MEDIUM CONVEYING DEVICE, CONTROL METHOD, AND CONTROL PROGRAM

Abstract

To appropriately detect a bound medium.SOLUTION: A medium conveying device includes: a separation roller for separating a medium; a plurality of medium detection sensors arranged along a direction orthogonal to a conveyance direction in a conveyance direction downstream of the medium against the separation roller; a plurality of overlapped detection sensors arranged at the conveyance direction downstream against each medium detection sensor to detect an overlapping with the medium; a determination part determining whether or not the medium is a bound medium on the basis of detection results of the plurality of medium detection sensors and the plurality of overlapped detection sensors; and a control part executing abnormality processing in the case where it is determined that the medium is the bound medium. The determination part determines that the medium is the bound medium in the case that after the medium detection sensor initially detecting the medium from the plurality of medium detection sensors, each overlapped detection sensor of the downstream side of the medium detection sensor does not detect the overlapped of the medium, and each overlapped detection sensor difference from each overlapped detection sensor detects an overlapping of the medium.SELECTED DRAWING: Figure 7

Description

[Technical field]

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

[0002] Generally, a media conveying device such as a scanner that conveys and captures media sequentially separates and feeds a plurality of media stacked on a loading platform. However, if a plurality of media are bound with staples or the like, the media may be damaged when the media are separated. Therefore, there is a demand for a media conveying device that can appropriately detect such bound media.

[0003] In order to prevent damage to original documents due to the transport of bound media, a media transport device is known that uses an ultrasonic sensor to detect overlapping of fed media and stops transport when overlapping of media is detected (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-132373 A Summary of the Invention [Problem to be solved by the invention]

[0005] There has been a demand for a medium conveying device that can more appropriately detect the presence of a bound medium and stop conveyance.

[0006] The objective of the medium conveying device, the control method, and the control program is to appropriately detect the medium to be bound. [Means for solving the problem]

[0007] The media conveying device of the embodiment has a separation roller for separating the media, multiple media detection sensors arranged downstream in the media conveying direction from the separation roller along a direction perpendicular to the conveying direction, multiple overlap detection sensors arranged downstream in the conveying direction from each media detection sensor for detecting overlapping of media, a determination unit that determines whether the medium is a bound medium based on the detection results of the multiple media detection sensors and the multiple overlap detection sensors, and a control unit that executes abnormality processing if it is determined that the medium is a bound medium, and the determination unit determines that the medium is a bound medium when, after the media detection sensor that first detected the medium among the multiple media detection sensors detected the medium, an overlap detection sensor downstream of the media detection sensor does not detect overlapping of media and an overlap detection sensor other than the overlap detection sensor detects overlapping of media.

[0008] A control method according to an embodiment is a control method for a media conveying device having a separation roller for separating media, multiple media detection sensors arranged downstream in the media conveying direction from the separation roller along a direction perpendicular to the conveying direction, and multiple overlap detection sensors arranged downstream in the conveying direction from each media detection sensor for detecting overlapping of media, the control method including determining whether the medium is a bound medium based on the detection results of the multiple media detection sensors and the multiple overlap detection sensors, and executing abnormality processing if it is determined that the medium is a bound medium, and in the determination, if the media detection sensor that first detected the medium among the multiple media detection sensors detects the medium, then the overlap detection sensor downstream of the media detection sensor does not detect overlapping of media, and an overlap detection sensor other than the overlap detection sensor detects overlapping of media, the control method determines that the medium is a bound medium.

[0009] The control program of the embodiment is a control program for a media conveying device having a separation roller for separating media, multiple media detection sensors arranged downstream in the media conveying direction from the separation roller along a direction perpendicular to the conveying direction, and multiple overlap detection sensors arranged downstream in the conveying direction from each media detection sensor for detecting overlapping of media, and causes the media conveying device to determine whether the medium is a bound medium based on the detection results of the multiple media detection sensors and the multiple overlap detection sensors, and if it is determined that the medium is a bound medium, perform abnormality processing.In the determination, if the media detection sensor that first detected the medium among the multiple media detection sensors detected the medium, and then the overlap detection sensor downstream of the media detection sensor does not detect overlapping of media, and an overlap detection sensor other than the overlap detection sensor detects overlapping of media, it is determined that the medium is a bound medium. Effect of the Invention

[0010] According to the embodiments, the medium conveying device, the control method, and the control program enable appropriate detection of the bound medium.

[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 of a medium conveying device 100 according to an embodiment. [Diagram 2] 2 is a diagram for explaining a medium transport path in the medium transport device 100. FIG. [Diagram 3] 11 is a diagram for explaining an example of the arrangement of a second medium sensor 115 and the like. FIG. [Figure 4] 1 is a block diagram showing a schematic configuration of a medium conveying device 100. FIG. [Diagram 5]FIG. 2 is a diagram showing a schematic configuration of a storage device 140 and a processing circuit 150. [Figure 6] FIG. 11 is a flow diagram showing an example of the flow of a medium reading process. [Figure 7] FIG. 11 is a flow diagram showing an example of the flow of a determination process. [Figure 8] FIG. 11 is a flow diagram showing an example of the flow of a determination process. [Figure 9] FIG. 11 is a flow diagram showing an example of the flow of a determination process. [Figure 10] 13A and 13B are diagrams for explaining a determination result when a binding medium is conveyed. [Figure 11] 13A and 13B are diagrams for explaining a determination result when a binding medium is conveyed. [Figure 12] 13A and 13B are diagrams for explaining a determination result when multiple feeding occurs. [Figure 13] 13A and 13B are diagrams for explaining a determination result when a card medium is transported. [Figure 14] 13 is a diagram for explaining another example of the arrangement of the second medium sensor 215 and the like. FIG. [Figure 15] 13A and 13B are diagrams for explaining a determination result when a binding medium is conveyed. [Figure 16] 13A and 13B are diagrams for explaining a determination result when a card medium is transported. [Figure 17] FIG. 2 is a diagram showing an example of a schematic configuration of a processing circuit 350. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, a medium conveying device, a control method, and a control program according to one aspect of the present invention 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] FIG. 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 or cardboard, etc. The medium also includes bound media in which multiple media are bound by staples, strings, clips, etc., and card media that are smaller and thicker than paper, such as driver's licenses and IC cards. The medium conveying device 100 may be a facsimile, a copier, a multifunction printer (MFP, Multifunction Peripheral), etc. The medium conveying device 100 may also be a printer, etc., in which case the conveyed medium is a print target, etc.

[0015] The medium conveying device 100 includes a first housing 101, a second housing 102, a placement table 103, a discharge table 104, an operation device 105, a display device 106, and the like.

[0016] The first housing 101 is disposed above the medium conveying device 100, and engages with the second housing 102 by a hinge so as to be openable and closable when a medium is jammed, when the inside of the medium conveying device 100 is cleaned, and the like.

[0017] The placement table 103 engages with the second housing 102 so that the transported media can be placed thereon. The placement table 103 is provided on the side of the second housing 102 on the media supply side so that it can move in a substantially vertical direction (height direction) A1 by a motor (not shown). The placement table 103 is disposed at a lower end position so that the media can be easily placed on it when the media is not being transported, and when the media is being transported, the placement table 103 rises to a position where the uppermost medium placed on the placement table 103 comes into contact with a pick roller (described later). The discharge table 104 is formed on the first housing 101 so as to be able to hold the discharged media, and stacks the discharged media.

[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] 1, arrow A2 indicates the medium transport direction, arrow A3 indicates the medium discharge direction, and arrow A4 indicates the width direction perpendicular to the medium transport direction. In the following, upstream refers to the upstream of the medium transport direction A2 or the medium discharge direction A3, and downstream refers to the downstream of the medium transport direction A2 or the medium discharge direction A3.

[0020] 2 is a diagram for explaining the conveying path inside the medium conveying device 100. The conveying path inside the medium conveying device 100 includes a first medium sensor 111, a pick roller 112, a feed roller 113, a brake roller 114, a plurality of second medium sensors 115A-C, a plurality of ultrasonic sensors 116A-C, first to eighth conveying rollers 117a-h, first to eighth driven rollers 118a-h, a first imaging device 119a, and a second imaging device 119b. Hereinafter, each of the second medium sensors 115A-C may be referred to as a second medium sensor 115. Also, each of the ultrasonic sensors 116A-C may be referred to as an ultrasonic sensor 116. Also, the first imaging device 119a and the second imaging device 119b may be collectively referred to as an imaging device 119.

[0021] The number of each of the pick roller 112, the feed roller 113, the brake roller 114, the first to eighth conveyor rollers 117a-h, and / or the first to eighth driven rollers 118a-h is not limited to one, and may be more than one. In this case, the multiple pick rollers 112, the feed roller 113, the brake roller 114, the first to eighth conveyor rollers 117a-h, and / or the first to eighth driven rollers 118a-h are arranged at intervals in the width direction A4.

[0022] The surface of first housing 101 facing second housing 102 forms first guide 101a of the medium transport path, and the surface of second housing 102 facing first housing 101 forms second guide 102a of the medium transport path.

[0023] The first medium sensor 111 is disposed on the mounting table 103, that is, upstream of the feed roller 113 and the brake roller 114, and detects the state of the medium on the mounting table 103. The first medium sensor 111 determines whether or not a medium is placed on the mounting table 103 by using a contact detection sensor that passes a predetermined current when the medium is in contact or not in contact. The first medium sensor 111 generates and outputs a first medium signal whose signal value changes depending on whether the medium is placed on the mounting table 103 or not. 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] Pick roller 112 is provided in first housing 101, and comes into contact with a medium placed on placement table 103 that is elevated to approximately the same height as the medium transport path, and feeds the medium downstream.

[0025] The feed roller 113 is provided in the first housing 101 downstream of the pick roller 112, and feeds the medium fed by the pick roller 112 further downstream. The brake roller 114 is provided in the second housing 102 facing the feed roller 113. The feed roller 113 and the brake roller 114 are an example of a separation roller, and perform a medium separation operation, separate the media, and feed them one by one. The feed roller 113 is provided above the brake roller 114, and the medium conveying device 100 feeds the media by a so-called top-take method.

[0026] The second medium sensor 115 is disposed downstream of the feed roller 113 and the brake roller 114 and upstream of the ultrasonic sensor 116. The second medium sensor 115 is an example of a medium detection sensor, and detects whether or not a medium is present at that position. The second medium sensor 115 is a regression prism sensor, and includes a light emitting element, a light receiving element, and a light guiding member.

[0027] The light emitting element and the light receiving element are disposed outside the medium transport path, sandwiching the second guide 102a. The light guiding member is a light guide tube such as a U-shaped prism, and is disposed outside the medium transport path, sandwiching the first guide 101a, with both ends facing the light emitting element and the light receiving element, respectively. The light emitting element is an LED (Light Emitting Diode) or the like, and irradiates light toward the light guiding member across the medium transport path. The light receiving element receives light irradiated from the light emitting element and guided by the light guiding member. The light receiving element generates and outputs a second medium signal, which is an electrical signal according to the intensity of the received light. When a medium is present at the position of the second medium sensor 115, the light irradiated from the light emitting element is blocked by the medium, so that the signal value of the second medium signal changes depending on whether a medium is present at the position of the second medium sensor 115 or not.

[0028] The configuration of second medium sensor 115 is not limited to the above example. For example, a reflective member such as a mirror may be used instead of the light guiding member. Second medium sensor 115 may be composed of only a light emitting element and a light receiving element. In this case, the light emitting element and the light receiving element are respectively arranged in first housing 101 and second housing 102 so as to face each other with the medium transport path in between. Second medium sensor 115 may also be a contact detection sensor similar to first medium sensor 111.

[0029] The ultrasonic sensor 116 is disposed downstream of the feed roller 113 and the brake roller 114 and upstream of the first to eighth conveyor rollers 117a-h and the first to eighth driven rollers 118a-h. The ultrasonic sensor 116 has an ultrasonic transmitter and an ultrasonic receiver. The ultrasonic transmitter and the ultrasonic receiver are disposed near the medium conveyance path and facing each other across the conveyance path. The ultrasonic transmitter is disposed outside the medium conveyance path across the first guide 101a, and the ultrasonic receiver is disposed outside the medium conveyance path across the second guide 102a. The ultrasonic transmitter emits ultrasonic waves. The ultrasonic receiver receives ultrasonic waves emitted by the ultrasonic transmitter and transmitted through the medium, and generates and outputs an ultrasonic signal, which is an electrical signal corresponding to the magnitude of the received ultrasonic waves.

[0030] The ultrasonic waves emitted by the ultrasonic transmitter are attenuated when passing through a medium. In particular, when ultrasonic waves pass through multiple media, they are significantly attenuated by the air layers of the multiple media, so that an overlap of media is detected based on the magnitude of the ultrasonic waves received by the ultrasonic receiver. The ultrasonic sensor 116 is an example of an overlap detection sensor for detecting an overlap of media.

[0031] The first to eighth transport rollers 117a-h and the first to eighth driven rollers 118a-h are provided downstream of the feed roller 113 and the brake roller 114, and transport the medium fed by the feed roller 113 and the brake roller 114 downstream. The first to eighth transport rollers 117a-h and the first to eighth driven rollers 118a-h are disposed opposite each other with the medium transport path in between.

[0032] The first imaging device 119a is provided downstream of the first and second transport rollers 117a-b and the first and second driven rollers 118a-b in the medium transport direction A2, that is, downstream of the ultrasonic sensor 116. The first imaging device 119a has a line sensor based on a CIS (Contact Image Sensor) of a life-size optical system type having imaging elements based on CMOS (Complementary Metal Oxide Semiconductor) linearly arranged in the main scanning direction. The first imaging device 119a has a lens that forms an image on the imaging element, and an A / D converter that amplifies and analog-to-digital (A / D) converts the electrical signal output from the imaging element. The first imaging device 119a captures an image of the surface of the medium being transported to generate an input image and output it.

[0033] The second imaging device 119b is provided downstream of the first and second transport rollers 117a-b and the first and second driven rollers 118a-b in the medium transport direction A2, that is, downstream of the ultrasonic sensor 116. The second imaging device 119b has a line sensor based on a CIS (Contact Image Sensor) of a life-size optical system type having imaging elements based on CMOS (Complementary Metal Oxide Semiconductor) linearly arranged in the main scanning direction. The second imaging device 119b 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 119b captures the back side of the medium being transported to generate an input image and output it.

[0034] The medium conveying device 100 may be arranged with only one of the first imaging device 119a and the second imaging device 119b, 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 medium placed on the mounting table 103 is transported between the first guide 101a and the second guide 102a in the medium transport direction A2 by the rotation of the pick roller 112 and the feed roller 113 in the medium feed directions A5 and A6, respectively. Meanwhile, when multiple media are placed on the mounting table 103, only the medium in contact with the feed roller 113 is separated from the media placed on the mounting table 103 by the rotation of the brake roller 114 in the direction A7 opposite to the medium feed direction. A torque limiter is provided on the brake roller 114. As a result, when only one medium is placed on the mounting table 103, the brake roller 114 does not prevent the medium from being transported in the medium transport direction A2.

[0036] The medium is guided by the first guide 101a and the second guide 102a, and as the first and second transport rollers 117a-b rotate in the directions of arrows A8-A9, the medium is sent to an imaging position of the imaging device 119 and is imaged by the imaging device 119. The medium is then discharged onto the discharge table 104 as the third to eighth transport rollers 117c-h rotate in the directions of arrows A10-A15, respectively. The discharge table 104 holds the media discharged by the eighth transport roller 117h.

[0037] Fig. 3 is a diagram for explaining an example of the arrangement of second medium sensor 115 and ultrasonic sensor 116. Fig. 3 is a schematic diagram of second housing 102 viewed from above with first housing 101 open.

[0038] 3, three second medium sensors 115A-C are arranged at intervals along the width direction A4 perpendicular to the medium transport direction A2 downstream of the brake roller 114 in the medium transport direction A2. All three second medium sensors 115A-C are arranged at approximately the same position in the medium transport direction A2.

[0039] 3, three ultrasonic sensors 116A-C are disposed downstream in the medium transport direction A2 from the second medium sensors 115A-C. Each ultrasonic sensor 116A-C is disposed so that at least a portion of each sensor overlaps with the second medium sensors 115A-C in the width direction A4, that is, so that at least a portion of each sensor overlaps with the second medium sensors 115A-C when viewed from the medium transport direction A2. All three ultrasonic sensors 116A-C are disposed at approximately the same position in the medium transport direction A2.

[0040] The number of second medium sensors 115 and ultrasonic sensors 116 is not limited to three, but may be any number equal to or greater than two.

[0041] 4 is a diagram showing an example of a schematic configuration of the medium conveying device 100. The medium conveying device 100 further includes a motor 131, an interface device 132, a storage device 140, a processing circuit 150, and the like, in addition to the above-mentioned configuration.

[0042] The motor 131 includes one or more motors, and rotates the pick roller 112, the feed roller 113, the brake roller 114, and the first to eighth transport rollers 117a-h to feed and transport the medium in response to a control signal from the processing circuit 150. The first to eighth driven rollers 118a-h may be provided so as to rotate by the driving force from the motor, rather than being rotated following the rotation of each transport roller.

[0043] The interface device 132 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 the scanned image and various information. Also, instead of the interface device 132, a communication unit having an antenna for 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. The predetermined communication protocol is, for example, a wireless LAN (Local Area Network).

[0044] 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, non-transitory 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.

[0045] The processing circuit 150 is a circuit that operates based on a program previously stored in the storage device 140. The processing circuit 150 is, for example, a CPU (Central Processing Unit). As the processing circuit 150, a DSP (digital signal processor), an LSI (large scale integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or the like may be used.

[0046] The processing circuit 150 is connected to the operation device 105, the display device 106, the first medium sensor 111, the second medium sensor 115, the ultrasonic sensor 116, the imaging device 119, the motor 131, the interface device 132, the storage device 140, etc., and controls each of these components. The processing circuit 150 controls the motor 131 to transport the medium, controls the imaging device 119 to obtain an input image, and transmits the obtained input image to the information processing device via the interface device 132. The processing circuit 150 also determines whether the transported medium is a binding medium based on the second medium signal received from the second medium sensor 115 and the ultrasonic signal received from the ultrasonic sensor 116.

[0047] FIG. 5 is a diagram showing a schematic configuration of the storage device 140 and the processing circuit 150. As shown in FIG.

[0048] The storage device 140 stores various programs such as a control program 141 and a determination program 142. Each of these programs is a functional module implemented by software that runs on a processor. The processing circuit 150 reads each of the programs stored in the storage device 140 and operates according to the read programs, thereby functioning as a control unit 151 and a determination unit 152. Note that the control unit 151 and the determination unit 152 may each be configured as an integrated circuit, a microprocessor, firmware, or the like that is independent of the processing circuit 150.

[0049] 6 is a flow diagram showing an example of the operation of a medium reading process executed by the medium conveying device 100. The medium reading process is realized by the processing circuit 150 cooperating with each element of the medium conveying device 100 based on a program stored in the storage device 140.

[0050] First, the control unit 151 waits until an operation signal instructing to read a medium is received (S101). The operation signal is supplied from the operation device 105 to the control unit 151 in response to a medium reading instruction being input by a user to the operation device 105. The operation signal may be supplied from the information processing device via the interface device 132 in response to a reading instruction being input by a user to the information processing device.

[0051] Next, control unit 151 determines whether or not a medium is placed on placement table 103 based on the first medium signal output from first medium sensor 111 (S102). If no medium is placed on placement table 103 (S102-No), control unit 151 ends the medium reading process.

[0052] If a medium is placed on the table 103 (S102-Yes), the control unit 151 drives a motor for moving the table 103, and raises the table 103 to a position where the medium can be fed. The control unit 151 drives the motor 131 to rotate the pick roller 112, the feed roller 113, the brake roller 114, and the first to eighth transport rollers 117a-h, and feeds and transports the medium placed on the table 103 (S103).

[0053] Next, the determination unit 152 executes a determination process (S104). In the determination process, the determination unit 152 determines whether the conveyed medium is a bound medium, whether a multiple feed has occurred, etc. The details of the determination process will be described later.

[0054] Next, the control unit 151 determines whether or not the conveyed medium is determined to be a binding medium in the determination process (S105). If the conveyed medium is determined to be a binding medium (S105-Yes), the control unit 151 outputs a notification that the medium is a binding medium (S106). The control unit 151 outputs the notification that the medium is a binding medium by displaying it on the display device 106, and notifies the user. The control unit 151 may output a notification signal indicating the notification that the medium is a binding medium by transmitting it to the information processing device via the interface device 132, and notify the user. Next, the control unit 151 stops the motor 131 to stop the conveyance of the medium (S112), and ends the medium reading process. Note that outputting the notification that the medium is a binding medium and stopping the conveyance of the medium are examples of abnormal processing.

[0055] The control unit 151 can prevent the occurrence of a medium jam and damage to the medium by stopping the transport of the medium when the bound medium is transported. The control unit 151 can also prevent the staples, clips, etc. that have bound the medium from entering the transport path of the medium and damaging the glass surface of the imaging device 119. This eliminates the need for the user to check whether the medium to be transported is stapled or not before transporting the medium, and the medium transport device 100 can improve user convenience and reduce the processing time of the medium reading process.

[0056] When it is determined that the transported medium is not a bound medium (S105-No), the control unit 151 determines whether or not the trailing edge of the medium has passed the imaging position of the imaging device 119 (S107). For example, the control unit 151 periodically acquires a second medium signal from each second medium sensor 115, and when the signal value of any of the second medium signals 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 trailing edge of the medium has passed the imaging position when a predetermined time has elapsed since the trailing edge of the medium passed the position of the second medium sensor 115. The predetermined time is set to a time that the medium takes to be transported from the second medium sensor 115 to the imaging position plus a margin. When the trailing edge of the medium has not yet passed the imaging position (S107-No), the control unit 151 returns the process to S104 and repeats the processes of S104 to S107.

[0057] When the rear end of the medium has passed the imaging position (S107-Yes), the control unit 151 acquires an input image from the imaging device 119. The control unit 151 transmits the acquired input image to the information processing device via the interface device 132 (S108).

[0058] Next, the control unit 151 determines whether or not it is determined in the determination process that a multi-feed of media has occurred (S109). If it is determined that a multi-feed of media has occurred (S109-Yes), the control unit 151 outputs a notification that a multi-feed has occurred (S110). The control unit 151 outputs the notification that a multi-feed has occurred by displaying it on the display device 106, and notifies the user. The control unit 151 may output a notification signal indicating the notification that a multi-feed has occurred by transmitting it to the information processing device via the interface device 132, and notify the user. Next, the control unit 151 stops the motor 131 to stop the transport of the media (S112), and ends the media reading process. Note that outputting the notification that a multi-feed has occurred and stopping the transport of the media are examples of abnormality processing.

[0059] Note that control unit 151 may stop motor 131 after a predetermined time has elapsed since the input image was transmitted in S108. The predetermined time is a time, including a margin, from the time until the medium that has passed the position of imaging device 119 is discharged from medium conveying device 100 and placed on discharge tray 104. This prevents the medium from remaining inside medium conveying device 100 when motor 131 is stopped.

[0060] Next, control unit 151 determines whether or not a medium is placed on placement table 103 based on the first medium signal output from first medium sensor 111 (S111). If a medium is placed on placement table 103 (S111-Yes), control unit 151 returns the process to S104 and repeats the processes of S104 to S111. If no medium is placed on placement table 103 (S111-No), control unit 151 stops motor 131 (S112) and ends the medium reading process.

[0061] 7 to 9 are flow charts showing an example of the operation of the determination process. The determination process is executed in S104 of FIG.

[0062] During the execution of the determination process, the determination unit 152 periodically determines whether each second medium sensor 115 has detected a medium in parallel with the determination process. The determination unit 152 periodically acquires a second medium signal from each second medium sensor 115, and when the signal value of each second medium signal changes from a value indicating the absence of a medium to a value indicating the presence of a medium, the determination unit 152 determines that the second medium sensor 115 has detected a medium. Furthermore, during the execution of the determination process, the determination unit 152 periodically determines whether each ultrasonic sensor 116 has detected an overlap of media in parallel with the determination process. The determination unit 152 periodically acquires an ultrasonic signal from each ultrasonic sensor 116, and when the signal value of each ultrasonic signal is equal to or less than the overlap threshold, the determination unit 152 determines that the ultrasonic sensor 116 has detected an overlap of media. The overlap threshold is set to a value between the signal value of the ultrasonic signal output when one PPC (Plain Paper Copier) sheet is conveyed and the signal value of the ultrasonic signal output when two PPC sheets are conveyed.

[0063] First, as shown in FIG. 7, the determination unit 152 waits until any one of the plurality of second medium sensors 115 detects a medium (S201).

[0064] When any of the second media sensors 115 detects a medium, the determination unit 152 determines whether the ultrasonic sensor 116 downstream of the second media sensor 115 has detected an overlap of media (S202). The ultrasonic sensor 116 downstream of the second media sensor 115 is the ultrasonic sensor 116 arranged corresponding to the second media sensor 115, and is arranged so that at least a portion of the ultrasonic sensor 116 overlaps with the second media sensor 115 when viewed from the upstream side of the medium transport direction A2. The determination unit 152 continues to determine whether the ultrasonic sensor 116 has detected an overlap of media until the first time has elapsed since the second media sensor 115 detected the medium or the ultrasonic sensor 116 detects an overlap of media. The first time is set to the time it takes for the medium to be transported from the second media sensor 115 to the ultrasonic sensor 116 plus a margin.

[0065] If the ultrasonic sensor 116 does not detect an overlap of media before the first time has elapsed (S202-No), as shown in FIG. 8, the determination unit 152 determines whether or not another second medium sensor 115 has detected a medium (S203). The other second medium sensor 115 is a second medium sensor 115 different from the second medium sensor 115 that first detected the medium. The determination unit 152 continues to determine whether or not each of the other second medium sensors 115 has detected a medium until the second time has elapsed since the second medium sensor 115 that first detected the medium detected the medium, or until each of the other second medium sensors 115 detects the medium. The second time is set to a time that is a margin added to the time difference between the times when the leading edge of the medium reaches the position of each of the second medium sensors 115 when the medium is transported tilted at the maximum angle guaranteed by the medium transport device 100.

[0066] If none of the other second media sensors 115 detects a medium before the second time has elapsed (S203-No), the determination unit 152 determines that the medium is a small medium such as a receipt and that multiple media feeds have not occurred (S204), and ends the determination process. A small medium is a medium with at least one side having a length shorter than the arrangement interval of the multiple second media sensors 115.

[0067] If any of the other second medium sensors 115 detects a medium before the second time has elapsed (S203-Yes), the determination unit 152 determines whether or not each ultrasonic sensor 116 downstream of the second medium sensor 115 that detected the medium has detected overlapping media (S205). The determination unit 152 continues to determine whether or not each ultrasonic sensor 116 has detected overlapping media until the first time has elapsed since the other second medium sensor 115 detected the medium or until each ultrasonic sensor 116 detects overlapping media.

[0068] If any of the ultrasonic sensors 116 detects overlapping of media before the first time has elapsed (S205-Yes), the determination unit 152 determines that the media are binding media (S206) and ends the determination process. In this manner, the determination unit 152 determines whether the media are binding media or not based on the detection results of the multiple second media sensors 115 and the multiple ultrasonic sensors 116. In particular, the determination unit 152 determines that the media are binding media when the second media sensor 115 that first detected the media among the multiple second media sensors 115 detects the media, and then the ultrasonic sensor 116 downstream of the second media sensor 115 does not detect overlapping of media and an ultrasonic sensor 116 other than the first ultrasonic sensor 116 detects overlapping of media.

[0069] If none of the ultrasonic sensors 116 detects overlapping media before the first time has elapsed (S205-No), the determination unit 152 determines that the media are normal media and that double feeding of media has not occurred (S207), and ends the determination process. A normal medium is a medium that is neither bound nor card media, and is larger than a small medium.

[0070] If the ultrasonic sensor 116 downstream of the second media sensor 115 that first detected the medium detects overlapping media before the first time has elapsed (S202-Yes), the determination unit 152 determines that the medium is not a bound medium (S208), as shown in Fig. 9. In this manner, the determination unit 152 determines that the medium is not a bound medium when the second media sensor 115 that first detected the medium among the multiple second media sensors 115 detects the medium and then the ultrasonic sensor 116 downstream of the second media sensor 115 detects overlapping media.

[0071] Next, determination unit 152 determines whether or not another second medium sensor 115 has detected a medium (S209). Determination unit 152 continues to determine whether or not another second medium sensor 115 has detected a medium until a second time has elapsed since the second medium sensor 115 that first detected the medium detected the medium or until another second medium sensor 115 detects the medium.

[0072] If none of the other second media sensors 115 detects the medium before the second time has elapsed (S209-No), the determination unit 152 determines that the medium is a card medium and that a double feed of media has not occurred (S210), and ends the determination process. Because card media are thick, ultrasonic waves that pass through the card medium are significantly attenuated, and the signal value of the ultrasonic signal may fall below the overlap threshold. However, because card media are small in size, the determination unit 152 can accurately determine whether a double feed of media has occurred or whether the card medium is being transported by determining whether multiple second media sensors 115 have detected the medium.

[0073] If any of the other second medium sensors 115 detects a medium before the second time has elapsed (S209-Yes), the determination unit 152 determines whether or not each ultrasonic sensor 116 downstream of the second medium sensor 115 that detected the medium has detected overlapping media (S211). The determination unit 152 continues to determine whether or not each ultrasonic sensor 116 has detected overlapping media until the first time has elapsed since the other second medium sensor 115 detected the medium or until each ultrasonic sensor 116 detects overlapping media.

[0074] If any of the ultrasonic sensors 116 does not detect an overlap of media before the first time has elapsed (S211-No), the determination unit 152 determines that a double feed of a normal medium and a small medium has occurred (S212) and ends the determination process. In this case, the determination unit 152 may determine that a sticker, stamp, or other attachment is affixed to the medium and that a double feed of media has not occurred.

[0075] If all ultrasonic sensors 116 detect overlapping media before the first time has elapsed (S211-Yes), the determination unit 152 determines that a double feed of normal media has occurred (S213) and ends the determination process. In this manner, the determination unit 152 determines that a double feed of media has occurred when the first second media sensor 115 among the multiple second media sensors 115 detects a medium, and then an ultrasonic sensor 116 downstream of the second media sensor 115 detects overlapping media, and an ultrasonic sensor 116 other than the first ultrasonic sensor 116 also detects overlapping media. This allows the determination unit 152 to determine with high accuracy whether a double feed of media has occurred.

[0076] In addition, in S209, when the number of the second medium sensors 115 that detected the medium is less than the specific number, the determination unit 152 may determine that the medium is a card medium in S210, and may move the process to S211 when the number of the second medium sensors 115 that detected the medium is equal to or greater than the specific number. The specific number is preset to a number equal to or greater than 2. In this case, even when the number of the second medium sensors 115 that detected the medium is less than the specific number, the determination unit 152 may determine whether or not each ultrasonic sensor 116 downstream of each second medium sensor 115 that detected the medium detected overlapping media. When any of the ultrasonic sensors 116 downstream of each second medium sensor 115 that detected the medium did not detect overlapping media, the determination unit 152 determines that multiple feeding of small media has occurred. On the other hand, when all of the ultrasonic sensors 116 downstream of each second medium sensor 115 that detected the medium detected overlapping media, the determination unit 152 determines that the medium is a card medium. In this way, the determination unit 152 determines that the medium is a card medium when only a predetermined number of the ultrasonic sensors 116 among the multiple ultrasonic sensors 116 detect overlapping media. This allows the determination unit 152 to determine with high accuracy whether the transported medium is a card medium or not.

[0077] Alternatively, the processes of S203 to S204 may be omitted, and in S205, the determination unit 152 may determine whether or not an ultrasonic sensor 116 other than the ultrasonic sensor 116 downstream of the second medium sensor 115 that first detected the medium has detected overlapping media. Similarly, the processes of S209 to S210 may be omitted, and in S211, the determination unit 152 may determine whether or not an ultrasonic sensor 116 other than the ultrasonic sensor 116 downstream of the second medium sensor 115 that first detected the medium has detected overlapping media. Alternatively, the processes of S209 to S211 may be omitted, and the determination unit 152 may determine that multiple feeding of media has occurred if the ultrasonic sensor 116 downstream of the second medium sensor 115 that first detected the medium has detected overlapping media.

[0078] In the following, detection results of the second medium sensor 115 and the ultrasonic sensor 116 when various types of media are transported in the example of the sensor arrangement shown in FIG. 3 will be described.

[0079] 10(A) to 10(D) are schematic diagrams for explaining examples of detection results of the sensor when the binding medium is transported. Fig. 10(A) is a diagram seen from above showing a state in which the binding medium M1, in which multiple media are bound, is fed and the leading end in the medium transport direction A2 reaches the positions of the feed roller 113 and the brake roller 114. The binding medium M1 is bound with one end (upper right end) on the downstream side in the medium transport direction A2 as the binding position S.

[0080] FIG. 10B is a diagram showing a state after time has elapsed since FIG. 10A. The medium M2, which is bound at the top of the binding medium M1 and is in contact with the feed roller 113, is pushed out in the medium conveying direction A2 by the feed roller 113. On the other hand, the medium M3 of the binding medium M1 that is not in contact with the feed roller 113 receives a force in the opposite direction to the conveying direction A2 by the brake roller 114 and is kept in place. As a result, as shown in FIG. 10B, the medium M2 rotates around the binding position S so that the end (upper left end) opposite the binding position S in the width direction A4 advances in the medium conveying direction A2, and reaches the position of the second medium sensor 115A arranged opposite the binding position S in the width direction A4. As a result, the second medium sensor 115A detects the medium first among the second medium sensors 115A to C.

[0081] Fig. 10(C) is a diagram showing a state after further time has passed from Fig. 10(B). Medium M2 is pushed further in the medium transport direction A2 by the feed roller 113. As a result, as shown in Fig. 10(C), medium M2 reaches the position of ultrasonic sensor 116A downstream of second medium sensor 115A that first detected the medium. In this state, only medium M2 has reached the position of ultrasonic sensor 116A, so ultrasonic sensor 116A does not detect an overlap of media.

[0082] As a result of medium M2 being pushed out in the medium transport direction A2, medium M3 is subjected to a force pulling it in the medium transport direction A2 from medium M2 at the binding position S. At the same time, medium M3 is subjected to a force in the opposite direction to the medium transport direction A2 by the brake roller 114. As a result, as shown in Fig. 10(C), medium M3 rotates around the point of contact with the brake roller 114 so that the end (upper right end) on the binding position S side in the width direction A4 advances in the medium transport direction A2.

[0083] Fig. 10(D) is a diagram showing a state after further time has passed from Fig. 10(C). Medium M2 is pushed further in the medium transport direction A2 by the feed roller 113. Furthermore, medium M3 is pulled by medium M2 through the binding position S and advances in the medium transport direction A2 against the rotational force of the brake roller 114. As a result, medium M3 reaches the position of the ultrasonic sensor 116C arranged on the binding position S side in the width direction A4. Since medium M2 and medium M3 overlap at the position of the ultrasonic sensor 116C, the ultrasonic sensor 116C detects the overlap.

[0084] 10(A) to 10(D), when the binding medium M1 is transported, the second medium sensor 115A arranged on the opposite side of the binding position S in the width direction A4 detects the medium first. Then, the ultrasonic sensor 116A downstream of the second medium sensor 115A that first detects the medium does not immediately detect the overlap of the media, but the ultrasonic sensor 116C arranged on the binding position S side in the width direction A4 detects the overlap of the media immediately. Note that examples of the detection results of the second medium sensor 115 and the ultrasonic sensor 116 when the binding medium is transported are not limited to the above-mentioned examples.

[0085] 11(A) and (B) are diagrams for explaining the detection result of the sensor when a binding medium M1 smaller than the example shown in FIG. 10 is conveyed. FIG. 11(A) is a diagram showing a state corresponding to FIG. 10(B). As shown in FIG. 11(A), the medium M2 bound at the top of the binding medium M1 rotates around the binding position S and reaches the position of the second medium sensor 115A arranged on the opposite side of the binding position S in the width direction A4. As a result, of the second medium sensors 115A to 115C, the second medium sensor 115A detects the medium first.

[0086] Fig. 11(B) is a diagram showing a state corresponding to Fig. 10(D). As shown in Fig. 11(B), medium M3 is pulled by medium M2 through the binding position S and advances in the medium conveying direction A2 against the rotational force of the brake roller 114. Since the width of medium M3 is smaller than that of the example shown in Fig. 10(D), medium M3 does not reach the position of ultrasonic sensor 116C arranged on the binding position S side in the width direction A4 as shown in Fig. 11(B), but reaches the position of ultrasonic sensor 116B arranged in the center. Since medium M2 and medium M3 overlap at the position of ultrasonic sensor 116B, ultrasonic sensor 116B detects the overlap.

[0087] 11(A)-(B), when a small binding medium M1 is transported, the second medium sensor 115A arranged on the opposite side of the binding position S in the width direction A4 detects the medium first. Then, the ultrasonic sensor 116A downstream of the second medium sensor 115A that first detects the medium does not immediately detect the overlap of the media, but the ultrasonic sensor 116B arranged in the center in the width direction A4 detects the overlap of the media immediately.

[0088] 10 and 11, different ultrasonic sensors 116 detect overlapping media depending on the size of the media. However, in either case, when the binding media is transported, the ultrasonic sensor 116 downstream of the second media sensor 115 that first detected the media does not immediately detect the overlapping media, but an ultrasonic sensor 116 different from that ultrasonic sensor 116 immediately detects the overlapping media. Therefore, the binding media is appropriately detected by S202, S203, and S205 of the determination process.

[0089] Figures 12(A) and (B) are schematic diagrams for explaining the detection results of the sensors when a card medium is transported. Figure 12(A) is a diagram showing a state in which card medium M4 has been fed and has reached the position of second medium sensor 115. As shown in Figure 12(A), card medium M4 has reached the position of second medium sensor 115B in the center in width direction A4, so second medium sensor 115B detects the medium.

[0090] FIG. 12(B) is a diagram showing a state after time has passed since FIG. 12(A). As shown in FIG. 12(B), the card medium M4 has reached the position of the ultrasonic sensor 116B downstream of the second medium sensor 115B that detected the medium. Because the card medium M4 is thicker than a normal medium, the ultrasonic sensor 116B detects the overlap of the medium. As shown in FIG. 12(B), the card medium M4 is smaller in the width direction A4 than a normal medium, so it does not reach the positions of the second medium sensors 115A, C and the ultrasonic sensors 116A, C located on the end side in the width direction A4. Therefore, the second medium sensors 115A, C do not detect the medium, and the ultrasonic sensors 116A, C do not detect the overlap of the medium.

[0091] 12, when card medium M4 is transported, only the second medium sensor 115B located at the center in the width direction A4 detects the medium. Then, only the ultrasonic sensor 116B downstream of the second medium sensor 115B that detected the medium detects the overlap of the media.

[0092] In the example shown in FIG. 12, since the width of the card medium M4 is smaller than the distance in the width direction A4 between adjacent second media sensors 115, only one second media sensor 115 detects the medium, and only one ultrasonic sensor 116 detects the overlap of the media. However, depending on the relationship between the width of the card medium and the distance in the width direction of the second media sensor 115, multiple second media sensors 115 may detect the medium, or multiple ultrasonic sensors 116 may detect the overlap of the media. In other words, when the card medium is transported, only a predetermined number of second media sensors 115 (one in the example shown in FIG. 12) including the second media sensor 115 that first detected the medium detects the medium, and only the ultrasonic sensor downstream of each second media sensor 115 that detected the medium detects the overlap of the media. The predetermined number is appropriately determined based on the relationship between the width of the card medium supported by the medium transport device 100 and the distance in the width direction of the second media sensor 115. Therefore, the card medium is appropriately detected by S202 and S209 of the determination process.

[0093] Figures 13(A) and (B) are schematic diagrams for explaining the detection results of the sensors when a double feed occurs. Figure 13(A) is a diagram showing a state in which multiple media M5 are transported overlapping each other and reach the position of the second medium sensor 115. As shown in Figure 13(A), since the medium M5 reaches the positions of the second medium sensors 115A to C, the second medium sensors 115A to C detect the medium almost simultaneously. In the following description, it is assumed that the second medium sensor 115A detects the medium first.

[0094] Figure 13(B) is a diagram showing a state after time has passed from Figure 13(A). As shown in Figure 13(B), media M5 are transported in the medium transport direction A2 in an overlapping state, and reach the positions of ultrasonic sensors 116A-C. As a result, ultrasonic sensors 116A-C each detect the overlap of the media.

[0095] 13, when a double feed occurs, the ultrasonic sensor 116A located downstream of the second medium sensor 115A that first detected the medium detects the overlap of the media, and the other ultrasonic sensors 116A and 116C also detect the overlap of the media. Therefore, the occurrence of a double feed is appropriately detected by S202 and S211 of the determination process.

[0096] As described above, the medium conveying device 100 according to the embodiment determines whether or not the conveyed medium is a binding medium by using the multiple second medium sensors 115 and the multiple ultrasonic sensors 116. This enables the medium conveying device 100 to appropriately detect the binding medium.

[0097] Furthermore, the medium conveying device 100 detects the binding medium without detecting the lifting of the medium. This enables the medium conveying device 100 to detect the binding medium with high accuracy. Furthermore, the medium conveying device 100 detects the binding medium using only a medium detection sensor and an overlap detection sensor that are included in a general medium conveying device, so that it is possible to detect the binding medium while suppressing an increase in device cost and component mounting space.

[0098] FIG. 14 is a diagram for explaining another example of the arrangement of the second medium sensor 215 and the ultrasonic sensor 216. In FIG.

[0099] 14, instead of the multiple second medium sensors 115A-C and the multiple ultrasonic sensors 116A-C, multiple second medium sensors 215A-D and multiple ultrasonic sensors 216A-D are provided. Below, each of the second medium sensors 215A-D may be referred to as a second medium sensor 215. Also, each of the ultrasonic sensors 216A-D may be referred to as an ultrasonic sensor 216. Each of the second medium sensors 215 has a similar configuration to the second medium sensor 115. Also, each of the ultrasonic sensors 216 has a similar configuration to the ultrasonic sensor 116.

[0100] The four second medium sensors 215A-D are arranged at intervals along the width direction A4 perpendicular to the transport direction. Of the four second medium sensors 215A-D, second medium sensors 215B and C arranged in the center in the width direction A4 are arranged further downstream in the medium transport direction A2 than second medium sensors 215A and D arranged on the end sides.

[0101] The four ultrasonic sensors 216A-D are arranged downstream in the medium transport direction A2 from the second medium sensors 215A-D. Each ultrasonic sensor 216A-D is arranged so that at least a portion of it overlaps with each second medium sensor 215A-D in the width direction A4, that is, so that at least a portion of it overlaps with each second medium sensor 215A-D when viewed from the medium transport direction A2. Of the four ultrasonic sensors 216A-D, ultrasonic sensors 216B and C arranged in the center in the width direction A4 are arranged further downstream in the medium transport direction A2 than the ultrasonic sensors 216A and D arranged on the end sides.

[0102] The number of second medium sensors 215 and ultrasonic sensors 216 is not limited to four, but may be any number equal to or greater than three.

[0103] 14, second media sensors 215A and D, which are disposed outboard of brake roller 114 in width direction A4, are disposed downstream of the downstream end of brake roller 114 in medium transport direction A2. This example is not limiting, and second media sensors 215A and D may be disposed upstream of the downstream end of brake roller 114 in medium transport direction A2. Furthermore, ultrasonic sensors 216A and D, which are located downstream of second media sensors 215A and D, respectively, may be disposed upstream of the downstream end of brake roller 114 in medium transport direction A2.

[0104] Figures 15(A) to (D) are diagrams for explaining the detection results of the sensors when the binding medium is transported in the example of the sensor arrangement shown in Figure 14. Figure 15(A) is a diagram showing a state in which the binding medium M1 is placed on one side (the binding position S side) on the placement table 103 and transported, and the leading end in the medium transport direction A2 reaches the positions of the feed roller 113 and the brake roller 114.

[0105] FIG. 15(B) is a diagram showing a state after time has elapsed since FIG. 15(A). The medium M2, which is bound at the top of the binding medium M1 and is in contact with the feed roller 113, is pushed out in the medium conveying direction A2 by the feed roller 113. On the other hand, the medium M3 of the binding medium M1 that is not in contact with the feed roller 113 receives a force in the opposite direction to the medium conveying direction A2 by the brake roller 114 and is kept in place. As a result, as shown in FIG. 15(B), the medium M2 rotates around the binding position S so that the end (upper left end) opposite the binding position S in the width direction A4 advances in the medium conveying direction A2, and reaches the position of the second medium sensor 215B arranged in the center in the width direction A4. As a result, of the second medium sensors 215A to D, the second medium sensor 215B detects the medium first.

[0106] Fig. 15(C) is a diagram showing a state after further time has passed since Fig. 15(B). Medium M2 is pushed further in the medium transport direction A2 by the feed roller 113. As a result of medium M2 being pushed in the medium transport direction A2, medium M3 is subjected to a force pulling it in the medium transport direction A2 from medium M2 at the binding position S. At the same time, medium M3 is subjected to a force in the opposite direction to the medium transport direction A2 by the brake roller 114. As a result, as shown in Fig. 15(C), medium M3 rotates around the point of contact with the brake roller 114 so that the end (upper right end) on the binding position S side in the width direction A4 advances in the medium transport direction A2.

[0107] Fig. 15(D) is a diagram showing a state after further time has passed from Fig. 15(C). Medium M2 is pushed further in the medium transport direction A2 by the feed roller 113. Furthermore, medium M3 is pulled by medium M2 through the binding position S and advances in the medium transport direction A2 against the rotational force of the brake roller 114. As a result, medium M3 reaches the position of the ultrasonic sensor 216D arranged on the binding position S side in the width direction A4. Because medium M2 and medium M3 overlap at the position of the ultrasonic sensor 216D, the ultrasonic sensor 216D detects the overlap.

[0108] 15(A) to 15(D), when the binding medium M1 is transported, the second medium sensor 215B detects the medium first. Then, the ultrasonic sensor 216B downstream of the second medium sensor 215B that first detected the medium does not immediately detect the overlap of the medium, but the ultrasonic sensor 216D arranged on the binding position S side in the width direction A4 immediately detects the overlap of the medium.

[0109] In particular, in this embodiment, the second medium sensors 215A, D and the ultrasonic sensors 216A, D arranged at both ends in the width direction A4 are arranged upstream of the second medium sensors 215B, C and the ultrasonic sensors 216B, C arranged in the center. As described above, when the binding medium M1 is conveyed toward the binding position S, the leading edge of the separated medium M2 is first detected by the second medium sensors 215B, C arranged in the center. On the other hand, since the binding position S of the binding medium M1 faces the ultrasonic sensor 216D arranged at the end in the width direction A4, the overlap of the binding medium M1 is detected by the ultrasonic sensor 216D. In this embodiment, by arranging the ultrasonic sensor 216D arranged at the end in the width direction A4 on the upstream side, the determination unit 152 can detect the overlap of the media earlier and stop the conveyance of the media earlier, thereby suppressing the occurrence of damage to the media. Furthermore, by arranging the ultrasonic sensors 216B and 216C at the center in the width direction A4 on the downstream side, it takes a sufficient amount of time for the leading edge of the medium M3 remaining on the upstream side to reach the position of the ultrasonic sensors 216B and 216C at the center. Therefore, the determination unit 152 can be prevented from erroneously determining that a double feed of unstitched media has occurred even though bound media is being transported, and from damaging the media without stopping the transport of the media.

[0110] In addition, by reducing the spacing between the multiple second media sensors 215 and the multiple ultrasonic sensors 216, the media conveying device can detect the binding medium well even if the size of the binding medium in the width direction A4 is small, thereby improving the detection accuracy of the binding medium.

[0111] Figures 16(A) and (B) are schematic diagrams for explaining the detection results of the sensors when a card medium is transported in the example of the sensor arrangement shown in Figure 14. Figure 16(A) is a diagram showing a state in which card medium M4 has been fed and has reached the position of second medium sensor 215. As shown in Figure 16(A), card medium M4 has reached the positions of second medium sensors 215B and C in the center in the width direction A4, so that second medium sensors 215B and C detect the medium.

[0112] Fig. 16(B) is a diagram showing a state after time has passed since Fig. 16(A). In Fig. 16(B), card medium M4 has reached the positions of ultrasonic sensors 216B and C downstream of second medium sensors 215B and C that detected the medium. Because card medium M4 is thicker than normal media, ultrasonic sensors 216B and C each detect overlapping media. On the other hand, card medium M4 is smaller than normal media in width direction A4, so it does not reach the positions of second medium sensors 215A, D and ultrasonic sensors 216A, D. Therefore, second medium sensors 215A, D do not detect the medium, and ultrasonic sensors 216A, D do not detect overlapping media.

[0113] As explained using Fig. 16, when a card medium M4 is transported, only the second medium sensors 215B and C located at the center in the width direction A4 detect the medium. Then, only the ultrasonic sensors 216B and C downstream of the second medium sensors 215B and C that detected the medium detect overlapping of the media. In other words, when a card medium is transported, only a predetermined number of second medium sensors 215 (two in the example shown in Fig. 16) including the second medium sensor 215 that first detected the medium detect the medium, and only the ultrasonic sensors 216 downstream of each second medium sensor 215 that detected the medium detect overlapping of the media.

[0114] In this way, the medium conveying device can appropriately detect the bound medium even when the multiple second medium sensors 215 and the multiple ultrasonic sensors 216 are arranged with a shift in the medium conveying direction A2.

[0115] In the above-described embodiment, an ultrasonic sensor is used as the overlap detection sensor, but a thickness sensor that detects the thickness of the medium may be used as the overlap detection unit. The thickness sensor is disposed at a position where each ultrasonic sensor is disposed. The thickness sensor includes a pair of a light emitter and a light receiver provided on one side of the medium transport path, and a pair of a light emitter and a light receiver provided on the other side. The thickness sensor detects the distance between each pair and each surface of the medium from the time from when one pair irradiates light on one surface of the medium to when it receives the reflected light, and the time from when the other pair irradiates light on the other surface of the medium to when it receives the reflected light. The thickness sensor generates a signal indicating a subtraction value obtained by subtracting each detected distance from the distance between the two pairs as a thickness signal corresponding to the thickness of the medium.

[0116] In this case, in the determination process, the determination unit 152 periodically acquires a thickness signal from each thickness sensor, and when the signal value of each thickness signal is equal to or greater than the thickness threshold, determines that the thickness sensor has detected an overlap of media. The thickness threshold is set to a value between the signal value of the thickness signal output when one PPC sheet is conveyed and the signal value of the thickness signal output when two PPC sheets are conveyed.

[0117] In addition, in the above-described embodiment, the feed roller 113 is positioned above the brake roller 114 and feeds the media placed on the mounting table 103 in sequence from the top, but the feed roller may be positioned below the brake roller so as to feed the media placed on the mounting table in sequence from the bottom.

[0118] 17 is a diagram showing a schematic configuration of a processing circuit 350 in a medium conveying device according to another embodiment. The processing circuit 350 is used in place of the processing circuit 150 of the medium conveying device 100, and executes a medium reading process. The processing circuit 350 has a control circuit 351, a determination circuit 352, and the like. Each of these components may be formed of an independent integrated circuit, microprocessor, firmware, and the like.

[0119] 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, a first medium signal from the first medium sensor 111, and a determination result in the determination process from the determination circuit 352, and controls the motor 131 based on the received signals and the determination result. The control circuit 351 also receives an input image from the imaging device 119, stores it in the storage device 140, and transmits it to the information processing device via the interface device 132.

[0120] 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 a second medium signal and an ultrasonic signal from the second medium sensor 115 and the ultrasonic sensor 116, respectively. Based on the received signals, the determination circuit 352 determines whether the medium is a bound medium and whether a double feed of media has occurred, and outputs the determination result to the control circuit 351.

[0121] As described above, the medium conveying device is capable of appropriately detecting the bound medium even when the processing circuit 350 is used.

[0122] It should be understood by those skilled in the art that various changes, substitutions, and modifications can be made to the present invention without departing from the spirit and scope of the present invention. For example, the above-mentioned embodiments and modifications may be appropriately combined within the scope of the present invention. [Explanation of symbols]

[0123] 100 Media transport device 113 Feeding roller 115 Second Media Sensor 116 Ultrasonic Sensor 151 Control section 152 Judgment section

Claims

1. a separation roller for separating the media; a plurality of medium detection sensors disposed downstream of the separation roller in a medium transport direction and along a direction perpendicular to the transport direction; a plurality of overlap detection sensors disposed downstream of each of the medium detection sensors in the transport direction for detecting overlap of the medium; a determination unit that determines whether the medium is a bound medium based on detection results of the plurality of medium detection sensors and the plurality of overlap detection sensors; A control unit that stops conveyance of the medium when the medium is determined to be a binding medium, the determination unit determines that the medium is a bound medium when, after a medium detection sensor that first detects a medium among the plurality of medium detection sensors detects the medium, an overlap detection sensor downstream of the medium detection sensor does not detect an overlap of media, and an overlap detection sensor different from the medium detection sensor detects an overlap of media. A medium transport device comprising:

2. The medium conveying device according to claim 1, wherein the determination unit determines that the medium is not a bound medium when an overlap detection sensor downstream of a media detection sensor that first detects a medium detects the medium after the media detection sensor detects an overlap of media.

3. 3. The medium transport device of claim 2, wherein the determination unit determines that a duplicate feed of media has occurred when a media detection sensor that first detects a medium among the multiple media detection sensors detects a medium, and then an overlap detection sensor downstream of the media detection sensor detects an overlap of media, and an overlap detection sensor other than the overlap detection sensor also detects an overlap of media.

4. The medium transport device according to claim 2 , wherein the determination unit determines that the medium is a card medium when only a predetermined number of the overlap detection sensors among the plurality of overlap detection sensors detect an overlap of the medium.

5. A medium conveying device as described in any one of claims 1 to 4, wherein, among the multiple medium detection sensors, a medium detection sensor arranged in the center in a direction perpendicular to the conveying direction is arranged further downstream in the conveying direction than a medium detection sensor arranged on the end side.

6. 6. The medium transport device of claim 5, wherein the overlap detection sensor corresponding to the medium detection sensor arranged in the center is arranged further downstream in the transport direction than the overlap detection sensor corresponding to the medium detection sensor arranged on the end side.

7. A control method for a medium transport device having a separation roller for separating a medium, a plurality of medium detection sensors arranged downstream of the separation roller in a medium transport direction and along a direction perpendicular to the transport direction, and a plurality of overlap detection sensors arranged downstream of each of the medium detection sensors in the transport direction for detecting overlapping of the media, the method comprising the steps of: determining whether the medium is a bound medium based on detection results of the plurality of medium detection sensors and the plurality of overlap detection sensors; If the medium is determined to be a bound medium, stopping the transport of the medium; In the determination, if a media detection sensor that first detects a medium among the plurality of media detection sensors detects the medium, and then an overlap detection sensor downstream of the media detection sensor does not detect an overlap of media, and an overlap detection sensor other than the first overlap detection sensor detects an overlap of media, the medium is determined to be a bound medium. A control method comprising:

8. A control program for a medium transport device having a separation roller for separating a medium, a plurality of medium detection sensors arranged downstream of the separation roller in a medium transport direction and along a direction perpendicular to the transport direction, and a plurality of overlap detection sensors arranged downstream of each of the medium detection sensors in the transport direction for detecting overlapping of the media, the control program comprising: determining whether the medium is a bound medium based on detection results of the plurality of medium detection sensors and the plurality of overlap detection sensors; when the medium is determined to be a bound medium, stopping the transport of the medium; In the determination, if a media detection sensor that first detects a medium among the plurality of media detection sensors detects the medium, and then an overlap detection sensor downstream of the media detection sensor does not detect an overlap of media, and an overlap detection sensor other than the first overlap detection sensor detects an overlap of media, the medium is determined to be a bound medium. A control program comprising:

Images