MEDIUM CONVEYING DEVICE, MEDIUM FEEDING METHOD, AND CONTROL PROGRAM

Abstract

Provided is a medium conveyance device that is capable of more suitably restoring a medium when overlapping delivery of the medium has occurred. The present invention has a placement platform, a feeding roller for feeding a medium placed on the placement platform, a separation roller disposed facing the feeding roller, a first motor for driving the feeding roller, a second motor for driving the separation roller, an assessment unit that assesses whether or not overlapping delivery of the medium has occurred, and a control unit that controls the first and second motors so as to return the medium to the placement platform if the assessment unit has assessed that overlapping delivery of the medium has occurred, the control unit controlling the first and second motors such that, when the medium is returned to the placement platform, the feeding roller is rotated after the separation roller is rotated.

Description

[Technical field]

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

[0002] In a media transport device such as a scanner that sequentially feeds and captures a plurality of media while separating them, if a duplicate feed of media occurs, the user must remove the media from the housing and reset them on the mounting table. In order to improve user convenience, it is desirable for the media transport device to automatically return the media to the mounting table when a duplicate feed of media occurs.

[0003] A paper feeder is disclosed that includes a conveying roller, a shaft connected to the conveying roller via a one-way clutch structure and rotated in a first direction and a second direction by the driving force of a first drive motor, and a separation roller to which the driving force of a second drive motor is transmitted (see Patent Document 1). This paper feeder has a first mode in which the shaft rotates in the first direction to rotate the conveying roller in the first direction, and a second mode in which the shaft rotates in the second direction to release the restriction on the rotation of the conveying roller in the second direction. In the second mode, the paper feeder starts driving the first drive motor to rotate the shaft in the second direction, and then drives the second drive motor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5559843 Summary of the Invention

[0005] In a medium conveying device, it is desirable to more appropriately recover the media when a duplicated medium feed occurs.

[0006] A medium transport device, a medium feeding method, and a control program according to the embodiments aim to more appropriately recover a medium when a duplicated medium feed occurs.

[0007] According to one aspect of the embodiment, a medium transport device includes a mounting table, a feed roller for feeding a medium mounted on the mounting table, a separation roller disposed opposite the feed roller, and a roller for driving the feed roller. Generates the first driving force a first motor for driving the separation roller; Generates a second driving force A second motor; a first transmission section that transmits a first driving force to the feeding roller; and a second transmission section that transmits a second driving force to the separation roller. The device includes a determination unit that determines whether or not a duplicated feed of media has occurred, and a control unit that controls the first motor and the second motor to return the media to the placement table when the determination unit determines that a duplicated feed of media has occurred, and the control unit controls the first motor and the second motor to rotate the separation roller and then the feed roller when returning the media to the placement table. At least one of the first transmission part and the second transmission part has a backlash component. .

[0008] A medium feeding method according to one aspect of an embodiment includes a step of feeding a medium placed on a placement table by a feeding roller, determining whether or not a double feed of the medium has occurred, and, if it is determined that a double feed of the medium has occurred, driving the feeding roller to stop the medium once and then return it to the placement table. Generates the first driving force A first motor and a separation roller disposed opposite the feed roller are provided. Generates a second driving force The second motor is controlled to rotate the first motor and the second motor so that, when returning the medium to the placement table, the separation roller is rotated first and then the feed roller is rotated. and at least one of a first transmission section that transmits the first driving force to the feed roller and a second transmission section that transmits the second driving force to the separation roller has a backlash component. .

[0009] According to one aspect of the embodiment, a control program includes a mounting table, a feed roller for feeding a medium placed on the mounting table, a separation roller disposed opposite the feed roller, and a control program for driving the feed roller. Generates the first driving force a first motor for driving the separation roller; Generates a second driving force A second motor; a first transmission section that transmits a first driving force to the feeding roller; and a second transmission section that transmits a second driving force to the separation roller.a control program for a medium conveying device having the program, the program causing the medium conveying device to determine whether or not a duplicated medium feed has occurred, and, if it is determined that a duplicated medium feed has occurred, to control a first motor and a second motor so as to stop the medium once and then return it to a placement table, and to control the first motor and the second motor so as to rotate a separation roller and then a feed roller when returning the medium to the placement table. At least one of the first transmission part and the second transmission part has a backlash component. .

[0010] According to the present embodiment, the medium transport device, the medium feeding method, and the control program are capable of more appropriately recovering the medium when a duplicated medium feed occurs.

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

[0012] [Figure 1] 1 is a perspective view showing a medium conveying device 100 according to an embodiment. [Diagram 2] 2 is a diagram for explaining a transport path inside the medium transport device 100. FIG. [Diagram 3] 13 is a schematic diagram for explaining a restriction guide 112 and the like. FIG. [Figure 4] 13 is a schematic diagram for explaining the operation of the restriction guide 112 and the like. FIG. [Diagram 5] 13 is a schematic diagram for explaining a storage section 134. FIG. [Figure 6] 1 is a block diagram showing a schematic configuration of a medium conveying device 100. FIG. [Figure 7] FIG. 2 is a diagram showing a schematic configuration of a storage device 140 and a processing circuit 150. [Figure 8] 10 is a flowchart illustrating an example of the operation of a medium reading process. [Figure 9] 10 is a flowchart illustrating an example of the operation of a medium reading process. [Figure 10] 6 is a graph for explaining a change in speed of a feed roller 115 and the like. [Figure 11] 10 is a flowchart illustrating an example of the operation of a multifeed detection process. [Figure 12] 11 is a schematic diagram for explaining the operation of returning the medium to the mounting table 103. FIG. [Figure 13] 13 is a diagram for explaining a transport path inside another medium transport device 200. FIG. [Figure 14] FIG. 13 is a diagram showing a schematic configuration of another processing circuit 350. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, a medium conveying device, a medium feeding method, and a control program according to one aspect of the present disclosure will be described with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to the embodiments, but extends to the inventions described in the claims and their equivalents.

[0014] 1 is a perspective view showing a medium conveying device 100 configured as an image scanner. The medium conveying device 100 conveys a medium, which is an original document, and captures an image of the medium. The medium is paper, thin paper, thick paper, a card, a booklet, a passport, or the like. The medium conveying device 100 may be a facsimile, a copier, a multifunction printer (MFP, Multifunction Peripheral), or the like. Note that the medium being conveyed may not be an original document, but may be a print target, or the like, and the medium conveying device 100 may be a printer, or the like.

[0015] The medium transport device 100 includes a lower housing 101, an upper housing 102, a loading stand 103, an ejection stand 104, an operation device 105, and a display device 106. In Fig. 1, an arrow A1 indicates the medium transport direction, an arrow A2 indicates the width direction perpendicular to the medium transport direction, and an arrow A3 indicates the height direction perpendicular to the medium transport path. In the following, 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.

[0016] The upper housing 102 is disposed in a position that covers the top surface of the medium conveying device 100, and engages with the lower housing 101 by a hinge so that it can be opened and closed when the medium is jammed or when the inside of the medium conveying device 100 is cleaned.

[0017] The placement stage 103 engages with the lower housing 101 and places thereon the media to be fed and transported. The ejection stage 104 engages with the upper housing 102 and places thereon the ejected media. Note that the ejection stage 104 may also engage with the lower housing 101.

[0018] The operation device 105 has an input device such as a button and an interface circuit for acquiring a signal from the input device, accepts an input operation by a user, and outputs an operation signal according to the input operation by the user. The display device 106 has a display including a liquid crystal, an organic EL (Electro-Luminescence), or the like, and an interface circuit for outputting image data to the display, and displays the image data on the display.

[0019] FIG. 2 is a diagram for explaining a transport path inside the medium transport device 100. As shown in FIG.

[0020] The transport path inside the media transport device 100 includes a first media sensor 111, a regulating guide 112, a cam member 113, a flap 114, a feed roller 115, a separation roller 116, a second media sensor 117, an ultrasonic sensor 118, a transport roller 119, a first opposing roller 120, a third media sensor 121, an imaging device 122, a discharge roller 123, and a second opposing roller 124, etc.

[0021] The number of each of the feed roller 115, separation roller 116, transport roller 119, first opposed roller 120, discharge roller 123, and / or second opposed roller 124 is not limited to one, and may be more than one. In this case, the multiple feed rollers 115, separation roller 116, transport roller 119, first opposed roller 120, discharge roller 123, and / or second opposed roller 124 are arranged at intervals in the width direction A2 perpendicular to the medium transport direction.

[0022] 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.

[0023] The first medium sensor 111 is disposed upstream of the feed roller 115 and the separation roller 116. 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 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 a light detection sensor, may be used as the first medium sensor 111.

[0024] The feed roller 115 is provided in the lower housing 101, and separates and feeds the media placed on the mounting table 103 from the bottom. The separation roller 116 is a so-called brake roller or retard roller, and is provided in the upper housing 102, and disposed opposite the feed roller 115. The separation roller 116 is provided so as to be rotatable or stoppable in the direction opposite to the medium feeding direction. Note that the feed roller 115 may be provided in the upper housing 102 and the separation roller 116 in the lower housing 101, and the feed roller 115 may feed the media placed on the mounting table 103 from the top.

[0025] The second medium sensor 117 is disposed downstream of the feed roller 115 and upstream of the transport roller 119, and detects a medium transported to that position. The second medium sensor 117 includes a light emitter and a light receiver provided on one side of the medium transport path, and a light guide tube provided at a position facing the light emitter and the light receiver across the medium transport path. The light emitter is an LED (Light Emitting Diode) or the like, and emits light toward the medium transport path. On the other hand, the light receiver is a photodiode or the like, and receives the light emitted by the light emitter and guided by the light guide tube. When a medium is present at a position facing the second medium sensor 117, the light emitted from the light emitter is blocked by the medium, so the light receiver does not detect the light emitted from the light emitter. The second medium sensor 117 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 117, based on the intensity of the light received by the light receiver.

[0026] A reflective member such as a mirror may be used instead of the light guide tube. The light emitter and the light receiver may be provided facing each other across the medium transport path. The second medium sensor 117 may detect the presence of the 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.

[0027] The ultrasonic sensor 118 is disposed downstream of the feed roller 115, particularly downstream of the second medium sensor 117 and upstream of the conveying roller 119. The ultrasonic sensor 118 includes an ultrasonic transmitter 118a and an ultrasonic receiver 118b. The ultrasonic transmitter 118a and the ultrasonic receiver 118b are disposed near the conveying path of the medium, facing each other across the conveying path. The ultrasonic transmitter 118a emits ultrasonic waves. Meanwhile, the ultrasonic receiver 118b receives ultrasonic waves emitted by the ultrasonic transmitter 118a and transmitted through the medium, and generates and outputs an ultrasonic signal, which is an electrical signal corresponding to the received ultrasonic waves. When multiple media are conveyed in an overlapping manner, the ultrasonic waves transmitted through the media are attenuated by the air layer between the overlapping media. Therefore, the medium conveying device 100 can detect the double feeding of media based on the ultrasonic signal.

[0028] The transport roller 119 and the first opposed roller 120 are disposed opposite each other downstream of the feed roller 115 and the separation roller 116 in the medium transport direction A1. The transport roller 119 is provided in the upper housing 102, and transports the medium fed by the feed roller 115 and the separation roller 116 to the imaging device 122. Note that the transport roller 119 may be provided in the lower housing 101, and the first opposed roller 120 may be provided in the upper housing 102.

[0029] The third medium sensor 121 is disposed downstream of the transport rollers 119 and upstream of the imaging device 122, and detects a medium transported to that position. The third medium sensor 121 includes a light emitter and a light receiver provided on one side of the medium transport path, and a light guide tube provided at a position facing the light emitter and the light receiver across the medium transport path. The light emitter is an LED or the like, and emits light toward the medium transport path. Meanwhile, the light receiver is a photodiode or the like, and receives the light emitted by the light emitter and guided by the light guide tube. The third medium sensor 121 generates and outputs a third medium signal, the signal value of which changes depending on whether a medium is present or not at the position of the third medium sensor 121, based on the intensity of the light received by the light receiver.

[0030] A reflective member such as a mirror may be used instead of the light guide tube. The light emitter and the light receiver may be provided facing each other across the medium transport path. The third medium sensor 121 may detect the presence of the medium by a contact detection sensor that passes a predetermined current when the medium is in contact or when the medium is not in contact.

[0031] The imaging device 122 is an example of an imaging section, and is disposed downstream of the transport roller 119 and the first opposed roller 120 in the medium transport direction A1, and captures an image of the medium transported by the transport roller 119 and the first opposed roller 120. The imaging device 122 includes a first imaging device 122a and a second imaging device 122b disposed opposite each other across the medium transport path.

[0032] The first imaging device 122a has a line sensor using a CIS (Contact Image Sensor) of a life-size optical system type having imaging elements using CMOS (Complementary Metal Oxide Semiconductor) linearly arranged in the main scanning direction. The first imaging device 122a also has a lens that forms an image on the imaging elements, and an A / D converter that amplifies and analog-to-digital (A / D) converts the electrical signal output from the imaging elements. The first imaging device 122a captures an image of the surface of the medium being conveyed, generates an input image, and outputs it, according to control from a processing circuit described later.

[0033] Similarly, the second imaging device 122b has a line sensor using a CIS of a life-size optical system type having CMOS imaging elements arranged in a line in the main scanning direction. The second imaging device 122b 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 122b captures the back side of the medium being conveyed under the control of a processing circuit described later, generates an input image, and outputs it.

[0034] The medium conveying device 100 may have only one of the first imaging device 122a and the second imaging device 122b arranged, and may read only one side of the medium. Also, instead of a CIS line sensor of an equal magnification optical system type having a CMOS imaging element, a CIS line sensor of an equal magnification optical system type having a CCD (Charge Coupled Device) imaging element may be used. Also, a reduction optical system type line sensor having a CMOS or CCD imaging element may be used.

[0035] The discharge roller 123 and the second opposed roller 124 are disposed opposite each other in the medium conveying direction A1 from the imaging device 122, i.e., downstream from the conveying roller 119 and the first opposed roller 120. The discharge roller 123 is provided in the upper housing 102, and conveys the medium conveyed by the conveying roller 119 and the first opposed roller 120 further downstream and discharges it onto the discharge tray 104. Note that the discharge roller 123 may be provided in the lower housing 101, and the second opposed roller 124 may be provided in the upper housing 102.

[0036] The medium placed on the placement table 103 is conveyed between the lower guide 101a and the upper guide 102a in the medium conveying direction A1 by the rotation of the feed roller 115 in the direction of the arrow A4, i.e., the medium feeding direction. The medium conveying device 100 has a separation mode in which the medium is separated while being fed, and a non-separation mode in which the medium is fed without being separated, as the feeding mode. The feeding mode is set by the user using the operation device 105 or an information processing device that is communicatively connected to the medium conveying device 100. When the feeding mode is set to the separation mode, the separation roller 116 rotates or stops in the direction of the arrow A5, i.e., the opposite direction to the medium feeding direction. When multiple media are placed on the placement table 103, only the media in contact with the feed roller 115 among the media placed on the placement table 103 is separated by the action of the feed roller 115 and the separation roller 116. This limits the conveyance of media other than the separated media (prevention of double feeding). On the other hand, when the feeding mode is set to the non-separation mode, the separation roller 116 rotates in the direction opposite to the arrow A5, that is, in the medium feeding direction.

[0037] The medium is fed between the transport roller 119 and the first opposing roller 120 while being guided by the lower guide 101a and the upper guide 102a. The medium is fed between the first imaging device 122a and the second imaging device 122b as the transport roller 119 and the first opposing roller 120 rotate in the directions of the arrows A6 and A7, respectively. The medium read by the imaging device 122 is discharged onto the discharge tray 104 as the discharge roller 123 and the second opposing roller 124 rotate in the directions of the arrows A8 and A9, respectively.

[0038] As shown in FIG. 2, the medium conveying device 100 has a first motor 131, a second motor 132, and a third motor 133 as drive sources for the rollers.

[0039] The first motor 131 is provided in the lower housing 101, and is connected to the feed roller 115 via a first transmission mechanism 131a to drive the feed roller 115. The first motor 131 generates a driving force for driving the feed roller 115 in response to a control signal from a processing circuit. The first transmission mechanism 131a includes one or more pulleys, belts, gears, etc. provided between the first motor 131 and a shaft 115a which is a rotation axis of the feed roller 115, and transmits the driving force generated by the first motor 131 to the feed roller 115. As a result, the first motor 131 rotates the feed roller 115 to feed the medium. The first motor 131 may be disposed in the upper housing 102.

[0040] The second motor 132 is provided in the upper housing 102 separately from the first motor 131, and is connected to the separation roller 116 via the second transmission mechanism 132a to drive the separation roller 116. The second motor 132 generates a driving force for driving the separation roller 116 in response to a control signal from the processing circuit. The second transmission mechanism 132a includes one or more pulleys, belts, gears, etc. provided between the second motor 132 and the shaft 116a which is the rotation axis of the separation roller 116. The second transmission mechanism 132a transmits the driving force generated by the second motor 132 to the separation roller 116. As a result, the second motor 132 rotates the separation roller 116 to cause the separation roller 116 to separate, feed, and transport the medium. The second motor 132 may be disposed in the lower housing 101.

[0041] The third motor 133 is provided in the upper housing 102 separately from the first motor 131 and the second motor 132. The third motor 133 is connected to the conveying roller 119, the discharge roller 123, and the cam member 113 via a third transmission mechanism 133a, and drives the conveying roller 119, the discharge roller 123, and the cam member 113. The third motor 133 generates a driving force for driving the conveying roller 119, the discharge roller 123, and the cam member 113 in response to a control signal from the processing circuit. The third transmission mechanism 133a includes one or more pulleys, belts, gears, etc. provided between the third motor 133 and a shaft 119a which is a rotation shaft of the conveying roller 119, a shaft 123a which is a rotation shaft of the discharge roller 123, and a rotation shaft 113a of the cam member 113. The third transmission mechanism 133a transmits the driving force generated by the third motor 133 to the transport roller 119, the discharge roller 123, and the cam member 113. As a result, the third motor 133 rotates the transport roller 119 and the discharge roller 123, causing the transport roller 119 and the discharge roller 123 to transport and discharge the medium. That is, the transport roller 119 and the discharge roller 123 are provided so as to be driven by the third motor 133. In addition, the third motor 133 rotates the cam member 113 to move the regulating guide 112 that abuts against the cam member 113. The third motor 133 may be disposed in the lower housing 101.

[0042] In this way, in the medium conveying device 100, a common motor is used as the motor for driving the conveying roller 119 and the discharge roller 123, and as the motor for moving the regulating guide 112. This makes it possible for the medium conveying device 100 to have a smaller number of motors, thereby reducing the cost and weight of the device.

[0043] The first opposing roller 120 is a driven roller that rotates following the conveying roller 119, and the second opposing roller 124 is a driven roller that rotates following the discharge roller 123. The first opposing roller 120 and / or the second opposing roller 124 may be provided so as to be driven by a driving force from a third motor 133. In this case, one or more gears are further provided between the shaft 119a of the conveying roller 119 and the shaft 120a which is the rotation shaft of the first opposing roller 120 and / or between the shaft 123a of the discharge roller 123 and the shaft 124a which is the rotation shaft of the second opposing roller 124. The third transmission mechanism 133a further transmits the driving force generated by the third motor 133 to the first opposing roller 120 and / or the second opposing roller 124.

[0044] Fig. 3 is a schematic diagram for explaining the regulating guide 112, the cam member 113, and the flap 114. Fig. 3 is a schematic diagram of the regulating guide 112, the cam member 113, and the flap 114 as viewed from the side before the medium is fed.

[0045] As shown in Fig. 3, the regulating guide 112 is a guide for setting the medium (group) M1 placed on the placement table 103. The regulating guide 112 is disposed at a position facing the feed roller 115 and the separation roller 116 in the medium transport direction A1. The regulating guide 112 is rotatably (swingably) supported by the lower housing 101, and supports the bottom surface of the medium M1 placed on the placement table 103 when feeding of the medium M1 is not being performed. Hereinafter, the position where the regulating guide 112 supports the bottom surface of the medium M1 placed on the placement table 103 as shown in Fig. 3 may be referred to as a set position.

[0046] The cam member 113 is a moving member for moving the regulating guide 112. The cam member 113 is disposed downstream of the regulating guide 112 in the medium transport direction A1. The cam member 113 is provided so as to be rotatable (swingable) by the third motor 133. The cam member 113 is supported by the lower housing 101 so as to be rotatable according to a driving force from the third motor 133, and when the feeding of the medium is not being performed, the cam member 113 comes into contact with the downstream end of the regulating guide 112 to hold the regulating guide 112 in the set position.

[0047] The flap 114 is a stopper for preventing the medium M1 from entering the nip portion between the feed roller 115 and the separation roller 116 before the medium is fed. The flap 114 is disposed at a position facing the regulating guide 112 in the medium transport direction A1. The flap 114 is provided to be swingable on the upper housing 102, and engages with the regulating guide 112 disposed at the set position when feeding of the medium M1 is not being performed, thereby preventing the medium M1 from entering the nip portion between the feed roller 115 and the separation roller 116.

[0048] That is, at the set position, the regulating guide 112 regulates the medium M1 from contacting the feed roller 115 and the separation roller 116. The set position is an example of a first position.

[0049] Fig. 4 is a schematic diagram for explaining the operations of the regulating guide 112, the cam member 113, and the flap 114. Fig. 4 is a schematic diagram of the regulating guide 112, the cam member 113, and the flap 114 as viewed from the side during medium feeding.

[0050] As shown in Fig. 4, when feeding of the medium M1 is performed, the cam member 113 swings (rotates) downward (in the direction of arrow A11) in accordance with the driving force from the third motor 133 and moves away from the downstream end of the regulating guide 112. When the downstream end of the regulating guide 112 moves away from the cam member 113 and is no longer held by the cam member 113, the regulating guide 112 swings downward (in the direction of arrow A12) from the medium transport surface and moves away from the bottom surface of the medium M1 placed on the placement table 103. Hereinafter, the position where the regulating guide 112 moves away from the bottom surface of the medium M1 placed on the placement table 103 as shown in Fig. 4 may be referred to as the release position. When the regulating guide 112 is placed in the release position, the engagement between the flap 114 and the regulating guide 112 is released. As a result, the flap 114 is pushed by the leading edge of the medium M1 placed on the placement table 103 and swings downstream (in the direction of arrow A13), allowing the medium M1 to enter the nip portion between the feed roller 115 and the separation roller 116. In this manner, the flap 114 allows the medium M1 to enter the nip portion between the feed roller 115 and the separation roller 116 when the regulating guide 112 is placed in the release position.

[0051] That is, in the release position, the regulating guide 112 does not regulate the medium M1 from contacting the feed roller 115 and the separation roller 116. The release position is an example of the second position. The regulating guide 112 is provided so as to be movable between the set position and the release position. The regulating guide 112 is provided so as to move when the cam member 113 rotates.

[0052] 3 and 4, the feed roller 115 is provided with an outer peripheral surface 115b, a one-way clutch 115c, and the like. The one-way clutch 115c is disposed on a shaft 115a which is a rotation axis of the feed roller 115. The one-way clutch 115c prevents the feed roller 115 (its outer peripheral surface 115b) from rotating in the opposite direction to the medium feeding direction A4 relative to the shaft 115a. This prevents the feed roller 115 from being dragged by the separation roller 116 which rotates in the opposite direction A5 to the medium feeding direction and rotating in the opposite direction to the medium feeding direction A4.

[0053] The transport roller 119 transports the medium at a transport speed faster than the feeding speed of the feed roller 115. Therefore, when the medium reaches the position of the transport roller 119, the medium is pulled by the transport roller 119 while being sandwiched between the feed roller 115 and the separation roller 116. At this time, the outer peripheral surface 115b of the feed roller 115 rotates along with the medium being sandwiched due to the action of the one-way clutch 115c, and does not impede the transport of the medium. The transport roller 119 may transport the medium at the same transport speed as the feeding speed of the feed roller 115.

[0054] The separation roller 116 is provided with an outer peripheral surface 116b and a torque limiter 116c. The torque limiter 116c is disposed on the shaft 116a, which is the rotation axis of the separation roller 116. The torque limiter 116c defines the maximum torque applied to the separation roller 116. The limit value of the torque limiter 116c is set to a value such that the rotation force via the torque limiter 116c is cut off when there is one medium, and the rotation force via the torque limiter 116c is transmitted when there are multiple media. As a result, when only one medium is transported, the separation roller 116 does not rotate according to the driving force from the second motor 132, but is driven by the feed roller 115. On the other hand, when multiple media are transported, the separation roller 116 rotates in the direction A3 opposite to the medium feeding direction, and separates the medium in contact with the feed roller 115 from the other media to prevent double feeding. At this time, the outer peripheral surface 116b of the separation roller 116 may apply a force to the medium in the direction A5 opposite to the medium feeding direction while being stopped and not rotating in the direction A5 opposite to the medium feeding direction.

[0055] FIG. 5 is a schematic diagram for explaining the storage section 134. As shown in FIG.

[0056] As shown in FIG. 5, the lower housing 101 is provided with a storage section 134. The storage section 134 stores attachments such as paper powder or dirt attached to the medium being transported, or attachments attached to the feed roller 115 or the separation roller 116 from the medium being transported. The lower guide 101a, which is the medium guide surface of the lower housing 101, has an opening 101b for arranging the feed roller 115. The storage section 134 is disposed below the feed roller 115 so as to face the opening 101b, and stores the medium being transported, the attachments that have fallen from the feed roller 115 or the separation roller 116, and entered through the gap between the feed roller 115 and the opening 101b. The storage section 134 is provided detachably from the lower housing 101, i.e., from the medium transport device 100. The container 134 allows the medium conveying device 100 to appropriately collect paper dust or dirt, and prevents the paper dust or dirt from accumulating in the medium conveying path.

[0057] FIG. 6 is a block diagram showing a schematic configuration of the medium conveying device 100. As shown in FIG.

[0058] In addition to the components described above, the medium conveying device 100 further includes an interface device 135, a storage device 140, a processing circuit 150, and the like.

[0059] The interface device 135 has an interface circuit conforming to a serial bus such as USB, and is electrically connected to an information processing device (not shown, for example, a personal computer, a mobile information terminal, etc.) to transmit and receive input images and various information. Also, instead of the interface device 135, a communication unit having an antenna for transmitting and receiving wireless signals and a wireless communication interface device for transmitting and receiving signals through 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 through a wired communication line in accordance with a communication protocol such as a wired LAN.

[0060] The storage device 140 includes a memory device such as a random access memory (RAM) or a read only memory (ROM), a fixed disk device such as a hard disk, or a portable storage device such as a flexible disk or an optical disk. The storage device 140 also stores computer programs, databases, tables, and the like used for various processes of the medium conveying device 100. The computer programs may be installed in the storage device 140 from a computer-readable portable recording medium using a known setup program or the like. The portable recording medium is, for example, a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), or the like.

[0061] The processing circuit 150 operates based on a program previously stored in the storage device 140. The processing circuit is, for example, a CPU (Central Processing Unit). The processing circuit 150 may be, for example, a DSP (digital signal processor), an LSI (large scale integration), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array).

[0062] The processing circuit 150 is connected to the operation device 105, the display device 106, the first medium sensor 111, the second medium sensor 117, the ultrasonic sensor 118, the third medium sensor 121, the imaging device 122, the first motor 131, the second motor 132, the third motor 133, the interface device 135, the storage device 140, and the like, and controls each of these components. The processing circuit 150 performs drive control of each motor and imaging control of the imaging device 122, etc., based on each medium signal received from each media sensor. The processing circuit 150 acquires an input image from the imaging device 122 and transmits it to the information processing device via the interface device 135. The processing circuit 150 also determines whether or not a double feed of media has occurred based on the ultrasonic signal received from the ultrasonic sensor 118, and if a double feed of media has occurred, controls each motor to return the media to the placement table 103.

[0063] FIG. 7 is a diagram showing a schematic configuration of the storage device 140 and the processing circuit 150. As shown in FIG.

[0064] 7, the storage device 140 stores a control program 141, a determination program 142, and the like. Each of these programs is a functional module implemented by software that runs on a processor. The processing circuit 150 reads each program stored in the storage device 140 and operates according to the read program. In this way, the processing circuit 150 functions as a control unit 151 and a determination unit 152.

[0065] 8 and 9 are flowcharts showing an example of the operation of the medium reading process of the medium conveying device 100. In FIG.

[0066] An example of the operation of the medium reading process of the medium conveying device 100 will be described below with reference to the flowcharts shown in Figures 8 and 9. Note that the flow of the operation described below is executed mainly by the processing circuit 150 in cooperation with each element of the medium conveying device 100 based on a program stored in advance in the storage device 140.

[0067] First, the control unit 151 waits until a user inputs an instruction to read a medium using the operation device 105 or an information processing device, and an operation signal instructing the user to read a medium is received from the operation device 105 or the interface device 135 (step S101).

[0068] Next, control unit 151 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 151 ends the series of steps.

[0069] On the other hand, when a medium is placed on the placement table 103, the control unit 151 first drives the third motor 133 (step S103). By driving the third motor 133, the control unit 151 rotates the cam member 113 in the direction of the arrow A11 in Fig. 3, and moves the regulating guide 112 in the direction of the arrow A12 in Fig. 3, that is, from the set position to the release position. In addition, the control unit 151 drives the third motor 133 to rotate the conveying roller 119, the first opposing roller 120, the discharge roller 123, and / or the second opposing roller 124 in the directions of the arrows A6, A7, A8, and / or A9 in Fig. 2, respectively.

[0070] Next, the control unit 151 drives the second motor 132 to rotate the separation roller 116 in the direction opposite to the medium feeding direction (in the direction of the arrow A5 in FIG. 2) (step S104).

[0071] Next, the control unit 151 drives the first motor 131 to rotate the feed roller 115 in the medium feed direction (the direction of the arrow A4 in FIG. 2) to feed the medium (step S105).

[0072] FIG. 10 is a graph for explaining the speed changes of the feed roller 115, the separation roller 116, and the transport roller 119. In FIG.

[0073] 10, graph G11 shows the speed change of feed roller 115, graph G12 shows the speed change of separation roller 116, and graph G13 shows the speed change of conveying roller 119. Since the speeds of first opposing roller 120, discharge roller 123, and second opposing roller 124 change in the same manner as the speed of conveying roller 119, the following will representatively explain the speed change of conveying roller 119. The horizontal axis of each of graphs G11 to G13 indicates time, and the vertical axis indicates speed.

[0074] Meanwhile, graph G14 shows the change in the signal value of second medium sensor 117, and graph G15 shows the change in the signal value of third medium sensor 121. The horizontal axis of each of graphs G14 and G15 indicates time, and the vertical axis indicates the signal value. In this embodiment, when no medium is present at each sensor, the signal value of the corresponding signal is L, and when a medium is present at each sensor, the signal value of the corresponding signal is H.

[0075] 10, time T1 indicates the start of medium feeding. As described above, the control unit 151 starts driving the third motor 133, the second motor 132, and the first motor 131 in that order, so that the conveying roller 119, the separation roller 116, and the feed roller 115 start rotating sequentially at times T1, T2, and T3. The speed (surface movement speed) V2 of the separation roller 116 is set to a speed lower than the speed (surface movement speed) V1 of the feed roller 115. Also, the speed (surface movement speed) V3 of the conveying roller 119 is set to a speed higher than the speed (surface movement speed) V1 of the feed roller 115.

[0076] Further, the control unit 151 starts driving the third motor 133, the second motor 132, and the first motor 131 in that order. Therefore, when the regulating guide 112 moves from the set position and the regulation of the medium by the flap 114 is released, that is, when the leading edge of the medium placed on the placement table 103 contacts the separation roller 116 and the feed roller 115, the feed roller 115 and the separation roller 116 are stopped. Then, before the feed roller 115 starts to rotate, the separation roller 116 starts to rotate. Therefore, as shown in FIG. 4, the medium group M1 placed on the placement table 103 contacts the separation roller 116 before entering the nip portion between the feed roller 115 and the separation roller 116. The leading edge of the medium group M1 is separated by the separation roller 116, which rotates in the opposite direction to the medium feeding direction, so that the upper medium is located upstream. This prevents a plurality of media from collectively entering the nip between the feed roller 115 and the separation roller 116 when the feed roller 115 starts to rotate, thereby preventing the occurrence of multiple media feeding.

[0077] In addition, by starting to rotate the separation roller 116 before the feed roller 115 starts to rotate, the separation roller 116 is prevented from being driven by the feed roller 115 before starting to rotate, and the separation roller 116 can separate the medium well.

[0078] The control unit 151 may execute the process of step S104 before the process of step S103, and operate the second motor 132 and then the third motor 133 when starting to feed the medium. In that case, when the regulating guide 112 moves from the set position and the leading edge of the medium contacts the separation roller 116 and the feed roller 115, the separation roller 116 rotates and the feed roller 115 is stopped. Therefore, even in that case, the medium conveying device 100 controls the first motor 131, the second motor 132, and the third motor 133 so that the separation roller 116 in the rotating state contacts the medium and then the feed roller 115 rotates. The leading edge of the medium group M1 is separated by the separation roller 116, which rotates in the opposite direction to the medium feeding direction, so that the upper medium is positioned upstream. This prevents a plurality of media from collectively entering the nip portion between the feed roller 115 and the separation roller 116 when the feed roller 115 starts to rotate, thereby preventing the occurrence of double feeding of media.

[0079] In addition, by starting to rotate the separation roller 116 before the feed roller 115 starts to rotate, the separation roller 116 is prevented from being driven by the feed roller 115 before starting to rotate, and the separation roller 116 can separate the medium well.

[0080] In this way, the control unit 151 controls the first motor 131, the second motor 132, and the third motor 133 so that, at the start of feeding the medium, the separation roller 116 in a rotating state comes into contact with the medium before the feeding roller 115 rotates. In particular, at the start of feeding the medium, the control unit 151 operates the second motor 132 and the third motor 133 before operating the first motor 131. This allows the control unit 151 to prevent the occurrence of multiple feeding of media at the start of feeding the medium.

[0081] As described above, the regulating guide 112 is provided so as to move as the cam member 113 rotates, and the regulating guide 112 and the flap 114 engage with each other to regulate the contact of the medium with the feed roller 115 and the separation roller 116. Therefore, it takes a certain amount of time from when the third motor 133 is driven until the regulating guide 112 and the flap 114 move and the medium comes into contact with the feed roller 115 and the separation roller 116. The control unit 151 can shorten the time required to feed the medium by driving the third motor 133 to start the movement of the regulating guide 112 and the flap 114 before driving the first motor 131 to start the rotation of the feed roller 115.

[0082] Note that the control unit 151 may wait a first predetermined time after driving the third motor 133 in step S103 before driving the first motor 131 in step S105. The first predetermined time is set to the time from driving the third motor 133 until the leading edge of the medium restricted by the flap 114 comes into contact with the separation roller 116 rotating in the opposite direction to the medium feeding direction. This allows the control unit 151 to reliably apply a separation force by the separation roller 116 to the medium group before the feeding force by the feed roller 115 is applied, and makes it possible to more reliably prevent the occurrence of double feeding of media.

[0083] As described above, the shaft 116a of the separation roller 116 is provided with the torque limiter 116c. Depending on the arrangement position of the torque limiter 116c, there may be a gap (backlash component) between the shaft 116a and (the outer peripheral surface 116b of) the separation roller 116, through which the driving force is not transmitted. Therefore, depending on the arrangement position of the torque limiter 116c, it may take some time for the driving force from the second motor 132 to be transmitted to the separation roller 116. The control unit 151 can remove the gap (backlash component) between the shaft 116a and the separation roller 116 by driving the second motor 132 to start the rotation of the separation roller 116 before driving the first motor 131 to start the rotation of the feed roller 115. This allows the control unit 151 to reliably apply the separation force of the separation roller 116 to the medium group before the feeding force of the feed roller 115 is applied, thereby suppressing the occurrence of double feeding of media.

[0084] Note that the control unit 151 may wait a second predetermined time from driving the second motor 132 in step S104 until driving the first motor 131 in step S105. The second predetermined time is set to a time from driving the second motor 132 until the separation roller 116 is reliably rotated. This allows the control unit 151 to more reliably suppress the occurrence of double feeding of media.

[0085] Next, control unit 151 waits until the leading edge of the transported medium passes the position of second medium sensor 117 (step S106). Control unit 151 periodically acquires a second medium signal from second medium sensor 117, and determines that the leading edge of the medium has passed the position of second medium sensor 117 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.

[0086] Next, the control unit 151 controls the second motor 132 to stop the separation roller 116 (step S107).

[0087] 10, time T4 indicates the time when the signal value of the second medium signal changes from L to H, i.e., the time when the leading edge of the medium passes the position of second medium sensor 117. As shown in FIG. 10, rotation of separation roller 116 is stopped when the leading edge of the medium passes the position of second medium sensor 117. When the leading edge of the medium passes the position of second medium sensor 117, it has already passed through the nip portion between feed roller 115 and separation roller 116, and separation of the medium is complete. Therefore, by stopping separation roller 116, control unit 151 can reduce the power consumption and device temperature of medium conveying device 100 while properly separating the medium.

[0088] Next, control unit 151 waits until the leading edge of the transported medium passes the position of transport rollers 119 (step S108). Control unit 151 periodically acquires a third medium signal from third medium sensor 121, and determines that the leading edge of the medium has passed the position of third medium sensor 121 when the signal value of the third medium signal changes from a value indicating that the medium is not present to a value indicating that the medium is present. Control unit 151 determines that the leading edge of the medium has passed the position of transport rollers 119 when the leading edge of the medium has passed the position of third medium sensor 121.

[0089] Next, the control unit 151 controls the first motor 131 to stop the feeding roller 115 (step S109).

[0090] 10, time T5 indicates the time when the signal value of the third medium signal changes from L to H, i.e., the time when the leading edge of the medium passes the position of third medium sensor 121. As shown in FIG. 10, after the leading edge of the medium passes the position of third medium sensor 121, control unit 151 stops feed roller 115. As a result, the medium is thereafter transported by transport roller 119, and feed roller 115 rotates along with the transported medium. By stopping feed roller 115, control unit 151 can prevent the medium from being pushed by feed roller 115 and bending between feed roller 115 and transport roller 119, causing a medium jam.

[0091] Next, the control unit 151 causes the imaging device 122 to start imaging the medium (step S110).

[0092] Next, control unit 151 waits until the rear end of the transported medium passes the position of second medium sensor 117 (step S111). Control unit 151 periodically acquires a second medium signal from second medium sensor 117, and determines that the rear end of the medium has passed the position of second medium sensor 117 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.

[0093] Next, control unit 151 determines whether or not a medium remains on mounting table 103 based on the first medium signal received from first medium sensor 111 (step S112).

[0094] If the medium remains on the placement table 103, the control unit 151 controls the second motor 132 to rotate the separation roller 116 again in the direction opposite to the medium feeding direction (the direction of the arrow A5 in FIG. 2) (step S113).

[0095] Next, the control unit 151 controls the first motor 131 to rotate the feed roller 115 again in the medium feed direction (the direction of the arrow A4 in FIG. 2) to feed the succeeding medium (step S114).

[0096] 10, time T6 indicates the time when the signal value of the second medium signal changes from H to L, i.e., the time when the rear end of the medium passes the position of second medium sensor 117. As described above, control unit 151 starts driving second motor 132 and first motor 131 in that order, so separation roller 116 and feed roller 115 start rotating successively at times T6 and T7.

[0097] This allows the control unit 151 to apply a separation force by the separation roller 116 to the group of media remaining on the mounting table 103 before the feeding force by the feed roller 115 is applied. Therefore, the leading ends of the group of media remaining on the mounting table 103 are separated by the separation roller 116, which rotates in the opposite direction to the medium feeding direction, so that the upper media are positioned upstream before entering the nip portion between the feed roller 115 and the separation roller 116. Therefore, when the feed roller 115 starts to rotate, multiple media enter the nip portion between the feed roller 115 and the separation roller 116 together, preventing double feeding of media.

[0098] In addition, by starting to rotate the separation roller 116 before the feed roller 115 starts to rotate, the separation roller 116 is prevented from being driven by the feed roller 115 before starting to rotate, and the separation roller 116 can separate the medium well.

[0099] In this manner, the control unit 151 controls the first motor 131 and the second motor 132 to rotate the separation roller 116 and then the feed roller 115 when starting to feed the second or subsequent medium among the media set in the regulating guide 112. This allows the control unit 151 to prevent the occurrence of multiple feeding of media when starting to feed the second or subsequent medium as well.

[0100] Next, control unit 151 waits until the rear end of the preceding medium passes the imaging position of imaging device 122 (step S115). Control unit 151 periodically acquires a third medium signal from third medium sensor 121, and determines that the rear end of the preceding medium has passed the position of third medium sensor 121 when the signal value of the third medium signal changes from a value indicating the presence of a medium to a value indicating the absence of a medium. Control unit 151 determines that the rear end of the preceding medium has passed the imaging position when a third predetermined time has elapsed since the rear end of the preceding medium passed the position of third medium sensor 121. 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 third medium sensor 121 to the imaging position.

[0101] Next, the control unit 151 acquires an input image from the imaging device 122, and outputs the acquired input image by transmitting it to the information processing device via the interface device 135 (step S116).

[0102] Next, the control unit 151 returns the process to step S106, and repeats the processes from step S106 onwards for the succeeding medium. In this case, in step S106, the control unit 151 waits until the leading edge of the succeeding medium passes the position of the second medium sensor 117 (time T8 in FIG. 10), and in step S107, controls the second motor 132 to stop the separation roller 116. Furthermore, in step S108, the control unit 151 waits until the leading edge of the succeeding medium passes the position of the transport roller 119 (time T9 in FIG. 10), and in step S109, controls the first motor 131 to stop the feed roller 115.

[0103] On the other hand, if no media remain on the mounting table 103 in step S112, the control unit 151 waits until the rear end of the transported medium passes the imaging position of the imaging device 122, similar to the process of step S115 (step S117).

[0104] Next, the control unit 151 acquires an input image from the imaging device 122, and outputs the acquired input image by transmitting it to the information processing device via the interface device 135 (step S118).

[0105] Next, control unit 151 waits until the trailing end of the transported medium passes the position of discharge rollers 123 (step S119). Control unit 151 determines that the trailing end of the medium has passed the position of discharge rollers 123 when a fourth predetermined time has elapsed since the trailing end of the medium passed the position of third medium sensor 121. The fourth 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 third medium sensor 121 to the position of discharge rollers 123.

[0106] Next, the control unit 151 controls the third motor 133 to stop the conveying roller 119, the first opposing roller 120, the discharge roller 123 and / or the second opposing roller 124 (step S120).

[0107] Next, the control unit 151 controls (reversely rotates) the third motor 133 so as to rotate the cam member 113 in the opposite direction of the arrow A11 in Fig. 3 to move the regulating guide 112 in the opposite direction of the arrow A12 in Fig. 3, that is, from the release position to the set position (step S121). As a result, the regulating guide 112 is disposed at the set position, and the flap 114 engages with the regulating guide 112 disposed at the set position, and is disposed at a position (position shown in Fig. 3) that prevents the medium from entering the nip portion between the feed roller 115 and the separation roller 116. At this time, the conveying roller 119, the first opposing roller 120, the discharge roller 123 and / or the second opposing roller 124 rotate in the opposite direction of the arrows A6, A7, A8 and A9 in Fig. 2, respectively, but no problem occurs because no medium is present in the medium conveying path.

[0108] Next, the control unit 151 controls the third motor 133 to stop the cam member 113 (step S122).

[0109] Next, the control unit 151 controls the first motor 131 or the second motor 132 to rotate the feed roller 115 or the separation roller 116 (step S123). The control unit 151 controls the first motor 131 or the second motor 132 to rotate either or both of the feed roller 115 and the separation roller 116 in the medium feed direction. The control unit 151 rotates either one of the feed roller 115 and the separation roller 116, thereby allowing the other roller to be rotated.

[0110] That is, when the medium is not being fed, the control unit 151 controls the first motor 131 or the second motor 132 to rotate the feed roller 115 or the separation roller 116 with the regulating guide 112 disposed at the set position. The control unit 151 rotates the feed roller 115 or the separation roller 116 to move the attachments attached to the feed roller 115 or the separation roller 116. As the feed roller 115 and the separation roller 116 rotate, the attachments attached to the feed roller 115 or the separation roller 116 from the medium being fed fall off the feed roller 115 or the separation roller 116 and are stored in the storage unit 134. As the feed roller 115 and the separation roller 116 rotate, the attachments attached to each roller or the attachments accumulated around each roller are dispersed. This ensures a sufficient contact area between the medium and the rubber portion of each roller, and the medium conveying device 100 can suppress a decrease in the medium feeding and separating forces.

[0111] Next, the control unit 151 controls the first motor 131 or the second motor 132 to stop the feeding roller 115 or the separation roller 116 (step S124), and ends the series of steps.

[0112] The processes of steps S103, S104, and S105 may be performed in any order. The processes of steps S113 and S114 may be performed in any order. The processes of steps S123 and S124 may be performed at any timing when the medium is not being fed. Alternatively, the processes of steps S123 and S124 may be omitted.

[0113] FIG. 11 is a flowchart showing an example of the operation of the multifeed determination process of the medium conveying device 100.

[0114] An example of the operation of the multifeed determination process of the medium conveying device 100 will be described below with reference to the flowchart shown in Fig. 11. The flow of the operation described below is executed mainly by the processing circuit 150 in cooperation with each element of the medium conveying device 100 based on a program previously stored in the storage device 140. The flow of the operation shown in Fig. 11 is executed periodically during medium conveyance.

[0115] First, the determination unit 152 acquires an ultrasonic signal from the ultrasonic sensor 118 (step S201).

[0116] Next, the determination unit 152 determines whether or not a multi-feed of media has occurred based on the acquired ultrasonic signal (step S202). If the signal value of the ultrasonic signal is equal to or greater than the multi-feed threshold, the determination unit 152 determines that a multi-feed of media has not occurred, and if the signal value of the ultrasonic signal is less than the multi-feed threshold, the determination unit 152 determines that a multi-feed of media has occurred. The multi-feed threshold is set to a value between the signal value of the ultrasonic signal when a single sheet of paper is being conveyed and the signal value of the ultrasonic signal when a multi-feed of paper has occurred. If it is determined that a multi-feed of media has not occurred, the determination unit 152 returns to step S201 and repeats the processes of steps S201 to S202.

[0117] On the other hand, if the determining unit 152 determines that a multi-feed of media has occurred, the control unit 151 temporarily stops the medium reading process (step S203).

[0118] Next, the control unit 151 controls the first motor 131 and the second motor 132 to stop the feeding roller 115 and the separation roller 116 (step S204). The determination unit 152 detects that a multi-feed of media has occurred when the leading edge of the medium fed in a multi-feed passes the position of the ultrasonic sensor 118. At this time, the leading edge of the medium has not reached the position of the conveying roller 119. Therefore, the control unit 151 controls the third motor 133 to continue rotating the conveying roller 119, the first opposing roller 120, the discharge roller 123, and / or the second opposing roller 124. This allows the control unit 151 to continue conveying the medium that was fed before the medium fed in a multi-feed.

[0119] Next, the control unit 151 controls the second motor 132 to rotate the separation roller 116 again in the direction opposite to the medium feeding direction (in the direction of the arrow A5 in FIG. 2) (step S205).

[0120] Next, the control unit 151 controls (reversely rotates) the first motor 131 to rotate the feed roller 115 in the opposite direction to the medium feeding direction (opposite direction of the arrow A4 in FIG. 2), thereby returning the media fed in a double feed to the placement table 103 (step S206). The control unit 151 controls the first motor 131 and the second motor 132 so that the circumferential speed of the shaft 115a which is the rotation axis of the feed roller 115 is higher than the circumferential speed of the outer circumferential surface 115b of the feed roller 115 which is driven by the separation roller 116.

[0121] In this way, when the determination unit 152 determines that a duplicated medium feed has occurred, the control unit 151 controls the first motor 131 and the second motor 132 to return the medium to the mounting table 103. The control unit 151 controls the first motor 131 and the second motor 132 to rotate the separation roller 116 and then the feed roller 115 when returning ... so that the circumferential speed of the shaft 115a which is the rotation axis of the feed roller 115 is higher than the circumferential speed of the outer circumferential surface 115b of the feed roller 115 which is driven by the separation roller 116 when returning the medium to the mounting table 103.

[0122] Fig. 12 is a schematic diagram for explaining the operation of returning the overlapped medium M2 to the placement table 103. Fig. 12 is a schematic diagram of the feeding roller 115 and the separation roller 116 as viewed from the side when overlapped feeding has occurred.

[0123] As described above, the limit value of the torque limiter 116c provided on the shaft 116a of the separation roller 116 is set to a value such that the rotational force is transmitted via the torque limiter 116c when there are multiple media. When the shaft 115a, which is the rotation axis of the feed roller 115, is rotated in the direction A21 opposite to the medium feeding direction, the outer circumferential surface 115b of the feed roller 115 does not rotate according to the driving force from the first motor 131 due to the action of the one-way clutch 115c. The outer circumferential surface 115b of the feed roller 115 rotates in the direction A22 opposite to the medium feeding direction, following the separation roller 116.

[0124] The shaft 115a of the feed roller 115 is provided to rotate at a circumferential speed faster than the circumferential speed of the outer circumferential surface 115b of each feed roller 115 which rotates following the separation roller 116. As a result, the outer circumferential surface 115b of the feed roller 115 rotates following the rotation of the outer circumferential surface 116b of the separation roller 116 without being hindered by the one-way clutch 115c. In this way, the feed roller 115 is provided to rotate in the opposite direction A22 to the medium feeding direction following the separation roller 116. Also, the separation roller 116 rotates in the opposite direction A5 to the medium feeding direction without being subjected to a load by the feed roller 115.

[0125] Therefore, even if multiple media M2 are fed in a duplicated manner between the separation roller 116 and the feed roller 115, the media conveying device 100 can return all of the multiple media M2 to the mounting table 103 by reversing the rotation of the first motor 131.

[0126] As described above, the shaft 116a of the separation roller 116 is provided with the torque limiter 116c, and depending on the position of the torque limiter 116c, there may be a backlash component between the shaft 116a and the separation roller 116 that does not transmit the driving force. Therefore, if the shaft 115a of the feed roller 115 is rotated before the separation roller 116, the shaft 115a of the feed roller 115 may start rotating in a state in which the separation roller 116 is not locked. In this case, the medium is not sufficiently fixed by the separation roller 116 and is in an unstable state, and wrinkles may occur in the medium in contact with the feed roller 115 (the medium located at the bottom) when the shaft 115a of the feed roller 115 starts to rotate. Furthermore, the separation roller 116 starts rotating in a state in which the outer circumferential surface 115b of the feed roller 115 is not locked. The medium is not sufficiently fixed by the outer peripheral surface 115b of the feed roller 115 and is in an unstable state, so that wrinkles may occur in the medium in contact with the separation roller 116 (the uppermost medium) when the separation roller 116 starts to rotate.

[0127] The medium conveying device 100 rotates the separation roller 116 and then rotates the shaft 115a of the feed roller 115. As a result, when the separation roller 116 starts to rotate, the outer peripheral surface 115b of the feed roller 115 is supported by the shaft 115a of the feed roller 115, and the medium is in a stable state by the feed roller 115. Therefore, the medium conveying device 100 can suppress the occurrence of wrinkles in the medium in contact with the separation roller 116 (the medium located at the top). Furthermore, when the shaft 115a of the feed roller 115 starts to rotate, there is no play between the separation roller 116 and the shaft 116a, and the medium is in a stable state by the separation roller 116. Therefore, the medium conveying device 100 can suppress the occurrence of wrinkles in the medium in contact with the feed roller 115 (the medium located at the bottom).

[0128] The control unit 151 may wait a fifth predetermined time from re-rotating the separation roller 116 in step S205 until rotating the feed roller 115 in reverse in step S206. The fifth predetermined time is set to a time for the separation roller 116 to rotate by the amount of the backlash component between the separation roller 116 and the shaft 116a. This allows the control unit 151 to start rotating the shaft 115a of the feed roller 115 after the backlash component between the separation roller 116 and the shaft 116a has been completely eliminated, and the occurrence of wrinkles in the medium can be more reliably suppressed.

[0129] Next, the control unit 151 waits until the medium returns to the mounting table 103 (step S207). The control unit 151 periodically acquires a second medium signal from the second medium sensor 117, and determines that the downstream end of the medium traveling in the reverse direction has passed the position of the second medium sensor 117 when the signal value of the second medium signal changes from a value indicating the presence of the medium to a value indicating the absence of the medium. The control unit 151 determines that the medium has returned to the mounting table 103 when a sixth predetermined time has elapsed since the downstream end of the medium passed the position of the second medium sensor 117. The sixth predetermined time is set to a value obtained by adding a margin to the time required for the medium traveling in the reverse direction to move from the position of the second medium sensor 117 to the upstream end of the nip portion between the feed roller 115 and the separation roller 116.

[0130] Next, the control unit 151 controls the first motor 131 and the second motor 132 to stop the feeding roller 115 and the separation roller 116 (step S208).

[0131] Next, the control unit 151 resumes the medium reading process (step S209). Since the transport roller 119, the first opposing roller 120, the discharge roller 123 and / or the second opposing roller 124 are already rotating, the control unit 151 resumes the medium reading process from the process of step S104 in Fig. 8. The control unit 151 also returns the process to step S201, and repeats the processes of steps S201 to S209.

[0132] The feed roller 115 may not have the one-way clutch 115c, and the outer circumferential surface 115b may be provided so as to rotate in accordance with the rotation of the shaft 115a. In this case, the control unit 151 controls the second motor 132 in step S205 to rotate the separation roller 116 again in the direction opposite to the medium feeding direction, and controls the first motor 131 in step S206 to rotate the feed roller 115 in the direction opposite to the medium feeding direction. That is, when returning the medium to the mounting table 103, the control unit 151 controls the first motor 131 and the second motor 132 to rotate the separation roller 116 and then the feed roller 115. However, the control unit 151 controls the first motor 131 and the second motor 132 so that the moving speed of the outer circumferential surface 115b of the feed roller 115 is higher than the moving speed of the outer circumferential surface 116b of the separation roller 116 when returning the medium to the mounting table 103.

[0133] In this case too, when multiple media M2 are fed in a overlapping manner between the separation roller 116 and the feed roller 115, the media conveying device 100 can return all of the multiple media M2 to the mounting table 103 by rotating the first motor 131 in the reverse direction.

[0134] When a duplicated medium feed occurs, the duplicated medium is present above the lowest medium in contact with the feed roller 115, and the gravity of the duplicated medium is applied to the medium in contact with the feed roller 115. Therefore, when the feed roller 115 is rotated before the separation roller 116 is rotated, the lowest medium is subjected to a downward force due to the gravity of the duplicated medium and a force toward the upstream side due to the feed roller 115. Therefore, a force is applied to the lowest medium in a manner that twists the medium, which may cause wrinkles.

[0135] The medium conveying device 100 rotates the separation roller 116 and then rotates the feed roller 115. There is no medium above the uppermost medium in contact with the separation roller 116. Therefore, when the separation roller 116 is rotated before the feed roller 115 is rotated, only the force of the separation roller 116 toward the upstream side is applied to the medium in contact with the separation roller 116, so that wrinkles are less likely to occur. Therefore, the medium conveying device 100 can suppress the occurrence of wrinkles in the medium by rotating the separation roller 116 and then rotating the feed roller 115.

[0136] Furthermore, the control unit 151 makes the moving speed of the outer circumferential surface 115b of the feed roller 115 higher than the moving speed of the outer circumferential surface 116b of the separation roller 116. This enables the control unit 151 to make the lowest medium in contact with the feed roller 115 catch up with the highest medium in contact with the separation roller 116. This enables the control unit 151 to synchronize the timing for returning the media fed in a multi-feed to the placement table 103, making it possible to complete the recovery of the media early.

[0137] The control unit 151 may control the first motor 131 and the second motor 132 so that the amount of rotation of the separation roller 116 (the amount of movement of the outer circumferential surface 116b) is greater than the amount of rotation of the feed roller 115 (the amount of movement of the outer circumferential surface 115b). By increasing the amount of rotation of the separation roller 116, the control unit 151 can more reliably return the upper medium fed together with the medium to be fed to the placement table 103. Furthermore, by reducing the amount of rotation of the feed roller 115, the control unit 151 can prevent the lower medium from being returned too far, causing wrinkles in the medium.

[0138] Furthermore, the medium conveying device 100 does not need to execute the multifeed determination process.

[0139] As described above in detail, in the medium conveying device 100, the first motor 131 for driving the feed roller 115, the second motor 132 for driving the separation roller 116, and the third motor 133 for driving the regulating guide 112 are separately provided. In the medium conveying device 100, when feeding of the medium starts, the first motor 131, the second motor 132, and the third motor 133 are controlled so that the separation roller 116 in a rotating state comes into contact with the medium before the feed roller 115 rotates. This enables the medium conveying device 100 to properly separate the leading ends of the medium group placed on the placement table 103 by the separation roller 116, and thus enables the media to be separated more effectively.

[0140] Furthermore, in the medium conveying device 100, a first motor 131 for driving the feed roller 115 and a second motor 132 for driving the separation roller 116 are separately provided. When returning the medium to the mounting table 103 in the event of a double feed, the medium conveying device 100 controls the first motor 131 and the second motor 132 so as to rotate the separation roller 116 and then rotate the shaft 115a of the feed roller 115. This enables the medium conveying device 100 to stably return the medium that has been fed in a double feed to the mounting table 103, and makes it possible to more appropriately recover the medium in the event of a double feed of media.

[0141] Furthermore, medium conveying device 100 is now able to stably separate media regardless of the number of media being conveyed together or the type of media being conveyed, and stably return media that have been fed in a double feed to mounting table 103. Furthermore, medium conveying device 100 is now able to prevent media jams from occurring when returning media that have been fed in a double feed to mounting table 103.

[0142] FIG. 13 is a diagram for explaining a transport path inside a medium transport device 200 according to another embodiment.

[0143] The medium conveying device 200 has each part of the medium conveying device 100. However, the medium conveying device 200 has a second motor 232, a third motor 233, a second transmission mechanism 232a, and a third transmission mechanism 233a instead of the second motor 132, the third motor 133, the second transmission mechanism 132a, and the third transmission mechanism 133a.

[0144] The second motor 232 and the second transmission mechanism 232a have the same configuration as the second motor 132 and the second transmission mechanism 132a, respectively. However, the second motor 232 is connected to the separation roller 116 and the cam member 113 via the second transmission mechanism 232a, and drives the separation roller 116 and the cam member 113. The second motor 232 generates a driving force for driving the separation roller 116 and the cam member 113 by a control signal from the processing circuit 150. The second transmission mechanism 232a includes one or more pulleys, belts, gears, etc. provided between the second motor 232 and the shaft 116a, which is the rotation shaft of the separation roller 116, and the rotation shaft 113a of the cam member 113. In particular, one or more gears are provided between the shaft 116a of the separation roller 116 and the rotation shaft 113a of the cam member 113 to make the rotation direction of the separation roller 116 different from the rotation direction of the cam member 113. The second transmission mechanism 232a transmits the driving force generated by the second motor 232 to the separation roller 116 and the cam member 113. As a result, the second motor 232 rotates the separation roller 116, causing the separation roller 116 to separate, feed, and transport the medium. The second motor 232 also rotates the cam member 113, moving the regulating guide 112 that abuts against the cam member 113. That is, in the medium transport device 200, the cam member 113 is provided rotatably by the second motor 232, and the regulating guide 112 is provided movably by the second motor 232.

[0145] The third motor 233 and the third transmission mechanism 233a have the same configuration as the third motor 133 and the third transmission mechanism 133a, respectively. However, the third motor 233 is connected to the conveying roller 119 and the discharge roller 123 via the third transmission mechanism 233a, but is not connected to the cam member 113. The third motor 233 generates a driving force for driving the conveying roller 119 and the discharge roller 123 in response to a control signal from the processing circuit 150. The third transmission mechanism 233a includes one or more pulleys, belts, gears, etc. provided between the third motor 233 and the shaft 119a which is the rotation shaft of the conveying roller 119 and the shaft 123a which is the rotation shaft of the discharge roller 123. The third transmission mechanism 133a transmits the driving force generated by the third motor 133 to the conveying roller 119 and the discharge roller 123. As a result, the third motor 133 rotates the transport rollers 119 and the discharge rollers 123, causing the transport rollers 119 and the discharge rollers 123 to transport and discharge the medium.

[0146] In the medium conveying device 200, the control unit 151 and the determination unit 152 execute the medium reading process shown in FIGS. 8 and 9, and the multiple feed determination process shown in FIG.

[0147] In step S103, the control unit 151 drives the third motor 233 to rotate the conveying roller 119, the first opposing roller 120, the discharge roller 123, and / or the second opposing roller 124. In step S104, the control unit 151 drives the second motor 232 to rotate the separation roller 116 and rotate the cam member 113 to move the regulating guide 112 from the set position to the release position. In step S105, the control unit 151 drives the first motor 131 to rotate the feed roller 115. As a result, the control unit 151 controls the first motor 131 and the second motor 232 so that the separation roller 116 in the rotated state comes into contact with the medium before the feed roller 115 rotates at the start of feeding the medium. In addition, the control unit 151 operates the second motor 232 before operating the first motor 131 at the start of feeding the medium.

[0148] In step S107, the control unit 151 controls the second motor 232 to stop the separation roller 116, and in step S113, the control unit 151 controls the second motor 232 to re-rotate the separation roller 116. In these operations, the regulating guide 112 does not move from the release position. In addition, in step S114, the control unit 151 controls the first motor 131 to re-rotate the feed roller 115. As a result, the control unit 151 controls the first motor 131 and the second motor 232 to rotate the separation roller 116 and then rotate the feed roller 115 at the start of feeding the second or subsequent medium among the media set in the regulating guide 112.

[0149] In step S120, the control unit 151 controls the third motor 233 to stop the conveying roller 119, the first opposing roller 120, the discharge roller 123 and / or the second opposing roller 124. In step S121, the control unit 151 controls the second motor 232 to rotate the cam member 113 to move the regulating guide 112 from the release position to the set position. At this time, the separation roller 116 rotates in the medium feeding direction, but since there is no medium on the placement table 103, no problem occurs.

[0150] In step S123, the control unit 151 controls the first motor 131 to rotate the feed roller 115. That is, when the medium is not being fed, the control unit 151 controls the first motor 131 or the second motor 232 to rotate the feed roller 115 with the regulating guide 112 placed at the set position. The control unit 151 rotates the feed roller 115 to move any attached matter attached to the feed roller 115 or the separation roller 116. In step S124, the control unit 151 controls the first motor 131 to stop the feed roller 115.

[0151] Furthermore, in steps S204, S205, and S208 of the double feeding determination process, the control unit 151 controls the second motor 232 to stop or restart the separation roller 116. In these steps, the restriction guide 112 does not move from the release position.

[0152] As described above in detail, the medium conveying device 200 is able to separate the media better even when the separation roller 116 and the regulating guide 112 are driven by the common second motor 232. Also, the medium conveying device 200 is able to more appropriately recover the media when multiple media are fed, even when the separation roller 116 and the regulating guide 112 are driven by the common second motor 232.

[0153] 14 is a diagram showing a schematic configuration of a processing circuit 350 in a medium conveying device according to yet another embodiment. The processing circuit 350 is used in place of the processing circuit 150 of the medium conveying devices 100 and 200, and executes medium reading processing, multiple feed determination processing, and the like in place of the processing circuit 150. The processing circuit 350 has a control circuit 351, a determination circuit 352, and the like. Note that each of these units may be composed of an independent integrated circuit, microprocessor, firmware, and the like.

[0154] The control circuit 351 is an example of a control unit, and has the same functions as the control unit 151. The control circuit 351 receives an operation signal from the operation device 105 or the interface device 135, a first medium signal from the first medium sensor 111, a second medium signal from the second medium sensor 117, and a third medium signal from the third medium sensor 121. The control circuit 351 also receives a determination result of multiple feeding of media from the determination circuit 352. The control circuit 351 controls the first motor 131, the second motor 132 or 232, and the third motor 133 or 233 based on each piece of received information, and also obtains an input image from the imaging device 122 and outputs it to the interface device 135.

[0155] The determination circuit 352 is an example of a determination unit, and has the same function as the determination unit 152. The determination circuit 352 receives an ultrasonic signal from the ultrasonic sensor 118, determines whether or not a duplicated feed of media has occurred based on the received ultrasonic signal, and outputs the determination result to the control circuit 351.

[0156] As described above in detail, the medium conveying device is now able to separate the media better even when using the processing circuit 350. Also, the medium conveying device is now able to more appropriately recover the media when a duplicated medium feed occurs even when using the processing circuit 350. [Explanation of symbols]

[0157] 100, 200 medium conveying device, 103 placement table, 112 regulating guide, 113 cam member, 115 feeding roller, 115c one-way clutch, 116 separation roller, 116c torque limiter, 119 conveying roller, 131 first motor, 132, 232 second motor, 133, 233 third motor, 151 control unit, 152 determination unit

Claims

1. A mounting table; a feeding roller for feeding the medium placed on the placement table; a separation roller disposed opposite the feed roller; a first motor that generates a first driving force for driving the feed roller; a second motor that generates a second driving force for driving the separation roller; a first transmission unit that transmits the first driving force to the feed roller; a second transmission unit that transmits the second driving force to the separation roller; a determination unit that determines whether or not a duplicate feed of media has occurred; a control unit that controls the first motor and the second motor to return the medium to the placement table when the determination unit determines that a multifeed of the medium has occurred, the control unit controls the first motor and the second motor so as to rotate the separation roller and then the feed roller when returning the medium to the placement table; At least one of the first transmission part and the second transmission part has a backlash component. A medium transport device comprising:

2. a one-way clutch that is disposed on a rotation shaft of the feed roller and restricts the feed roller from rotating in a direction opposite to the medium feed direction with respect to the rotation shaft; 2. The medium transport device of claim 1, wherein the control unit controls the first motor and the second motor so that, when returning the medium to the placement table, the peripheral speed of the rotating shaft of the feed roller is higher than the peripheral speed of the outer circumferential surface of the feed roller that is driven by the separation roller.

3. 2. The medium transport device of claim 1, wherein the control unit controls the first motor and the second motor so that, when returning the medium to the placement table, the movement speed of the outer surface of the feed roller is higher than the movement speed of the outer surface of the separation roller.

4. a regulating guide that is movable between a first position that regulates contact of the medium with the feed roller and the separation roller and a second position that does not regulate contact of the medium with the feed roller and the separation roller; a conveying roller disposed downstream of the feed roller and the separation roller in a medium conveying direction; 4. The medium transport device according to claim 1, further comprising: a third motor for moving the regulating guide and driving the transport roller.

5. A feeding roller feeds the medium placed on the placement table, Determine whether a media double feed has occurred; when it is determined that a duplicated medium feed has occurred, a first motor that generates a first driving force for driving the feed roller and a second motor that generates a second driving force for driving a separation roller disposed opposite the feed roller are controlled so as to stop the medium once and then return it to the placement table; controlling the first motor and the second motor so as to rotate the separation roller and then the feed roller when returning the medium to the placement table; a backlash component is present in at least one of a first transmission unit that transmits the first driving force to the feed roller and a second transmission unit that transmits the second driving force to the separation roller; A medium feeding method comprising:

6. 1. A control program for a medium transport device having a mounting table, a feed roller for feeding a medium mounted on the mounting table, a separation roller disposed opposite the feed roller, a first motor for generating a first driving force for driving the feed roller, a second motor for generating a second driving force for driving the separation roller, a first transmission unit for transmitting the first driving force to the feed roller, and a second transmission unit for transmitting the second driving force to the separation roller, Determine whether a media double feed has occurred; When it is determined that a duplicated medium feed has occurred, the first motor and the second motor are controlled so as to stop the medium once and then return it to the placement table; causing the medium transport device to control the first motor and the second motor so as to rotate the separation roller and then the feed roller when returning the medium to the placement table; At least one of the first transmission part and the second transmission part has a backlash component. A control program comprising:

Images