Medium conveying device, control method, and control program

Abstract

To detect a bound medium more properly.SOLUTION: A medium conveying device comprises: a placing table with a medium placing surface; a pick roller for feeding a medium; a separation roller which is arranged on a downstream side in a medium conveyance direction beyond the pick roller, and which separates media so as to start conveying a medium stacked on an upper side; a distance measuring part which is arranged above a medium conveyance path on an upstream side in the conveyance direction beyond the pick roller, and arranged in a first angle direction relative to the conveyance direction, and in a second angle direction relative to a direction orthogonal to the conveyance direction, using a center position of a roller nip of the pick roller on the placing surface, as a reference; a determination part which determines that a medium is a bound medium in the case that a distance measured by the distance measuring part is equal to a threshold or less; and a control part which executes abnormality processing if a medium is determined to be a bound medium. The distance measuring part measures a distance to a medium inwardly toward a predetermined measuring region.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a medium conveying device, a control method, and a control program, and more particularly to a medium conveying device, a control method, and a control program that determine whether a medium is a binding medium. [Background technology]

[0002] Media transport devices such as scanners have the function of separating and feeding multiple media. However, if stapled media are transported while the function of separating and feeding multiple media is enabled, the media may float up without being separated, which may cause transport errors such as paper jams. Media transport devices are required to detect the bound media and stop feeding the media to prevent damage to the media when a media transport error occurs.

[0003] A known sheet feeding device includes a separation / feeding unit that separates and feeds multiple overlapping sheets one by one, and an abnormality detection unit that detects abnormal sheet intake into the conveyance path (see Patent Document 1). The abnormality detection unit detects abnormal sheet intake when a light irradiated by a light emitting unit located at approximately the same position as the intake roller in the sheet conveyance direction toward the axial side of the intake roller is blocked by the sheet. The bound sheets are detected by this sheet feeding device because the light irradiated by the light emitting unit is blocked by the light irradiated by the light emitting unit when the bound sheets jump up when they are separated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-247540 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a demand for a media transport device that can more appropriately detect media to be bound.

[0006] The object of the media transport device, the control method, and the control program is to appropriately detect the media to be bound. [Means for solving the problem]

[0007] The medium conveying device according to the embodiment includes a mounting table having a medium mounting surface, a pick roller that feeds the medium, and a separator that is disposed downstream of the pick roller in the medium conveying direction and separates the medium from the media stacked above it. Department and above the transport path of the medium on the upstream side of the pick roller in the transport direction. Distributed to When the distance measured by the distance measuring unit is equal to or less than a threshold value, Detecting binding media Department and Binding media detected a control unit that executes abnormality processing when the distance measurement unit detects an abnormality, It is located outside the pick roller in the direction perpendicular to the media transport direction, and is located on the center side. Measure the distance towards the medium.

[0008] The control method according to the embodiment includes a mounting table having a mounting surface for a medium, a pick roller for feeding the medium, and a separation roller disposed downstream of the pick roller in the conveying direction of the medium and separating the medium from the media stacked above. Department and above the transport path of the medium on the upstream side of the pick roller in the transport direction. Distributed to a distance measuring unit disposed in the medium conveying device, and when the distance measured by the distance measuring unit is equal to or less than a threshold value, Detect binding media death, Binding media detected When the abnormality is detected, the distance measuring unit executes an abnormality process. It is located outside the pick roller in the direction perpendicular to the media transport direction, and is located on the center side. Measure the distance towards the medium.

[0009] The control program according to the embodiment includes a mounting table having a mounting surface for a medium, a pick roller for feeding the medium, and a separator arranged downstream of the pick roller in the medium transport direction and separating the medium from the media stacked above it so as to transport the medium. Department and above the transport path of the medium on the upstream side of the pick roller in the transport direction. Distributed toa distance measuring unit disposed in the medium conveying device, the distance measuring unit being configured to measure a distance equal to or less than a threshold value; Detect binding media death, Binding media detected When the error is detected, the medium conveying device executes an abnormality process. It is located outside the pick roller in the direction perpendicular to the media transport direction, and is located on the center side. Measure the distance towards the medium. [Effects of the Invention]

[0010] The medium transport device, the control method, and the control program enable appropriate detection of the medium to be bound.

[0011] The objects and advantages of the invention will be realized and obtained by means of the elements and combinations particularly pointed out in the claims. Both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention as claimed. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view of a medium conveying device 100 according to an embodiment. [Figure 2] 2 is a diagram illustrating a medium transport path in the medium transport device 100. FIG. [Figure 3] 10 is a diagram for explaining an example of the arrangement of a distance measurement sensor 112. FIG. [Figure 4] FIG. 2 is a diagram for explaining a measurement region T. [Figure 5] FIG. 10 is a diagram for explaining a leading-end bound medium. [Figure 6] FIG. 10 is a diagram illustrating a state in which a leading-edge bound medium is conveyed. [Figure 7] FIG. 10 is a diagram for explaining a trailing-end binding medium. [Figure 8] FIG. 10 is a diagram illustrating a state in which a trailing-end-stitched medium is conveyed. [Figure 9] 10A and 10B are diagrams for explaining detection of a medium with a curled side edge; [Figure 10]FIG. 10 is a diagram for explaining the arrangement of a distance measurement sensor 112. [Figure 11] FIG. 10 is a diagram for explaining the arrangement of a distance measurement sensor 112. [Figure 12] 1 is a block diagram showing an example of a schematic configuration of a medium conveying device 100. FIG. [Figure 13] 1 is a block diagram showing an example of a schematic configuration of a storage device 140 and a processing circuit 150. FIG. [Figure 14] FIG. 10 is a flowchart showing an example of the operation of a medium reading process. [Figure 15] FIG. 10 is a diagram illustrating a state in which a trailing-end-stitched medium is conveyed. [Figure 16] FIG. 10 is a flowchart showing an example of the operation of a determination process. [Figure 17] FIG. 2 is a block diagram showing an example of a schematic configuration of a processing circuit 250. DETAILED DESCRIPTION OF THE INVENTION

[0013] A medium conveying device, a control method, and a control program according to one aspect of the present invention will be described below with reference to the drawings. However, please note that the technical scope of the present invention is not limited to the embodiments, but extends to the inventions set forth in the claims and their equivalents.

[0014] FIG. 1 is a perspective view showing a medium conveying device 100 configured as an image scanner. The medium conveying device 100 conveys and captures an image of a medium, which is an original document. The medium is paper, cardboard, or the like. The medium also includes bound media, which are multiple media bound together with a binding device such as staples, string, or clips. The medium conveying device 100 may be a facsimile, a copier, a multifunction printer (MFP), or the like. The medium conveying device 100 may also be a printer, in which case the conveyed medium is a print object, or the like.

[0015] The medium conveying device 100 includes a first housing 101, a second housing 102, a loading table 103, an ejection table 104, an operation device 105, a display device 106, and the like.

[0016] The first housing 101 is disposed above the medium conveying device 100 and is engaged with the second housing 102 by a hinge so that it can be opened and closed when a medium is jammed or when the inside of the medium conveying device 100 is to be cleaned.

[0017] The placement table 103 engages with the second housing 102 so that the media to be transported can be placed thereon. The placement table 103 has a media placement surface 103a, and a pair of side guides 103b are provided on the placement surface 103a. Each side guide 103b has a predetermined height in the height direction A1 and regulates the width direction of the media placed on the placement table 103. The placement table 103 is provided on the side of the second housing 102 on the media supply side and is movable in the approximately vertical direction (height direction) A1 by a motor (not shown). The placement table 103 is located at the bottom end position so that media can be easily placed on it when not transporting media, and when transporting media, it rises to a position where the uppermost medium placed on it will contact a pick roller (described later). The discharge table 104 is formed on the first housing 101 so that it can hold discharged media and stacks the discharged media.

[0018] The operation device 105 has input devices such as buttons and an interface circuit for acquiring signals from the input devices, accepts input operations by a user, and outputs operation signals in response to the user's input operations. The display device 106 has a display such as a liquid crystal display, an organic EL (Electro-Luminescence) display, or the like, and an interface circuit for outputting image data to the display, and displays the image data on the display.

[0019] 1, arrow A2 indicates the medium transport direction, arrow A3 indicates the medium discharge direction, and arrow A4 indicates the width direction perpendicular to the medium transport direction. In the following, "upstream" refers to the upstream side of the medium transport direction A2 or the medium discharge direction A3, and "downstream" refers to the downstream side of the medium transport direction A2 or the medium discharge direction A3.

[0020] 2 is a diagram illustrating the transport path inside medium transport device 100. The transport path inside medium transport device 100 includes a first medium sensor 111, multiple distance measurement sensors 112, a pick roller 113, a feed roller 114, a brake roller 115, a second medium sensor 116, first to eighth transport rollers 117a-h, first to eighth driven rollers 118a-h, a first imaging device 119a, and a second imaging device 119b. Hereinafter, first imaging device 119a and second imaging device 119b may be collectively referred to as imaging device 119.

[0021] The number of each of the pick roller 113, feed roller 114, brake roller 115, first to eighth conveyance rollers 117a-h, and / or first to eighth driven rollers 118a-h is not limited to one, and may be multiple. In this case, the multiple pick rollers 113, feed roller 114, brake roller 115, first to eighth conveyance rollers 117a-h, and / or first to eighth driven rollers 118a-h are arranged at intervals in the width direction A4. Below, an example will be described in which the medium conveying device 100 has two pick rollers 113 and two feed rollers 114.

[0022] The surface of first housing 101 facing second housing 102 forms first guide 101a of the medium transport path, and the surface of second housing 102 facing first housing 101 forms second guide 102a of the medium transport path.

[0023] The first media sensor 111 is disposed on the mounting table 103, that is, upstream of the feed roller 114 and the brake roller 115, and detects the state of the medium on the mounting table 103. The first media sensor 111 determines whether or not a medium is placed on the mounting table 103 by using a contact detection sensor that passes a predetermined current when the medium is in contact with the mounting table 103 or when the medium is not in contact with the mounting table 103. The first media sensor 111 generates and outputs a first media signal whose signal value changes depending on whether or not a medium is placed on the mounting table 103. Note that the first media sensor 111 is not limited to a contact detection sensor, and any other sensor capable of detecting the presence or absence of a medium, such as an optical detection sensor, may be used as the first media sensor 111.

[0024] The distance measuring sensors 112 are an example of a distance measuring unit and are used to detect lifting of the transported medium. The distance measuring sensors 112 are arranged on the front surface of the first housing 101, i.e., above the transport path of the medium upstream of the pick roller 113, and measure the distance to the medium. The distance measuring sensors 112 are arranged on a slope 101c extending from the lower end in the height direction A1 of the front wall 101b provided on the upstream side of the first housing 101 to connect the front wall 101b and the first guide 101a. The distance measuring sensors 112 include a light emitting element, a light receiving element, and an output circuit. The light emitting element is, for example, an LED (Light Emitting Diode) and emits light such as infrared light toward the transported medium. The light receiving element is, for example, a photodiode and detects light emitted from the light emitting element and reflected by the medium. The output circuit outputs a distance measurement signal indicating the distance from the distance measuring sensor 112 to the medium based on the time between when the light emitting element emits light and when the light receiving element detects the light.

[0025] Pick roller 113 is provided in first housing 101, and comes into contact with a medium placed on mounting table 103 raised to approximately the same height as the medium transport path, and feeds the medium downstream.

[0026] The feed roller 114 is provided inside the first housing 101 downstream of the pick roller 113, and feeds the media fed by the pick roller 113 further downstream. The brake roller 115 is provided inside the second housing 102 facing the feed roller 114. The feed roller 114 and the brake roller 115 are examples of separation rollers, and perform a media separation operation, separating the media and feeding them one by one. The feed roller 114 is provided above the brake roller 115, and the feed roller 114 and the brake roller 115 feed the media by separating the media so as to transport them from the media stacked above, a so-called top-down method.

[0027] The second medium sensor 116 is located downstream of the feed roller 114 and the brake roller 115. The second medium sensor 116 detects whether or not a medium is present at that position. The second medium sensor 116 is a regression prism sensor, and includes a light-emitting element, a light-receiving element, and a light-guiding member.

[0028] The light-emitting element and the light-receiving element are disposed outside the medium transport path, sandwiching the second guide 102a. The light-guiding member is a light guide tube such as a U-shaped prism, and is disposed outside the medium transport path, sandwiching the first guide 101a, with both ends facing the light-emitting element and the light-receiving element, respectively. The light-emitting element is an LED or the like, and emits light toward the light-guiding member, sandwiching the medium transport path. The light-receiving element receives light emitted from the light-emitting element and guided by the light-guiding member. The light-receiving element generates and outputs a second medium signal, which is an electrical signal corresponding to the intensity of the received light. When a medium is present at the position of the second medium sensor 116, the light emitted from the light-emitting element is blocked by the medium, and therefore the signal value of the second medium signal changes depending on whether a medium is present or not at the position of the second medium sensor 116.

[0029] The configuration of second medium sensor 116 is not limited to the above example. For example, a reflective member such as a mirror may be used instead of the light-guiding member. Second medium sensor 116 may also be composed of only a light-emitting element and a light-receiving element. In this case, the light-emitting element and the light-receiving element are respectively arranged in first housing 101 and second housing 102 so as to face each other across the medium transport path. Second medium sensor 116 may also be a contact detection sensor similar to first medium sensor 111.

[0030] The first to eighth conveying rollers 117a-h and the first to eighth driven rollers 118a-h are provided downstream of the feed roller 114 and the brake roller 115, and convey the medium fed by the feed roller 114 and the brake roller 115 downstream. The first to eighth conveying rollers 117a-h and the first to eighth driven rollers 118a-h are arranged opposite each other with the medium conveying path in between.

[0031] The first imaging device 119a is provided downstream of the first and second transport rollers 117a-b and the first and second driven rollers 118a-b in the medium transport direction A2. The first imaging device 119a has a line sensor based on a CIS (Contact Image Sensor) of a 1:1 optical system type having CMOS (Complementary Metal Oxide Semiconductor) imaging elements arranged linearly in the main scanning direction. The first imaging device 119a has a lens that forms an image on the imaging element and an A / D converter that amplifies and analog-to-digital (A / D) converts the electrical signal output from the imaging element. The first imaging device 119a captures an image of the surface of the medium being transported, generates an input image, and outputs it.

[0032] The second imaging device 119b is disposed downstream of the first and second transport rollers 117a-b and the first and second driven rollers 118a-b in the medium transport direction A2. The second imaging device 119b has a line sensor based on a CIS (Contact Image Sensor) of a 1:1 optical system type having CMOS (Complementary Metal Oxide Semiconductor) imaging elements arranged linearly in the main scanning direction. The second imaging device 119b has a lens that forms an image on the imaging element and an A / D converter that amplifies and analog-to-digital (A / D) converts the electrical signal output from the imaging element. The second imaging device 119b captures an image of the back side of the medium being transported, generates an input image, and outputs it.

[0033] The medium conveying device 100 may be provided with only one of the first and second imaging devices 119a and 119b, and may read only one side of the medium. Also, instead of a CIS line sensor with an equal-magnification optical system and a CMOS imaging element, a CIS line sensor with an equal-magnification optical system and a CCD (Charge Coupled Device) imaging element may be used. Also, a reduction optical system type line sensor with a CMOS or CCD imaging element may be used.

[0034] The medium placed on the mounting table 103 is transported between the first guide 101a and the second guide 102a in the medium transport direction A2 by the rotation of the pick roller 113 and the feed roller 114 in the medium feed directions A11 and A12, respectively. Meanwhile, when multiple media are placed on the mounting table 103, the brake roller 115 rotates in the direction A13 opposite to the medium transport direction, so that only the media in contact with the feed roller 114 are separated from the media placed on the mounting table 103.

[0035] The medium is guided by the first guide 101a and the second guide 102a and fed to the imaging position of the imaging device 119 by the rotation of the first and second transport rollers 117a-b in the directions of arrows A14-A15, and is imaged by the imaging device 119. The medium is then ejected onto the ejection tray 104 by the rotation of the third to eighth transport rollers 117c-h in the directions of arrows A16-A21, respectively. The ejection tray 104 holds the media ejected by the eighth transport roller 117h.

[0036] 3A and 3B are diagrams for explaining an example of the arrangement of the distance measurement sensor 112. Fig. 3A is a schematic diagram of the distance measurement sensor 112 and its surroundings as viewed from the side, and Fig. 3B is a schematic diagram of the distance measurement sensor 112 and its surroundings as viewed from the upstream side.

[0037] In the example shown in FIGS. 3A and 3B, four distance measuring sensors 112 are arranged side by side at intervals in the width direction A4. Each distance measuring sensor 112 is arranged on the inclined surface 101c of the first housing 101 at a predetermined height from the mounting surface 103a of the mounting table 103. As shown in FIG. 3A, each distance measuring sensor 112 is arranged upstream of the center position C of the roller nip of the pick roller 113 on the mounting surface 103a in the medium conveying direction A2, tilted so as to irradiate light downstream. The pick roller center C is equidistant from the two pick rollers 113 in the width direction A4 and is a position on the mounting surface that corresponds to the center of the roller nip of the pick roller 113 in the medium conveying direction A2. When the media conveying device 100 has only one pick roller 113, the pick roller center C corresponds to the center of the pick roller 113 in the width direction A4 and is a position on the loading surface that corresponds to the center of the roller nip of the pick roller 113 in the media conveying direction A2.

[0038] As shown in FIG. 3B, each distance measuring sensor 112 is disposed on the outer side of the pick roller 113 in the width direction A4, and is tilted so as to irradiate light toward the center.

[0039] As shown in Figures 3(A) and (B), each distance measuring sensor 112 is positioned to irradiate light toward a point (hereinafter sometimes referred to as a measurement point) within the measurement area T on the placement surface 103a and the second guide 102a.

[0040] FIG. 4 is a diagram for explaining the measurement region T, and is a schematic diagram of the placement surface 103a and the second guide 102a as viewed from above.

[0041] As shown in FIG. 4 , the measurement area T is a rectangular area. The measurement area T is set in an area in the width direction A4 that is outboard of the pick roller 113 and the brake roller 115 and within a predetermined distance B from the center C of the pick roller. The pick roller 113 is positioned inboard of the width of the smallest size medium supported by the medium conveying device 100 in the width direction A4. For example, if the width of the smallest size medium supported by the medium conveying device 100 is 2 inches (50.8 mm), the pick roller 113 is positioned within 25 mm of the center C of the pick roller, and the measurement area T is set in an area that is 25 mm or more away from the center C of the pick roller. The predetermined distance B is set so that lifting of the medium can be detected when the largest size medium supported by the medium conveying device 100 is bound and conveyed. Furthermore, the predetermined distance B is preferably set so that lifting of the medium is not detected when the edges of the most commonly conveyed A4-sized medium in the width direction A4 are curved or bent. For example, if the width of the largest medium supported by the medium conveying device 100 is 12 inches (304.8 mm), the predetermined distance B is set to 1 / 4 of that width (76.2 mm). As a result, even if an area several centimeters from the edge of an A4-sized medium that is 210 mm wide is curved or bent, that area is not included in the measurement area T, and the medium conveying device 100 will not determine that the medium has lifted.

[0042] Furthermore, the measurement area T is set in the medium conveyance direction A2 from the downstream end of the roller nip 113a of the pick roller 113 to the upstream end of the roller nips 114a and 115a of the feed roller 114 and the brake roller 115. For example, the measurement area T is set in the medium conveyance direction A2 to an area at least 1.5 mm away from the center C of the pick roller and no more than 32 mm away. This allows the distance measurement sensor 112 to accurately detect medium lifting that occurs between the pick roller 113 and the separation unit, while not determining that medium lifting has occurred when a medium with a curved or bent trailing edge is conveyed. Furthermore, the pick roller 113 is positioned downstream of the downstream end of the side guide 103b. This prevents the side guide 103b from being included in the measurement area T, preventing the medium conveyance device 100 from erroneously determining that medium lifting has occurred due to the influence of the side guide 103b.

[0043] 5 is a diagram for explaining leading-edge bound media, and is a schematic diagram of leading-edge bound media being transported as seen from above. Lead-edge bound media refers to media in which multiple media are bound by a binder at the ends of their leading edges in the width direction A4 (i.e., the corners of the media).

[0044] When the leading edge of the leading edge-stitched medium passes the position of the feed roller 114, medium M1, which is stapled on the upper side and in contact with the feed roller 114, receives a force pushing it downstream at contact position D with the feed roller 114. On the other hand, medium M2, which is not in contact with the feed roller 114, receives a force pushing it upstream by the brake roller 115, and therefore medium M1 receives a force pushing it upstream at binding position S. As a result, as shown in FIG. 5, the medium bends in the area surrounding the binding position S of medium M1, causing the medium to float upward, E.

[0045] 6A and 6B are diagrams for explaining the detection of the leading-edge bound medium, in which Fig. 6A is a schematic diagram of the leading-edge bound medium being transported as seen from the side, and Fig. 6B is a diagram of the leading-edge bound medium being transported as seen from the upstream side.

[0046] As described above, when the leading edge of the leading edge-stitched medium passes the position of the feed roller 114, sagging occurs. As shown in FIGS. 6A and 6B, the sagging occurs generally outside the pick roller 113 and the feed roller 114 in the width direction A4, and in the region from the downstream side of the roller nip 113a of the pick roller 113 to the upstream side of the roller nips 114a and 115a of the feed roller 114 and the brake roller 115 in the medium conveying direction A2. That is, the sagging of the leading edge-stitched medium occurs in the measurement region T of the distance measuring sensor 112. When the sagging of the medium occurs, the distance between the medium and the distance measuring sensor 112 becomes shorter. Therefore, the distance measuring sensor 112 can accurately detect the occurrence of sagging of the leading edge-stitched medium by irradiating light toward the measurement region T and measuring the distance to the medium.

[0047] 7 is a diagram for explaining a trailing-end-bound medium, and is a perspective view of a trailing-end-bound medium being conveyed. A trailing-end-bound medium is a medium in which a plurality of media are bound at their trailing ends by a binder.

[0048] When the leading edge of the trailing edge binding medium passes the position of the feed roller 114, the medium M3 that is bound on the upper side and in contact with the feed roller 114 (hereinafter referred to as the upper medium) is subjected to a force pushing it downstream at the contact position D with the feed roller 114. On the other hand, the medium M4 that is not in contact with the feed roller 114 (hereinafter referred to as the lower medium) is subjected to a force pushing it upstream by the brake roller 115, and is also subjected to a force pulling it downstream from the upper medium M3 at the binding position S. As a result, as shown in FIG. 7, the lower medium M4 is bent, and curling F occurs at the trailing edge.

[0049] 8 is a diagram for explaining detection of a trailing-end-bound medium, and is a diagram of a trailing-end-bound medium being conveyed as seen from the side.

[0050] As described above, when the trailing-end-stitched medium passes the position of the feed roller 114, curling occurs. As shown in FIG. 8 , due to curling, the trailing end of the bound medium is pulled to a position between the distance measuring sensor 112 and the measurement area T, wrapping around above the pick roller 113. Therefore, when curling of the trailing end of the medium occurs, the distance between the medium and the distance measuring sensor 112 becomes shorter. The distance measuring sensor 112 can effectively detect that curling of the trailing-end-stitched medium has occurred by irradiating light toward the measurement area T and measuring the distance to the medium.

[0051] That is, the distance measuring sensor 112 is positioned upward, upstream and outward of the pick roller 113, and tilted so as to irradiate light downstream, thereby enabling good detection of both the bending of the leading edge binding medium and the curling up of the trailing edge binding medium.

[0052] Note that the trailing-end-bound medium may be bound at the end of the trailing end in the width direction A4 (i.e., at a corner of the medium). In this case, curling occurs around the binding position of the trailing end of the medium, so the distance measurement sensor 112 can easily detect curling of the medium.

[0053] 9 is a diagram for explaining the detection of a side edge curled medium. A side edge curled medium is a medium whose edge in the width direction A4 of the medium is curved or bent upward.

[0054] The first guide 101a and the second guide 102a prevent the side edge curl medium from lifting, allowing the side edge curl medium to be transported smoothly. Therefore, it is preferable that the system not determine that the medium has lifted when the side edge curl medium is being transported. As shown in FIG. 9 , when the side edge curl medium is being transported, the center of the medium in the width direction A4 is pressed by the pick roller 113, causing only the edges in the width direction A4 to lift. If the distance measuring sensor 112 is not tilted in the width direction A4 and irradiates light vertically downward, the distance measuring sensor 112 will detect the medium lifting even when the side edge curl medium is being transported unless it is positioned inside the area where the side edge curl medium lifting occurs. On the other hand, if the distance measuring sensor 112 is positioned outside the area where the side edge curl medium lifting occurs, it may not be able to detect the above-described sagging of the leading edge bound medium and the curling of the trailing edge bound medium. The distance measuring sensor 112 is positioned outside the pick roller 113 and tilted so that it irradiates light toward the center, making it possible to effectively detect bending of the leading edge binding medium and curling of the trailing edge binding medium, while not detecting lifting of the side edge curl medium.

[0055] FIG. 10 is a diagram for explaining the arrangement of the distance measurement sensor 112. As shown in FIG.

[0056] Fig. 10(A) is a side view of the periphery of the mounting table 103. In Fig. 10(A), arrangement positions L1 to L5 indicate examples of arrangement positions of the distance measurement sensor 112. Trajectories T1 to T4 indicate trajectories along which the trailing end of A3, A4, A5, and A6 sized trailing end bound media passes when they are transported.

[0057] FIG. 10(B) is a table showing values for each of the placement positions L1 to L5. In FIG. 10(B), height H is the distance in the height direction A1 from the placement surface 103a and the second guide 102a to the distance measuring sensor 112. Angle θ1 is the angle of the position where the distance measuring sensor 112 is placed relative to the medium conveying direction A2, with the pick roller center C as the reference. Measurement point P1 is a point within the measurement area T to which the distance measuring sensor 112 irradiates light. The column for measurement point P1 in FIG. 10(B) shows the distance from the pick roller center C to the measurement point P1 in the medium conveying direction A2. Illumination distance Y is the distance from the distance measuring sensor 112 to the measurement point P1. Note that in FIG. 10(A), height H, angle θ1, measurement point P1, and illumination distance Y respectively represent height H, angle θ1, measurement point P1, and illumination distance Y for placement position L2.

[0058] The maximum value H of the height H of the distance measuring sensor 112 MAX is set based on the illumination performance of the distance measurement sensor 112. Generally, a distance measurement sensor that measures distance using light can measure distances up to a distance of 120 mm with high accuracy, but the measurement accuracy decreases when the distance exceeds 120 mm. Therefore, the maximum value H of the height H of the distance measurement sensor 112 is set to MAX is set to 120 mm (see placement position L1).

[0059] The minimum value H of the height H of the distance measuring sensor 112 MIN is set based on the trajectories T1 to T4 of the trailing end of the trailing end bound medium when it is transported. Among the trajectories T1 to T4 of the trailing end bound medium of A3, A4, A5, and A6 sizes around the pick roller 113, the trajectory T2 of the trailing end bound medium of A4 size passes through the highest position. If the height H of the distance measuring sensor 112 is lower than 54 mm, the trajectory T2 of the trailing end bound medium of A4 size will overlap with the distance measuring sensor 112. In this case, the trailing end of the trailing end bound medium of A4 size may collide with the distance measuring sensor 112, and the distance measuring sensor 112 may not be able to properly detect the distance to the medium. Therefore, the minimum value H of the height H of the distance measuring sensor 112 MIN is set to 54 mm (see location L5).

[0060] Therefore, the distance measuring sensor 112 is disposed at a height of 54 mm or more and 120 mm or less from the placement surface 103a, so that the distance measuring sensor 112 can properly detect the trailing end of the trailing-end-bound medium.

[0061] The maximum value of the angle θ1 of the distance measuring sensor 112 is set based on the trajectory T1 to T4 of the trailing end of the trailing end bound medium when it is transported. If the angle θ1 of the distance measuring sensor 112 is greater than 86°, a straight line passing through the distance measuring sensor 112 and the measurement point P1 does not intersect with the trajectory T1 to T4 of the trailing end bound medium. In this case, the trailing end of the trailing end bound medium does not reach the range measured by the distance measuring sensor 112, and the distance measuring sensor 112 may not be able to detect the trailing end of the trailing end bound medium. Therefore, the maximum value of the angle θ1 of the distance measuring sensor 112 is set to 86° (see arrangement position L1).

[0062] The minimum value of the angle θ1 of the distance measurement sensor 112 is set based on the illumination performance of the distance measurement sensor 112 and the trajectories T1 to T4 of the trailing edge of the trailing edge bound medium when it is transported. Even if the illumination distance Y between the distance measurement sensor 112 and the measurement point P1 is 120 mm, which is the upper limit distance of the illumination performance of the distance measurement sensor 112, if the angle θ1 of the distance measurement sensor 112 is smaller than 59°, the trajectory T2 of the A4-sized trailing edge bound medium will overlap with the distance measurement sensor 112. In this case, the trailing edge of the A4-sized trailing edge bound medium may collide with the distance measurement sensor 112, which may prevent the distance measurement sensor 112 from properly detecting the distance to the medium. Therefore, the minimum value of the angle θ1 of the distance measurement sensor 112 is set to 59° (see arrangement position L2).

[0063] Therefore, the distance measurement sensor 112 is disposed at an angle θ1 with respect to the conveying direction A2, with the center C of the pick roller as the reference. Disposing the distance measurement sensor 112 at an angle θ1 with respect to the medium conveying direction A2, with the center C of the pick roller as the reference, means that the angle formed by the line connecting the center C of the pick roller and the center position of the light-emitting position and light-receiving position of the distance measurement sensor 112, and the medium conveying direction A2 is θ1. The angle θ1 is an example of a first angle. The angle θ1 is greater than or equal to 59 degrees and less than or equal to 86 degrees. This allows the distance measurement sensor 112 to accurately detect the trailing edge of trailing-edge-bound media of various sizes.

[0064] FIG. 11 is a diagram for explaining the arrangement of the distance measurement sensor 112. As shown in FIG.

[0065] 11A is a view of the periphery of the mounting table 103 as seen from the upstream side. In FIG. 11A, arrangement positions L6 to L9 indicate examples of arrangement positions of the distance measuring sensors 112.

[0066] FIG. 11B is a table showing values for each of the placement positions L6 to L9. In FIG. 11B, height H is the distance in the height direction A1 from the placement surface 103a and the second guide 102a to the distance measuring sensor 112. Angle θ2 is the angle of the position where the distance measuring sensor 112 is placed relative to the width direction A4, with the center C of the pick roller as the reference. Measurement point P2 is a point within the measurement area T to which the distance measuring sensor 112 irradiates light. The column for measurement point P2 in FIG. 11B shows the distance from the center C of the pick roller to the measurement point P2 in the width direction A4. Illumination distance Y is the distance from the distance measuring sensor 112 to the measurement point P2. Note that in FIG. 11A, height H, angle θ2, measurement point P2, and illumination distance Y respectively represent height H, angle θ2, measurement point P2, and illumination distance Y for placement position L9.

[0067] The maximum value of the angle θ2 of the distance measuring sensor 112 is set based on the irradiation performance of the distance measuring sensor 112 and the arrangement position of the pick roller 113. The distance measuring sensor 112 is arranged outside the pick roller 112 in the width direction A4 so that it can irradiate the outer edge of the roller nip 113a of the pick roller 113. As described above, when the pick roller 113 is arranged within 50 mm from the center C of the pick roller, the maximum value of θ2 is tan -1 The angle θ2 is set to (120 mm / 25 mm)≈78°. However, a support member (not shown) for supporting the pick roller 113 on the first housing 101 is usually provided outside the pick roller 113. It is preferable that the distance measuring sensor 112 is disposed approximately 20 mm further outward from the pick roller 113 in the width direction A4 so that the light from the distance measuring sensor 112 is not blocked by the support member of the pick roller 113. In this case, the maximum value of the angle θ2 is tan -1 It is set to (120 mm / 45 mm) ≒ 70° (see arrangement position L6).

[0068] The minimum value of the angle θ2 of the distance measuring sensor 112 is set based on the illumination performance of the distance measuring sensor 112 and the edge position of the measurement area T in the width direction A4. As described above, the measurement area T is set within a range of 76.2 mm from the center C of the pick roller so as to detect lifting of the bound medium having the maximum size supported by the medium conveying device 100 while not detecting lifting due to curvature or bending of the edge of an A4-sized medium in the width direction A4. Meanwhile, the distance from the center C of the pick roller to the edge of an A4-sized medium in the width direction A4 is 105 mm. For example, if the distance between the first guide 101a and the second guide 102a is set to 15 mm, the medium will be conveyed smoothly if the amount of lifting of the edge of the medium is 15 mm or less. However, if the amount of lifting of the edge of the medium exceeds 15 mm, the medium will collide with the front surface of the first housing 101. Therefore, it is preferable that the distance measuring sensor 112 is installed so as to detect lifting exceeding 15 mm in height at a distance of 105 mm from the center C of the pick roller, but not to detect lifting of 15 mm or less in height. If the irradiation distance Y of the distance measuring sensor 112 is 120 mm, as in the arrangement position L9 in FIG. 11, due to the similarity relationship of triangles, the distance from the end of the measurement area T to the distance measuring sensor 112 in the width direction A4 is 106.4 mm, and the height H of the distance measuring sensor 112 is 55.4 mm. Therefore, the distance from the center C of the pick roller to the distance measuring sensor 112 is 182.6 mm, and the minimum value of the angle θ2 is tan -1 It is set to (182.6 mm / 55.4 mm) ≒ 17° (see arrangement position L9).

[0069] Therefore, the distance measuring sensor 112 is disposed at an angle θ2 with respect to the width direction A4, with the center C of the pick roller as the reference. Disposing the distance measuring sensor 112 at an angle θ2 with respect to the width direction A4 with the center C of the pick roller as the reference means that the angle formed by the line connecting the center C of the pick roller and the center position of the light emitting position and light receiving position of the distance measuring sensor 112, with the width direction A4, is θ2. The angle θ2 is an example of a second angle. The angle θ2 is equal to or greater than 17 degrees and equal to or less than 70 degrees. This enables the distance measuring sensor 112 to properly detect leading-edge bound media without detecting lifting of media with side edge curls.

[0070] 12 is a diagram showing an example of a schematic configuration of the medium conveying device 100. In addition to the configuration described above, the medium conveying device 100 further includes a motor 131, an interface device 132, a storage device 140, a processing circuit 150, and the like.

[0071] The motor 131 includes one or more motors, and rotates the pick roller 113, the feed roller 114, the brake roller 115, and the first to eighth transport rollers 117a-h to feed and transport the medium in response to a control signal from the processing circuit 150. The first to eighth driven rollers 118a-h may be configured to rotate by the driving force from the motor, rather than being rotated in accordance with the rotation of the transport rollers.

[0072] The interface device 132 has an interface circuit conforming to a serial bus such as USB, and is electrically connected to an information processing device (not shown) (for example, a personal computer, a personal digital assistant, etc.) to transmit and receive scanned images and various information. Instead of the interface device 132, a communication unit having an antenna for transmitting and receiving wireless signals and a wireless communication interface circuit for transmitting and receiving signals via a wireless communication line in accordance with a predetermined communication protocol may be used. The predetermined communication protocol is, for example, a wireless LAN (Local Area Network).

[0073] The storage device 140 includes a memory device such as a RAM (Random Access Memory) or a ROM (Read Only Memory), a fixed disk device such as a hard disk, or a portable storage device such as a flexible disk or optical disk. The storage device 140 also stores computer programs, databases, tables, and the like used for various processes of the medium conveying device 100. The computer programs may be installed into the storage device 140 from a computer-readable, non-transitory portable recording medium using a known setup program or the like. The portable recording medium is, for example, a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), or the like.

[0074] The processing circuit 150 is a circuit that operates based on a program stored in advance in the storage device 140. The processing circuit 150 is, for example, a CPU (Central Processing Unit). The processing circuit 150 may be a DSP (Digital Signal Processor), an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or the like.

[0075] The processing circuit 150 is connected to the operation device 105, the display device 106, the first medium sensor 111, the distance measurement sensor 112, the second medium sensor 116, the imaging device 119, the motor 131, the interface device 132, the storage device 140, etc., and controls each of these components. The processing circuit 150 controls the motor 131 to transport the medium, controls the imaging device 119 to acquire an input image, and transmits the acquired input image to the information processing device via the interface device 132. The processing circuit 150 also determines whether the medium being transported is a binding medium based on the distance measurement signal received from the distance measurement sensor 112.

[0076] FIG. 13 is a diagram showing a schematic configuration of the storage device 140 and the processing circuit 150. As shown in FIG.

[0077] The storage device 140 stores various programs such as a control program 141 and a determination program 142. These programs are functional modules implemented by software running on a processor. The processing circuit 150 reads the programs stored in the storage device 140 and operates in accordance with the read programs, thereby functioning as a control unit 151 and a determination unit 152. Note that the control unit 151 and the determination unit 152 may each be configured as an integrated circuit, a microprocessor, firmware, or the like, independent of the processing circuit 150.

[0078] 14 is a flow diagram showing an example of the operation of a medium reading process executed by medium conveying device 100. The medium reading process is realized by processing circuitry 150 cooperating with each element of medium conveying device 100 based on a program stored in storage device 140.

[0079] First, the control unit 151 waits until it receives an operation signal instructing to read a medium (S101). The operation signal is supplied from the operation device 105 to the control unit 151 in response to a user inputting an instruction to read a medium into the operation device 105. The operation signal may be supplied from the information processing device via the interface device 132 in response to a user inputting an instruction to read into the information processing device.

[0080] Next, the control unit 151 determines whether or not a medium is placed on the placement table 103 based on the first medium signal output from the first medium sensor 111 (S102). If no medium is placed on the placement table 103 (S102-No), the control unit 151 ends the medium reading process.

[0081] If a medium is placed (S102-Yes), the determination unit 152 sets a threshold value to be compared with the distance indicated in the distance measurement signal to an initial value in order to determine whether the medium is a binding medium (S103).

[0082] Next, the control unit 151 starts feeding and transporting the medium (S104). The control unit 151 drives the motor for moving the mounting table 103, and raises the mounting table 103 to a position where the medium can be fed. The control unit 151 drives the motor 131 to rotate the pick roller 113, the feed roller 114, the brake roller 115, and the first to eighth transport rollers 117a-h, and feeds and transports the medium placed on the mounting table 103.

[0083] Next, the control unit 151 determines whether a predetermined time has elapsed since the feeding of the medium started, that is, since the motor 131 was driven to start the rotation of the pick roller 113, the feed roller 114, and the brake roller 115 (S105). As the predetermined time, one or more times greater than 0 and less than the time required for the feeding of a medium of the maximum size supported by the medium conveying device 100 to be completed are set in advance. If the predetermined time has not elapsed since the feeding of the medium started (S105-No), the control unit 151 proceeds to S107.

[0084] If a predetermined time has elapsed since feeding started (S105-Yes), the determination unit 152 changes the threshold value (S106). The medium conveying device 100 stores in the storage device 140 a value set as the threshold value at the time each predetermined time has elapsed since feeding started, for one or more predetermined times. The threshold value is changed so that it has a smaller value as the predetermined time is longer. In other words, the determination unit 152 decreases the threshold value as time passes since feeding of the medium started.

[0085] As shown in FIG. 6B, when leading-edge bound media is transported, the media bends immediately after the leading edge of the leading-edge bound media passes through the separation section. The bending occurs around the binding section, and the amount of lift of the media due to the bending is relatively small. On the other hand, as shown in FIG. 8, when trailing-edge bound media is transported, the trailing edge of the media curls up when a sufficient amount of time has passed since the leading edge of the leading-edge bound media passed through the separation section. The trailing edge of the media curls up so as to wrap around above the pick roller 113, and the amount of lift of the media due to the curling is large.

[0086] Fig. 15 is a diagram showing a state in which a trailing-end-bound medium larger than the trailing-end-bound medium shown in Fig. 8 is conveyed. Fig. 15 is a diagram of the trailing-end-bound medium being conveyed as seen from the side.

[0087] 15, with a large trailing-end-bound medium, the distance from the trailing end of the medium to the detection area of the distance measuring sensor 112 is large, so it takes a long time for the trailing end of the medium to be detected by the distance measuring sensor 112. In addition, the arc formed by the curled-up trailing-end-bound medium is larger than the arc formed by a small trailing-end-bound medium, and the trailing end of the large trailing-end-bound medium rises to a higher position than the trailing end of the small trailing-end-bound medium. Therefore, with a large trailing-end-bound medium, it takes a longer time to be detected by the distance measuring sensor 112 and the amount of lift of the medium is greater than with a small trailing-end-bound medium.

[0088] If the threshold value used to compare the distance between the medium and the distance measuring sensor 112 is large, it is more likely that a medium that is partially curved or bent will be determined to have lifted up when the medium is conveyed. In particular, if a medium with a mountain fold on the trailing edge is conveyed, it is more likely that a medium that is lifted up will be determined to have occurred. The determination unit 152 decreases the threshold value as time passes after the start of medium feeding. This allows the determination unit 152 to effectively detect medium lifting when leading-edge bound medium and trailing-edge bound medium are conveyed, while reducing the possibility of erroneously determining that the medium is a bound medium when a curved or bent medium is conveyed.

[0089] Next, the determination unit 152 executes a determination process to determine whether the medium is a binding medium (S107). Details of the determination process will be described later.

[0090] Next, the control unit 151 determines whether the medium is determined to be a binding medium in the determination process (S108). If the medium is determined to be a binding medium (S108-Yes), the control unit 151 outputs a notification that the medium is a binding medium (S109). The control unit 151 outputs the notification that the medium is a binding medium by displaying it on the display device 106, thereby notifying the user. The control unit 151 may output a notification signal indicating the notification that the medium is a binding medium by transmitting it to the information processing device via the interface device 132, thereby notifying the user. Next, the control unit 151 stops the motor 131, thereby stopping the rotation of the pick roller 113, the feed roller 114, the brake roller 115, and the first to eighth conveyance rollers 117a-h, thereby stopping the feeding and conveyance of the medium (S110), and ending the medium reading process. Note that outputting the notification that the medium is a binding medium and stopping the conveyance of the medium are examples of executing abnormality processing.

[0091] The control unit 151 can prevent the occurrence of a medium jam and damage to the medium by stopping the transport of the medium when the bound medium is transported. The control unit 151 can also prevent staples, clips, etc. that have bound the medium from entering the medium transport path and damaging the glass surface of the imaging device 119. This eliminates the need for the user to check whether the medium to be transported is stapled before transporting the medium, and the medium transport device 100 can improve user convenience and reduce the processing time for the medium reading process.

[0092] If the medium is not determined to be a binding medium (S108-No), the control unit 151 determines whether the leading edge of the medium has passed the position of the first conveyance roller 117a (S111). For example, the control unit 151 periodically acquires a second medium signal from the second medium sensor 116, and determines that the leading edge of the medium has passed the position of the second medium sensor 116 when the signal value of the second medium signal changes from a value indicating that the medium is not present to a value indicating that the medium is present. The control unit 151 determines that the leading edge of the medium has passed the position of the first conveyance roller 117a when a first time has elapsed since the leading edge of the medium passed the position of the second medium sensor 116. The first time is set to the time it takes for the medium to be conveyed from the second medium sensor 116 to the first conveyance roller 117a plus a margin. If the leading edge of the medium has not yet passed the position of the first conveyor roller 117a (S111-No), the control unit 151 returns the process to S105 and repeats the processes of S105 to S111.

[0093] If the leading edge of the medium has passed the position of first conveyor roller 117a (S111-No), control unit 151 controls motor 131 to stop the rotation of pick roller 113, feed roller 114, and brake roller 115, thereby stopping feeding of the medium (S112). As a result, the medium is subsequently conveyed by first to eighth conveyor rollers 117a-h. Note that if feeding of the medium has already stopped, the processing of S112 is omitted.

[0094] Next, the control unit 151 determines whether the trailing edge of the medium has passed the imaging position of the imaging device 119 (S113). For example, the control unit 151 periodically acquires a second medium signal from the second medium sensor 116, and determines that the trailing edge of the medium has passed the position of the second medium sensor 116 when the signal value of the second medium signal changes from a value indicating the presence of the medium to a value indicating the absence of the medium. The control unit 151 determines that the trailing edge of the medium has passed the imaging position when a second time has elapsed since the trailing edge of the medium passed the position of the second medium sensor 116. The second time is set to the time it takes for the medium to be transported from the second medium sensor 116 to the imaging position plus a margin. If the trailing edge of the medium has not yet passed the imaging position (S112-No), the control unit 151 returns to S105 and repeats the processes of S105 to S113.

[0095] When the trailing edge of the medium passes the imaging position (S113-Yes), the determination unit 152 determines that the medium is not a binding medium. That is, the determination unit 152 determines that the medium is not a binding medium if the medium is not determined to be a binding medium in the determination process until the trailing edge of the medium passes the imaging position.

[0096] Next, the control unit 151 acquires an input image from the imaging device 119. The control unit 151 transmits the acquired input image to the information processing device via the interface device 132 (S115).

[0097] Next, the control unit 151 determines whether a medium is placed on the placement table 103 based on the first medium signal output from the first medium sensor 111 (S116). If a medium is placed on the placement table 103 (S116-Yes), the control unit 151 returns the process to S103 and repeats the processes of S103 to S116. However, when the second or subsequent medium is fed, the first to eighth conveyance rollers 117a-h are already rotating. Therefore, in S104, the control unit 151 controls the motor 131 to resume the rotation of the pick roller 113, the feed roller 114, and the brake roller 115 to resume feeding of the medium. If a medium is not placed on the placement table 103 (S116-No), the control unit 151 stops the motor 131 (S110) and ends the medium reading process. In this case, since the pick roller 113, the feed roller 114, and the brake roller 115 have already stopped, the control unit 151 stops the rotation of the first to eighth conveyance rollers 117a-h, thereby stopping the conveyance of the medium.

[0098] 16 is a flow diagram showing an example of the operation of the determination process. The determination process is executed in S107 of the medium reading process.

[0099] First, the determination unit 152 acquires distance measurement signals from each distance measurement sensor 112 (S201).

[0100] Next, the determination unit 152 determines whether the distance between each distance measurement sensor 112 and the medium is equal to or less than a threshold based on the acquired distance measurement signal (S202). If it is determined that the distance between at least one distance measurement sensor 112 and the medium is equal to or less than the threshold (S202-Yes), the determination unit 152 determines that the medium is a binding medium (S203) and ends the determination process. In this way, the determination unit 152 determines that the medium is a binding medium when the distance measured by the distance measurement sensor 112 is equal to or less than the threshold.

[0101] If the distances between all the distance measuring sensors 112 and the medium are greater than the threshold value (S202-No), the determination unit 152 ends the determination process without yet determining whether the medium is a binding medium.

[0102] As described above, the medium conveying device 100 has multiple distance measuring sensors 112 that are arranged at an angle θ1 with respect to the medium conveyance direction A2 and at an angle θ2 with respect to the width direction A4, with the pick roller center C as the reference, and measure the distance to the medium toward the measurement area T. Furthermore, the medium conveying device 100 determines that the medium is a bound medium when the distance from the distance measuring sensor 112 to the medium is equal to or less than a threshold value. This enables the medium conveying device 100 to detect both leading-end bound media and trailing-end bound media, enabling it to properly detect bound media.

[0103] In addition, since the media conveying device 100 does not need to be equipped with a sensor for detecting leading-end bound media and a sensor for detecting trailing-end bound media, the manufacturing costs, implementation space, maintenance labor, etc. of the media conveying device 100 can be reduced.

[0104] In the above description, the medium conveying device 100 is described as having a plurality of distance measuring sensors 112, but it may also be configured as having only one distance measuring sensor 112. In this case, the medium conveying device 100 can also appropriately detect the binding medium.

[0105] 17 is a diagram showing a schematic configuration of a processing circuit 250 in a medium conveying device according to another embodiment. The processing circuit 250 is used in place of the processing circuit 150 of the medium conveying device 100, and executes a medium reading process. The processing circuit 250 includes a control circuit 251 and a determination circuit 252. Note that each of these components may be configured as an independent integrated circuit, microprocessor, firmware, or the like.

[0106] The control circuit 251 is an example of a control unit, and has the same functions as the control unit 151. The control circuit 251 receives an operation signal from the operation device 105, a first medium signal from the first medium sensor 111, and a determination result in the determination process from the determination circuit 252, and controls the motor 131 based on the received signals and the determination result. The control circuit 251 also receives an input image from the imaging device 119, stores it in the storage device 140, and transmits it to the information processing device via the interface device 132.

[0107] The determination circuit 252 is an example of a determination unit, and has the same function as the determination unit 152. The determination circuit 252 receives distance measurement signals from the distance measurement sensor 112. Based on each received signal, the determination circuit 252 determines whether the medium is a binding medium or not, and outputs the determination result to the control circuit 251.

[0108] As described above, the medium conveying device can appropriately detect the binding medium even when the processing circuit 250 is used.

[0109] It should be understood by those skilled in the art that various changes, substitutions, and alterations can be made to the present invention without departing from the spirit and scope of the present invention. For example, the above-described embodiments and modifications may be implemented in appropriate combinations within the scope of the present invention. [Explanation of symbols]

[0110] 100 Media transport device 103 Mounting table 112 Distance Sensor 113 Pick roller 114 Feeding roller 115 Brake roller 151 Control Unit 152 Judgment section

Claims

1. a mounting table having a mounting surface for the medium; a pick roller for feeding the medium; a separation unit disposed downstream of the pick roller in a medium transport direction, the separation unit separating the medium from the media stacked above it; a distance measuring unit disposed above a medium transport path upstream of the pick roller in the transport direction; a detection unit that detects the binding medium when the distance measured by the distance measurement unit is equal to or less than a threshold; a control unit that executes an abnormality process when a binding medium is detected; the distance measuring unit is disposed outside the pick roller in a direction perpendicular to the medium conveyance direction, and measures the distance to the medium toward the center. A medium transport device characterized by:

2. A media conveying device as described in Claim 1, wherein the distance measuring unit measures the distance to the media toward the area downstream of the roller nip of the pick roller.

3. A media conveying device as described in Claim 2, wherein the distance measuring unit measures the distance to the media from the downstream side of the roller nip of the pick roller toward the upstream area of the separation unit.

4. A medium conveying device as described in any one of claims 1 to 3, wherein the threshold value changes slightly over time after the feeding of the medium begins.

5. a center position of a light emitting position and a light receiving position of the distance measuring unit is disposed in a direction at a first angle with respect to the conveying direction, with a center position of a roller nip of the pick roller on the placement surface as a reference; The medium transport device of claim 1 , wherein the first angle is equal to or greater than 59 degrees and equal to or less than 86 degrees.

6. a center position of a light emitting position and a light receiving position of the distance measuring unit is disposed in a direction at a second angle with respect to a direction perpendicular to the conveying direction, with a center position of a roller nip of the pick roller on the placement surface as a reference; The medium transport device according to claim 1 , wherein the second angle is equal to or greater than 17 degrees and equal to or less than 70 degrees.

7. The medium transport device according to claim 1 , wherein the distance measuring unit is disposed at a height of 54 mm or more and 120 mm or less from the placement surface.

8. A control method for a medium transport device having a mounting table having a mounting surface for a medium, a pick roller that feeds the medium, a separation unit that is arranged downstream of the pick roller in a medium transport direction and separates the medium so as to be transported from media stacked above, and a distance measurement unit that is arranged above a medium transport path upstream of the pick roller in the medium transport direction, comprising: When the distance measured by the distance measuring unit is equal to or less than a threshold value, the binding medium is detected; When the binding medium is detected, an abnormality process is executed. the distance measuring unit is disposed outside the pick roller in a direction perpendicular to the medium conveyance direction, and measures the distance to the medium toward the center. A control method comprising:

9. A control program for a medium transport device having a mounting table having a mounting surface for a medium, a pick roller for feeding the medium, a separation unit arranged downstream of the pick roller in a medium transport direction and separating the medium so as to transport it from media stacked above, and a distance measurement unit arranged above a medium transport path upstream of the pick roller in the transport direction, When the distance measured by the distance measuring unit is equal to or less than a threshold value, the binding medium is detected; When the binding medium is detected, the medium conveying device executes an abnormality process; the distance measuring unit is disposed outside the pick roller in a direction perpendicular to the medium conveyance direction, and measures the distance to the medium toward the center. A control program comprising:

Images