoring process.

[0102] In step S26, the control unit 42 executes a transport stop process. In the transport stop process, the control unit 42 controls the transport unit 26 to stop the transport of the document M. In this way, when the first angle d1 is set as the tilt angle, the control unit 42 stops the transport of the document M when the first angle d1 exceeds a specified angle. When the second angle d2 is set as the tilt angle, the control unit 42 stops the transport of the document M when the second angle d2 exceeds the specified angle.

[0103] In step S27, the control unit 42 executes a notification process. In the notification process, the control unit 42 causes the display unit 41 to display an image related to the rereading of the document M. In this way, the control unit 42 performs a notification related to the rereading of the document M.

[0104] <Actions and Effects of the First Embodiment> The operation and effects of the first embodiment will be described. (1-1) When a document M is transported in which either the first reference position 61 or the second reference position 62 is not on the second straight line 79, both the first end position 71 and the second end position 72 are located on the second height direction Y2 side of the first straight line 69. In such a case, the transport of the document M can be stopped based on the second straight line 79 rather than the first straight line 69. This makes it possible to prevent a decrease in the calculation accuracy regarding the inclination angle of the document M being transported, even if the document M has a shape in which either the first reference position 61 or the second reference position 62 is not linear at the first end edge 56. Therefore, the execution accuracy of stopping the transport of the document M can be improved.

[0105] To give a specific example, when a document M having partial cut marks 59A and 59B at the first reference position 61 on the first end side 56 is transported, both the first end position 71 and the second end position 72 are located on the second height direction Y2 side of the first straight line 69. In such a case, the inclination angle of the document M is the second angle d2, not the first angle d1.

[0106] When the first angle d1 with respect to the width direction X exceeds the specified angle but the second angle d2 does not exceed the specified angle, the actual tilt angle of the original document M does not exceed the specified angle, but if the first angle d1 is used as a reference, the conveyance of the original document M will be stopped. As in the present embodiment, the control unit 42 uses the second angle d2, which is the actual tilt angle of the original document M, as a reference and therefore does not stop the conveyance of the original document M.

[0107] When the second angle d2 with respect to the width direction X exceeds the specified angle but the first angle d1 does not exceed the specified angle, the actual tilt angle of the original M exceeds the specified angle, but if the first angle d1 is used as the reference, the conveyance of the original M is not stopped. As in the present embodiment, the control unit 42 uses the second angle d2, which is the actual tilt angle of the original M, as the reference, and therefore can stop the conveyance of the original M.

[0108] (1-2) When the first end position 71 is closer to the third reference position 63 in the second height direction Y2 and the second end position 72 is closer to the fourth reference position 64 in the second height direction Y2, both the first end position 71 and the second end position 72 are closer to the first straight line 69 in the second height direction Y2. In such a case, the transport of the document M can be stopped based on the second straight line 79 rather than the first straight line 69. This prevents a decrease in the accuracy of calculation of the inclination angle of the document M being transported, even if the document M has a shape in which either the first reference position 61 or the second reference position 62 is not linear at the first end edge 56. This improves the accuracy of stopping the transport of the document M.

[0109] (1-3) Even if the shape of the original M is such that one of the two vertices on the first end side 56 side is not linear at the first end side 56, it is possible to suppress a decrease in the calculation accuracy regarding the inclination angle of the original M being conveyed. Therefore, it is possible to improve the execution accuracy of stopping the conveyance of the original M.

[0110] (1-4) Even if the shape of the original document M is such that either the first corner position or the second corner position on the first end side 56 side is not linear at the first end side 56, it is possible to suppress a decrease in the calculation accuracy regarding the inclination angle of the original document M being conveyed. Therefore, it is possible to improve the execution accuracy of stopping the conveyance of the original document M.

[0111] (1-5) Even if the shape of the original document M is such that either the first corner position or the central position on the first end side 56 side is not linear at the first end side 56, it is possible to suppress a decrease in the calculation accuracy regarding the inclination angle of the original document M being conveyed. Therefore, it is possible to improve the execution accuracy of stopping the conveyance of the original document M.

[0112] (1-6) The first end position 71 and the second end position 72 are not provided in the prohibited area R1 that is a specified distance L10 away from the first reference position 61 and the second reference position 62 in the width direction X. As a result, even if the shape of the document M is such that either the first reference position 61 or the second reference position 62 is not linear at the first end side 56, the first end position 71 and the second end position 72 can be provided on a straight line at the first end side 56. This makes it possible to suppress a decrease in the calculation accuracy regarding the inclination angle of the document M being transported. Therefore, it is possible to improve the execution accuracy of stopping the transport of the document M.

[0113] (1-7) The first end position 71 and the second end position 72 are not provided in the prohibited area R1 that is 5 mm or less in the width direction X from the first reference position 61 and the second reference position 62. As a result, even if the shape of the document M is such that either the first reference position 61 or the second reference position 62 is not linear at the first end side 56, the first end position 71 and the second end position 72 can be provided on a straight line at the first end side 56. This makes it possible to suppress a decrease in the calculation accuracy regarding the inclination angle of the document M being transported. Therefore, it is possible to improve the execution accuracy of stopping the transport of the document M.

[0114] (1-8) If the width of the document M in the width direction X is between 50 mm and 90 mm, it can be assumed that the document M is receipt paper. This prevents a decrease in the accuracy of calculation of the inclination angle of the document M being conveyed, even if the receipt paper has partial cut marks 59A and 59B. This improves the accuracy of stopping the conveyance of the document M.

[0115] (1-9) When the transport of the original M is stopped, a notification process regarding rereading of the original M can be executed. This can prompt the user to reread the original M. Therefore, it is possible to improve user convenience.

[0116] [Second embodiment] Next, a second embodiment will be described. In the following description, the same configuration as in the already described embodiment will be omitted or simplified, and only the configuration different from the already described embodiment will be described.

[0117] In the second embodiment, the control unit 42 may determine whether both the first end position 71 and the second end position 72 are located on the second height direction Y2 side of the first straight line 69 without using the third to sixth distances L3 to L6.

[0118] <Image area 50> As shown in FIGS. 2 and 3, the image area 50 has a fifth reference position 65. The fifth reference position 65 is included in the second straight line 79. The fifth reference position 65 is the same position as the first reference position 61 in the width direction X. The fifth reference position 65 is a position that is a seventh distance L7 away from the first image edge 51 in the second height direction Y2. The fifth reference position 65 is a position for determining the skew angle of the document M. The first reference position 61 is a position that is an eighth distance L8 away from the first image edge 51 in the second height direction Y2.

[0119] <Document transport monitoring process> 6, after step S16 is completed, the control unit 42 executes step S31. In step S31, the control unit 42 executes a fifth reference position acquisition process. In the fifth reference position acquisition process, the control unit 42 acquires a fifth reference position 65 from the image read by the reading unit 22.

[0120] Specifically, the control unit 42 acquires the Y coordinate of the fifth reference position 65 based on the coordinates of the first end position 71, the coordinates of the second end position 72, and the X coordinate of the first reference position 61. The fifth reference position 65 is a position on a second line 79 that passes through the coordinates of the first end position 71 and the coordinates of the second end position 72 and has the same X coordinate as the first reference position 61.

[0121] In this way, the control unit 42 acquires the coordinates of the fifth reference position 65 based on the coordinates of the first end position 71, the coordinates of the second end position 72, and the coordinates of the first reference position 61. In other words, the control unit 42 acquires, as the coordinates of the fifth reference position 65, a position that is included in the second straight line 79 and is the same as the first reference position 61 in the width direction X.

[0122] In step S32, the control unit 42 executes a distance acquisition process. In the distance acquisition process, the control unit 42 acquires a seventh distance L7 and an eighth distance L8. Specifically, the control unit 42 calculates the distance between the first image edge 51 and the fifth reference position 65 in the height direction Y based on the coordinates of the fifth reference position 65. The control unit 42 acquires the calculation result as the seventh distance L7. The control unit 42 calculates the distance between the first image edge 51 and the first reference position 61 in the height direction Y based on the coordinates of the first reference position 61. The control unit 42 acquires the calculation result as the eighth distance L8.

[0123] In step S33, the control unit 42 determines whether the seventh distance L7 is greater than the eighth distance L8. If the control unit 42 determines that the seventh distance L7 is greater than the eighth distance L8, the control unit 42 proceeds to step S21 in Fig. 5. If the control unit 42 determines that the seventh distance L7 is equal to or less than the eighth distance L8, the control unit 42 proceeds to step S23 in Fig. 5.

[0124] In this way, when either the first reference position 61 or the second reference position 62 is located closer to the first height direction Y1 than the second straight line 79, the control unit 42 stops the transport of the original M when the second angle d2 exceeds the specified angle.

[0125] <Actions and Effects of the Second Embodiment> The operation and effects of the second embodiment will be described. (2-1) When either the first reference position 61 or the second reference position 62 is located closer to the second straight line 79 in the first height direction Y1, both the first end position 71 and the second end position 72 are located closer to the first straight line 69 in the second height direction Y2. In such a case, the transport of the original document M can be stopped based on the second straight line 79 rather than the first straight line 69. This makes it possible to prevent a decrease in the accuracy of calculation of the inclination angle of the transported original document M, even if the shape of the original document M is such that either the first reference position 61 or the second reference position 62 is not linear at the first end edge 56. Therefore, the accuracy of stopping the transport of the original document M can be improved.

[0126] [Third embodiment] Next, a third embodiment will be described. In the third embodiment, the control unit 42 may determine whether both the first end position 71 and the second end position 72 are located on the second height direction Y2 side of the first straight line 69 based on the first straight line 69 and the second straight line 79, without using the third to eighth distances L3 to L8.

[0127] After acquiring the first reference position 61 and the second reference position 62, the control unit 42 acquires a first angle d1 based on the coordinates of the first reference position 61 and the coordinates of the second reference position 62. After acquiring the first end position 71 and the second end position 72, the control unit 42 acquires a second angle d2 based on the coordinates of the first end position 71 and the coordinates of the second end position 72.

[0128] For example, the control unit 42 may set the tilt angle based on the determination result of whether the first angle d1 and the second angle d2 are the same. If the first angle d1 and the second angle d2 are the same, the control unit 42 sets the first angle d1 as the tilt angle. If the first angle d1 and the second angle d2 are not the same, the control unit 42 sets the second angle d2 as the tilt angle.

[0129] For example, the control unit 42 may determine, from the coordinates of the intersection between the first straight line 69 and the second straight line 79, whether the first angle d1 and the second angle d2 are such that the second straight line 79 extends further toward the second height direction Y2 than the first straight line 69 in the width direction X toward the document area 54.

[0130] <Actions and Effects of the Third Embodiment> The operation and effects of the third embodiment will be described. (3-1) When the second straight line 79 is closer to the second height direction Y2 than the first straight line 69, both the first end position 71 and the second end position 72 are closer to the first straight line 69 in the second height direction Y2. In such a case, the transport of the original document M can be stopped based on the second straight line 79 rather than the first straight line 69. This makes it possible to prevent a decrease in the accuracy of calculation of the inclination angle of the transported original document M, even if the shape of the original document M is such that either the first reference position 61 or the second reference position 62 is not linear at the first end side 56. Therefore, the accuracy of stopping the transport of the original document M can be improved.

[0131] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0132] The control unit 42 may execute various processes in any order. For example, the control unit 42 may calculate the second angle d2 when acquiring the first end position 71 and the second end position 72. For example, in the first embodiment, the control unit 42 may calculate the first angle d1 when acquiring the third reference position 63 and the fourth reference position 64. For example, in the second embodiment, the control unit 42 may calculate the second angle d2 when acquiring the fifth reference position 65.

[0133] In the first embodiment, the control unit 42 may set the second line 79 as the inclination angle when the difference between the third distance L3 and the fifth distance L5 is equal to or greater than a first threshold value and the difference between the fourth distance L4 and the sixth distance L6 is equal to or greater than a second threshold value. In the second embodiment, the control unit 42 may set the second line 79 as the inclination angle when the difference between the seventh distance L7 and the eighth distance L8 is equal to or greater than a threshold value.

[0134] The first and second thresholds may correspond to an allowable error range for each distance difference. The first and second thresholds may be values ​​corresponding to the lengths of the partial cut marks 59A, 59B in the height direction Y, the first distance L1, and the second distance L2. The first and second thresholds may be the same value. The first threshold may be a threshold based on the first distance L1, and the second threshold may be a threshold based on the second distance L2. When the second reference position 62 is the coordinates of the intersection of the first line 69 and the second line 79, the first threshold may be greater than the second threshold. When the first reference position 61 is the coordinates of the intersection of the first line 69 and the second line 79, the first threshold may be smaller than the second threshold.

[0135] In the first embodiment, the control unit 42 does not have to acquire the third distance L3, the fourth distance L4, the fifth distance L5, and the sixth distance L6. In this case, the control unit 42 may determine that the first end position 71 is closer to the third reference position 63 in the second height direction Y2 based on the Y coordinate of the first end position 71 and the Y coordinate of the third reference position 63. The control unit 42 may determine that the second end position 72 is closer to the fourth reference position 64 in the second height direction Y2 based on the Y coordinate of the second end position 72 and the Y coordinate of the fourth reference position 64.

[0136] In the second embodiment, the control unit 42 does not need to acquire the seventh distance L7 and the eighth distance L8. In this case, the control unit 42 may determine that the fifth reference position 65 is further in the second height direction Y2 than the first reference position 61, based on the Y coordinate of the fifth reference position 65 and the Y coordinate of the first reference position 61.

[0137] In the transport stop processing, the control unit 42 may stop the transport of the original M and then transport the original M in the direction opposite to the transport direction D1. In the transport stop processing, the control unit 42 may slow down the transport speed without completely stopping the transport of the original M.

[0138] The control unit 42 may acquire three or more end positions on the first edge 56 that are at different distances from the first reference position 61 in the width direction X. The control unit 42 may acquire a common line among the lines passing through the three or more end positions as the second line 79. In this case, the control unit 42 may acquire two end positions on the second line 79 as the first end position 71 and the second end position 72. This makes it easier for the control unit 42 to acquire positions where the partial cut marks 59A and 59B are not formed as the first end position 71 and the second end position 72. This prevents a decrease in the accuracy of calculation of the inclination angle of the conveyed document M, even if the receipt paper has partial cut marks 59A and 59B. This improves the accuracy of stopping the conveyance of the document M.

[0139] The control unit 42 may determine, among the first reference position 61 and the second reference position 62, a reference position through which the second line 79 does not pass as the position where the partial cut marks 59A and 59B are formed. The control unit 42 may register the positions where the partial cut marks 59A and 59B are formed as history. The control unit 42 may register the positions where the partial cut marks 59A and 59B are formed as history so as to correspond to the document width W. The control unit 42 may learn the positions where the partial cut marks 59A and 59B are formed based on the registered history. The control unit 42 may estimate the positions where the partial cut marks 59A and 59B are formed based on the learning results. The control unit 42 may determine the specified distance L10 based on the results of estimating the positions where the partial cut marks 59A and 59B are formed. In other words, the control unit 42 may determine the prohibited area R1 and the allowed area R2 as a result of estimating the positions where the partial cut marks 59A and 59B are formed. The control unit 42 may determine the first distance L1 and the second distance L2 so that the first end position 71 and the second end position 72 are located within the determined allowable region R2.

[0140] The control unit 42 may determine the prohibited area R1. The control unit 42 may determine whether the first reference position 61 and the second reference position 62 are corner positions or central positions. If the first reference position 61 and the second reference position 62 are corner positions, the control unit 42 may determine the prohibited area R1 as the first specified distance L11. If the first reference position 61 and the second reference position 62 are central positions, the control unit 42 may determine the prohibited area R1 as the second specified distance L12.

[0141] The control unit 42 may perform skew determination regardless of the document width W. The control unit 42 may perform skew determination when a specific document M is set by the user as the type of document M. The control unit 42 may perform skew determination when the user sets it to perform skew determination. The control unit 42 may not perform skew determination when the user sets it not to perform skew determination.

[0142] When the first end position 71 is on the first straight line 69, the control unit 42 may stop the transport of the document M based on the first angle d1 without obtaining the second end position 72. When the first end position 71 is further from the first straight line 69 in the second height direction Y2, the control unit 42 may obtain the second end position 72 and determine whether the second end position 72 is further from the first straight line 69 in the second height direction Y2.

[0143] The control unit 42 may, depending on the user's setting, stop the transport of the original document M when the second angle d2 exceeds a specified angle, even if both the first end position 71 and the second end position 72 are on the second height direction Y2 side of the first straight line 69. The control unit 42 may, when the original document width W is within a reference range, stop the transport of the original document M when the second angle d2 exceeds a specified angle, even if both the first end position 71 and the second end position 72 are on the second height direction Y2 side of the first straight line 69. The control unit 42 may, regardless of the user's setting and the original document width W, stop the transport of the original document M when the second angle d2 exceeds a specified angle, even if both the first end position 71 and the second end position 72 are on the second height direction Y2 side of the first straight line 69.

[0144] The main control unit included in the control unit 42 may execute steps S26 and S27, and the image processing unit included in the control unit 42 may execute steps S11 to S25 and S31 to S33. In this case, if the image processing unit makes a positive determination in steps S25 and S33, it may output a conveyance stop instruction to the main control unit. When the conveyance stop instruction is input, the main control unit may output an instruction to the conveyance control unit to stop conveying the document M.

[0145] The control unit 42 may issue a notification from a speaker (not shown). The control unit 42 may issue a notification using a light-emitting unit (not shown). The control unit 42 may issue a notification to a terminal (not shown) instead of the image reading device 11.

[0146] The control unit 42 may switch whether or not to execute the notification process based on a setting made by the user as to whether or not to perform notification. The control unit 42 may not execute the notification process. The feed roller 24 may contact the back surface of the document M. The separation unit 25 may contact the front surface of the document M. In other words, the feed roller 24 may be provided below the transport path 16, and the separation roller may be provided above the transport path 16. The separation unit 25 may be a pad that sandwiches the document M between itself and the feed roller 24.

[0147] The manuscript M may be any of a receipt, bookmark, ribbon, strip of paper, chopstick wrapper, gift tag, tag paper, name tag, and the like. The image reading device 11 may be a multifunction device or a copying device mounted on a recording device such as a printer.

[0148] The phrase "at least any" used herein means one or more of the desired options. As an example, when the number of options is two, the phrase "at least any" used herein means only one option or both options. As another example, when the number of options is three or more, the phrase "at least any" used herein means only one option or any combination of two or more options.

[0149] [Note] The technical concepts and their effects that can be understood from the above-described embodiments and modifications will be described below. The technical concepts and their effects can be combined with each other to the extent that they are not technically inconsistent.

[0150] (A) An image reading device includes a conveying unit that conveys a document in a conveying direction, a reading unit that reads an image from the document conveyed by the conveying unit, and a control unit that controls the conveying unit and the reading unit, and when a direction intersecting the conveying direction is defined as a width direction, the control unit performs a first edge position acquisition process that acquires, from the image read by the reading unit, a first edge position that is between a first reference position and a second reference position that is included in a first edge of a document area on the conveying direction side, and that is included in the first edge; a second end position acquisition process for acquiring a second end position that is between the first reference position and the second reference position, is included in the first end edge, and is different from the first end position from the image; and a transport stop process for stopping transport of the document when an inclination angle of the second line that passes through the first end position and the second end position with respect to the width direction exceeds a specified angle, in a case where both the first end position and the second end position are on the opposite side of the transport direction from a first line that passes through the first reference position and the second reference position.

[0151] According to this configuration, when a document is being transported in which either the first reference position or the second reference position is not on the second straight line, both the first end position and the second end position are on the opposite side of the transport direction from the first straight line. In such a case, the transport of the document can be stopped based on the second straight line rather than the first straight line. This prevents a decrease in the accuracy of calculation of the inclination angle of the document being transported, even if the document has a shape in which either the first reference position or the second reference position is not linear at the first end edge. Therefore, the accuracy of stopping the transport of the document can be improved.

[0152] (B) In the image reading device, the first end position acquisition process includes a process of acquiring, as the first end position, a position that is included in the first end side and that is separated by a first distance from the first reference position toward the second reference position in the width direction, and the second end position acquisition process includes a process of acquiring, as the second end position, a position that is included in the first end side and that is separated by a second distance that is longer than the first distance from the first reference position toward the second reference position in the width direction, and the control unit acquires, from the image read by the reading unit, a position that is included in the first straight line and that is separated by the first distance from the first reference position toward the second reference position in the width direction, as a third reference position. a fourth reference position acquisition process for acquiring, from the image read by the reading unit, a position that is included in the first straight line and that is the second distance away from the first reference position toward the second reference position in the width direction as a fourth reference position, and when the image edge on the conveying direction side of the multiple image edge edges of the image read by the reading unit is defined as the first image edge edge, the conveying stop process may include a process for stopping conveyance of the document when the inclination angle of the second straight line with respect to the width direction exceeds a specified angle when the first end position is on the opposite side of the conveying direction from the third reference position and the second end position is on the opposite side of the conveying direction from the fourth reference position.

[0153] According to this configuration, when the first end position is located on the opposite side of the conveying direction from the third reference position and the second end position is located on the opposite side of the conveying direction from the fourth reference position, both the first end position and the second end position are located on the opposite side of the conveying direction from the first straight line. In such a case, the conveyance of the document can be stopped based on the second straight line rather than the first straight line. This prevents a decrease in the accuracy of calculation of the inclination angle of the document being conveyed, even if the document has a shape in which either the first reference position or the second reference position is not linear at the first edge. Therefore, the accuracy of stopping the conveyance of the document can be improved.

[0154] (C) In the above image reading device, the first end position acquisition process includes a process of acquiring as the first end position a position that is included in the first end edge and that is a first distance away from the first reference position in the width direction toward the document area, and the second end position acquisition process includes a process of acquiring as the second end position a position that is included in the first end edge and that is a second distance longer than the first distance away from the first reference position in the width direction toward the document area, and when the image end edge on the transport direction side of the multiple image end edges of the image read by the reading unit is the first image end edge, the transport stop process may include a process of stopping transport of the document when the inclination angle of the second straight line with respect to the width direction exceeds a specified angle when either the first reference position or the second reference position is on the transport direction side of the second straight line.

[0155] According to this configuration, when either the first reference position or the second reference position is located closer to the second line in the transport direction than the second line, both the first end position and the second end position are located on the opposite side of the first line in the transport direction. In such a case, the transport of the document can be stopped based on the second line rather than the first line. This prevents a decrease in the accuracy of calculation of the inclination angle of the document being transported, even if the document has a shape in which either the first reference position or the second reference position is not linear at the first end edge. Therefore, the accuracy of stopping the transport of the document can be improved.

[0156] (D) In ​​the image reading device, the combination of the first reference position and the second reference position may be a combination of two vertices on the first side. According to this configuration, even if the document has a shape in which one of the two vertices on the first edge side is not linear at the first edge side, it is possible to suppress a decrease in the accuracy of calculation of the inclination angle of the document being conveyed, thereby improving the accuracy of stopping the conveyance of the document.

[0157] (E) In the image reading device, the combination of the first reference position and the second reference position may include a combination of a first corner position of the first end side and a second corner position of the first end side.

[0158] According to this configuration, even if the document has a shape in which either the first corner position or the second corner position on the first edge side is not linear on the first edge side, it is possible to suppress a decrease in the accuracy of calculation of the inclination angle of the document being conveyed, thereby improving the accuracy of stopping the conveyance of the document.

[0159] (F) In the image reading device, the combination of the first reference position and the second reference position may include a combination of a first corner position of the first end side and a center position of the first end side.

[0160] According to this configuration, even if the document has a shape in which either the first corner position or the center position on the first edge side is not linear on the first edge side, it is possible to suppress a decrease in the calculation accuracy of the inclination angle of the document being conveyed, thereby improving the accuracy of stopping the conveyance of the document.

[0161] (G) In the above image reading device, when an area in the width direction that is a specified distance away from the first reference position or the second reference position is defined as a first area, the first end position and the second end position may be located in a second area that is different from the first area.

[0162] According to this configuration, the first end position and the second end position are not provided in the first region that is a specified distance away from the first reference position and the second reference position in the width direction. Therefore, even if the document has a shape in which either the first reference position or the second reference position is not linear at the first edge, the first end position and the second end position can be provided on a straight line at the first edge. This prevents a decrease in the accuracy of calculation of the inclination angle of the document being transported. Therefore, the accuracy of stopping the transport of the document can be improved.

[0163] (H) In the image reading device, the specified distance may be 5 mm or less. According to this configuration, the first end position and the second end position are not provided in the first region that is 5 mm or less in the width direction from the first reference position and the second reference position. Therefore, even if the document shape is such that either the first reference position or the second reference position is not linear at the first edge, the first end position and the second end position can be provided on a straight line at the first edge. This prevents a decrease in the accuracy of calculation of the inclination angle of the document being transported. Therefore, the accuracy of stopping the transport of the document can be improved.

[0164] (I) In the image reading device, the control unit may execute the first edge position acquisition process and the second edge position acquisition process when the width of the document in the width direction is 50 mm or more and 90 mm or less.

[0165] With this configuration, if the width of the document in the width direction is between 50 mm and 90 mm, it can be assumed that the document is receipt paper. This prevents a decrease in the accuracy of calculation of the inclination angle of the document being transported, even if there are partial cut marks on the receipt paper. This improves the accuracy of stopping the transport of the document.

[0166] (J) In the image reading device, when the control unit executes the first end position acquisition process and the second end position acquisition process and then executes the transport stop process, the control unit may execute a notification process regarding rereading of the document.

[0167] According to this configuration, when the transport of the document is stopped, a notification process regarding the re-reading of the document can be executed, thereby urging the user to re-read the document, thereby improving user convenience.

[0168] (K) A control method for an image reading device includes, when a direction intersecting a conveying direction in which a document is conveyed is defined as a width direction, acquiring from an image read from the document a first end position that is between a first reference position and a second reference position that is included in a first end side of a plurality of end sides of a document area that is closer to the conveying direction and that is included in the first end side, acquiring from the image read from the document a second end position that is between the first reference position and the second reference position, that is included in the first end side, and that is different from the first end position, and when both the first end position and the second end position are on the opposite side of the conveying direction from a first straight line that passes through the first reference position and the second reference position, stopping conveyance of the document when an inclination angle of the second straight line that passes through the first end position and the second end position with respect to the width direction exceeds a specified angle. This configuration can achieve an effect similar to that of (A).

[0169] (L) The program causes one or more computers to execute the following when a direction intersecting the conveying direction in which the document is conveyed is defined as a width direction: acquire, from an image read from the document, a first end position that is between a first reference position and a second reference position that is included in a first end side among multiple end sides of the document area on the conveying direction side and that is included in the first end side; acquire, from the image read from the document, a second end position that is between the first reference position and the second reference position, is included in the first end side and is different from the first end position; and, when both the first end position and the second end position are on the opposite side of the conveying direction from a first straight line that passes through the first reference position and the second reference position, stop conveyance of the document when an inclination angle of the second straight line that passes through the first end position and the second end position with respect to the width direction exceeds a specified angle. This configuration can achieve an effect similar to that of (A). [Explanation of symbols]

[0170] 11...image reading device, 12...casing, 13...support section, 14...supply port, 15...discharge port, 16...conveying path, 17...discharge tray, 19...placing section, 20...first document detection section, 21...feeding section, 22...reading section, 24...feeding roller, 25...separating section, 26...conveying section, 27...first roller pair, 28...second roller pair, 29...rotation detection section, 30...second document detection section, 31...light source, 32...image sensor, 33...background plate, 40...operation unit, 41...display unit, 42...control unit, 50...image area, 50A...image edge, 51...first image edge, 52...second image edge, 53...third image edge, 54...original area, 54A...edge, 55...non-original area, 56...first edge, 57...second edge, 58...third edge, 59A...partial cut mark, 59B...partial cut mark Dot mark, 61...first reference position, 62...second reference position, 63...third reference position, 64...fourth reference position, 65...fifth reference position, 69...first straight line, 71...first end position, 72...second end position, 79...second straight line, D1...conveying direction, d1...first angle, D2...scanning direction, d2...second angle, L1...first distance, L10...specified distance, L11...first specified distance, L12...second specified Distance, L2...second distance, L3...third distance, L4...fourth distance, L5...fifth distance, L6...sixth distance, L7...seventh distance, L8...eighth distance, M...original, R1...prohibited area, R11...first prohibited area, R12...second prohibited area, R2...allowed area, W...original width, X...width direction, X1...first width direction, X2...second width direction, Y...height direction, Y1...first height direction, Y2...second height direction.

Claims

1. a conveying unit that conveys the document in a conveying direction; a reading unit that reads an image from the document conveyed by the conveying unit; a control unit that controls the transport unit and the reading unit, When the direction intersecting the conveying direction is defined as the width direction, The control unit a first edge position acquisition process for acquiring, from the image read by the reading unit, a first edge position that is between a first reference position and a second reference position included in a first edge of a plurality of edges of a document area on the transport direction side and that is included in the first edge; a second end position acquisition process for acquiring, from the image read by the reading unit, a second end position that is between the first reference position and the second reference position, is included in the first end side, and is different from the first end position; and executing a transport stop process for stopping transport of the document when an inclination angle of a second straight line passing through the first end position and the second end position with respect to the width direction exceeds a specified angle, in a case where both the first end position and the second end position are on the opposite side of the transport direction from a first straight line passing through the first reference position and the second reference position. An image reading device characterized by:

2. 2. The image reading device according to claim 1, the first end position acquisition process includes a process of acquiring, as the first end position, a position that is included in the first end side and that is separated by a first distance from the first reference position toward the second reference position in the width direction, the second end position acquisition process includes a process of acquiring, as the second end position, a position that is included in the first end side and that is away from the first reference position toward the second reference position in the width direction by a second distance that is longer than the first distance, The control unit a third reference position acquisition process for acquiring, from the image read by the reading unit, a position that is included in the first straight line and is separated from the first reference position toward the second reference position in the width direction by the first distance as a third reference position; a fourth reference position acquisition process for acquiring, from the image read by the reading unit, a position that is included in the first straight line and is separated from the first reference position by the second distance toward the second reference position in the width direction, as a fourth reference position; When the image edge on the conveying direction side of the image read by the reading unit is defined as a first image edge, the transport stop process includes a process of stopping transport of the document when the first end position is on the opposite side of the transport direction from the third reference position and the second end position is on the opposite side of the transport direction from the fourth reference position, and an inclination angle of the second straight line with respect to the width direction exceeds a specified angle. An image reading device characterized by:

3. 2. The image reading device according to claim 1, the first end position acquisition process includes a process of acquiring, as the first end position, a position that is included in the first end side and that is separated by a first distance from the first reference position toward the document area in the width direction, the second end position acquisition process includes a process of acquiring, as the second end position, a position that is included in the first end side and that is separated from the first reference position in the width direction toward the document area by a second distance that is longer than the first distance, When the image edge on the conveying direction side of the image read by the reading unit is defined as a first image edge, the transport stop process includes a process of stopping transport of the document when an inclination angle of the second straight line with respect to the width direction exceeds a specified angle in a case where either the first reference position or the second reference position is located closer to the transport direction than the second straight line. An image reading device characterized by:

4. In the image reading device according to any one of claims 1 to 3, a combination of the first reference position and the second reference position is a combination of two vertices on the first end side; An image reading device characterized by:

5. 5. The image reading device according to claim 4, the combination of the first reference position and the second reference position includes a combination of a first corner position of the first end side and a second corner position of the first end side; An image reading device characterized by:

6. 5. The image reading apparatus according to claim 4, the combination of the first reference position and the second reference position includes a combination of a first corner position of the first end side and a central position of the first end side; An image reading device characterized by:

7. In the image reading device according to any one of claims 1 to 3, When a region that is a specified distance away from the first reference position or the second reference position in the width direction is defined as a first region, the first end position and the second end position are located in a second region different from the first region; An image reading device characterized by:

8. 8. The image reading device according to claim 7, The specified distance is 5 mm or less. An image reading device characterized by:

9. In the image reading device according to any one of claims 1 to 3, the control unit executes the first end position acquisition process and the second end position acquisition process when the width of the document in the width direction is equal to or greater than 50 mm and equal to or less than 90 mm. An image reading device characterized by:

10. In the image reading device according to any one of claims 1 to 3, when the control unit executes the transport stop process as a result of executing the first end position acquisition process and the second end position acquisition process, it executes a notification process related to rereading of the document. An image reading device characterized by:

11. If the direction that intersects with the document transport direction is the width direction, acquiring, from an image read from the document, a first end position that is between a first reference position and a second reference position included in a first end side on the transport direction side of a plurality of end sides of a document area and that is included in the first end side; acquiring, from an image read from a document, a second end position that is between the first reference position and the second reference position, that is included in the first end side, and that is different from the first end position; and when both the first end position and the second end position are on the opposite side of the conveying direction from a first straight line passing through the first reference position and the second reference position, stopping conveyance of the document when an inclination angle of a second straight line passing through the first end position and the second end position with respect to the width direction exceeds a specified angle.

2. A method for controlling an image reading device, comprising:

12. If the direction that intersects with the document transport direction is the width direction, On one or more computers, acquiring, from an image read from the document, a first end position that is between a first reference position and a second reference position included in a first end side on the transport direction side of a plurality of end sides of a document area and that is included in the first end side; acquiring, from an image read from a document, a second end position that is between the first reference position and the second reference position, that is included in the first end side, and that is different from the first end position; and when both the first end position and the second end position are on the opposite side of the conveying direction from a first straight line passing through the first reference position and the second reference position, stopping conveyance of the document when an inclination angle of a second straight line passing through the first end position and the second end position with respect to the width direction exceeds a specified angle. A program characterized by:

Images