Medium-discharge device, medium-discharge method, and control program

Abstract

To provide a medium-discharge device capable of excellently discharging a medium while excellently subjecting the medium to predetermined processing, and to provide a medium-discharge method and a control program therefor.SOLUTION: A medium-discharge device comprises: a conveyance roller for conveying a medium; a processing part for subjecting the medium conveyed by the conveyance roller to predetermined processing; a discharge roller disposed downstream of the processing part in a medium conveyance direction for discharging the medium subjected to the processing by the processing part; a motor for driving the conveyance roller and the discharge roller; a medium detection part for detecting the medium, that is arranged between the conveyance roller and the processing part; a skew amount detection part for detecting a skew amount of the medium; and a control part for controlling the discharge roller before a rear end of the medium passes through the discharge roller, based on a detection result obtained by the medium detection part, and the skew amount.SELECTED DRAWING: Figure 10

Description

[Technical Field]

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

[0002] A media ejection device, such as a scanner or printer, sequentially transports multiple media, performs a predetermined process, such as capturing an image or forming an image on the media, and ejects the media onto an ejection tray. In such a media ejection device, if the media ejected onto the ejection tray are not aligned, the user must align the media. However, if the media ejection speed is changed in order to align the media being ejected onto the ejection tray, the spacing between the positions where images are captured or formed on the media may change, potentially resulting in distortion of the image captured on the media or the image formed on the media.

[0003] A document reading device is disclosed that detects the amount of skew of a document using a document detection sensor and controls the relationship between the document transport speed by a pair of transport rollers and the document transport speed by a pair of discharge rollers according to the amount of skew (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-331908 Summary of the Invention [Problem to be solved by the invention]

[0005] A medium ejection device is required to properly eject a medium while properly performing a predetermined process on the medium.

[0006] An object of the present invention is to provide a medium ejection device, a medium ejection method, and a control program that are capable of successfully executing a predetermined process on a medium while successfully ejecting the medium. [Means for solving the problem]

[0007] A media discharge device according to one aspect of the present invention comprises a transport roller for transporting a medium, a processing unit that performs a predetermined process on the medium transported by the transport roller, a discharge roller that is arranged downstream of the processing unit in the medium transport direction and discharges the medium processed by the processing unit, a motor that drives the transport roller and the discharge roller, a media detection unit that is arranged between the transport roller and the processing unit and detects the medium, a skew amount detection unit that detects the amount of skew of the medium, and a control unit that controls the discharge roller before the rear end of the medium passes the discharge roller based on the detection result by the media detection unit and the skew amount.

[0008] A media discharge method according to one aspect of the present invention includes: transporting a medium using a transport roller; performing a predetermined process on the medium transported by the transport roller using a processing unit; discharging the medium processed by the processing unit using a discharge roller located downstream of the processing unit in the media transport direction; driving the transport roller and discharge roller using a motor; detecting the medium using a media detection unit located between the transport roller and the processing unit and detecting the amount of skew of the medium; and controlling the discharge roller before the rear end of the medium passes through the discharge roller based on the detection result of the medium and the amount of skew.

[0009] A control program according to one aspect of the present invention is a control program for a media discharge device having a transport roller for transporting a medium, a processing unit for performing a predetermined process on the medium transported by the transport roller, a discharge roller arranged downstream of the processing unit in the medium transport direction for discharging the medium processed by the processing unit, a motor for driving the transport roller and the discharge roller, and a media detection unit arranged between the transport roller and the processing unit for detecting the medium, and causes the media discharge device to detect the amount of skew of the medium and, based on the detection result of the medium and the amount of skew, control the discharge roller before the rear end of the medium passes the discharge roller. [Effects of the Invention]

[0010] According to the present invention, the medium ejection device, medium ejection method, and control program are capable of properly ejecting a medium while properly executing a predetermined process on the medium. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a perspective view showing a medium ejection device according to the embodiment. [Figure 2] 3A and 3B are diagrams illustrating a transport path inside the medium ejection device. [Figure 3] 3 is a schematic diagram for explaining the arrangement positions of each medium sensor. FIG. [Figure 4] FIG. 2 is a block diagram showing a schematic configuration of a medium ejection device. [Figure 5] FIG. 2 is a diagram showing a schematic configuration of a storage device and a processing circuit. [Figure 6] 10 is a flowchart illustrating an example of the operation of a medium transport process. [Figure 7] 10 is a flowchart illustrating an example of the operation of a medium transport process. [Figure 8] 10 is a graph illustrating a change in speed of each roller. [Figure 9] 10 is a graph illustrating a change in speed of each roller. [Figure 10] 10 is a flowchart illustrating an example of a portion of the operation of a discharge control process. [Figure 11] 10 is a graph illustrating a change in speed of each roller. [Figure 12] 10 is a graph illustrating a change in speed of each roller. [Figure 13] 10A and 10B are diagrams illustrating a transport path inside another medium ejection device. [Figure 14] FIG. 10 is a diagram showing a schematic configuration of another processing circuit. DETAILED DESCRIPTION OF THE INVENTION

[0012] The following describes a medium ejection device, a medium ejection method, and a control program according to one aspect of the present invention, with reference to the drawings. However, please note that the technical scope of the present invention is not limited to the embodiments, but extends to the inventions set forth in the claims and their equivalents.

[0013] FIG. 1 is a perspective view showing a medium ejection device configured as an image scanner.

[0014] The medium ejection device 100 transports, captures an image of, and ejects a medium that is an original. The medium may be paper, cardboard, a card, a booklet, a passport, or the like. The medium ejection device 100 may also be a facsimile, a copier, a multifunction printer (MFP, Multifunction Peripheral), or the like. Note that the transported medium may not be an original but may be a print target or the like, and the medium ejection device 100 may also be a printer or the like that forms an image on the transported medium.

[0015] 1, arrow A1 indicates the medium ejection direction, arrow A2 indicates the width direction perpendicular to the medium ejection direction, and arrow A3 indicates the height direction perpendicular to the medium transport path. Hereinafter, "upstream" refers to the upstream side of the medium ejection direction A1, and "downstream" refers to the downstream side of the medium ejection direction A1. The width direction A2 is an example of a direction that intersects with the medium ejection direction.

[0016] The medium ejection device 100 includes a lower housing 101, an upper housing 102, a mounting table 103, an ejection table 104, an operation device 105, a display device 106, and the like.

[0017] The upper housing 102 is disposed in a position that covers the top surface of the medium ejection device 100, and is engaged with the lower housing 101 by a hinge so that it can be opened and closed when a medium is jammed or when cleaning the inside of the medium ejection device 100, for example.

[0018] The placement stage 103 engages with the lower housing 101 and places media to be fed and transported on it. The ejection stage 104 engages with the upper housing 102 and places ejected media on it. Note that the ejection stage 104 may also engage with the lower housing 101.

[0019] The operation device 105 has input devices such as buttons and an interface circuit for acquiring signals from the input devices, accepts input operations by a user, and outputs operation signals in response to the user's input operations. The display device 106 has a display such as a liquid crystal display, an organic EL (Electro-Luminescence) display, or the like, and an interface circuit for outputting image data to the display, and displays the image data on the display.

[0020] FIG. 2 is a diagram for explaining a transport path inside the medium ejection device.

[0021] The transport path inside the media discharge 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 transport roller 116, a first opposing roller 117, a fourth media sensor 118, an imaging device 119, a discharge roller 120, and a second opposing roller 121, etc.

[0022] The number of each of the feed roller 112, separation roller 113, transport roller 116, first opposing roller 117, discharge roller 120, and / or second opposing roller 121 is not limited to one, and may be more than one. In this case, the multiple feed rollers 112, separation rollers 113, transport roller 116, first opposing roller 117, discharge roller 120, and / or second opposing roller 121 are arranged side by side at intervals in the width direction A2.

[0023] 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 Figure 2, the medium transport path has a so-called straight path mechanism in which the vertical positional relationship between the front and back surfaces of the medium does not change between the state before transport when the medium is placed on loading tray 103 and the state after ejection when the medium is placed on ejection tray 104. Because the medium transport path has a straight path mechanism, medium ejection device 100 can be formed compactly.

[0024] The first medium sensor 111 is disposed upstream of the feed roller 112 and the separation roller 113. The first medium sensor 111 has a contact detection sensor and detects whether or not a medium is placed on the placement table 103. The first medium sensor 111 generates and outputs a first medium signal whose signal value changes depending on whether or not a medium is placed on the placement table 103. Note that the first medium sensor 111 is not limited to a contact detection sensor, and any other sensor capable of detecting the presence or absence of a medium, such as an optical detection sensor, may be used as the first medium sensor 111.

[0025] The feed roller 112 is provided in the lower housing 101, and separates and feeds the media placed on the mounting table 103 in order from the bottom up. The feed roller 112 is an example of a transport roller. The separation roller 113 is a so-called brake roller or retard roller, and is provided in the upper housing 102, and is disposed opposite to the feed roller 112. The separation roller 113 is provided so as to be rotatable or stoppable in the direction A5 opposite to the medium feeding direction. Note that a separation pad may be used instead of the separation roller 113.

[0026] The conveying roller 116 and the first opposing roller 117 are disposed opposite each other downstream of the feeding roller 112 and the separation roller 113 in the medium discharge direction A1. The conveying roller 116 and the first opposing roller 117 convey the medium fed by the feeding roller 112 and the separation roller 113 to the imaging device 119.

[0027] The imaging device 119 is an example of a processing unit, and performs a predetermined process on the medium transported by the transport rollers 116. The imaging device 119 is an example of an imaging unit, and as the predetermined process, captures an image of the medium transported by the transport rollers 116. The imaging device 119 includes a first imaging device 119a and a second imaging device 119b that are arranged opposite each other across the medium transport path.

[0028] The first imaging device 119a includes a first imaging sensor 119c, which is a CIS (Contact Image Sensor) with a life-size optical system and has CMOS (Complementary Metal Oxide Semiconductor) imaging elements linearly arranged in the main scanning direction. The first imaging sensor 119c captures an image of the medium surface at a first imaging position P1. The first imaging device 119a also includes 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 an area of ​​the surface of the medium being conveyed facing the first imaging sensor 119c at regular intervals, sequentially generating and outputting line images. That is, the line image has one pixel in the vertical direction (sub-scanning direction) and multiple pixels in the horizontal direction (main scanning direction).

[0029] Similarly, the second imaging device 119b has a second imaging sensor 119d using a CIS with a life-size optical system and CMOS imaging elements 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 device 119b also has a lens that forms an image on the imaging element and an A / D converter that amplifies and analog-to-digital (A / D) converts the electrical signal output from the imaging element. The second imaging device 119b captures an image of the area facing the second imaging sensor 119d on the back surface of the medium being transported at regular intervals, sequentially generating and outputting line images.

[0030] Note that medium ejection device 100 may have only one of first imaging device 119a and second imaging device 119b, and may read only one side of the medium. Also, first imaging sensor 119c and / or second imaging sensor 119d may be a CIS line sensor with a life-size optical system equipped with a CCD (Charge Coupled Device) imaging element. Also, first imaging sensor 119c and / or second imaging sensor 119d may be a reduction optical system line sensor with a CMOS or CCD imaging element. Furthermore, in the medium ejection direction A1, second imaging position P2 of second imaging sensor 119d may be located at the same position as or upstream of first imaging position P1 of first imaging sensor 119c.

[0031] The discharge roller 120 and the second opposed roller 121 are arranged facing each other downstream of the imaging device 119 in the medium discharge direction A1. The discharge roller 120 and the second opposed roller 121 discharge the medium that has been transported by the transport roller 116 and the first opposed roller 117 and processed (imaged) by the imaging device 119 to the discharge tray 104. The discharge roller 120 and the second opposed roller 121 are the only roller pair arranged downstream of the imaging device 119 in the medium discharge direction A1. The distance between the transport roller 116, which is arranged upstream of the imaging device 119, and the discharge roller 120, which is arranged furthest downstream, in the medium discharge direction A1 is shorter than the minimum medium length supported by the medium discharge device 100. This allows the medium discharge device 100 to reduce its device size.

[0032] The media placed on the mounting table 103 is transported between the lower guide 107a and the upper guide 107b in the media discharge direction A1 by the rotation of the feed roller 112 in the direction of arrow A4 in Figure 2, i.e., the media feed direction. When transporting the media, the separation roller 113 rotates in the direction of arrow A5, i.e., the opposite direction to the media feed direction. When multiple media are placed on the mounting table 103, the feed roller 112 and the separation roller 113 work to separate only the media placed on the mounting table 103 that are in contact with the feed roller 112. This restricts the transport of media other than the separated media (preventing double feeding).

[0033] The medium is fed between the conveying roller 116 and the first opposing roller 117 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 conveying roller 116 and the first opposing roller 117 rotate in the directions of arrows A6 and A7, respectively. The medium read by the imaging device 119 is discharged onto the discharge tray 104 as the discharge roller 120 and the second opposing roller 121 rotate in the directions of arrows A8 and A9, respectively. The discharge tray 104 holds the media discharged by the discharge roller 120 and the second opposing roller 121.

[0034] As shown in FIG. 2, the medium ejection device 100 also has a first motor 131, a second motor 132, and a third motor 133 as drive sources for the rollers.

[0035] The first motor 131 is provided in the lower housing 101 and is connected to the feed roller 112 via a first transmission mechanism 131a to drive the feed roller 112. The first motor 131 generates a driving force for rotating the feed roller 112 in response to a control signal from the processing circuit, thereby feeding the medium. The first motor 131 may be provided in the upper housing 102. The first transmission mechanism 131a includes one or more pulleys, belts, gears, etc., provided between the first motor 131 and a shaft 112a that is the rotation axis of the feed roller 112, and transmits the driving force generated by the first motor 131 to the feed roller 112.

[0036] The second motor 132 is provided in the upper housing 102 separately from the first motor 131, and is connected to the separation roller 113 via a second transmission mechanism 132a to drive the separation roller 113. The second motor 132 generates a driving force for rotating the separation roller 113 in response to a control signal from the processing circuit, causing the separation roller 113 to separate, feed, and transport the media. The second motor 132 may be provided in the lower housing 101. The second transmission mechanism 132a includes one or more pulleys, belts, gears, etc., provided between the second motor 132 and a shaft 113a, which is the rotation axis of the separation roller 113. The second transmission mechanism 132a transmits the driving force generated by the second motor 132 to the separation roller 113.

[0037] The third motor 133 is an example of a motor. The third motor 133 is provided in the lower housing 101 separately from the first motor 131 and the second motor 132. The third motor 133 is connected to the transport roller 116 and the discharge roller 120 via a third transmission mechanism 133a and drives the transport roller 116 and the discharge roller 120. The third motor 133 generates a driving force for rotating the transport roller 116 and the discharge roller 120 in response to a control signal from the processing circuit, causing the transport roller 116 and the discharge roller 120 to transport and discharge the medium. The third motor 133 may be provided in the upper housing 102. The third transmission mechanism 133a includes one or more pulleys, belts, gears, etc. provided between the third motor 133 and the shaft 116a, which is the rotation axis of the transport roller 116, and the shaft 120a, which is the rotation axis of the discharge roller 120. The third transmission mechanism 133 a transmits the driving force generated by the third motor 133 to the conveying roller 116 and the discharge roller 120 .

[0038] In this way, in medium discharge device 100, the third motor 133 is used in common as the motor for driving conveyance roller 116 and the motor for driving discharge roller 120. This allows medium discharge device 100 to reduce the number of motors, thereby reducing the cost, size, and weight of the device.

[0039] The first opposing roller 117 is a driven roller that rotates following the conveyance roller 116, and the second opposing roller 121 is a driven roller that rotates following the discharge roller 120. The first opposing roller 117 and / or the second opposing roller 121 may be driven by a driving force from a third motor 133. In this case, one or more gears are further provided between the shaft 116a of the conveyance roller 116 and the shaft 117a that is the rotation axis of the first opposing roller 117 and / or between the shaft 120a of the discharge roller 120 and the shaft 121a that is the rotation axis of the second opposing roller 121. The third transmission mechanism 133a further transmits the driving force generated by the third motor 133 to the first opposing roller 117 and / or the second opposing roller 121.

[0040] Furthermore, the separation roller 113, the transport roller 116, and the discharge roller 120 may be driven by a common motor.

[0041] FIG. 3 is a schematic diagram for explaining the arrangement positions of the medium sensors.

[0042] 3 is a schematic diagram of the lower housing 101 in the open state, viewed from the conveying path side. In the example shown in FIG. 3, the feed rollers 112, separation rollers 113, conveying rollers 116, first opposing rollers 117, discharge rollers 120, and second opposing rollers 121 are arranged in pairs.

[0043] The second medium sensor 114 and the third medium sensor 115 are an example of a plurality of second medium detection units. 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 spaced apart in the width direction A2. The second medium sensor 114 and the third medium sensor 115 are arranged so that the distance W in the width direction A2 between them 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 transport roller 116 and the first opposing roller 117. Note that the second medium sensor 114 and the third medium sensor 115 may also be arranged downstream of the transport roller 116 and the first opposing roller 117. The second medium sensor 114 and the third medium sensor 115 detect the leading and trailing edges of the medium transported to that position.

[0044] 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 opposite the light emitter and light receiver across the medium transport path. The light guide member is a light guide tube such as a U-shaped prism. The light emitter is an LED (Light Emitting Diode) or the like and emits light toward the transport path. The light receiver is a photodiode or the like and receives the light emitted by the light emitter and guided by the light guide member. When a medium is present in a position opposite the second medium sensor 114, the light emitted from the light emitter is blocked by the medium, and the light receiver does not detect the light emitted from the light emitter. The light receiver generates and outputs a second medium signal based on the intensity of the received light. The signal value changes depending on whether a medium is present or not at the position of the second medium sensor 114.

[0045] 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 opposite the light emitter and light receiver across the medium transport path. The light guide member is a light guide tube such as a U-shaped prism. The light emitter is an LED or the like and emits light toward the transport path. Meanwhile, the light receiver is a photodiode or the like and receives the light emitted by the light emitter and guided by the light guide 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.

[0046] The fourth medium sensor 118 is an example of a medium detection unit. The fourth medium sensor 118 is disposed downstream of the feed roller 112 and the separation roller 113 in the medium discharge direction A1, particularly downstream of the transport roller 116 and the first opposing roller 117, and upstream of the imaging device 119. That is, the fourth medium sensor 118 is disposed between the transport roller 116, the first opposing roller 117, and the imaging device 119. The fourth medium sensor 118 is also disposed in the center in the width direction A2, particularly between the two transport rollers 116 and between the two first opposing rollers 117. The fourth medium sensor 118 may be disposed upstream of the transport roller 116 and the first opposing roller 117 in the medium discharge direction A1, particularly at 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. The fourth medium sensor 118 detects the leading and trailing edges of a medium transported to its position.

[0047] The fourth medium sensor 118 includes a light emitter and a light receiver provided on one side of the medium transport path, and a light guide member provided opposite the light emitter and light receiver across the medium transport path. The light guide member is a light guide tube such as a U-shaped prism. The light emitter is an LED or the like and emits light toward the transport path. The light receiver is a photodiode or the like and receives the light emitted 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 fourth medium signal whose signal value changes depending on whether a medium is present or not at the position of the fourth medium sensor 118.

[0048] Note that 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, and / or fourth medium sensor 118. Also, in second medium sensor 114, third medium sensor 115, and / or fourth medium sensor 118, the light emitter and light receiver may be positioned opposite each other across the transport path. Also, second medium sensor 114, third medium sensor 115, and / or fourth medium sensor 118 may detect the presence of a 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.

[0049] FIG. 4 is a block diagram showing a schematic configuration of the medium ejection device.

[0050] In addition to the components described above, the medium ejection device 100 further includes an interface device 134, a storage device 140, a processing circuit 150, and the like.

[0051] The interface device 134 has an interface circuit conforming to a serial bus such as USB, and is electrically connected to an information processing device (not shown) (e.g., a personal computer, a portable information terminal, etc.) to transmit and receive input images and various information. Alternatively, instead of the interface device 134, a communication unit having an antenna for transmitting and receiving wireless signals and a wireless communication interface device for transmitting and receiving signals via a wireless communication line in accordance with a predetermined communication protocol may be used. The predetermined communication protocol is, for example, a wireless LAN (Local Area Network). The communication unit may have a wired communication interface device for transmitting and receiving signals via a wired communication line in accordance with a communication protocol such as a wired LAN.

[0052] Storage device 140 includes a memory device such as a RAM (Random Access Memory) or a ROM (Read Only Memory), a fixed disk device such as a hard disk, or a portable storage device such as a flexible disk or optical disk. Storage device 140 also stores computer programs, databases, tables, and the like used for various processes of medium ejection device 100. The computer programs may be installed into storage device 140 from a computer-readable portable recording medium using a known setup program or the like. Examples of portable recording media include a CD-ROM (Compact Disc Read Only Memory) and a DVD-ROM (Digital Versatile Disc Read Only Memory). The computer programs may also be distributed from a server or the like and installed into storage device 140.

[0053] The processing circuit 150 operates based on a program stored in advance in the storage device 140. The processing circuit is, for example, a CPU (Central Processing Unit). The processing circuit 150 may be a DSP (Digital Signal Processor), an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or the like.

[0054] 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 118, the imaging device 119, the first motor 131, the second motor 132, the third motor 133, the interface device 134, the storage device 140, and the like, and controls each of these components. The processing circuit 150 performs drive control of the first motor 131, the second motor 132, and the third motor 133, image capture control of the imaging device 119, and the like, acquires a line image from the imaging device 119 to generate an input image, which is then sent to the information processing device via the interface device 134. The processing circuit 150 also detects the amount of skew of the medium, and controls the discharge rollers 120 before the trailing edge of the medium passes through them, based on the detection result of the medium by the fourth medium sensor 118 and the detected amount of skew.

[0055] FIG. 5 is a diagram showing a schematic configuration of a storage device and a processing circuit.

[0056] 5, the storage device 140 stores a control program 141, a skew amount detection program 142, a width detection program 143, and the like. Each of these programs is a functional module implemented by software running on a processor. The processing circuit 150 reads each program stored in the storage device 140 and operates in accordance with the read program. As a result, the processing circuit 150 functions as a control unit 151, a skew amount detection unit 152, and a width detection unit 153.

[0057] 6 and 7 are flowcharts showing an example of the operation of the medium conveyance process of the medium ejection device.

[0058] 6 and 7, an example of the operation of the medium conveyance process of medium ejection device 100 will be described below. 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 memory device 140 in advance.

[0059] First, the control unit 151 waits until the user inputs an instruction to read a medium using the operation device 105 or the information processing device, and an operation signal instructing the reading of a medium is received from the operation device 105 or the interface device 134 (step S101).

[0060] Next, the control unit 151 acquires each setting related to the imaging process, image processing, or transport process from the profile included in the operation signal (step S102). The profile is a setting related to the imaging process, image processing, or transport process that is set by the user depending on the purpose of the image to be generated or the type of medium to be imaged. The profile includes a setting for the resolution of the image captured by the imaging device 119 and a discharge mode. The discharge mode includes a speed change mode that changes the speed of the discharge rollers 120 when discharging a medium, and a speed fixed mode that does not change the speed of the discharge rollers 120 when discharging a medium. The profile may be specified by the user before the read command is input and stored in the storage device 140, rather than being specified together with the read command. In this case, the control unit 151 acquires the profile by reading it from the storage device 140.

[0061] Next, control unit 151 acquires a first medium signal from first medium sensor 111, and determines whether or not a medium is placed on mounting table 103 based on the acquired first medium signal (step S103). If no medium is placed on mounting table 103, control unit 151 ends the series of steps.

[0062] On the other hand, if a medium is placed on the placement table 103, the control unit 151 determines the speed of each roller based on the resolution acquired in step S102 (step S104). The control unit 151 determines the speed of each roller as the transport speed of the medium by each roller, i.e., the movement speed of the surface of each roller. The control unit 151 may determine the rotation speed of each roller as the speed of each roller. The higher the resolution, the shorter the image capture interval by the imaging device 119 and the lower the speed of each roller is set. On the other hand, the lower the resolution, the longer the image capture interval by the imaging device 119 and the higher the speed of each roller is set. A table or formula indicating the correspondence between the resolution and the speed of each roller is stored in advance in the storage device 140, and the control unit 151 refers to the table or formula stored in the storage device 140 to identify the speed of each roller corresponding to each resolution.

[0063] 8 and 9 are graphs for explaining the speed change of each roller.

[0064] FIG. 8 shows the speed change of each roller when the resolution is equal to or less than a predetermined resolution threshold, and FIG. 9 shows the speed change of each roller when the resolution is greater than the resolution threshold. In FIGS. 8 and 9, graphs G11 and G21 show the speed change of the feed roller 112, and graphs G12 and G22 show the speed change of the transport roller 116. Since the speeds of the first opposing roller 117, discharge roller 120, and second opposing roller 121 change in the same way as the speed of the transport roller 116, the following will explain the speed change of the transport roller 116 as a representative. The horizontal axis of each of graphs G11, G11, G21, and G22 represents time, and the vertical axis represents the transport speed of the medium by each roller. Meanwhile, graphs G13 and G23 show the change in the signal value of the fourth medium signal. The horizontal axis of each of graphs G13 and G23 represents time, and the vertical axis represents the signal value. In this embodiment, when no medium is present at the position of the fourth medium sensor 118, the signal value of the fourth medium signal is L, and when a medium is present at the position of the fourth medium sensor 118, the signal value of the fourth medium signal is H.

[0065] 8 and 9, time T1 indicates the start of medium conveyance. The control unit 151 starts the rotation of the conveyance roller 116 at time T1, and starts the rotation of the feed roller 112 at time T2, a predetermined time after time T1. As shown in FIG. 8, when the resolution is equal to or less than the resolution threshold, the control unit 151 sets the speed of the conveyance roller 116 to an initial speed U1 and the speed of the feed roller 112 to an initial speed V1. The initial speed V1 is set to a speed lower (slower) than the initial speed U1. On the other hand, as shown in FIG. 9, when the resolution is greater than the resolution threshold, the control unit 151 sets the speed of the conveyance roller 116 to an initial speed U1' and the speed of the feed roller 112 to an initial speed V1'. The initial speed V1' is set to a speed lower than the initial speed U1'. Furthermore, the initial speeds U1' and V1' are set to speeds lower than the initial speeds U1 and V1, respectively.

[0066] Next, the control unit 151 drives the first motor 131, the second motor 132, and the third motor 133. As a result, the control unit 151 rotates the feed roller 112, the separation roller 113, the transport roller 116, the first opposing roller 117, the discharge roller 120, and / or the second opposing roller 121 to transport the medium (step S105).

[0067] The control unit 151 controls the first motor 131, the second motor 132, and the third motor 133 to rotate each roller at the speed determined in step S104. As shown in FIGS. 8 and 9, after a predetermined slew-up period has elapsed since the start of driving each motor at time T1 or T2, each roller rotates at the determined speed. Similarly, if the control unit 151 increases the speed of each roller, after a predetermined slew-up period has elapsed since the start of driving each motor, each roller rotates at the set speed. Similarly, if the control unit 151 reduces the speed of each roller, after a predetermined slew-down period has elapsed since the start of driving each motor, each roller rotates at the set speed.

[0068] Next, the control unit 151 waits until the leading edge of the transported medium passes a first predetermined position (step S106). The first predetermined position is set, for example, to a position between the feed roller 112 and separation roller 113 and the transport roller 116 and first opposing roller 117 in the medium discharge direction A1. In particular, the first predetermined position is set downstream of and near the nip portion between the feed roller 112 and separation roller 113 in the medium discharge direction A1. For example, the control unit 151 periodically acquires a second medium signal and a third medium signal from the second medium sensor 114 and the third medium sensor 115. The control unit 151 determines that the leading edge of the medium has passed the first predetermined position when the signal value of either the second medium signal or the third medium signal changes from a value indicating the absence of a medium to a value indicating the presence of a medium. The control unit 151 may also determine that the leading edge of the medium has passed the first predetermined position when a first predetermined time has elapsed since the start of medium feeding. The first predetermined time is set to the time required for the medium to move from the upstream end to the downstream end of the nip portion between the feed roller 112 and the separation roller 113 plus a margin.

[0069] Next, the control unit 151 changes the speed of the feeding roller 112 (step S107).

[0070] 8 and 9, time T3 indicates the time when the leading edge of the medium passes the first predetermined position. As shown in FIG. 8, when the resolution is equal to or lower than the resolution threshold, the control unit 151 changes the speed of the feed roller 112 to a final speed V2. The final speed V2 of the feed roller 112 is set to a speed that is higher than the initial speed V1 of the feed roller 112 and lower than the initial speed U1 of the transport roller 116. The final speed V2 of the feed roller 112 may be set to the same speed as the initial speed U1 of the transport roller 116. On the other hand, as shown in FIG. 9, when the resolution is equal to or lower than the resolution threshold, the control unit 151 changes the speed of the feed roller 112 to a final speed V2'. The final speed V2' of the feed roller 112 is set to a speed that is higher than the initial speed V1' of the feed roller 112 and lower than the initial speed U1' of the transport roller 116. The final speed V2' of the feed roller 112 may be set to the same speed as the initial speed U1' of the transport roller 116. Furthermore, final speed V2' is set to a speed lower than final speed V2. In this way, control unit 151 gradually increases the speed of feed roller 112 while reducing the speed of feed roller 112 during the medium separation period. This enables control unit 151 to reduce the processing time required for the medium conveyance process while suppressing the occurrence of double feeding or jamming of media and loss of synchronization of first motor 131. Therefore, control unit 151 can achieve both feeding performance (reduced occurrence of abnormalities) and processing performance (reduced conveyance time).

[0071] Next, control unit 151 waits until the leading edge of the transported medium passes a second predetermined position (step S108). The second predetermined position is set, for example, to a position between transport roller 116 and first opposing roller 117 and the imaging position of imaging device 119 in medium discharge direction A1. For example, the second predetermined position is set to the arrangement position of fourth medium sensor 118. Control unit 151 periodically acquires a fourth medium signal from fourth medium sensor 118, and determines that the leading edge of the medium has passed the second predetermined position 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.

[0072] Next, the control unit 151 controls the first motor 131 to stop the feeding roller 112 (step S109).

[0073] 8 and 9, time T4 indicates the time when the leading edge of the medium passes the position of fourth medium sensor 118. As shown in FIGS. 8 and 9, after the leading edge of the medium passes the position of fourth medium sensor 118, control unit 151 stops feed roller 112 (changes the speed to 0). As a result, the medium is subsequently transported by transport roller 116, and feed roller 112 rotates along with the transported medium. By stopping feed roller 112, control unit 151 can prevent the medium from being pushed by feed roller 112 and bending between feed roller 112 and transport roller 116, which could cause a medium jam.

[0074] Next, the control unit 151 causes the imaging device 119 to start imaging the medium (step S110). Thereafter, every time the imaging device 119 generates a predetermined number of line images, the control unit 151 acquires the line images from the imaging device 119 and stores them in the storage device 140. The predetermined number is set to one or more arbitrary numbers.

[0075] Next, the control unit 151 waits until the trailing edge of the transported medium passes the first predetermined position (step S111). The control unit 151 determines that the trailing edge of the medium has passed the first predetermined position when the signal value of either the second medium signal or the third 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 may also determine that the trailing edge of the medium has passed the first predetermined position when a second predetermined time has elapsed since the start of feeding the medium. The second predetermined time is set to the time required for the leading edge of the largest size medium supported by the medium ejection device 100 to move from the upstream end of the nip portion between the feed roller 112 and the separation roller 113 to the downstream end of the nip portion, plus a margin.

[0076] Next, control unit 151 determines whether or not a medium remains on mounting table 103 based on the first medium signal received from first medium sensor 111 (step S112).

[0077] If media remain on the mounting table 103, the control unit 151 drives the first motor 131 to rotate the feed roller 112 and feed and transport the subsequent media (step S113). The control unit 151 controls the first motor 131 to rotate the feed roller 112 at the initial speed determined in step S104.

[0078] 8 and 9, time T5 indicates the time when the trailing edge of the medium passes the first predetermined position. As shown in Fig. 8, when the resolution is equal to or less than the resolution threshold, the control unit 151 sets the speed of the feed roller 112 to an initial speed V1. On the other hand, as shown in Fig. 9, when the resolution is greater than the resolution threshold, the control unit 151 sets the speed of the feed roller 112 to an initial speed V1'.

[0079] Next, the control unit 151 waits until the leading edge of the succeeding medium passes the first predetermined position (step S114), in the same manner as in the process of step S106.

[0080] Next, the control unit 151 changes the speed of the feed roller 112 in the same manner as in the process of step S107 (step S115).

[0081] 8, when the resolution is equal to or less than the resolution threshold, the control unit 151 changes the speed of the feed roller 112 to the final speed V2. On the other hand, when the resolution is equal to or less than the resolution threshold, the control unit 151 changes the speed of the feed roller 112 to the final speed V2', as shown in FIG.

[0082] Next, the control unit 151 waits until the trailing edge of the preceding medium passes the third predetermined position (step S116). The third predetermined position is set to a position downstream of either the first imaging position P1 of the first imaging device 119a or the second imaging position P2 of the second imaging device 119b, whichever is located downstream, by the overscan amount in the medium ejection direction A1. The initial value of the overscan amount is preset to an amount (e.g., 16 mm) that is likely to capture the entire medium even if the medium is transported at an angle. The overscan amount can be changed in the ejection control process described below. The control unit 151 periodically acquires a fourth medium signal from the fourth medium sensor 118, and determines that the trailing edge of the preceding medium has passed the position of the fourth medium sensor 118 when the signal value of the fourth medium signal changes from a value indicating the presence of a medium to a value indicating the absence of a medium. The control unit 151 determines that the trailing edge of the preceding medium has passed the position of the fourth medium sensor 118 when a third predetermined time has elapsed since the trailing edge of the preceding medium passed the position of the fourth medium sensor 118. The third predetermined time is set to the time required for the medium to move from the position of the fourth medium sensor 118 to the third predetermined position.

[0083] Next, the control unit 151 stops imaging by the imaging device 119. The control unit 151 generates an input image by combining line images of the preceding medium that have been acquired up to now from the imaging device 119, and outputs the input image by sending it to the information processing device via the interface device 134 (step S117). By continuing imaging by the imaging device 119 until the rear end of the medium reaches a position downstream from the imaging position by the overscan amount, the medium ejection device 100 can image the entire medium even if the medium is transported at an angle.

[0084] Next, the control unit 151 returns the process to step S108 and repeats the processes from step S108 onwards for the subsequent medium. In this case, in step S108, the control unit 151 waits until the leading edge of the subsequent medium passes the second predetermined position (time T9 in FIGS. 8 and 9), and in step S109, controls the first motor 131 to stop the feed roller 112.

[0085] On the other hand, if no media remain on the mounting table 103 in step S112, the control unit 151 waits until the rear end of the transported medium passes the third predetermined position, similar to the process in step S116 (step S118).

[0086] Next, the control unit 151 generates an input image in the same manner as in the process of step S117, and outputs it by transmitting it to the information processing device via the interface device 134 (step S119).

[0087] Next, control unit 151 waits until the trailing edge of the transported medium passes discharge rollers 120 (step S120). Control unit 151 determines that the trailing edge of the medium has passed discharge rollers 120 when a fourth predetermined time has elapsed since the trailing edge of the medium passed the position of fourth medium sensor 118. The fourth predetermined time is set to a value obtained by adding a margin to the time required for the medium to move from the position of fourth medium sensor 118 to the downstream end position of the nip portion between discharge rollers 120 and second opposing roller 121.

[0088] Next, the control unit 151 controls the second motor 132 and the third motor 133 to stop the separation roller 113, the conveying roller 116, the first opposing roller 117, the discharge roller 120 and / or the second opposing roller 121 (step S121), and ends the series of steps.

[0089] The processes of steps S106 and S107 and / or steps S114 and S115 may be omitted. In that case, in step S105 and / or step S113, the feed roller 112 may be set to the final speed V2, V2' at the start of rotation.

[0090] FIG. 10 is a flowchart showing an example of the operation of the discharge control process of the medium discharge device.

[0091] An example of the operation of the discharge control process of medium discharge device 100 will be described below with reference to the flowchart shown in Figure 10. The flow of the operation described below is executed mainly by processing circuit 150 in cooperation with each element of medium discharge device 100 based on a program stored in advance in storage device 140. The discharge control process is executed in parallel with the discharge control process each time a medium is transported.

[0092] First, the control unit 151 determines whether the discharge mode acquired in step S102 of Fig. 6 is set to the variable speed mode or the fixed speed mode (step S201). If the discharge mode is set to the fixed speed mode, the control unit 151 ends the series of steps without changing the speed of the discharge rollers 120.

[0093] On the other hand, if the ejection mode is set to the speed change mode, the control unit 151 waits until the leading edge of the medium passes a fourth predetermined position (step S202). The fourth predetermined position is set, for example, to a position a predetermined distance downstream from the imaging position of the imaging device 119 in the medium ejection direction A1. For example, the control unit 151 periodically acquires a fourth medium signal from the fourth medium sensor 118, and determines that the leading edge of the medium has passed the position of the fourth medium sensor 118 when the signal value of the fourth medium signal changes from a value indicating the absence of a medium to a value indicating the presence of a medium. The control unit 151 determines that the leading edge of the medium has passed the imaging position when a fifth predetermined time has elapsed since the leading edge of the medium passed the position of the fourth medium sensor 118. The fifth predetermined time is set to a value obtained by adding a margin to the time required for the medium to move from the position of the fourth medium sensor 118 to the fourth predetermined position. The control unit 151 may also determine that the leading edge of the medium has passed the fourth predetermined position when a sixth predetermined time has elapsed since the start of medium feeding. The sixth predetermined time is set to the time required for the medium to move from the upstream end of the nip portion between the feed roller 112 and the separation roller 113 to the fourth predetermined position plus a margin.

[0094] Next, the skew amount detection unit 152 detects the amount of skew of the medium (step S203).

[0095] For example, the skew amount detection unit 152 detects the amount of skew of the medium based on a line image generated by the imaging device 119. The skew amount detection unit 152 generates a partial image by combining line images acquired from the imaging device 119 up to now, and detects the amount of skew of the medium from the generated partial image. The skew amount detection unit 152 first calculates, for each vertical line extending in the vertical direction (sub-scanning direction) within the partial image, starting from the top, the absolute value of the difference in gradation value between each pixel on each vertical line and its adjacent pixels in the vertical direction (hereinafter referred to as the adjacent difference value). The skew amount detection unit 152 detects, as edge pixels, pixels within each vertical line whose adjacent difference value exceeds a gradation threshold. The gradation value is a brightness value or a color value (R value, G value, or B value), etc. The gradation threshold is set, for example, to a brightness value difference (e.g., 20) that allows a person to visually distinguish differences in brightness on an image. The skew amount detection unit 152 detects the edge pixel located at the uppermost side in each vertical line as the upper edge pixel.

[0096] The skew amount detection unit 152 may calculate the absolute value of the difference in gradation values ​​between two pixels that are a predetermined distance away from each pixel in the vertical direction as the adjacent difference value. The skew amount detection unit 152 may also detect edge pixels by comparing the gradation value of each pixel with a threshold. For example, if the gradation value of a specific pixel is less than the threshold and the gradation value of a pixel that is vertically adjacent to the specific pixel or a pixel that is a predetermined distance away from the specific pixel is equal to or greater than the threshold, the skew amount detection unit 152 detects the specific pixel as an edge pixel.

[0097] Next, the skew amount detection unit 152 detects a straight line (line segment) from the top edge pixels using the least squares method as the top edge of the medium. The skew amount detection unit 152 may also detect the straight line using a Hough transform. Furthermore, if multiple straight lines are detected from the top edge pixels, the skew amount detection unit 152 may detect the straight line with the longest length in the horizontal direction (main scanning direction) as the top edge of the medium. The skew amount detection unit 152 detects the angle between the detected straight line (top edge of the medium) and the horizontal direction as the skew amount of the medium. The skew amount detection unit 152 can detect the skew amount of the medium with high accuracy by using a line image generated by the imaging device 119.

[0098] The skew amount detection unit 152 may detect the amount of skew of the medium based on a line image captured by the imaging device whose imaging position is located upstream of the first imaging device 119a or the second imaging device 119b. This allows the skew amount detection unit 152 to detect the amount of skew of the medium at an earlier stage.

[0099] Alternatively, the skew amount detection unit 152 may detect the amount of skew of the medium based on the detection results of the medium by the second medium sensor 114 and the third medium sensor 115. In this case, the skew amount detection unit 152 detects the time when the leading edge of the medium passes the position of the second medium sensor 114 and the position of the third medium sensor 115, and calculates the time difference between them, similar to the process of step S104 in FIG. 6. The skew amount detection unit 152 multiplies the calculated time difference by the medium transport speed to detect the multiplied value (i.e., the distance traveled by the leading edge of the medium from passing one of the positions of the second medium sensor 114 and the third medium sensor 115 until passing the other) as the amount of skew of the medium. The skew amount detection unit 152 may also detect the divided value (i.e., the tangent of the leading edge of the medium to the width direction A2) by dividing the multiplied value by the distance W in the width direction A2 between the second medium sensor 114 and the third medium sensor 115 as the amount of skew of the medium. The skew amount detection unit 152 may detect the arctangent of the divided value (i.e., the angle of the leading edge of the medium with respect to the width direction A2) as the skew amount of the medium. The skew amount detection unit 152 can detect the skew amount of the medium with high accuracy even when using the detection results of the medium by each medium sensor.

[0100] Alternatively, the skew amount detection unit 152 may detect the amount of skew of the medium based on the trailing edge of the medium. In this case, in step S202, the control unit 151 waits until the trailing edge of the medium passes a third predetermined position. The skew amount detection unit 152 detects the edge pixel located at the bottom of each vertical line as the bottom edge pixel. The skew amount detection unit 152 detects a straight line from the bottom edge pixels using the least squares method or a Hough transform as the bottom edge of the medium, and detects the angle between the detected straight line and the horizontal direction as the amount of skew of the medium. Alternatively, the skew amount detection unit 152 detects the amount of skew of the medium based on the time difference between the time when the trailing edge of the medium passes the position of the second medium sensor 114 and the time when it passes the position of the third medium sensor 115. This allows the medium ejection device 100 to control the ejection of the medium based on the state of the medium immediately before ejection when the medium is rotating, allowing for more appropriate ejection of the medium. On the other hand, the medium ejection device 100 can detect the amount of skew of the medium based on the leading edge of the medium, thereby being able to identify the amount of skew of the medium early on and being able to execute medium ejection control with ample time to spare.

[0101] The skew amount detection unit 152 may also detect the amount of skew of the medium based on the left and / or right edges of the medium. In this case, the skew amount detection unit 152 calculates the horizontal adjacent difference value of each pixel in each horizontal line extending horizontally (in the main scanning direction) within the partial image, starting from the left, and detects pixels whose adjacent difference value exceeds a gradation threshold as edge pixels. The width detection unit 153 detects the leftmost edge pixel in each horizontal line as the left edge of the medium, and the rightmost pixel as the right edge of the medium. The skew amount detection unit 152 may also calculate the absolute value of the difference in gradation values ​​between two pixels horizontally separated by a predetermined distance from each pixel as the adjacent difference value. The skew amount detection unit 152 may also detect edge pixels by comparing the gradation value of each pixel with a threshold. For example, if the gradation value of a specific pixel is less than a threshold value and the gradation value of a pixel horizontally adjacent to the specific pixel or a pixel a predetermined distance away from the specific pixel is equal to or greater than the threshold value, the skew amount detection unit 152 detects the specific pixel as an edge pixel. The skew amount detection unit 152 detects a left-end edge pixel and / or a straight line from the left-end edge pixel as the left and / or right sides of the medium using the least squares method or a Hough transform, and detects the angle between the detected straight line and the vertical direction as the skew amount of the medium.

[0102] Next, the width detection unit 153 detects the width of the medium (step S204).

[0103] For example, the width detection unit 153 detects the width of the medium from the partial image. The width detection unit 153 detects the left and right edges of the medium on a predetermined horizontal line, and detects the distance between the detected left and right edges as the width of the medium.

[0104] The width detection unit 153 may detect the width of the medium based on a line image captured by the image capturing device located upstream of the first image capturing device 119a or the second image capturing device 119b. This allows the width detection unit 153 to detect the width of the medium more quickly.

[0105] Alternatively, width detection unit 153 may detect the width of the medium based on the detection results of the medium by the medium sensors. In this case, medium discharge device 100 has one or more medium sensors arranged in the same position as second medium sensor 114 and third medium sensor 115 in the medium discharge direction A1 and spaced apart from second medium sensor 114 and third medium sensor 115 in the width direction A2. Width detection unit 153 detects the width of the medium as the distance between the two outermost medium sensors in the width direction A2, among the medium sensors that detected the medium (passage).

[0106] Furthermore, the profile acquired in step S102 of FIG. 6 may include the size of the medium being transported, and the width detection unit 153 may identify the width of the medium from the size of the medium.

[0107] If the amount of skew and width of the medium are detected without using a partial image, the third predetermined position may be set upstream from the imaging position. This allows the medium ejection device 100 to quickly determine the amount of skew and width of the medium and allow for ample control over the ejection of the medium.

[0108] Next, the control unit 151 determines whether the skew amount of the medium detected by the skew amount detection unit 152 is equal to or less than a first threshold value (step S205). The first threshold value is an example of a skew amount threshold. The first threshold value is set to a value (e.g., a magnitude equivalent to 3°) obtained by subtracting a margin from the maximum skew amount of the medium at which the entire medium can be imaged when the medium is overscanned by the initial value of the overscan amount, for example.

[0109] If the amount of skew of the medium is greater than the first threshold, the control unit 151 determines whether the amount of skew of the medium is equal to or less than a second threshold that is greater than the first threshold (step S206). The second threshold is set to the minimum value of the amount of skew of the medium (e.g., a magnitude equivalent to 12°) at which the entire medium is not captured even though the medium has been overscanned by the initial value of the overscan amount. If the amount of skew of the medium is equal to or less than the second threshold, the control unit 151 ends the series of steps without changing the speed of the discharge rollers 120.

[0110] On the other hand, if the amount of skew of the medium is greater than the second threshold, the control unit 151 increases the amount of overscan by the imaging device 119 (step S207). The change value for the overscan amount is set in advance so that the entire medium is imaged even if the amount of skew of the medium is greater than the second threshold. The change value for the overscan amount may be set according to the amount of skew of the medium. In this case, the change value for the overscan amount is set to a larger value the greater the amount of skew of the medium. This allows the control unit 151 to increase the imaging time by the imaging device 119 in steps S116 and S117 of FIG. 7, and more reliably image the entire medium when the medium is transported at an angle. Next, the control unit 151 ends the series of steps without changing the speed of the discharge rollers 120.

[0111] On the other hand, if the amount of skew of the medium is equal to or less than the first threshold in step S205, the control unit 151 determines whether the width of the medium detected by the width detection unit 153 is equal to or less than the width threshold (step S208). The width threshold is set to a value (for example, 100 mm) between the width of a normal medium such as an A4-size PPC (Plain Paper Copier) sheet and the width of a small medium such as a business card or receipt.

[0112] If the width of the medium is equal to or less than the width threshold, the control unit 151 waits until the trailing edge of the medium passes the fifth predetermined position (step S209). The fifth predetermined position is set to a position downstream of the imaging position of the imaging device 119 and upstream of the discharge rollers 120 in the medium discharge direction A1. In particular, the fifth predetermined position is set to a position a first distance downstream of either the first imaging position P1 of the first imaging device 119a or the second imaging position P2 of the second imaging device 119b, whichever is located downstream. The first distance is set to a value smaller than the initial value of the overscan amount. For example, if the initial value of the overscan amount is set to 16 mm, the first distance is set to 5 mm. The control unit 151 determines that the trailing edge of the medium has passed the fifth predetermined position when a seventh predetermined time has elapsed since the trailing edge of the medium passed the position of the fourth medium sensor 118. The seventh predetermined time is set to the time required for the medium to move from the position of the fourth medium sensor 118 to the fifth predetermined position.

[0113] On the other hand, if the width of the medium is greater than the width threshold, the control unit 151 waits until the trailing edge of the medium passes the sixth predetermined position (step S210). The sixth predetermined position is set to a position downstream of the imaging position of the imaging device 119 and upstream of the discharge rollers 120 in the medium discharge direction A1. In particular, the sixth predetermined position is set to a position downstream of the downstream imaging position of either the first imaging position P1 of the first imaging device 119a or the second imaging position P2 of the second imaging device 119b in the medium discharge direction A1 by a second distance. The second distance is set to a value greater than the first distance and less than the initial value of the overscan amount. For example, if the initial value of the overscan amount is set to 16 mm and the first distance is set to 5 mm, the second distance is set to 11 mm. The control unit 151 determines that the trailing edge of the medium has passed the fifth predetermined position when an eighth predetermined time has elapsed since the trailing edge of the medium passed the position of the fourth medium sensor 118. The eighth predetermined time is set to the time required for the medium to move from the position of the fourth medium sensor 118 to the sixth predetermined position.

[0114] Next, the control unit 151 changes the speed of the discharge rollers 120 (step S211). If the resolution of the image captured by the imaging device 119 is equal to or less than the resolution threshold, the control unit 151 reduces the speed of the discharge rollers 120, and if the resolution of the image captured by the imaging device 119 is greater than the resolution threshold, the control unit 151 increases the speed of the discharge rollers 120. The changed speed of the discharge rollers 120 is set in advance to a speed at which the discharged medium does not fly out of the discharge tray 104, does not scatter on the discharge tray 104, and does not remain around the discharge opening.

[0115] 8 and 9, time T6 indicates the time when the trailing edge of the medium passes the position of the fourth medium sensor 118, and time T7 indicates the time when the trailing edge of the medium passes the fifth predetermined position. In the example shown in Figures 8 and 9, the control unit 151 changes the speed of the conveyance rollers 116 (discharge rollers 120) to discharge speed U2 at time T7 when the trailing edge of the medium passes the fifth predetermined position. Discharge speed U2 of the conveyance rollers 116 (discharge rollers 120) is set to a speed that is lower than the initial speed U1 of the conveyance rollers 116 when the resolution is equal to or less than the resolution threshold value and higher than the initial speed U1' of the conveyance rollers 116 when the resolution is greater than the resolution threshold value.

[0116] That is, when the resolution is equal to or less than the resolution threshold, the discharge speed U2 of the discharge rollers 120 is set to a speed lower than the initial speed U1. As a result, the medium discharge device 100 transports the medium at a high speed before discharging the medium to shorten the time required for the medium transport process, and discharges the medium at a low speed when discharging the medium, thereby preventing the medium from flying out of the discharge tray 104 or scattering on the discharge tray 104. On the other hand, when the resolution is greater than the resolution threshold, the discharge speed U2 of the discharge rollers 120 is set to a speed higher than the initial speed U1'. As a result, the medium discharge device 100 transports the medium at a low speed during medium imaging to reliably capture the medium, and discharges the medium at a high speed when discharging the medium, thereby preventing the medium from remaining around the discharge port and causing a media jam.

[0117] In this way, the control unit 151 controls the discharge rollers 120 based on the detection result by the fourth medium sensor 118 and the amount of skew of the medium before the rear end of the medium passes the discharge rollers 120. This allows the medium discharge device 100 to change the speed of the discharge rollers 120 when it is estimated that imaging of the entire medium has been completed based on the position and amount of skew of the medium.

[0118] In particular, the control unit 151 changes the speed of the discharge rollers 120 on the condition that the skew amount of the medium is equal to or less than the skew amount threshold. This allows the medium discharge device 100 to change the speed of the discharge rollers 120 when the skew amount of the medium is small and it is highly likely that imaging of the entire medium has been completed. Therefore, the medium discharge device 100 can prevent distortion (stretching or shrinking) from occurring in the generated input image due to a change in the medium transport speed while the imaging device 119 is imaging the medium.

[0119] Furthermore, as described above, the fifth predetermined position or the sixth predetermined position at which the speed of the discharge rollers 120 is changed is set upstream of the discharge rollers 120. Therefore, the control unit 151 changes the speed of the discharge rollers 120 before the rear end of the medium passes the discharge rollers 120. This allows the medium discharge device 100 to reliably change the discharge speed of the medium using the discharge rollers 120.

[0120] Furthermore, the control unit 151 changes the speed of the discharge rollers 120 based on the width of the medium. This allows the medium discharge device 100 to change the discharge rollers 120 early for small media that require a small amount of overscan, thereby more reliably preventing the media from flying off the discharge tray 104 or scattering on the discharge tray 104. On the other hand, the medium discharge device 100 increases the amount of overscan for regular media that require a large amount of overscan, allowing the entire medium to be imaged more reliably.

[0121] Note that, when the resolution of the image captured by the imaging device 119 is greater than the resolution threshold, the control unit 151 does not need to change the speed of the discharge rollers 120. This allows the medium discharge device 100 to transport the medium at a low speed while capturing an image of the medium, thereby reliably capturing an image of the medium, and to discharge the medium at a low speed when discharging the medium, thereby preventing the medium from flying out of the discharge tray 104 or scattering on the discharge tray 104.

[0122] Next, the control unit 151 waits until the rear end of the medium being discharged passes the position of the discharge rollers 120, similar to the process of step S120 in FIG. 6 (step S212).

[0123] Next, the control unit 151 returns the speed of the discharge roller 120 to the initial speed U1 or U1' (step S213), and ends the series of steps.

[0124] 8 and 9, time T8 indicates the time when the trailing edge of the medium passes the position of the discharge rollers 120. As shown in FIGS. 8 and 9, at time T8 when the trailing edge of the medium passes the position of the discharge rollers 120, the control unit 151 returns the speed of the conveying rollers 116 (discharge rollers 120) to the initial speed U1 or U1'.

[0125] Note that because the transport rollers 116 are driven by the third motor 133 shared with the discharge rollers 120, the speed of the transport rollers 116 does not return to its initial speed until the speed of the discharge rollers 120 returns to its initial speed, and the following medium should not be transported by the transport rollers 116. Therefore, the initial speed, final speed, discharge speed, and / or the timing of change thereof are set in advance for each roller so that the speed of the transport rollers 116 returns to its initial speed before the leading edge of the following medium passes the position of the transport rollers 116 (time T9 in FIGS. 8 and 9). By setting them in this manner, while the speed of the discharge rollers 120 is being changed, the leading edge of the following medium will not reach the position of the transport rollers 116, and the following medium will be fed by the feed rollers 112 and separation rollers 113. Therefore, even if the speed of the transport rollers 116, which are driven by the third motor 133 shared with the discharge rollers 120, changes together with the discharge rollers 120, the following medium will be fed without any problems.

[0126] In this way, the control unit 151 controls the discharge rollers 120 so as to reduce the speed of the discharge rollers 120 before the leading edge of the succeeding medium reaches the conveyance rollers 116. The medium discharge device 100 reduces the speed of the discharge rollers 120 before the succeeding medium reaches the conveyance rollers 116, which are driven by the same third motor 133 as the discharge rollers 120. This allows the conveyance rollers 116 to stably convey the succeeding medium at a speed equal to or higher than the feeding speed of the feed rollers 112, and the medium discharge device 100 can prevent jams and wrinkles from occurring in the medium. Furthermore, the conveyance rollers 116 can convey the medium at a constant speed at the imaging position, and the medium discharge device 100 can prevent distortion from occurring in the input image.

[0127] The control unit 151 may change the speed of the discharge rollers 120, the timing at which the change starts, and / or the period for which the change is made, depending on the amount of skew of the medium. For example, the smaller the amount of skew of the medium, the earlier the timing at which the change starts, the lower the speed of the discharge rollers 120, and / or the shorter the period for which the change is made. This allows the medium discharge device 100 to better prevent the medium from flying out of the discharge tray 104 or scattering on the discharge tray 104, the smaller the amount of skew of the medium. The control unit 151 may delay the timing at which the change starts, increase the speed of the discharge rollers 120, or lengthen the period for which the change is made, the smaller the amount of skew of the medium.

[0128] The control unit 151 may also change the speed of the discharge rollers 120, the timing at which the speed change begins, and / or the period for which the speed change begins, depending on the width of the medium. For example, the smaller the width of the medium, the earlier the timing at which the speed change begins, the lower the speed of the discharge rollers 120, and / or the shorter the period for which the speed change occurs. This allows the medium discharge device 100 to better prevent the medium from flying out of the discharge tray 104 or scattering on the discharge tray 104, the smaller the width of the medium. Note that the control unit 151 may also delay the timing at which the speed change begins, increase the speed of the discharge rollers 120, or lengthen the period for which the speed change occurs, the smaller the width of the medium.

[0129] Furthermore, the process of step S205 and / or the processes of steps S206 to S207 may be omitted. Furthermore, the processes of steps S204 and S208 may be omitted. In this case, either the process of step S209 or the process of step S210 is executed in a fixed manner.

[0130] In addition, in the flowcharts shown in Figures 6 and 7, when the trailing end of the preceding medium passes the first predetermined position (step S111), the feed roller 112 is rotated again (step S113) to feed the following medium, but the timing of feeding the medium may be other timing.

[0131] For example, when the speed of the discharge roller 120 returns to the initial speed, the control unit 151 may rotate the feed roller 112 again to feed the subsequent medium. The control unit 151 determines that the speed of the discharge roller 120 has returned to the initial speed when a through-up period has elapsed since the control unit 151 controlled the third motor 133 to return the speed of the discharge roller 120 to the initial speed.

[0132] FIG. 11 is a graph for explaining the change in speed of each roller when the feed roller is rotated again after the speed of the discharge roller has returned to the initial speed.

[0133] Figure 11 shows the change in speed of each roller when the resolution is equal to or less than the resolution threshold. In Figure 11, graph G31 shows the change in speed of the feed roller 112, and graph G32 shows the change in speed of the transport roller 116. The horizontal axis of each of graphs G31 and G32 indicates time, and the vertical axis indicates the transport speed of the medium by each roller. Meanwhile, graph G33 shows the change in signal value of the fourth medium signal. The horizontal axis of graph G33 indicates time, and the vertical axis indicates the signal value.

[0134] 11, time T5, at which the feed roller 112 is rotated again at the initial speed V1, is when the speed of the discharge roller 120 returns to the initial speed U1. When the speed of the discharge roller 120 returns to the initial speed U1, the control unit 151 rotates the feed roller 112 again at the initial speed V1 to feed the following medium. This allows the medium discharge device 100 to reliably prevent the following medium from colliding with the preceding medium, preventing jams and damage to the medium.

[0135] The control unit 151 may change the speed of the feed roller 112 to an initial speed V1 or V1' before the trailing end of the preceding medium passes the discharge roller 120, and then change the speed of the feed roller 112 to a final speed V2 or V2' when the speed of the discharge roller 120 returns to the initial speed.

[0136] FIG. 12 is a graph for explaining the change in speed of each roller when the speed of the discharge roller is changed to the final speed after the speed of the discharge roller has returned to the initial speed.

[0137] Figure 12 shows the change in speed of each roller when the resolution is equal to or less than the resolution threshold. In Figure 12, graph G41 shows the change in speed of the feed roller 112, and graph G42 shows the change in speed of the transport roller 116. The horizontal axis of each of graphs G41 and G42 indicates time, and the vertical axis indicates the transport speed of the medium by each roller. Meanwhile, graph G43 shows the change in signal value of the fourth medium signal. The horizontal axis of graph G43 indicates time, and the vertical axis indicates the signal value.

[0138] 12, time T10, at which the feed roller 112 is rotated at the final speed V2, is when the speed of the discharge roller 120 has returned to the initial speed. When the speed of the discharge roller 120 has returned to the initial speed, the control unit 151 sets the speed of the feed roller 112 to the final speed V2, thereby increasing the feed speed. This allows the medium discharge device 100 to reduce the time required for the medium transport process while preventing subsequent media from colliding with preceding media, thereby improving the productivity of input images.

[0139] 8 and 9, the medium ejection device 100 sets the speed of the feed roller 112 to the final speed V2 before the trailing edge of the preceding medium passes the position of the ejection roller 120. This allows the medium ejection device 100 to further reduce the time required for the medium transport process and further improve the productivity of input images.

[0140] As described above in detail, the medium ejection device 100 controls the ejection rollers 120 based on the detection result from the fourth medium sensor 118, which is disposed between the transport rollers 116 and the imaging device 119, and the amount of skew of the medium. This allows the medium ejection device 100 to control the ejection rollers 120 when it is estimated that imaging of the entire medium has been completed based on the position and amount of skew of the medium. Therefore, the medium ejection device 100 is able to properly eject the medium while properly performing the imaging process on the medium.

[0141] By transporting the medium at a constant speed from the start to the completion of medium reading, the medium ejection device 100 can maintain a constant relationship between the timing of medium reading by the imaging device 119 and the speed of the medium, thereby suppressing distortion (stretching or shrinking) of the input image. Furthermore, by changing the speed of the medium from the completion of medium reading to the completion of ejection, the medium ejection device 100 can improve the alignment of ejected media. Furthermore, by returning the speed of the medium before starting to read the next medium, the medium ejection device 100 can properly transport the next medium.

[0142] Because each motor rotates at the specified speed after a predetermined through-up or through-down period has elapsed since the speed change command was issued, it takes time to change the speed of each roller to the target speed. Generally, a distance of approximately 5 to 10 mm is required to change from a speed at which the imaging device can capture images to a speed at which the alignment of the ejected media can be ensured. On the other hand, in a medium ejection device with a straight-path media transport path, the distance between the imaging device and the ejection rollers is small, and the transport rollers and the ejection rollers are driven by a common motor to reduce the size, weight, and cost of the device. Therefore, if the media is being transported at an angle, there is likely to be insufficient time between the completion of imaging of the entire media and the change in the speed of the ejection rollers, and between the completion of media ejection and the start of transport of the next media. The medium ejection device 100 changes the speed of the ejection rollers 120 and the transport rollers 116, provided that the amount of skew of the media is equal to or less than the skew amount threshold. That is, when the skew amount of the medium is equal to or less than the skew amount threshold, even during overscanning, the medium discharge device 100 assumes that the rear end of the medium has passed the imaging position, and changes the speed of the discharge rollers 120 and the transport rollers 116. This enables the medium discharge device 100 to improve the alignment of the discharged media while suppressing increases in device size, weight, and cost.

[0143] Furthermore, the medium ejection device 100 controls the ejection rollers 120 using the detection results of the medium by the fourth medium sensor 118, which is essential for determining the timing of imaging by the imaging device 119. Because the medium ejection device 100 does not use a special sensor for controlling the ejection rollers 120, it is possible to control the ejection rollers 120 while suppressing increases in device size, weight, and cost.

[0144] Note that the medium discharge device 100 may control the discharge rollers 120 based on the rear end of the medium detected from the image generated by the imaging device 119, instead of the amount of skew of the medium. In this case, the control unit 151 detects the left and right edges of the medium from each line image acquired from the imaging device 119, as described in the processing of S203 in FIG. 10 . If the left and right edges are detected in the line image, the control unit 151 determines that the rear end of the medium has not yet passed the imaging position. On the other hand, if the state in which the left and right edges were detected in the line image changes to a state in which they are no longer detected, the control unit 151 determines that the rear end of the medium has passed the imaging position.

[0145] The medium discharge device 100 stores in advance in the storage device 140, as a roller area, an area in the line image that corresponds to the area where the imaging device 119 and the discharge roller 120 overlap when viewed from the medium discharge direction A1 (the area where the imaging device 119 and the discharge roller 120 overlap in the width direction A2). The control unit 151 determines that the trailing edge of the medium has passed the discharge roller 120 when a ninth predetermined time has elapsed since the area sandwiched between the detected left and right edges in the line image changed from being included in the roller area to being not included in the area. The ninth predetermined time is set to the time required for the medium to move from the imaging position of the imaging device 119 to the downstream end of the nip portion between the discharge roller 120 and the second opposing roller 121.

[0146] The control unit 151 changes the speed of the discharge rollers 120 if the rear end of the medium passes the imaging position before the rear end of the medium passes the discharge rollers 120. On the other hand, the control unit 151 does not change the speed of the discharge rollers 120 if the rear end of the medium does not pass the imaging position before the rear end of the medium passes the discharge rollers 120. This allows the medium discharge device 100 to properly discharge the medium while properly performing the imaging process on the medium, even if, for example, a tab or the like is attached to the rear end of the medium and the rear end of the medium does not have a linear shape.

[0147] FIG. 13 is a diagram illustrating a transport path inside a medium ejection device according to another embodiment.

[0148] The medium ejection device 200 according to this embodiment has the same components as the medium ejection device 100. However, the medium ejection device 200 has an image forming device 219 instead of the imaging device 119. In the medium ejection device 200, the image forming device 219 is disposed at a position corresponding to the position where the imaging device 119 is disposed within the medium ejection device 100.

[0149] The image forming device 219 is an example of a processing unit, and performs a predetermined process on the medium transported by the transport rollers 116. The image forming device 219 is an example of an image forming unit, and forms an image on the medium transported by the transport rollers 116 as the predetermined process. The image forming device 219 includes a first image forming device 219a and a second image forming device 219b that are arranged opposite each other across a medium transport path.

[0150] The first image forming device 219a prints predetermined information on the surface of the transported medium in accordance with control from the processing circuit 150. The predetermined information is information such as letters and numbers designated by a user using the operation device 105 or an information processing device (e.g., a personal computer, a mobile information terminal, etc.) not shown. The first image forming device 219a is an inkjet type printer and has a first printer head 219c formed with multiple ink ejection orifices, and prints predetermined information on the medium by ejecting ink onto the medium passing through a first image forming position P3 of the first image forming device 219a.

[0151] The second image forming device 219b prints predetermined information on the back side of the medium being transported in accordance with control from the processing circuit 150. The second image forming device 219b is an inkjet type printer, and has a second printer head 219d formed with a plurality of ink ejection orifices, and prints predetermined information on the medium by ejecting ink onto the medium passing through the second image forming position P4 of the second image forming device 219b.

[0152] It should be noted that the image forming device 219 may be a printer other than the inkjet type, such as a laser type.

[0153] Like the medium ejection device 100, the medium ejection device 200 executes the medium conveyance process shown in FIGS. 6 and 7 and the ejection control process shown in FIG. 10. However, in step S102 of FIG. 6, the profile includes a setting for the resolution of image formation by the image forming device 219. In step S103, the control unit 151 sets the speed of each roller lower as the resolution of image formation increases, and sets the speed of each roller higher as the resolution of image formation decreases. In step S110, the control unit 151 causes the image forming device 219 to start image formation on the medium when the leading edge of the medium reaches the image forming position of the image forming device 219. Also, in steps S117 and S119 of FIG. 7, the control unit 151 causes the image forming device 219 to stop image formation on the medium when the trailing edge of the medium passes the image forming position of the image forming device 219.

[0154] The control unit 151 controls the discharge rollers 120 based on the detection result of the fourth medium sensor 118 disposed between the transport rollers 116 and the image forming device 219 and the amount of skew of the medium. This allows the medium discharge device 200 to prevent distortion (stretching or shrinking) of the image formed on the medium caused by a change in the medium transport speed while the image forming device 219 is forming an image on the medium.

[0155] Furthermore, the control unit 151 reduces the speed of the discharge rollers 120 when the resolution in image formation is equal to or less than the resolution threshold. This allows the medium discharge device 100 to transport the medium at high speed before medium discharge to shorten the time required for the medium transport process, and to discharge the medium at low speed when discharging the medium, thereby preventing the medium from flying off the discharge tray 104 or scattering on the discharge tray 104. On the other hand, the control unit 151 increases the speed of the discharge rollers 120 when the resolution in image formation is greater than the resolution threshold. This allows the medium discharge device 100 to transport the medium at low speed during medium imaging to reliably form an image on the medium, and to discharge the medium at high speed when discharging the medium, thereby preventing the medium from remaining around the discharge port and causing a media jam. Alternatively, the control unit 151 does not change the speed of the discharge rollers 120 when the resolution in image formation is greater than the resolution threshold. As a result, the medium ejection device 100 transports the medium at a slow speed during medium imaging to reliably form an image on the medium, and ejects the medium at a slow speed when ejecting the medium, thereby preventing the medium from flying out of the ejection table 104 or scattering on the ejection table 104.

[0156] As described above in detail, medium discharge device 200 controls discharge rollers 120 based on the detection result from fourth medium sensor 118, which is disposed between conveyance rollers 116 and image forming device 219, and the amount of skew of the medium. This allows medium discharge device 200 to control discharge rollers 120 when it is estimated that image formation on the medium is complete based on the position and amount of skew of the medium. Therefore, medium discharge device 200 is able to properly discharge the medium while properly performing image formation processing on the medium.

[0157] FIG. 14 is a diagram showing a schematic configuration of a processing circuit in a medium ejection device according to another embodiment.

[0158] The processing circuit 350 is used in place of the processing circuit 150 of the medium discharge device 100 or the medium discharge device 200, and executes the medium transport process, discharge control process, and the like in place of the processing circuit 150. The processing circuit 350 includes a control circuit 351, a skew amount detection circuit 352, a width detection circuit 353, and the like. Note that each of these components may be configured as an independent integrated circuit, microprocessor, firmware, or the like.

[0159] The control circuit 351 is an example of a control unit and has the same functions as the control unit 151. The control circuit 351 receives an operation signal from the operation device 105 or the interface device 134, a first medium signal from the first medium sensor 111, a second medium signal from the second medium sensor 114, a third medium signal from the third medium sensor 115, and a fourth medium signal from the fourth medium sensor 118, and reads the amount of skew and the width of the medium from the storage device 140. The control circuit 351 controls the first motor 131, the second motor 132, and the third motor 133 based on the acquired information. The control circuit 351 acquires a line image from the imaging device 119 and stores it in the storage device 140, and also generates an input image and outputs it to the interface device 134. Alternatively, the control circuit 351 causes the image forming device 219 to form an image on the medium.

[0160] The skew amount detection circuit 352 is an example of a skew amount detection unit, and has the same function as the skew amount detection unit 152. The skew amount detection circuit 352 receives a second medium signal from the second medium sensor 114 and a third medium signal from the third medium sensor 115, or reads a line image from the storage device 140. The skew amount detection circuit 352 detects the amount of skew of the medium from the acquired information and stores it in the storage device 140.

[0161] The width detection circuit 353 is an example of a width detection unit, and has the same function as the width detection unit 153. The width detection circuit 353 reads a line image from the storage device 140. The width detection circuit 353 detects the width of the medium from the line image and stores it in the storage device 140.

[0162] As described above in detail, even when the processing circuit 350 is used, the medium ejection device is able to properly eject the medium while properly executing the predetermined processing on the medium.

[0163] Although the above has described preferred embodiments, the embodiments are not limited thereto. For example, the medium transport path of the medium ejection device may have a so-called U-turn path mechanism, which feeds and transports the media placed on the loading tray from the top to the bottom and ejects them onto the ejection tray. In this case, the separation roller is positioned below the feed roller and faces the feed roller. [Explanation of symbols]

[0164] 100 medium discharge device, 114 second medium sensor, 115 third medium sensor, 116 transport roller, 118 fourth medium sensor, 119 imaging device, 120 discharge roller, 133 third motor, 151 control unit, 152 skew amount detection unit, 153 width detection unit, 219 image forming apparatus

Claims

1. a conveying roller for conveying the medium; a processing unit that performs a predetermined process on the medium conveyed by the conveyance roller; a discharge roller disposed downstream of the processing section in the medium transport direction, for discharging the medium processed by the processing section; a motor that drives the conveying roller and the discharge roller; a medium detection unit disposed between the transport roller and the processing unit and configured to detect a medium; a skew amount detection unit that detects the amount of skew of the medium; a control unit that controls the discharge rollers before the trailing edge of the medium passes through the discharge rollers based on the detection result by the medium detection unit and the amount of skew; A medium ejection device comprising:

2. The medium ejection device according to claim 1 , wherein the processing unit is an imaging unit that captures an image of the medium transported by the transport roller as the predetermined process.

3. The medium ejection device according to claim 1 , wherein the processing section is an image forming section that forms an image on the medium transported by the transport roller as the predetermined process.

4. The medium ejection device according to claim 2 , wherein the skew amount detection unit detects the skew amount based on an image generated by the imaging unit.

5. The printer further includes a plurality of second medium detectors arranged at intervals in a direction intersecting the medium transport direction, 5. The medium ejection device according to claim 1, wherein the skew amount detection unit detects the amount of skew based on detection results from the plurality of second medium detection units.

6. 5. The medium discharging device according to claim 1, wherein the control unit changes the speed of the discharge rollers when the skew amount is equal to or less than a skew amount threshold.

7. The medium ejection device according to claim 2, wherein the control unit reduces the speed of the ejection roller when the resolution of the image captured by the imaging unit is equal to or less than a resolution threshold, and does not change or increases the speed of the ejection roller when the resolution is greater than the resolution threshold.

8. The medium ejection device according to claim 3, wherein the control unit reduces the speed of the ejection roller when the resolution of the image formed by the image forming unit is equal to or less than a resolution threshold, and does not change or increases the speed of the ejection roller when the resolution is greater than the resolution threshold.

9. A medium discharge device described in any one of claims 1 to 4, wherein the control unit controls the discharge rollers to change the speed of the discharge rollers before the trailing end of the medium passes through the discharge rollers, and to return the speed of the discharge rollers to their original speed before the leading end of the following medium reaches the transport rollers.

10. Further, a width detection unit is provided to detect the width of the medium.

5. The medium ejection device according to claim 1, wherein the control unit controls the ejection rollers further based on the width.

11. 5. The medium ejection device according to claim 1, wherein a distance between the transport roller and the ejection roller in the medium ejection direction is shorter than a minimum medium length supported by the medium ejection device.

12. The medium is transported by the transport roller, a processing unit that performs a predetermined process on the medium conveyed by the conveyance roller; a discharge roller disposed downstream of the processing section in a medium transport direction, the medium having been processed by the processing section being discharged; a motor driving the conveying roller and the discharge roller; detecting the medium by a medium detection unit disposed between the conveyance roller and the processing unit; Detects the amount of skew of the media, and controlling the discharge rollers before the trailing edge of the medium passes through the discharge rollers based on the detection result of the medium and the amount of skew. A medium ejection method comprising:

13. A control program for a medium discharge device having a transport roller that transports a medium, a processing unit that performs a predetermined process on the medium transported by the transport roller, a discharge roller that is disposed downstream of the processing unit in the medium transport direction and that discharges the medium processed by the processing unit, a motor that drives the transport roller and the discharge roller, and a medium detection unit that is disposed between the transport roller and the processing unit and that detects the medium, Detects the amount of skew of the media, and controlling the discharge rollers before the trailing edge of the medium passes through the discharge rollers based on the detection result of the medium and the amount of skew. a control program for causing the medium ejection device to execute the above steps;

Images