Medium conveying device

Abstract

To provide a medium conveying device with a light emitting element and a light receiving element arranged properly.SOLUTION: A medium conveying device has: a set guide; a feed roller; conveyance rollers; a moving mechanism for moving the set guide; a guide pair which includes a first guide provided between the feed roller and the conveyance rollers in a medium conveyance direction and having a first opening and a second opening for detecting a medium fed by the feed rollers, and a second guide located to sandwich a medium conveyance path together with the first guide, and which guide pair regulates a vertical direction of the medium conveyance path; a light emitting element and a light receiving element, which are located outside the medium conveyance path across the first guide and are located on a downstream side of the first opening and the second opening to be apart from the moving mechanism by a predetermined distance or more in the medium conveyance direction; a first light guide which is bent to guide the light emitted from the light emitting element to the first opening; and a second light guide which is bent to guide the light incident from the second opening to the light receiving element.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

[0001] The present invention relates to a medium transport device, and more particularly to a medium transport device having a light emitting element and a light receiving element. [Background technology]

[0002] In a media transport device such as a scanner that transports and captures a medium, it is necessary to accurately detect the state of the medium being transported in order to appropriately control the transport of the medium. In such a media transport device, for example, a light-emitting element and a light-receiving element are provided near the medium transport path, and the medium is detected based on the intensity of light received by the light-receiving element.

[0003] An optical sensor has been disclosed that includes a sensitive part that changes the refractive index in response to a substance in a fluid, a light-emitting element that irradiates light onto the sensitive part, and a light-receiving element that receives the light reflected from the sensitive part (see Patent Document 1). This optical sensor detects substances based on changes in the light intensity of the reflected light that correspond to changes in the refractive index of the sensitive part.

[0004] A sheet edge detection device has been disclosed that includes a light-emitting unit that irradiates light onto a sheet being conveyed, and a light-receiving unit that is disposed at one edge of the sheet in a direction perpendicular to the sheet conveyance direction and receives the light from the light-emitting unit (see Patent Document 2). This sheet edge detection device detects the position of the edge based on the amount of light received by the light-receiving unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-183863 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-157448 Summary of the Invention [Problem to be solved by the invention]

[0006] Generally, a medium transport device has various components for transporting a medium, and it is necessary to appropriately arrange the light emitting element and the light receiving element.

[0007] An object of the present invention is to provide a medium transport device in which light emitting elements and light receiving elements are appropriately arranged. [Means for solving the problem]

[0008] a first guide provided between the feed roller and the conveying roller in the medium conveying direction and having a first opening and a second opening for detecting the medium fed by the feed roller; and a second guide arranged to sandwich the medium conveying path together with the first guide, and including a guide pair that regulates the up-down direction of the medium conveying path; a light-emitting element and a light-receiving element arranged outside the medium conveying path across the first guide and downstream of the first opening and the second opening so as to be separated from the moving mechanism in the medium conveying direction by a predetermined distance or more; a first light-guiding section bent to guide light emitted from the light-emitting element to the first opening; and a second light-guiding section bent to guide light incident from the second opening to the light-receiving element. [Effects of the Invention]

[0009] According to the present invention, the light emitting element and the light receiving element are appropriately arranged in the medium transport device. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a medium conveying device 100 according to an embodiment. [Figure 2] 2 is a diagram for explaining a transport path inside the medium transport device 100. FIG. [Figure 3A] 10 is a schematic diagram for explaining a set guide 112 and the like. FIG. [Figure 3B] 10 is a schematic diagram for explaining a set guide 112 and the like. FIG. [Figure 4A] 10A and 10B are schematic diagrams for explaining the operation of the set guide 112 and the like. [Figure 4B] 10A and 10B are schematic diagrams for explaining the operation of the set guide 112 and the like. [Figure 5] 10 is a schematic diagram for explaining a first sensor 117 and the like. FIG. [Figure 6] 10 is a schematic diagram for explaining the positional relationship of a first sensor 117 and the like. FIG. [Figure 7] 10 is a schematic diagram for explaining the positional relationship of a first sensor 117 and the like. FIG. [Figure 8] 10 is a schematic diagram for explaining the shape of a first sensor 117. FIG. [Figure 9A] 10 is a schematic diagram for explaining the shape of a first light guiding section 117c. FIG. [Figure 9B] 10 is a schematic diagram for explaining the shape of a second light guiding section 117d. FIG. [Figure 10A] FIG. 10 is a schematic diagram for explaining a coupling portion 117f. [Figure 10B] FIG. 10 is a schematic diagram for explaining a coupling portion 117f. [Figure 11] FIG. 2 is a schematic diagram for explaining a path of light. [Figure 12A] FIG. 10 is a schematic diagram for explaining the technical significance. [Figure 12B] FIG. 10 is a schematic diagram for explaining the technical significance. [Figure 13A] FIG. 10 is a schematic diagram for explaining the technical significance. [Figure 13B] FIG. 10 is a schematic diagram for explaining the technical significance. [Figure 14] 1 is a block diagram showing a schematic configuration of a medium conveying device 100. FIG. [Figure 15] FIG. 2 is a diagram showing a schematic configuration of a storage device 160 and a CPU 170. [Figure 16]10 is a flowchart illustrating an example of the operation of a medium reading process. [Figure 17] 10A and 10B are schematic diagrams for explaining other arrangements of light emitting elements and light receiving elements. [Figure 18] FIG. 10 is a diagram showing a schematic configuration of still another processing circuit 270. DETAILED DESCRIPTION OF THE INVENTION

[0011] A medium transport device 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.

[0012] 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 may be paper, thin paper, thick paper, a card, a booklet, a passport, or the like. The medium may also include a transparent carrier sheet that sandwiches the paper so that the paper is folded in half for conveyance or to protect the paper. The medium conveying device 100 may also be a facsimile machine, a copier, a multifunction printer (MFP), or the like. Note that the conveyed medium may not be an original document but may be a print target or the like, and the medium conveying device 100 may also be a printer or the like.

[0013] The medium conveying device 100 includes a lower housing 101, an upper housing 102, a loading tray 103, an ejection tray 104, an operation device 105, and a display device 106. In FIG. 1, arrow A1 indicates the medium conveying direction. Hereinafter, "upstream" refers to the upstream side of the medium conveying direction A1, and "downstream" refers to the downstream side of the medium conveying direction A1. Arrow A2 indicates the width direction perpendicular to the medium conveying direction A1. Arrow A3 indicates the up-down direction A3 perpendicular to the medium conveying surface.

[0014] The upper housing 102 is positioned to cover the top surface of the medium transport device 100, and is engaged with the lower housing 101 by a hinge so that it can be opened and closed when a medium becomes jammed or when cleaning the inside of the medium transport device 100. The loading platform 103 is engaged with the lower housing 101 so that the medium to be transported can be placed on it. The ejection platform 104 is engaged with the lower housing 101 so that it can hold the ejected medium.

[0015] 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.

[0016] FIG. 2 is a diagram for explaining the transport path inside the medium transport device 100. As shown in FIG.

[0017] The conveying path inside the medium conveying device 100 includes a medium sensor 111, a set guide 112, a moving mechanism 113, a flap 114, a feed roller 115, a brake roller 116, a first sensor 117, a second sensor 118, a third sensor 119, a first conveying roller 120, a second conveying roller 121, a fourth sensor 122, a first imaging device 123a, a second imaging device 123b, a third conveying roller 124, and a fourth conveying roller 125. The number of each roller is not limited to one, and there may be more than one of each roller.

[0018] The upper surface of the lower housing 101 forms a lower guide 107a of the medium transport path, and the lower surface of the upper housing 102 forms an upper guide 107b of the medium transport path. The lower guide 107a is an example of a first guide and guides the lower surface of the transported medium. The upper guide 107b is an example of a second guide and is arranged to sandwich the medium transport path together with the lower guide 107a and guide the upper surface of the transported medium. The lower guide 107a and the upper guide 107b are an example of a guide pair and regulate the vertical direction of the medium transport path. The lower guide 107a and the upper guide 107b are arranged so as to be separated by a predetermined distance or more. The predetermined distance is a length sufficient to transport a passport having a thickness of approximately 5 mm, and is set in the range of 7 mm to 20 mm. In this way, the lower guide 107a and the upper guide 107b are arranged to be able to transport a passport as a medium.

[0019] The media sensor 111 is disposed upstream of the feed roller 115 and the brake roller 116. The media sensor 111 has a contact detection sensor and detects whether or not a medium is placed on the placement table 103. The media sensor 111 generates and outputs a media signal whose signal value changes depending on whether or not a medium is placed on the placement table 103.

[0020] The feed roller 115 is provided in the lower housing 101, and feeds the media placed on the mounting table 103 and set in the set guide 112 in order from the bottom up. The brake roller 116 is provided in the upper housing 102, and is disposed opposite the feed roller 115.

[0021] The first conveying roller 120 and the second conveying roller 121 are provided downstream of the feed roller 115 and the brake roller 116 and upstream of the first imaging device 123a and the second imaging device 123b in the medium conveying direction A1. The first conveying roller 120 is provided in the lower housing 101, and the second conveying roller 121 is provided in the upper housing 102 opposite the first conveying roller 120. The first conveying roller 120 and the second conveying roller 121 convey the medium fed by the feed roller 115 downstream, i.e., to the first imaging device 123a and the second imaging device 123b.

[0022] The first imaging device 123a 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 123a also 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 123a generates and outputs an input image by capturing an image of the surface of the transported medium under control of a processing circuit (described later).

[0023] Similarly, the second imaging device 123b has a CIS line sensor with a life-size optical system having CMOS imaging elements linearly arranged in the main scanning direction. The second imaging device 123b also 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 123b generates and outputs an input image of the back side of the transported medium under control of a processing circuit (described later).

[0024] Note that the medium conveying device 100 may have only one of the first imaging device 123a and the second imaging device 123b disposed therein, 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. Hereinafter, the first imaging device 123a and the second imaging device 123b may be collectively referred to as the imaging device 123.

[0025] The third conveyance roller 124 and the fourth conveyance roller 125 are provided downstream of the first imaging device 123a and the second imaging device 123b in the medium conveyance direction A1. The third conveyance roller 124 is provided in the lower housing 101, and the fourth conveyance roller 125 is provided opposite the third conveyance roller 124 in the upper housing 102. The third conveyance roller 124 and the fourth conveyance roller 125 discharge the medium conveyed by the first conveyance roller 120 and the second conveyance roller 121 onto the discharge tray 104.

[0026] The brake roller 116, the second conveyor roller 121, the second image capture device 123b, and the fourth conveyor roller 125 are provided so as to be able to move upward depending on the thickness of the medium being conveyed. In this way, the brake roller 116, the second conveyor roller 121, the second image capture device 123b, and the fourth conveyor roller 125 are provided so as to be able to convey a passport as a medium. In other words, the medium conveying device 100 is able to convey a passport.

[0027] The media placed on the mounting table 103 is transported between the lower guide 107a and the upper guide 107b in the media transport direction A1 by the rotation of the feed roller 115 in the direction of arrow A11 in Figure 2, i.e., the media feed direction. When transporting the media, the brake roller 116 rotates in the direction of arrow A12, i.e., the opposite direction to the media feed direction. When multiple media are placed on the mounting table 103, the feed roller 115 and the brake roller 116 act to separate only the media placed on the mounting table 103 that are in contact with the feed roller 115. This restricts the transport of media other than the separated media (preventing double feeding).

[0028] The medium is guided by lower guide 107a and upper guide 107b and fed between first conveyor roller 120 and second conveyor roller 121. The medium is fed between first imaging device 123a and second imaging device 123b as first conveyor roller 120 and second conveyor roller 121 rotate in the directions of arrows A13 and A14, respectively. After being scanned by imaging device 123, the medium is discharged onto discharge tray 104 as third conveyor roller 124 and fourth conveyor roller 125 rotate in the directions of arrows A15 and A16, respectively.

[0029] 3A and 3B are schematic diagrams for explaining the set guide 112, the movement mechanism 113, and the flap 114. Fig. 3A is a schematic diagram of the set guide 112, the movement mechanism 113, and the flap 114 seen from the side before the medium is fed. Fig. 3B is a schematic diagram of a cross section of the medium transport path taken at the position of the first sensor 117 before the medium is fed, seen from the downstream side.

[0030] As shown in Figures 3A and 3B, the set guide 112 is a guide for setting a medium. The set guide 112 is disposed at a position facing the feed roller 115 and the brake roller 116 in the medium transport direction A1. The set guide 112 is rotatably (swingably) supported by the lower housing 101, and supports the underside of a medium placed on the mounting table 103 when the medium is not being fed. Hereinafter, the position where the set guide 112 supports the underside of a medium placed on the mounting table 103, as shown in Figures 3A and 3B, may be referred to as the set position.

[0031] The moving mechanism 113 is a cam member for moving the set guide 112. The moving mechanism 113 is disposed downstream of the set guide 112 in the medium conveying direction A1. The moving mechanism 113 is also disposed downstream of the shaft 115a in the medium conveying direction A1 so as not to come into contact with the shaft 115a, which is the rotation axis of the feed roller 115. The moving mechanism 113 is supported by the lower housing 101 so as to be rotatable (swingable) in response to a driving force from a motor (described later), and when no media is being fed, the moving mechanism 113 comes into contact with the downstream end of the set guide 112 to hold the set guide 112 in the set position. As shown in FIG. 3B , a first sensor 117 is disposed downstream of the moving mechanism 113 in the medium conveying direction A1 and in the vicinity of the moving mechanism 113. Details of the first sensor 117 will be described later.

[0032] The flap 114 is a stopper that prevents the medium from entering the nip position between the feed roller 115 and the brake roller 116 before the medium is fed. The flap 114 is disposed in a position facing the set guide 112 in the medium transport direction A1. The flap 114 is swingably provided on the upper housing 102, and when the medium is not being fed, the flap 114 engages with the set guide 112 and prevents the medium from entering the nip position between the feed roller 115 and the brake roller 116.

[0033] 4A and 4B are schematic diagrams for explaining the operations of the set guide 112, the movement mechanism 113, and the flap 114. Fig. 4A is a schematic diagram of the set guide 112, the movement mechanism 113, and the flap 114 when feeding a medium, viewed from the side. Fig. 4B is a schematic diagram of a cross section of the medium transport path taken at the position of the first sensor 117 when feeding a medium, viewed from the downstream side.

[0034] As shown in FIGS. 4A and 4B , when a medium is fed, the moving mechanism 113 swings downward in response to the driving force from the motor and moves away from the downstream end of the set guide 112. When the downstream end of the set guide 112 moves away from the moving mechanism 113 and is no longer held by the moving mechanism 113, the set guide 112 swings below the medium transport surface and moves away from the underside of the medium placed on the mounting table 103. Hereinafter, the position where the set guide 112 moves away from the underside of the medium placed on the mounting table 103, as shown in FIGS. 4A and 4B , may be referred to as the release position. When the set guide 112 is placed in the release position, the engagement between the flap 114 and the set guide 112 is released. As a result, the flap 114 is pushed by the leading edge of the medium placed on the mounting table 103 and swings, allowing the medium to enter the nip position between the feed roller 115 and the brake roller 116. In this manner, the flap 114 allows the medium to enter the nip position between the feed roller 115 and the brake roller 116 when the set guide 112 is placed in the release position.

[0035] Fig. 5 is a schematic diagram for explaining the first sensor 117, the second sensor 118, the third sensor 119, and the fourth sensor 122. Fig. 5 is a schematic diagram showing only the first sensor 117, the second sensor 118, the third sensor 119, and the fourth sensor 122 as viewed from the downstream side, with components other than the first sensor 117, the second sensor 118, the third sensor 119, and the fourth sensor 122 not shown.

[0036] As shown in FIG. 5, the first sensor 117 is a regression prism sensor, and includes a light emitting element 117a, a light receiving element 117b, a first light guiding portion 117c, a second light guiding portion 117d, a third light guiding portion 117e, and a coupling portion 117f.

[0037] The light emitting element 117a and the light receiving element 117b are mounted on a substrate 131 provided in the lower housing 101 and are used to detect a medium. The light emitting element 117a is disposed outside the medium transport path, with the lower guide 107a in between. The light emitting element 117a is an LED (Light Emitting Diode) or the like, and is disposed to face the lower end of the first light guiding unit 117c, and emits light toward the lower end of the first light guiding unit 117c. The light receiving element 117b is disposed outside the medium transport path, with the lower guide 107a in between. The light receiving element 117b is disposed to face the lower end of the second light guiding unit 117d, and receives light emitted by the light emitting element 117a and guided by the first light guiding unit 117c, the third light guiding unit 117e, and the second light guiding unit 117d, from the second light guiding unit 117d. The light receiving element 117b generates and outputs a first optical signal, which is an electrical signal corresponding to the intensity of the received light. The first optical signal is generated, for example, so that the signal value is proportional to the amount of light received by the light receiving element 117b. Note that the signal value of the first optical signal and the amount of light received by the light receiving element 117b may have other relationships, such as inverse proportionality. Because the light emitting element 117a and the light receiving element 117b are mounted on the same substrate 131, the medium conveying device 100 can reduce the number of substrates, thereby reducing the device cost and size.

[0038] 3A, 3B, 4A, and 4B, the light-emitting element 117a and the light-receiving element 117b are disposed outside the medium transport path, with the lower guide 107a sandwiched between them. Furthermore, the substrate 131 on which the light-emitting element 117a and the light-receiving element 117b are mounted is disposed in a position facing the movement mechanism 113 in the width direction A2. Furthermore, the light-emitting element 117a and the light-receiving element 117b are disposed downstream of the movement mechanism 113 in the medium transport direction A1, so as to be spaced a predetermined distance or more from the movement mechanism 113. The predetermined distance is, for example, 3 mm.

[0039] First light guiding section 117c, second light guiding section 117d, and third light guiding section 117e are light guides such as prisms, and are made of a material such as polycarbonate. First light guiding section 117c is disposed outside the medium transport path, sandwiching lower guide 107a therebetween. First light guiding section 117c is provided in lower housing 101 so that its lower end faces light emitting element 117a and its upper end faces lower guide 107a, and guides light emitted from light emitting element 117a to the medium transport path. Second light guiding section 117d is disposed outside the medium transport path, sandwiching lower guide 107a therebetween. Second light guiding section 117d is provided in lower housing 101 so that its upper end faces lower guide 107a and its lower end faces light receiving element 117b, and guides light incident from the medium transport path to light receiving element 117b. Third light guiding unit 117e is an example of a light guiding unit, and is disposed outside the medium transport path, sandwiching upper guide 107b between them. Third light guiding unit 117e is formed in a U-shape such that its two lower ends face upper guide 107b, and is provided in upper housing 102 such that each lower end faces an upper end of first light guiding unit 117c and an upper end of second light guiding unit 117d, sandwiching the medium transport path between them. Third light guiding unit 117e guides light incident from its lower end facing first light guiding unit 117c to its lower end facing second light guiding unit 117d.

[0040] The coupling portion 117f couples the first light guiding portion 117c and the second light guiding portion 117d together.

[0041] Similarly, the second sensor 118 is a regression prism sensor, and includes a light emitting element 118a, a light receiving element 118b, a first light guiding portion 118c, a second light guiding portion 118d, a third light guiding portion 118e, and a coupling portion 118f.

[0042] Light-emitting element 118a and light-receiving element 118b are mounted on substrate 131 provided in lower housing 101 and are used to detect a medium. Light-emitting element 118a is disposed outside the medium transport path, with lower guide 107a in between. Light-emitting element 118a is an LED or the like, and is disposed opposite the lower end of first light guide 118c, emitting light toward the lower end of first light guide 118c. Light-receiving element 118b is disposed outside the medium transport path, with lower guide 107a in between. Light-receiving element 118b is disposed opposite the lower end of second light guide 118d, and receives light emitted by light-emitting element 118a and guided by first light guide 118c, third light guide 118e, and second light guide 118d, from second light guide 118d. The light receiving element 118b generates and outputs a second optical signal, which is an electrical signal corresponding to the intensity of the received light. The second optical signal is generated, for example, so that the signal value is proportional to the amount of light received by the light receiving element 118b. Note that the signal value of the second optical signal and the amount of light received by the light receiving element 118b may have other relationships, such as inverse proportionality. Because the light emitting element 118a and the light receiving element 118b are mounted on the same substrate 131, the medium conveying device 100 can reduce the number of substrates, thereby reducing the device cost and size.

[0043] First light guiding section 118c, second light guiding section 118d, and third light guiding section 118e are light guides such as prisms, and are made of a material such as polycarbonate. First light guiding section 118c is disposed outside the medium transport path, sandwiching lower guide 107a therebetween. First light guiding section 118c is provided in lower housing 101 so that its lower end faces light emitting element 118a and its upper end faces lower guide 107a, and guides light emitted from light emitting element 118a to the medium transport path. Second light guiding section 118d is disposed outside the medium transport path, sandwiching lower guide 107a therebetween. Second light guiding section 118d is provided in lower housing 101 so that its upper end faces lower guide 107a and its lower end faces light receiving element 118b, and guides light incident from the medium transport path to light receiving element 118b. Third light guiding unit 118e is disposed outside the medium transport path, with upper guide 107b in between. Third light guiding unit 118e is formed in a U-shape such that its two lower ends face upper guide 107b, and is provided in upper housing 102 such that each lower end faces an upper end of first light guiding unit 118c and an upper end of second light guiding unit 118d, with the medium transport path in between. Third light guiding unit 118e guides light incident from its lower end facing first light guiding unit 118c to its lower end facing second light guiding unit 118d.

[0044] The coupling portion 118f couples the first light guiding portion 118c and the second light guiding portion 118d.

[0045] Similarly, the third sensor 119 is a regression prism sensor, and includes a light emitting element 119a, a light receiving element 119b, a first light guiding portion 119c, a second light guiding portion 119d, a third light guiding portion 119e, and a coupling portion 119f.

[0046] Light-emitting element 119a and light-receiving element 119b are mounted on substrate 131 provided in lower housing 101 and are used to detect a medium. Light-emitting element 119a is disposed outside the medium transport path, with lower guide 107a in between. Light-emitting element 119a is an LED or the like, and is disposed opposite the lower end of first light guide 119c, emitting light toward the lower end of first light guide 119c. Light-receiving element 119b is disposed outside the medium transport path, with lower guide 107a in between. Light-receiving element 119b is disposed opposite the lower end of second light guide 119d, and receives light emitted by light-emitting element 119a and guided by first light guide 119c, third light guide 119e, and second light guide 119d, from second light guide 119d. The light receiving element 119b generates and outputs a third optical signal, which is an electrical signal corresponding to the intensity of the received light. The third optical signal is generated, for example, so that the signal value is proportional to the amount of light received by the light receiving element 119b. Note that the signal value of the third optical signal and the amount of light received by the light receiving element 119b may have other relationships, such as inverse proportionality. Because the light emitting element 119a and the light receiving element 119b are mounted on the same substrate 131, the medium conveying device 100 can reduce the number of substrates, thereby reducing the device cost and size.

[0047] The first light guiding section 119c, the second light guiding section 119d, and the third light guiding section 119e are light guides such as prisms, and are made of a material such as polycarbonate. The first light guiding section 119c is disposed outside the medium transport path, sandwiching the lower guide 107a therebetween. The first light guiding section 119c is provided in the lower housing 101 so that its lower end faces the light emitting element 119a and its upper end faces the lower guide 107a, and guides light emitted from the light emitting element 119a to the medium transport path. The second light guiding section 119d is disposed outside the medium transport path, sandwiching the lower guide 107a therebetween. The second light guiding section 119d is provided in the lower housing 101 so that its upper end faces the lower guide 107a and its lower end faces the light receiving element 119b, and guides light incident from the medium transport path to the light receiving element 119b. Third light guiding unit 119e is disposed outside the medium transport path, with upper guide 107b in between. Third light guiding unit 119e is formed in a U-shape such that its two lower ends face upper guide 107b, and is provided in upper housing 102 such that its lower ends face the upper ends of first light guiding unit 119c and second light guiding unit 119d, with the medium transport path in between. Third light guiding unit 119e guides light incident from its lower end facing first light guiding unit 119c to its lower end facing second light guiding unit 119d.

[0048] The coupling portion 119f couples the first light guiding portion 119c and the second light guiding portion 119d together.

[0049] Similarly, the fourth sensor 122 is a regression prism sensor, and includes a light emitting element 122a, a light receiving element 122b, a first light guiding portion 122c, a second light guiding portion 122d, a third light guiding portion 122e, and a coupling portion 122f.

[0050] The light emitting element 122a and the light receiving element 122b are mounted on a substrate 131 provided in the lower housing 101 and are used to detect a medium. The light emitting element 122a is disposed outside the medium transport path, with the lower guide 107a in between. The light emitting element 122a is an LED or the like, and is disposed opposite the lower end of the first light guiding section 122c, and emits light toward the lower end of the first light guiding section 122c. The light receiving element 122b is disposed outside the medium transport path, with the lower guide 107a in between. The light receiving element 122b is disposed opposite the lower end of the second light guiding section 122d, and receives light emitted by the light emitting element 122a and guided by the first light guiding section 122c, the third light guiding section 122e, and the second light guiding section 122d, from the second light guiding section 122d. The light receiving element 122b generates and outputs a fourth optical signal, which is an electrical signal corresponding to the intensity of the received light. The fourth optical signal is generated, for example, so that the signal value is proportional to the amount of light received by the light receiving element 122b. Note that the signal value of the fourth optical signal and the amount of light received by the light receiving element 122b may have other relationships, such as inverse proportionality. Because the light emitting element 122a and the light receiving element 122b are mounted on the same substrate 131, the medium conveying device 100 can reduce the number of substrates, thereby reducing the device cost and size.

[0051] The first light guiding section 122c, the second light guiding section 122d, and the third light guiding section 122e are light guides such as prisms, and are made of a material such as polycarbonate. The first light guiding section 122c is disposed outside the medium transport path, sandwiching the lower guide 107a therebetween. The first light guiding section 122c is provided in the lower housing 101 so that its lower end faces the light emitting element 122a and its upper end faces the lower guide 107a, and guides light emitted from the light emitting element 122a to the medium transport path. The second light guiding section 122d is disposed outside the medium transport path, sandwiching the lower guide 107a therebetween. The second light guiding section 122d is provided in the lower housing 101 so that its upper end faces the lower guide 107a and its lower end faces the light receiving element 122b, and guides light incident from the medium transport path to the light receiving element 122b. Third light guiding unit 122e is disposed outside the medium transport path, with upper guide 107b in between. Third light guiding unit 122e is formed in a U-shape such that its two lower ends face upper guide 107b, and is provided in upper housing 102 such that its lower ends face the upper ends of first light guiding unit 122c and second light guiding unit 122d, with the medium transport path in between. Third light guiding unit 122e guides light incident from its lower end facing first light guiding unit 122c to its lower end facing second light guiding unit 122d.

[0052] The coupling portion 122f couples the first light guiding portion 122c and the second light guiding portion 122d together.

[0053] As described above, in medium conveying device 100, the light emitting elements and light receiving elements of first sensor 117, second sensor 118, third sensor 119, and fourth sensor 122 are all mounted on the same substrate 131. Therefore, medium conveying device 100 can reduce the number of substrates, and can reduce the device cost and size.

[0054] Fig. 6 is a schematic diagram for explaining the positional relationship between the first sensor 117, the second sensor 118, the third sensor 119, and the fourth sensor 122. Fig. 6 is a schematic diagram of the lower guide 107a as viewed from above.

[0055] As shown in FIG. 6, the lower guide 107a has a first hole portion 132a, a second hole portion 132b, a third hole portion 132c, a fourth hole portion 132d, a fifth hole portion 132e, a sixth hole portion 132f, a seventh hole portion 132g, and an eighth hole portion 132h.

[0056] The first to sixth holes 132a-f are provided at approximately the same position in the medium transport direction A1, between the feed roller 115 and the brake roller 116 and the first transport roller 120 and the second transport roller 121. The first to sixth holes 132a-f are provided near the feed roller 115 and the brake roller 116 in the medium transport direction A1, particularly within a predetermined distance (for example, within 50 mm) from the center position of the nip between the feed roller 115 and the brake roller 116. The first to sixth holes 132a-f are arranged side by side with intervals between them in the width direction A2. The seventh to eighth holes 132g-h are provided at approximately the same position in the medium transport direction A1, between the first transport roller 120 and the second transport roller 121 and the imaging device 123. The seventh to eighth holes 132g-h are arranged side by side with intervals between them in the width direction A2.

[0057] The first hole 132a is an example of a first opening, and is disposed at a position facing the first light guiding portion 117c of the first sensor 117 and is provided to be engageable with the first light guiding portion 117c. The second hole 132b is an example of a second opening, and is disposed at a position facing the second light guiding portion 117d of the first sensor 117 and is provided to be engageable with the second light guiding portion 117d. The second hole 132b is also an example of an opening. The first hole 132a and the second hole 132b are provided in the lower guide 107a to allow light emitted from the light emitting element 117a of the first sensor 117 to pass through. As described above, the first light guiding portion 117c and the second light guiding portion 117d are coupled by the coupling portion 117f and are engaged with the first hole 132a and the second hole 132b. The first light guiding portion 117c and the second light guiding portion 117d are positioned in a direction along the lower guide 107a (conveying surface) by the connecting portion 117f, the first hole portion 132a and the second hole portion 132b, and are appropriately fixed to the lower housing 101.

[0058] In the width direction A2 perpendicular to the medium transport direction, the second hole 132b, which engages with the second light guiding portion 117d that guides light to the light receiving element 117b, is positioned closer to the center than the first hole 132a, which engages with the first light guiding portion 117c that guides light emitted from the light emitting element 117a. In other words, in the width direction A2 perpendicular to the medium transport direction, the light receiving element 117b is positioned closer to the center than the light emitting element 117a.

[0059] Similarly, the third hole 132c is disposed at a position facing the first light guiding portion 118c of the second sensor 118 and is provided so as to be engageable with the first light guiding portion 118c. The fourth hole 132d is disposed at a position facing the second light guiding portion 118d of the second sensor 118 and is provided so as to be engageable with the second light guiding portion 118d. The fourth hole 132d is an example of a predetermined opening, and is arranged adjacent to the second hole 132b at an interval in the width direction A2 perpendicular to the medium conveyance direction. Furthermore, the third hole 132c or the fourth hole 132d is an example of a fifth opening, and is arranged adjacent to the first hole 132a and the second hole 132b at an interval in the width direction A2 perpendicular to the medium conveyance direction. Third hole 132c and fourth hole 132d are provided in lower guide 107a to allow light emitted from light-emitting element 118a of second sensor 118 to pass therethrough. As described above, first light guiding portion 118c and second light guiding portion 118d are coupled by coupling portion 118f and engaged with third hole 132c and fourth hole 132d. First light guiding portion 118c and second light guiding portion 118d are positioned in the direction along lower guide 107a (transport surface) by coupling portion 118f, third hole 132c, and fourth hole 132d, and are appropriately fixed to lower housing 101.

[0060] In the width direction A2 perpendicular to the medium transport direction, the fourth hole 132d, which engages with the second light guide 118d that guides light to the light receiving element 118b, is positioned closer to the center than the third hole 132c, which engages with the third light guide 118e that guides light emitted from the light emitting element 118a. In other words, in the width direction A2 perpendicular to the medium transport direction, the light receiving element 118b is positioned closer to the center than the light emitting element 118a. The light emitting element 118a and the light receiving element 118b of the second sensor 118 are an example of a second light emitting element and a second light receiving element, and the medium is detected using the third hole 132c and the fourth hole 132d.

[0061] Similarly, fifth hole 132e is disposed at a position facing first light guiding portion 119c of third sensor 119 and is provided to be engageable with first light guiding portion 119c. Sixth hole 132f is disposed at a position facing second light guiding portion 119d of third sensor 119 and is provided to be engageable with second light guiding portion 119d. Fifth hole 132e and sixth hole 132f are provided in lower guide 107a to allow light emitted from light emitting element 119a of third sensor 119 to pass therethrough. As described above, first light guiding portion 119c and second light guiding portion 119d are coupled by coupling portion 119f and are engaged with fifth hole 132e and sixth hole 132f. The first light guiding portion 119c and the second light guiding portion 119d are positioned in a direction along the lower guide 107a (conveying surface) by the connecting portion 119f, the fifth hole portion 132e and the sixth hole portion 132f, and are appropriately fixed to the lower housing 101.

[0062] Similarly, seventh hole 132g is disposed at a position facing first light guiding portion 122c of fourth sensor 122 and is provided to be engageable with first light guiding portion 122c. Eighth hole 132h is disposed at a position facing second light guiding portion 122d of fourth sensor 122 and is provided to be engageable with second light guiding portion 122d. Seventh hole 132g and eighth hole 132h are provided in lower guide 107a to allow light emitted from light emitting element 122a of fourth sensor 122 to pass therethrough. As described above, first light guiding portion 122c and second light guiding portion 122d are coupled by coupling portion 122f, which is engaged with seventh hole 132g and eighth hole 132h. The first light guiding portion 122c and the second light guiding portion 122d are positioned in a direction along the lower guide 107a (transport surface) by the connecting portion 122f, the seventh hole portion 132g and the eighth hole portion 132h, and are appropriately fixed to the lower housing 101.

[0063] A peripheral portion 133 of the lower guide 107a around the first to sixth hole portions 132a to 132f is formed of a resin material having a color other than white (for example, gray or black). In particular, the peripheral portion 133 is formed of a material having a reflectance of 55% or less so that the reflectance of the peripheries of the first to sixth hole portions 132a to 132f of the lower guide 107a is 55% or less.

[0064] Similarly, the peripheral portion 134 of the lower guide 107a around the seventh and eighth hole portions 132g-h is formed of a resin material having a color other than white (for example, gray or black). In particular, the peripheral portion 134 is formed of a material having a reflectance of 55% or less so that the reflectance of the periphery of the seventh and eighth hole portions 132g-h of the lower guide 107a is 55% or less.

[0065] In the lower guide 107a, the peripheral portion 133 and the peripheral portion 134 are formed of a separate member from the other portions. Note that in the lower guide 107a, the peripheral portion 133 and / or the peripheral portion 134 may be formed of a member that is integral with the other portions. In the lower guide 107a, the reflectance of the periphery of at least one of the second hole portion 132b, the fourth hole portion 132d, the sixth hole portion 132f, and the eighth hole portion 132h may be 55% or less, and the reflectance of the periphery of the other holes may be greater than 55%.

[0066] Fig. 7 is a schematic diagram for explaining the positional relationship between first sensor 117, second sensor 118, third sensor 119, and fourth sensor 122. Fig. 7 is a schematic diagram of upper guide 107b as viewed from below.

[0067] As shown in FIG. 7, the upper guide 107b has a ninth hole portion 135a, a tenth hole portion 135b, an eleventh hole portion 135c, a twelfth hole portion 135d, a thirteenth hole portion 135e, a fourteenth hole portion 135f, a fifteenth hole portion 135g, and a sixteenth hole portion 135h.

[0068] The ninth to sixteenth hole portions 135a to 135h are arranged to face the first to eighth hole portions 132a to 132h, respectively, across the medium transport path.

[0069] The ninth hole 135a is an example of a third opening. The ninth hole 135a is disposed at a position facing a lower end of the third light guiding section 117e of the first sensor 117 on the first light guiding section 117c side, and is provided so as to be engageable with the lower end of the third light guiding section 117e on the first light guiding section 117c side. The tenth hole 135b is an example of a fourth opening. The tenth hole 135b is disposed at a position facing a lower end of the third light guiding section 117e of the first sensor 117 on the second light guiding section 117d side, and is provided so as to be engageable with the lower end of the third light guiding section 117e on the first light guiding section 117c side. That is, the third light guiding section 117e is provided so as to guide light incident from the ninth hole 135a to the tenth hole 135b. The ninth hole 135a is an example of a second guide opening. The ninth hole 135a and the tenth hole 135b are provided in the upper guide 107b to allow light emitted from the light emitting element 117a of the first sensor 117 to pass through.

[0070] Similarly, the eleventh hole 135c is disposed at a position facing the lower end of the third light guiding section 118e of the second sensor 118 on the first light guiding section 118c side and is provided so as to be engageable with the lower end of the third light guiding section 118e on the first light guiding section 118c side. The twelfth hole 135d is disposed at a position facing the lower end of the third light guiding section 118e of the second sensor 118 on the second light guiding section 118d side and is provided so as to be engageable with the lower end of the third light guiding section 118e on the first light guiding section 118c side. That is, the third light guiding section 118e is provided to guide light incident from the eleventh hole 135c to the twelfth hole 135d. The eleventh hole 135c and the twelfth hole 135d are provided in the upper guide 107b to allow light emitted from the light emitting element 118a of the second sensor 118 to pass therethrough.

[0071] Similarly, the thirteenth hole 135e is disposed at a position facing the lower end of the third light guiding section 119e of the third sensor 119 on the first light guiding section 119c side and is provided to be engageable with the lower end of the third light guiding section 119e on the first light guiding section 119c side. The fourteenth hole 135f is disposed at a position facing the lower end of the third light guiding section 119e of the third sensor 119 on the second light guiding section 119d side and is provided to be engageable with the lower end of the third light guiding section 119e on the first light guiding section 119c side. That is, the third light guiding section 119e is provided to guide light incident from the thirteenth hole 135e to the fourteenth hole 135f. The thirteenth hole 135e and the fourteenth hole 135f are provided in the upper guide 107b to allow light emitted from the light emitting element 119a of the third sensor 119 to pass through.

[0072] Similarly, the fifteenth hole 135g is disposed at a position facing the lower end of the third light guiding section 122e of the fourth sensor 122 on the first light guiding section 122c side and is provided to be engageable with the lower end of the third light guiding section 122e on the first light guiding section 122c side. The sixteenth hole 135h is disposed at a position facing the lower end of the third light guiding section 122e of the fourth sensor 122 on the second light guiding section 122d side and is provided to be engageable with the lower end of the third light guiding section 122e on the second light guiding section 122d side. That is, the third light guiding section 122e is provided to guide light incident from the fifteenth hole 135g to the sixteenth hole 135h. The fifteenth hole 135g and the sixteenth hole 135h are provided in the upper guide 107b to allow light emitted from the light emitting element 122a of the fourth sensor 122 to pass through.

[0073] A peripheral portion 136 of the upper guide 107b around the ninth to fourteenth hole portions 135a to f is formed of a resin material having a color other than white (for example, gray or black). In particular, the peripheral portion 136 is formed of a material having a reflectance of 55% or less so that the reflectance of the periphery of the ninth to fourteenth hole portions 135a to f of the upper guide 107b is 55% or less.

[0074] Similarly, a peripheral portion 137 of the upper guide 107b around the 15th and 16th hole portions 135g-h is formed of a resin material having a color other than white (for example, gray or black). In particular, the peripheral portion 136 is formed of a material having a reflectance of 55% or less so that the reflectance of the periphery of the 15th and 16th hole portions 135g-h of the upper guide 107b is 55% or less.

[0075] In the upper guide 107b, the peripheral portion 136 and the peripheral portion 137 are formed of a separate member from the other portions. Note that in the upper guide 107b, the peripheral portion 136 and / or the peripheral portion 137 may be formed of a member that is integral with the other portions. Also, in the upper guide 107b, the reflectance of the periphery of at least one of the ninth hole portion 135a, the eleventh hole portion 135c, the thirteenth hole portion 135e, and the fifteenth hole portion 135g may be 55% or less, and the reflectance of the periphery of the other holes may be greater than 55%. Also, in the upper guide 107b, the reflectance of the periphery of all the holes may be greater than 55%.

[0076] Fig. 8 is a schematic diagram for explaining the shape of first sensor 117. Fig. 8 is a perspective view of light-emitting element 117a, light-receiving element 117b, first light-guiding portion 117c, second light-guiding portion 117d, and coupling portion 117f of first sensor 117, as viewed from the downstream side.

[0077] As shown in FIG. 8, the first light guiding portion 117c is formed in a cylindrical shape. The first light guiding portion 117c includes a first cylindrical portion 117g, a second cylindrical portion 117h, and a third cylindrical portion 117i. The first cylindrical portion 117g is provided on the lower end side facing the light emitting element 117a. The second cylindrical portion 117h is provided on the upper end side facing the first hole portion 132a. The third cylindrical portion 117i is provided between the first cylindrical portion 117g and the second cylindrical portion 117h. The first cylindrical portion 117g and the second cylindrical portion 117h are provided so as to be parallel to each other, and the third cylindrical portion 117i is provided so as to be inclined with respect to the first cylindrical portion 117g and the second cylindrical portion 117h.

[0078] Similarly, the second light guiding portion 117d is formed in a cylindrical shape. The second light guiding portion 117d includes a fourth cylindrical portion 117j, a fifth cylindrical portion 117k, and a sixth cylindrical portion 117l. The fourth cylindrical portion 117j is provided on the lower end side facing the light receiving element 117b. The fifth cylindrical portion 117k is provided on the upper end side facing the second hole portion 132b. The sixth cylindrical portion 117l is provided between the fourth cylindrical portion 117j and the fifth cylindrical portion 117k. The fourth cylindrical portion 117j and the fifth cylindrical portion 117k are provided so as to be parallel to each other, and the sixth cylindrical portion 117l is provided so as to be inclined with respect to the fourth cylindrical portion 117j and the fifth cylindrical portion 117k.

[0079] In the medium conveying direction A1, the lower ends of the first light guiding section 117c and the second light guiding section 117d are arranged downstream of the upper ends of the first light guiding section 117c and the second light guiding section 117d. That is, in the medium conveying direction A1, the light emitting element 117a and the light receiving element 117b are arranged downstream of the first hole 132a and the second hole 132b. The first light guiding section 117c is bent so as to guide the light emitted from the light emitting element 117a to the first hole 132a, and the second light guiding section 117d is bent so as to guide the light incident from the second hole 132b to the light receiving element 117b.

[0080] The first sensor 117 is used to detect the leading edge of the medium fed by the feed roller 115 and the brake roller 116. The medium conveying device 100 determines whether a medium jam or skew has occurred based on the detection result of the leading edge of the medium by the first sensor 117, and stops conveyance of the medium if a medium jam or skew has occurred. The first sensor 117 needs to detect the leading edge of the medium that has passed the feed roller 115 and the brake roller 116 as soon as possible so that the medium conveying device 100 can stop conveyance of the medium as soon as possible if a medium jam or skew has occurred. Therefore, it is preferable that the positions of the first hole 132a, the second hole 132b, the ninth hole 135a, and the tenth hole 135b used to detect the leading edge of the medium are as close as possible to the nip position of the feed roller 115 and the brake roller 116.

[0081] 3B and 4B, a moving mechanism 113 is disposed upstream of the light-emitting element 117a and the light-receiving element 117b in the medium conveying direction A1 and in the vicinity of the light-emitting element 117a and the light-receiving element 117b. The moving mechanism 113 is used to move the set guide 112 that sets the medium to be supplied to the feed roller 115, and is therefore disposed in the vicinity of the feed roller 115. Also, as shown in FIGS. 3A, 3B, 4A, and 4B, the light-emitting element 117a and the light-receiving element 117b are mounted on a substrate 131, and the substrate 131 is disposed downstream of the moving mechanism 113. Wiring for applying voltage to the light-emitting element 117a and the light-receiving element 117b is mounted on the substrate 131, and therefore the light-emitting element 117a and the light-receiving element 117b need to be disposed at a position some distance away from the end of the substrate 131. As a result, the light emitting element 117a and the light receiving element 117b are disposed downstream of the feed roller 115 to some extent.

[0082] In the medium conveying device 100, the first hole 132a and the second hole 132b are located upstream of the light emitting element 117a and the light receiving element 117b, so the medium conveying device 100 can detect a jam or skew of the medium early on. This allows the medium conveying device 100 to prevent damage to the medium.

[0083] Furthermore, in the medium conveying device 100, since the first light guiding portion 117c and the second light guiding portion 117d are bent, the degree of freedom in the placement position of the light emitting element 117a and the light receiving element 117b on the substrate 131 is increased, making it easier to miniaturize the substrate 131.

[0084] In particular, the first light guiding portion 117c is bent in a dogleg shape at two locations so that the first cylindrical portion 117g, which is provided at the lower end facing the light-emitting element 117a, and the second cylindrical portion 117h, which is provided at the upper end facing the first hole 132a, are parallel to each other. Similarly, the second light guiding portion 117d is bent in a dogleg shape at two locations so that the fourth cylindrical portion 117j, which is provided at the lower end facing the light-receiving element 117b, and the fifth cylindrical portion 117k, which is provided at the upper end facing the second hole 132b, are parallel to each other. The first cylindrical portion 117g and the fourth cylindrical portion 117j are arranged so as to be substantially perpendicular to the mounting surface of the substrate 131. The second cylindrical portion 117h and the fifth cylindrical portion 117k are arranged so as to be substantially perpendicular to the lower guide 107a. Therefore, in the medium conveying device 100, the substrate 131 is disposed substantially parallel to the lower guide 107a, which stabilizes the substrate 131 and facilitates assembly.

[0085] Because the substrate 131 is disposed approximately parallel to the lower guide 107a, the light emitting element 118a and the light receiving element 118b of the second sensor 118, which is disposed rotated 180 degrees parallel to the medium conveyance surface relative to the first sensor 117 as described below, can also be mounted on the same substrate 131. Furthermore, the light emitting element and the light receiving element of the third sensor 119 and the fourth sensor 122, whose first and second light guiding portions are not bent as described below, can also be mounted on the same substrate 131. Therefore, the medium conveyance device 100 can reduce the number of substrates, thereby reducing the device cost and size.

[0086] The first light guiding portion 117c and the second light guiding portion 117d may be bent at only one position, or may be bent at any angle.

[0087] The coupling portion 117f has a first side surface 117m, a second side surface 117n, and a third side surface 117o. The first side surface 117m has a plane perpendicular to the medium transport direction A1 and is attached to the substrate 131 so that the first light guiding portion 117c and the second light guiding portion 117d are supported on the substrate 131. The second side surface 117n has a plane parallel to the medium transport direction A1 and the vertical direction A3 and is attached to one end of the first side surface 117m so that the first light guiding portion 117c is supported by the first side surface 117m. The third side surface 117o has a plane parallel to the medium transport direction A1 and the vertical direction A3 and is attached to the other end of the first side surface 117m so that the second light guiding portion 117d is supported by the first side surface 117m.

[0088] The second side surface 117n and the third side surface 117o have planes parallel to the medium conveyance direction A1 and the up-down direction A3, and thus block disturbance light that leaks toward the second light guide portion 117d out of the light emitted from the light-emitting element 117a and guided by the first light guide portion 117c. This allows the medium conveyance device 100 to prevent the light-receiving element 117b from receiving disturbance light that leaks from the first light guide portion 117c.

[0089] Fig. 9A is a schematic diagram for explaining the shape of first light guiding section 117c. Fig. 9A is a schematic diagram of light emitting element 117a and first light guiding section 117c of first sensor 117 as viewed from the side.

[0090] 9A, a lower end 117p of first light guiding section 117c facing light emitting element 117a has a lens shape for guiding the light emitted from light emitting element 117a as parallel light. That is, a collimating lens (convex lens) is formed at lower end 117p of first light guiding section 117c. The diffused light emitted from light emitting element 117a is converted into parallel light by the lens formed at lower end 117p and travels in a direction parallel to the extension direction of first cylindrical section 117g.

[0091] As a result, first light guide 117c can suppress diffusion of incident light and efficiently emit light to third light guide 117e, thereby suppressing a decrease in the amount of light received by light receiving element 117b. As described above, in medium conveying device 100, lower guide 107a and upper guide 107b are arranged to be separated by a predetermined distance or more so that passports can be conveyed. Therefore, the distance over which light emitted from light emitting element 117a reaches light receiving element 117b is large, and the amount of light received by light receiving element 117b is significantly attenuated relative to the amount of light emitted by light emitting element 117a. However, in medium conveying device 100, the diffused light emitted from light emitting element 117a is converted into parallel light, thereby suppressing a decrease in light intensity and allowing light receiving element 117b to receive a sufficient amount of light.

[0092] As described above, the third cylindrical portion 117i is disposed so as to be inclined with respect to the first cylindrical portion 117g and the second cylindrical portion 117h. The third cylindrical portion 117i is determined so that the angle θ1 formed between the extension direction of the first cylindrical portion 117g and the second cylindrical portion 117h and the extension direction of the third cylindrical portion 117i is equal to or less than the critical angle of the first light guiding portion 117c (third cylindrical portion 117i). That is, the first light guiding portion 117c is bent so as to totally reflect at least light incident parallel to the extension direction of the first cylindrical portion 117g. Furthermore, the first light guiding portion 117c is bent so as to totally reflect light incident parallel to the extension direction of the first cylindrical portion 117g and reflected by the third cylindrical portion 117i toward the second cylindrical portion 117h. For example, if first light guiding section 117c is made of polycarbonate, the refractive index is 1.585 and the critical angle is 39.1°. While the critical angle of polycarbonate is 39.1°, angle θ1 in this embodiment is 36°. Therefore, first light guiding section 117c can efficiently guide and emit incident light.

[0093] Fig. 9B is a schematic diagram for explaining the shape of second light guide section 117d. Fig. 9B is a schematic diagram of light receiving element 117b of first sensor 117 and second light guide section 117d as viewed from the side.

[0094] As described above, the sixth cylindrical portion 117l is disposed so as to be inclined relative to the fourth cylindrical portion 117j and the fifth cylindrical portion 117k. The sixth cylindrical portion 117l is determined so that the angle θ2 formed between the extension direction of the fourth cylindrical portion 117j and the fifth cylindrical portion 117k and the extension direction of the sixth cylindrical portion 117l is equal to or less than the critical angle of the second light guiding portion 117d (sixth cylindrical portion 117l). That is, the second light guiding portion 117d is bent so as to totally reflect at least light incident parallel to the extension direction of the fifth cylindrical portion 117k. Furthermore, the second light guiding portion 117d is bent so as to totally reflect light incident parallel to the extension direction of the fifth cylindrical portion 117k and reflected by the sixth cylindrical portion 117l toward the fourth cylindrical portion 117j. This allows the second light guiding portion 117d to efficiently guide and emit the incident light.

[0095] The second sensor 118 has a similar structure to the first sensor 117, and the components of the second sensor 118 are the same as those of the first sensor 117. However, as described in FIG. 5, in the width direction A2, the light receiving element 117b of the first sensor 117 is disposed closer to the center than the light emitting element 117a, and the light receiving element 118b of the second sensor 118 is disposed closer to the center than the light emitting element 118a. Therefore, in the second sensor 118, the light emitting element 118a and the light receiving element 118b are disposed upstream of the third hole 132c and the fourth hole 132d. The first light guiding section 118c having a lens shape is disposed so as to face the light emitting element 118a. Therefore, first to third light guiding sections 118c-e and connecting section 118f of second sensor 118 are arranged rotated 180 degrees parallel to the medium conveyance surface relative to first to third light guiding sections 117c-e and connecting section 117f of first sensor 117. This allows medium conveyance device 100 to use common components for first sensor 117 and second sensor 118, thereby reducing device costs. Note that the components of second sensor 118 may be different from the components of first sensor 117.

[0096] Similarly, the third sensor 119 and the fourth sensor 122 have a structure similar to that of the first sensor 117, and the components of the third sensor 119 and the fourth sensor 122 share the same components as those of the first sensor 117. However, as shown in FIG. 5 , the first light guide 119c and the second light guide 119d of the third sensor 119 and the first light guide 122c and the second light guide 122d of the fourth sensor 122 are not bent. Therefore, in the third sensor 119, the light-emitting element 119a and the light-receiving element 119b are positioned in the same positions as the fifth hole 132e and the sixth hole 132f in the medium conveyance direction A1. In the fourth sensor 122, the light-emitting element 122a and the light-receiving element 122b are positioned in the same positions as the seventh hole 132g and the eighth hole 132h in the medium conveyance direction A1. As with the second sensor 118, the first and second light guiding sections 119c-d of the third sensor 119 and the first and second light guiding sections 122c-d of the fourth sensor 122 may use components common to the first and second light guiding sections 117c-d of the first sensor 117.

[0097] 10A and 10B are schematic diagrams for explaining coupling portion 117f. Fig. 10A is a schematic diagram of a cross section of lower housing 101, with first sensor 117 engaged, taken at the position of coupling portion 117f, viewed from the downstream side. Fig. 10B is a schematic diagram of a cross section of lower housing 101, with first sensor 117 engaged, taken at a position upstream of first sensor 117, viewed from the upstream side. Since the coupling portions of first sensor 117, second sensor 118, third sensor 119, and fourth sensor 122 have the same configuration, only first sensor 117 will be described below as a representative.

[0098] 10A and 10B , coupling portion 117f is supported on substrate 131 on which light-emitting element 117a and light-receiving element 117b are mounted. As described above, first light guiding portion 117c and second light guiding portion 117d are coupled by coupling portion 117f and engaged with first hole 132a and second hole 132b. First light guiding portion 117c and second light guiding portion 117d are positioned in the up-down direction A3 by coupling portion 117f, first hole 132a, second hole 132b, and substrate 131, and are appropriately fixed to lower housing 101.

[0099] Furthermore, in lower housing 101, light blocking member 138 is disposed between the space between light emitting element 117a and first light guiding section 117c and the space between second light guiding section 117d and light receiving element 117b. Light blocking member 138 is a plate-like member that does not transmit light. Light blocking member 138 prevents diffused light emitted from light emitting element 117a from leaking toward light receiving element 117b and being received by light receiving element 117b.

[0100] 11 is a schematic diagram for explaining the path of light in the first sensor 117, and is a schematic diagram of the first sensor 117 as seen from the upstream side. Since the paths of light in the first sensor 117, second sensor 118, third sensor 119, and fourth sensor 122 are similar, only the first sensor 117 will be described below as a representative.

[0101] 11, light emitted from light-emitting element 117a enters first light guiding section 117c and is guided by first light guiding section 117c to the medium transport path. The light guided to the medium transport path by first light guiding section 117c enters third light guiding section 117e from a lower end thereof facing first light guiding section 117c and is guided by third light guiding section 117e to the medium transport path via a lower end thereof facing second light guiding section 117d. The light guided to the medium transport path by third light guiding section 117e enters second light guiding section 117d and is guided by second light guiding section 117d to light-receiving element 117b.

[0102] When a medium is present on the medium transport path at a position opposite first sensor 117, the light emitted from light emitting element 117a is blocked by the medium. Therefore, the signal value of the first optical signal changes depending on whether a medium is present or not at the position of first sensor 117. Similarly, the signal values ​​of the second optical signal, third optical signal, and fourth optical signal change depending on whether a medium is present or not at the positions of second sensor 118, third sensor 119, and fourth sensor 122, respectively.

[0103] 12A and 12B are schematic diagrams for explaining the technical significance of arranging the light receiving element 117b (118b) closer to the center than the light emitting element 117a (118a) in the width direction A2. Fig. 12A is a schematic diagram of the first sensor 117 as viewed from the upstream side. Fig. 12B is a schematic diagram of the sensor S as viewed from the upstream side, in which the light receiving element R is arranged outside the light emitting element E.

[0104] 12A shows a state in which a medium M is present at a position facing the light receiving element 117b of the first sensor 117, but is not present at a position facing the light emitting element 117a arranged outside the light receiving element 117b. FIG. 12B shows a state in which a medium M is present at a position facing the light emitting element E of the sensor S, but is not present at a position facing the light receiving element R arranged outside the light emitting element E.

[0105] As shown in Figures 12A and 12B, if the medium is transported at an angle or if the medium is small, it is possible that medium M is present only at the inner position facing the light-emitting element and the light-receiving element, and not at the outer position. As shown in Figure 12B, if light-receiving element R is positioned outside light-emitting element E, medium M may be present at the position facing light-emitting element E, but medium M may not be present at the position facing light-receiving element R. In this case, light emitted from light-emitting element E and guided by the light-guiding unit facing light-emitting element E is blocked by medium M in the medium transport path and does not reach the light-guiding unit located above. However, the light may be reflected by medium M, enter the light-guiding unit facing light-receiving element R, and reach light-receiving element R. In this case, the medium transport device may erroneously determine that medium M is not present at sensor S, even though medium M is actually present at sensor S.

[0106] 12A, in medium conveying device 100, light receiving element 117b is disposed closer to the center in width direction A2 than light emitting element 117a. In this case, light emitted from light emitting element 117a and guided by first light guiding section 117c is further guided by third light guiding section 117e and emitted from third light guiding section 117e to the medium conveying path. Even if this light is reflected by medium M, the light is reflected upward and does not reach light receiving element 117b. Therefore, medium conveying device 100 can prevent erroneous determination that medium M is not present at the position of first sensor 117 when medium M is actually present at the position of first sensor 117.

[0107] 13A and 13B are schematic diagrams for explaining the technical significance of setting the reflectance around each hole in lower guide 107a and upper guide 107b to 55% or less. Fig. 13A is a schematic diagram of the medium transport path as seen from the side. Fig. 13B is a graph showing the relationship between the reflectance around each hole in lower guide 107a and upper guide 107b and the amount of light received by light receiving element 117b.

[0108] As described above, in the medium conveying device 100, the lower guide 107a and the upper guide 107b are arranged so as to be spaced apart by a predetermined distance or more so that passports can be conveyed. Therefore, as shown in FIG. 13A , disturbance light L entering through the medium conveyance or discharge port may reflect between the lower guide 107a and the upper guide 107b and enter the fourth hole 132d, which faces the second light guide 117d that guides light to the light receiving element 117b. Furthermore, when a medium such as paper is conveyed, if a portion of the medium is bent, curled, or lifted during conveyance, disturbance light L entering through the medium conveyance or discharge port may enter the medium conveyance path through the gap. In this case, disturbance light L entering through the medium conveyance or discharge port may reflect between the medium and the lower guide 107a or the upper guide 107b and enter the fourth hole 132d.

[0109] Of the media supported by the medium conveying device 100, the light receiving element 117b receives the largest amount of light when conveyed is a transparent carrier sheet. In the medium conveying device 100, the amount of light received by the light receiving element 117b when a transparent carrier sheet is conveyed as a medium is approximately half the amount of light received when no medium is conveyed. As described above, the first optical signal is generated so that its signal value is proportional to the amount of light received by the light receiving element 117b. For example, if the light emission amount of the light emitting element 117a is adjusted so that the signal value of the first optical signal when no medium is conveyed is 2.4 [V], the signal value of the first optical signal when a transparent carrier sheet is conveyed is 1.2 [V].

[0110] In the medium transport device 100, the decision threshold value that is compared with the first optical signal to determine whether a medium is present or not is set to a value between the signal value of the first optical signal when no medium is being transported and the signal value of the first optical signal when a transparent carrier sheet is being transported. In other words, the decision threshold value is set to a value between the signal value of the first optical signal when no medium is being transported and half of that signal value.

[0111] The medium conveying device 100 adjusts the light emission intensity of the light-emitting element 117a immediately after startup, taking into account the influence of ambient light in the installation environment. The medium conveying device 100 irradiates the light-emitting element 117a with light while no medium is being conveyed immediately after startup, causing the light-receiving element 117b to generate a first optical signal. The medium conveying device 100 adjusts the light emission intensity of the light-emitting element 117a so that the signal value of the first optical signal becomes a predetermined value (e.g., 2.4 [V]). However, if disturbance light enters the medium conveying path when the light emission intensity is adjusted, the light emission intensity is adjusted so that the signal value of the first optical signal becomes the predetermined value with the disturbance light present. Thereafter, when the medium conveying device 100 determines the presence or absence of a medium without disturbance light entering, the signal value of the first optical signal generated by the light-receiving element 117b when the light-emitting element 117a is made to emit light at the adjusted light emission intensity becomes smaller than the predetermined value.

[0112] Therefore, in consideration of the possibility that ambient light may enter the medium transport path when the light emission amount is adjusted, it is preferable to set the judgment threshold to a value smaller than the average value of the signal value (predetermined value) of the first optical signal when the light emission amount is adjusted and half of that signal value. For example, the judgment threshold is set to a value (e.g., 1.6 [V]) that is 2 / 3 of the signal value (predetermined value) of the first optical signal when the light emission amount of the light emitting element 117a is adjusted.

[0113] Graph 1300 shown in Figure 13B shows the results of measuring the signal value of the first optical signal when disturbance light enters through the media transport opening of the media transport device while changing the guides so that the colors around the holes in the lower and upper guides are different. The horizontal axis of Figure 13B represents the reflectance of each guide, and the vertical axis represents the signal value of the first optical signal when disturbance light enters. As shown in graph 1300, the higher the reflectance of each guide, the larger the signal value of the first optical signal when disturbance light enters, and the lower the reflectance of each guide, the smaller the signal value of the first optical signal when disturbance light enters.

[0114] As described above, if the signal value (predetermined value) of the first optical signal during adjustment of the light emission intensity is 2.4 [V] and the judgment threshold is 1.6 [V], which is two-thirds of that value, the difference is 0.8 [V]. If the received light intensity due to disturbance light during adjustment of the light emission intensity exceeds 0.8 [V], the signal value of the first optical signal generated by the light receiving element 117b when the light emitting element 117a emits light at the adjusted light emission intensity in a state where no disturbance light is present will be lower than the judgment threshold. In this case, the medium conveying device 100 cannot accurately determine whether a medium is present or absent. Therefore, the signal value of the first optical signal during disturbance light entry must be kept below 0.8 [V]. It is preferable to set the reflectivity of each guide to 55% or less so that the signal value of the first optical signal during disturbance light entry is 0.8 [V] or less.

[0115] That is, it is preferable that the reflectance of each guide is set so that the signal value of the first optical signal when disturbance light enters is equal to or less than the difference between the signal value of the first optical signal when no medium is being transported in an environment without disturbance light and the judgment threshold. As described above, if the signal value of the first optical signal when no medium is being transported in an environment without disturbance light is 2.4 [V] and the judgment threshold is 1.6 [V], which is two-thirds of that value, the reflectance of each guide is set to 55% or less.

[0116] As described above, the amount of light received by light receiving element 117b when a transparent carrier sheet is conveyed as the medium is approximately half the amount of light received when no medium is conveyed, and the signal value of the first optical signal is 1.2 [V]. If the judgment threshold is set to the average value of the signal value of the first optical signal when no medium is conveyed in an environment without disturbance light and the signal value of the first optical signal when a transparent carrier sheet is conveyed as the medium, the judgment threshold is set to 1.8 [V]. In this case, it is preferable to set the reflectance of each guide to 50% or less so that the signal value of the first optical signal when disturbance light is introduced is 0.6 [V] or less.

[0117] Furthermore, as described above, in medium conveying device 100, lower guide 107a and upper guide 107b are arranged to be spaced apart by a predetermined distance or more so that passports can be conveyed. Therefore, in medium conveying device 100, light emitted from light-emitting element 117a but not passing through third light-guiding section 117e is likely to be reflected by upper guide 107b and / or lower guide 107a and mistakenly enter light-receiving element 117b as disturbance light. By reducing the reflectivity of each guide, medium conveying device 100 can also prevent disturbance light from mistakenly entering light-receiving element 117b.

[0118] FIG. 14 is a block diagram showing a schematic configuration of the medium conveying device 100. As shown in FIG.

[0119] In addition to the above-described components, the medium conveying device 100 further includes a motor 151, an interface device 152, a storage device 160, a processing circuit 170, and the like.

[0120] The motor 151 has one or more motors, and rotates the moving mechanism 113 to move the set guide 112 in response to a control signal from the processing circuit 170. The motor 151 also rotates the feed roller 115, the brake roller 116, and the first to fourth transport rollers 120, 121, 124, and 125 in response to a control signal from the processing circuit 170 to feed and transport the medium.

[0121] The interface device 152 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 mobile information terminal, etc.) to transmit and receive input images and various information. Instead of the interface device 152, a communication unit having an antenna for transmitting and receiving wireless signals and a wireless communication interface device 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).

[0122] The storage device 160 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 160 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 160 from a computer-readable 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.

[0123] The processing circuit 170 operates based on a program stored in advance in the storage device 160. The processing circuit is, for example, a CPU (Central Processing Unit). The processing circuit 170 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.

[0124] The processing circuit 170 is connected to the operation device 105, the display device 106, the medium sensor 111, the first sensor 117, the second sensor 118, the third sensor 119, the fourth sensor 122, the imaging device 123, the motor 151, the interface device 152, the storage device 160, etc., and controls each of these components. The processing circuit 170 controls the driving of the motor 151, controls the imaging of the imaging device 123, etc., controls the transportation of the medium, generates an input image, and transmits it to the information processing device via the interface device 152.

[0125] FIG. 15 is a diagram showing a schematic configuration of the storage device 160 and the processing circuit 170. As shown in FIG.

[0126] 15, the storage device 160 stores a control program 161, a determination program 162, and the like. Each of these programs is a functional module implemented by software running on a processor. The processing circuitry 170 reads each program stored in the storage device 160 and operates in accordance with the read program. As a result, the processing circuitry 170 functions as a control unit 171 and a determination unit 172.

[0127] FIG. 16 is a flowchart showing an example of the operation of the medium reading process of the medium conveying device 100.

[0128] An example of the operation of the medium reading process of the medium conveying device 100 will be described below with reference to the flowchart shown in Fig. 16. The flow of the operation described below is executed mainly by the processing circuit 170 in cooperation with each element of the medium conveying device 100 based on a program stored in advance in the storage device 160. The flow of the operation shown in Fig. 16 is executed periodically.

[0129] First, the control unit 171 waits until a user inputs an instruction to read a medium using the operation device 105 and an operation signal instructing to read a medium is received from the operation device 105 (step S101).

[0130] Next, control unit 171 acquires a medium signal from medium sensor 111, and determines whether or not a medium is placed on placement table 103 based on the acquired medium signal (step S102).

[0131] If no medium is placed on the placement table 103, the control unit 171 returns the process to step S101 and waits until a new operation signal is received from the operation device 105.

[0132] On the other hand, if a medium is placed on the placement table 103, the control unit 171 drives the motor 151 (step S103). The control unit 171 drives the motor 151 to rotate the movement mechanism 113 and move the set guide 112 to the release position, making it possible to feed the medium. The control unit 171 also drives the motor 151 to rotate the feed roller 115, the brake roller 116, and the first to fourth transport rollers 120, 121, 124, and 125, thereby feeding and transporting the medium.

[0133] Next, the determination unit 172 receives the first optical signal, the second optical signal, the third optical signal, and the fourth optical signal from the first sensor 117, the second sensor 118, the third sensor 119, and the fourth sensor 122, respectively (step S104).

[0134] Next, the determination unit 172 determines whether a media jam has occurred based on the first optical signal, the second optical signal, and the third optical signal received from the first sensor 117, the second sensor 118, and the third sensor 119 (step S105).

[0135] The determination unit 172 determines whether the leading edge of the medium has reached the position of any of the first sensor 117, second sensor 118, and third sensor 119. The determination unit 172 determines that the leading edge of the medium has reached the position of the sensor that outputted the respective optical signal when the signal value of each optical signal changes from a value indicating that the medium is not present to a value indicating that the medium is present. In other words, the determination unit 172 determines that the leading edge of the medium has reached the position of the sensor that outputted the respective optical signal when the signal value of each optical signal received immediately before is equal to or greater than the determination threshold and the signal value of the optical signal received this time is less than the determination threshold.

[0136] The determination unit 172 determines that a medium jam has occurred if the leading edge of the medium has not reached the position of any of the first sensor 117, second sensor 118, and third sensor 119 when a first predetermined time has elapsed since the start of medium feeding. On the other hand, the determination unit 172 determines that a medium jam has not occurred if the leading edge of the medium has reached the position of any of the sensors before the first predetermined time has elapsed since the start of medium feeding. Furthermore, the determination unit 172 determines that a medium jam has not occurred if the first predetermined time has not yet elapsed since the start of medium feeding.

[0137] In this way, the determination unit 172 determines whether or not a medium jam has occurred based on the signals output from the light receiving elements 117b, 118b, and 119b. Note that the determination unit 172 may determine whether or not a medium jam has occurred based on only at least one of the first optical signal, the second optical signal, and the third optical signal.

[0138] If a medium jam occurs, the control unit 171 stops the motor 151 to stop feeding and transporting the medium (step S106), and ends the series of steps. By stopping feeding and transporting the medium when a medium jam occurs, the control unit 171 can prevent damage to the medium. Furthermore, the control unit 171 displays a message that an abnormality has occurred on the display device 106, or transmits the message to the information processing device via the interface device 152, and notifies the user of a warning.

[0139] On the other hand, if a media jam has not occurred, the control unit 171 determines whether or not a media skew has occurred based on the first optical signal, the second optical signal, and the third optical signal received from the first sensor 117, the second sensor 118, and the third sensor 119 (step S107).

[0140] The determination unit 172 determines whether the leading edge of the medium has reached the positions of the first sensor 117, the second sensor 118, and the third sensor 119, in the same manner as in step S105. The determination unit 172 determines that medium skew has occurred if a second predetermined time has elapsed since the leading edge of the medium reached the position of one of the sensors and the leading edge of the medium has not yet reached the position of the other sensors. On the other hand, the determination unit 172 determines that medium skew has not occurred if the leading edge of the medium reaches the position of one of the sensors before the second predetermined time has elapsed since the leading edge of the medium reached the position of the other sensor. Furthermore, the determination unit 172 determines that medium skew has not occurred if the second predetermined time has not yet elapsed since the leading edge of the medium reached the position of one of the sensors.

[0141] In this way, the determination unit 172 determines whether or not medium skew has occurred based on the signals output from the light receiving elements 117b, 118b, and 119b. The determination unit 172 may also determine whether or not medium skew has occurred based on only two of the first optical signal, the second optical signal, and the third optical signal. The determination unit 172 may also acquire an input image from the imaging device 123 and determine whether or not a medium jam has occurred based on the acquired input image. In this case, the determination unit 172 uses a known image processing technique to determine whether or not a medium is included in the input image. The determination unit 172 determines that medium skew has occurred if the input image acquired from the imaging device 123 includes a medium before the leading edge of the medium reaches the positions of the first sensor 117, the second sensor 118, and the third sensor 119. In this case, the determining unit 172 may determine whether or not skew of the medium has occurred based on any one of the first optical signal, the second optical signal, and the third optical signal and the input image.

[0142] If skew of the medium occurs, the control unit 171 stops the motor 151 to stop feeding and transporting the medium (step S106), and ends the series of steps. By stopping feeding and transporting the medium when skew of the medium occurs, the control unit 171 can prevent damage to the medium. Furthermore, the control unit 171 displays a message that an abnormality has occurred on the display device 106, or transmits the message to the information processing device via the interface device 152, and notifies the user of a warning.

[0143] On the other hand, if no skew of the medium has occurred, the control unit 171 determines whether the leading edge of the medium has reached the position of the imaging device 123 based on the fourth optical signal received from the fourth sensor 122 (step S108).

[0144] When the signal value of the fourth optical signal changes from a value indicating the absence of a medium to a value indicating the presence of a medium, the determination unit 172 determines that the leading edge of the medium has reached the position of the fourth sensor 122. That is, when the signal value of the fourth optical signal received immediately before is equal to the determination threshold and the signal value of the fourth optical signal received this time is less than the determination threshold, the determination unit 172 determines that the leading edge of the medium has reached the position of the fourth sensor 122. When a third predetermined time has elapsed since the determination unit 172 determined that the leading edge of the medium has reached the position of the fourth sensor 122, the determination unit 172 determines that the leading edge of the medium has reached the position of the imaging device 123.

[0145] If the leading edge of the medium has not reached the position of the imaging device 123, the determination unit 172 returns the process to step S104, and repeats the processes of steps S104 to S108 (step S108).

[0146] On the other hand, when the leading edge of the medium reaches the position of the imaging device 123, the control unit 171 causes the imaging device 123 to start capturing an image of the medium and acquires an input image from the imaging device 123. The control unit 171 transmits the acquired input image to the information processing device via the interface device 152 (step S109).

[0147] Next, control unit 171 determines whether or not a medium remains on mounting table 103 based on the medium signal obtained from medium sensor 111 (step S110). If a medium remains on mounting table 103, control unit 171 returns the process to step S104 and repeats the processes of steps S104 to S110.

[0148] On the other hand, if there are no media remaining on the mounting table 103, the control unit 171 stops the motor 151 (step S111) and ends the series of steps.

[0149] Note that either the process of step S105 or step S107 may be omitted.

[0150] As described above in detail, in medium conveying device 100, the reflectance around the holes provided on the medium conveying path for guiding light emitted from each of the light-emitting elements of first to fourth sensors 117-119, 122 to each of the light-receiving elements is equal to or less than a predetermined value. This makes it possible for medium conveying device 100 to prevent erroneous determination that a medium is not present when a medium is actually present due to disturbance light. Therefore, medium conveying device 100 can more accurately detect the medium using the light-emitting elements and light-receiving elements.

[0151] Furthermore, in the medium conveying device 100, a first hole 132a and a second hole 132b for detecting a medium are provided between the feed roller 115 and the first conveying roller 120 and the second conveying roller 121. Meanwhile, the light emitting element 117a and the light receiving element 117b are provided downstream of the first hole 132a and the second hole 132b so as to avoid the movement mechanism 113 of the set guide 112. Furthermore, the first light guiding portion 117c and the second light guiding portion 117d, which are prisms that guide light emitted from the light emitting element 117a to the light receiving element 117b, are bent between the first hole 132a and the second hole 132b and the light emitting element 117a and the light receiving element 117b. This makes it possible for the medium conveying device 100 to detect a medium that has passed through the feed roller 115 as early as possible while effectively utilizing the space within the housing. Therefore, the medium conveying device 100 can appropriately arrange the light emitting element 117a and the light receiving element 117b.

[0152] Although a preferred embodiment of medium conveying device 100 has been described above, medium conveying device 100 is not limited to the above embodiment. For example, in the medium conveying direction A1, the first and second light guiding portions of first sensor 117 and second sensor 118 may not be bent, and the light emitting element and light receiving element may be disposed in the same position as the corresponding hole. Alternatively, lower guide 107a and upper guide 107b may be provided so that the reflectance around each hole is less than 55%.

[0153] Alternatively, in first sensor 117, second sensor 118, third sensor 119, and / or fourth sensor 122, the light-emitting element, light-receiving element, first light-guiding section, and second light-guiding section may be disposed in upper housing 102, and the third light-guiding section may be disposed in lower housing 101. In this case, upper guide 107b is an example of a first guide, and lower guide 107a is an example of a second guide. In this case, lower guide 107a and upper guide 107b are also provided with holes that engage with the ends of the light-guiding sections, and lower guide 107a and upper guide 107b are configured so that the reflectance around each hole is 55% or less. In this case, set guide 112, movement mechanism 113, and feed roller 115 may be disposed in upper housing 102, and flap 114 and brake roller 116 may be disposed in lower housing 101.

[0154] Furthermore, a reflective member such as a mirror may be used instead of the third light guiding section in first sensor 117, second sensor 118, third sensor 119, and / or fourth sensor 122. Alternatively, the third light guiding section may be omitted, and medium conveying device 100 may determine whether a medium is present by determining whether light emitted from the light emitting element has been reflected by the medium or the opposing guide based on the signal value of the optical signal output from each light receiving element. Furthermore, the first light guiding section and / or second light guiding section may be omitted in first sensor 117, second sensor 118, third sensor 119, and / or fourth sensor 122, and the light emitting element and / or light receiving element may be disposed near the corresponding hole.

[0155] FIG. 17 is a schematic diagram for explaining the arrangement of light emitting elements and light receiving elements in a medium conveyance device according to another embodiment.

[0156] 17 , in the medium conveying device according to the present embodiment, a first sensor 217 is used instead of first sensor 117. First sensor 217 includes a light-emitting element 217a, a light-receiving element 217b, a first light-guiding portion 217c, and a second light-guiding portion 217d. The configurations of light-emitting element 217a, light-receiving element 217b, first light-guiding portion 217c, and second light-guiding portion 217d are similar to those of light-emitting element 117a, light-receiving element 117b, first light-guiding portion 117c, and second light-guiding portion 117d of first sensor 117.

[0157] However, the light-emitting element 217a and the first light guiding unit 217c are disposed outside the medium transport path, with the upper guide 107b sandwiched between them. That is, the light-emitting element 217a is disposed to face the upper end of the first light guiding unit 217c and emits light toward the upper end of the first light guiding unit 217c. The first light guiding unit 217c is provided in the upper housing 102 so that its upper end faces the light-emitting element 217a and its lower end faces the upper end of the second light guiding unit 117d across the medium transport path, and guides light emitted from the light-emitting element 217a to the medium transport path. The second light guiding unit 217d is provided in the lower housing 101 so that its upper end faces the lower end of the first light guiding unit 217c across the medium transport path and its lower end faces the light-receiving element 217b, and guides light incident from the medium transport path to the light-receiving element 217b.

[0158] Similarly, the light-emitting element and first light-guiding unit of the second sensor, the third sensor, and / or the fourth sensor may be disposed outside the medium transport path, with upper guide 107b sandwiched between them. Furthermore, in the first sensor, the second sensor, the third sensor, and / or the fourth sensor, the light-receiving element and the second light-guiding unit may be disposed in upper housing 102, and the light-emitting element and the first light-guiding unit may be disposed in lower housing 101. In this case, upper guide 107b is an example of a first guide, and lower guide 107a is an example of a second guide. In these cases, lower guide 107a and upper guide 107b are provided with holes that engage with the ends of the light-guiding units, and lower guide 107a and upper guide 107b are configured so that the reflectance around the holes that engage with the second light-guiding unit is 55% or less. Furthermore, in the first sensor, the second sensor, the third sensor and / or the fourth sensor, the first light guiding section and / or the second light guiding section may be omitted, and the light emitting element and / or the light receiving element may be arranged near the corresponding hole portion.

[0159] As described above in detail, the medium conveying device 100 is now able to detect the medium more accurately using the light-emitting element and the light-receiving element, even when the light-emitting element and the light-receiving element are arranged facing each other across the medium conveying path.

[0160] 18 is a diagram showing a schematic configuration of a processing circuit 270 in a medium conveying device according to yet another embodiment. The processing circuit 270 is used in place of the processing circuit 170 of the medium conveying device 100, and executes a medium reading process. The processing circuit 270 includes a control circuit 271 and a determination circuit 272. Note that each of these components may be configured as an independent integrated circuit, microprocessor, firmware, or the like.

[0161] The control circuit 271 is an example of a control unit, and has the same functions as the control unit 171. The control circuit 271 receives an operation signal from the operation device 105, a medium signal from the medium sensor 111, and a determination result of a medium jam and skew from the determination circuit 272, and controls the motor 151 based on the received signals and the determination result. The control circuit 271 also receives an input image from the imaging device 123, stores it in the storage device 160, and transmits it to the information processing device via the interface device 152.

[0162] The determination circuit 272 is an example of a determination unit, and has the same function as the determination unit 172. The determination circuit 272 receives a first optical signal, a second optical signal, a third optical signal, and a fourth optical signal from the first sensor 117, the second sensor 118, the third sensor 119, and the fourth sensor 122, respectively. The determination circuit 272 determines whether a medium jam or skew has occurred based on the received optical signals, and outputs the determination result to the control circuit 271.

[0163] As described above in detail, even when the media conveying device uses the processing circuit 270, it is possible to more accurately detect the media using the light-emitting element and the light-receiving element, and to appropriately position the light-emitting element and the light-receiving element. [Explanation of symbols]

[0164] 100 medium conveying device, 107a lower guide, 107b upper guide, 112 set guide, 113 movement mechanism, 115 feed roller, 120 first conveying roller, 121 second conveying roller, 117a, 118a, 217a light emitting element, 117b, 118b, 217b light receiving element, 117c, 118c first light guiding section, 117d, 118d second light guiding section, 117e, 118e third light guiding section, 117f, 118f coupling section, 131 substrate, 132a first hole section, 132b second hole section, 132c third hole section, 132d fourth hole section, 135a ninth hole section, 135b tenth hole section, 135c eleventh hole section, 135d twelfth hole section, 138 Light blocking member, 172 judgment unit

Claims

1. A set guide for setting the media, a feeding roller that feeds the medium set in the set guide; a conveying roller that conveys the medium fed by the feeding roller downstream; a moving mechanism disposed downstream of the set guide in the medium transport direction and configured to move the set guide; a guide pair including a first guide provided between the feed roller and the transport roller in the media transport direction and having a first opening and a second opening for detecting the media fed by the feed roller, and a second guide arranged to sandwich the media transport path together with the first guide, and regulating the up-down direction of the media transport path; a light emitting element and a light receiving element disposed on the outside of the medium transport path across the first guide and downstream of the first opening and the second opening so as to be spaced apart from the moving mechanism by a predetermined distance or more in the medium transport direction; a first light guiding portion bent so as to guide the light emitted from the light emitting element to the first opening; a second light guide portion bent so as to guide the light incident from the second opening portion to the light receiving element; A medium transport device comprising:

2. the second guide has a third opening facing the first opening and a fourth opening facing the second opening, The medium transport device according to claim 1 , further comprising a third light guiding section that is provided outside the medium transport path across the second guide and that guides light incident from the third opening to the fourth opening.

3. The medium transport device according to claim 1 , wherein an end of the first light guide portion facing the light emitting element has a lens shape for guiding the light emitted from the light emitting element as parallel light.

4. the first light guiding portion is bent so as to totally reflect light incident parallel to an extension direction of a tube portion provided at least on an end side facing the light emitting element, A medium transport device described in any one of claims 1 to 3, wherein the second light guiding section is bent so as to totally reflect light incident parallel to the extension direction of at least the end side of the tubular section opposite the second opening.

5. a coupling portion that couples the first light guiding portion and the second light guiding portion, 5. The medium transport device according to claim 1, wherein the first opening and the second opening are provided so as to be engageable with the first light guiding portion and the second light guiding portion, respectively.

6. The medium transport device according to claim 5 , wherein the coupling portion is supported on a substrate on which the light emitting element and the light receiving element are mounted.

7. A medium transport device described in any one of claims 1 to 6, further comprising a light-blocking member arranged between the space between the light-emitting element and the first light-guiding section and the space between the second light-guiding section and the light-receiving element.

8. A medium transport device as described in any one of claims 1 to 7, further comprising a second light-emitting element and a second light-receiving element that detect the medium using a fifth opening arranged at a distance from the first opening and the second opening in a direction perpendicular to the medium transport direction.

9. The medium transport device according to claim 8 , further comprising a determination unit that determines whether or not skew of the medium has occurred based on signals output from the light receiving element and the second light receiving element.

10. the first light guiding section is bent at two locations so that a cylindrical portion provided on an end side facing the light emitting element and a cylindrical portion provided on an end side facing the first opening are parallel to each other; A medium transport device as described in any one of claims 1 to 9, wherein the second light guide section is bent at two points so that the tubular section provided on the end side facing the light receiving element and the tubular section provided on the end side facing the second opening are parallel.

Images