MEDIUM CONVEYING DEVICE, MEDIUM FEEDING METHOD, AND CONTROL PROGRAM

TECHNICAL FIELD

The present disclosure relates to a medium conveying apparatus, a medium feeding method, and a control program.

BACKGROUND

In a medium conveying apparatus such as a scanner that sequentially feed and image a plurality of media while separating the media, it is preferable to more satisfactorily separate media in order not to cause multi feed of media.

A document separation apparatus including a feed roller, a reverse roller, a lever to detect a document on a document table, and a reading motor to rotate the reverse roller, based on detection information of the lever, is known. In the document separation apparatus, when the reading motor detects a document on the document table by the lever, the document separation apparatus rotates the reverse roller without rotating the feed roller.

A feeding apparatus including a supporting part that supports a medium set on a setting part and, when feeding a medium by a feed roller, moves such that the medium comes into contact with the feed roller is known. In the document feeding apparatus, when feeding the medium by the feed roller, the feeding apparatus drives the feed roller before movement of the supporting part.

SUMMARY

A medium conveying apparatus according to an embodiment includes a feed roller to feed a medium, a separation roller located to face the feed roller, a regulating guide provided to be movable between a first position where contact of the medium with the feed roller and the separation roller is regulated and a second position where contact of the medium with the feed roller and the separation roller is not regulated, and a processor to control the feed roller, the separation roller, and the regulating guide. When feeding of a medium is started, processor controls the feed roller, the separation roller, and the regulating guide such that the feed roller feeds the medium after the regulating guide moves from the first position toward the second position and the separation roller contacts the medium.

A method for feeding a medium according to an embodiment includes, when feeding of a medium is started, controlling a feed roller for feeding a medium, a separation roller located to face the feed roller, and a regulating guide provided to be movable between a first position where contact of the medium with the feed roller and the separation roller is regulated and a second position where contact of the medium with the feed roller and the separation roller is not regulated such that the feed roller feeds the medium after the regulating guide moves from the first position toward the second position and the separation roller contacts the medium

A computer-readable, non-transitory medium storing executable instructions for feeding a medium according to an embodiment includes, when feeding of a medium is started, controlling a feed roller for feeding a medium, a separation roller located to face the feed roller, and a regulating guide provided to be movable between a first position where contact of the medium with the feed roller and the separation roller is regulated and a second position where contact of the medium with the feed roller and the separation roller is not regulated such that the feed roller feeds the medium after the regulating guide moves from the first position toward the second position and the separation roller contacts the medium.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating a medium conveying apparatus according to an embodiment.

FIG. 2 is a diagram for illustrating a conveyance path inside the medium conveying apparatus.

FIG. 3 is a schematic diagram for illustrating a regulating guide, etc.

FIG. 4 is a schematic diagram for illustrating operation of the regulating guide.

FIG. 5 is a schematic diagram for illustrating a holding part.

FIG. 6 is a block diagram illustrating a schematic configuration of the medium conveying apparatus.

FIG. 7 is a diagram illustrating a schematic configuration of a storage device and a processing circuit.

FIG. 8 is a flowchart illustrating an operation example of medium reading process.

FIG. 9 is a flowchart illustrating the operation example of the medium reading process.

FIG. 10 is a graph for illustrating changes in the speeds of a feed roller, etc.

FIG. 11 is a flowchart illustrating an operation example of multi feed determination process.

FIG. 12 is a schematic diagram for illustrating an operation of returning a medium to a loading tray.

FIG. 13 is a diagram for illustrating a conveyance path inside another medium conveying apparatus.

FIG. 14 is a diagram illustrating a schematic configuration of another processing circuit.

DESCRIPTION OF EMBODIMENTS

The object and advantages of the invention will be realized and attained by means of the elements and combinations, in particular, described in the claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, and are not restrictive of the invention as claimed.

Hereinafter, a medium conveying apparatus, a method for feeding a medium, and a computer-readable, non-transitory medium storing executable instructions according to an embodiment, will be described with reference to the drawings. However, it should be noted that the technical scope of the invention is not limited to these embodiments, and extends to the inventions described in the claims and their equivalents.

FIG. 1 is a perspective view illustrating an example of a medium conveying apparatus configured as an image scanner. The medium conveying apparatus 100 conveys and images a medium being a document. Examples of a medium include paper, thin paper, thick paper, a card, a booklet, and a passport. The medium conveying apparatus 100 may be a facsimile, a copying machine, a multifunctional peripheral (MFP), etc. A conveyed medium may be an object being printed on, etc., instead of a document, and the medium conveying apparatus 100 may be a printer, etc.

The medium conveying apparatus 100 includes a lower housing 101, an upper housing 102, a loading tray 103, an ejection tray 104, an operation device 105, a display device 106, etc. In FIG. 1, an arrow A1 indicates a medium conveying direction, an arrow A2 indicates a width direction perpendicular to the medium conveying direction, and an arrow A3 indicates a high direction perpendicular to the medium conveying direction A1 and the width direction. Hereinafter, upstream refers to upstream in the medium conveying direction A1, and downstream refers to downstream in the medium conveying direction A1.

The upper housing 102 is located at a position covering the top surface of the medium conveying apparatus 100 and is engaged with the lower housing 101 to be rotatable by a hinge to be openable when, for example, a medium is stuck or cleaning of the inside of the medium conveying apparatus 100 is performed.

The loading tray 103 is engaged with the lower housing 101 and places a medium to be fed and conveyed. The ejection tray 104 is engaged with the upper housing 102 and places an ejected medium. The ejection tray 104 may be engaged with the lower housing 101.

The operation device 105 includes an input device such as a button, and an interface circuit acquiring a signal from the input device, accepts an input operation by a user, and outputs an operation signal based on the input operation by the user. The display device 106 includes a display including a liquid crystal, an organic electro-luminescence (EL), etc., and an interface circuit outputting image data to the display, and displays the image data on the display.

FIG. 2 is a diagram illustrating a conveyance path inside the medium conveying apparatus.

The conveyance path inside the medium conveying apparatus 100 includes a first medium sensor 111, a regulating guide 112, a cam member 113, a flap 114, a feed roller 115, a separation roller 116, a second medium sensor 117, an ultrasonic sensor 118, a conveyance roller 119, a first facing roller 120, a third medium sensor 121, an imaging device 122, an ejection roller 123, and a second facing roller 124, etc.

Each of the numbers of the feed roller 115, the separation roller 116, the conveyance roller 119, the first facing roller 120, the ejection roller 123, and/or the second facing roller 124 is not limited to one and may be more than one. In that case, a plurality of feed rollers 115, separation rollers 116, conveyance rollers 119, first facing rollers 120, ejection rollers 123, and/or second facing rollers 124 are respectively spaced in the width direction A2 perpendicular to the medium conveying direction.

The top surface of the lower housing 101 forms a lower guide 101a of the conveyance path of a medium, and the bottom surface of the upper housing 102 forms an upper guide 102a of the conveyance path of a medium.

The first medium sensor 111 is located on the upstream side of the feed roller 115 and the separation roller 116. The first medium sensor 111 includes a contact detection sensor and detects whether a medium is placed on the loading tray 103. The first medium sensor 111 generates and outputs a medium signal the signal value of which varies between a state in which a medium is placed on the loading tray 103 and a state in which a medium is not placed. The first medium sensor 111 is not limited to a contact detection sensor and any other sensor that can detect the presence of a medium, such as a light detection sensor, may be used as the first medium sensor 111.

The feed roller 115 is provided in the lower housing 101, sequentially feeds media placed on the loading tray 103 from the lower side. The separation roller 116 is a so-called brake roller or retard roller, is provided in the upper housing 102, is located to face the feed roller 115. The separation roller 113 is provided to be rotatable in a direction opposite to the medium feeding direction, or stoppable. The feed roller 115 may be provided in the upper housing 102, and the separation roller 116 may be provided in the lower housing 101.

The second medium sensor 117 is located on the downstream side of the feed roller 115 and on the upstream side of the conveyance roller 119, and detects a medium conveyed to the position of the sensor. The second medium sensor 117 includes a light emitter and a light receiver that are provided on one side of the medium conveyance path and a light guide, provided at a position facing the light emitter and the light receiver with the medium conveyance path in between. The light emitter is a light emitting diode (LED), etc., and emits light toward the medium conveyance path. The light receiver is a photodiode, etc., and receives light emitted by the light emitter and guided by the light guide. When a medium is present at a position facing the second medium sensor 117, light emitted from the light emitter is blocked by the medium, and therefore 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, the signal value of which varies between a state in which a medium is present at the position of the second medium sensor 117 and a state in which a medium is not present, based on the intensity of light received by the light receiver.

A reflection member such as a mirror may be used in place of the light guide. Further, the light emitter and the light receiver may be provided to face each other with the medium conveyance path in between. Further, the second medium sensor 117 may detect existence of a medium by, for example, a contact detection sensor to pass predetermined current when a medium is in contact or when a medium is not in contact.

The ultrasonic sensor 118 is located on the downstream side of the feed roller 115 and in particular, on the downstream side of the second medium sensor 117 and on the upstream side of the conveyance 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 located close to the conveyance path of a medium to face each other with the conveyance path in between. The ultrasonic transmitter 118a transmits an ultrasonic wave. The ultrasonic receiver 118b receives an ultrasonic wave transmitted by the ultrasonic transmitter 118a and passing through a medium and generates and outputs an ultrasonic signal being an electric signal based on the received ultrasonic wave. When a plurality of media are conveyed in a stacked manner, an ultrasonic wave passing through the media is attenuated by an air layer between the media conveyed in a stacked manner. Accordingly, the medium conveying apparatus 100 can detect multi feed of media, based on the ultrasonic signal.

The conveyance roller 119 and the first facing roller 120 are located on the downstream side of the feed roller 112 in the medium conveying direction A1 to face each other. The conveyance roller 119 is provided in the upper housing 102 and conveys a medium fed by the feed roller 115 and the separation roller 116 to the imaging device 122. The conveyance roller 119 may be provided in the lower housing 101, and the first facing roller 120 may be provided in the upper housing 102.

The third medium sensor 121 is located on the downstream side of the conveyance roller 119 and on the upstream side of the imaging device 122, and detects a medium conveyed to the position of the sensor. The third medium sensor 121 includes a light emitter and a light receiver that are provided on one side of the medium conveyance path and a light guide, provided at a position facing the light emitter and the light receiver with the medium conveyance path in between. The light emitter is an LED, etc., and emits light toward the medium conveyance path. The light receiver is a photodiode, etc., and receives light emitted by the light emitter and guided by the light guide. When a medium is present at a position facing the third medium sensor 121, light emitted from the light emitter is blocked by the medium, and therefore the light receiver does not detect the light emitted from the light emitter. The third medium sensor 121 generates and outputs a third medium signal, the signal value of which varies between a state in which a medium is present at the position of the third medium sensor 121 and a state in which a medium is not present, based on the intensity of light received by the light receiver.

A reflection member such as a mirror may be used in place of the light guide. Further, the light emitter and the light receiver may be provided to face each other with the medium conveyance path in between. Further, the third medium sensor 121 may detect existence of a medium by, for example, a contact detection sensor to pass predetermined current when a medium is in contact or when a medium is not in contact.

The imaging device 122 is an example of an imaging module, is located on the downstream side of the conveyance roller 119 and the first facing roller 120 in the medium conveying direction A1, and images a medium conveyed by the conveyance roller 119 and the first facing roller 120. The imaging device 122 includes a first imaging device 122a and a second imaging device 122b that are located to face each other with the medium conveyance path in between.

The first imaging device 122a includes a line sensor based on a unity-magnification optical system type contact image sensor (CIS) including complementary metal oxide semiconductor- (CMOS-) based imaging elements linearly arranged in a main scanning direction. The first imaging device 122a further includes lenses each forming an image on an imaging element, and an A/D converter amplifying and analog-digital (A/D) converting an electric signal output from the imaging element. The first imaging device 122a generates an input image by imaging the front side of a conveyed medium in accordance with control from a processing circuit described later and outputs the generated image.

The second imaging device 122b includes a line sensor based on a unity-magnification optical system type CIS including CMOS-based imaging elements linearly arranged in the main scanning direction. The second imaging device 122b further includes lenses each forming an image on an imaging element, and an A/D converter amplifying and analog-digital (A/D) converting an electric signal output from the imaging element. The second imaging device 122b generates an input image by imaging the back side of a conveyed medium in accordance with control from the processing circuit described later and outputs the generated image.

Only one of the first imaging device 122a and the second imaging device 122b may be located and only one side of a medium may be read in the medium conveying apparatus 100.

Further, a line sensor based on a unity-magnification optical system type CIS including charge coupled device- (CCD-) based imaging elements may be used in place of the line sensor based on a unity-magnification optical system type CIS including CMOS-based imaging elements. Further, a reduction optical system type line sensor including CMOS-based or CCD-based imaging elements may be used. The image sensors may be located to face each other, or may not be located to face each other.

The ejection roller 123 and the second facing roller 124 are located on the downstream side of the imaging device 122, i.e., on the downstream side of the conveyance roller 119 and the first facing roller 120 in the medium conveying direction A1, to face each other. The ejection roller 123 is provided in the upper housing 102, conveys a medium conveyed by the conveyance roller 119 and the first facing roller 120 toward the further downstream side, and ejects it into the ejection tray 104. The ejection roller 123 may be provided in the lower housing 101, and the second facing roller 124 is provided in the upper housing 102.

A medium placed on the loading tray 103 is conveyed between the lower guide 101a and the upper guide 102a toward the medium conveying direction A1 by the feed roller 115 rotating in a direction of an arrow A4, i.e., the medium feeding direction. The medium conveying apparatus 100 includes a separation mode of separating and feeding a medium and a non-separation mode of feeding a medium without separation as feed modes. The feed mode is set by a user by using the operation device 105 or an information processing apparatus connected to the medium conveying apparatus 100 by communication. When the feed mode is set to the separation mode, the separation roller 116 rotates in a direction of an arrow A5, i.e., a direction opposite to the medium feeding direction or stops. When a plurality of media are placed on the loading tray 103, only a medium in contact with the feed roller 115 of the medium placed on the loading tray 103 is separated by working of the feed roller 115 and the separation roller 116. Consequently, conveyance of a medium other than the separated medium is restricted (prevention of multi feed). On the other hand, when the feed mode is set to the non-separation mode, the separation roller 116 rotates in a direction opposite to the arrow A5, i.e., the medium feeding direction.

A medium is fed between the conveyance roller 119 and the first facing 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 by the conveyance roller 119 and the first facing roller 120 rotating in directions of an arrow A6 and an arrow A7, respectively. The medium read by the imaging device 122 is ejected into the ejection tray 104 by the ejection roller 123 and the second facing roller 124 rotating in directions of an arrow A8 and an arrow A9, respectively.

As illustrated in FIG. 2, the medium conveying apparatus 100 includes a first motor 131, a second motor 132, and a third motor 133 as driving sources of the rollers.

The first motor 131 is provided in the lower housing 101, is connected to the feed roller 115 through a first transmission mechanism 131a, and drives the feed roller 115. The first motor 131 generates a driving force for driving the feed roller 115 in accordance with a control signal from a processing circuit. The first transmission mechanism 131a includes one or a plurality of pulleys, belts, gears, etc., provided between the first motor 131 and a shaft 115abeing the rotation axis of the feed roller 115 and transmits the driving force generated by the first motor 131 to the feed roller 115. The first motor 131 feeds a medium by rotating the feed roller 115. The first motor 131 may be located in the upper housing 102.

The second motor 132 is provided in the upper housing 102 separately from the first motor 131, is connected to the separation roller 116 through a second transmission mechanism 132a, and drives the separation roller 116. The second motor 132 generates a driving force for driving the separation roller 116 in accordance with a control signal from the processing circuit. The second transmission mechanism 132a includes one or a plurality of pulleys, belts, gears, etc., provided between the second motor 132 and a shaft 116a being 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. The second motor 132 separates, feeds, and conveys a medium by rotating the separation roller 116. The second motor 132 may be located in the lower housing 101.

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 conveyance roller 119, the ejection roller 123, and the cam member 113 through a third transmission mechanism 133a and drives the conveyance roller 119, the ejection roller 123, and the cam member 113. The third motor 133 generates a driving force for driving the conveyance roller 119, the ejection roller 123, and the cam member 113 in accordance with a control signal from the processing circuit. The third transmission mechanism 133a includes one or a plurality of pulleys, belts, gears, etc., provided between the third motor 133, and a shaft 119a being the rotation axis of the conveyance roller 119, a shaft 123a being the rotation axis of the ejection roller 123 and the rotation axis 113a of the cam member 113. The third transmission mechanism 133a transmits the driving force generated by the third motor 133 to the conveyance roller 119, the ejection roller 123, and the cam member 113. The third motor 133 conveys and ejects a medium by rotating the conveyance roller 119 and the ejection roller 123. In other words, the conveyance roller 119 and the ejection roller 123 are provided to be driven by the third motor 133. Further, the third motor 133 moves the regulating guide 112 in contact with the cam member 113 by rotating the cam member 113. The third motor 133 may be located in the lower housing 101.

Thus, in the medium conveying apparatus 100, a motor for driving the conveyance roller 119 and the ejection roller 123 and a motor for moving the regulating guide 112 may be common. Consequently, the medium conveying apparatus 100 can reduce the cost and weight of the apparatus by reducing the number of motors.

The first facing roller 120 is a driven roller driven to rotate by the conveyance roller 119, and the second facing roller 124 is a driven roller driven to rotate by the ejection roller 123.

The first facing roller 120 and/or the second facing roller 124 may be provided to be driven by the driving force from the third motor 133. In that case, one or a plurality of gears are further provided between the shaft 119a of the conveyance roller 119 and a shaft 120a being the rotation axis of the first facing roller 120 and/or between the shaft 123a of the ejection roller 123 and a shaft 124a being the rotation axis of the second facing roller 124. The third transmission mechanism 133a further transmits the driving force generated by the third motor 133 to the first facing roller 120 and/or the second facing roller 124.

FIG. 3 is a schematic diagram for illustrating the regulating guide, the cam member, and the flap. FIG. 3 is a schematic diagram of the regulating guide, the cam member, and the flap viewed from the side before medium feeding.

As illustrated in FIG. 3, the regulating guide 112 is a guide for setting a medium (group) M1 placed on the loading tray 103. The regulating guide 112 is located at a position facing the feed roller 115 and the separation roller 116 in the medium conveying direction A1. The regulating guide 112 is rotatably (swingably) supported by the lower housing 101 and, when feeding of the medium M1 is not executed, supports the bottom surface of the medium M1 placed on the loading tray 103. The position where the regulating guide 112 supports the bottom surface of the medium M1 placed on the loading tray 103 as illustrated in FIG. 3 maybe hereinafter referred to as a set position.

The cam member 113 is a moving member for moving the regulating guide 112. The cam member 113 is located on the downstream side of the regulating guide 112 in the medium conveying direction A1. The cam member 113 is provided to be rotatable (swingable) by the third motor 133. The cam member 113 is supported by the lower housing 101 to be rotatable according to the driving force from the third motor 133 and, when medium feeding is not executed, comes into contact with the downstream edge of the regulating guide 112 and holds the regulating guide 112 at the set position.

The flap 114 is a stopper for preventing the medium M1 from entering a nip part of the feed roller 115 and the separation roller 116 before medium feeding. The flap 114 is located at a position facing the regulating guide 112 in the medium conveying direction A1. The flap 114 is swingably provided in the upper housing 102 and, when feeding of the medium M1 is not executed, the flap 114 is engaged with the regulating guide 112 located at the set position and prevents entry of the medium M1 into the nip part of the feed roller 115 and the separation roller 116.

In other words, the regulating guide 112 at the set position regulates contact of the medium M1 with the feed roller 115 and the separation roller 116. The set position is an example of a first position.

FIG. 4 is a schematic diagram for illustrating operation of the regulating guide, the cam member, and the flap. FIG. 4 is a schematic diagram of the regulating guide, the cam member, and the flap viewed from the side at medium feeding.

As illustrated in FIG. 4, when feeding of the medium M1 is executed, the cam member 113 swings (rotates) downward (in a direction of an arrow A11) according to the driving force from the third motor 133 and separates from the downstream edge of the regulating guide 112. By the downstream edge of the regulating guide separating from the cam member 113 and not being held by the cam member 113, the regulating guide 112 swings below a medium conveyance surface (in a direction of an arrow A12) and separates from the bottom surface of the medium M1 placed on the loading tray 103. The position where the regulating guide 112 is separated from the bottom surface of the medium M1 placed on the loading tray 103 as illustrated in FIG. 4 maybe hereinafter referred to as a release position. By the regulating guide 112 being located at the release position, the engagement between the flap 114 and the regulating guide 112 is released. Consequently, the flap 114 is pushed by the front edge of the medium M1 placed on the loading tray 103 and swings to the downstream side (in a direction of an arrow A13), and the medium M1 can enter the nip part of the feed roller 115 and the separation roller 116. Thus, when the regulating guide 112 is located at the release position, the flap 114 allows entry of the medium M1 into the nip part of the feed roller 115 and the separation roller 116.

In other words, the regulating guide 112 at the release position does not regulate contact of the medium M1 with the feed roller 115 and the separation roller 116. The release position is an example of a second position. The regulating guide 112 is provided to be movable between the set position and the release position. The regulating guide 112 is provided to move by rotation of the cam member 113.

As illustrated in FIG. 3 and FIG. 4, the feed roller 115 is provided with an outer peripheral surface 115b, a one-way clutch 115c, etc. The one-way clutch 115c is located on the shaft 115a being the rotation axis of the feed roller 115. The one-way clutch 115c prevents (the outer peripheral surface 115b of) the feed roller 115 from rotating in a direction opposite to the medium feeding direction A4 relative to the shaft 115a. Consequently, the feed roller 115 is prevented from rotating in the direction opposite to the medium feeding direction A4 due to being dragged by the separation roller 116 rotating in the direction A5 opposite to the medium feeding direction.

The conveyance roller 119 conveys a medium at a conveyance speed greater than the feeding speed of the feed roller 115. Accordingly, when a medium arrives at the position of the conveyance roller 119, the medium is pulled by the conveyance roller 119 while being clamped by the feed roller 115 and the separation roller 116. At this time, the outer peripheral surface 115b of the feed roller 115 rotates according to the clamped medium by the working of the one-way clutch 115c and does not hamper conveyance of the medium. The conveyance roller 119 may convey a medium at a conveyance speed being the same as the feeding speed of the feed roller 115.

The separation roller 116 is provided with an outer peripheral surface 116b, a torque limiter 116c, etc. The torque limiter 116c is located on the shaft 116a being the rotation axis of the separation roller 116. The torque limiter 116c defines a maximum torque exerted on the separation roller 116. The limit value of the torque limiter 116c is set to a value at which a turning force through the torque limiter 116c is cut off when there is one medium and the turning force is transmitted through the torque limiter 116c when there are a plurality of media. Consequently, when only one medium is conveyed, the separation roller 116 is driven by the feed roller 115 instead of rotating according to the driving force from the second motor 132. On the other hand, when a plurality of media are conveyed, the separation roller 116 rotates in the direction A5 opposite to the medium feeding direction and prevents occurrence of multi feed by separating a medium in contact with the feed roller 115 from the remaining media. At this time, the outer peripheral surface 116b of the separation roller 116 may apply a force in the direction A5 opposite to the medium feeding direction to the medium by stopping instead of rotating in the direction A5 opposite to the medium feeding direction.

FIG. 5 is a schematic diagram for illustrating the holding part.

As illustrated in FIG. 5, a holding part 134 is provided in the lower housing 101. The holding part 134 holds substances adhered to a conveyed medium, such as paper dust or dirt, or substances adhered to the feed roller 115 or the separation roller 116 from a conveyed medium.

The lower guide 101a being a medium guide surface in the lower housing 101 includes an opening 101b for locating the feed roller 115. The holding part 134 is located below the feed roller 115 to face the opening 101b and holds substances falling from a conveyed medium, the feed roller 115, or the separation roller 116, and substances entering from a gap between the feed roller 115 and the opening 101b. Further, the holding part 134 is provided to be attachable to and detachable from the lower housing 101, i.e., the medium conveying apparatus 100. The holding part 134 allows the medium conveying apparatus 100 to suitably collect paper dust or dirt and suppress accumulation of paper dust or dirt in the medium conveyance path.

FIG. 6 is a block diagram illustrating a schematic configuration of an example of a medium conveying apparatus.

In addition to the configuration described above, the medium conveying apparatus 100 further includes an interface device 135, a storage device 140, a processing circuit 150, etc.

For example, the interface device 135 includes an interface circuit conforming to a serial bus such as USB and transmits and receives an input image and various types of information by being electrically connected to an unillustrated information processing apparatus (such as a personal computer or a mobile information terminal). A communication device including an antenna transmitting and receiving wireless signals and a wireless communication interface circuit for transmitting and receiving signals through a wireless communication line in accordance with a predetermined communication protocol may be used in place of the interface device 135. For example, the predetermined communication protocol is a wireless local area network (LAN). The communication device may include a wired communication interface circuit for transmitting and receiving signals through a wired communication line in accordance with a communication protocol such as a wired LAN.

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, a portable storage device such as a flexible disk or an optical disk, etc. Further, a computer program, a database, a table, etc., that are used for various types of processing in the medium conveying apparatus 100 are stored in the storage device 140. The computer programs may be installed on the storage device 140 from a computer-readable, non-transitory portable storage medium by using a well-known set-up program, etc. The portable storage medium is, for example, a compact disc read-only memory (CD-ROM) or a digital versatile disc read-only memory (DVD-ROM).

The processing circuit 150 operates in accordance with a program previously stored in the storage device 140. For example, the processing circuit is a central processing unit (CPU). Examples of the processing circuit 150 that may also be used include a digital signal processor (DSP), a large scale integration (LSI), an application specific integrated circuit (ASIC), and a field-programmable gate array (FPGA).

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, etc., and controls the components. The processing circuit 150 performs drive control of each motor, imaging control of the imaging device 122, etc., based on each medium signal received from each medium sensor.

The processing circuit 150 acquires an input image from the imaging device 122 and transmits the acquired image to the information processing apparatus through the interface device 135. Further, the processing circuit 150 determines whether multi feed of media has occurred, based on an ultrasonic signal received from the ultrasonic sensor 118, and when multi feed of media has occurred, controls each motor to return the media to the loading tray 103.

FIG. 7 is a diagram illustrating a schematic configuration of an example of a storage device and a processing circuit.

As illustrated in FIG. 7, a control program 141, a determination program 142, etc., are stored in the storage device 140. Each program is a functional module implemented by software operating on the processor. The processing circuit 150 reads each program stored in the storage device 140 and operates in accordance with the read program. Consequently, the processing circuit 150 functions as a control module 151, and a determination module 152.

FIG. 8 and FIG. 9 are flowcharts illustrating an operation example of medium reading processing in a medium conveying apparatus.

The operation example of the medium reading process in the medium conveying apparatus 100 will be described below referring to the flowchart illustrated in FIG. 8 and FIG. 9.

The operation flow described below is executed mainly by the processing circuit 150 in accordance with a program previously stored in the storage device 140 in cooperation with the components in the medium conveying apparatus 100.

First, the control module 151 waits until an instruction to read a medium is input by a user by using the operation device 105 or the information processing apparatus and an operation signal providing an instruction to read a medium is received from the operation device 105 or the interface device 132 (step S101).

Next, the control module 151 acquires the medium signal from the first medium sensor 111 and determines whether a medium exist on the loading tray 103, based on the acquired medium signal (step S102). When a medium does not exist on the loading tray 103, the control module 151 ends the series of steps.

On the other hand, when a medium exists on the loading tray 103, the control module 151 first drives the third motor 133 (step S103). By driving the third motor 133, the control module 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, i.e., from the set position to the release position. Further, by driving the third motor 133, the control module 151 rotates the conveyance roller 119, the first facing roller 120, the ejection roller 123, and/or the second facing roller 124 in the directions of the arrows A6, A7, A8, and/or A9 in FIG. 2, respectively.

Next, the control module 151 rotates the separation roller 116 in a direction opposite to the medium feeding direction (in the direction of the arrow A5 in FIG. 2) by driving the second motor 132 (step S104).

Next, the control module 151 rotates the feed roller 115 in the medium feeding direction (in the direction of the arrow A4 in FIG. 2) to feed the medium by driving the first motor 131 (step S105).

FIG. 10 is a graph for illustrating changes in the speeds of the feed roller, the separation roller, and the conveyance roller.

In FIG. 10, a graph G11 illustrates changes in the speed of the feed roller 115, a graph G12 illustrates changes in the speed of the separation roller 116, and a graph G13 illustrates changes in the speed of the conveyance roller 119. Since the speeds of the first facing roller 120, the ejection roller 123, and the second facing roller 124 change similarly to the speed of the conveyance roller 119, changes in the speed of the conveyance roller 119 will be described below as a representative. The horizontal axis of each of the graphs G11 to G13 indicates time, and the vertical axis of each of the graphs G11 to G13 indicates speed.

On the other hand, a graph G14 illustrates changes in the signal value of the second medium sensor 117, and a graph G15 illustrates changes in the signal value of the third medium sensor 121. The horizontal axis of each of the graphs G14 and G15 indicates time, and the vertical axis indicates the signal value of each of the graphs G14 and G15. According to the present embodiment, when a medium does not exist at the position of each sensor, the signal value of a related signal takes on L, and when a medium exists at the position of each sensor, the signal value of a related signal takes on H.

In FIG. 10, a time T1 denotes the time when medium feeding is started. As described above, the control module 151 starts driving the third motor 133, the second motor 132, and the first motor 131 in this order, and therefore, the conveyance roller 119, the separation roller 116, and the feed roller 115 sequentially start rotation at times T1, T2, and T3, respectively. The speed (the surface moving speed) V2 of the separation roller 116 is set to a speed less than the speed (surface moving speed) V1 of the feed roller 115. The speed (the surface moving speed)

V3 of the conveyance roller 119 is set to a speed greater than the speed (the surface moving speed) V1 of the feed roller 115.

The control module 151 starts driving the third motor 133, the second motor 132, and the first motor 131 in this order. Therefore, when the regulating guide 112 moves from the set position and regulation of a medium by the flap 114 is released, i.e., when the front edge of a medium placed on the loading tray 103 comes into contact with the separation roller 116 and the feed roller 115, the feed roller 115 and the separation roller 116 are at a standstill. Then, the separation roller 116 starts rotation before the feed roller 115 starts rotation. Accordingly, as illustrated in FIG. 4, the medium group M1 placed on the loading tray 103 comes into contact with the separation roller 116 before entering the nip part of the feed roller 115 and the separation roller 116. The front edge of the medium group M1 is arranged such that a medium closer to the top is placed further on the upstream side by the separation roller 116 rotating in the direction opposite to the medium feeding direction. Consequently, a plurality of media entering the nip part of the feed roller 115 and the separation roller 116 together when rotation of the feed roller 115 starts is suppressed, and occurrence of multi feed of media is suppressed.

By the separation roller 116 starting rotation before the feed roller 115 starts rotation, the separation roller 116 being driven by the feed roller 115 before the start of rotation is suppressed, and the separation roller 116 can satisfactorily separate media.

The control module 151 may execute the processing in step S104 before the processing in step S103 and operate the third motor 133 after operating the second motor 132 when feeding of a medium is started. In that case, the separation roller 116 rotates and the feed roller 115 is at a standstill when the regulating guide 112 moves from the set position and the front edge of the medium comes into contact with the separation roller 116 and the feed roller 115. Accordingly, in that case, the medium conveying apparatus 100 also controls the first motor 131, the second motor 132, and the third motor 133 such that the feed roller 115 rotates after the separation roller 116 in a rotating state contacts the medium. The front edge of the medium group M1 is arranged such that a medium closer to the top is placed further on the upstream side by the separation roller 116 rotating in the direction opposite to the medium feeding direction. Consequently, occurrence of multi feed of media due to a plurality of media entering the nip part of the feed roller 115 and the separation roller 116 together when rotation of the feed roller 115 starts is suppressed.

Thus, the control module 151 controls the first motor 131, the second motor 132, and the third motor 133, i.e., the feed roller 115, the separation roller 116, and the regulating guide 112 such that, when feeding of a medium is started, the feed roller 115 rotates, i.e., feeds the medium, after the separation roller 116 in a rotating state comes in contact with the medium. In particular, when feeding of a medium is started, the control module 151 operates the first motor 131 after operating the second motor 132 and the third motor 133. Consequently, the control module 151 can suppress occurrence of multi feed of media when feeding of the media is started.

As described above, the regulating guide 112 is provided to move by rotation of the cam member 113, and the regulating guide 112 and the flap 114 regulate contact of a medium with the feed roller 115 and the separation roller 116 by engaging each other. Accordingly, it takes a certain time after 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 module 151 can shorten the time required for feeding of a medium by starting movement of the regulating guide 112 and the flap 114 by driving the third motor 133 before starting rotation of the feed roller 115 by driving the first motor 131.

The control module 151 may wait for 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 required for the front edge of a medium regulated by the flap 114 to come into contact with the separation roller 116 rotating in the direction opposite to the medium feeding direction after the third motor 133 is driven. Consequently, the control module 151 can reliably apply a separating force exerted by the separation roller 116 to a medium group before a feeding force exerted by the feed roller 115 is applied and medium conveying apparatus can reliably suppress occurrence of multi feed of media.

As described above, the shaft 116a of the separation roller 116 is provided with the torque limiter 116c. Depending on the placement position of the torque limiter 116c, a gap (a backlash component) to which a driving force is not transmitted may exist between the shaft 116a and (the outer peripheral surface 116b of) the separation roller 116. Therefore, depending on the placement position of the torque limiter 116c, it may take a certain time until the driving force from the second motor 132 is transmitted to the separation roller 116. By starting rotation of the separation roller 116 by driving the second motor 132 before starting rotation of the feed roller 115 by driving the first motor 131, the control module 151 can eliminate the gap (backlash component) between the shaft 116a and the separation roller 116. Consequently, the control module 151 can reliably apply a separating force exerted by the separation roller 116 to a medium group before a feeding force exerted by the feed roller 115 is applied and can suppress occurrence of multi feed of media.

The control module 151 may wait for a second predetermined time after driving the second motor 132 in step S104 before driving the first motor 131 in step S105. The second predetermined time is set to the time required for the separation roller 116 to reliably rotate after the second motor 132 is driven. Consequently, the control module 151 can reliably suppress occurrence of multi feed of media.

Next, the control module 151 waits until the front edge of the conveyed medium passes the position of the second medium sensor 117 (step S106). The control module 151 periodically acquires the second medium signal from the second medium sensor 117, and determines that the front edge of the medium has passed the position of the second medium sensor 117 when the signal value of the second medium signal changes from a value indicating that a medium does not exist to a value indicating that a medium exists.

Next, the control module 151 controls the second motor 132 to stop the separation roller 116 (step S107).

In FIG. 10, a time T4 denotes the time when the signal value of the second medium signal changes from L to H, i.e., when the front edge of the medium has passed the position of the second medium sensor 117. As illustrated in FIG. 10, rotation of the separation roller 116 is stopped when the front edge of the medium passes the position of the second medium sensor 117. When passing the position of the second medium sensor 117, the front edge of the medium has already passed the nip part of the feed roller 115 and the separation roller 116, and separation of media is completed. Therefore, by the control module 151 stopping the separation roller 116, the medium conveying apparatus 100 can reduce the amount of power consumption and the apparatus temperature while suitably separating media.

Next, the control module 151 waits until the front edge of the conveyed medium passes the position of the conveyance roller 119 (step S108). The control module 151 periodically acquires the third medium signal from the third medium sensor 121, and determines that the front edge of the medium has passed the position of the third medium sensor 121 when the signal value of the third medium signal changes from a value indicating that a medium does not exist to a value indicating that a medium exists. The control module 151 determines that the front edge of the medium has passed the position of the conveyance roller 119 when the front edge of the medium passes the position of the third medium sensor 121.

Next, the control module 151 controls the first motor 131 to stop the feed roller 115 (step S108).

In FIG. 10, a time T5 denotes the time when the signal value of the third medium signal changes from L to H, i.e., when the front edge of the medium has passed the position of the third medium sensor 121. As illustrated in FIG. 10, after the front edge of the medium passes the position of the third medium sensor 121, the control module 151 stops the feed roller 115. Consequently, from this point, the medium is conveyed by the conveyance roller 119, and the feed roller 115 is rotated by the medium being conveyed. By the control module 151 stopping the feed roller 115, the medium conveying apparatus 100 can suppress occurrence of jamming of the medium due to the medium being pushed by the feed roller 115 and being bent between the feed roller 115 and the conveyance roller 119.

Next, the control module 151 causes the imaging device 122 to start imaging of the medium (step S110).

Next, the control module 151 waits until the rear edge of the conveyed medium passes the position of the second medium sensor 117 (step S111). The control module 151 periodically acquires the second medium signal from the second medium sensor 117, and determines that the rear edge of the medium has passed the position of the second medium sensor 117 when the signal value of the second medium signal changes from a value indicating that a medium exists to a value indicating that a medium does not exist.

Next, the control module 151 determines whether a medium remains on the loading tray 103, based on the medium signal received from the first medium sensor 111 (step S112).

When a medium remains on the loading tray 103, the control module 151 controls the second motor 132 to re-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 S113).

Next, the control module 151 controls the first motor 131 to re-rotate the feed roller 115 in the medium feeding direction (in the direction of the arrow A4 in FIG. 2) to feed a succeeding medium (step S114).

In FIG. 10, a time T6 denotes the time when the signal value of the second medium signal changes from H to L, i.e., when the rear edge of the medium has passed the position of the second medium sensor 117. As described above, the control module 151 starts driving of the second motor 132 and the first motor 131 in this order, and therefore, the separation roller 116 and the feed roller 115 sequentially start rotation at times T6 and T7, respectively.

Consequently, the control module 151 can apply a separating force exerted by the separation roller 116 on the medium group remaining on the loading tray 103 before a feeding force exerted by the feed roller 115 is applied. Accordingly, before entering the nip part of the feed roller 115 and the separation roller 116, the front edge of the medium group remaining on the loading tray 103 is arranged such that a medium closer to the top is placed further on the upstream side by the separation roller 116 rotating in the direction opposite to the medium feeding direction. Therefore, occurrence of multi feed of media due to a plurality of media entering the nip part of the feed roller 115 and the separation roller 116 together when rotation of the feed roller 115 starts is suppressed.

Thus, when feeding of a second or subsequent medium out of media set on the regulating guide 112 is started, the control module 151 controls the first motor 131 and the second motor 132 such that the feed roller 115 rotates after the separation roller 116 rotates. Consequently, the control module 151 can suppress occurrence of multi feed of media when feeding of a second or subsequent medium is started.

Next, the control module 151 waits until the rear edge of the preceding medium passes an imaging position of the imaging device 122 (step S115). The control module 151 periodically acquires the third medium signal from the third medium sensor 121 and determines that the rear edge of the preceding medium has passed the position of the third medium sensor 121 when the signal value of the third medium signal changes from a value indicating that a medium exists to a value indicating that a medium does not exist. The control module 151 determines that the rear edge of the preceding medium has passed the imaging position when a third predetermined time elapses after the rear edge of the preceding medium passes the position of the third medium sensor 121. The third predetermined time is set to a value acquired by adding a margin to the time required for a medium to move from the position of the third medium sensor 121 to the imaging position.

Next, the control module 151 acquires an input image from the imaging device 122 and outputs the acquired input image by transmitting the image to the information processing apparatus through the interface device 135 (step S116).

Next, the control module 151 returns the processing to step S106 and repeats the processing in and after step S106 on a succeeding medium. In this case, the control module 151 waits until the front edge of the succeeding medium passes the position of the second medium sensor 117 (a time T8 in FIG. 10) in step S106 and controls the second motor 132 to stop the separation roller 116 in step S107. Furthermore, the control module 151 waits until the front edge of the succeeding medium passes the position of the conveyance roller 119 (a time T9 in FIG. 10) in step S108 and controls the first motor 131 to stop the feed roller 115 in step S109.

On the other hand, when a medium does not remain on the loading tray 103 in step S112, the control module 151 waits until the rear edge of the conveyed medium passes the imaging position of the imaging device 122, similarly to the processing in step S115 (step S117).

Next, the control module 151 waits until the rear edge of the conveyed medium passes the position of the ejection roller 123 (step S119). The control module 151 determines that the rear edge of the medium has passed the position of the ejection roller 123 when a fourth predetermined time elapses after the rear edge of the medium passes the position of the third medium sensor 121. The fourth predetermined time is set to a value acquired by adding a margin to the time required for a medium to move from the position of the third medium sensor 121 to the position of the ejection roller 123.

Next, the control module 151 controls the third motor 133 to stop the conveyance roller 119, the first facing roller 120, the ejection roller 123, and/or the second facing roller 124 (step S120).

Next, the control module 151 controls (counterrotates) the third motor 133 to move the regulating guide 112 in a direction opposite to the arrow A12 in FIG. 3, i.e., from the release position to the set position by rotating the cam member 113 in a direction opposite to the arrow A11 in FIG. 3 (step S121). Consequently, the regulating guide 112 is located at the set position, and the flap 114 is engaged with the regulating guide 112 located at the set position and is located at a position where the medium is prevented from entering the nip part of the feed roller 115 and the separation roller 116 (the position illustrated in FIG. 3). At this time, the conveyance roller 119, the first facing roller 120, the ejection roller 123, and/or the second facing roller 124 rotate in directions opposite to the arrows A6, A7, A8, and A9 in FIG. 2, respectively; however, since no medium exists in the medium conveyance path, no issue occurs.

Next, the control module 151 controls the third motor 133 to stop the cam member 113 (step S122).

Next, the control module 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 module 151 controls the first motor 131 or the second motor 132 to rotate either one or both of the feed roller 115 and the separation roller 116 in the medium feeding direction. By the control module 151 rotating either one of the feed roller 115 and the separation roller 116, the other roller can be driven to rotate.

In other words, when not feeding a medium, the control module 151 controls the first motor 131 or the second motor 132 to rotate the feed roller 115 or the separation roller 116 while the regulating guide 112 is located at the set position. The control module 151 rotates the feed roller 115 or the separation roller 116 to move substances adhered to the feed roller 115 or the separation roller 116. By rotating the feed roller 115 and the separation roller 116, substances adhered from a fed medium to the feed roller 115 or the separation roller 116 falls from the feed roller 115 or the separation roller 116 and is held by the holding part 134. Further, by rotating the feed roller 115 and the separation roller 116, substances adhered to each roller or substances gathered around each roller area are spread. A contact area between the medium and a rubber part of each roller is secured, and the medium conveying apparatus 100 can suppress decline in a medium feeding force and a medium separating force.

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

The processing in steps S103, S104, and S105 may be executed in any order. The processing in steps S113 and S114 may be executed in any order. The processing in steps S123 and S124 may be executed at any timing when a medium is not fed. Alternatively, the processing in steps S123 and S124 may be omitted.

FIG. 11 is a flowchart illustrating an operation example of multi feed determination process in the medium conveying apparatus.

An operation example of the multi feed determination process in the medium conveying apparatus 100 will be described below referring to the flowchart illustrated in FIG. 11. The operation flow described below is executed mainly by the processing circuit 150 in accordance with a program prestored in the storage device 140 in cooperation with each component in the medium conveying apparatus 100. The operation flow illustrated in FIG. 11 is periodically executed during medium conveyance.

First, the determination module 152 acquires an ultrasonic signal from the ultrasonic sensor 118 (step S201).

Next, the determination module 152 determines whether multi feed of media has occurred, based on the acquired ultrasonic signal (step S202). The determination module 152 determines that multi feed of media has not occurred when the signal value of the ultrasonic signal is greater than or equal to a multi feed threshold value and determines that multi feed of media has occurred when the signal value of the ultrasonic signal is less than the multi feed threshold value. The multi feed threshold value is set to a value between a signal value of the ultrasonic signal when a sheet of paper is conveyed and a signal value of the ultrasonic signal when multi feed of papers occurs. When determining that multi feed of media has not occurred, the determination module 152 returns the processing to step S201 and repeats the processing in steps S201 and S202.

On the other hand, when the determination module 152 determines that multi feed of media has occurred, the control module 151 temporarily stops the medium reading process (step S203).

Next, the control module 151 controls the first motor 131 and the second motor 132 to stop the feed roller 115 and the separation roller 116 (step S204). The determination module 152 detects occurrence of multi feed of media when the front edge of multi-fed media passes the position of the ultrasonic sensor 118. At this time, the front edge of the media has not arrived at the position of the conveyance roller 119. Therefore, the control module 151 controls the third motor 133 to continuously rotate the conveyance roller 119, the first facing roller 120, the ejection roller 123, and/or the second facing roller 124. Consequently, the control module 151 can continue conveyance of a medium fed before the multi-fed media.

Next, the control module 151 controls the second motor 132 to re-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 S205).

Next, the control module 151 returns the multi-fed media to the loading tray 103 by controlling (counterrotating) the first motor 131 to rotate the feed roller 115 in a direction opposite to the medium feeding direction (in a direction opposite to the arrow A4 in FIG. 2) (step S206). The control module 151 controls the first motor 131 and the second motor 132 such that the circumferential speed of the shaft 115a being the rotation axis of the feed roller 115 is greater than the circumferential speed of the outer peripheral surface 115b of the feed roller 115 driven by the separation roller 116.

Thus, when the determination module 152 determines that multi feed of media has occurred, the control module 151 controls the first motor 131 and the second motor 132 to return the media to the loading tray 103. When returning the media to the loading tray 103, the control module 151 controls the first motor 131 and the second motor 132 to rotate the feed roller 115 after rotating the separation roller 116. When returning the media to the loading tray 103, the control module 151 controls the first motor 131 and the second motor 132 such that the circumferential speed of the shaft 115a being the rotation axis of the feed roller 115 is greater than the circumferential speed of the outer peripheral surface 115b of the feed roller 115 driven by the separation roller 116.

FIG. 12 is a schematic diagram for illustrating an operation of returning multi-fed media M2 to the loading tray. FIG. 12 is a schematic diagram of the feed roller and the separation roller viewed from the side when multi feed occurs.

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 allowing transmission of a turning force through the torque limiter 116c when there are a plurality of media. When the shaft 115a being the rotation axis of the feed roller 115 is rotated in a direction A21 opposite to the medium feeding direction, the outer peripheral surface 115b of the feed roller 115 does not rotate according to the driving force from the first motor 131 due to the working of the one-way clutch 115c. The outer peripheral surface 115b of the feed roller 115 is driven to rotate by the separation roller 116 in a direction A22 opposite to the medium feeding direction.

The shaft 115a of the feed roller 115 is provided to rotate at a circumferential speed greater than the circumferential speed of the outer peripheral surface 115b of the feed roller 115 driven to rotate by the separation roller 116. Consequently, the outer peripheral surface 115b of the feed roller 115 rotates according to rotation of the outer peripheral surface 116b of the separation roller 116 without being hampered by the one-way clutch 115c. Thus, the feed roller 115 is provided to be driven to rotate by the separation roller 116 in the direction A22 opposite to the medium feeding direction. The separation roller 116 rotates in the direction A5 opposite to the medium feeding direction without receiving a load by the feed roller 115.

Accordingly, even when a plurality of media M2 are multi fed between the separation roller 116 and the feed roller 115, the medium conveying apparatus 100 can return all of the plurality of media M2 to the loading tray 103 by counterrotating the first motor 131.

As described above, the shaft 116a of the separation roller 116 is provided with the torque limiter 116c, and, depending on the placement position of the torque limiter 116c, a backlash component to which a driving force is not transmitted may exist between the shaft 116aand the separation roller 116. Therefore, assuming that 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 rotation in a state of the separation roller 116 not being locked. In this case, the media are not sufficiently fixed by the separation roller 116 and are in an unstable state; and a wrinkle may occur in a medium in contact with the feed roller 115 (a medium positioned at the bottom) when rotation of the shaft 115a of the feed roller 115 starts. Furthermore, the separation roller 116 starts rotation in a state of the outer peripheral surface 115b of the feed roller 115 not being locked. The media are not sufficiently fixed by the outer peripheral surface 115b of the feed roller 115 and are in an unstable state; and a wrinkle may occur in a medium in contact with the separation roller 116 (a medium positioned at the top) when rotation of the separation roller 116 starts.

The medium conveying apparatus 100 rotates the shaft 115a of the feed roller 115 after rotating the separation roller 116. Consequently, when rotation of the separation roller 116 starts, the outer peripheral surface 115b of the feed roller 115 is supported by the shaft 115a of the feed roller 115, and the media are in a stabilized state by the feed roller 115. Accordingly, the medium conveying apparatus 100 can suppress occurrence of a wrinkle in a medium in contact with the separation roller 116 (a medium positioned at the top). Further, a backlash component does not exist between the separation roller 116 and the shaft 116a when rotation of the shaft 115a of the feed roller 115 starts, and the media are in a stabilized state by the separation roller 116. Accordingly, the medium conveying apparatus 100 can suppress occurrence of a wrinkle in a medium in contact with the feed roller 115 (a medium positioned at the bottom).

The control module 151 may wait for a fifth predetermined time after re-rotating the separation roller 116 in step S205 before counterrotating the feed roller 115 in step S206. The fifth predetermined time is set to the time required for the separation roller 116 to rotate by a backlash component between the separation roller 116 and the shaft 116a. Consequently, the control module 151 can start rotation of the shaft 115a of the feed roller 115 after the backlash component between the separation roller 116 and the shaft 116a reliably disappears and can more reliably suppress occurrence of a wrinkle in a medium.

Next, the control module 151 waits until the media are returned to the loading tray 103 (step S207). The control module 151 periodically acquires the second medium signal from the second medium sensor 117 and determines that the downstream edge of the media traveling in the opposite 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 that a medium exists to a value indicating that a medium does not exist. The control module 151 determines that the media have returned to the loading tray 103 when a sixth predetermined time elapses after the downstream edge of the media passes the position of the second medium sensor 117. The sixth predetermined time is set to a value acquired by adding a margin to the time required for media traveling in the opposite direction to move from the position of the second medium sensor 117 to the upstream edge of the nip part of the feed roller 115 and the separation roller 116.

Next, the control module 151 controls the first motor 131 and the second motor 132 to stop the feed roller 115 and the separation roller 116 (step S208).

Next, the control module 151 resumes the medium reading process (step S209).

Since the conveyance roller 119, the first facing roller 120, the ejection roller 123, and/or the second facing roller 124 are already rotating, the control module 151 resumes the medium reading process from the processing in step S104 in FIG. 8. Further, the control module 151 returns the processing to step S201 and repeats the processing in steps S201 to S209.

The feed roller 115 may not include the one-way clutch 115c and be provided such that the outer peripheral surface 115b rotates according to rotation of the shaft 115a. In that case as well, the control module 151 controls the second motor 132 to re-rotate the separation roller 116 in the direction opposite to the medium feeding direction in step S205 and controls the first motor 131 to rotate the feed roller 115 in the direction opposite to the medium feeding direction in step S206. In other words, when returning the media to the loading tray 103, the control module 151 controls the first motor 131 and the second motor 132 to rotate the feed roller 115 after rotating the separation roller 116. When returning the media to the loading tray 103, the control module 151 controls the first motor 131 and the second motor 132 such that the moving speed of the outer peripheral surface 115b of the feed roller 115 is greater than the moving speed of the outer peripheral surface 116b of the separation roller 116.

In this case as well, when the plurality of media M2 are multi fed between the separation roller 116 and the feed roller 115, the medium conveying apparatus 100 can return all of the plurality of media M2 to the loading tray 103 by counterrotating the first motor 131.

When multi feed of media occurs, multi-fed media exist on a medium positioned at the bottom, and gravity of the multi-fed media 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, a downward force exerted by the gravity of the multi-fed media and a force toward the upstream side exerted by the feed roller 115 are applied to the medium positioned at the bottom.

Therefore, a medium twisting force is applied to the medium positioned at the bottom, and a wrinkle may occur.

The medium conveying apparatus 100 rotates the feed roller 115 after rotating the separation roller 116. No medium exists on a medium being in contact with the separation roller 116 and being positioned at the top. Therefore, when the separation roller 116 is rotated before the feed roller 115 is rotated, only a force toward the upstream side exerted by the separation roller 116 is applied to the medium in contact with the separation roller 116, and therefore, the possibility of occurrence of a wrinkle is low. Accordingly, the medium conveying apparatus 100 can suppress occurrence of a wrinkle in a medium by rotating the feed roller 115 after rotating the separation roller 116.

The control module 151 sets the moving speed of the outer peripheral surface 115b of the feed roller 115 to a speed greater than the moving speed of the outer peripheral surface 116b of the separation roller 116. Consequently, the control module 151 can cause the medium being in contact with the feed roller 115 and being positioned at the bottom to catch up with the medium being in contact with the separation roller 116 and being positioned at the top. Accordingly, the control module 151 can synchronize timings for returning the respective multi-fed media to the loading tray 103 and therefore enables early completion of recovery of the media.

The control module 151 may control the first motor 131 and the second motor 132 such that the rotation amount of the separation roller 116 (the moving amount of the outer peripheral surface 116b) is greater than the rotation amount of the feed roller 115 (the moving amount of the outer peripheral surface 115b). By increasing the rotation amount of the separation roller 116, the control module 151 can more reliably return an upper medium fed with a medium being a feed target to the loading tray 103. Further, by decreasing the rotation amount of the feed roller 115, the control module 151 can suppress occurrence of a wrinkle in a lower medium due to excessively returning the medium.

The medium conveying apparatus 100 may not execute the multi feed determination process.

As described in detail above, 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 apparatus 100. When feeding of a medium starts, the medium conveying apparatus 100 controls the first motor 131, the second motor 132, and the third motor 133 such that the feed roller 115 rotates after the separation roller 116 in a rotating state contacts the medium. Consequently, the medium conveying apparatus 100 can satisfactorily arrange the front edge of a medium group placed on the loading tray 103 by the separation roller 116 and can more satisfactorily separate media.

The first motor 131 for driving the feed roller 115 and the second motor 132 for driving the separation roller 116 are separately provided in the medium conveying apparatus 100. When returning media to the loading tray 103 at occurrence of multi feed, the medium conveying apparatus 100 controls the first motor 131 and the second motor 132 to rotate the shaft 115a of the feed roller 115 after rotating the separation roller 116. Consequently, the medium conveying apparatus 100 can stably return multi-fed media to the loading tray 103 and can more suitably restore media when multi feed of the media occurs.

Further, the medium conveying apparatus 100 can stably separate media and can stably return multi-fed media to the loading tray 103 regardless of the number of media conveyed together or the type of conveyed medium. Further, when returning multi-fed media to the loading tray 103, the medium conveying apparatus 100 can suppress occurrence of a jam of a medium.

FIG. 13 is a diagram for illustrating a conveyance path inside a medium conveying apparatus according to another embodiment.

The medium conveying apparatus 200 includes the components included in the medium conveying apparatus 100. However, the medium conveying apparatus 200 includes a second motor 232, a third motor 233, a second transmission mechanism 232a, and a third transmission mechanism 233a in place of the second motor 132, the third motor 133, the second transmission mechanism 132a, and the third transmission mechanism 133a.

The second motor 232 and the second transmission mechanism 232a have structures similar to those of 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 through 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 in accordance with a control signal from the processing circuit 150. The second transmission mechanism 232a includes one or a plurality of pulleys, belts, gears, etc., provided between the second motor 232, and the shaft 116a being the rotation axis of the separation roller 116 and the rotation axis 113a of the cam member 113. In particular, one or a plurality of gears for varying the rotation direction of the separation roller 116 and the rotation direction of the cam member 113 are provided between the shaft 116a of the separation roller 116 and the rotation axis 113a 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. Consequently, the second motor 232 causes the separation roller 116 to separate, feed, and convey a medium by rotating the separation roller 116. Further, the second motor 232 moves the regulating guide 112 in contact with the cam member 113 by rotating the cam member 113. In other words, in the medium conveying apparatus 200, the cam member 113 is provided to be rotatable by the second motor 232, and the regulating guide 112 is provided to be movable by the second motor 232.

The third motor 233 and the third transmission mechanism 233a have structures similar to those of the third motor 133 and the third transmission mechanism 133a, respectively.

However, the third motor 233 is connected to the conveyance roller 119 and the ejection roller 123 through 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 conveyance roller 119 and the ejection roller 123 in accordance with a control signal from the processing circuit 150. The third transmission mechanism 233a includes one or a plurality of pulleys, belts, gears, etc., provided between the third motor 233, and the shaft 119a being the rotation axis of the conveyance roller 119 and the shaft 123a being the rotation axis of the ejection roller 123. The third transmission mechanism 133a transmits the driving force generated by the third motor 133 to the conveyance roller 119 and the ejection roller 123. Consequently, the third motor 133 causes the conveyance roller 119 and the ejection roller 123 to convey and eject a medium by rotating the conveyance roller 119 and the ejection roller 123.

The control module 151 and the determination module 152 in the medium conveying apparatus 200 execute the medium reading process illustrated in FIG. 8 and FIG. 9, and the multi feed determination process illustrated in FIG. 11.

In step S103, the control module 151 rotates the conveyance roller 119, a first facing roller 120, the ejection roller 123, and/or a second facing roller 124 by driving the third motor 233. In step S104, the control module 151 rotates the separation roller 116 and moves the regulating guide 112 from the set position to the release position by driving the second motor 232 to rotate the cam member 113. In step S105, the control module 151 rotates a feed roller 115 by driving a first motor 131. Consequently, when feeding of a medium starts, the control module 151 controls the first motor 131 and the second motor 232 such that the feed roller 115 rotates after the separation roller 116 in a rotating state contacts the medium. Further, when feeding of the medium starts, the control module 151 operates the first motor 131 after operating the second motor 232.

In step S107, the control module 151 controls the second motor 232 to stop the separation roller 116. In step S113, the control module 151 controls the second motor 232 to re-rotate the separation roller 116. In the steps above, the regulating guide 112 does not move from the release position. In step S114, the control module 151 controls the first motor 131 to re-rotate the feed roller 115. Consequently, when feeding of a second or subsequent medium out of media set on the regulating guide 112 is started, the control module 151 controls the first motor 131 and the second motor 232 such that the feed roller 115 rotates after the separation roller 116 rotates.

In step S120, the control module 151 controls the third motor 233 to stop the conveyance roller 119, the first facing roller 120, the ejection roller 123, and/or the second facing roller 124. In step S121, the control module 151 controls the second motor 232 to move the regulating guide 112 from the release position to the set position by rotating the cam member 113. At this time, the separation roller 116 rotates in a medium feeding direction. However, since no medium exists on a loading tray 103, no issue occurs.

In step S123, the control module 151 controls the first motor 131 to rotate the feed roller 115. In other words, when not feeding a medium, the control module 151 controls the first motor 131 or the second motor 232 to rotate the feed roller 115 while the regulating guide 112 is located at the set position. The control module 151 rotates the feed roller 115 to move substances adhered to the feed roller 115 or the separation roller 116. In step S124, the control module 151 controls the first motor 131 to stop the feed roller 115.

In S204, S205, and S208 of the multi feed determination process, the control module 151 controls the second motor 232 to stop or re-rotate the separation roller 116. In the steps above, the regulating guide 112 does not move from the release position.

As described in detail above, the medium conveying apparatus 200 can more satisfactorily separate media when driving the separation roller 116 and the regulating guide 112 by the common second motor 232 as well. Further, the medium conveying apparatus 200 can more suitably restore media when multi feed of the media occurred by driving the separation roller 116 and the regulating guide 112 with the common second motor 232 as well.

FIG. 14 is a diagram illustrating a schematic configuration of a processing circuit in a medium conveying apparatus according to yet another embodiment. The processing circuit 350 is used in place of the processing circuit 150 in the medium conveying apparatuses 100 and 200 and executes, in place of the processing circuit 150, the medium reading process, the multi feed determination process, etc. The processing circuit 350 includes a control circuit 351, a determination circuit 352, etc. Each component may be independently configured with an integrated circuit, a microprocessor, firmware, etc.

The control circuit 351 is an example of a control module and has a function similar to that of the control module 151. The control circuit 351 receives the operation signal from the operation device 105 or the interface device 135, the medium signal from the first medium sensor 111, the second medium signal from the second medium sensor 117, and the third medium signal from the third medium sensor 121. Further, the control circuit 351 receives a determination result of multi feed 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 the received information, acquires the input image from the imaging device 122, and outputs the acquired image to the interface device 135.

The determination circuit 352 is an example of a determination module and has a function similar to that of the determination module 152. The determination circuit 352 receives the ultrasonic signal from the ultrasonic sensor 118, determines whether multi feed of media has occurred, based on the received ultrasonic signal, and outputs the determination result to the control circuit 351.

As described in detail above, the medium conveying apparatus can satisfactorily separate media when the processing circuit 350 is used as well. Further, the medium conveying apparatus can more suitably restore media at occurrence of multi feed of the media when the processing circuit 350 is used as well.

According to the embodiments, the medium conveying apparatus, the method for feeding a medium and the computer-readable, non-transitory medium storing executable instructions according to the present embodiment enables more satisfactory separation of media.

All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a presentation of the superiority and inferiority of the invention. Although the embodiment(s) of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.

	Number	Date	Country
Parent	PCT/JP2022/003421	Jan 2022	WO
Child	18604146		US

MEDIUM CONVEYING DEVICE, MEDIUM FEEDING METHOD, AND CONTROL PROGRAM

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