JP2024037026A - Medium conveyance device, medium conveyance method and control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medium conveyance device, medium conveyance method and control program which can properly correct a skew of a medium while suppressing increase in a device cost.

SOLUTION: A medium conveyance device comprises: a conveyance roller; a plurality of detection sensors which are arranged with a gap in the direction orthogonal to the medium conveyance direction; a detection unit which detects the size and inclination of a medium on the basis of the detection result by the plurality of detection sensors; and a control unit which executes skew correction of the medium. The control unit, in a case where the size of the medium is equal to or less than a size threshold, executes skew correction of the medium when the inclination of the medium is equal to or greater than an inclination threshold, and does not execute skew correction of the medium when the inclination of the medium is equal to or less than the inclination threshold.

SELECTED DRAWING: Figure 6

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present disclosure relates to a medium transport device, a medium transport method, and a control program, and particularly relates to a medium transport device, a medium transport method, and a control program that perform skew correction of a medium.

In media transport devices such as scanners, when the medium is transported and read, skew (skewing) occurs, where the medium is transported at an angle, and the entire medium may not be imaged, or the medium may collide with the side wall of the transport path. This may cause a media jam (paper jam). Therefore, in a media transport device, it is desired to correct the skew of the medium when it occurs, but correcting the skew of the medium places a load on the medium and causes damage to the medium. there is a possibility.

A sheet conveying device is disclosed that includes a size detection unit that detects the size of a sheet, and a skew determination unit that determines a skewed state of the sheet based on a determination criterion determined according to the detection result of the size detection unit. (See Patent Document 1).

Japanese Patent Application Publication No. 2018-27851

Media transport devices are required to appropriately correct media skew while suppressing increases in device costs.

An object of the present invention is to provide a medium transport device, a medium transport method, and a control program that can appropriately correct the skew of a medium while suppressing an increase in device cost.

A medium conveyance device according to one aspect of the embodiment includes a conveyance roller, a plurality of detection sensors arranged at intervals in a direction perpendicular to a medium conveyance direction, and a detection result of a medium based on detection results from the plurality of detection sensors. It has a detection unit that detects the size and tilt, and a control unit that performs skew correction of the medium, and the control unit is configured to perform skew correction when the size of the medium is less than or equal to the size threshold, and when the tilt of the medium is larger than the tilt threshold. Skew correction of the medium is performed, and when the slope of the medium is less than or equal to the slope threshold, the skew correction of the medium is not performed.

A medium conveyance method according to one aspect of the embodiment conveys a medium using a conveyance roller, and determines the size and size of the medium based on detection results by a plurality of detection sensors arranged at intervals in a direction perpendicular to the medium conveyance direction. detecting the skew and performing skew correction of the medium, in performing the skew correction, if the size of the medium is less than or equal to a size threshold, performing the skew correction of the medium when the skew of the medium is greater than the skew threshold; , when the tilt of the medium is less than or equal to the tilt threshold, skew correction of the medium is not performed.

A control program according to one aspect of the embodiment is a control program for a medium conveyance device having a conveyance roller and a plurality of detection sensors arranged at intervals in a direction perpendicular to a medium conveyance direction, the control program including a plurality of detection sensors. Detecting the size and inclination of the medium based on the detection result by the detection sensor, and causing the medium transport device to perform skew correction of the medium, and in executing the skew correction, if the size of the medium is equal to or less than a size threshold; , when the slope of the medium is greater than the slope threshold, the medium skew correction is performed, and when the medium slope is less than or equal to the slope threshold, the medium skew correction is not performed.

According to the present invention, the medium transport device, the medium transport method, and the control program can appropriately correct the skew of the medium while suppressing an increase in device cost.

FIG. 1 is a perspective view showing a medium transport device 100 according to an embodiment. FIG. 3 is a diagram for explaining a conveyance path inside the medium conveyance device 100. FIG. FIG. 3 is a schematic diagram for explaining each detection sensor. 1 is a block diagram showing a schematic configuration of a medium transport device 100. FIG. 2 is a diagram showing a schematic configuration of a storage device 140 and a processing circuit 150. FIG. 3 is a flowchart illustrating an example of the operation of a medium reading process. (A) and (B) show how media M1 and M2 are being transported. It shows how the medium M3 is being transported. (A) and (B) show how media M4 and M5 are being transported. FIG. 3 is a schematic diagram for explaining an example of a slope threshold value. 3 is a diagram showing a schematic configuration of another processing circuit 250. FIG.

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

FIG. 1 is a perspective view of a media transport device 100 configured as an image scanner. The medium transport device 100 feeds and transports a medium, which is a document, and images the medium. The medium is paper, thin paper, cardboard, card, booklet, or the like. The medium transport device 100 may be a facsimile, a copying machine, a multifunction peripheral (MFP), or the like. Note that the medium to be conveyed may be an object to be printed instead of a document, and the medium conveying device 100 may be a printer or the like.

The medium transport device 100 includes a lower housing 101, an upper housing 102, a mounting table 103, a discharge table 104, an operating device 105, a display device 106, and the like. In FIG. 1, arrow A1 indicates the medium transport direction, arrow A2 indicates the width direction perpendicular to the medium transport direction, and arrow A3 indicates the height direction perpendicular to the medium transport path. In the following, upstream refers to upstream in the medium transport direction A1, and downstream refers to downstream in the medium transport direction A1.

The upper casing 102 is disposed at a position covering the upper surface of the medium transport device 100, and is engaged with the lower casing 101 by a hinge so that it can be opened and closed when a medium becomes clogged or when cleaning the inside of the medium transport device 100. There is.

The mounting table 103 engages with the lower housing 101 and places the medium to be fed and transported. On the mounting table 103, two side guides 103a are arranged side by side with an interval in the width direction A2. Each side guide 103a is provided on the mounting surface of the mounting table 103 so as to be movable in conjunction with each other in the width direction A2. The side guide 103a is positioned by the user according to the width of the medium placed on the mounting table 103, and regulates the width direction of the medium. By positioning the ends of the medium in the width direction A2 by the two side guides 103a, the medium placed on the mounting table 103 is placed at the center position in the width direction A2. That is, in the width direction A2, the center position of the medium is arranged at the center position of the mounting table 103, and the center position of the fed and conveyed medium is arranged at the center position of the medium transport path.

The ejection table 104 engages with the upper housing 102 and places the ejected medium thereon. Note that the ejection table 104 may be engaged with the lower housing 101.

The operating device 105 includes an input device such as a button and an interface circuit that obtains a signal from the input device, receives an input operation by a user, and outputs an operation signal according to the input operation by the user. The display device 106 has a display including a liquid crystal, an organic EL (Electro-Luminescence), etc., and an interface circuit that outputs image data to the display, and displays the image data on the display.

FIG. 2 is a diagram for explaining the transport path inside the medium transport device 100.

The conveyance path inside the medium conveyance device 100 includes a first medium sensor 111, a plurality of feeding rollers 112, a plurality of separation rollers 113, a first detection sensor 114, a second detection sensor 115, a third detection sensor 116, and a fourth detection sensor. Sensor 117 , fifth detection sensor 118 , multiple first conveyance rollers 119 , multiple first driven rollers 120 , second medium sensor 121 , imaging device 122 , multiple second conveyance rollers 123 , and multiple second driven rollers 124 etc.

The plurality of feeding rollers 112, separation rollers 113, first conveying rollers 119, first driven rollers 120, second conveying rollers 123 and/or second driven rollers 124 are arranged at intervals in the width direction A2 perpendicular to the medium conveying direction. They are arranged side by side with space between them. The number of each of the feeding roller 112, the separating roller 113, the first conveying roller 119, the first driven roller 120, the second conveying roller 123, and/or the second driven roller 124 is two, for example. Note that the number of each roller is not limited to two, and may be one or three or more.

The upper surface of the lower casing 101 forms a lower guide 101a for the medium transport path, and the lower surface of the upper casing 102 forms an upper guide 102a for the medium transport path. The medium transport device 100 has a so-called straight path, and sequentially feeds and transports the medium placed on the mounting table 103 from the bottom, and discharges the medium onto the discharge table 104 .

The first medium sensor 111 is arranged upstream of the feeding roller 112 and separation roller 113. The first medium sensor 111 includes a contact detection sensor and detects whether a medium is placed on the mounting table 103. The first medium sensor 111 generates and outputs a first medium signal whose signal value changes depending on whether a medium is placed on the mounting table 103 or not. Note that the first medium sensor 111 is not limited to a contact detection sensor, and any other sensor capable of detecting the presence or absence of a medium, such as a photodetection sensor, may be used as the first medium sensor 111.

The multiple feeding rollers 112 are an example of multiple conveying rollers. The feeding roller 112 is provided in the lower housing 101. The feeding roller 112 is rotatably provided in the medium feeding direction A4, and sequentially separates, feeds and conveys a plurality of media placed on the mounting table 103 from the bottom. Each feeding roller 112 is provided to be independently rotated by a separate motor. Each feeding roller 112 may be provided so as to be rotated together by a common motor. 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 feeding roller 112. The separation roller 113 is provided rotatably or stopably in a direction A5 opposite to the medium feeding direction.

The first conveyance roller 119 and the first driven roller 120 are arranged downstream of the feed roller 112 and the separation roller 113 in the medium conveyance direction A1, facing each other. The first conveying roller 119 is provided in the upper housing 102 and conveys the medium fed by the feeding roller 112 and separation roller 113 to the imaging device 122. The first conveyance rollers 119 are provided so as to be rotated together by a common motor. Each of the first conveyance rollers 119 may be provided to be rotated independently by a separate motor. The first conveyance roller 119 may be provided in the lower casing 101 and the first driven roller 120 may be provided in the upper casing 102. Further, the first driven roller 120 may also be provided to be driven by a driving force from a motor. In that case, each first driven roller 120 is provided so as to be rotated together by a common motor. Each of the first driven rollers 120 may be provided to be rotated independently by a separate motor.

The imaging device 122 is disposed downstream of the first conveyance roller 119 and upstream of the second conveyance roller 123 in the medium conveyance direction A1, and captures the medium conveyed by the first conveyance roller 119 and the first driven roller 120. Take an image. The imaging device 122 includes a first imaging device 122a and a second imaging device 122b that are arranged to face each other across a medium transport path.

The first imaging device 122a has a line sensor using a CIS (Contact Image Sensor) of the same magnification optical system type and having imaging elements using CMOS (Complementary Metal Oxide Semiconductor) arranged linearly in the main scanning direction. Further, the first imaging device 122a includes a lens that forms an image on the imaging device, and an A/D converter that amplifies the electrical signal output from the imaging device and performs analog/digital (A/D) conversion. The first imaging device 122a images the surface of the medium being conveyed, generates an input image, and outputs the image under control from a processing circuit described later.

Similarly, the second imaging device 122b has a CIS line sensor of a same-magnification optical system type having CMOS imaging elements linearly arranged in the main scanning direction. Further, the second imaging device 122b includes a lens that forms an image on the imaging device, and an A/D converter that amplifies the electrical signal output from the imaging device and performs analog/digital (A/D) conversion. The second imaging device 122b images the back side of the medium being conveyed, generates an input image, and outputs the image under control from a processing circuit described later.

Note that the imaging device 122 may have only one of the first imaging device 122a and the second imaging device 122b, and may read only one side of the medium. Further, instead of a line sensor using a CIS of a 1x optical system type including a CMOS image sensor, a line sensor using a CIS of a 1x optical system type including an image sensor using a CCD (Charge Coupled Device) may be used. Further, a reduction optical system type line sensor including a CMOS or CCD image sensor may be used.

The second conveyance roller 123 and the second driven roller 124 are arranged facing each other downstream from the imaging device 122 in the medium conveyance direction A1, that is, from the first conveyance roller 119 and the first driven roller 120. The second conveyance roller 123 is provided in the upper housing 102 and conveys the medium conveyed by the first conveyance roller 119 and the first driven roller 120 further downstream, and discharges it onto the discharge table 104 . The second conveyance rollers 123 are provided so as to be rotated together by a common motor. Each of the second conveyance rollers 123 may be provided to be rotated independently by a separate motor. The second conveyance roller 123 may be provided in the lower case 101 and the second driven roller 124 may be provided in the upper case 102. Further, the second driven roller 124 may also be provided to be driven by a driving force from a motor. In that case, each second driven roller 124 is provided so as to be rotated together by a common motor. Each of the second driven rollers 124 may be provided to be rotated independently by a separate motor.

The medium placed on the mounting table 103 is conveyed between the lower guide 101a and the upper guide 102a in the medium conveying direction A1 as the feeding roller 112 rotates in the medium conveying direction A4. The medium transport device 100 has two feeding modes: a separation mode in which the medium is fed while separating it, and a non-separation mode in which the medium is fed without separating it. The feeding mode is set by the user using the operating device 105 or an information processing device that is communicatively connected to the medium transport device 100. When the feeding mode is set to the separation mode, the separation roller 113 rotates or stops in the direction A5 opposite to the medium feeding direction. Due to the action of the feeding roller 112 and separation roller 113, when a plurality of media are placed on the mounting table 103, only the medium that is in contact with the feeding roller 112 among the media placed on the mounting table 103 is removed. are separated. This restricts the conveyance of media other than the separated media (prevention of double feeding). On the other hand, when the feeding mode is set to non-separation mode, the separation roller 113 rotates in the medium feeding direction (the opposite direction of arrow A5).

The medium is fed between the first conveyance roller 119 and the first driven roller 120 while being guided by the lower guide 101a and the upper guide 102a. The first conveyance roller 119 and the first driven roller 120 rotate in the directions of arrows A6 and A7, respectively, and are sent between the first imaging device 122a and the second imaging device 122b. The medium read by the imaging device 122 is discharged onto the discharge table 104 by the rotation of the second conveyance roller 123 and the second driven roller 124 in the directions of arrows A8 and A9, respectively.

FIG. 3 is a schematic diagram for explaining each detection sensor and the second medium sensor 121. FIG. 3 is a schematic diagram of the lower casing 101 viewed from above with the upper casing 102 opened. Below, the first detection sensor 114, the second detection sensor 115, the third detection sensor 116, the fourth detection sensor 117, and the fifth detection sensor 118 may be collectively referred to as a plurality of detection sensors.

As shown in FIG. 3, the plurality of detection sensors are arranged downstream of the feeding roller 112 and separating roller 113 and upstream of the first conveying roller 119 and first driven roller 120 in the medium conveying direction A1. Further, the plurality of detection sensors are arranged side by side at intervals in the width direction A2 perpendicular to the medium conveyance direction. The plurality of detection sensors are arranged such that the distances from each of the plurality of detection sensors to the center position C are different between one side and the other side of the center position C in the width direction A2 perpendicular to the medium conveyance direction. will be placed in

The first detection sensor 114 is arranged at the center in the width direction A2. The first detection sensor 114 is located between the inner edges of the plurality of feeding rollers 112 in the width direction A2, between the inner edges of the plurality of first conveyance rollers 119, and/or between the inner edges of the plurality of second conveyance rollers 123. located between the inner ends. In particular, the first detection sensor 114 is arranged at a position equidistant from the two side walls W arranged at both ends of the medium transport path in the width direction A2. A position that is equidistant from the two side walls W in the width direction A2 is an example of a center position C in the width direction A2 orthogonal to the medium conveyance direction.

The second detection sensor 115 is an example of the first sensor. The second detection sensor 115 is located outside the first detection sensor 114 in the width direction A2, particularly at the inner end of each feeding roller 112, the inner end of each first conveyance roller 119, and the inner side of the second conveyance roller 123. It is placed outside the end. The second detection sensor 115 is arranged on one side (the right side in the example of FIG. 3) with respect to the center position C in the width direction A2, and spaced apart from the center position C by a first distance D1. The first distance D1 is smaller than 1/2 of the width E1 of the maximum size medium supported by the medium transport device 100, and is smaller than 1/2 of the width E2 of the medium of a predetermined first standard size smaller than the maximum size. set to a large distance. The maximum size is, for example, A4 size, and the first standard size is, for example, A5 size. When the maximum size is A4 size and the first standard size is A5 size, width E1 is 210 mm, width E2 is 148 mm, and first distance D1 is a distance smaller than 105 mm and larger than 74 mm (e.g. 89.5mm).

The third detection sensor 116 is an example of a second sensor. The third detection sensor 116 is located outside the first detection sensor 114 in the width direction A2, particularly at the inner end of each feeding roller 112, the inner end of each first conveyance roller 119, and the inner side of the second conveyance roller 123. It is placed outside the end. The third detection sensor 116 is located on the opposite side of the second detection sensor 115 in the width direction A2, that is, on the other side (the left side in the example of FIG. 3) with respect to the center position C, from the first distance D1 from the center position C. They are spaced apart by a small second distance D2. The second distance D2 is smaller than 1/2 of the width E2 of the medium of the first standard size and larger than 1/2 of the width E3 of the medium of the predetermined second standard size smaller than the first standard size. set to distance. The second standard size is, for example, A6 size. When the first standard size is A5 size and the second standard size is A6 size, width E2 is 148 mm, width E3 is 105 mm, and second distance D2 is smaller than 74 mm and 52.5 mm. The distance is set to a larger distance (for example, 63.25 mm).

The fourth detection sensor 117 is an example of a third sensor. The fourth detection sensor 117 is located outside the first detection sensor 114 in the width direction A2, particularly at the inner end of each feeding roller 112, the inner end of each first conveyance roller 119, and the inner side of the second conveyance roller 123. It is placed outside the end. The fourth detection sensor 117 is located on the same side as the second detection sensor 115 in the width direction A2, that is, on one side (the right side in the example of FIG. 3) with respect to the center position C, and is located at a distance smaller than the second distance D2 from the center position C. They are spaced apart by a third distance D3. The third distance D3 is smaller than 1/2 of the width E3 of the medium of the size of the second standard, and larger than 1/2 of the width E4 of the medium of the predetermined size of the third standard, which is smaller than the size of the second standard. set to distance. The size of the third standard is, for example, A7 size. When the second standard size is A6 size and the third standard size is A7 size, width E3 is 105 mm, width E4 is 74 mm, and third distance D3 is smaller than 52.5 mm and 37 mm. The distance is set to a larger distance (for example, 44.8 mm).

The fifth detection sensor 118 is located outside the first detection sensor 114 in the width direction A2, particularly at the inner end of each feeding roller 112, the inner end of each first conveyance roller 119, and the inner side of the second conveyance roller 123. It is placed outside the end. The fifth detection sensor 118 is located on the opposite side of the second detection sensor 115 in the width direction A2, that is, on the other side (the left side in the example of FIG. 3) with respect to the center position C, and from a third distance D3 from the center position C. They are spaced apart by a small fourth distance D4. The fourth distance D4 is smaller than 1/2 of the width E4 of the medium of the size of the third standard, and larger than 1/2 of the width E5 of the medium of the predetermined size of the fourth standard, which is smaller than the size of the third standard. set to distance. The size of the fourth standard is, for example, A8 size. When the size of the third standard is A7 size and the size of the fourth standard is A8 size, width E4 is 74 mm, width E4 is 52 mm, and fourth distance D4 is smaller than 37 mm and larger than 26 mm. The distance is set to (for example, 31.75 mm).

Each detection sensor detects the medium conveyed to that position. Each detection sensor includes a light emitter and a light receiver provided on one side with respect to the medium transport path, and a light guide tube provided at a position facing the light emitter and the light receiver across the medium transport path. . The light emitting device is an LED (Light Emitting Diode) or the like, and emits light toward the medium transport path. On the other hand, the light receiver is a photodiode or the like, and receives the light emitted by the light emitter and guided by the light guide tube. When a medium exists at a position facing each detection sensor, the light emitted from the light emitter is blocked by the medium, so the light receiver does not detect the light emitted from the light emitter. Each detection sensor generates and outputs a detection signal whose signal value changes depending on whether a medium is present or absent at the position of each detection sensor, based on the intensity of light received by the light receiver.

Note that a reflective member such as a mirror may be used instead of the light guide tube. Further, the light emitter and the light receiver may be provided facing each other with the medium transport path in between. Further, each detection sensor may detect the presence of the medium using a contact detection sensor or the like that flows a predetermined current when the medium is in contact with the medium or when the medium is not in contact with the medium.

The second medium sensor 121 is arranged downstream of the first conveyance roller 119 and first driven roller 120 and upstream of the imaging device 122 in the medium conveyance direction A1. The second medium sensor 121 is located at the center in the width direction A2, particularly between the inner edges of the plurality of feeding rollers 112, between the inner edges of the plurality of first conveyance rollers 119, and/or between the plurality of second It is arranged between the inner ends of the conveying rollers 123. The second medium sensor 121 detects the medium conveyed to that position. The second medium sensor 121 includes a light emitter and a light receiver provided on one side with respect to the medium transport path, and a light guide tube provided at a position facing the light emitter and the light receiver across the medium transport path. including. The light emitter is an LED or the like, and emits light toward the medium transport path. On the other hand, the light receiver is a photodiode or the like, and receives the light emitted by the light emitter and guided by the light guide tube. The second medium sensor 121 generates a second medium signal whose signal value changes depending on whether the medium is present at the position of the second medium sensor 121 or not, based on the intensity of the light received by the light receiver. and output it.

Note that a reflective member such as a mirror may be used instead of the light guide tube. Further, the light emitter and the light receiver may be provided facing each other with the medium transport path in between. Further, the second medium sensor 121 may detect the presence of the medium using a contact detection sensor or the like that flows a predetermined current when the medium is in contact or not in contact with the medium.

FIG. 4 is a block diagram showing a schematic configuration of the medium transport device 100.

In addition to the above-described configuration, the medium transport device 100 further includes a motor 131, an interface device 132, a storage device 140, a processing circuit 150, and the like.

Motor 131 includes one or more motors. The motor 131 rotates the feeding roller 112 , the separating roller 113 , the first conveying roller 119 , the first driven roller 120 , the second conveying roller 123 , and/or the second driven roller 124 in response to a control signal from the processing circuit 150 . to feed, separate and transport the media. Motor 131 includes a separate motor that rotates each feed roller 112 independently. Motor 131 may include a separate motor that independently rotates each first transport roller 119, each first driven roller 120, each second transport roller 123, and/or each second driven roller 124.

The interface device 132 has an interface circuit similar to a serial bus such as a USB, and is electrically connected to an information processing device (for example, a personal computer, a mobile information terminal, etc.) (not shown) to transmit input images and various information. Send and receive. Further, instead of the interface device 132, a communication unit having an antenna for transmitting and receiving wireless signals and a wireless communication interface device for transmitting and receiving signals through a wireless communication line according to a predetermined communication protocol may be used. The predetermined communication protocol is, for example, a wireless LAN (Local Area Network). The communication unit may include a wired communication interface device for transmitting and receiving signals through a wired communication line according to a communication protocol such as a wired LAN.

The 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 an optical disk. Further, the storage device 140 stores computer programs, databases, tables, etc. used for various processes of the medium transport device 100. The computer program may be installed in the storage device 140 from a computer-readable portable recording medium using a known setup program or the like. The portable recording medium is, for example, a CD-ROM (compact disc read only memory), a DVD-ROM (digital versatile disc read only memory), or the like.

The processing circuit 150 operates based on a program stored in the storage device 140 in advance. The processing circuit is, for example, a CPU (Central Processing Unit). As the processing circuit 150, a DSP (digital signal processor), an LSI (large scale integration), an ASIC (application specific integrated circuit), an FPGA (field-programmable gate array), or the like may be used.

The processing circuit 150 includes an operating device 105, a display device 106, a first medium sensor 111, a first detection sensor 114, a second detection sensor 115, a third detection sensor 116, a fourth detection sensor 117, a fifth detection sensor 118, and a third detection sensor 116. It is connected to the two-medium sensor 121, the imaging device 122, the motor 131, the interface device 132, the storage device 140, etc., and controls each of these parts. The processing circuit 150 performs drive control of each motor, imaging control of the imaging device 122, etc. based on each medium signal received from each medium sensor. The processing circuit 150 acquires an input image from the imaging device 122 and transmits it to the information processing device via the interface device 132. Furthermore, the processing circuit 150 detects the size and inclination of the medium based on the detection signals received from each detection sensor, and controls the motor 131 to correct the skew of the medium based on the detection results.

FIG. 5 is a diagram showing a schematic configuration of the storage device 140 and the processing circuit 150.

As shown in FIG. 5, the storage device 140 stores a control program 141, a detection program 142, 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 according to each read program. Thereby, the processing circuit 150 functions as a control section 151 and a detection section 152.

FIG. 6 is a flowchart illustrating an example of the operation of the medium reading process of the medium transport device 100.

Hereinafter, an example of the operation of the medium reading process of the medium transport device 100 will be described with reference to the flowchart shown in FIG. Note that the operation flow described below is mainly executed by the processing circuit 150 in cooperation with each element of the medium transport device 100 based on a program stored in the storage device 140 in advance.

First, a user inputs an instruction to read a medium using the operating device 105 or the information processing device, and the control unit 151 receives an operation signal instructing to read the medium from the operating device 105 or the interface device 132. (Step S101).

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

On the other hand, when a medium is placed on the mounting table 103, the control unit 151 drives the motor 131. As a result, the control unit 151 rotates the feeding roller 112, separation roller 113, first conveyance roller 119, first driven roller 120, second conveyance roller 123, and/or second driven roller 124 to feed the medium. , separated and transported (step S103).

Next, the detection unit 152 waits until the leading edge of the fed medium passes the position of any detection sensor (step S104). The detection unit 152 periodically acquires each detection signal from each detection sensor, and when the signal value of each detection signal changes from a value indicating that a medium is not present to a value indicating that a medium is present, It is determined that the leading edge of the medium has passed the position of the detection sensor that outputs the detection signal.

Next, the detection unit 152 detects the size of the fed medium (step S105). The detection unit 152 detects the size of the medium based on detection signals obtained from a plurality of detection sensors. The detection unit 152 periodically acquires each detection signal from each detection sensor (first detection sensor 114, second detection sensor 115, third detection sensor 116, fourth detection sensor 117, and fifth detection sensor 118). The detection unit 152 detects that when the signal value of each detection signal changes from a value indicating that the medium is not present to a value indicating that the medium is present, the leading edge of the medium is detected by the detection sensor that outputs the detection signal. It is determined that the detection sensor has detected the leading edge of the medium. The detection unit 152 identifies the detection sensor that first detects the leading edge of the medium among all the detection sensors as the first detection sensor. The detection unit 152 identifies a detection sensor that has detected the leading edge of the medium within a predetermined time after the earliest detection sensor detects the leading edge of the medium, as a subsequent detection sensor.

The predetermined time is set to the time from when the leading edge of the medium passes the position of the first detection sensor until it reaches the nip position between the first conveyance roller 119 and the first driven roller 120. That is, for a predetermined period of time, the distance between each detection sensor in the medium conveyance direction A1 and the upstream end of the nip position of the first conveyance roller 119 and the first driven roller 120 is It is set to the value divided by the speed (peripheral speed). As described later, the control unit 151 corrects the skew of the medium by making the circumferential speeds of the plurality of feeding rollers 112 different from each other. After the leading edge of the medium reaches the nip position between the first conveying roller 119 and the first driven roller 120, it is held between the first conveying roller 119 and the first driven roller 120, so if the skew of the medium is corrected at that time, The media may be overloaded and damage may occur. The detection unit 152 specifies the subsequent detection sensor and the size of the medium within a predetermined time period in which the skew of the medium can be corrected appropriately, so that the control unit 151 appropriately determines whether or not to correct the skew of the medium. can be determined.

As described above, the medium placed on the mounting table 103 is positioned by the side guides 103a, and the center position of the medium in the width direction A2 is located at the center position C of the medium transport path. Therefore, when the first detection sensor or the subsequent detection sensor includes the second detection sensor 115 corresponding to an A4 size medium, the detection unit 152 determines that the size of the medium is A4 size. When the first detection sensor or the subsequent detection sensor does not include the second detection sensor 115 and includes the third detection sensor 116 that corresponds to an A5 size medium, the detection unit 152 determines that the size of the medium is A5 size. judge. When the first detection sensor or the subsequent detection sensor does not include the second to third detection sensors 115 to 116 and includes the fourth detection sensor 117 that corresponds to an A6 size medium, the detection unit 152 detects the size of the medium. It is determined that the size is A6. When the first detection sensor or the subsequent detection sensor does not include the second to fourth detection sensors 115 to 117 and includes the fifth detection sensor 118 that corresponds to an A7 size medium, the detection unit 152 detects the size of the medium. It is determined that the size is A7. When the first detection sensor or the subsequent detection sensor does not include the second to fifth detection sensors 115 to 118 and includes the first detection sensor 114 arranged at the center position, the detection unit 152 detects that the size of the medium is A8. It is determined that the size is smaller than the specified size.

Thereby, the medium transport device 100 can easily detect the size of the medium without performing complicated arithmetic processing. Further, in the medium transport device 100, each detection sensor corresponding to each medium size is arranged only on one side with respect to the center position C, so the medium transport device 100 uses a small number of detection sensors to detect the medium. The size of can be detected efficiently. Therefore, the medium transport device 100 can detect the size of the medium while reducing the device size, device weight, and device cost. Furthermore, in the medium transport device 100, the detection sensors are arranged on alternately different sides with respect to the center position C in the order of distance from the center position C. This prevents the detection sensors from crowding on one side of the medium transport device 100 and causing an imbalance in the weight of the device, allowing the user to stably install the medium transport device 100.

FIG. 7(A) shows an A4 size medium M1 being conveyed at an angle.

As shown in FIG. 7A, when the medium M1 is being conveyed at an angle, the timing at which the leading edge of the medium M1 reaches the position of each detection sensor is different from each other. In the example shown in FIG. 7A, after the third detection sensor 116 disposed on one side in the width direction A2 detects the leading edge of the medium M1, the second detection sensor 115 disposed on the other side detects the leading edge of the medium M1. Detect the tip of M1. Since the detection unit 152 detects the size of the medium depending on whether each detection sensor detects the medium within a predetermined time, even if the medium M1 is conveyed at an angle, the detection unit 152 correctly detects the detection sensor through which the leading edge of the medium has passed. It is possible to correctly detect that the size of the medium M1 is A4 size.

FIG. 7B shows an A4 size medium M2 being conveyed with a slight deviation from the center position C and tilted.

In the example shown in FIG. 7B, the leading edge of the medium M2 does not pass the second detection sensor 115, but the end of the medium M2 in the width direction A2 passes the second detection sensor 115. In this case, after the fourth detection sensor 117 arranged next to the second detection sensor 115 in the width direction A2 detects the leading edge of the medium M2, the second detection sensor 115 detects the end of the medium M2 in the width direction A2. do. The detection unit 152 detects the size of the medium depending on whether each detection sensor detects the medium within a predetermined time. can correctly detect that the size is A4 size.

FIG. 8 shows an A4-sized medium M3 being conveyed with its leading edge bent.

In the example shown in FIG. 8, the corner of the leading edge of the medium M3 on the second detection sensor 115 side is bent, and after each detection sensor other than the second detection sensor 115 detects the leading edge of the medium M3, the second detection sensor 115 detects the leading edge of the medium M1. The detection unit 152 detects the size of the medium depending on whether each detection sensor detects the medium within a predetermined time. It is possible to correctly detect that the image is A4 size.

FIG. 9(A) shows a situation where an A5 size medium M4 is being conveyed without being tilted.

In the example shown in FIG. 9(A), the center position of the A5 size medium M4 is placed at the center position C of the medium transport path, and each detection sensor other than the second detection sensor 115 detects the medium M4. The second detection sensor 115 does not detect the medium M4. Therefore, the medium transport device 100 can correctly detect that the size of the medium M4 is A5 size based on the medium detection results by each detection sensor.

FIG. 9B shows an A5 size medium M5 being conveyed at an angle.

In the example shown in FIG. 9B, the center position of the A5 size medium M5 is arranged near the center position C of the medium transport path, and each detection sensor other than the second detection sensor 115 detects the medium M5. , the second detection sensor 115 does not detect the medium M5. Even if the end of the medium M5 in the width direction A2 passes the position of the second detection sensor 115, the second detection sensor 115 detects the end of the medium M5 after the fourth detection sensor 117 detects the leading edge of the medium M5. It takes a lot of time to detect. Since the detection unit 152 detects the size of the medium depending on whether each detection sensor detects the medium within a predetermined time, it can correctly detect that the size of the medium M5 is A5 size.

Note that the detection unit 152 may detect the size of the medium according to other criteria. For example, when the second detection sensor 115 or the third detection sensor 116 first detects the leading edge of the medium, the detection unit 152 determines that the size of the medium is A4 size. In this case, the detection unit 152 may determine that the size of the medium is A5 size. Generally, it is unlikely that the medium will be conveyed without being tilted at all in the width direction A2. Therefore, when a medium whose size in the width direction A2 is larger than the distance between the second detection sensor 115 and the third detection sensor 116 is conveyed, either the second detection sensor 115 or the third detection sensor 116 first detects the medium. There is a high possibility of detecting the tip of. When the second detection sensor 115 or the third detection sensor 116 first detects the leading edge of the medium, the detection unit 152 determines that the size of the medium is A4 size or A5 size, thereby appropriately determining the size of the medium. It can be estimated.

Similarly, when the fourth detection sensor 117 first detects the leading edge of the medium, the detection unit 152 determines that the size of the medium is A5 size. In this case, the detection unit 152 may determine that the size of the medium is A6 size. Furthermore, when the fifth detection sensor 118 or the first detection sensor 114 first detects the leading edge of the medium, the detection unit 152 determines that the size of the medium is A6 size or less. In this case, the detection unit 152 may determine that the size of the medium is A7 size or smaller. These allow the detection unit 152 to detect the size of the medium more quickly and easily.

Further, the detection unit 152 may detect the distance between the first detection sensor and the subsequent detection sensor arranged at both ends in the width direction A2 as the size of the medium.

In this way, the detection unit 152 detects the size of the medium based on the detection results from the plurality of detection sensors.

Next, the detection unit 152 detects the inclination of the fed medium (step S106). The detection unit 152 detects the inclination of the medium based on each detection signal obtained from each detection sensor. The detection unit 152 identifies the subsequent detection sensor located at the farthest position from the first detection sensor among the subsequent detection sensors detected in step S105. The detection unit 152 then calculates the value obtained by multiplying the elapsed time from when the first detection sensor detects the leading edge of the medium until the identified subsequent detection sensor detects the leading edge of the medium by the circumferential speed of the feeding roller 112. It is calculated as the moving distance of the medium in the medium conveyance direction A1 at the position of the continuous detection sensor. The detection unit 152 detects, as the inclination of the medium, a value obtained by dividing the calculated moving distance of the medium in the medium transport direction A1 by the distance in the width direction A2 between the first detection sensor and the specified subsequent detection sensor. .

As described above, it is generally unlikely that the medium will be conveyed without being tilted at all in the width direction A2. Therefore, as shown in FIG. 7(A), among the detection sensors through which the medium passes, the outermost detection sensor on one side in the width direction A2 (in the example shown in FIG. 7(A), the third Detection sensor 116) detects the medium first and is the first detection sensor. On the other hand, among the detection sensors through which the medium passes, the detection sensor disposed outermost on the other side in the width direction A2 (the second detection sensor 115 in the example shown in FIG. 7(A)) is the second earliest detection sensor. This is the subsequent detection sensor located at the farthest position from the The detection unit 152 determines the timing at which each detection sensor detects the medium by using the time difference between when the first detection sensor and the subsequent detection sensor located farthest from the second first detection sensor detect the medium. It is possible to detect the tilt of the medium with high accuracy by reducing the influence of errors.

Furthermore, in the example shown in FIG. 7(B), the leading edge of the medium M2 does not pass through the second detection sensor 115 disposed on the outermost side, but first passes through the fourth detection sensor 117 disposed on the inner side. The fourth detection sensor 117 becomes the first detection sensor. On the other hand, among the detection sensors through which the medium passes, the third detection sensor 116, which is disposed on the outermost side opposite to the fourth detection sensor 117 in the width direction A2, is disposed at the farthest position from the first detection sensor. It becomes the subsequent detection sensor. Since the detection unit 152 detects the inclination of the medium without using the detection result of the second detection sensor 115 through which the side portion of the medium passes, it is possible to detect the inclination of the medium with high accuracy.

Further, in the example shown in FIG. 8, when the leading edge of the medium M3 first passes the position of the fourth detection sensor 117 arranged inside the second detection sensor 115 arranged outermost, the fourth detection sensor 117 is the first detection sensor. In that case, the third detection sensor 116 arranged at the outermost side on the opposite side of the fourth detection sensor 117 in the width direction A2 becomes the subsequent detection sensor arranged at the farthest position from the first detection sensor. Since the detection unit 152 detects the inclination of the medium without using the detection result of the second detection sensor 115 through which the side portion of the medium passes, it is possible to detect the inclination of the medium with high accuracy.

On the other hand, in the example shown in FIG. 8, when the leading edge of the medium M3 first passes the position of the third detection sensor 116, the third detection sensor 116 becomes the first detection sensor. In that case, the second detection sensor 115 disposed on the outermost side opposite to the third detection sensor 116 in the width direction A2 becomes the subsequent detection sensor disposed at the farthest position from the first detection sensor. In this case, the detection accuracy of the inclination of the medium is reduced due to the bent corner of the leading edge of the medium, but since the distance in the width direction A2 between the third detection sensor 116 and the second detection sensor 115 is large, The error in the slope of is small.

Note that the detection unit 152 may detect the tilt of the medium according to other criteria. For example, the detection unit 152 extracts a pair of two detection sensors that successively detected the medium. For each extracted pair, the detection unit 152 multiplies the elapsed time from when one detection sensor detects the leading edge of the medium until the other detection sensor detects the leading edge of the medium by the peripheral speed of the feeding roller 112. The calculated value is calculated as the moving distance of the medium in the medium transport direction A1. The detection unit 152 also calculates a division value for each pair by dividing the calculated moving distance by the distance in the width direction A2 between each detection sensor. The detection unit 152 detects the median value, average value, etc. of the division values calculated for each pair as the inclination of the medium. Thereby, the detection unit 152 can detect the inclination of the medium with high accuracy by reducing the influence of the detection sensor that detects the side of the medium or the detection sensor that detects the bent corner of the medium.

In this way, the detection unit 152 detects the size of the medium based on the detection results from the plurality of detection sensors.

Next, the control unit 151 determines whether the size of the medium detected by the detection unit 152 is less than or equal to the first size threshold (step S107). The first size threshold is an example of a size threshold. The first size threshold is a size that, when a medium of that size is conveyed at an angle, is likely to come into contact with the side wall W of the conveyance path or pass through an area outside the imaging range of the imaging device 122 in the width direction A2. Set to the minimum size. The first size threshold is set, for example, to a size between the maximum size supported by the medium transport device 100 and the size of the first standard.

For example, the first size threshold is set to a size between A4 size and A5 size. As described above, if the second detection sensor 115 does not detect the medium within a predetermined time after the first detection sensor detects the medium, the detection unit 152 determines that the size of the medium is smaller than A4 size. That is, the detection unit 152 detects the medium when the second detection sensor 115 does not detect the medium within a predetermined time after the fourth detection sensor 117 disposed closer to the center than the second detection sensor 115 detects the medium. It is determined that the size is less than or equal to a first size threshold. Thereby, the detection unit 152 can easily and highly accurately determine whether the size of the medium is less than or equal to the first size threshold. Note that the first size threshold may be set to another size, such as a size between A5 size and A6 size.

If the size of the medium is larger than the first size threshold, the control unit 151 performs skew correction of the medium (step S108), and moves the process to step S112.

The control unit 151 corrects the skew of the medium by making the circumferential speeds of the plurality of feeding rollers 112 different from each other. In the width direction A2, the control unit 151 controls the peripheral speed of the feeding roller 112 arranged on the side where the medium is lagging behind to be faster than the circumferential speed of the feeding roller 112 arranged on the leading side The circumferential speed of each feed roller 112 is changed so that the The control unit 151 increases (higher) the peripheral speed of the feeding roller 112 placed on the side where the progress of the medium is delayed, and/or increases the peripheral speed of the feeding roller 112 placed on the side where the medium is ahead. Slow down (lower) the speed. For example, the control unit 151 controls the peripheral speed of the feeding roller 112 disposed on the side where the medium is lagging behind to be at least three times and ten times the circumferential speed of the feeding roller 112 disposed on the leading side. Set each peripheral speed so that it is as follows. As a result, the medium rotates around the feeding roller 112 disposed on the leading side, so that the skew of the medium is eliminated.

Furthermore, after a preset specific time has elapsed since the start of the medium skew correction, the control unit 151 returns the circumferential speed of each feeding roller 112 to the reference speed, and ends the medium skew correction. The specific time may be changed depending on the magnitude of the tilt of the medium. For example, the control unit 151 may lengthen the specific time for correcting the skew of the medium as the inclination of the medium increases.

In this way, when the size of the medium is larger than the first size threshold, the control unit 151 performs the skew correction of the medium regardless of the inclination of the medium. Generally, the medium transport device 100 is required to reduce the device size and the device cost, and the size of the medium transport path in the width direction A2 or the size of the imaging range of the imaging device 122, and the size of the medium transport device 100 The difference between the maximum size supported by the media width is small. If the medium is large and has a high possibility of coming into contact with the side wall W of the conveyance path or passing through an area outside the imaging range of the imaging device 122, the control unit 151 performs skew correction of the medium, so that the medium can be corrected more reliably. It is possible to suppress the occurrence of a jam of the medium or the occurrence of a chip of the medium in an input image.

On the other hand, if the size of the medium is less than or equal to the first size threshold, the control unit 151 determines whether the size of the medium detected by the detection unit 152 is less than or equal to the second size threshold (step S109). The second size threshold is set to a value smaller than the first size threshold. The second size threshold is determined by the size of the medium that does not come into contact with the side wall W of the conveyance path or the possibility of passing through an area within the imaging range of the imaging device 122 in the width direction A2, even if the medium of that size is conveyed at an angle. Set to a high magnitude maximum value. The first size threshold is set, for example, to a size between the first standard size and the second standard size. For example, the second size threshold is set to a size between A5 size and A6 size. The second size threshold may be set to another size, such as a size smaller than A6 size.

If the size of the medium is less than or equal to the second size threshold, the control unit 151 does not perform skew correction of the medium (step S110), and moves the process to step S112. That is, when the size of the medium is less than or equal to the second size threshold, the control unit 151 does not perform skew correction of the medium regardless of the inclination of the medium. If there is a high possibility that the medium will not come into contact with the side wall W of the transport path or pass through an area within the imaging range of the imaging device 122, the control unit 151 reduces the load on the medium by not performing skew correction of the medium. This can prevent damage to the medium and prevent damage to the medium.

On the other hand, if the size of the medium is larger than the second size threshold, the control unit 151 determines whether the tilt of the medium detected by the detection unit 152 is less than or equal to the tilt threshold (step S111).
FIG. 10 is a schematic diagram for explaining an example of the slope threshold value.

The inclination threshold value is set to such an extent that the rear end of the medium M7 of the first standard size, which is smaller than the maximum size medium M6 supported by the medium transport device 100, intersects the end of the medium M6 in the width direction A2 in the non-tilted state. The inclination θ is set when the medium M7 is inclined. That is, the inclination threshold value is determined by rotating the medium M7 around the center position of the leading edge in the width direction A2 with the center position of the medium M6 and the center position of the medium M7 being arranged at the center position C of the medium transport path. , the inclination θ is set when the rear end intersects with the end of the medium M6 in the width direction A2. Note that in consideration of the fact that the medium M5 having the size of the first standard is fed to a position shifted from the center position C, the slope threshold value may be set to a slope obtained by subtracting a margin from the above slope θ.

If the tilt of the medium is larger than the tilt threshold, the control unit 151 executes skew correction of the medium (step S108), and moves the process to step S112.

On the other hand, if the tilt of the medium is less than or equal to the tilt threshold, the control unit 151 does not perform skew correction of the medium (step S110), and moves the process to step S112.

In this way, the control unit 151 executes skew correction of the medium when the size of the medium is equal to or less than the first size threshold, when the tilt of the medium is greater than the tilt threshold, and when the tilt of the medium is equal to or less than the tilt threshold. does not perform media skew correction. That is, the control unit 151 controls the size of the medium based on the inclination of the medium when the size of the medium is such that there is a possibility that the medium will come into contact with the side wall W of the conveyance path or pass through an area outside the imaging range of the imaging device 122. Determine whether to perform skew correction. As a result, the control unit 151 can suppress the occurrence of medium jam or chipping of the medium in the input image while suppressing the occurrence of damage to the medium due to the medium skew correction.

Next, the control unit 151 obtains an input image from the imaging device 122. The control unit 151 generates a medium image by cutting out a region including the medium from the input image, and outputs the generated medium image by transmitting it to the information processing device via the interface device 132 (step S112). The control unit 151 causes the imaging device 122 to start imaging when the leading edge of the fed medium reaches the imaging position of the imaging device 122, and starts imaging when the trailing edge of the fed medium passes the imaging position. The device 122 is caused to finish imaging.

The control unit 151 periodically acquires the second medium signal from the second medium sensor 121, and changes the signal value of the second medium signal from a value indicating that the medium is not present to a value indicating that the medium is present. When this happens, it is determined that the leading edge of the medium has passed the position of the second medium sensor 121. When the leading edge of the medium passes the position of the second medium sensor 121, the control unit 151 determines that the leading edge of the medium has arrived in front of the imaging position. On the other hand, when the signal value of the second medium signal changes from a value indicating that a medium is present to a value indicating that a medium is not present, the control unit 151 controls whether the rear end of the medium It is determined that the position has been passed. The control unit 151 determines that the rear end of the medium has passed the imaging position when a second predetermined time has elapsed since the rear end of the medium passed the position of the second medium sensor 121 . The second predetermined time is set to the time required for the medium to move from the position of the second medium sensor 121 to the imaging position plus a margin. Note that the control unit 151 determines that the leading edge of the medium has reached the front of the imaging position when a predetermined first time has elapsed since the start of feeding of the medium, and a predetermined second time has elapsed. It may be determined that the rear end of the medium has passed the imaging position when the time has elapsed.

Based on the size of the medium detected by the detection unit 152, the control unit 151 identifies an area in the input image in which the medium is included. For example, the control unit 151 specifies a rectangular area of the size of the medium detected by the detection unit 152, centered on the center position in the input image, as the area containing the medium. The control unit 151 may detect the area containing the medium by detecting the rectangular area using a known image processing technique within an area obtained by enlarging the rectangular area by a predetermined margin. Thereby, the control unit 151 can cut out the area including the medium from the input image with low processing load and high precision. Furthermore, since the control unit 151 cuts out an image using the detected size of the medium to determine whether or not to perform skew correction of the medium, it is necessary to re-detect the size of the medium in order to cut out the image. As a result, the time required to cut out an image can be reduced.

Next, the control unit 151 determines whether or not a medium remains on the mounting table 103 based on the first medium signal received from the first medium sensor 111 (step S113). If the medium remains on the mounting table 103, the control unit 151 returns the process to step S104 and repeats the process from step S104 onwards.

On the other hand, if no medium remains on the mounting table 103, the control unit 151 controls the motor 131 to stop each roller (step S114), and ends the series of steps.

As described in detail above, the medium transport device 100 detects the size and inclination of the medium using a common detection sensor, and when the size of the medium is less than or equal to the first size threshold, the medium Change whether or not to perform skew correction. By using a common detection sensor for detecting the size and inclination of the medium, the medium transport device 100 can appropriately correct the skew of the medium while suppressing an increase in device weight and device cost. Ta.

FIG. 11 is a diagram showing a schematic configuration of a processing circuit 250 in a medium transport device according to still another embodiment. The processing circuit 250 is used in place of the processing circuit 150 and executes media reading processing, etc. in place of the processing circuit 150. The processing circuit 250 includes a control circuit 251, a detection circuit 252, and the like. Note that each of these units may be configured with an independent integrated circuit, microprocessor, firmware, or the like.

The control circuit 251 is an example of a control section and has the same functions as the control section 151. The control circuit 251 receives an operation signal from the operation device 105 or the interface device 132. Further, the control circuit 251 receives the first medium signal and the second medium signal from the first medium sensor 111 and the second medium sensor 121, respectively, and receives the detection results of the size and inclination of the medium from the detection circuit 252. The control circuit 251 controls the motor 131 based on the received information, acquires an input image from the imaging device 122 , generates a medium image, and outputs it to the interface device 132 .

The detection circuit 252 is an example of a detection section and has the same function as the detection section 152. The detection circuit 252 receives a first detection signal, a second detection signal, and a third detection signal from the first detection sensor 114, the second detection sensor 115, the third detection sensor 116, the fourth detection sensor 117, and the fifth detection sensor 118, respectively. , a fourth detection signal, and a fifth detection signal. The detection circuit 252 detects the size and inclination of the medium based on each received signal, and outputs the detection results to the control circuit 251.

As described in detail above, even when using the processing circuit 250, the medium transport device can now appropriately correct the skew of the medium while suppressing increases in device weight and device cost.

Although preferred embodiments have been described above, the embodiments are not limited to these. For example, the control unit 151 corrects the skew of the medium by making the peripheral speeds of the plurality of first conveyance rollers 119 and/or the plurality of first driven rollers 120 different from each other instead of the plurality of feeding rollers 112. It's okay. In that case, the plurality of first conveyance rollers 119 and/or the plurality of first driven rollers 120 are examples of the plurality of conveyance rollers. Alternatively, the control unit 151 may correct the skew of the medium by making the circumferential speeds of the plurality of second transport rollers 123 and/or the plurality of second driven rollers 124 different from each other instead of the plurality of feeding rollers 112. It's okay. In that case, the plurality of second conveyance rollers 123 and/or the plurality of second driven rollers 124 are examples of the plurality of conveyance rollers.

In these cases, the control unit 151 corrects the skew of the medium by making the circumferential speeds of each roller different, in the same way as when making the circumferential speeds of the plurality of feeding rollers 112 different. In this case as well, the control unit 151 can appropriately correct the skew of the medium and suppress the occurrence of a jam of the medium. However, by making the circumferential speeds of the plurality of feeding rollers 112 different from each other, the control unit 151 can correct the skew of the medium more quickly, and more reliably prevent the occurrence of a jam of the medium or the omission of the medium in the input image. The occurrence of can be suppressed.

Further, the control unit 151 may correct the skew of the medium by controlling a stopper (not shown). In that case, a stopper is arranged downstream of the feeding roller 112 and upstream of the first conveying roller 119 in the medium conveying direction A1. The stopper is provided so as to be movable according to the driving force from the motor 131 between a facing position where it faces the medium to be fed and a non-facing position where it does not face the medium to be fed. When a skew of the medium occurs, the control unit 151 corrects the skew of the medium by controlling the motor for driving the stopper and disposing the stopper at the opposing position for a third predetermined period of time. The medium to be fed is pushed downstream by the feeding roller 112, but the leading edge of the medium is stopped by a stopper and does not advance downstream beyond the stopper. Therefore, when the leading edge of the medium is tilted, the leading edge of the medium is rotated by the force pushed out by the feeding roller 112 so as to be substantially parallel to the width direction A2 at the stopper arrangement position.

Further, the maximum size of the medium supported by the medium transport device is not limited to A4 size, but may be A3 size or the like. In that case, the medium transport device is further provided with a detection sensor corresponding to A3 size medium. The detection sensor is located downstream of the feed roller 112 and separation roller 113 in the medium conveyance direction A1, upstream of the first conveyance roller 119 and the first driven roller 120, and spaced apart from other detection sensors in the width direction A2. It is placed side by side with other detection sensors with a space between them. The detection sensor is disposed on the opposite side of the second detection sensor 115 in the width direction A2, and is spaced apart from the center position C by a fifth distance that is greater than the first distance D1. The fifth distance is set to a distance smaller than 1/2 of the width of the A3 size medium and larger than 1/2 of the width of the A4 size medium.

In this case, in step S105, the detection unit 152 determines that the size of the medium is A3 size if the first detection sensor or the subsequent detection sensor includes a detection sensor corresponding to an A3 size medium. The detection unit 152 may determine that the size of the medium is A3 size when the detection sensor corresponding to the A3 size medium or the second detection sensor 115 first detects the leading edge of the medium. The first size threshold may be set to a size between A3 size and A4 size, and the second size threshold may be set to a size between A4 size and A5 size.

Furthermore, in the medium transport device, the detection sensors corresponding to each medium size may not be arranged only on one side of the center position C in the width direction A2, but may be arranged on both sides. In that case, a new detection sensor is arranged at a position that is line symmetrical with respect to the center position C regarding the second detection sensor 115, the third detection sensor 116, the fourth detection sensor 117, and/or the fifth detection sensor 118. Ru. In step S105, the detection unit 152 determines that the size of the medium is A4 size if at least one of the first detection sensor or the subsequent detection sensor includes a detection sensor corresponding to A4 size. The detection unit 152 detects a case where the first detection sensor or the subsequent detection sensor includes at least one of the detection sensors corresponding to a specific size, and no detection sensor corresponding to a size larger than the specific size is included. , determines that the size of the media is that particular size.

In addition, in the medium conveyance device, the second detection sensor 115, the third detection sensor 116, the fourth detection sensor 117, and/or the fifth detection sensor 118 are located at the center position C in the width direction A2 as shown in FIG. They may be placed on opposite sides of the position. Further, the medium transport device only needs to have at least two detection sensors as the plurality of detection sensors, and other detection sensors may be omitted.

Further, in the medium transport device, a detection sensor for detecting the size of the medium and a detection sensor for detecting the inclination of the medium may be provided separately. For example, on the downstream side of the first detection sensor 114, second detection sensor 115, third detection sensor 116, fourth detection sensor 117, and fifth detection sensor 118 in the medium conveyance direction A1, and each detection sensor in the width direction A2. A new detection sensor is provided at a position that overlaps with . The detection unit 152 detects the size of the medium based on each detection signal from one of the detection sensor groups, and detects the inclination of the medium based on each detection signal from the other detection sensor group. Note that each detection sensor for detecting the size of the medium and each detection sensor for detecting the inclination of the medium may be arranged at positions that do not overlap with each other in the width direction A2.

Further, the control unit 151 may accept settings of a first size threshold, a second size threshold, and/or a tilt threshold by the user. In that case, when the user inputs settings for the first size threshold, second size threshold, and/or tilt threshold using the operating device 105 or the information processing device, the control unit 151 operates the input settings. Receive from device 105 or interface device 132. As a result, the medium transport device 100 can correct the skew of the medium according to the usage or purpose of each user, such as the environment in which the medium transport device 100 is used or the type of medium fed to the medium transport device 100. It is possible to flexibly change the criteria for determining whether or not to execute. Therefore, the medium transport device 100 can improve convenience for the user.

Further, the medium conveying device may have a so-called U-turn path, and may feed and convey the medium placed on the mounting table in order from the upper side and discharge it to the discharge table. In that case, the separating roller is arranged below the feeding roller and facing the feeding roller. In this case as well, the medium transport device can appropriately correct the skew of the medium.

100 medium conveyance device, 112 feeding roller, 119 first conveyance roller, 123 second conveyance roller, 114 first detection sensor, 115 second detection sensor, 116 third detection sensor, 117 fourth detection sensor, 118 fifth detection sensor, 151 control section, 152 detection section

Claims (9)

a conveyance roller;
a plurality of detection sensors arranged at intervals in a direction perpendicular to the medium conveyance direction;
a detection unit that detects the size and inclination of the medium based on detection results by the plurality of detection sensors;
a control unit that performs skew correction of the medium;
When the size of the medium is less than or equal to a size threshold, the control unit executes skew correction of the medium when the inclination of the medium is greater than the inclination threshold, and when the inclination of the medium is less than or equal to the inclination threshold, Do not perform skew correction for
A medium conveyance device characterized by: The plurality of conveyance rollers are arranged at intervals in a direction perpendicular to the medium conveyance direction,
The medium conveyance device according to claim 1, wherein the control unit executes skew correction of the medium by mutually varying circumferential speeds of the plurality of conveyance rollers. The medium transport device according to claim 1 , wherein the control unit performs skew correction of the medium regardless of the inclination of the medium when the size of the medium is larger than the size threshold. The medium transport according to claim 1 or 2, wherein the control unit does not perform the skew correction of the medium regardless of the inclination of the medium when the size of the medium is equal to or less than a second size threshold smaller than the size threshold. Device. The plurality of detection sensors are configured such that distances from each of the plurality of detection sensors to the center position are different on one side and the other side of the center position in a direction perpendicular to the medium conveyance direction. The media transport device according to claim 1 or 2, wherein the media transport device is arranged. The plurality of detection sensors are:
a first sensor disposed on the one side and spaced apart from the central position by a first distance;
a second sensor disposed on the other side and spaced apart from the center position by a second distance smaller than the first distance;
The medium transport device according to claim 5 , further comprising: a third sensor disposed on the one side and spaced apart from the center position by a third distance that is smaller than the second distance. 6. The detection unit determines that the size of the medium is less than or equal to the size threshold when the first sensor does not detect the medium within a predetermined time after the third sensor detects the medium. The media transport device described in . The medium is transported by transport rollers,
Detecting the size and inclination of the medium based on detection results from a plurality of detection sensors arranged at intervals in a direction perpendicular to the medium conveyance direction,
performing media skew correction;
In executing the skew correction, if the size of the medium is less than or equal to a size threshold, the skew correction of the medium is performed when the inclination of the medium is greater than the inclination threshold, and when the inclination of the medium is less than or equal to the inclination threshold. does not perform media skew correction,
A medium conveyance method characterized by: A control program for a medium conveyance device including a conveyance roller and a plurality of detection sensors arranged at intervals in a direction perpendicular to a medium conveyance direction, the program comprising:
Detecting the size and inclination of the medium based on the detection results by the plurality of detection sensors,
causing the medium transport device to perform skew correction of the medium;
In executing the skew correction, if the size of the medium is less than or equal to a size threshold, the skew correction of the medium is performed when the inclination of the medium is greater than the inclination threshold, and when the inclination of the medium is less than or equal to the inclination threshold. does not perform media skew correction,
A control program characterized by:

Images