Medium transport device

Abstract

To provide a medium conveying device capable of appropriately controlling a guide for restricting contact between a medium and a feed roller while suppressing an increase in power consumption.SOLUTION: A medium transport apparatus includes a feed roller that feeds a medium, a guide that restricts contact between the medium and the feed roller, a movement mechanism for moving the guide, a drive source, and a drive force transmission unit that transmits a drive force for moving the guide from the drive source to the movement mechanism, in which the drive force transmission unit applies a load that restricts transmission of a force from the guide side to the drive source side to the movement mechanism.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a media transport device. [Background technology]

[0002] Generally, media transport devices such as scanners and printers transport media using a feed roller while performing processing such as capturing an image or forming an image on the transported media. In such media transport devices, a guide may be provided to limit contact between the media and the feed roller so that the feed roller does not come into contact with the media before the media is fed.

[0003] A paper feeding device is disclosed that has a set guide that swings between a standby position where it comes into contact with the print-read medium to separate the print-read medium from the set roller, and a paper feeding position where the print-read medium can come into contact with the set roller (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-207944 Summary of the Invention [Problem to be solved by the invention]

[0005] In a medium transport device, it is required to appropriately control a guide that limits contact between a medium and a feed roller while suppressing an increase in power consumption.

[0006] An object of the present invention is to provide a medium transport device that can appropriately control a guide that limits contact between a medium and a feed roller while suppressing an increase in power consumption. [Means for solving the problem]

[0007] A media transport device according to one aspect of the present invention comprises a feed roller for feeding a medium, a guide for limiting contact between the medium and the feed roller, a moving mechanism for moving the guide, a drive source, and a drive force transmission unit for transmitting a drive force for moving the guide from the drive source to the moving mechanism, and the drive force transmission unit applies a load to the moving mechanism that limits the transmission of force from the guide side to the drive source side. [Effects of the Invention]

[0008] According to the present invention, the medium transport device can appropriately control the guide that limits contact between the medium and the feed roller while suppressing an increase in power consumption. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view illustrating a medium transport device according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating a transport path inside the medium transport device. [Figure 3] 10A and 10B are schematic diagrams for explaining a set guide and the like. [Figure 4] FIG. 2 is a schematic diagram for explaining a drive mechanism. [Figure 5] FIG. 2 is a schematic diagram for explaining a drive mechanism. [Figure 6] FIG. 2 is a block diagram showing a schematic configuration of a medium transport device. [Figure 7] FIG. 2 is a diagram showing a schematic configuration of a storage device and a processing circuit. [Figure 8] 10 is a flowchart illustrating an example of the operation of a medium transport process. [Figure 9] FIG. 10 is a schematic diagram for explaining another driving mechanism. [Figure 10] 10A and 10B are schematic diagrams for explaining another driving mechanism. [Figure 11] FIG. 10 is a schematic diagram for explaining another driving mechanism. [Figure 12] FIG. 10 is a schematic diagram for explaining another driving mechanism. [Figure 13] FIG. 10 is a schematic diagram for explaining another medium transport device. [Figure 14] FIG. 10 is a diagram showing a schematic configuration of another processing circuit. DETAILED DESCRIPTION OF THE INVENTION

[0010] 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 described therein, but extends to the inventions set forth in the claims and their equivalents.

[0011] FIG. 1 is a perspective view showing a medium conveying device configured as an image scanner.

[0012] The medium conveying device 100 conveys, captures an image of, and discharges a medium that is an original. The medium may be paper, cardboard, a card, a booklet, a passport, etc. The medium conveying device 100 may also be a facsimile machine, a copier, a multifunction printer (MFP), etc.

[0013] 1, arrow A1 indicates the medium transport direction, arrow A2 indicates the width direction perpendicular to the medium transport direction, and arrow A3 indicates the height direction perpendicular to the medium transport path. Hereinafter, "upstream" refers to the upstream side of the medium transport direction A1, and "downstream" refers to the downstream side of the medium transport direction A1. The width direction A2 is an example of a direction that intersects with the medium transport direction.

[0014] The medium transport device 100 includes a lower housing 101, an upper housing 102, a loading table 103, an ejection table 104, a display operation device 105, and the like.

[0015] The upper housing 102 is disposed in a position that covers the top surface of the medium conveying 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 conveying device 100, for example.

[0016] The mounting table 103 engages with the lower housing 101 and is rotatably provided by a hinge. When the medium conveying device 100 is not in use, the mounting table 103 is positioned to cover the lower housing 101 and the upper housing 102, and functions as an exterior cover. On the other hand, when the medium conveying device 100 is in use, the mounting table 103 is positioned to allow media to be placed thereon, and media to be fed and conveyed are placed on the mounting table 103. The discharge table 104 engages with the lower housing 101 and places discharged media on it. The discharge table 104 may also engage with the upper housing 102 by a hinge or the like.

[0017] The display operation device 105 has a display such as a liquid crystal display, an organic electroluminescence (EL) display, or the like, and an interface circuit for outputting image data to the display, and displays the image data on the display. The display operation device 105 also has a touch panel type input device and an interface circuit for acquiring signals from the input device, accepts operations by a user, and outputs signals according to the user's input. The display device and the operation device may be provided separately.

[0018] FIG. 2 is a diagram for explaining a transport path inside the medium transport device.

[0019] The transport path inside the medium transport device 100 includes a medium sensor 111, a feed roller 112, a separation roller 113, a first transport roller 114, a second transport roller 115, an imaging device 116, a first discharge roller 117, and a second discharge roller 118.

[0020] The number of each of the feed roller 112, separation roller 113, first conveyance roller 114, second conveyance roller 115, first discharge roller 117, and / or second discharge roller 118 is not limited to one, and may be more than one. In this case, the multiple feed rollers 112, separation rollers 113, first conveyance roller 114, second conveyance roller 115, first discharge roller 117, and / or second discharge roller 118 are arranged side by side at intervals in the width direction A2.

[0021] The top surface of the lower housing 101 forms a lower guide 101a of the medium transport path, and the bottom surface of the upper housing 102 forms an upper guide 102a of the medium transport path. As shown in Fig. 2, the medium transport path has a so-called straight path mechanism in which the vertical positional relationship between the front and back surfaces of the medium does not change between the state before transport when the medium is placed on the loading tray 103 and the state after ejection when the medium is placed on the ejection tray 104.

[0022] The media sensor 111 is disposed upstream of the feed roller 112 and the separation roller 113. 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. Note that the media sensor 111 is not limited to a contact detection sensor, and any other sensor capable of detecting the presence or absence of a medium, such as an optical detection sensor, may be used as the media sensor 111.

[0023] The feed roller 112 is provided in the lower housing 101, and separates and feeds the media placed on the mounting table 103, starting from the bottom. The separation roller 113 is a so-called brake roller or retard roller, and is disposed in the upper housing 102 opposite the feed roller 112, and separates the media placed on the mounting table 103. The separation roller 113 is provided so as to be rotatable or stoppable in the direction A5 opposite the medium feeding direction. Note that a separation pad may be used instead of the separation roller 113.

[0024] The first conveying roller 114 and the second conveying roller 115 are disposed facing each other downstream of the feed roller 112 and the separation roller 113 in the medium conveying direction A1. The first conveying roller 114 and the second conveying roller 115 convey the medium fed by the feed roller 112 and the separation roller 113 to the imaging device 116.

[0025] The imaging device 116 captures an image of the medium transported by the first transport roller 114. The imaging device 116 includes a first imaging device 116a and a second imaging device 116b that are arranged opposite each other across the medium transport path.

[0026] The first imaging device 116a has an imaging sensor based on a CIS (Contact Image Sensor) of a life-size optical system having CMOS (Complementary Metal Oxide Semiconductor) imaging elements linearly arranged in the main scanning direction. The first imaging device 116a 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 116a captures images of the surface of the medium being transported, sequentially generating and outputting input images.

[0027] Similarly, the second imaging device 116b has an imaging sensor using a CIS of a 1x1 optical system with CMOS imaging elements arranged linearly in the main scanning direction. The second imaging device 116b 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 116b captures the back side of the medium being conveyed, sequentially generating and outputting line images.

[0028] The medium conveying device 100 may have only one of the first and second imaging devices 116a and 116b, and may read only one side of the medium. Alternatively, a CIS line sensor with a life-size optical system equipped with a CCD (Charge Coupled Device) imaging element may be used as the imaging sensor. Alternatively, a reduction optical system line sensor with a CMOS or CCD imaging element may be used as the imaging sensor.

[0029] The first discharge roller 117 and the second discharge roller 118 are disposed facing each other downstream of the imaging device 116 in the medium conveying direction A1. The first discharge roller 117 and the second discharge roller 118 discharge the medium that has been conveyed by the first conveying roller 114 and the second conveying roller 115 and processed (imaged) by the imaging device 116 onto the discharge tray 104.

[0030] The media placed on the mounting table 103 is transported between the lower guide 101a and the upper guide 102a in the media transport direction A1 by the rotation of the feed roller 112 in the direction of arrow A4 in FIG. 2, i.e., the media feed direction. When feeding the media, the separation roller 113 rotates or stops in the direction of arrow A5, i.e., the opposite direction to the media feed direction. When multiple media are placed on the mounting table 103, the feed roller 112 and the separation roller 113 function to separate only the media placed on the mounting table 103 that are in contact with the feed roller 112. This restricts the transport of media other than the separated media (preventing double feeding).

[0031] The medium is guided by lower guide 101a and upper guide 102a and fed between first conveyor roller 114 and second conveyor roller 115. The medium is fed between first imaging device 116a and second imaging device 116b as first conveyor roller 114 and second conveyor roller 115 rotate in the directions of arrows A6 and A7, respectively. The medium read by imaging device 116 is discharged onto discharge tray 104 as first discharge roller 117 and second discharge roller 118 rotate in the directions of arrows A8 and A9, respectively.

[0032] Figures 3(A) and (B) are schematic diagrams for explaining the set guide, cam member, and arm. Figure 3(A) is a schematic diagram of the set guide, cam member, and arm seen from the side before feeding a medium, and Figure 3(B) is a schematic diagram of the set guide, cam member, and arm seen from the side during feeding a medium.

[0033] As shown in FIGS. 3A and 3B, the medium conveying device 100 further includes a set guide 121, a cam member 122, and an arm 123.

[0034] The set guide 121 is an example of a guide, and is a guide for setting the medium(s) M placed on the placement table 103. As shown in FIG. 3(A), the set guide 121 is rotatably (swingably) supported by the lower housing 101, and is disposed in a position facing the feed roller 112 and the separation roller 113 in the medium transport direction A1 before the medium is fed. When the feeding of the medium M is not being performed, the set guide 121 supports the underside of the medium M placed on the placement table 103, and limits contact between the medium M placed on the placement table 103 and the feed roller 112. Hereinafter, the position where the set guide 121 limits contact between the medium M placed on the placement table 103 and the feed roller 112, as shown in FIG. 3(A), may be referred to as a limiting position. The limiting position is an example of a first position.

[0035] The cam member 122 is an example of a movement mechanism for moving the set guide 121. The cam member 122 is disposed below the set guide 121. The cam member 122 is provided so as to be rotatable (swingable) by a first motor, which will be described later. The cam member 122 is supported by the lower housing 101 so as to be rotatable in accordance with the driving force from the first motor, and when no medium is being fed, the cam member 122 comes into contact with the downstream end of the set guide 121 to hold the set guide 121 in the limit position.

[0036] An elastic member 122a is provided on the cam member 122. The elastic member 122a is a spring member such as a tension coil spring or a torsion coil spring. One end of the elastic member 122a is attached to a frame fixed to the lower housing, and the other end of the elastic member 122a is attached to the cam member 122. The elastic member 122a applies a downward force to the cam member 122.

[0037] The arm 123 is a guide that holds down the uppermost medium of the medium(s) M placed on the placement table 103 from above or prevents the medium from floating up. The arm 123 is pressed downward (toward the set guide 121) by a spring member, rubber member, or the like (not shown). A flap 123a is swingably provided on the arm 123. The flap 123a is a stopper that prevents the medium M from entering the nip portion between the feed roller 112 and the separation roller 113 before the medium is fed. The flap 123a is positioned opposite the set guide 121 in the medium transport direction A1. The flap 123a is an example of a limiting portion that engages with the set guide 121, which is positioned in the limiting position, before the medium is fed, to limit contact between the leading edge of the medium placed on the placement table 103 and the separation roller 113.

[0038] The flap 123a in the medium conveying device 100 prevents the leading edge of the medium from coming into contact with the separation roller 113 before feeding the medium, causing the medium to be lifted up by the separation roller 113 rotating in the opposite direction to the medium feeding direction, thereby preventing the medium from jamming.

[0039] As shown in FIG. 3(B), when feeding of the medium M is performed, the cam member 122 swings (rotates) downward (in the direction of arrow A10) in accordance with the driving force from the first motor and moves away from the downstream end of the set guide 121. When the downstream end of the set guide 121 moves away from the cam member 122 and is no longer held by the cam member 122, the set guide 121 swings downward (in the direction of arrow A11) below the medium transport surface and moves away from the underside of the medium M placed on the mounting table 103. This allows contact between the medium placed on the mounting table 103 and the feed roller 112. Hereinafter, the position shown in FIG. 3(B) where the set guide 121 moves away from the underside of the medium M placed on the mounting table 103 and allows contact between the medium placed on the mounting table 103 and the feed roller 112 is sometimes referred to as the non-restrictive position. The non-restrictive position is an example of the second position. In this way, the set guide 121 is disposed in a limiting position and a non-limiting position, and the cam member 122 moves the set guide 121 between the limiting position and the non-limiting position.

[0040] As described above, the elastic member 122a applies a downward force to the cam member 122. As a result, a load is applied to the cam member 122 by the elastic member 122a in a direction in which the set guide 121 moves from the restricted position to the non-restricted position.

[0041] When the set guide 121 is placed in the non-restrictive position, the flap 123a is disengaged from the set guide 121. As a result, the flap 123a is pushed by the leading edge of the medium M placed on the mounting table 103 and swings downstream (in the direction of arrow A12), allowing the medium M to enter the nip portion between the feed roller 112 and the separation roller 113. In this way, when the set guide 121 is placed in the non-restrictive position, the flap 123a allows the medium M to enter the nip portion between the feed roller 112 and the separation roller 113.

[0042] 4 and 5 are schematic diagrams for explaining the drive mechanism of the feed roller and the cam member. Fig. 4 is a perspective view of the drive mechanism seen from the upstream left side, and Fig. 5 is a perspective view of the drive mechanism seen from the upstream right side.

[0043] As shown in FIGS. 4 and 5, the medium conveying device 100 includes a first motor 130 and a driving force transmission unit 131.

[0044] The first motor 130 is an example of a drive source, and generates a drive force for rotating (oscillating) the feed roller 112 and the cam member 122 in response to a control signal from a processing circuit (described later). The first motor 130 is, for example, a DC (Direct Current) motor. The first motor 130 may be a motor other than a DC motor, such as a stepping motor. The first motor 130 generates a drive force for rotating the feed roller 112 in the medium feed direction A4 and rotating (oscillating) the cam member 122 downward. Either the feed roller 112 or the cam member 122 may be configured to rotate by a drive force generated by a motor other than the first motor 130.

[0045] The driving force transmission unit 131 includes first and second pulleys 132a and 132b, a belt 133, first to fourth gears 134a to 134d, first and second shafts 135a and 135b, a worm 136, a worm wheel 137, a bevel gear 138, and the like.

[0046] A first pulley 132a is attached to the rotating shaft of the first motor 130, and a belt 133 is stretched between the first pulley 132a and the second pulley 132b. A gear portion of the second pulley 132b is engaged with a first gear 134a. The first gear 134a is engaged with a second gear 134b. The second gear 134b is attached to a first shaft 135a, to which the feed roller 112 is further attached. The first shaft 135a functions as the rotating shaft of the feed roller 112. The second gear 134b is further engaged with a third gear 134c. The third gear 134c is engaged with a fourth gear 134d.

[0047] The worm 136 and the worm wheel 137 are an example of a worm gear having a so-called self-locking function. The worm 136 is a cylindrical worm, and a gear is formed on the side of the worm 136. A gear that engages with the fourth gear 134d is formed on one end of the worm 136, and a screw-like gear is formed on the other portion. The worm wheel 137 has helical teeth that engage with the screw-like gear formed on the side of the worm 136. This allows the worm wheel 137 to rotate in conjunction with the rotation of the worm 136. Meanwhile, the lead angle of the groove of the worm 136 is set to a value that prevents rotation from being transmitted from the worm wheel 137 side to the worm 136 side. Therefore, the worm 136 does not rotate in conjunction with the rotation of the worm wheel 137 side, and generates a load that limits the transmission of the force transmitted from the worm wheel 137 to the fourth gear 134d. It should be noted that a helical gear may be used as a member that meshes with the worm 136 instead of the worm wheel 137.

[0048] A bevel gear is formed on one end of the worm wheel 137, and the bevel gear portion of the worm wheel 137 engages with a bevel gear 138. The bevel gear 138 is attached to a second shaft 135b, and a cam member 122 is further attached to the second shaft 135b. The second shaft 135b functions as a rotation axis of the cam member 122. The bevel gear 138 includes a one-way clutch 138a. When the driving force from the first motor 130 causes the bevel gear 138 to rotate in a direction that moves the set guide 121 from the non-restriction position to the restriction position, the one-way clutch 138a transmits the rotational force of the bevel gear 138 to the second shaft 135b. On the other hand, when the driving force from the first motor 130 causes the bevel gear 138 to rotate in a direction that moves the set guide 121 from the restriction position to the non-restriction position, the one-way clutch 138a causes the bevel gear 138 to rotate freely relative to the second shaft 135b.

[0049] The operation of the cam member 122 and the feed roller 112 will now be described.

[0050] When the first motor 130 generates a driving force that rotates in the direction of arrow B1, the first and second pulleys 132a and 132b rotate in the directions of arrows B1 and B2, respectively. As a result, the first to fourth gears 134a to 134d rotate in the directions of arrows B3 to B6, respectively, and the worm 136 and worm wheel 137 rotate in the directions of arrows B7 and B8. Accordingly, the bevel gear 138 rotates in the direction of arrow B9, but the rotational force of the bevel gear 138 is not transmitted to the second shaft 135b by the one-way clutch 138a. However, the second shaft 135b is able to rotate in the direction of arrow B9. Meanwhile, a downward force is applied to the cam member 122 by the elastic member 122a. Therefore, the force from the elastic member 122a causes the cam member 122 to rotate in the direction of arrow B9 (downward direction A10) together with the second shaft 135b, which is the rotation axis of the cam member 122. As a result, the set guide 121 moves from the restricting position to the non-restricting position.

[0051] Furthermore, as a result of the second gear 134b rotating in the direction of arrow B4, the feed roller 112 rotates in the medium feed direction A4 together with the first shaft 135a, which is the rotation axis, by the driving force from the first motor 130. In this manner, the driving force transmission unit 131 transmits the driving force for rotating the feed roller 112 from the first motor 130 to the feed roller 112.

[0052] On the other hand, when the first motor 130 generates a driving force that rotates in the opposite direction of arrow B1, the first and second pulleys 132a-b, the first to fourth gears 134a-d, the worm 136, the worm wheel 137, and the bevel gear 138 rotate in the opposite directions of arrows B1 to B9, respectively. As a result, the cam member 122 rotates upward, and the set guide 121 moves from the non-restricted position to the restricted position. In this way, the driving force transmission unit 131 transmits the driving force for moving the set guide 121 from the first motor 130 to the cam member 122.

[0053] When the cam member 122 moves upward and the set guide 121 is positioned at the limiting position, a downward force is applied to the cam member 122 by the elastic member 122a. As a result, a force is applied to the second shaft 135b to rotate in the direction of arrow B9, and the rotational force of the second shaft 135b is transmitted to the worm wheel 137 via the one-way clutch 138a and the bevel gear 138. However, as described above, the worm 136 does not rotate in response to the rotation from the worm wheel 137 side, and generates a load that limits the transmission of the force transmitted from the worm wheel 137 to the fourth gear 134d. In other words, the driving force transmission unit 131 applies a load to the cam member 122 that limits the transmission of force from the set guide 121 side to the first motor 130 side. In particular, the driving force transmission unit 131 applies a load to the cam member 122 that limits the transmission of force that moves the set guide 121 from the limiting position to the non-limiting position.

[0054] As a result, even if the power supply to the first motor 130 is stopped when the set guide 121 is positioned at the limit position, the set guide 121 will stop at the limit position. Therefore, the medium conveying device 100 can stop the power supply to the first motor 130 before feeding the medium, thereby reducing power consumption. In particular, DC motors are low-cost and their speeds can be easily adjusted, but their detent torque, i.e., their maximum torque when not powered, is low. Therefore, if the first motor 130 is a DC motor, in order to stop the set guide 121 at the limit position using the detent torque of the first motor 130, the reduction ratio of each gear included in the drive mechanism must be extremely large. Extremely large reduction ratios of each gear require a larger mounting area for each gear, resulting in an increase in device size. The medium conveying device 100 reduces power consumption while suppressing an increase in device size by applying a load to the cam member 122 that limits the transmission of force that moves the set guide 121 from the limit position to the non-limit position.

[0055] Furthermore, by using a worm gear, the medium conveying device 100 can apply a load to the cam member 122 that limits the transmission of the force that moves the set guide 121 from the limiting position to the non-limiting position, with a simple and inexpensive configuration. Therefore, the medium conveying device 100 can reduce power consumption while suppressing increases in device cost and size.

[0056] FIG. 6 is a block diagram showing a schematic configuration of the medium transport device.

[0057] In addition to the above-described configuration, the medium conveying device 100 further includes a second motor 151, an interface device 152, a storage device 160, a processing circuit 170, and the like.

[0058] The second motor 151 generates a driving force for rotating the separation roller 113, the first conveyance roller 114, the second conveyance roller 115, the first discharge roller 117, and the second discharge roller 118 in response to a control signal from the processing circuit 170. The second motor 151 is, for example, a DC motor. The second motor 151 may be a motor other than a DC motor, such as a stepping motor. The separation roller 113, the first conveyance roller 114, the second conveyance roller 115, the first discharge roller 117, and / or the second discharge roller 118 may be configured to be driven by the driving force from the first motor 130. The feed roller 112 and / or the cam member 122 may be configured to be driven by the driving force from the second motor 151. The second conveyance roller 115 and the second discharge roller 118 may be driven rollers that rotate following the rotation of the first conveyance roller 114 and the first discharge roller 117, respectively. In addition, the first conveying roller 114, the second conveying roller 115, the first discharge roller 117 and / or the second discharge roller 118 may be configured to rotate by a driving force generated by a motor other than the first motor 130 and the second motor 151.

[0059] 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 personal digital assistant, 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). The communication unit may have a wired communication interface device for transmitting and receiving signals via a wired communication line in accordance with a communication protocol such as a wired LAN.

[0060] 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) or a DVD-ROM (Digital Versatile Disc Read Only Memory). The computer programs may also be distributed from a server or the like and installed into the storage device 160.

[0061] 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.

[0062] The processing circuit 170 is connected to and controls the display operation device 105, the medium sensor 111, the imaging device 116, the first motor 130, the second motor 151, the interface device 152, the storage device 160, etc. Based on the medium signal acquired from the medium sensor 111, the processing circuit 170 performs drive control of the first motor 130 and the second motor 151, image capture control of the imaging device 116, etc. The processing circuit 170 acquires an input image from the imaging device 116 and transmits it to the information processing device via the interface device 152.

[0063] FIG. 7 is a diagram showing a schematic configuration of a storage device and a processing circuit.

[0064] 7, the storage device 160 stores a control program 161, an image acquisition 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 an image acquisition unit 172.

[0065] FIG. 8 is a flowchart illustrating an example of the operation of the medium conveying process of the medium conveying device.

[0066] An example of the operation of the medium conveying process of medium conveying device 100 will be described below with reference to the flowchart shown in Fig. 8. The flow of the operation described below is executed mainly by processing circuit 170 in cooperation with each element of medium conveying device 100 based on a program stored in storage device 160 in advance.

[0067] The control unit 171 controls the first motor 130 to place the set guide 121 in the limit position when the medium conveying device 100 is started up. As a result, the set guide 121 is placed in the limit position before the medium conveying process is performed.

[0068] First, the control unit 171 waits until the user inputs an instruction to read a medium using the display operation device 105 or the information processing device, and an operation signal instructing the reading of a medium is received from the display operation device 105 or the interface device 152 (step S101).

[0069] Next, control unit 171 acquires a medium signal from medium sensor 111, and determines whether or not a medium is placed on mounting table 103 based on the acquired medium signal (step S102). If no medium is placed on mounting table 103, control unit 171 ends the series of steps.

[0070] On the other hand, if a medium is placed on the placement table 103, the control unit 171 controls the first motor 130 and the second motor 151 to place the set guide 121 in the non-restriction position and rotate the rollers to transport the medium (step S103). The control unit 171 rotates the first motor 130 in the direction of arrow B1 in FIGS. 4 and 5 to move the set guide 121 from the restriction position to the non-restriction position and rotates the feed roller 112 in the medium feed direction A4. The control unit 171 also rotates the second motor 151 to rotate the separation roller 113, the first conveyance roller 114, the second conveyance roller 115, the first discharge roller 117, and / or the second discharge roller 118 in the directions of arrows A5 to A9 in FIG. 2, respectively.

[0071] Next, the image acquisition unit 172 causes the imaging device 116 to capture an image of the medium, acquires an input image from the imaging device 116, and outputs the acquired input image by transmitting it to the information processing device via the interface device 152 (step S104).

[0072] Next, control unit 171 determines whether or not a medium remains on mounting table 103 based on the medium signal received from medium sensor 111 (step S105). If a medium remains on mounting table 103, control unit 171 returns the process to step S104 and repeats the processes of steps S104 and S105.

[0073] On the other hand, if there are no media remaining on the mounting table 103, the control unit 171 controls the first motor 130 and the second motor 151 to position the set guide 121 at the limit position and stop the rollers (step S106), thereby ending the series of steps. The control unit 171 rotates the first motor 130 for a certain period of time in the direction opposite to the arrow B1 in FIGS. 4 and 5 to move the set guide 121 from the non-limit position to the limit position. Thereafter, the control unit 171 stops the first motor 130 and stops the feed roller 112. As described above, even if the power supply to the first motor 130 is stopped when the set guide 121 is positioned at the limit position, the set guide 121 will stop at the limit position. The control unit 171 also stops the second motor 151 and stops the separation roller 113, the first conveyance roller 114, the second conveyance roller 115, the first discharge roller 117, and / or the second discharge roller 118.

[0074] As described above in detail, the medium conveying device 100 uses the driving force from the first motor 130 to move the cam member 122, which moves the set guide 121 that limits contact between the medium and the feed roller 112. The medium conveying device 100 imparts a load to the cam member 122 that limits the transmission of force from the cam member 122 to the first motor 130. This allows the medium conveying device 100 to continue to stop the set guide 121 at a position that limits contact between the medium and the feed roller 112, even when the power supply to the first motor 130 is stopped. Therefore, the medium conveying device 100 is able to appropriately control the set guide 121 that limits contact between the medium and the feed roller 112 while suppressing an increase in power consumption.

[0075] 9 is a schematic diagram for explaining a drive mechanism in a medium conveying device according to another embodiment, and is a perspective view of the drive mechanism as seen from above on the upstream side.

[0076] The medium conveying device 200 has the same structure and function as the medium conveying device 100. However, the medium conveying device 200 has a first motor 230 and a driving force transmission unit 231 instead of the first motor 130 and the driving force transmission unit 131.

[0077] The first motor 230 is an example of a drive source, and has the same configuration and function as the first motor 130.

[0078] The driving force transmission section 231 includes first to fourth pulleys 232a to 232d, first and second belts 233a to 233b, first to fifteenth gears 234a to 234o, first to tenth shafts 235a to 235j, a worm 236, a worm wheel 237, a bevel gear 238, and the like.

[0079] A first pulley 232a is attached to the rotary shaft of the first motor 230, and a first belt 233a is stretched between the first pulley 232a and the second pulley 232b. A second belt 233b is stretched between the smaller pulley portion of the second pulley 232b, the third pulley 232c, and the fourth pulley 232d.

[0080] The gear portion of the third pulley 232c is engaged with the first gear 234a. The first gear 234a is attached to the first shaft 235a, and the second discharge roller 118 is further attached to the first shaft 235a. The first shaft 235a functions as the rotation shaft of the second discharge roller 118. The gear portion of the fourth pulley 232d is engaged with the second gear 234b. The second gear 234b is attached to the second shaft 235b, and the second conveyor roller 115 is further attached to the second shaft 235b. The second shaft 235b functions as the rotation shaft of the second conveyor roller 115. The third pulley 232c is attached to the third shaft 235c, and the first discharge roller 117 is further attached to the third shaft 235c. The third shaft 235c functions as the rotation shaft of the first discharge roller 117. The fourth pulley 232d is attached to a fourth shaft 235d, and the fourth shaft 235d is further attached to the first conveyor roller 114. The fourth shaft 235d functions as the rotation axis of the first conveyor roller 114.

[0081] A third gear 234c is further attached to the fourth shaft 235d. The third gear 234c is engaged with the fourth gear 234d. The fourth gear 234d is engaged with the fifth gear 234e. The fifth gear 234e is engaged with the sixth gear 234f. The sixth gear 234f is attached to the fifth shaft 235e, and a seventh gear 234g is further attached to the fifth shaft 235e. The seventh gear 234g is further engaged with an eighth gear 234h. The eighth gear 234h is attached to the sixth shaft 235f, and the feed roller 112 is further attached to the sixth shaft 235f. The sixth shaft 235f functions as a rotation axis of the feed roller 112.

[0082] The fifth gear 234e is further engaged with a ninth gear 234i. The ninth gear 234i is engaged with a tenth gear 234j. The tenth gear 234j is attached to a seventh shaft 235g, to which an eleventh gear 234k is further attached. The eleventh gear 234k is engaged with a twelfth gear 234l. The twelfth gear 234l is engaged with a thirteenth gear 234m. The thirteenth gear 234m is attached to an eighth shaft 235h, to which the separation roller 113 is further attached. The eighth shaft 235h functions as a rotation axis of the separation roller 113.

[0083] The second pulley 232b is attached to a ninth shaft 235i, which further has a fourteenth gear 234n attached thereto. The fourteenth gear 234n is engaged with a fifteenth gear 234o.

[0084] The worm 236 and the worm wheel 237 have the same configuration and function as the worm 136 and the worm wheel 137, respectively. A gear that engages with the fifteenth gear 234o is formed on one end of the worm 236, and a screw-like gear is formed on the other portion. The worm wheel 237 has helical teeth that engage with the screw-like gear formed on the side surface of the worm 236.

[0085] A bevel gear is formed on one end of the worm wheel 237, and the bevel gear portion of the worm wheel 237 is engaged with a bevel gear 238. The bevel gear 238 is attached to a tenth shaft 235j, and a cam member 122 is further attached to the tenth shaft 235j. The tenth shaft 235j functions as a rotation axis of the cam member 122. The bevel gear 238 includes a one-way clutch 238a. When the bevel gear 238 rotates by the driving force from the first motor 230 in a direction that moves the set guide 121 from the non-restriction position to the restriction position, the one-way clutch 238a transmits the rotational force of the bevel gear 238 to the tenth shaft 235j. On the other hand, when the bevel gear 238 rotates by the driving force from the first motor 230 in a direction that moves the set guide 121 from the restriction position to the non-restriction position, the one-way clutch 238a causes the bevel gear 238 to rotate freely relative to the tenth shaft 235j.

[0086] The operation of the cam member 122 and the feed roller 112 will now be described.

[0087] When the first motor 230 generates a driving force that rotates in the direction of arrow C1, the first and second pulleys 232a and 232b rotate in the directions of arrows C1 and C2, respectively. As a result, the fourteenth and fifteenth gears 234n to 234o rotate in the directions of arrows C3 and C4, respectively, and the worm 236 and the worm wheel 237 rotate in the directions of arrows C5 and C6. Accordingly, the bevel gear 238 rotates in the direction of arrow C7, but the rotational force of the bevel gear 238 is not transmitted to the tenth shaft 235j by the one-way clutch 238a. However, the tenth shaft 235j is able to rotate in the direction of arrow C7. Meanwhile, a downward force is applied to the cam member 122 by the elastic member 122a. Therefore, the cam member 122 rotates in the direction of arrow C7 (downward direction A10) together with the tenth shaft 235j, which is the rotation axis, due to the force from the elastic member 122a, thereby moving the set guide 121 from the restricting position to the non-restricting position.

[0088] Furthermore, as the second pulley 232b rotates in the direction of arrow C2, the third pulley 232c and the fourth pulley 232d rotate in the directions of arrows C8 and C9, respectively, and the first gear 234a and the second gear 234b rotate in the directions of arrows C10 and C11, respectively. As a result, the second discharge roller 118 and the second conveyance roller 115 rotate together with the first shaft 235a and the second shaft 235b, which are rotation axes, in the medium conveyance directions A9 and A7 by the driving force from the first motor 230. Furthermore, the first discharge roller 117 and the first conveyance roller 114 rotate together with the third shaft 235c and the fourth shaft 235d, which are rotation axes, in the medium conveyance directions A8 and A6 by the driving force from the first motor 230.

[0089] Furthermore, the third to eighth gears 234c to 234h rotate in the directions of arrows C12 to C17, respectively, and the feed roller 112 rotates in the medium feed direction A4 together with the sixth shaft 235f, which is the rotation axis, by the driving force from the first motor 230. Furthermore, the ninth to thirteenth gears 234i to 234m rotate in the directions of arrows C18 to C22, respectively, and the separation roller 113 rotates in the opposite direction to the medium feed direction A5 together with the eighth shaft 235h, which is the rotation axis, by the driving force from the first motor 230. In this way, the driving force transmission unit 231 transmits the driving force for driving each roller from the first motor 230 to the feed roller 112, separation roller 113, first conveyor roller 114, second conveyor roller 115, first discharge roller 117, and second conveyor roller 115.

[0090] On the other hand, when the first motor 130 generates a driving force that rotates in the opposite direction of the arrow C1, the first and second pulleys 232a-b, the fourteenth and fifteenth gears 234n-o, the worm 236, the worm wheel 237, and the bevel gear 238 rotate in the opposite directions of the arrows C1-C7, respectively. As a result, the cam member 122 rotates upward, and the set guide 121 moves from the non-restricted position to the restricted position. In this way, the driving force transmission unit 231 transmits the driving force for moving the set guide 121 from the first motor 230 to the cam member 122.

[0091] When the cam member 122 moves upward and the set guide 121 is positioned at the limit position, a downward force is applied to the cam member 122 by the elastic member 122a. As a result, a force is applied to the tenth shaft 235j to rotate in the direction of arrow C7, and the rotational force of the tenth shaft 235j is transmitted to the worm wheel 237 via the one-way clutch 238a and the bevel gear 238. However, the worm 236 does not rotate in response to the rotation from the worm wheel 237 side, and generates a load that limits the transmission of the force transmitted from the worm wheel 237 to the fifteenth gear 234o. In other words, the driving force transmission unit 231 applies a load to the cam member 122 that limits the transmission of force from the set guide 121 side to the first motor 230 side. In particular, the driving force transmission unit 231 applies a load to the cam member 122 that limits the transmission of force that moves the set guide 121 from the limit position to the non-limit position. As a result, even if the power supply to the first motor 230 is stopped when the set guide 121 is placed at the limit position, the set guide 121 will stop at the limit position.

[0092] As described above in detail, the medium conveying device 200 is capable of appropriately controlling the set guide 121 that limits contact between the medium and the feed roller 112 while suppressing an increase in power consumption, even when the first motor 230 drives the separation roller 113, the first conveying roller 114, the second conveying roller 115, the first discharge roller 117, and the second conveying roller 115.

[0093] 10A and 10B are schematic diagrams for explaining a drive mechanism in a medium transport device according to yet another embodiment.

[0094] Medium conveying device 300 has the same structure and function as medium conveying device 100 or 200. However, medium conveying device 300 has a cam member 322 and a driving force transmission unit 331 instead of cam member 122 and driving force transmission unit 131 or 231. Cam member 322 and driving force transmission unit 331 have the same structure and function as cam member 122 and driving force transmission unit 131 or 231. However, cam member 322 is provided with an elastic member 322a. Elastic member 322a has the same structure and function as elastic member 122a.

[0095] The driving force transmission unit 331 has a one-way clutch gear 334a, a reduction gear 334b, an idler gear 334c, eleventh and twelfth shafts 335k to 335l, a ratchet gear 339, a ratchet arm 340, and a ratchet sliding spring 341 instead of a worm, a worm wheel, and a bevel gear.

[0096] The one-way clutch gear 334a engages with the fourth gear 134d or the fifteenth gear 234o. The one-way clutch gear 334a is attached to an eleventh shaft 335k, to which a ratchet gear 339 and a cam member 322 are further attached. The eleventh shaft 335k functions as a rotation axis of the cam member 322. When the one-way clutch gear 334a is rotated by the first motor in a direction that moves the set guide 121 from the non-restriction position to the restriction position, the one-way clutch gear 334a transmits rotational force to the eleventh shaft 335k. On the other hand, when the one-way clutch gear 334a is rotated by the first motor in a direction that moves the set guide 121 from the restriction position to the non-restriction position, the one-way clutch gear 334a rotates idly relative to the eleventh shaft 335k.

[0097] Furthermore, the one-way clutch gear 334a engages with a reduction gear 334b. The reduction gear 334b ​​engages with an idler gear 334c. The idler gear 334c is rotatably mounted on a twelfth shaft 335l, which further rotatably mounts a ratchet arm 340. The ratchet arm 340 is arranged such that, when engaged with the ratchet gear 339, it prevents the cam member 322 from rotating in a direction that moves the set guide 121 from the limit position to the non-limit position. However, the ratchet arm 340 is arranged such that, when engaged with the ratchet gear 339, it does not prevent the cam member 322 from rotating in a direction that moves the set guide 121 from the non-limit position to the limit position. The ratchet sliding spring 341 is provided between the idler gear 334c and the ratchet arm 340 so as to come into contact with the idler gear 334c and the ratchet arm 340, and transmits a rotational force from the idler gear 334c to the ratchet arm 340. Note that a torque limiter may be used instead of the ratchet sliding spring 341.

[0098] The operation of the cam member 322 and the feed roller 112 will now be described.

[0099] When the first motor generates a driving force that rotates the feed roller 112 in the medium feed direction A4, the one-way clutch gear 334a rotates in the direction of arrow D1, as shown in FIG. 10A. Accordingly, the reduction gear 334b ​​and the idler gear 334c rotate in the directions of arrows D2 and D3, respectively. When the idler gear 334c rotates in the direction of arrow D3, the ratchet arm 340 rotates in the direction of arrow D4 via the ratchet slide spring 341, and the ratchet arm 340 moves away from the ratchet gear 339. As a result, the ratchet gear 339 is disengaged, and the cam member 322 rotates in the direction of arrow D6 (downward direction A10) together with the eleventh shaft 335k, which is the rotation axis. As a result, the set guide 121 moves from the limit position to the non-limit position.

[0100] On the other hand, when the first motor generates a driving force that rotates the feed roller 112 in the direction opposite to the medium feed direction A4, as shown in FIG. 10B, the one-way clutch gear 334a rotates in the direction of arrow E1. Accordingly, the reduction gear 334b ​​and the idler gear 334c rotate in the directions of arrows E2 and E3, respectively. When the idler gear 334c rotates in the direction of arrow E3, the ratchet arm 340 rotates in the direction of arrow E4 via the ratchet sliding spring 341, and the ratchet arm 340 engages with the ratchet gear 339. However, as described above, the ratchet gear 339 and the ratchet arm 340 do not prevent the cam member 322 from rotating in a direction that moves the set guide 121 from the non-restrictive position to the restrictive position. Therefore, the cam member 322 rotates in the direction of arrow E6 (upward) together with the eleventh shaft 335k, which is the rotation axis. As a result, the set guide 121 moves from the non-restricting position to the restricting position.

[0101] When the cam member 322 moves upward and the set guide 121 is positioned at the limit position, a downward force is applied to the cam member 322 by the elastic member 322a. This applies a force to the eleventh shaft 335k to rotate in the direction opposite to the arrow E5, and the rotational force of the eleventh shaft 335k is transmitted to the ratchet gear 339. However, as described above, the ratchet gear 339 and the ratchet arm 340 prevent the cam member 322 from rotating in a direction that would move the set guide 121 from the limit position to the non-limit position. This causes the ratchet gear 339 and the ratchet arm 340 to generate a load that limits the transmission of the force transmitted from the eleventh shaft 335k to the one-way clutch gear 334a. In other words, the driving force transmission unit 331 applies a load to the cam member 322 that limits the transmission from the set guide 121 side to the first motor side. In particular, the driving force transmission unit 331 applies a load to the cam member 322 that limits the transmission of the force that moves the set guide 121 from the restricted position to the non-restricted position. As a result, even if the power supply to the first motor is stopped while the set guide 121 is positioned at the restricted position, the set guide 121 will stop at the restricted position.

[0102] In particular, the medium conveying device 300 uses the ratchet gear 339, which allows the medium conveying device 300 to apply, with a simple and inexpensive configuration, a load that limits the transmission of the force that moves the set guide 121 from the limiting position to the non-limiting position to the cam member 322. Therefore, the medium conveying device 300 can reduce power consumption while suppressing increases in device cost and size.

[0103] As described above in detail, even when using the ratchet gear 339, the medium conveying device 300 is able to appropriately control the set guide 121 that limits contact between the medium and the feed roller 112 while suppressing an increase in power consumption.

[0104] FIG. 11 is a schematic diagram for explaining a drive mechanism in a medium conveying device according to yet another embodiment.

[0105] The medium conveying device 400 has the same structure and function as the medium conveying device 100 or 200. However, instead of the cam member 122, the first motor 130 or 230, and the drive force transmission unit 131 or 231, the medium conveying device 400 has a cam member 422, a first motor 430, and a drive force transmission unit 431. The cam member 422 has the same structure and function as the cam member 122. However, the cam member 422 is provided with an elastic member 422a. The elastic member 422a has the same structure and function as the elastic member 122a.

[0106] The first motor 430 is an example of a drive source, and has the same configuration and function as the first motor 130 or 230.

[0107] The driving force transmission section 431 includes first and second pulleys 432a and 432b, a belt 433, first to third gears 434a to 434c, a one-way clutch gear 434d, first and second shafts 435a and 435b, a sliding member 441, a pressure member 442, and the like.

[0108] A first pulley 432a is attached to the rotating shaft of the first motor 430, and a belt 433 is stretched between the first pulley 432a and the second pulley 432b. A gear portion of the second pulley 432b is engaged with a first gear 434a. The first gear 434a is engaged with a second gear 434b. The second gear 434b is engaged with a third gear 434c. The third gear 434c is attached to a first shaft 435a, to which the feed roller 112 is further attached. The first shaft 435a functions as the rotation shaft of the feed roller 112. The first gear 434a is engaged with a one-way clutch gear 434d. The one-way clutch gear 434d is attached to a second shaft 435b, to which the cam member 422 is further attached. The second shaft 435b functions as the rotation shaft of the cam member 422. When the one-way clutch gear 434d rotates in a direction to move the set guide 121 from the non-restriction position to the restriction position due to the driving force from the first motor 430, the one-way clutch gear 434d transmits the rotational force to the second shaft 435b. On the other hand, when the one-way clutch gear 434d rotates in a direction to move the set guide 121 from the restriction position to the non-restriction position due to the driving force from the first motor 430, the one-way clutch gear 434d rotates freely relative to the second shaft 435b.

[0109] Sliding member 441 is made of rubber, resin, metal, or the like, and is provided so as to contact first gear 434a, particularly the side surface of first gear 434a, i.e., the surface that intersects with the rotation axis. Sliding member 441 applies a frictional force to first gear 434a that limits the rotation of first gear 434a. As a result, sliding member 441 can efficiently apply a frictional force to first gear 434a and appropriately suppress the rotation of first gear 434a.

[0110] The pressure member 442 is a spring member such as a compression coil spring. The pressure member 442 may be another spring member such as a leaf spring, or a rubber member. One end of the pressure member 442 is attached to the frame 101b fixed to the lower housing 101, and the other end of the pressure member 442 is attached to the surface of the sliding member 441 opposite to the first gear 434a. The pressure member 442 presses the sliding member 441 toward the opposite side of the frame 101b. This allows the medium conveyance device 400 to appropriately suppress the rotation of the first gear 434a.

[0111] It is noted that sliding member 441 may be omitted, and pressure member 442 may directly press first gear 434a. Also, instead of pressure member 442, a fixing member or the like may be provided to fix sliding member 441 at a position where it contacts first gear 434a.

[0112] The force applied to the first gear 434a by the sliding member 441 and / or the pressure applying member 442 is set to be smaller than the force applied to the first gear 434a by the driving force from the first motor 430 and larger than the force applied to the first gear 434a by the elastic member 422a.

[0113] The operation of the cam member 422 and the feed roller 112 will now be described.

[0114] When the first motor 430 generates a driving force that rotates in the direction of arrow F1, the first and second pulleys 432a and 432b rotate in the directions of arrows F1 and F2, respectively. As described above, the force applied to the first gear 434a by the sliding member 441 and / or the pressure applying member 442 is smaller than the force applied to the first gear 434a by the driving force from the first motor 430. Therefore, the first gear 434a rotates in the direction of arrow F3 due to the driving force from the first motor 430. Accordingly, the one-way clutch gear 434d rotates in the direction of arrow F4, but the rotational force of the one-way clutch gear 434d is not transmitted to the second shaft 435b. However, the second shaft 435b is able to rotate in the direction of arrow F4. Meanwhile, a downward force is applied to the cam member 422 by the elastic member 422a. Therefore, the cam member 422 rotates in the direction of arrow F4 (downward direction A10) together with the second shaft 435b, which is the rotation axis, due to the force from the elastic member 422a, thereby moving the set guide 121 from the restricting position to the non-restricting position.

[0115] Furthermore, as the second and third gears 434b and 434c rotate in the directions of arrows F5 and F6, the feed roller 112 rotates in the medium feed direction A4 together with the first shaft 435a, which is the rotation axis, by the driving force from the first motor 430. In this manner, the driving force transmission unit 431 transmits the driving force for rotating the feed roller 112 from the first motor 430 to the feed roller 112.

[0116] On the other hand, when the first motor 430 generates a driving force that rotates in the direction opposite to the arrow F1, the first and second pulleys 432a-b, the first gear 434a, the one-way clutch gear 434d, and the second and third gears 434b-c rotate in the directions opposite to the arrows F1-F6, respectively. As a result, the cam member 422 rotates upward, and the set guide 121 moves from the non-restricted position to the restricted position. In this way, the driving force transmission unit 431 transmits the driving force for moving the set guide 121 from the first motor 430 to the cam member 422.

[0117] When the cam member 422 moves upward and the set guide 121 is positioned at the limiting position, a downward force is applied to the cam member 422 by the elastic member 422a. This applies a force to the second shaft 435b to rotate in the direction of arrow F4, and the rotational force of the second shaft 135b is transmitted to the first gear 434a via the one-way clutch gear 434d. However, as described above, the force applied to the first gear 434a by the sliding member 441 and / or the pressure applying member 442 is greater than the force applied to the first gear 434a by the elastic member 422a. In other words, the driving force transmitting unit 431 applies a load to the cam member 422 that limits the transmission of power from the set guide 121 side to the first motor 430 side. In particular, the driving force transmitting unit 431 applies a load to the cam member 422 that limits the transmission of power that moves the set guide 121 from the limiting position to the non-limiting position. As a result, even if the power supply to the first motor 430 is stopped when the set guide 121 is placed at the limit position, the set guide 121 will stop at the limit position.

[0118] Furthermore, by using the sliding member 441 and / or the pressure member 442, the medium conveying device 400 can, with a simple and inexpensive configuration, apply to the cam member 422 a load that limits the transmission of the force that moves the set guide 121 from the restricting position to the non-restricting position. Therefore, the medium conveying device 100 can reduce power consumption while suppressing increases in device cost and size.

[0119] As described above in detail, even when the medium conveying device 400 uses the sliding member 441 and / or the pressure member 442, it is possible to appropriately control the set guide 121 that limits contact between the medium and the feed roller 112 while suppressing an increase in power consumption.

[0120] FIG. 12 is a schematic diagram for explaining a drive mechanism in a medium conveying device according to yet another embodiment.

[0121] Medium conveying device 500 has the same structure and function as medium conveying device 400. However, medium conveying device 500 has driving force transmission unit 531 instead of driving force transmission unit 431. Driving force transmission unit 531 has the same structure and function as driving force transmission unit 431. However, driving force transmission unit 531 has torque limiter 543 instead of sliding member 441 and / or pressure member 442.

[0122] The torque limiter 543 is attached to the first gear 434a and fixed to a frame 101b fixed to the lower housing 101. The torque limiter 543 is set so that when the driving force of the first motor 430 is transmitted to the first gear 434a, the first gear 434a rotates, and when only the force of the elastic member 422a is transmitted to the first gear 434a, the first gear 434a stops.

[0123] The operation of the cam member 422 and the feed roller 112 will now be described.

[0124] When the first motor 430 generates a driving force that rotates in the direction of arrow F1, the first and second pulleys 432a and 432b rotate in the directions of arrows F1 and F2, respectively. As described above, the torque limiter 543 is set so that when the driving force from the first motor 430 is transmitted to the first gear 434a, the first gear 434a rotates. Therefore, the driving force from the first motor 430 rotates the first gear 434a in the direction of arrow F3. As a result, similar to the case of the medium conveying device 400, the set guide 121 moves from the limiting position to the non-limiting position, and the feed roller 112 rotates in the medium feed direction A4.

[0125] On the other hand, when the first motor 430 generates a driving force that rotates in the direction opposite to the arrow F1, the set guide 121 moves from the non-restricted position to the restricted position.

[0126] When the cam member 422 moves upward and the set guide 121 is positioned at the limiting position, a downward force is applied to the cam member 422 by the elastic member 422a. This applies a force to the second shaft 435b to rotate in the direction of arrow F4, and the rotational force of the second shaft 135b is transmitted to the first gear 434a via the one-way clutch gear 434d. However, as described above, the torque limiter 543 is configured so that the first gear 434a stops when only the force from the elastic member 422a is transmitted to the first gear 434a. In other words, the driving force transmission unit 531 applies a load to the cam member 422 that limits transmission of force from the set guide 121 side to the first motor 430 side. In particular, the driving force transmission unit 531 applies a load to the cam member 422 that limits transmission of force that moves the set guide 121 from the limiting position to the non-limiting position. As a result, even if the power supply to the first motor 430 is stopped when the set guide 121 is placed at the limit position, the set guide 121 will stop at the limit position.

[0127] Furthermore, by using the torque limiter 543, the medium conveying device 500 can, with a simple and inexpensive configuration, apply to the cam member 422 a load that limits the transmission of the force that moves the set guide 121 from the limiting position to the non-limiting position. Therefore, the medium conveying device 500 can reduce power consumption while suppressing increases in device cost and size.

[0128] As described above in detail, even when using the torque limiter 543, the medium conveying device 500 is able to appropriately control the set guide 121 that limits contact between the medium and the feed roller 112 while suppressing an increase in power consumption.

[0129] FIG. 13 is a schematic diagram for explaining a medium transport device according to still another embodiment.

[0130] The medium conveying device 600 has the same structure and function as the medium conveying devices 100 to 500. However, the medium conveying path of the medium conveying device 600 has a so-called U-turn path mechanism, and feeds and conveys the media placed on the placement table 103 in order from the top, and discharges them onto the discharge table 104. Instead of the feed roller, separation roller, set guide, cam member, elastic member, arm, and flap that the medium conveying devices 100 to 500 have, the medium conveying device 600 has a feed roller 612, a separation roller 613, a set guide 621, a cam member 622, an elastic member 622a, an arm 623, and a flap 623a. The feed roller 612, separation roller 613, set guide 621, cam member 622, elastic member 622a, arm 623 and flap 623a have the same configuration and function as the feed roller, separation roller, set guide, cam member, elastic member, arm and flap of the media conveying devices 100 to 500, respectively.

[0131] However, the feed roller 612 is disposed above the separation roller 613. The set guide 621, cam member 622, and elastic member 622a are disposed above the medium transport path, and the arm 623 is disposed below the medium transport path. The elastic member 622a applies an upward force to the cam member 622. In other words, the feed roller 612, separation roller 613, set guide 621, cam member 622, elastic member 622a, arm 623, and flap 623a are disposed upside down with respect to the feed roller, separation roller, set guide, cam member, elastic member, arm, and flap that the medium transport devices 100 to 500 have, respectively.

[0132] As described above in detail, the medium conveying device 600 is now able to appropriately control the set guide 621 to limit contact between the medium and the feed roller 612 while suppressing an increase in power consumption, even when the set guide 621 is positioned above the medium conveying path.

[0133] FIG. 14 is a diagram showing a schematic configuration of a processing circuit in a medium conveying device according to yet another embodiment.

[0134] The processing circuit 770 is used in place of the processing circuit 170 and executes media reading processing and the like in place of the processing circuit 170. The processing circuit 770 includes a control circuit 771 and an image acquisition circuit 772. Note that these may each be configured as an independent integrated circuit, microprocessor, firmware, or the like.

[0135] The control circuit 771 is an example of a control unit, and has the same functions as the control unit 171. The control circuit 771 receives an operation signal from the display operation device 105 or the interface device 152, and a medium signal from the medium sensor 111. The control circuit 771 controls the first motor 130 and the second motor 151 based on the received information.

[0136] The image acquisition circuit 772 is an example of an image acquisition unit, and has the same function as the image acquisition unit 172. The image acquisition circuit 772 acquires an input image from the imaging device 116 and outputs it to the interface device 152.

[0137] As described above in detail, even when using the processing circuit 770, the medium conveying device is able to appropriately control the set guide 621, which limits contact between the medium and the feed roller 612, while suppressing an increase in power consumption.

[0138] Although preferred embodiments have been described above, the embodiments are not limited to these. For example, the medium transport device may have an image forming device instead of or in addition to the imaging device 116. The image forming device is an inkjet type, laser type, or other printer, and is arranged at a position corresponding to the position at which the imaging device 116 is arranged, and forms an image (prints predetermined information) on the transported medium. [Explanation of symbols]

[0139] 100, 200, 300, 400, 500, 600 medium conveying device, 112, 612 feeding roller, 113, 613 separation roller, 121, 621 set guide, 122, 322, 422, 622 cam member, 122a, 322a, 422a, 622a elastic member, 123a, 623a flap, 130, 230, 430 first motor, 131, 231, 331, 431, 531 driving force transmission unit, 136, 236 worm, 137, 237 worm wheel, 339 ratchet gear, 441 sliding member, 442 pressure member, 543 torque limiter

Claims

1. a feeding roller for feeding the medium; a guide that limits contact between the medium and the feed roller; a movement mechanism for moving the guide; A driving source; a driving force transmission unit that transmits a driving force for moving the guide from the driving source to the movement mechanism, the driving force transmission unit applies a load to the movement mechanism that limits the transmission of force from the guide side to the driving source side; A medium transport device characterized by:

2. the guide is disposed at a first position that limits contact between the medium and the feed roller and at a second position that allows contact between the medium and the feed roller; the moving mechanism moves the guide between the first position and the second position; The medium transport device according to claim 1 , wherein the driving force transmission unit applies a load to the movement mechanism that limits transmission of a force that moves the guide from the first position to the second position.

3. The medium transport device according to claim 1 , wherein the driving force transmission unit includes a worm gear including a worm and a worm wheel.

4. The medium transport device according to claim 1 , wherein the drive force transmission unit includes a ratchet gear.

5. The medium transport device according to claim 1 , wherein the driving force transmission unit includes a pressure member.

6. The medium transport device according to claim 1 , wherein the driving force transmission unit includes a sliding member.

7. The medium transport device according to claim 1 , wherein the driving force transmission unit includes a torque limiter.

8. A mounting table; a separation roller disposed opposite the feeding roller; 3. The media transport device of claim 2, further comprising a limiting portion that engages with the guide positioned at the first position before feeding the media and limits contact between the leading edge of the media placed on the loading table and the separation roller.

9. The medium transport device according to claim 2 , further comprising an elastic member that applies a load to the movement mechanism in a direction in which the guide moves from the first position to the second position.

10. The medium transport device according to claim 1 , wherein the drive source is a DC motor.

Images