MEDIUM EXTRACTING DEVICE, CONTROL METHOD, AND CONTROL PROGRAM

Abstract

Provided are a medium ejection device, a control method, and a control program, whereby it is possible to satisfactorily eject a medium while satisfactorily capture an image of the medium. This medium ejection device comprises: an image-capturing unit that captures an image of a medium and generates an input image; an ejection roller that is disposed downstream of the image-capturing unit in the medium ejection direction so as to eject the medium, the image of which has been captured by the image-capturing unit; a sensor that is disposed between the image-capturing unit and the ejection roller so as to detect part of the rear end of the medium; a detection unit that detects the amount of inclination of the medium; a determination unit that, when part of the rear end of the medium has passed through the sensor, determines whether or not the entire rear end of the medium has passed through the image-capturing position by the image-capturing unit on the basis of the amount of inclination; and a control unit that controls the ejection roller on the basis of the determination result by the determination unit.

Description

[Technical field]

[0001] The present disclosure relates to a medium ejection device, a control method, and a control program, and more particularly to a medium ejection device that captures an image of a medium, a control method, and a control program. [Background technology]

[0002] A medium ejection device such as a scanner sequentially transports a plurality of media, captures the images, generates images, and ejects the images onto a ejection tray. In such a medium ejection device, if the media ejected onto the ejection tray are not aligned, the user must align the media. On the other hand, if the media ejection speed is changed in the medium ejection device to align the media to be ejected onto the ejection tray, the interval between the positions at which the images are captured on the media may change, causing distortion in the generated image.

[0003] An original reading device has been disclosed that detects the amount of skew of an original using an original detection sensor, and controls the relationship between the original transport speed by a pair of transport rollers and the original transport speed by a pair of discharge rollers in accordance with the amount of skew (see Patent Document 1).

[0004] An image reading device is disclosed that detects the arrival of an original at a pre-registration sensor to detect the amount of skew of the original being conveyed, and detects the arrival of the original at a discharge sensor to detect the amount of skew of the original being discharged (see Patent Document 2). This image reading device controls to stop the conveying operation and discharge operation when the absolute value of the difference between the two skew amounts is greater than a threshold value. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-331908 A [Patent Document 2] JP 2010-114817 A Summary of the Invention

[0006] A medium ejection device is required to eject a medium in a good condition while capturing an image of the medium in a good condition.

[0007] An object of the medium ejection device, control method, and control program according to the embodiment is to enable a medium to be properly ejected while being properly imaged.

[0008] A medium ejection device according to one aspect of an embodiment includes an imaging unit that captures an image of a medium to generate an input image, an ejection roller that is disposed downstream of the imaging unit in the medium ejection direction and ejects the medium imaged by the imaging unit, a sensor that is disposed between the imaging unit and the ejection roller and detects a portion of the rear end of the medium, a detection unit that detects an amount of tilt of the medium, and a detection unit that, when a portion of the rear end of the medium passes the sensor, determines based on the amount of tilt that the entire rear end of the medium has passed a position imaged by the imaging unit. If this is detected, the rotation speed of the ejection roller is changed. and a control unit that controls the discharge rollers.

[0009] Also, a control method according to one aspect of the embodiment is a control method for a medium ejection device, which includes an imaging unit that captures an image of a medium to generate an input image, an ejection roller that is disposed downstream of the imaging unit in the medium ejection direction ejects the medium imaged by the imaging unit, a sensor that is disposed between the imaging unit and the ejection roller detects a portion of a rear end of the medium and detects an amount of tilt of the medium, and when a portion of the rear end of the medium has passed the sensor, it is determined based on the amount of tilt that the entire rear end of the medium has passed a position imaged by the imaging unit. If this is detected, the rotation speed of the ejection roller is changed. Controls the ejection rollers.

[0010] Also, a control program according to one aspect of the embodiment is a control program for a medium discharge device having an imaging unit that captures an image of a medium to generate an input image, an ejection roller that is disposed downstream of the imaging unit in the medium ejection direction and ejects the medium imaged by the imaging unit, and a sensor that is disposed between the imaging unit and the ejection roller and detects a portion of the rear end of the medium, the control program detecting an amount of tilt of the medium, and determining, when a portion of the rear end of the medium has passed the sensor, based on the amount of tilt, that the entire rear end of the medium has passed a position imaged by the imaging unit. If this is detected, the rotation speed of the ejection roller is changed. The media ejection device controls the ejection rollers. Effect of the Invention

[0011] According to the present embodiment, the medium ejection device, the control method, and the control program are capable of ejecting the medium satisfactorily while capturing an image of the medium satisfactorily.

[0012] 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]

[0013] [Figure 1] 1 is a perspective view showing a medium ejection device 100 according to an embodiment. [Diagram 2] 2 is a diagram for explaining a transport path inside the medium ejection device 100. FIG. [Diagram 3] 5 is a schematic diagram for explaining the arrangement positions of each media sensor. FIG. [Figure 4] 1 is a block diagram showing a schematic configuration of a medium ejection 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] 10 is a flowchart illustrating an example of the operation of a medium reading process. [Figure 7] 10 is a flowchart illustrating an example of the operation of a medium reading process. [Figure 8] 2 is a schematic diagram showing an example of a partial image N. FIG. [Figure 9] 13 is a flowchart showing an example of a portion of the operation of another medium reading process. [Figure 10] 13 is a flowchart showing an example of a portion of the operation of another medium reading process. [Figure 11] 1A and 1B are schematic diagrams for explaining skew correction of a medium. [Figure 12] 13 is a flowchart showing an example of a portion of the operation of another medium reading process. [Figure 13] FIG. 13 is a diagram showing a schematic configuration of another processing circuit 250. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, a medium ejection device, a control method, and a control program according to one aspect of the present disclosure will be described with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to the embodiments, but extends to the inventions described in the claims and their equivalents.

[0015] 1 is a perspective view showing a medium ejection device 100 configured as an image scanner. The medium ejection device 100 conveys a medium, which is an original document, captures an image, and ejects it. The medium is paper, cardboard, a card, a booklet, a passport, or the like. The medium ejection device 100 may be a facsimile, a copier, a multifunction printer (MFP, Multifunction Peripheral), or the like.

[0016] 1, arrow A1 indicates the medium discharge direction, arrow A2 indicates the width direction perpendicular to the medium discharge direction, and arrow A3 indicates the height direction perpendicular to the medium transport path. In the following, upstream refers to the upstream side of the medium discharge direction A1, and downstream refers to the downstream side of the medium discharge direction A1.

[0017] The medium ejection device 100 includes a lower housing 101, an upper housing 102, a placement stand 103, an ejection stand 104, an operation device 105, a display device 106, and the like.

[0018] Upper housing 102 is disposed in a position that covers the top surface of medium ejection device 100, and engages with lower housing 101 by a hinge so that it can be opened and closed when loading media, cleaning the inside of medium ejection device 100, and the like.

[0019] The placement stage 103 engages with the lower housing 101 and places thereon the media to be fed and transported. The ejection stage 104 engages with the upper housing 102 and places thereon the ejected media. Note that the ejection stage 104 may also engage with the lower housing 101.

[0020] 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.

[0021] FIG. 2 is a diagram for explaining a transport path inside medium ejection device 100. As shown in FIG.

[0022] The transport path inside the media ejection device 100 includes a first media sensor 111, a feed roller 112, a separation roller 113, a second media sensor 114, a third media sensor 115, a fourth media sensor 116, a first transport roller 117, a second transport roller 118, an imaging device 119, a fifth media sensor 120, a first ejection roller 121, and a second ejection roller 122, etc.

[0023] The number of each of the feed roller 112, separation roller 113, first conveyor roller 117, second conveyor roller 118, first discharge roller 121 and / or second discharge roller 122 is not limited to one, and may be more than one. In this case, the multiple feed rollers 112, separation rollers 113, first conveyor roller 117, second conveyor roller 118, first discharge roller 121 and / or second discharge roller 122 are arranged at intervals in the width direction A2 perpendicular to the medium discharge direction A1.

[0024] The top surface of lower housing 101 forms lower guide 107a of the medium transport path, and the bottom surface of upper housing 102 forms upper guide 107b of the medium transport path. As shown in Fig. 2, the medium transport path has a so-called straight path mechanism in which the vertical positional relationship between the front and back surfaces of the medium does not change between the state before transport in which the medium is placed on mounting table 103, and the state after ejection in which the medium is placed on ejection table 104. Since the medium transport path has a straight path mechanism, medium ejection device 100 is formed compactly.

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

[0026] The feed roller 112 is provided in the lower housing 101 and feeds the media placed on the mounting table 103 in order from the bottom. The separation roller 113 is provided in the upper housing 102 and disposed opposite the feed roller 112. Note that the feed roller 112 may be provided in the upper housing 102 and the separation roller 113 in the lower housing 101, and the feed roller 112 may feed the media placed on the mounting table 103 in order from the top.

[0027] The first conveyor roller 117 and the second conveyor roller 118 are disposed facing each other downstream of the feed roller 112. The first conveyor roller 117 and the second conveyor roller 118 convey the medium fed by the feed roller 112 and the separation roller 113 to the imaging device 119.

[0028] The imaging device 119 is an example of an imaging section, and includes a first imaging device 119a and a second imaging device 119b that are disposed opposite each other across the medium transport path.

[0029] The first imaging device 119a has a first imaging sensor 119c using a CIS (Contact Image Sensor) of a life-size optical system type having imaging elements using CMOS (Complementary Metal Oxide Semiconductor) linearly arranged in the main scanning direction. The first imaging sensor 119c images the surface of the medium at a first imaging position P1. The first imaging position P1 is an example of a first position, and the surface of the medium is an example of a first surface. The first imaging device 119a also has a lens that forms an image on the imaging element, and an A / D converter that amplifies and analog-to-digital (A / D) converts the electrical signal output from the imaging element. The first imaging device 119a images an area facing the first imaging sensor 119c on the surface of the medium being conveyed at regular intervals, sequentially generates input images, and outputs them. That is, the number of pixels in the vertical direction (sub-scanning direction) of the input image is one, and the number of pixels in the horizontal direction (main scanning direction) is multiple.

[0030] Similarly, the second imaging device 119b has a second imaging sensor 119d using a CIS of a life-size optical system type having imaging elements using CMOS arranged linearly in the main scanning direction. The second imaging sensor 119d images the back surface of the medium at a second imaging position P2 downstream of the first imaging position P1 in the medium discharge direction A1. The second imaging position P2 is an example of a second position, and the back surface of the medium is an example of a second surface. The second imaging position P2 downstream of the first imaging position P1 is an example of an imaging position by the imaging device 119. The second imaging device 119b also has a lens that forms an image on the imaging element, and an A / D converter that amplifies and converts the electrical signal output from the imaging element into an analog / digital (A / D) signal. The second imaging device 119b images an area facing the second imaging sensor 119d on the back surface of the medium being conveyed at regular intervals, sequentially generating and outputting input images.

[0031] The medium ejection 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, a line sensor with a CIS of a life-size optical system type having an imaging element with a CCD (Charge Coupled Device) may be used as the first imaging sensor 119c and / or the second imaging sensor 119d. Also, a line sensor with a reduced optical system type having an imaging element with a CMOS or CCD may be used as the first imaging sensor 119c and / or the second imaging sensor 119d. Also, the first imaging sensor 119c and the second imaging sensor 119d may be arranged so that the second imaging sensor 119d images the back side of the medium at the first imaging position P1, and the first imaging sensor 119c images the front side of the medium at the second imaging position P2 downstream of the first imaging position P1. In that case, the back side of the medium is an example of the first side, and the front side of the medium is an example of the second side.

[0032] The first discharge roller 121 and the second discharge roller 122 are disposed facing each other downstream of the imaging device 119 in the medium discharge direction A1. The first discharge roller 121 and the second discharge roller 122 discharge the medium that has been transported by the first conveyance roller 117 and the second conveyance roller 118 and imaged by the imaging device 119 to the discharge tray 104. The first discharge roller 121 and / or the second discharge roller 122 are an example of a discharge roller. Hereinafter, the first discharge roller 121 and / or the second discharge roller 122 may be collectively referred to as discharge rollers.

[0033] 2, i.e., the medium feeding direction, the medium placed on the placement table 103 is transported between the lower guide 107a and the upper guide 107b in the medium discharge direction A1. The separation roller 113 rotates in the direction of the arrow A5, i.e., the opposite direction to the medium feeding direction, when transporting the medium. When multiple media are placed on the placement table 103, the feed roller 112 and the separation roller 113 function to separate only the media placed on the placement table 103 that is in contact with the feed roller 112. This limits the transport of media other than the separated media (preventing double feeding).

[0034] The medium is fed between the first conveyor roller 117 and the second conveyor roller 118 while being guided by the lower guide 107a and the upper guide 107b. The medium is fed between the first imaging device 119a and the second imaging device 119b as the first conveyor roller 117 and the second conveyor roller 118 rotate in the directions of the arrows A6 and A7, respectively. The medium read by the imaging device 119 is discharged onto the discharge tray 104 as the first discharge roller 121 and the second discharge roller 122 rotate in the directions of the arrows A8 and A9, respectively. The discharge tray 104 holds the media discharged by the first discharge roller 121 and the second discharge roller 122.

[0035] Fig. 3 is a schematic diagram for explaining the arrangement positions of the rollers and the media sensors, Fig. 3 is a schematic diagram of the lower housing 101 in an open state, as viewed from the transport path side.

[0036] In the example shown in FIG. 3, the feed roller 112, the separation roller 113, the first conveyor roller 117, the second conveyor roller 118, the first discharge roller 121, and the second discharge roller 122 are arranged in pairs.

[0037] The second medium sensor 114 and the third medium sensor 115 are an example of a plurality of second sensors. The second medium sensor 114 and the third medium sensor 115 are arranged downstream of the feed roller 112 and the separation roller 113 in the medium discharge direction A1 and upstream of the imaging device 119, and are arranged side by side at intervals in the width direction A2 perpendicular to the medium discharge direction. The second medium sensor 114 and the third medium sensor 115 are arranged such that the distance W in the width direction A2 between the second medium sensor 114 and the third medium sensor 115 is less than the minimum width of the medium supported by the medium discharge device 100. In the example shown in FIG. 3, the second medium sensor 114 and the third medium sensor 115 are arranged upstream of the first conveyor roller 117 and the second conveyor roller 118. Note that the second medium sensor 114 and the third medium sensor 115 may be arranged downstream of the first conveyor roller 117 and the second conveyor roller 118. The second media sensor 114 and the third media sensor 115 detect the leading and trailing ends of the media transported to that position.

[0038] The second medium sensor 114 includes a light emitter and a light receiver provided on one side of the medium transport path, and a light guide member provided at a position facing the light emitter and the light receiver across the medium transport path. The light guide member is a light guide tube such as a U-shaped prism. The light emitter is an LED (Light Emitting Diode) or the like, and irradiates light toward the transport path. On the other hand, the light receiver is a photodiode or the like, and receives the light irradiated by the light emitter and guided by the light guide member. When a medium is present at a position facing the second medium sensor 114, the light irradiated from the light emitter is blocked by the medium, so that the light receiver does not detect the light irradiated from the light emitter. The light receiver generates and outputs a second medium signal whose signal value changes depending on whether a medium is present or not at the position of the second medium sensor 114 based on the intensity of the received light. The second medium signal is an example of an output signal from the second medium sensor 114.

[0039] Similarly, the third medium sensor 115 includes a light emitter and a light receiver provided on one side of the medium transport path, and a light guide member provided at a position facing the light emitter and the light receiver across the medium transport path. The light guide member is a light guide tube such as a U-shaped prism. The light emitter is an LED or the like, and irradiates light toward the transport path. Meanwhile, the light receiver is a photodiode or the like, and receives the light irradiated by the light emitter and guided by the light guide member. Based on the intensity of the received light, the light receiver generates and outputs a third medium signal whose signal value changes depending on whether a medium is present or not at the position of the third medium sensor 115. The third medium signal is an example of an output signal from the third medium sensor 115.

[0040] The fourth medium sensor 116 is disposed downstream of the feed roller 112 and the separation roller 113 in the medium discharge direction A1 and upstream of the imaging device 119. The fourth medium sensor 116 is disposed in the center in the width direction A2 perpendicular to the medium discharge direction, particularly between the two first conveyor rollers 117 and between the two second conveyor rollers 118. In the example shown in FIG. 3, the fourth medium sensor 116 is disposed downstream of the second medium sensor 114 and the third medium sensor 115 and upstream of the first conveyor roller 117 and the second conveyor roller 118. The fourth medium sensor 116 may be disposed in the same position as the second medium sensor 114 and the third medium sensor 115, or upstream of the second medium sensor 114 and the third medium sensor 115 in the medium discharge direction A1. The fourth medium sensor 116 may be disposed downstream of the first conveyor roller 117 and the second conveyor roller 118. The fourth media sensor 116 detects the leading and trailing edges of the media transported to that position.

[0041] The fourth medium sensor 116 includes a light emitter and a light receiver provided on one side of the medium transport path, and a light guide member provided at a position facing the light emitter and the light receiver across the medium transport path. The light guide member is a light guide tube such as a U-shaped prism. The light emitter is an LED or the like, and irradiates light toward the transport path. Meanwhile, the light receiver is a photodiode or the like, and receives the light irradiated by the light emitter and guided by the light guide member. Based on the intensity of the light received, the light receiver generates and outputs a fourth medium signal whose signal value changes depending on whether a medium is present or not at the position of the fourth medium sensor 116.

[0042] The fifth media sensor 120 is an example of a sensor, and is disposed between the imaging device 119 and the first and second discharge rollers 121 and 122. That is, the fifth media sensor 120 is disposed downstream of the imaging device 119 in the medium discharge direction A1 and upstream of the first and second discharge rollers 121 and 122. The fifth media sensor 120 is also disposed in the center in the width direction A2 perpendicular to the medium discharge direction, particularly between the two first discharge rollers 121 and between the two second discharge rollers 122. The fifth media sensor 120 detects the leading and trailing ends of the medium transported to that position.

[0043] The fifth medium sensor 120 includes a light emitter and a light receiver provided on one side of the medium transport path, and a light guide member provided at a position facing the light emitter and the light receiver across the medium transport path. The light guide member is a light guide tube such as a U-shaped prism. The light emitter is an LED or the like, and irradiates light toward the transport path. Meanwhile, the light receiver is a photodiode or the like, and receives the light irradiated by the light emitter and guided by the light guide member. Based on the intensity of the received light, the light receiver generates and outputs a fifth medium signal whose signal value changes depending on whether a medium is present or not at the position of the fifth medium sensor 120.

[0044] A reflective member such as a mirror may be used instead of a light guiding member in second medium sensor 114, third medium sensor 115, fourth medium sensor 116 and / or fifth medium sensor 120. In second medium sensor 114, third medium sensor 115, fourth medium sensor 116 and / or fifth medium sensor 120, the light emitter and light receiver may be provided in positions facing each other across the transport path. Second medium sensor 114, third medium sensor 115, fourth medium sensor 116 and / or fifth medium sensor 120 may detect the presence of the medium using a contact detection sensor or the like that passes a predetermined current when the medium is in contact or when the medium is not in contact.

[0045] FIG. 4 is a block diagram showing a schematic configuration of the medium ejection device 100. As shown in FIG.

[0046] In addition to the components described above, the medium ejection device 100 further includes a motor 131, an interface device 132, a storage device 140, a processing circuit 150, and the like.

[0047] The motor 131 has one or more motors, and rotates the feed roller 112, separation roller 113, first conveyor roller 117, second conveyor roller 118, first discharge roller 121, and second discharge roller 122 to convey the medium in response to a control signal from the processing circuit 150. Note that one of the first conveyor roller 117 and the second conveyor roller 118 may be a driven roller that rotates following the other roller. Also, one of the first discharge roller 121 and the second discharge roller 122 may be a driven roller that rotates following the other roller.

[0048] 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 input images 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 device for transmitting and receiving signals through a wireless communication line in accordance with a predetermined communication protocol may be used. The predetermined communication protocol is, for example, a wireless LAN (Local Area Network). The communication unit may have a wired communication interface device for transmitting and receiving signals through a wired communication line in accordance with a communication protocol such as a wired LAN.

[0049] 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 ejection device 100. The computer programs may be installed in the storage device 140 from a computer-readable portable recording medium using a known setup program or the like. The portable recording medium is, for example, a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), or the like.

[0050] The processing circuit 150 operates based on a program previously stored in the storage device 140. The processing circuit is, for example, a CPU (Central Processing Unit). The processing circuit 150 may be, for example, a DSP (digital signal processor), an LSI (large scale integration), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array).

[0051] The processing circuit 150 is connected to the operation device 105, the display device 106, the first medium sensor 111, the second medium sensor 114, the third medium sensor 115, the fourth medium sensor 116, the imaging device 119, the fifth medium sensor 120, the motor 131, the interface device 132, the storage device 140, and the like, and controls each of these components. The processing circuit 150 performs drive control of the motor 131, image capture control of the imaging device 119, and the like, acquires an input image from the imaging device 119, generates a medium image, and transmits it to the information processing device via the interface device 132. The processing circuit 150 also detects the amount of tilt of the medium based on the input image, and when a part of the rear end of the medium passes the position of the fifth medium sensor 120, determines whether or not the entire rear end of the medium has passed the imaging position of the imaging device 119 based on the amount of tilt. The processing circuit 150 controls the first discharge roller 121 and / or the second discharge roller 122 based on the determination result.

[0052] FIG. 5 is a diagram showing a schematic configuration of the storage device 140 and the processing circuit 150. As shown in FIG.

[0053] 5, the storage device 140 stores a control program 141, a detection program 142, a judgment program 143, a skew judgment program 144, and the like. Each of these programs is a functional module implemented by software that runs on a processor. The processing circuit 150 reads each program stored in the storage device 140 and operates according to the read program. As a result, the processing circuit 150 functions as a control unit 151, a detection unit 152, a judgment unit 153, and a skew judgment unit 154.

[0054] 6 and 7 are flowcharts showing an example of the operation of the medium reading process of the medium ejection device 100. In FIG.

[0055] An example of the operation of the medium reading process of medium ejection device 100 will be described below with reference to the flowcharts shown in Figures 6 and 7. Note that the flow of the operation described below is executed mainly by processing circuit 150 in cooperation with each element of medium ejection device 100 based on a program stored in advance in storage device 140.

[0056] First, the control unit 151 waits until a user inputs an instruction to read a medium using the operation device 105 or an information processing device, and an operation signal instructing the user to read a medium is received from the operation device 105 or the interface device 132 (step S101).

[0057] Next, control unit 151 acquires a first medium signal from first medium sensor 111, and determines whether or not a medium is placed on placement table 103 based on the acquired first medium signal (step S102). If no medium is placed on placement table 103, control unit 151 ends the series of steps.

[0058] On the other hand, when a medium is placed on the placement table 103, the control unit 151 drives the motor 131. The control unit 151 rotates the feed roller 112, the separation roller 113, the first conveyor roller 117, the second conveyor roller 118, the first discharge roller 121 and / or the second discharge roller 122 to convey the medium (step S103).

[0059] Next, control unit 151 waits until the leading edge of the transported medium passes the position of fourth medium sensor 116 (step S104). Control unit 151 periodically acquires a fourth medium signal from fourth medium sensor 116, and determines that the leading edge of the medium has passed the position of fourth medium sensor 116 when the signal value of the fourth medium signal changes from a value indicating that the medium is not present to a value indicating that the medium is present.

[0060] On the other hand, when the leading edge of the transported medium passes the position of the fourth medium sensor 116, the control unit 151 causes the imaging device 119 to start imaging the medium (step S105). After that, the control unit 151 acquires an input image from the imaging device 119 at regular intervals (each time the imaging device 119 generates an input image) and stores it in the storage device 140.

[0061] Next, the control unit 151 waits until a part of the trailing end of the transported medium passes the first imaging position P1 of the first imaging sensor 119c arranged upstream of the second imaging sensor 119d (step S106). The control unit 151 periodically acquires a fourth medium signal from the fourth medium sensor 116, and determines that the trailing end of the medium has passed the position of the fourth medium sensor 116 when the signal value of the fourth medium signal changes from a value indicating the presence of the medium to a value indicating the absence of the medium. The control unit 151 determines that a part of the trailing end of the medium has passed the first imaging position P1 when a first predetermined time has elapsed since the trailing end of the medium passed the position of the fourth medium sensor 116. The first predetermined time is set to a value obtained by adding or subtracting a margin to the time required for the medium to move from the fourth medium sensor 116 to the first imaging position P1. The control unit 151 may determine that a part of the trailing end of the medium has passed the first imaging position P1 when a predetermined time has elapsed since the feeding of the medium started.

[0062] When a part of the rear end of the medium has passed the first imaging position P1, the control unit 151 generates a partial image by combining the input images acquired up to now from the first imaging device 119a (step S107).

[0063] FIG. 8 is a schematic diagram showing an example of the partial image N.

[0064] 8 includes the medium M1 that has been transported tilted. However, because the medium M1 is tilted, a portion of the rear end of the medium M1 is not included in the partial image N. The partial image N is used to calculate the tilt angle (amount of tilt) θ of the medium M1, so it is not necessary for the partial image N to include the entire rear end of the medium M1. The control unit 151 generates the partial image N at a point in time when only a portion of the rear end of the medium M1 is included, thereby enabling the medium discharge device 100 to detect the amount of tilt θ of the medium at an early stage.

[0065] Next, the detection unit 152 detects the amount of tilt θ of the medium from the partial image N (step S108). That is, the detection unit 152 detects the amount of tilt θ of the medium based on the input image captured by the first imaging sensor 119c, whose imaging position is upstream of the second imaging sensor 119d. This allows the detection unit 152 to detect the amount of tilt of the medium at an earlier stage.

[0066] The detection unit 152 first calculates, for each vertical line extending in the vertical direction (sub-scanning direction) within a predetermined range R from the bottom end of the partial image N, the absolute value of the difference in gradation value between the pixels adjacent to each pixel in the vertical direction (hereinafter referred to as adjacent difference value) in each vertical line, starting from the bottom. The predetermined range R is set to a range that certainly includes the rear end of the medium (for example, a range of 1000 pixels). The detection unit 152 detects pixels in each vertical line whose adjacent difference value exceeds a gradation threshold as edge pixels. The gradation value is a luminance value or a color value (R value, G value, or B value), etc. The gradation threshold is set, for example, to a difference in luminance value (for example, 20) that allows a person to visually distinguish the difference in luminance on the image. The detection unit 152 detects the edge pixel located at the lowest position in each vertical line as the bottom edge pixel.

[0067] The detection unit 152 may calculate, as the adjacent difference value, the absolute value of the difference in gradation values ​​between two pixels that are a predetermined distance away from each pixel in the horizontal or vertical direction. The detection unit 152 may also detect edge pixels by comparing the gradation value of each pixel with a threshold. For example, when the gradation value of a specific pixel is less than the threshold and the gradation value of a pixel adjacent to the specific pixel in the horizontal or vertical direction or a pixel that is a predetermined distance away from the specific pixel is equal to or greater than the threshold, the detection unit 152 detects the specific pixel as an edge pixel.

[0068] Next, the detection unit 152 detects a straight line (line segment) from the bottom edge pixels using the least squares method as the bottom edge of the medium. The detection unit 152 may detect the straight line using a Hough transform. Furthermore, when multiple straight lines are detected from the bottom edge pixels, the detection unit 152 may detect the straight line having the longest length in the horizontal direction (main scanning direction) as the bottom edge of the medium. In the example shown in FIG. 8, straight lines C1 and C2 are detected from the bottom edge pixels, and the straight line C2 having the longest length in the horizontal direction (main scanning direction) is detected as the bottom edge of the medium. The detection unit 152 detects the angle θ between the detected straight line (bottom edge of the medium) and the horizontal direction as the amount of inclination of the medium.

[0069] Next, detection unit 152 estimates the amount of positional deviation in the medium discharge direction A1 between end position B1 on the side where progress is delayed at the rear end of the medium and position B2 facing fifth medium sensor 120 (step S109).

[0070] Based on the inclination of the bottom edge of the medium, the detection unit 152 identifies the edge on the left or right edge on the rear edge of the medium that is slower in progress. Similar to the process of step S109, the detection unit 152 detects an edge edge pixel B3 corresponding to the identified edge within a bottom edge line extending in the horizontal direction (main scanning direction) that is located at the bottommost position of the partial image N in the vertical direction (sub-scanning direction) within the partial image. The detection unit 152 calculates adjacent difference values ​​within the bottom edge line in order from the identified edge side, and detects the pixel whose adjacent difference value first exceeds the gradation threshold as the edge edge pixel B3.

[0071] The detection unit 152 calculates the horizontal distance x between the detected end edge pixel B3 and pixel B4 corresponding to the fifth media sensor 120 within the bottom end line. The horizontal position of pixel B4 corresponding to the fifth media sensor 120 within the bottom end line is set in advance based on the positional relationship between the first imaging position P1 of the first imaging sensor 119c and the arrangement position of the fifth media sensor 120. Next, the detection unit 152 calculates (estimates) the vertical positional deviation y on the partial image between end position B1 on the side where the progress of the rear end of the medium is delayed and position B2 facing the fifth media sensor 120 based on the horizontal distance x and the tilt amount θ using the following approximation formula (1): y ≒ x tan θ (1)

[0072] Based on the resolution of the partial image, the detection unit 152 calculates the amount of positional deviation in the medium discharge direction A1 in real space between the end position B1 on the side where the progress of the rear end of the medium is delayed and the position B2 opposite the fifth media sensor 120, which corresponds to the amount of positional deviation y on the partial image.

[0073] Next, determination unit 153 waits until part of the trailing end of the transported medium passes the position of fifth medium sensor 120 (step S201). Determination unit 153 periodically acquires a fifth medium signal from fifth medium sensor 120, and determines that part of the trailing end of the medium has passed the position of fifth medium sensor 120 when the signal value of the fifth medium signal changes from a value indicating the presence of a medium to a value indicating the absence of a medium.

[0074] The determination unit 153 determines whether or not the entire rear end of the medium has passed the imaging position by the imaging device 119 based on the amount of tilt θ of the medium detected by the detection unit 152 when part of the rear end of the medium has passed the position of the fifth medium sensor 120 (step S202). The determination unit 153 determines whether or not the entire rear end of the medium has passed the second imaging position P2 of the second imaging sensor 119d, which is located downstream of the first imaging position P1 of the first imaging sensor 119c, as the imaging position by the imaging device 119. This allows the determination unit 153 to determine whether or not the entire rear end of the medium has passed both the imaging position by the first imaging sensor 119c and the imaging position by the second imaging sensor 119d.

[0075] The determination unit 153 determines whether the amount of positional deviation in the medium discharge direction A1 between the end position B1 on the side where the trailing end of the medium is lagging behind, detected by the detection unit 152, and the position B2 facing the fifth medium sensor 120, is less than a predetermined distance L1. The predetermined distance L1 is set to the distance between the position of the fifth medium sensor 120 in the medium discharge direction A1 and the second imaging position P2 of the second imaging sensor 119d, which is located downstream of the first imaging position P1 of the first imaging sensor 119c (see FIG. 3). In other words, the determination unit 153 determines whether the end on the side where the trailing end of the medium is lagging behind has passed the second imaging position P2.

[0076] When the amount of positional deviation of the trailing end of the medium is less than the predetermined distance L1, the determination unit 153 determines that the entire trailing end of the medium has passed through the second imaging position P2 of the second imaging sensor 119d, and has passed through the imaging position by the imaging device 119. On the other hand, when the amount of positional deviation of the trailing end of the medium is equal to or greater than the predetermined distance L1, the determination unit 153 determines that the entire trailing end of the medium has not passed through the second imaging position P2 of the second imaging sensor 119d, and has not passed through the imaging position by the imaging device 119.

[0077] When it is determined that the entire rear end of the medium has passed the imaging position when a part of the rear end of the medium has passed the fifth medium sensor 120, the control unit 151 controls the discharge rollers to change the rotation speed of the discharge rollers (step S203). Even if a change is made to the movement of the medium after the entire rear end of the medium has passed the imaging position of the imaging device 119, the medium included in the medium image in which the medium is captured is not affected. When the entire rear end of the medium has passed the imaging position of the imaging device 119, the control unit 151 appropriately changes the rotation speed of the discharge rollers, thereby suppressing distortion of the medium in the medium image and allowing each medium loaded on the discharge tray 104 to be properly aligned. Therefore, scattering of the media on the discharge tray 104 is suppressed, and the user does not need to align the scattered media, and the medium discharge device 100 can improve the convenience of the user.

[0078] For example, if it is determined that the entire rear end of the medium has passed the imaging position by imaging device 119 when part of the rear end of the medium has passed fifth medium sensor 120, control unit 151 reduces the rotation speed of the discharge rollers. This allows control unit 151 to increase the medium transport speed until the medium is imaged, and reduce the transport speed only when the medium is discharged. Therefore, control unit 151 can reduce the total time required for the medium reading process, and prevent the media from being discharged too quickly and scattering.

[0079] On the other hand, if it is determined that the entire rear end of the medium has not passed the imaging position when a portion of the rear end of the medium has passed the fifth medium sensor 120, the control unit 151 controls the discharge rollers so as not to change the rotation speed of the discharge rollers (step S204). If a change is made to the movement of the medium when the entire rear end of the medium has not passed the imaging position captured by the imaging device 119, an effect occurs on the medium included in the medium image captured of the medium. If the entire rear end of the medium has passed the imaging position captured by the imaging device 119, the control unit 151 can suppress distortion of the medium in the medium image by not changing the rotation speed of each discharge roller.

[0080] In this way, the control unit 151 controls the first discharge rollers 121 and / or the second discharge rollers 122 based on the determination result by the determination unit 153. This allows the control unit 151 to properly discharge the medium while properly capturing an image of the medium.

[0081] Next, control unit 151 waits until the entire rear end of the medium has passed the position imaged by imaging device 119 (step S205). Control unit 151 determines that the entire rear end of the medium has passed the position imaged by imaging device 119 when a second predetermined time has elapsed since the rear end of the medium passed the position of fifth medium sensor 120. The second predetermined time is set to a margin time that takes into account the amount of tilt of the medium that medium ejection device 100 tolerates. Note that if determination unit 153 determines in step S202 that the entire rear end of the medium has passed the position imaged by imaging device 119, control unit 151 determines that the entire rear end of the medium has already passed the position imaged by imaging device 119.

[0082] Next, the control unit 151 generates a media image from the imaging device 119 by combining the input images acquired from the imaging device 119 up to now, and outputs the generated media image by transmitting it to the information processing device via the interface device 132 (step S206). The media image is an example of an image based on an input image.

[0083] Next, control unit 151 determines whether or not a medium remains on mounting table 103 based on the first medium signal received from first medium sensor 111 (step S207). If a medium remains on mounting table 103, control unit 151 returns the process to step S104, and repeats the processes of steps S104 to S109 and S201 to S207.

[0084] On the other hand, if no media remain on the placement table 103, the control unit 151 stops the motor 131. As a result, the control unit 151 stops the feed roller 112, the separation roller 113, the first conveyor roller 117, the second conveyor roller 118, the first discharge roller 121, and the second discharge roller 122 (step S208), and the series of steps ends.

[0085] Note that the control unit 151 may determine that a medium jam has occurred and execute abnormality processing if the leading edge or trailing edge of the medium does not pass the position of the fourth medium sensor 116 or the position of the fifth medium sensor 120 even after a predetermined time has elapsed since the start of feeding of the medium. As abnormality processing, the control unit 151 stops the motor 131 and stops the feeding and discharging of the medium by the feeding roller 112, the separation roller 113, the first conveying roller 117, the second conveying roller 118, the first discharge roller 121, and the second discharge roller 122. As abnormality processing, the control unit 151 may notify the user by displaying information indicating that a medium jam has occurred on the display device 106 or by transmitting the information to the information processing device via the interface device 132.

[0086] As described above in detail, when part of the rear end of the medium passes a predetermined position, the medium ejection device 100 determines whether or not the entire rear end of the medium has passed the imaging position based on the amount of tilt of the medium, and if it has passed the imaging position, reduces the ejection speed. This enables the medium ejection device 100 to eject the medium well while capturing a good image of the medium.

[0087] Furthermore, medium ejection device 100 can easily determine whether or not the ejection speed can be changed, and can capture an image of a medium and eject it satisfactorily while suppressing an increase in the processing load in the medium reading process. Furthermore, medium ejection device 100 has a compact housing with a straight path mechanism, and can capture an image of a medium and eject it satisfactorily.

[0088] FIG. 9 is a flowchart showing an example of a portion of the operation of a medium reading process of a medium ejection device according to another embodiment.

[0089] The flowchart shown in Fig. 9 is executed in place of the flowchart shown in Fig. 7. The processes of steps S301 to S302, S307 to S308, and S311 to S312 in Fig. 9 are similar to the processes of steps S201 to S202, S205 to S206, and S207 to S208 in Fig. 7, so their explanation will be omitted. Only the processes of steps S303 to S306 and S309 to S310 will be explained below.

[0090] If it is determined in step S302 that the entire trailing edge of the medium has passed the imaging position when part of the trailing edge of the medium has passed the fifth medium sensor 120, the control unit 151 controls the discharge rollers to change the rotation speed of the discharge rollers (step S303). Similar to the process of step S203, the control unit 151 reduces the rotation speed of the discharge rollers.

[0091] Next, the control unit 151 sets the image processing flag to OFF (step S304). The image processing flag is a flag that indicates whether or not image processing is to be performed on the input image.

[0092] On the other hand, if it is determined that the entire trailing edge of the medium has not passed the imaging position when part of the trailing edge of the medium has passed the fifth medium sensor 120, the control unit 151 also controls the discharge rollers to change the rotation speed of the discharge rollers (step S305). Similar to the process of step S303, the control unit 151 reduces the rotation speed of the discharge rollers.

[0093] Next, the control unit 151 sets the image processing flag to ON (step S306).

[0094] In step S309, the control unit 151 determines whether the image processing flag is set to ON or OFF (step S309). If the image processing flag is set to OFF, the control unit 151 shifts the process to step S311 without executing any particular process.

[0095] On the other hand, when the image processing flag is set to ON, the control unit 151 executes image processing on the medium image (step S310). This allows the control unit 151 to correct medium distortion that occurs in the medium image while changing the medium transport speed during medium imaging. Therefore, the control unit 151 can appropriately correct medium distortion that occurs in the medium image while suppressing scattering of the medium on the discharge tray 104, and obtain a good medium image.

[0096] The control unit 151 executes a thinning process on the medium image. The control unit 151 executes a thinning process in the sub-scanning direction on the area captured in the medium image after the speed change, using known interpolation processes such as nearest neighbor interpolation, bilinear interpolation, and bicubic interpolation. In step S305, since the medium conveying speed is reduced, the interval between each position in the medium captured by the imaging device 119 is shortened. Therefore, in the medium image, the medium is captured in a state in which it is elongated in the vertical direction (sub-scanning direction). The control unit 151 executes a thinning process so that the number of pixels in the sub-scanning direction of the area captured in the medium image after the speed change matches the number of pixels in the sub-scanning direction when the speed is not changed. In this way, the control unit 151 can appropriately correct the elongation of the medium that occurs in the medium image and obtain a good medium image.

[0097] In this way, when it is determined that the entire rear end of the medium has passed the imaging position when a part of the rear end of the medium has passed the fifth medium sensor 120, the control unit 151 executes image processing on the medium image while controlling the discharge rollers to change the rotation speed of the discharge rollers. When it is determined that the entire rear end of the medium has passed the imaging position when a part of the rear end of the medium has passed the fifth medium sensor 120, the control unit 151 executes thinning processing on the medium image while reducing the rotation speed of the discharge rollers. This allows the control unit 151 to properly image the medium and properly discharge it even if the medium is transported tilted.

[0098] As described above in detail, the medium ejection device 100 is now capable of ejecting the medium well while capturing a good image of the medium, even when the rotational speed of the ejection roller is reduced when the entire rear end of the medium has not passed the imaging position.

[0099] FIG. 10 is a flowchart showing an example of a portion of the operation of a medium reading process of a medium ejection device according to yet another embodiment.

[0100] The flowchart shown in Fig. 10 is executed in place of the flowchart shown in Fig. 7. The processes of steps S402 to S403 and S406 to S409 in Fig. 10 are similar to the processes of steps S201 to S202 and S205 to S208 in Fig. 7, and therefore will not be described below. Only the processes of steps S401 and S404 to S405 will be described below.

[0101] In this embodiment, a plurality of first discharge rollers 121 and a plurality of second discharge rollers 122 are provided and arranged at intervals in the width direction A2. The plurality of first discharge rollers 121 and / or the plurality of second discharge rollers 122 are provided so as to rotate independently to discharge the medium. For example, the plurality of first discharge rollers 121 and / or the plurality of second discharge rollers 122 are provided so as to be driven by separate motors.

[0102] In step S401, the skew determination unit 154 determines whether or not medium skew has occurred based on the amount of tilt θ of the medium detected by the detection unit 152 (step S401). For example, the skew determination unit 154 determines that medium skew has occurred when the amount of tilt θ is equal to or greater than the tilt threshold, and determines that medium skew has not occurred when the amount of tilt θ is less than the tilt threshold. The tilt threshold is preset, through prior experiments, to the minimum amount of tilt (e.g., 3°) at which a medium jam will occur if the medium tilt is not corrected.

[0103] If the skew determining unit 154 determines that the medium is not skewed, it skips steps S402 to S405 and proceeds to step S406. On the other hand, if the skew determining unit 154 determines that the medium is skewed, it proceeds to step S402.

[0104] If it is determined in step S403 that the entire trailing edge of the medium has passed the imaging position when part of the trailing edge of the medium has passed the fifth media sensor 120, the control unit 151 controls the discharge rollers to change the rotation speed of the discharge rollers (step S404). The control unit 151 controls the discharge rollers to correct the skew (tilt) of the medium. The control unit 151 corrects the skew of the medium by making the circumferential speeds of the multiple first discharge rollers 121 different from each other and / or by making the circumferential speeds of the multiple second discharge rollers 122 different from each other. The control unit 151 sets each circumferential speed so that the circumferential speed of the discharge roller located on the side where the medium is lagging behind is greater than the circumferential speed of the discharge roller located on the side where the medium is leading.

[0105] Fig. 11 is a schematic diagram for explaining skew correction of a medium, showing the lower housing 101 viewed from the transport path side in a state in which the medium M2 is being transported tilted.

[0106] 11, the medium M2 is inclined so that the left end of the trailing edge leads and the right end lags. In this case, the control unit 151 sets the circumferential speeds of the first discharge rollers 121 on the right side so that the circumferential speed of the first discharge rollers 121 on the left side is higher.

[0107] For example, the control unit 151 sets the peripheral speed of the discharge roller located on the side where the progress of the medium is delayed to a speed higher (faster) than the reference speed, and sets the peripheral speed of the discharge roller located on the leading side to the reference speed. The control unit 151 may set the peripheral speed of the discharge roller located on the side where the progress of the medium is delayed to the reference speed, and set the peripheral speed of the discharge roller located on the leading side to a speed lower (slower) than the reference speed. The control unit 151 may also set the peripheral speed of the discharge roller located on the side where the progress of the medium is delayed to a speed higher (faster) than the reference speed, and set the peripheral speed of the discharge roller located on the leading side to a speed lower (slower) than the reference speed. As a result, the medium rotates around the discharge roller located on the leading side, and the skew of the medium is eliminated. The control unit 151 also returns the peripheral speed of each discharge roller to the reference speed after a predetermined time has elapsed since starting to correct the skew of the medium.

[0108] As shown in Figure 11, when the medium M2 is transported at an angle, the positional deviation Y in the medium discharge direction A1 of the rear end of the medium M2 at the center positions D1 and D2 in the width direction A2 of the two discharge rollers is calculated using the following equation (2). Y = X tan θ (2) Here, X is the distance between the center positions D1 and D2 of the two discharge rollers in the width direction A2, and θ is the inclination angle (amount of inclination) of the rear end of the medium M2.

[0109] In order to have the rear end of the lagging medium reach the center position of the lagging discharge roller in the medium discharge direction A1 after a predetermined time t, the peripheral speed v1 of the lagging discharge roller needs to be set as shown in the following equation (3). v1=(L2+Y / 2) / t (3) Here, L2 is the distance between the fifth media sensor 120 and the center position of the discharge rollers in the media discharge direction A1.

[0110] On the other hand, in order to have the rear end of the leading side reach the center position of the leading side discharge roller in the media discharge direction A1 after a predetermined time t, the peripheral speed v2 of the leading side discharge roller needs to be set as shown in the following equation (4). v2=(L2-Y / 2) / t (4)

[0111] Therefore, the medium discharge device 100 can appropriately correct the medium skew by setting the peripheral speed v1 of the lagging discharge roller and the peripheral speed v2 of the leading discharge roller to satisfy the following equation (5). v2 / v1=(L2-Y / 2) / (L2+Y / 2) (5)

[0112] On the other hand, if it is determined that the entire trailing edge of the medium has not passed the imaging position when part of the trailing edge of the medium has passed the fifth media sensor 120, control unit 151 does not correct the skew of the medium (step S405).

[0113] That is, when it is determined that medium skew has occurred and it is determined that the entire trailing end of the medium has passed the imaging position when a part of the trailing end of the medium has passed the fifth medium sensor 120, the control unit 151 controls the discharge rollers to correct the medium skew. On the other hand, when it is determined that medium skew has occurred and it is determined that the entire trailing end of the medium has not passed the imaging position when a part of the trailing end of the medium has passed the fifth medium sensor 120, the control unit 151 does not correct the medium skew. This allows the control unit 151 to properly image the medium and properly discharge it, even if the medium is transported tilted.

[0114] In addition, when it is determined that the entire rear end of the medium has passed the imaging position when a part of the rear end of the medium has passed the fifth medium sensor 120, the control unit 151 may correct the skew of the medium and reduce the rotation speed of the discharge roller. In this case, in step S404, the control unit 151 completes the correction of the skew of the medium before the discharge roller reaches the center position in the medium discharge direction A1, and then reduces the rotation speed of the discharge roller. For example, the control unit 151 corrects the skew of the medium until the medium reaches the center position between the fifth medium sensor 120 and the center position of the discharge roller in the medium discharge direction A1, and then reduces the rotation speed of the discharge roller. In this case, the peripheral speed v1 of the lagging discharge roller and the peripheral speed v2 of the leading discharge roller need to be set as shown in the following formulas (6) and (7) instead of the above formulas (3) and (4). v1=(L2 / 2+Y / 2) / t (6) v2=(L2 / 2-Y / 2) / t (7)

[0115] Therefore, the peripheral speed v1 of the lagging discharge roller and the peripheral speed v2 of the leading discharge roller are set so as to satisfy the following formula (8) instead of the above formula (5). v2 / v1=(L2-Y) / (L2+Y) (8)

[0116] Furthermore, the skew determination unit 154 may determine that no medium skew has occurred if the positional deviation amount Y is less than the distance L1 between the position of the fifth medium sensor 120 and the second imaging position P2 of the second imaging sensor 119d. In this case, the control unit 151 does not execute correction of the medium skew if the positional deviation amount Y is less than the distance L1.

[0117] Furthermore, in a state where it is determined that the medium skew has occurred, if it is determined that the entire rear end of the medium has not passed the imaging position when a part of the rear end of the medium has passed the fifth medium sensor 120, the control unit 151 may execute image processing on the medium image while correcting the medium skew. In this case, in step S404, the control unit 151 sets the image processing flag to OFF. Meanwhile, in step S405, the control unit 151 sets the image processing flag to ON while correcting the medium skew in the same manner as the processing in step S404. In step S407, if the image processing flag is set to ON, the control unit 151 executes image processing on the medium image. The control unit 151 uses a known image processing technique to execute conversion processing on the area captured in the medium image after the speed change so that the medium included in the medium image becomes rectangular.

[0118] As described above in detail, the medium ejection device 100 performs skew correction when the entire rear end of the medium has passed the imaging position when a part of the rear end of the medium has passed the predetermined position. In this case as well, the medium ejection device 100 is able to properly image the medium and properly eject it.

[0119] FIG. 12 is a flowchart showing an example of a portion of the operation of a medium reading process of a medium ejection device according to yet another embodiment.

[0120] The flowchart shown in Fig. 12 is executed instead of the flowchart shown in Fig. 6. The processes of steps S501 to S505 in Fig. 12 are similar to the processes of steps S101 to S105 in Fig. 6, and therefore will not be described. Only the processes of steps S506 to S508 will be described below.

[0121] In step S506, control unit 151 waits until the trailing end of the transported medium passes both the position of second medium sensor 114 and the position of third medium sensor 115 (step S506). Control unit 151 periodically acquires a second medium signal from second medium sensor 114, and when the signal value of the second medium signal changes from a value indicating the presence of a medium to a value indicating the absence of a medium, determines that the trailing end of the medium has passed the position of second medium sensor 114. Similarly, control unit 151 periodically acquires a third medium signal from third medium sensor 115, and when the signal value of the third medium signal changes from a value indicating the presence of a medium to a value indicating the absence of a medium, determines that the trailing end of the medium has passed the position of third medium sensor 115.

[0122] Next, detection unit 152 detects the amount of tilt θ of the medium based on the timing when the rear end of the transported medium passes the position of second medium sensor 114 and the position of third medium sensor 115 (step S507). Detection unit 152 calculates the amount of tilt θ of the medium by the following equation (9). θ=tan -1 (Y2 / W) (9) Here, Y2 is the distance that the trailing end of the medium moves from when it passes one of the positions of the second medium sensor 114 and the third medium sensor 115 until it passes the other. Distance Y2 is calculated by multiplying the time that elapses from when the trailing end of the medium passes one of the positions of the second medium sensor 114 and the third medium sensor 115 until it passes the other by the transport speed of the medium. W is the distance in the width direction A2 between the second medium sensor 114 and the third medium sensor 115.

[0123] In this way, detection unit 152 detects the amount of tilt θ of the medium based on the second medium signal from second medium sensor 114 and the third medium signal from third medium sensor 115. By utilizing second medium sensor 114 and third medium sensor 115, which are disposed upstream of imaging device 119, detection unit 152 can detect the amount of tilt of the medium at an earlier stage.

[0124] Next, detection unit 152 estimates the amount of positional deviation in the medium discharge direction A1 between end position B1 on the side where progress is delayed at the rear end of the medium and position B2 facing fifth medium sensor 120 (step S508).

[0125] Detection unit 152 identifies the left or right edge of the medium, which is the end that is slower at the rear end of the medium, based on the timing when the rear end of the medium passes the position of second medium sensor 114 and the timing when it passes the position of third medium sensor 115. Detection unit 152 calculates adjacent difference values ​​in the latest input image, starting from the identified end side, and detects the pixel whose adjacent difference value first exceeds the gradation threshold as the end edge pixel corresponding to the identified end.

[0126] The detection unit 152 calculates the horizontal distance between the detected end edge pixel and the pixel corresponding to the fifth media sensor 120 in the input image. The horizontal position of the pixel corresponding to the fifth media sensor 120 in the partial image is set in advance based on the positional relationship between the first imaging position P1 of the first imaging sensor 119c and the arrangement position of the fifth media sensor 120. The detection unit 152 calculates the distance x' in the width direction A2 in real space between the end position on the side where the progress of the rear end of the medium is delayed and the position facing the fifth media sensor 120, which corresponds to the horizontal distance on the input image, based on the resolution of the input image. Next, the detection unit 152 calculates (estimates) the vertical positional deviation amount y' on the partial image between the end position B1 on the side where the progress of the rear end of the medium is delayed and the position B2 facing the fifth media sensor 120, based on the distance x' and the tilt amount θ, using the following approximation formula (10). y'≒x'·tan θ (10)

[0127] Alternatively, medium ejection device 100 may arrange multiple media sensors along the width direction A2 and identify the end of the rear end of the transported medium in the width direction A2 based on the medium detection signals from each media sensor. Alternatively, medium ejection device 100 may consider the position through which the end of the medium in the width direction A2 passes when a medium of the maximum size supported by medium ejection device 100 is transported without tilting as the end of the rear end of the medium in the width direction A2.

[0128] As described above in detail, the medium ejection device 100 is now able to eject the medium well while capturing a good image of the medium, even when detecting the amount of tilt of the medium based on the second medium signal from the second medium sensor 114 and the third medium signal from the third medium sensor 115.

[0129] 13 is a diagram showing a schematic configuration of a processing circuit 250 in a medium ejection device according to another embodiment. The processing circuit 250 is used in place of the processing circuit 150 of the medium ejection device 100, and executes media reading processing and the like in place of the processing circuit 150. The processing circuit 250 has a control circuit 251, a detection circuit 252, a determination circuit 253, a skew determination circuit 254, and the like. Each of these components may be formed from an independent integrated circuit, microprocessor, firmware, and the like.

[0130] The control circuit 251 is an example of a control unit, and has the same functions as the control unit 151. The control circuit 251 receives an operation signal from the operation device 105 or the interface device 132, a first medium signal from the first medium sensor 111, and a fourth medium signal from the fourth medium sensor 116. The control circuit 251 controls the motor 131 based on each piece of information received, and also acquires an input image from the imaging device 119 and stores it in the storage device 140. The control circuit 251 generates a partial image from the input image and stores it in the storage device 140, and also generates a medium image from the input image and outputs it to the interface device 132. The control circuit 251 also reads out from the storage device 140 the determination result of whether or not the entire rear end of the medium has passed the imaging position and / or the determination result of the skew of the medium, and controls the motor 131 to control the discharge rollers based on the read determination result.

[0131] Detection circuit 252 is an example of a detection unit, and has the same function as detection unit 152. Detection circuit 252 receives a second medium signal from second medium sensor 114, a third medium signal from third medium sensor 115, and a fourth medium signal from fourth medium sensor 116, and reads out a partial image or an input image from storage device 140. Detection circuit 252 detects the amount of tilt and misalignment of the medium from each piece of acquired information, and stores the detection results in storage device 140.

[0132] Determination circuit 253 is an example of a determination unit, and has the same function as determination unit 153. Determination circuit 253 receives a fifth medium signal from fifth medium sensor 120, and reads out the detection results of the amount of tilt and misalignment of the medium from storage device 140. Based on the acquired information, determination circuit 253 determines whether the entire rear end of the medium has passed the imaging position, and stores the determination result in storage device 140.

[0133] The skew determination circuit 254 is an example of a skew determination unit, and has the same function as the skew determination unit 154. The skew determination circuit 254 reads out the detection results of the amount of tilt and misalignment of the medium from the storage device 140, determines whether or not a skew of the medium has occurred based on the read detection results, and stores the determination result in the storage device 140.

[0134] As described above in detail, even when the processing circuit 250 is used, the medium ejection device is able to eject the medium satisfactorily while capturing a good image of the medium. [Explanation of symbols]

[0135] 100 medium discharge device, 114 second medium sensor, 115 third medium sensor, 119 imaging device, 119c first imaging sensor, 119d second imaging sensor, 120 fifth medium sensor, 121 first discharge roller, 122 second discharge roller, 151 control unit, 152 detection unit, 153 determination unit, 154 skew determination unit

Claims

1. an imaging unit that captures an image of a medium to generate an input image; a discharge roller disposed downstream of the imaging unit in a medium discharge direction, for discharging the medium imaged by the imaging unit; a sensor disposed between the imaging unit and the discharge roller for detecting a portion of a trailing edge of the medium; a detection unit that detects the amount of tilt of the medium; a control unit that controls the discharge rollers to change a rotation speed of the discharge rollers when it is detected that the entire trailing edge of the medium has passed an image capturing position by the imaging unit based on the amount of tilt when a part of the trailing edge of the medium has passed the sensor; A medium ejection device comprising:

2. The medium discharge device of claim 1, wherein when a portion of the rear end of the medium passes the sensor but it is not detected that the entire rear end of the medium has passed the imaging position, the control unit controls the discharge roller so as not to change the rotation speed of the discharge roller, or performs image processing on an image based on the input image while controlling the discharge roller so as to change the rotation speed of the discharge roller.

3. The control unit is When it is detected that the entire trailing edge of the medium has passed the imaging position when a part of the trailing edge of the medium has passed the sensor, the rotation speed of the discharge roller is reduced; A medium ejection device as described in claim 1 or 2, wherein if it is not detected that the entire rear end of the medium has passed the imaging position when a portion of the rear end of the medium has passed the sensor, the rotation speed of the ejection roller is not changed, or the rotation speed of the ejection roller is reduced while a thinning process is performed on an image based on the input image.

4. The discharge rollers are arranged at intervals in a direction perpendicular to the medium discharge direction, The method further includes a skew determination unit that determines whether or not a skew of the medium has occurred, The control unit, in a state where it is determined that a skew of the medium has occurred, when it is detected that the entire trailing edge of the medium has passed the imaging position when a part of the trailing edge of the medium has passed the sensor, controlling the discharge rollers to correct a skew of the medium; A media ejection device as described in any one of claims 1 to 3, which does not correct media skew if it is not detected that the entire trailing end of the media has passed the imaging position when a portion of the trailing end of the media has passed the sensor.

5. the imaging unit includes a first imaging sensor that images a first surface of a medium at a first position, and a second imaging sensor that images a second surface of the medium at a second position downstream of the first position in a medium discharge direction; the imaging position is the second position, 5. The medium ejection device according to claim 1, wherein the detection section detects the amount of tilt based on an image captured by the first image sensor.

6. a plurality of second sensors arranged upstream of the imaging unit in the medium ejection direction and spaced apart in a direction perpendicular to the medium ejection direction, for detecting a rear end of the medium; 5. The medium ejection device according to claim 1, wherein the detection section detects the amount of tilt based on output signals from the plurality of second sensors.

7. A method for controlling a medium ejection device, comprising: An imaging unit captures an image of a medium to generate an input image; a discharge roller disposed downstream of the imaging unit in a medium discharge direction, the medium imaged by the imaging unit being discharged; a sensor disposed between the imaging unit and the discharge roller detects a portion of the trailing edge of the medium; Detect the amount of media tilt, when a part of the rear end of the medium passes the sensor, if it is detected based on the amount of tilt that the entire rear end of the medium has passed the image capturing position by the image capturing unit, controlling the discharge rollers to change the rotation speed of the discharge rollers. A control method comprising:

8. A control program for a medium ejection device having an imaging unit that captures an image of a medium to generate an input image, an ejection roller that is disposed downstream of the imaging unit in a medium ejection direction and ejects the medium imaged by the imaging unit, and a sensor that is disposed between the imaging unit and the ejection roller to detect a portion of a rear end of the medium, Detect the amount of media tilt, when a part of the rear end of the medium passes the sensor, if it is detected based on the amount of tilt that the entire rear end of the medium has passed the image capturing position by the image capturing unit, controlling the discharge rollers to change the rotation speed of the discharge rollers. A control program for causing the medium ejection device to execute the above steps.

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