Medium feeding device, medium feeding method, and control program

Abstract

To provide a medium feeding device, a medium feeding method, and a control program capable of appropriately feeding a medium.SOLUTION: The medium feeding device includes a feed roller that feeds a medium, a drive source that generates a drive force for driving the feed roller, a control unit that controls the drive source, the control unit being capable of controlling the drive source to stop the feed roller, and an applying unit that applies a load to rotation of the feed roller. In the medium feeding device, when the control unit drives the drive source to stop the feed roller, the feed roller does not rotate in the direction opposite to the medium feeding direction due to the load applied by the applying unit.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a medium feeding device, a medium feeding method, and a control program. [Background technology]

[0002] 2. Description of the Related Art Generally, a medium feeding device such as a scanner or printer feeds a medium using a feeding roller while performing processing such as imaging or image formation on the fed medium.

[0003] A document feeder is disclosed in which a compression spring is provided as a rotation restriction means to bias the paper feed roller gear in the axial direction of the paper feed roller shaft (see Patent Document 1). In this document feeder, the compression spring is provided between the paper feed roller gear and the bearing of the paper feed roller shaft, so that even if the paper feed roller is biased to rotate in the negative direction, the paper feed roller gear is prevented from rotating in the negative direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 209174 Summary of the Invention [Problem to be solved by the invention]

[0005] It is required that a media feeding device be able to feed media appropriately.

[0006] An object of the present invention is to provide a medium feeding device, a medium feeding method, and a control program that are capable of feeding a medium appropriately. [Means for solving the problem]

[0007] A medium feeding device according to one aspect of the present invention includes a feed roller for feeding a medium, a drive source for generating a drive force for driving the feed roller, a control unit for controlling the drive source, the control unit being capable of controlling the drive source to stop the feed roller, and an application unit for applying a load to the rotation of the feed roller.

[0008] A medium feeding device according to one aspect of the present invention is a medium feeding device comprising a feed roller for feeding a medium, a drive source for generating a drive force for driving the feed roller, a control unit for controlling the drive source, and an application unit for applying a load to the rotation of the feed roller, wherein when the control unit drives the drive source to stop the feed roller, the load applied by the application unit prevents the feed roller from rotating in the direction opposite to the medium feeding direction.

[0009] A media feeding method according to one aspect of the present invention feeds a medium using a feed roller, generates a driving force for driving the feed roller using a drive source, and applies a load to the rotation of the feed roller using an application unit, controlling the drive source so that the feed roller can be stopped.

[0010] A control program according to one aspect of the present invention is a control program for a medium feeding device having a feed roller for feeding a medium, a drive source for generating a drive force for driving the feed roller, and an application unit for applying a load to the rotation of the feed roller, and causes the medium feeding device to control the drive source so that the feed roller can be stopped. [Effects of the Invention]

[0011] According to the present invention, the medium feeding device, the medium feeding method, and the control program are capable of feeding the medium appropriately. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view illustrating a medium feeding device according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating a transport path inside the medium feeding device. [Figure 3] FIG. 4 is a schematic diagram for explaining a drive mechanism of a feed roller. [Figure 4] FIG. 10 is a schematic diagram for explaining an adding unit. [Figure 5] FIG. 10 is a schematic diagram for explaining an adding unit. [Figure 6] FIG. 3 is a schematic diagram for explaining the circuit configuration of a first motor. [Figure 7] FIG. 2 is a block diagram showing a schematic configuration of a medium feeding device. [Figure 8] FIG. 2 is a diagram showing a schematic configuration of a storage device and a processing circuit. [Figure 9] 10 is a flowchart illustrating an example of the operation of a medium reading process. [Figure 10] 1(A) to 1(C) are schematic diagrams showing the state of the medium. [Figure 11] FIG. 10(A) is a schematic diagram showing the relationship between the second gear and the third gear, and FIG. 10(B) is a schematic diagram showing the relationship between the second gear and the third gear in another medium feeding device. [Figure 12] 10A and 10B are schematic diagrams illustrating the state of media in another medium feeding device. [Figure 13] FIG. 10 is a diagram showing a schematic configuration of another processing circuit. DETAILED DESCRIPTION OF THE INVENTION

[0013] A medium feeding 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.

[0014] FIG. 1 is a perspective view showing a medium feeding device configured as an image scanner.

[0015] The medium feeding 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 feeding device 100 may be a facsimile machine, a copier, a multifunction printer (MFP), etc.

[0016] 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.

[0017] The medium feeding 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.

[0018] The upper housing 102 is positioned to cover the top surface of the medium feeding device 100, and is engaged with the lower housing 101 by a hinge so that it can be opened and closed when the medium is jammed or when cleaning the inside of the medium feeding device 100.

[0019] The loading platform 103 engages with the lower housing 101 and is rotatably provided by a hinge. When the medium feeding device 100 is not in use, the loading platform 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 feeding device 100 is in use, the loading platform 103 is positioned to allow media to be placed thereon, and media to be fed and transported is placed on the loading platform 103. The ejection platform 104 engages with the lower housing 101 and places ejected media on it. The ejection platform 104 may also engage with the upper housing 102 by a hinge or the like.

[0020] 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.

[0021] FIG. 2 is a diagram for explaining a transport path inside the medium feeding device.

[0022] The transport path inside the media feeding device 100 includes a first media sensor 111, a feeding roller 112, a separation roller 113, a first transport roller 114, a second transport roller 115, a second media sensor 116, an imaging device 117, a first discharge roller 118, and a second discharge roller 119.

[0023] The number of each of the feed roller 112, separation roller 113, first conveyance roller 114, second conveyance roller 115, first discharge roller 118, and / or second discharge roller 119 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 118, and / or second discharge roller 119 are arranged side by side at intervals in the width direction A2.

[0024] 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.

[0025] The first medium sensor 111 is disposed upstream of the feed roller 112 and the separation roller 113. The first medium sensor 111 has a contact detection sensor and detects whether or not a medium is placed on the placement table 103. The first medium sensor 111 generates and outputs a first medium signal whose signal value changes depending on whether or not a medium is placed on the placement table 103. Note that the first medium sensor 111 is not limited to a contact detection sensor, and any other sensor capable of detecting the presence or absence of a medium, such as an optical detection sensor, may be used as the first medium sensor 111.

[0026] 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.

[0027] 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 117.

[0028] The second media sensor 116 is positioned downstream of the first transport rollers 114 and the second transport rollers 115 and upstream of the imaging device 117, and detects the leading and trailing edges of a medium transported to that position. The second media sensor 116 includes a light emitter and a light receiver provided on one side of the medium transport path, and a light guide member provided opposite the light emitter and light receiver across the medium transport path. The light guide member is a light guide tube such as a U-shaped prism. The light emitter is an LED (Light Emitting Diode) or the like, and emits light toward the transport path. On the other hand, the light receiver is a photodiode or the like, and receives light emitted by the light emitter and guided by the light guide member. When a medium is present in a position opposite the second media sensor 116, the light emitted from the light emitter is blocked by the medium, and the light receiver does not detect the light emitted from the light emitter. The light receiver generates and outputs a second medium signal whose signal value changes depending on whether a medium is present or not at the position of the second medium sensor 116, based on the intensity of the received light.

[0029] A reflective member such as a mirror may be used instead of the light-guiding member. The light emitter and the light receiver may be positioned opposite each other across the transport path. Second medium sensor 116 may detect the presence of a medium using a contact detection sensor that passes a predetermined current when the medium is in contact or when the medium is not in contact.

[0030] The imaging device 117 captures an image of the medium transported by the first transport roller 114. The imaging device 117 includes a first imaging device 117a and a second imaging device 117b that are arranged opposite each other across the medium transport path.

[0031] The first imaging device 117a has an imaging sensor based on a CIS (Contact Image Sensor) of a 1:1 optical system type having imaging elements based on CMOS (Complementary Metal Oxide Semiconductor) linearly arranged in the main scanning direction. The first imaging device 117a 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 117a captures images of the surface of the medium being transported, sequentially generating and outputting input images.

[0032] Similarly, the second imaging device 117b 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 117b 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 117b captures the back side of the medium being conveyed, sequentially generating and outputting line images.

[0033] Note that medium feeding device 100 may have only one of first imaging device 117a and second imaging device 117b disposed, and may read only one side of the medium. Also, 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. Also, a reduction optical system line sensor with a CMOS or CCD imaging element may be used as the imaging sensor.

[0034] The first discharge roller 118 and the second discharge roller 119 are disposed facing each other downstream of the imaging device 117 in the medium conveying direction A1. The first discharge roller 118 and the second discharge roller 119 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 117 onto the discharge tray 104.

[0035] 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).

[0036] 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 117a and second imaging device 117b 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 117 is discharged onto discharge tray 104 as first discharge roller 118 and second discharge roller 119 rotate in the directions of arrows A8 and A9, respectively.

[0037] 3 is a schematic diagram for explaining the drive mechanism of the feed roller, and is a perspective view of the drive mechanism as seen from the upstream left side.

[0038] As shown in FIG. 3, the medium feeding device 100 includes a first motor 130 and a driving force transmission unit 131.

[0039] The first motor 130 is an example of a drive source, and generates a drive force for driving the feed roller 112 in response to a control signal from a processing circuit (described later). The first motor 130 is, for example, a DC (Direct Current) motor. By using a DC motor as the first motor 130, the medium feeding device 100 can reduce component costs and power consumption. 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 feeding direction A4.

[0040] The driving force transmission unit 131 includes first and second pulleys 132a and 132b, a belt 133, first to third gears 134a to 134c, a shaft 135, an applying unit 136, and the like.

[0041] 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. The 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 engaged with a third gear 134c. The third gear 134c is attached to a shaft 135, and the feed roller 112 and an application unit 136 are further attached to the shaft 135. The shaft 135 functions as the rotation axis of the feed roller 112.

[0042] The feed roller 112 includes a one-way clutch 112a. The one-way clutch 112a is provided between the feed roller 112 and the shaft 135. When the feed roller 112 rotates in the medium feed direction A4 by the driving force from the first motor 130, the one-way clutch 112a transmits the rotational force of the shaft 135 to the feed roller 112. On the other hand, when the feed roller 112 rotates in the medium feed direction A4 accompanied by the fed medium, the one-way clutch 112a does not transmit the rotational force of the feed roller 112 to the shaft 135, causing the feed roller 112 to rotate freely relative to the shaft 135.

[0043] The applying unit 136 applies a load for the rotation of the feed roller 112 to the driving force transmitting unit 131, particularly to the third gear 134c and the shaft 135.

[0044] The operation of the feed roller 112 will now be described.

[0045] 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. This causes the first to third gears 134a to 134c to rotate in the directions of arrows B3 to B5, respectively. As a result, the feed roller 112 rotates in the medium feed direction A4 together with the shaft 135, which is the rotation axis, by the driving force from the first motor 130. In this way, the driving force transmission unit 131, which includes the first and second pulleys 132a and 132b, the belt 133, the first to third gears 134a to 134c, and the shaft 135, transmits the driving force for rotating the feed roller 112 from the first motor 130 to the feed roller 112.

[0046] 4 and 5 are schematic diagrams for explaining the application unit. Fig. 4 is a perspective view of the shaft, the feed roller, and the application unit as seen from the downstream side. Fig. 5 is a cross-sectional view of the shaft, the feed roller, and the application unit.

[0047] As shown in FIGS. 4 and 5, the applying portion 136 includes a support member 137, a contact member 138, and a pressing member 139.

[0048] Support member 137 is a bearing for shaft 135. Support member 137 has engagement portion 137a. Engagement of engagement portion 137a with a frame (not shown) provided on lower housing 101 fixes support member 137 to lower housing 101. In this way, support member 137 supports shaft 135 so as to fix the position of shaft 135 relative to lower housing 101.

[0049] The abutment member 138 is a bearing for the shaft 135 and is disposed between the support member 137 and the third gear 134c. The abutment member 138 is formed of rubber, resin, metal, or the like, and is disposed so as to come into contact with the third gear 134c. In particular, the abutment member 138 is disposed so as to come into contact with the side surface of the third gear 134c, i.e., the surface that intersects with the rotation axis. The abutment member 138 applies a frictional force to the third gear 134c that limits the rotation of the third gear 134c.

[0050] The frictional force applied to the third gear 134c by the abutment member 138 is set to be smaller than the driving force applied to the third gear 134c by the first motor 130. As a result, when the second gear 134b rotates due to the driving force from the first motor 130, the third gear 134c rotates in accordance with the rotation of the second gear 134b. On the other hand, the frictional force applied to the third gear 134c by the abutment member 138 is set to be larger than the frictional force generated by the one-way clutch 112a of the feed roller 112. As a result, when the shaft 135 tries to rotate due to the frictional force of the one-way clutch 112a, the third gear 134c does not rotate due to the frictional force of the abutment member 138.

[0051] The pressing member 139 is a spring member such as a compression coil spring. The pressing member 139 may be another spring member such as a leaf spring, or a rubber member. The pressing member 139 is disposed along the shaft 135 between the support member 137 and the abutment member 138. One end of the pressing member 139 is attached to the support member 137 fixed to the lower housing 101, and the other end of the pressing member 139 is attached to the surface of the abutment member 138 opposite to the third gear 134c. The pressing member 139 presses the abutment member 138 toward the third gear 134c. Accordingly, the abutment member 138 presses the third gear 134c in the rotation axis direction, applying a frictional force to the third gear 134c that limits the rotation of the third gear 134c.

[0052] As a result, the applying unit 136 applies the load against the rotation of the feed roller 112 to the driving force transmission unit 131 including the third gear 134c and the shaft 135. By pressing the third gear 134c in the direction of the rotation axis, the applying unit 136 efficiently applies a frictional force to the third gear 134c, and can appropriately suppress the rotation of the feed roller 112.

[0053] Note that support member 137 may be omitted, and pressing member 139 may be provided so as to come into direct contact with a frame (not shown) provided on lower housing 101. Also, contact member 138 may be omitted, and pressing member 139 may be provided so as to come into direct contact with third gear 134c. Also, instead of pressing member 139, a fixing portion or the like may be provided to fix contact member 138 at a position where it comes into contact with third gear 134c.

[0054] FIG. 6 is a schematic diagram for explaining the circuit configuration of the first motor.

[0055] As shown in Fig. 6, the circuit inside the first motor 130 includes a first motor section 130a and a first resistor section 130b. The first motor section 130a rotates in response to the voltage applied to or current flowing into terminals on both sides. The first resistor section 130b is a variable resistor. The first resistor section 130b may also be a fixed resistor. The first resistor section 130b may also be provided so as to be short-circuitable.

[0056] FIG. 7 is a block diagram showing a schematic configuration of the medium feeding device.

[0057] In addition to the above-described components, the medium feeding device 100 further includes a second motor 141, an interface device 142, a storage device 150, a processing circuit 160, and the like.

[0058] The second motor 141 is an example of a second drive source. The second motor 141 generates a drive force for rotating the separation roller 113, the first conveyance roller 114, the second conveyance roller 115, the first discharge roller 118, and the second discharge roller 119 in response to a control signal from the processing circuit 160. The second motor 141 is, for example, a DC motor. By using a DC motor as the second motor 141, the medium feeding device 100 can reduce component costs and power consumption. The second motor 141 may be a motor other than a DC motor, such as a stepping motor.

[0059] The separation roller 113, the first conveyor roller 114, the second conveyor roller 115, the first discharge roller 118, and / or the second discharge roller 119 may be provided so as to be driven by a driving force from a first motor 130. Furthermore, the feed roller 112 may be provided so as to be driven by a driving force from a second motor 141. Note that the second conveyor roller 115 and the second discharge roller 119 may be driven rollers that rotate following the first conveyor roller 114 and the first discharge roller 118, respectively. Furthermore, the first conveyor roller 114, the second conveyor roller 115, the first discharge roller 118, and / or the second discharge roller 119 may be provided so as to rotate by a driving force generated by a motor other than the first motor 130 and the second motor 141.

[0060] The interface device 142 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 142, 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.

[0061] The storage device 150 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 150 also stores computer programs, databases, tables, and the like used for various processes of the medium feeding device 100. The computer programs may be installed into the storage device 150 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 150.

[0062] The processing circuit 160 operates based on a program stored in advance in the storage device 150. The processing circuit is, for example, a CPU (Central Processing Unit). The processing circuit 160 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.

[0063] The processing circuit 160 is connected to and controls the display operation device 105, the first medium sensor 111, the second medium sensor 116, the imaging device 117, the first motor 130, the second motor 141, the interface device 142, the storage device 150, etc. The processing circuit 160 performs drive control of the first motor 130 and the second motor 141, image capture control of the imaging device 117, etc., based on the first medium signal acquired from the first medium sensor 111 and the second medium signal acquired from the second medium sensor 116. The processing circuit 160 acquires an input image from the imaging device 117 and transmits it to the information processing device via the interface device 142.

[0064] FIG. 8 is a diagram showing a schematic configuration of a storage device and a processing circuit.

[0065] 8, the storage device 150 stores a control program 151, an image acquisition program 152, and the like. Each of these programs is a functional module implemented by software running on a processor. The processing circuitry 160 reads each program stored in the storage device 150 and operates in accordance with the read program. As a result, the processing circuitry 160 functions as a control unit 161 and an image acquisition unit 162.

[0066] FIG. 9 is a flowchart showing an example of the operation of the medium reading process of the medium feeding device.

[0067] An example of the operation of the medium reading process of medium feeding device 100 will be described below with reference to the flowchart shown in Figure 9. The flow of the operation described below is executed mainly by processing circuit 160 in cooperation with each element of medium feeding device 100 based on a program stored in memory device 150 in advance.

[0068] First, the control unit 161 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 142 (step S101).

[0069] Next, control unit 161 acquires a medium signal from first 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 161 ends the series of steps.

[0070] On the other hand, when a medium is placed on the placement table 103, the control unit 161 controls the first motor 130 to rotate the feed roller 112. The control unit 161 also controls the second motor 141 to rotate the separation roller 113, the first conveyance roller 114, the second conveyance roller 115, the first discharge roller 118, and / or the second discharge roller 119 (step S103). In this way, the control unit 161 feeds and conveys the medium.

[0071] FIG. 10A is a schematic diagram showing the state of the medium immediately after feeding begins.

[0072] 10(A), the feed roller 112 rotates in the medium feed direction A4 to feed the lowest medium M1 among the media placed on the mounting table 103. Furthermore, the separation roller 113 rotates in the direction A5 opposite to the medium feed direction, so that the media placed on the mounting table 103 other than medium M1 remain on the mounting table 103 without being fed.

[0073] Next, the control unit 161 waits until the leading edge of the fed medium passes the first conveyor roller 114 and the second conveyor roller 115 (step S104). For example, the control unit 161 periodically acquires a second medium signal from the second medium sensor 116. The control unit 161 determines that the leading edge of the medium has passed the first conveyor roller 114 and the second conveyor roller 115 when the signal value of the second medium signal changes from a value indicating that the medium is not present to a value indicating that the medium is present.

[0074] Next, the control unit 161 controls the first motor 130 to stop the feed roller 112 (step S105). The control unit 161 sets the voltage applied to the terminals on both sides of the first motor unit 130a or the current flowing into the first motor unit 130a so that the rotation speed of the feed roller 112 becomes zero. That is, the control unit 161 applies a predetermined voltage to the first motor 130 and causes a predetermined current to flow, thereby controlling the first motor 130 to stop the feed roller 112. The predetermined current is a current equivalent to the hold current of a stepping motor. In this way, after stopping the feed roller 112, the control unit 161 can maintain the drive force transmission unit 131 of the feed roller 112 in a stopped state.

[0075] In particular, when the feed roller 112 comes into contact with the separation roller 113, which rotates in the direction A5 opposite to the medium feed direction, the control unit 161 controls the first motor 130 so that the feed roller 112 is not rotated by the separation roller 113. As a result, when the trailing edge of the medium being fed passes through the nip portion between the feed roller 112 and the separation roller 113, the feed roller 112 and the separation roller 113 come into contact with each other and stop.

[0076] The control unit 161 may control the first motor 130 to stop the feed roller 112 by short-circuiting the terminals on both sides of the first motor unit 130a. In this case, the control unit 161 can also keep the drive force transmission unit 131 of the feed roller 112 stopped after stopping the feed roller 112.

[0077] In this way, the control unit 161 can control the first motor 130 to stop the feed roller 112. That is, the control unit 161 controls the first motor 130 to stop the feed roller 112. In particular, the control unit 161 controls the first motor 130 to stop the feed roller 112 after the leading edge of the medium has passed the first conveyor roller 114 and the second conveyor roller 115.

[0078] FIG. 10B is a schematic diagram showing the state of the medium immediately after the leading edge has passed through first conveyor roller 114 and second conveyor roller 115. As shown in FIG.

[0079] 10(B), after the leading edge of the medium passes the first conveyance roller 114 and the second conveyance roller 115, the feed roller 112 stops, and thereafter the medium M1 is conveyed by the first conveyance roller 114 and the second conveyance roller 115. The feed roller 112 is rotated in the medium conveyance direction A4 by the medium M1 conveyed by the first conveyance roller 114 and the second conveyance roller 115. When the feed roller 112 stops, the medium M1 is pushed by the feed roller 112, and is deflected between the feed roller 112 and the first conveyance roller 114 and the second conveyance roller 115, which prevents the medium from jamming.

[0080] Next, the image acquisition unit 162 causes the imaging device 117 to start capturing an image of the medium (step S106).

[0081] Next, the control unit 161 waits until the trailing edge of the conveyed medium passes through the nip portion between the feed roller 112 and the separation roller 113 (step S107). For example, the control unit 161 determines that the trailing edge of the medium has passed through the nip portion between the feed roller 112 and the separation roller 113 when a first predetermined time has elapsed since the start of feeding of the medium. The first predetermined time is set to the time required for the leading edge of a medium of the maximum size supported by the medium feeding device 100 to move from the upstream end of the nip portion between the feed roller 112 and the separation roller 113 to the downstream end of the nip portion, plus a margin. Note that in the medium feeding device 100, a medium sensor similar to the second medium sensor 116 may be provided between the feed roller 112 and the first conveyance roller 114 in the medium conveyance direction A1, particularly near the feed roller 112. In this case, the control unit 161 may determine that the rear end of the medium has passed through the nip between the feed roller 112 and the separation roller 113 when the signal value of the medium signal output from the medium sensor changes from a value indicating the presence of the medium to a value indicating the absence of the medium.

[0082] In this way, the control unit 161 controls the first motor 130 to stop the feed roller 112 at least while the trailing edge of the medium passes through the nip between the feed roller 112 and the separation roller 113 .

[0083] FIG. 10C is a schematic diagram showing the state of the medium immediately after the trailing edge passes through the nip portion between the feeding roller 112 and the separation roller 113. As shown in FIG.

[0084] 10(C), when the trailing end of medium M1 passes through the nip portion between feed roller 112 and separation roller 113, the state is such that feeding of the medium following medium M1 may begin. By stopping feed roller 112 while the trailing end of the medium passes through the nip portion between feed roller 112 and separation roller 113, media other than medium M1 placed on mounting table 103 may be fed, thereby preventing double feeding of media.

[0085] Next, control unit 161 determines whether or not a medium remains on mounting table 103 based on the first medium signal received from first medium sensor 111 (step S108).

[0086] If media remain on the mounting table 103, the control unit 161 controls the first motor 130 to rotate the feed roller 112 again, thereby feeding and transporting the subsequent media (step S109).

[0087] Next, image acquisition unit 162 waits until the trailing edge of the preceding medium passes the imaging position (step S110). Control unit 161 periodically acquires a second medium signal from second medium sensor 116, and determines that the trailing edge of the preceding medium has passed the position of second medium sensor 116 when the signal value of the second medium signal changes from a value indicating the presence of a medium to a value indicating the absence of a medium. Control unit 161 determines that the trailing edge of the preceding medium has passed the imaging position when a second predetermined time has elapsed since the trailing edge of the preceding medium passed the position of second medium sensor 116. The second predetermined time is set to the time required for the medium to move from the position of second medium sensor 116 to the imaging position plus a margin.

[0088] Next, the image acquisition unit 162 stops imaging by the imaging device 117 and acquires an input image from the imaging device 117. The image acquisition unit 162 outputs the acquired input image by transmitting it to the information processing device via the interface device 142 (step S111). Next, the control unit 161 returns the process to step S104 and repeats the processes from step S104 onwards for the subsequent medium.

[0089] On the other hand, if there are no media remaining on the mounting table 103 in step S108, the image acquiring unit 162 waits until the rear end of the transported medium passes the imaging position, similar to the process in step S110 (step S112).

[0090] Next, the image acquisition unit 162 acquires an input image in the same manner as in step S111, and outputs the image by transmitting it to the information processing device via the interface device 142 (step S113).

[0091] Next, the control unit 161 waits until the trailing edge of the transported medium passes the first discharge roller 118 and the second discharge roller 119 (step S114). The control unit 161 determines that the trailing edge of the medium has passed the first discharge roller 118 and the second discharge roller 119 when a third predetermined time has elapsed since the trailing edge of the medium passed the position of the second medium sensor 116. The third predetermined time is set to a value obtained by adding a margin to the time required for the medium to move from the position of the second medium sensor 116 to the downstream end of the nip portion between the first discharge roller 118 and the second discharge roller 119.

[0092] Next, the control unit 161 controls the second motor 141 to stop the separation roller 113, the first conveying roller 114, the second conveying roller 115, the first discharge roller 118 and / or the second discharge roller 119 (step S115), and ends the series of steps.

[0093] The technical significance of stopping the feed roller 112 while applying a load against the rotation of the feed roller to the driving force transmission unit 131 by the application unit 136 will be described below.

[0094] FIG. 11(A) is a schematic diagram showing the relationship between the second gear and the third gear.

[0095] In step S103 or S109, when the control unit 161 controls the first motor 130 to rotate the feed roller 112, the driving force from the first motor 130 rotates the second gear 134b in the direction of arrow B4, as shown in FIG. 11A. As a result, the end C1 of the teeth of the second gear 134b on the rotational direction side abuts against the end C2 of the teeth of the third gear 134c on the opposite side of the rotational direction, and the third gear 134c and the shaft 135 are rotated in the direction of arrow B5 by the second gear 134b. As a result, the feed roller 112 rotates in the medium feed direction A4, as shown in FIG. 10A.

[0096] Then, in step S105, when the control unit 161 controls the first motor 130 to stop the feed roller 112, the second gear 134b stops. At this time, as shown in FIG. 10B, the feed roller 112 is rotated in the medium conveying direction A4 by the medium M1 conveyed by the first conveying roller 114 and the second conveying roller 115. However, due to the action of the one-way clutch 112a, the rotational force of the feed roller 112 is not transmitted to the shaft 135. At this time, a frictional force is generated in the one-way clutch 112a. However, as described above, the force applied to the third gear 134c by the application unit 136 is set to be greater than the frictional force generated in the one-way clutch 112a. Therefore, the shaft 135 and the third gear 134c remain stopped, and the end C1 of the second gear 134b on the rotational direction side continues to abut against the end C2 of the third gear 134c on the opposite side of the rotational direction.

[0097] Then, in step S107, when the trailing edge of the medium passes through the nip between the feed roller 112 and the separation roller 113, the feed roller 112 comes into contact with the separation roller 113, as shown in FIG. 10C. As a result, the feed roller 112 rotates along with the separation roller 113, which rotates in the direction A5 opposite the medium feed direction, and attempts to rotate in the direction opposite the medium feed direction A4. However, the second gear 134b is stopped by the driving force from the first motor 130. Furthermore, because the end C1 of the teeth of the second gear 134b on the rotational direction side abuts the end C2 of the teeth of the third gear 134c on the opposite side of the rotational direction, the shaft 135 and the third gear 134c cannot rotate in the direction opposite to the arrow B5. Therefore, the feed roller 112 does not rotate in the direction opposite the medium feed direction A4.

[0098] In this way, when the control unit 161 drives the first motor 130 to stop the feed roller 112, the feed roller 112 does not rotate in the opposite direction to the medium feed direction A4 due to the load applied by the applying unit 136. In other words, when the control unit 161 drives the first motor 130 to stop the feed roller 112, the applying unit 136 applies a load against the rotation of the feed roller 112 to the driving force transmission unit 131 so that the feed roller 112 does not rotate in the opposite direction to the medium feed direction A4.

[0099] FIG. 11(B) is a schematic diagram showing the relationship between the second gear and the third gear in another medium feeding device.

[0100] In FIG. 11B, gear G2 is attached to the shaft of the feed roller, and gear G1 is a gear that transmits driving force from the motor to gear G2. In this medium feeding device, gear G2 is not subjected to a load due to the rotation of the feed roller. Therefore, when the feed roller 112 is stopped, frictional force generated in one-way clutch 112a causes gear G2 to rotate in the direction of arrow B5. As a result, end D1 of the gear G1 teeth on the rotational direction side separates from end D2 of the gear G2 teeth on the opposite side of the rotational direction, creating a backlash (gap) between gears G1 and G2. Furthermore, when the trailing edge of the medium passes through the nip between the feed roller and separation roller and the feed roller and separation roller come into contact with each other, the separation roller rotates in the direction A5 opposite to the medium feeding direction due to elastic deformation of its surface (rubber). The feed roller rotates in the opposite direction to the medium feeding direction A4 due to the force from the separation roller rotating in the opposite direction A5 to the medium feeding direction.

[0101] FIG. 12 is a schematic diagram showing a state immediately before feeding of the subsequent medium in another medium feeding device.

[0102] When the feed roller R1 rotates in the opposite direction E1 of the medium feed direction due to the rotation of the separation roller R2, which rotates in the opposite direction E2 of the medium feed direction, the leading edge of medium M2, which is in contact with the feed roller R1, is pushed back toward the table. However, other media are stacked on top of medium M2, so medium M2 cannot return to the table. Therefore, as shown in Figure 12, the leading edge of medium M2, which is in contact with the feed roller R1, bends, causing a media jam or damage.

[0103] In the medium feeding device 100, when the feed roller 112 is driven by the medium conveyed by the first conveying roller 114 and the second conveying roller 115 or when it is about to be driven by the separation roller 113, the applying unit 136 applies a load against the rotation of the feed roller 112 to the driving force transmitting unit 131 so as to prevent backlash from occurring between the second gear 134b and the third gear 134c. By stopping the feed roller 112 while the applying unit 136 applies a load against the rotation of the feed roller to the driving force transmitting unit 131, the medium feeding device 100 can prevent the leading edge of the following medium from bending, which can cause the medium to jam or be damaged.

[0104] As described above in detail, in medium feeding device 100, control unit 161 controls first motor 130 to stop feed roller 112, and application unit 136 applies a load against the rotation of feed roller 112 to drive force transmission unit 131. This allows medium feeding device 100 to perform a pseudo-hold when stopping feed roller 112, thereby preventing the occurrence of media jams or damage to the media. Therefore, medium feeding device 100 is able to feed media appropriately.

[0105] Furthermore, medium feeding device 100 provides a general-purpose support member 137, a contact member 138, and a pressing member 139 to the bearing of shaft 135, which is the rotation axis of feed roller 112, thereby applying the load against the rotation of feed roller 112 to drive force transmission unit 131. This makes it possible for medium feeding device 100 to prevent the occurrence of media jams or damage to media while suppressing increases in device costs.

[0106] FIG. 13 is a diagram showing a schematic configuration of a processing circuit in a medium feeding device according to another embodiment.

[0107] The processing circuit 260 is used in place of the processing circuit 160, and executes media reading processing and the like in place of the processing circuit 160. The processing circuit 260 includes a control circuit 261, an image acquisition circuit 262, and the like. Note that these may each be configured as an independent integrated circuit, microprocessor, firmware, and the like.

[0108] The control circuit 261 is an example of a control unit, and has the same functions as the control unit 161. The control circuit 261 receives an operation signal from the display operation device 105 or the interface device 142, a first medium signal from the first medium sensor 111, and a second medium signal from the second medium sensor 116. The control circuit 261 controls the first motor 130 and the second motor 141 based on the received signals.

[0109] The image acquisition circuit 262 is an example of an image acquisition unit, and has the same function as the image acquisition unit 162. The image acquisition circuit 262 receives a second medium signal from the second medium sensor 116, acquires an input image from the imaging device 117 based on the received second medium signal, and outputs the input image to the interface device 142.

[0110] As described above in detail, the medium feeding device can feed the medium appropriately even when the processing circuit 260 is used.

[0111] Although preferred embodiments have been described above, the embodiments are not limited to these. For example, the applying unit 136 may be provided so as to apply the load for rotation of the feed roller 112 to the feed roller 112, rather than to the driving force transmitting unit 131. In this case, a contact member similar to the contact member 138 and / or a pressing member similar to the pressing member 139 is provided between the feed roller 112 and a frame (not shown) provided in the lower housing 101. The contact member comes into contact with the side surface of the feed roller 112 to apply a frictional force to the feed roller 112. The pressing member presses the contact member toward the feed roller 112.

[0112] The medium transport path of the medium feeding device may have a so-called U-turn path mechanism, which feeds and transports the media placed on the loading table from the top to the bottom and discharges them onto the discharge table. In this case, the separation roller is disposed below the feeding roller and faces the feeding roller.

[0113] The medium feeding device may also have an image forming device instead of or in addition to the imaging device 117. The image forming device is an inkjet or laser type printer, etc., and is placed at a position corresponding to the position where the imaging device 117 is placed, and forms an image (prints predetermined information) on the medium being transported. [Explanation of symbols]

[0114] 100 medium feeding device, 112 feeding roller, 113 separation roller, 114 first conveying roller, 115 second conveying roller, 130 first motor, 134c third gear, 136 application unit, 161 control unit

Claims

1. a feeding roller for feeding the medium; a drive source that generates a drive force for driving the feed roller; a control unit that controls the drive source and is capable of controlling the drive source to stop the feed roller; an applying unit that applies a load to the rotation of the feeding roller; A medium feeding device comprising:

2. a conveying roller disposed downstream of the feeding roller in a medium conveying direction; The medium feeding device according to claim 1 , wherein the control unit controls the drive source to stop the feeding roller after the leading edge of the medium has passed the transport roller.

3. a separation roller disposed opposite the feeding roller and rotatable in a direction opposite to the medium feeding direction; The medium feeding device according to claim 1 , wherein the control unit controls the drive source to stop the feeding roller at least while the trailing edge of the medium passes through a nip portion between the feeding roller and the separation roller.

4. a gear for transmitting the driving force to the feeding roller; The medium feeding device according to claim 1 , wherein the applying section applies the load by pressing the gear in a rotation axis direction.

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

6. The medium feeding device of claim 5, wherein the control unit controls the drive source to stop the feeding roller by short-circuiting terminals on both sides of the DC motor or by passing a predetermined current through the DC motor.

7. A medium feeding device including a feeding roller that feeds a medium, a drive source that generates a driving force for driving the feeding roller, a control unit that controls the drive source, and an applying unit that applies a load to the rotation of the feeding roller, When the control unit drives the drive source to stop the feed roller, the feed roller does not rotate in the direction opposite to the medium feed direction due to the load applied by the application unit. A medium feeding device characterized by:

8. A feed roller feeds the medium. a drive source generates a drive force for driving the feed roller; a load applying unit applying a load to the rotation of the feed roller; controlling the driving source so as to be able to stop the feeding roller; A medium feeding method comprising:

9. A control program for a medium feeding device having a feeding roller that feeds a medium, a drive source that generates a driving force for driving the feeding roller, and an applying unit that applies a load to the rotation of the feeding roller, the program comprising: controlling the driving source so as to be able to stop the feeding roller; a control program for causing the medium feeding device to execute the above steps;

Images