WO2023021667A1

WO2023021667A1 - Medium conveyance device

Info

Publication number: WO2023021667A1
Application number: PCT/JP2021/030460
Authority: WO
Inventors: 修一森川; 喜一郎下坂
Original assignee: 株式会社Pfu
Priority date: 2021-08-19
Filing date: 2021-08-19
Publication date: 2023-02-23
Also published as: JPWO2023021667A1

Abstract

Provided is a medium conveyance device that can satisfactorily convey a medium. This medium conveyance device comprises: a motor that generates a driving force; a first shaft that linearly extends in a direction perpendicular to the medium conveyance direction and is provided so as to rotate in accordance with the driving force; a conveyance roller that is fixed to the first shaft and conveys the medium; a second shaft; a driven roller that is rotatably provided on the second shaft and rotates in accordance with the conveyance roller; and a pressing portion that presses the central portion of the second shaft in the direction perpendicular to the medium conveyance direction to the downstream side in the medium conveyance direction.

Description

Media transport device

The present disclosure relates to media transport devices, and more particularly to media transport devices having transport rollers and driven rollers.

In general, a medium conveying device such as a scanner takes an image of a medium conveyed by a conveying roller to generate an image. In such a medium conveying device, if wrinkles occur in the conveyed medium, there is a possibility that noise is included in an image obtained by picking up the medium.

A document conveying device including two or more document conveying rollers for conveying a document and two or more driven rollers facing the document conveying roller is disclosed (see Patent Document 1). In this document conveying device, a bearing that rotatably supports the document conveying roller shaft at an axial center portion of the document conveying roller shaft that supports the document conveying roller can rotate the document conveying roller shaft at an end portion of the document conveying roller shaft. It is provided on the downstream side in the document conveying direction of the bearing that supports the support. The document conveying roller shaft is composed of a single document conveying roller shaft, and is rotatably supported by a third bearing while being curved toward the downstream side in the document conveying direction.

A medium conveying device has been disclosed that includes a rotationally driven driving roller that conveys a medium and a driven roller that nips the medium between the driving roller and is driven to rotate (see Patent Document 2). This medium conveying device includes a pressing member disposed on one shaft end side and the other shaft end side of a rotating shaft of a driven roller and pressing the rotating shaft in a direction in which the driven roller contacts the driving roller; the rotating shaft and the pressing member; and a spacer interposed between them.

Patent No. 4024486 JP 2019-64762 A

A medium conveying device is required to convey the medium satisfactorily.

The purpose of the medium transport device is to enable the medium to be transported satisfactorily.

A medium transporting device according to one aspect of an embodiment includes a motor that generates a driving force, and a first shaft that extends linearly in a direction orthogonal to a medium transporting direction and is provided so as to rotate according to the driving force. a conveying roller fixed to a first shaft for conveying a medium; a second shaft; a driven roller rotatably provided on the second shaft and rotating following the conveying roller; and a medium conveying direction of the second shaft. and a pressing portion that presses the center portion in the direction perpendicular to the direction to the downstream side in the medium conveying direction.

In addition, the medium conveying device according to one aspect of the embodiment includes a motor that generates a driving force, and a first motor that extends linearly in a direction orthogonal to the medium conveying direction and is provided to rotate according to the driving force. a shaft, a transport roller that is fixed to the first shaft and transports the medium, a second shaft that is inclined such that a central portion in a direction orthogonal to the medium transport direction is located downstream of the end portions in the medium transport direction; a driven roller that is rotatably provided on the second shaft and that rotates following the conveying roller.

According to this embodiment, the medium conveying device can convey the medium satisfactorily.

The objects and advantages of the present invention may be realized and obtained by using the components and combinations particularly pointed out in the claims. Both the foregoing general description and the following detailed description are exemplary and explanatory, and are not limiting of the invention as claimed.

1 is a perspective view showing a medium conveying device 100 according to an embodiment; FIG. 4 is a diagram for explaining a transport path inside the medium transport device 100; FIG. 3 is a schematic diagram for explaining a transport mechanism 130; FIG. FIG. 3 is a schematic diagram for explaining a first driven roller 117 and the like; FIG. 3 is a schematic diagram for explaining a first driven roller 117 and the like; 4 is a schematic diagram for explaining a first pressing member 133; FIG. (A) and (B) are schematic diagrams for explaining the first pressing member 133. FIG. 4A and 4B are schematic diagrams for explaining the operation of the transport mechanism 130. FIG. 4A and 4B are schematic diagrams for explaining the operation of the transport mechanism 130. FIG. 1 is a block diagram showing a schematic configuration of a medium conveying device 100; FIG. 2 is a diagram showing a schematic configuration of a storage device 150 and a processing circuit 160; FIG. 7 is a flow chart showing an example of the operation of medium reading processing; (A) and (B) are schematic diagrams for explaining another first pressing member 233. FIG. 10 is a flow chart showing an example of the operation of another medium reading process; (A) and (B) are schematic diagrams for explaining another first pressing member 333. FIG. (A) and (B) are schematic diagrams for explaining another first pressing member 333. FIG. FIG. 11 is a schematic diagram for explaining another support member 437; FIG. 11 is a schematic diagram for explaining another transport mechanism 530; FIG. 11 is a schematic diagram for explaining another transport mechanism 530; 6 is a schematic diagram for explaining another transport mechanism 630. FIG. 7 is a schematic diagram for explaining another transport mechanism 730. FIG. 7 is a schematic diagram for explaining another transport mechanism 730. FIG. 8 is a diagram showing a schematic configuration of another processing circuit 860; FIG.

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

FIG. 1 is a perspective view showing a medium conveying device 100 configured as an image scanner. The medium conveying device 100 conveys a medium, which is an original, and captures an image. The medium may be paper, thin paper, cardboard, card, envelope, or the like. The media transport device 100 may be a facsimile machine, a copier, 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 operation 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 orthogonal to the medium transport direction, and arrow A3 indicates the height direction orthogonal to the medium transport surface. Hereinafter, upstream refers to upstream in the medium transport direction A1, and downstream refers to downstream in the medium transport direction A1.

The upper housing 102 is arranged to cover the upper surface of the medium transporting device 100, and is rotatable to the lower housing 101 by a hinge H so that it can be opened and closed when the medium is clogged or when cleaning the inside of the medium transporting device 100. are engaged in

The mounting table 103 engages with the lower housing 101 and mounts a medium to be fed and transported. The ejection table 104 engages with the upper housing 102 and places the ejected medium. Note that the discharge table 104 may be engaged with the lower housing 101 .

The operation device 105 has an input device such as a button and an interface circuit that acquires signals from the input device, receives an input operation by the user, and outputs an operation signal according to the user's input operation. The display device 106 has a display including liquid crystal, organic EL (Electro-Luminescence), etc. and an interface circuit for outputting 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. FIG.

The transport path inside the medium transport device 100 includes a first medium sensor 111, a feed roller 112, a separation roller 113, an ultrasonic sensor 114, a second medium sensor 115, a first transport roller 116, a first driven roller 117, and an imaging device. 118, a second conveying roller 119, a second driven roller 120, and the like.

The number of each of the feeding roller 112, the separation roller 113, the first conveying roller 116, the first driven roller 117, the second conveying roller 119 and/or the second driven roller 120 is not limited to one, and may be plural. good. In that case, the plurality of feeding rollers 112, separation rollers 113, first conveying rollers 116, first driven rollers 117, second conveying rollers 119 and/or second driven rollers 120 are spaced apart in the width direction A2. placed side by side.

The upper surface of the lower housing 101 forms the lower guide 101a of the medium transport path, and the lower surface of the upper housing 102 forms the upper guide 102a of the medium transport path. The lower guide 101a forms a media transport surface.

The first medium sensor 111 is arranged upstream from 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 mounted on the mounting table 103 . The first medium sensor 111 generates and outputs a first medium signal whose signal value changes depending on whether or not the medium is mounted on the mounting table 103 . Note that the first medium sensor 111 is not limited to a contact detection sensor, and any other sensor capable of detecting the presence or absence of a medium, such as a light detection sensor, may be used as the first medium sensor 111 .

The feeding roller 112 is provided in the lower housing 101, and separates and feeds the medium placed on the placing table 103 in order from the bottom. The separation roller 113 is a so-called brake roller or retard roller, is provided in the upper housing 102, is arranged to face the feeding roller 112, and rotates in the direction opposite to the medium feeding direction. Note that the feeding roller 112 is provided in the upper housing 102 and the separation roller 113 is provided in the lower housing 101, and the feeding roller 112 feeds the medium placed on the mounting table 103 in order from the top. good.

The ultrasonic sensor 114 is arranged downstream from the feed roller 112 and the separation roller 113 and upstream from the first conveying roller 116 and the first driven roller 117 . The ultrasonic sensor 114 includes an ultrasonic transmitter 114a and an ultrasonic receiver 114b. The ultrasonic transmitter 114a and the ultrasonic receiver 114b are arranged in the upper housing 102 and the lower housing 101, respectively, in the vicinity of the medium transport path so as to face each other across the transport path. The ultrasonic transmitter 114a transmits ultrasonic waves. On the other hand, the ultrasonic receiver 114b receives the ultrasonic waves emitted by the ultrasonic transmitter 114a and passing through a medium, and generates and outputs ultrasonic signals, which are electrical signals corresponding to the received ultrasonic waves. The ultrasonic transmitter 114 a may be arranged in the lower housing 101 and the ultrasonic receiver 114 b may be arranged in the upper housing 102 .

The second medium sensor 115 is arranged downstream from the feed roller 112 and the separation roller 113 and upstream from the first conveying roller 116 and the first driven roller 117, and detects the medium conveyed to that position. The second medium sensor 115 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 (Light Emitting Diode) or the like, and emits light toward the medium transport path. On the other hand, the light receiver receives the light emitted by the light emitter and guided by the light guide tube. When a medium exists at a position facing the second medium sensor 115, 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. The light receiver generates and outputs a second medium signal whose signal value changes depending on whether or not the medium is present at the position of the second medium sensor 115 based on the intensity of the received light.

A reflecting member such as a mirror may be used instead of the light guide tube. Also, the light emitter and the light receiver may be provided facing each other across the medium transport path. Further, the second medium sensor 115 may detect the presence of the medium by a contact detection sensor or the like that causes a predetermined current to flow when the medium is in contact or when the medium is not in contact.

The first conveying roller 116 and the first driven roller 117 are examples of a conveying roller and a driven roller, respectively, and are arranged on the downstream side of the feeding roller 112 so as to face each other. The first conveying roller 116 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 118 . The first driven roller 117 is provided below the first conveying roller 116 in the lower housing 101 and rotates following the first conveying roller 116 .

The imaging device 118 is arranged downstream of the first transport roller 116 and captures an image of the medium transported by the first transport roller 116 . The image pickup device 118 includes a first image pickup device 118a and a second image pickup device 118b arranged to face each other across the medium transport path. The first imaging device 118a has a linear optical system type CIS (Contact Image Sensor) line sensor having CMOS (Complementary Metal Oxide Semiconductor) imaging elements linearly arranged in the main scanning direction. Also, the first imaging device 118a has a lens that forms an image on the imaging device, and an A/D converter that amplifies an electrical signal output from the imaging device and performs analog/digital (A/D) conversion. The first imaging device 118a captures an image of the surface of the medium being conveyed, generates an input image, and outputs the input image, under the control of a processing circuit, which will be described later.

Similarly, the second imaging device 118b has a linear optical system type CIS line sensor having CMOS imaging elements linearly arranged in the main scanning direction. Also, the second imaging device 118b has a lens that forms an image on the imaging device, and an A/D converter that amplifies an electrical signal output from the imaging device and performs analog/digital (A/D) conversion. The second image capturing device 118b captures an image of the back surface of the medium being conveyed, generates an input image, and outputs the input image, under the control of a processing circuit, which will be described later.

It should be noted that the medium conveying device 100 may have only one of the first imaging device 118a and the second imaging device 118b and read only one side of the medium. Also, instead of the line sensor of the same magnification optical system type CIS provided with the CMOS imaging device, a line sensor of the same magnification optical system type CIS provided with the CCD (Charge Coupled Device) imaging device may be used. Also, a reduction optics type line sensor having a CMOS or CCD imaging device may be used.

The second conveying roller 119 and the second driven roller 120 are arranged on the downstream side of the imaging device 118 so as to face each other. The second conveying roller 119 is provided on the upper housing 102 , conveys the medium by the first conveying roller 116 and the first driven roller 117 , and discharges the medium imaged by the imaging device 118 onto the discharge table 104 . The second driven roller 120 is provided below the second conveying roller 119 in the lower housing 101 and rotates following the second conveying roller 119 .

The medium placed on the mounting table 103 moves between the lower guide 101a and the upper guide 102a in the medium conveying direction A1 by rotating the feeding roller 112 in the direction of the arrow A4 in FIG. 2, that is, in the medium feeding direction. transported towards. The separation roller 113 rotates in the direction of the arrow A5, that is, in the opposite direction to the medium feeding direction, when feeding the medium. When a plurality of media are placed on the mounting table 103 due to the action of the feeding roller 112 and the separation roller 113, only the medium that is in contact with the feeding roller 112 among the media placed on the mounting table 103 are separated. This restricts the conveyance of media other than the separated media (prevention of double feeding).

The medium is fed between the first conveying roller 116 and the first driven roller 117 while being guided by the lower guide 101a and the upper guide 102a. The medium is fed between the first imaging device 118a and the second imaging device 118b by rotating the first transport roller 116 in the direction of arrow A6. The medium read by the imaging device 118 is ejected onto the ejection table 104 as the second transport roller 119 rotates in the direction of arrow A7.

FIG. 3 is a perspective view for explaining the transport mechanism 130 of the medium transport device 100. FIG.

As shown in FIG. 3, the transport mechanism 130 includes a first transport roller 116, a first driven roller 117, a second transport roller 119, and a second driven roller 120, as well as a first shaft 131, a second shaft 132, a second It has a first pressing member 133, a third shaft 134, a fourth shaft 135, a second pressing member 136, and the like. In the example shown in FIG. 3, two each of the first conveying rollers 116, the first driven rollers 117, the second conveying rollers 119, and the second driven rollers 120 are arranged.

The first shaft 131 extends linearly in a width direction A2 orthogonal to the medium transport direction, and is provided so as to rotate according to a driving force generated by a motor, which will be described later. A first conveying roller 116 is fixed to the first shaft 131 so as to rotate as the first shaft 131 rotates.

The second shaft 132 faces the first shaft 131 and extends substantially parallel to the width direction A2 orthogonal to the medium conveying direction. A first driven roller 117 is provided on the second shaft 132 so as to be rotatable along a direction perpendicular to the extending direction of the second shaft 132 .

The first pressing member 133 is an example of a pressing portion, and is arranged to abut on the second shaft 132 between the two first driven rollers 117, that is, at the central portion in the width direction A2 orthogonal to the medium conveying direction. be done. In particular, the first pressing member 133 is preferably arranged at the central position of the arrangement positions of the first driven rollers 117 in the width direction A2. As a result, the two first driven rollers 117 are arranged line-symmetrically with respect to the first pressing member 133, and the pressing force with which each first driven roller 117 presses each first conveying roller 116 becomes uniform. The medium transport device 100 can suppress the occurrence of skew in the medium. The first pressing member 133 is provided so as to contact the lower side of the second shaft 132 so as to press the second shaft 132 toward the first shaft 131 side, that is, upward.

The third shaft 134 extends linearly in the width direction A2 orthogonal to the medium conveying direction, and is provided so as to rotate according to a driving force generated by a motor, which will be described later. A second conveying roller 119 is fixed to the third shaft 134 so as to rotate as the third shaft 134 rotates.

The fourth shaft 135 faces the third shaft 134 and is provided so as to extend linearly and straightly in the width direction A2 orthogonal to the medium conveying direction. A second driven roller 120 is provided on the fourth shaft 135 so as to be rotatable along a direction perpendicular to the extending direction of the fourth shaft 135 .

The second pressing member 136 is an example of a second pressing portion, and is arranged to contact the fourth shaft 135 between the two second driven rollers 120, that is, at the center in the width direction A2 orthogonal to the medium conveying direction. placed in In particular, the second pressing member 136 is preferably arranged at the central position of the arrangement positions of the second driven rollers 120 in the width direction A2. As a result, the two second driven rollers 120 are arranged line-symmetrically with respect to the second pressing member 136, and the pressing force with which each of the second driven rollers 120 presses each of the second conveying rollers 119 becomes uniform. The medium transport device 100 can suppress the occurrence of skew in the medium. The second pressing member 136 is provided so as to contact the lower side of the fourth shaft 135 so as to press the fourth shaft 135 toward the third shaft 134 side, that is, upward.

4 and 5 are schematic diagrams for explaining the first driven roller 117 and the second shaft 132. FIG. 4 is a perspective view of the first driven roller 117 and the second shaft 132, and FIG. 5 is a schematic side view of the first driven roller 117 and the second shaft 132. FIG.

As shown in FIGS. 4 and 5, the medium transport device 100 further has a support member 137. As shown in FIG. The support member 137 is formed of a resin member or a metal member, and is provided so as to support the second shaft 132 outside the two first driven rollers 117, that is, at the end portion in the width direction A2 orthogonal to the medium conveying direction. be done. The support member 137 is formed with a notch (or opening) into which the end of the second shaft 132 in the width direction A2 is inserted. A planar support surface 137a is provided in the notch (or opening). On the other hand, the end of the second shaft 132 in the width direction A2 is provided with a D-cut supported surface 132a. The second shaft 132 is fixed by the support member 137 and is non-rotatably provided by the contact between the support surface 137a and the supported surface 132a. On the other hand, the first driven roller 117 is rotatably provided with respect to the second shaft 132 .

Since the first driven roller 117 is rotatably provided with respect to the second shaft 132, even when the center portion of the second shaft 132 in the width direction A2 is pressed downstream as will be described later, the second driven roller 120 rotates well following the first transport roller 116 .

6 and 7 (A) and (B) are schematic diagrams for explaining the first pressing member 133. FIG. 6 is a perspective view of the first pressing member 133 with the second shaft 132 mounted thereon, and FIG. 7A shows the first pressing member 133 without the second shaft 132 mounted thereon. 7B is a schematic view of the first pressing member 133 as viewed from the side.

As shown in FIGS. 6 and 7(A) and (B), the first pressing member 133 has a first contact surface 133a. The first contact surface 133 a contacts the second shaft 132 and presses the second shaft 132 . The first contact surface 133a is an example of an inclined surface, and is inclined with respect to the medium conveying surface parallel to the medium conveying direction A1 and the width direction A2, particularly downward toward the downstream side. formed in That is, when the first pressing member 133 presses the second shaft 132 from below along the height direction A3 perpendicular to the medium conveying surface, the first pressing member 133 is positioned at the center of the second shaft 132 in the width direction A2 perpendicular to the medium conveying direction. is provided so as to press the portion toward the downstream side in the medium conveying direction A1.

FIG. 8 is a schematic diagram for explaining the operation of the transport mechanism 130. FIG. FIG. 8 is a schematic diagram of the transport mechanism 130 viewed from the side.

As described above, the second shaft 132 is provided to face the first shaft 131 and the fourth shaft 135 is provided to face the third shaft 134 . However, as shown in FIG. 8, the second shaft 132 is arranged upstream of the first shaft 131 . As a result, the first driven roller 117 provided below the first conveying roller 116 is arranged upstream of the first conveying roller 116 . Therefore, the nip surface between the first conveying roller 116 and the first driven roller 117 is inclined downward toward the downstream side. On the other hand, the fourth shaft 135 is arranged downstream of the third shaft 134 . As a result, the second driven roller 120 provided below the second conveying roller 119 is arranged downstream of the second conveying roller 119 . Therefore, the nip surface between the second conveying roller 119 and the second driven roller 120 is inclined upward toward the downstream side.

In FIG. 8, a route R indicates a route ideally passed by the leading edge of the medium to be conveyed. Since the nip surface between the first conveying roller 116 and the first driven roller 117 is inclined downward toward the downstream side, the leading edge of the medium conveyed by the first conveying roller 116 and the first driven roller 117 is Conveyed downward. The leading edge of the medium contacts the glass surface G of the first imaging device 118a and is conveyed along the glass surface G. Since the nip surface between the second conveying roller 119 and the second driven roller 120 is inclined upward toward the downstream side, the leading edge of the medium passing between the first imaging device 118a and the second imaging device 118b is , is pulled by the second transport roller 119 and the second driven roller 120 .

By conveying the leading edge of the medium along the glass surface G, the distance from the medium to each imaging sensor of the imaging device 118 is constant at the imaging position. Therefore, even when a 1:1 optical system type CIS with a shallow depth of field is used, the occurrence of defocus is suppressed, and the imaging device 118 can obtain a stable image. In particular, since the distance from the medium to each imaging sensor of the imaging device 118 is constant in the width direction A2 (main scanning direction), occurrence of horizontal unevenness in the input image is suppressed.

In addition, since the leading edge of the medium is conveyed along the glass surface G, the cleaning of the glass surface G, that is, the removal of foreign matter on the glass surface G can be performed by the leading edge of the medium. Foreign matter may adhere not only to the glass surface G of the first imaging device 118a but also to the glass surface of the second imaging device 118b. , and is likely to adhere to the glass surface G of the first imaging device 118a. By conveying the leading edge of the medium along the glass surface G of the first imaging device 118a arranged below, the medium conveying device 100 can also remove foreign matter that has fallen from the glass surface of the second imaging device 118b. It becomes possible.

Further, as shown in FIG. 8, the first pressing member 133 has a first elastic member 133b. The first elastic member 133 b is a spring member such as a torsion recoil spring, and is provided so that one end is supported by the lower housing 101 and the other end is in contact with the first pressing member 133 . Note that the first elastic member 133b may be another spring member such as a plate spring, or a rubber member or the like. The first elastic member 133b applies an upward pressing force along the height direction A3 to the first contact surface 133a.

On the other hand, the second pressing member 136 has a second contact surface 136a. The second contact surface 136 a contacts the fourth shaft 135 and presses the fourth shaft 135 . The second contact surface 136a is formed parallel to the medium transport surface. Also, the second pressing member 136 has a second elastic member 136b. The second elastic member 136 b is a spring member such as a torsion recoil spring, and is provided so that one end is supported by the lower housing 101 and the other end is in contact with the second pressing member 136 . Note that the second elastic member 136b may be another spring member such as a leaf spring, or a rubber member or the like. The second elastic member 136b applies an upward pressing force along the height direction A3 to the second contact surface 136a.

FIG. 9 is a schematic diagram for explaining the operation of the transport mechanism 130. FIG. FIG. 9 is a schematic diagram of the transport mechanism 130 viewed from above.

As described above, the first contact surface 133a of the first pressing member 133 is inclined downward toward the downstream side, and the central portion of the second shaft 132 in the width direction A2 is moved by the first elastic member 133b. Press upwards. As a result, the first pressing member 133 presses the central portion of the second shaft 132 in the width direction A2 orthogonal to the medium transport direction toward the first shaft 131 side, and also presses it toward the downstream side in the medium transport direction A1. Therefore, as shown in FIG. 9, the second shaft 132 is curved such that the central portion in the width direction A2 is arranged on the downstream side and the end portions in the width direction A2 are arranged on the upstream side. As a result, each of the first driven rollers 117 having the second shaft 132 as a rotation axis rotates so as to convey the medium outward in the width direction A2, and the medium is conveyed so as to be pulled outward. .

Therefore, the medium conveying device 100 can suppress the occurrence of wrinkles in the medium. When wrinkles occur in the medium being transported, there is a possibility that gradation will deteriorate and noise will occur in an image of the medium, particularly a color image or a grayscale image. By suppressing the occurrence of wrinkles in the medium, the medium transport device 100 can suppress the deterioration of the gradation and the occurrence of noise in the input image due to the wrinkles of the medium.

In particular, the first driven roller 117 provided below the first conveying roller 116 is arranged upstream of the first conveying roller 116, and the first contact surface 133a of the first pressing member 133 The central portion of the shaft 132 in the width direction A2 is pressed upward. Therefore, if the first pressing member 133 does not press the central portion of the second shaft 132 in the width direction A2 toward the downstream side, the second shaft 132 is arranged to release the pressing force of the first elastic member 133b. It curves so that the central portion in the width direction A2 is arranged on the upstream side. As a result, each of the first driven rollers 117 having the second shaft 132 as a rotation axis rotates to convey the medium inward in the width direction A2, and the medium is conveyed so as to be pressed inward. . Therefore, wrinkles are likely to occur in the medium. In the medium conveying device 100, the first pressing member 133 presses the central portion of the second shaft 132 in the width direction A2 to the downstream side, so that it is possible to satisfactorily suppress the occurrence of wrinkles in the medium.

On the other hand, the second driven roller 120 provided below the second conveying roller 119 is arranged downstream of the second conveying roller 119, and the second contact surface 136a of the second pressing member 136 is the fourth contact surface. The central portion of the shaft 135 in the width direction A2 is pressed upward. Therefore, the fourth shaft 135 is curved such that the central portion in the width direction A2 is arranged downstream so as to release the pressing force of the second elastic member 136b. As a result, each of the second driven rollers 120 having the rotation axis of the fourth shaft 135 rotates to convey the medium outward in the width direction A2, and the medium is conveyed so as to be pulled outward. . Therefore, the occurrence of wrinkles in the medium is suppressed.

As described above, the second contact surface 136a of the second pressing member 136 is formed parallel to the medium transport surface. Therefore, the second pressing member 136 moves the central portion of the fourth shaft 135 in the width direction A2 orthogonal to the medium transport direction upward (toward the third shaft 134 side) along the height direction A3 orthogonal to the medium transport surface. ) to press. As a result, the second pressing member 136 can prevent the fourth shaft 135 from bending too much, and can prevent damage to the medium due to excessive outward force being applied to the medium.

On the other hand, in the medium conveying device 100, the first shaft 131, which is the rotating shaft of the first conveying roller 116, and the third shaft 134, which is the rotating shaft of the second conveying roller 119, are provided so as to extend straight. As a result, the medium conveying device 100 can secure the medium conveying force of the first conveying roller 116 and the second conveying roller 119 and appropriately convey the medium.

The second pressing member 136, like the first pressing member 133, presses the central portion of the fourth shaft 135 in the width direction A2 to the downstream side, and pushes the fourth shaft 135 so that the central portion thereof in the width direction A2 is downstream. It may be curved so that it is positioned at

Also, the first contact surface 133a of the first pressing member 133 may be formed parallel to the medium transport surface instead of being formed to be inclined with respect to the medium transport surface. In that case, the first elastic member 133b of the first pressing member 133 is inclined with respect to the height direction A3 so that the first pressing member 133 presses the second shaft 132 downstream in the medium transport direction A1. is provided so as to apply force to the first pressing member 133 toward .

FIG. 10 is a block diagram showing a schematic configuration of the medium conveying device 100. As shown in FIG.

The medium transport device 100 further includes a motor 141, an interface device 142, a storage device 150, a processing circuit 160, etc., in addition to the configuration described above.

The motor 141 has one or more motors, and is used to rotate the rotating shaft of the feeding roller 112, the rotating shaft of the separating roller 113, the first shaft 131, and the third shaft 134 according to control signals from the processing circuit 160. to generate the driving force of Accordingly, the motor 141 rotates the feeding roller 112, the separating roller 113, the first conveying roller 116, and the second conveying roller 119 to convey the medium.

The interface device 142 has an interface circuit conforming to a serial bus such as USB, for example, and is electrically connected to an information processing device (for example, personal computer, personal digital assistant, etc.) (not shown) to receive an input image and various information. Send and receive. Also, instead of the interface device 142, 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 have 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 150 includes memory devices such as RAM (Random Access Memory) and ROM (Read Only Memory), fixed disk devices such as hard disks, or portable storage devices such as flexible disks and optical disks. The storage device 150 also stores computer programs, databases, tables, and the like used for various processes of the medium transport device 100 . The computer program may be installed in the storage device 150 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 160 operates based on a program stored in the storage device 150 in advance. The processing circuit is, for example, a CPU (Central Processing Unit). As the processing circuit 160, a DSP (digital signal processor), LSI (large scale integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), or the like may be used.

The processing circuit 160 is connected to the operation device 105, the display device 106, the first medium sensor 111, the ultrasonic sensor 114, the second medium sensor 115, the imaging device 118, the motor 141, the interface device 142, the storage device 150, and the like. control each part of The processing circuit 160 performs driving control of the motor 141, imaging control of the imaging device 118, and the like based on the first medium signal and the second medium signal received from the first medium sensor 111 and the second medium sensor 115, respectively. The processing circuit 160 acquires an input image from the imaging device 118 and transmits it to the information processing device via the interface device 142 .

FIG. 11 is a diagram showing a schematic configuration of the storage device 150 and the processing circuit 160. As shown in FIG.

As shown in FIG. 11, the storage device 150 stores a control program 151, a detection program 152, a press control program 153, and the like. Each of these programs is a functional module implemented by software running on a processor. The processing circuit 160 reads each program stored in the storage device 150 and operates according to each read program. Thereby, the processing circuit 160 functions as a control section 161 , a detection section 162 and a pressing control section 163 .

FIG. 12 is a flow chart showing an example of the operation of the medium reading process of the medium conveying device 100. FIG.

An example of the operation of the medium reading process of the medium conveying device 100 will be described below with reference to the flowchart shown in FIG. The operation flow described below is executed mainly by the processing circuit 160 in cooperation with each element of the medium transport device 100 based on a program stored in the storage device 150 in advance.

First, the control unit 161 receives an instruction to read a medium from the operation device 105 or the interface device 142 when a user inputs an instruction to read the medium using the operation device 105 or the information processing device. (step S101).

Next, the control unit 161 acquires the first medium signal from the first medium sensor 111, and determines whether or not the medium is placed on the placing table 103 based on the acquired first medium signal (step S102). If no medium is placed on the placing table 103, the control unit 161 terminates the series of steps.

On the other hand, when a medium is placed on the placing table 103, the control unit 161 drives the motor 141 to rotate the feeding roller 112, the separating roller 113, the first conveying roller 116, and the second conveying roller 119. to convey the medium (step S103).

Next, the control unit 161 waits until the leading edge of the medium passes the position of the second medium sensor 115 (step S104). The control unit 161 periodically acquires the second medium signal from the second medium sensor 115, and the signal value of the second medium signal changes from a value indicating the absence of the medium to a value indicating the presence of the medium. Then, it is determined that the leading edge of the medium has passed the position of the second medium sensor 115 .

Next, the control unit 161 causes the imaging device 118 to image a medium, acquires an input image from the imaging device 118, and outputs the acquired input image by transmitting it to the information processing device via the interface device 142. (Step S105).

Next, based on the first medium signal received from the first medium sensor 111, the control unit 161 determines whether or not the medium remains on the mounting table 103 (step S106). When the medium remains on the mounting table 103, the control unit 161 returns the process to step S104 and repeats the processes of steps S104 to S106.

On the other hand, when no medium remains on the mounting table 103, the control unit 161 controls the motor 141 to stop the feeding roller 112, the separating roller 113, the first conveying roller 116, and the second conveying roller 119 ( Step S107), the series of steps ends.

As described in detail above, the medium transporting device 100 straightens the first shaft 131, which is the rotating shaft of the first transport roller 116, and bends only the second shaft 132, which is the rotating shaft of the first driven roller 117. Thus, it is possible to suppress the occurrence of wrinkles in the medium while ensuring the medium conveying force. Therefore, the medium conveying device 100 can convey the medium satisfactorily.

In particular, the medium conveying device 100 suppresses wrinkling of the medium between the feed roller 112 and separation roller 113 (separation section) and the first conveyance roller 116 and first driven roller 117 (conveyance section). became possible.

In addition, the medium conveying device 100 presses the central portion of the second shaft 132 in the width direction A2 using only one first pressing member 133 having an inclined first contact surface 133a. The roller 117 is rotated outward in the width direction A2. As a result, the medium transport device 100 can suppress the occurrence of wrinkles in the medium while suppressing an increase in device cost.

Also, in the medium conveying device 100, the first shaft 131, which is the rotating shaft (driving shaft) of the first conveying roller 116, is provided so as to straightly extend without being curved. As a result, the medium transport device 100 can suppress the occurrence of metal fatigue of the first shaft 131 and wear between the first shaft 131 and the bearing of the first shaft 131, thereby suppressing a reduction in device life. It has become possible.

In general, in order to maintain the stability of the medium conveying force, it is necessary to increase the diameter of the rotating shaft of the transport roller (thicken the rotating shaft) to reduce the deflection due to the pressing force from the driven roller. If the rotating shaft of the conveying roller is curved while increasing the diameter of the rotating shaft of the conveying roller, the reaction force applied to the rotating shaft of the conveying roller increases and the stability of the medium conveying force is impaired. In particular, when the medium transport device supports transport of a large medium such as A3 paper, the shaft, which is the rotation axis of each transport roller, becomes longer, and the reaction force applied to the shaft increases. On the other hand, if the shaft diameter of the rotating shaft of the transport roller is made smaller (the rotating shaft is made thinner), the transport roller vibrates more during transport of the medium, and the stability of the medium transport force is impaired. On the other hand, in the medium conveying device 100, the first shaft 131, which is the rotating shaft of the first conveying roller 116, extends linearly. However, the stability of the medium conveying force is not impaired.

FIGS. 13A and 13B are schematic diagrams for explaining the first pressing member 233 in a medium conveying device according to another embodiment. 13A and 13B are schematic diagrams of the first pressing member 233 viewed from the side. FIG. 13A shows the first pressing member 233 placed at the first position, and FIG. 13B shows the first pressing member 233 placed at a second position different from the first position.

As shown in FIGS. 13A and 13B, the medium transporting device according to the present embodiment has a first pressing member 233 instead of the first pressing member 133, and further includes a second motor 238 and an angle changing member. 239.

The first pressing member 233 has a first contact surface 233a, a first elastic member 233b, a rotating shaft 233c and an engaging portion 233d. The first contact surface 233a contacts and presses the second shaft 132 in the same manner as the first contact surface 133a. The first contact surface 233a is an example of an inclined surface, and is formed so as to incline with respect to the medium transport surface, particularly so as to incline downward toward the downstream side. The first elastic member 233b has the same configuration as the first elastic member 133b, and applies an upward pressing force along the height direction A3 to the first contact surface 233a. The rotary shaft 233c is fixed to the lower housing 101 and supports the first pressing member 233 so as to be rotatable (swingable). That is, the first pressing member 233, particularly the first contact surface 233a, is provided so as to be rotatable (swingable) around the rotary shaft 233c. The engaging portion 233 d is provided so as to engage with the angle changing member 239 .

The second motor 238 generates a second driving force for sliding the angle changing member 239 .

The angle changing member 239 is an example of an angle changing portion. The angle changing member 239 slides in the direction of arrow A8 by the second driving force generated by the second motor 238, and changes the inclination angle of the first contact surface 233a of the first pressing member 233 with respect to the medium conveying surface. provided in The angle changing member 239 has an engaged portion 239a. The engaged portion 239a supports the engaging portion 233d of the first pressing member 233 so as to sandwich it.

When the device is started, the angle changing member 239 is arranged at the initial position shown in FIG. 13(A), and the first pressing member 233 is arranged at the first position. On the other hand, when the second motor 238 rotates to generate the second driving force, the angle changing member 239 moves to the movement position shown in FIG. 13B, and the first pressing member 233 is placed at the second position. be done. The engaging portion 233d of the first pressing member 233 moves upward and to the left while being sandwiched by the engaged portion 239a of the angle changing member 239, and the first pressing member 233 rotates (swings) around the rotation shaft 233c. do. As a result, the inclination angle of the first contact surface 233a with respect to the medium transport surface is changed, and the force with which the first pressing member 233 presses the central portion of the second shaft 132 in the width direction A2 to the downstream side increases.

The angle changing member 239 is slid manually by the operator instead of by the second driving force from the second motor 238, and the inclination angle of the first contact surface 233a of the first pressing member 233 with respect to the medium conveying surface is changed to may be provided to change. As described above, the first driven rollers 117 are provided in the lower housing 101, and the first transport rollers 116 are provided in the upper housing provided to be openable (rotatable) by the hinge H with respect to the lower housing 101. It is provided on body 102 . The hinge H, which is the rotation support portion of the upper housing 102, has a certain amount of backlash, and the arrangement position (rotational position) of the hinge H varies from device to device. Therefore, the contact state between the first conveying roller 116 and the first driven roller 117 varies from apparatus to apparatus. Therefore, the balance between the force component of the first driven roller 117 that presses the first transport roller 116 in the medium transport direction A1 and the force component that presses the first transport roller 116 in the height direction A3 varies from device to device. The outward force in the width direction A2 applied to the conveyed medium varies from device to device. In the medium conveying device, the angle changing member 239 is provided so that the inclination angle of the first contact surface 233a can be changed. You can adjust the size.

In addition, since the angle changing member 239 changes the direction of the force while maintaining the overall magnitude of the force that the first driven roller 117 pushes the first conveying roller 116 constant, the medium conveying force is kept constant during medium conveying. can keep. Therefore, the medium conveying device can suppress the occurrence of stretching or contraction of the medium in the sub-scanning direction within the input image.

FIG. 14 is a flow chart showing an example of the operation of the medium reading process of the medium conveying device according to this embodiment.

The flowchart shown in FIG. 14 is executed instead of the flowchart shown in FIG. The processing of steps S201 to S204 and S207 to S209 in FIG. 14 is the same as the processing of steps S101 to S104 and S105 to S107 in FIG. . Note that the angle changing member 239 is arranged at the initial position and the first pressing member 233 is arranged at the first position before the flowchart shown in FIG. 14 is executed.

After the leading edge of the medium passes the position of the second medium sensor 115 in step S204, the detection unit 162 detects the thickness of the medium being transported (step S205). The detector 162 detects the thickness of the medium based on the ultrasonic signal received from the ultrasonic sensor 114 . Ultrasonic waves transmitted by the ultrasonic transmitter 114a and transmitted through a medium are attenuated by the medium, and the thicker the medium, the greater the attenuation of the ultrasonic waves. The medium transport device 100 stores in the storage device 150 in advance a table that defines the relationship between the magnitude of the ultrasonic waves received by the ultrasonic receiver 114b, that is, the signal value of the ultrasonic signal, and the thickness of the medium. The detection unit 162 refers to the table stored in the storage device 150 and identifies the thickness of the medium corresponding to the signal value of the received ultrasonic signal.

Further, based on the ultrasonic signal received from the ultrasonic sensor 114, the detection unit 162 may further determine whether or not double feeding of media has occurred. When a plurality of media are overlapped and conveyed, ultrasonic waves that pass through the media are attenuated by air layers between the overlapped and conveyed media. Therefore, the detection unit 162 can determine whether or not double feeding of media has occurred based on whether or not the signal value of the ultrasonic signal is equal to or less than the double feeding threshold. The double feed threshold is set to a value between the signal value of the ultrasonic signal when one sheet is conveyed and the signal value of the ultrasonic signal when two sheets are conveyed. When the detection unit 162 determines that double feeding of media has occurred, the control unit 161 stops the motor 141 to stop conveying and ejecting the media. Note that the control unit 161 may stop the medium reading process after discharging the medium that is currently being conveyed. Further, the control unit 161 may drive the motor 141 to control each roller so that the medium remaining in the conveying path is reversely fed, temporarily returned to the mounting table 103, and then re-fed (separated). . This eliminates the need for the user to re-mount the medium on the mounting table 103 and re-feed the medium, and the control unit 161 can improve convenience for the user. Further, the control unit 161 may notify the user by displaying information indicating the occurrence of double feeding of media on the display device 106 or by transmitting the information to the information processing device via the interface device 142 .

Also, the detection unit 162 may detect the thickness of the medium using a thickness sensor other than the ultrasonic sensor 114 . The thickness sensor is arranged at the position where the ultrasonic sensor 114 is arranged. Note that the thickness sensor may be arranged at any position on the medium transport path. The thickness sensor includes, for example, a light emitter and light receiver pair provided on one side of the media transport path and a light emitter and light receiver pair provided on the other side. The reflected light sensor measures the time from when one pair irradiates light on one side of the medium until it receives the reflected light, and when the other pair irradiates light on the other side of the medium and receives the reflected light. The distance between each pair and each surface of the medium is detected from the time until light is received. The reflected light sensor produces a thickness signal indicating the thickness of the distance between the two pairs minus each detected distance. The medium transport device 100 stores in the storage device 150 in advance a table that defines the relationship between the signal value of the thickness signal and the thickness of the medium. The detection unit 162 refers to the table stored in the storage device 150 and identifies the thickness of the medium corresponding to the signal value of the received thickness signal. Note that the thickness sensor is not limited to one that uses light, and any other sensor capable of detecting the thickness of the medium, such as a pressure sensor or a thickness sensor using a contact piece, may be used as the thickness sensor. may In addition, instead of the thickness detected by the sensor, or in addition to the thickness detected by the sensor, the detection unit 162 specifies the thickness based on the setting specified by the user (designation of thick or thin paper or designation of medium type such as postcard). You may

Next, the pressing control section 163 controls the first pressing member 233 based on the thickness of the medium detected by the detecting section 162 (step S206). The pressing control unit 163 controls the second motor 238 based on the detected thickness of the medium, moves the angle changing member 239, and changes the inclination angle of the first contact surface 233a of the first pressing member 233. change. For example, when the thickness of the medium is greater than the thickness threshold, the pressing control section 163 does not move the angle changing member 239 from the initial position and places the first pressing member 233 at the first position. On the other hand, when the thickness of the medium is equal to or less than the thickness threshold, the pressing control section 163 moves the angle changing member 239 from the initial position to the moving position, and arranges the first pressing member 233 at the second position. The thickness threshold is set, for example, to a value between the thickness of thin paper, which easily wrinkles, and the thickness of PPC paper, which does not easily wrinkle.

Note that the pressure control unit 163 adjusts the position of the angle changing member 239 in three or more stages so that the inclination angle of the first contact surface 233a increases as the thickness of the medium decreases (the thinner the medium). You can change it with As a result, the pressure control unit 163 can more finely adjust the magnitude of the outward force in the width direction A2 for each medium, and can more appropriately suppress the occurrence of wrinkles in the medium.

In this way, the angle changing member 239 changes the inclination angle of the first contact surface 233a of the first pressing member 233 based on the thickness of the medium detected by the detecting section 162. As a result, the medium conveying device properly conveys PPC paper, etc., which is less likely to wrinkle, according to the initial settings of the device, while pulling the thin paper, which is more likely to wrinkle, more strongly toward the outside in the width direction A2, thereby reducing wrinkles in the thin paper. can be suppressed.

It should be noted that regardless of the thickness of the medium, when the user instructs to change the inclination angle of the first contact surface 233a using the operation device 105 or the information processing device, the pressure control unit 163 The inclination angle of the contact surface 233a may be changed.

Further, the control unit 161 determines whether or not the medium included in the input image has wrinkles, and if it determines that the medium included in the input image has wrinkles, corrects the input image to remove the wrinkles. may

In that case, the control unit 161 uses machine learning technology, for example, to determine whether or not the medium included in the input image has wrinkles. The medium conveying device 100 stores in the storage device 150 in advance a discriminator that has been pre-learned so as to output the degree of wrinkles of the medium included in the image when the image is input. This classifier is pre-trained, such as by deep learning, using sample images containing wrinkled media and/or sample images without wrinkled media. The discriminator is trained such that the higher the probability that the medium included in the input image has wrinkles, the higher the output value. The control unit 161 inputs an input image to the discriminator and acquires an output value output from the discriminator. The control unit 161 determines that the medium included in the input image has wrinkles when the output value is equal to or greater than the threshold, and determines that the medium included in the input image does not have wrinkles when the output value is less than the threshold. judge.

When the control unit 161 determines that the medium included in the input image has wrinkles, the control unit 161 corrects the input image so as to remove the wrinkles by applying a filter such as a smoothing filter or a Gaussian filter to the input image. .

Further, when the control unit 161 determines that the medium included in the input image has wrinkles, the control unit 161 displays information suggesting a change in the inclination angle of the first contact surface 233a on the display device 106 or via the interface device 142. may be notified to the user by transmitting to the information processing device.

As described in detail above, the medium conveying device can convey the medium satisfactorily even when the inclination angle of the first contact surface 233a of the first pressing member 233 is changed based on the thickness of the medium to be conveyed. became possible.

FIGS. 15(A), (B), FIGS. 16(A), and (B) are schematic diagrams for explaining the first pressing member 333 in the medium conveying device according to still another embodiment. 15(A) and 16(A) are schematic diagrams of the first pressing member 333 viewed from the side, and FIGS. It is a schematic diagram seen from. 15(A) and (B) show the first pressing member 333 arranged at the first position, and FIGS. 16(A) and (B) show the first pressing member 333 arranged at the second position different from the first position. 1 pressing member 333 is shown.

As shown in FIGS. 15A, 15B, 16A, and 16B, the medium transport device according to this embodiment has a first pressing member 333 instead of the first pressing member 133. , and further includes a second motor 338 and a pressing force changing member 339 .

The first pressing member 333 has a first contact surface 333a, a first elastic member 333b and a holding member 333c. The first contact surface 333a contacts and presses the second shaft 132 similarly to the first contact surface 133a. The first contact surface 333a is an example of an inclined surface, and is formed so as to incline with respect to the medium transport surface, particularly so as to incline downward toward the downstream side. The first elastic member 333b has the same configuration as the first elastic member 133b, and applies an upward pressing force along the height direction A3 to the first contact surface 333a. However, one end of the first elastic member 333b is supported not by the lower housing 101 but by the holding member 333c. The holding member 333c is provided to support one end of the first elastic member 333b.

The second motor 338 generates a third driving force for rotating the cam member of the pressing force changing member 339, which will be described later.

The pressing force changing member 339 is an example of a pressing force changing unit. The pressing force changing member 339 rotates the cam member in the direction of arrow A9 by the third driving force generated by the second motor 338, and moves the first driven roller 117 by the first pressing member 333 to the first conveying roller 116 side. It is provided so as to change the pressing force to press on. The pressing force changing member 339 has a cam member 339a and a rotating shaft 339b. The cam member 339a is, for example, a plate cam that is rotatable by the third driving force generated by the second motor 338 . The cam member 339a is provided so as to contact the surface of the holding member 333c opposite to the surface supporting the first elastic member 333b. The rotating shaft 339 b is the rotating shaft of the cam member 339 a and is attached to the second motor 338 .

When the device is started, the cam member 339a of the pressing force changing member 339 is placed at the initial position shown in FIGS. 15(A) and 15(B), and the first pressing member 333 is placed at the first position. On the other hand, when the second motor 338 rotates to generate the third driving force, the cam member 339a rotates to the movement position shown in FIGS. 2 position. As the cam member 339a rotates, the holding member 333c of the first pressing member 333 moves upward, and the force with which the first elastic member 333b presses the first pressing member 333 increases. As a result, the force with which the first pressing member 333 presses the second shaft 132 increases, and the force with which the first driven roller 117 presses the first conveying roller 116 increases.

It should be noted that the pressing force changing member 339 may be provided so as to change the pressing force of the first pressing member 333 by rotating manually by the operator instead of using the third driving force from the second motor 338 . As described above, the outward force in the width direction A2 applied to the conveyed medium varies from apparatus to apparatus. In the medium conveying device, the pressing force changing member 339 is provided so that the pressing force of the first pressing member 333 can be changed. You can adjust the size.

In particular, since the pressing force changing member 339 has a simpler structure than the angle changing member 239, the medium conveying device can be conveyed individually for each device while suppressing an increase in device cost. It is possible to adjust the outward force applied to the medium in the width direction A2.

The medium conveying device according to the present embodiment executes medium reading processing similar to the medium reading processing shown in FIG. In this case, the cam member 339a of the pressing force changing member 339 is placed at the initial position, and the first pressing member 333 is placed at the first position before the flowchart shown in FIG. 14 is executed.

However, in step S205, the pressing control unit 163 controls the second motor 338 based on the detected thickness of the medium to rotate the cam member 339a so that the first pressing member 333 presses the first driven roller 117. to the first conveying roller 116 side is changed. For example, when the thickness of the medium is greater than the thickness threshold, the pressing control section 163 does not rotate the cam member 339a from the initial position and places the first pressing member 333 at the first position. On the other hand, when the thickness of the medium is equal to or less than the thickness threshold, the pressing control section 163 rotates the cam member 339a from the initial position to the moving position, and places the first pressing member 333 at the second position.

Note that the pressing control unit 163 changes the position of the cam member 339a in three or more steps so that the pressing force of the first pressing member 333 increases as the thickness of the medium decreases (the thinner the medium). You may As a result, the pressure control unit 163 can more finely adjust the magnitude of the outward force in the width direction A2 for each medium, and can more appropriately suppress the occurrence of wrinkles in the medium.

In this manner, the pressing force changing member 339 adjusts the pressing force of the first pressing member 333 to press the first driven roller 117 toward the first conveying roller 116 based on the thickness of the medium detected by the detection unit 162. change. As a result, the medium conveying device properly conveys PPC paper, etc., which is less likely to wrinkle, according to the initial settings of the device, while pulling the thin paper, which is more likely to wrinkle, more strongly toward the outside in the width direction A2, thereby reducing wrinkles in the thin paper. can be suppressed.

It should be noted that regardless of the thickness of the medium, the pressing force control unit 163 changes the pressing force when the user instructs to change the pressing force by the pressing force changing member 339 using the operation device 105 or the information processing device. The pressing force by the member 339 may be changed.

Further, the control unit 161 determines whether or not the medium included in the input image has wrinkles, and if it determines that the medium included in the input image has wrinkles, corrects the input image to remove the wrinkles. Alternatively, the user may be notified of a proposal to change the pressing force.

As described in detail above, the medium conveying device can convey the medium satisfactorily even when the pressing force of the first pressing member 333 is changed based on the thickness of the medium to be conveyed.

FIG. 17 is a schematic diagram for explaining a support member 437 of a medium conveying device according to still another embodiment. 17 is a perspective view of the first driven roller 117 and the second shaft 132. FIG.

As shown in FIG. 17, a support member 437 is used instead of the support member 137, and the second shaft 437 is provided outside the two second driven rollers 120, i.e., at the end in the width direction A2 orthogonal to the medium transport direction. 132 is provided. A circular hole is formed in the support member 437, and the end of the second shaft 132 in the width direction A2 is inserted into the hole, whereby the support member 437 rotatably supports the second shaft 132. do. Thereby, the second shaft 132 is rotatably provided. On the other hand, the second driven roller 120 is fixed to the second shaft 132 so as to rotate with the rotation of the second shaft 132 .

Even when the support member 437 is used instead of the support member 137, the first pressure member 233 and the angle change member 239, or the first pressure member 333 and the pressure change member 339 are used instead of the first pressure member 133. may be used.

As described in detail above, the medium conveying device can satisfactorily convey the medium even when the second shaft 132 is rotatably provided.

18 and 19 are schematic diagrams for explaining a transport mechanism 530 of a medium transport device according to still another embodiment. FIG. 18 is a schematic diagram of the transport mechanism 530 viewed from above. FIG. 19 is a schematic diagram of the transport mechanism 530 viewed from the side.

The medium transporting device according to the present embodiment has each part of the medium transporting device 100 . However, as shown in FIGS. 18 and 19, the medium transport device has a transport mechanism 530 instead of the transport mechanism 130. FIG. The transport mechanism 530 has a configuration similar to that of the transport mechanism 130 . However, the transport mechanism 530 has a second shaft 532 and a first pressing member 533 instead of the second shaft 132 and the first pressing member 133 .

The second shaft 532 has the same configuration as the second shaft 132. However, the second shaft 532 is inclined such that the central portion in the width direction A2 perpendicular to the medium conveying direction is located downstream of the end portions in the medium conveying direction A1. In particular, the second shaft 532 is angled to be curved. A first driven roller 117 is provided on the second shaft 532 so as to be rotatable along a direction perpendicular to the extending direction of the second shaft 532 . The second shaft 532 is non-rotatably provided, and the first driven roller 117 is rotatably provided with respect to the second shaft 532 . The second shaft 532 is arranged upstream from the first shaft 131 , and the first driven roller 117 is arranged upstream from the first conveying roller 116 .

The first pressing member 533 is arranged to abut on the second shaft 532 between the two first driven rollers 117, that is, at the central portion in the width direction A2 orthogonal to the medium conveying direction. The first pressing member 533 is provided so as to contact the lower side of the second shaft 532 so as to press the second shaft 532 toward the first shaft 131 side, that is, upward. The first pressing member 533 has a first contact surface 533a and a first elastic member 533b.

The first contact surface 533 a contacts the second shaft 532 and presses the second shaft 532 . The first contact surface 533a is formed parallel to the medium transport surface. The first elastic member 533 b has the same configuration as the first elastic member 133 b , and is provided so that one end is supported by the lower housing 101 and the other end is in contact with the first pressing member 533 . The first elastic member 533b applies an upward pressing force along the height direction A3 to the first contact surface 533a.

In this case also, the first driven rollers 117 having the second shaft 532 as the rotation axis rotate to convey the medium outward in the width direction A2, and the medium is conveyed so as to be pulled outward. Therefore, the occurrence of wrinkles in the medium is suppressed. On the other hand, the first shaft 131, which is the rotating shaft of the first conveying roller 116, is provided so as to extend linearly. As a result, the medium conveying device can secure the medium conveying force of the first conveying roller 116 and appropriately convey the medium.

Further, since the second shaft 532 is curved in advance, the first contact surface 533a of the first pressing member 533 does not need to be inclined. As a result, the medium conveying device can share the first pressing member 533 and the second pressing member 136, and can reduce the cost of the device.

Also when the second shaft 532 is used instead of the second shaft 132 , the first pressing member 333 and the pressing force changing member 339 may be used instead of the first pressing member 133 . Further, a support member 437 is used in place of the support member 137 to provide a rotatable second shaft 532 , and the second shaft 532 rotates as the first driven roller 117 rotates as the second shaft 532 rotates. may be fixed to

As described in detail above, the medium conveying device can satisfactorily convey the medium even when the second shaft 532 is inclined so as to be curved.

FIG. 20 is a schematic diagram for explaining a transport mechanism 630 of a medium transport device according to still another embodiment. FIG. 20 is a schematic diagram of the transport mechanism 630 viewed from above.

The medium transporting device according to the present embodiment has each part of the medium transporting device 100 . However, as shown in FIG. 20 , the medium transporting device has a transporting mechanism 630 instead of the transporting mechanism 130 . The transport mechanism 630 has a configuration similar to that of the transport mechanism 530 . However, the transport mechanism 630 has a second shaft 632 instead of the second shaft 532 . The second shaft 632 has a configuration similar to that of the second shaft 532 . However, the second shaft 632 is inclined so as to bend.

In this case also, the first driven rollers 117 having the second shaft 632 as the rotation axis rotate to convey the medium outward in the width direction A2, and the medium is conveyed so as to be pulled outward. Therefore, the occurrence of wrinkles in the medium is suppressed. On the other hand, the first shaft 131, which is the rotating shaft of the first conveying roller 116, is provided so as to extend linearly. As a result, the medium conveying device can secure the medium conveying force of the first conveying roller 116 and appropriately convey the medium.

Also, since the second shaft 632 is bent in advance, the first contact surface 533a of the first pressing member 533 need not be inclined. As a result, the medium conveying device can share the first pressing member 533 and the second pressing member 136, and can reduce the cost of the device.

Also when the second shaft 632 is used instead of the second shaft 132, the first pressing member 333 and the pressing force changing member 339 may be used instead of the first pressing member 133. Further, a support member 437 is used in place of the support member 137 to provide a rotatable second shaft 632 , and the second shaft 632 rotates as the first driven roller 117 rotates as the second shaft 632 rotates. may be fixed to

As described in detail above, the medium conveying device can satisfactorily convey the medium even when the second shaft 532 is inclined so as to bend.

21 and 22 are schematic diagrams for explaining a transport mechanism 730 of a medium transport device according to still another embodiment. 21 is a schematic diagram of the transport mechanism 730 viewed from above, and FIG. 22 is a schematic diagram of the transport mechanism 730 viewed from the side.

The medium transporting device according to the present embodiment has each part of the medium transporting device 100 . However, as shown in FIGS. 21 and 22, the medium transport device has a transport mechanism 730 instead of the transport mechanism 130. FIG. The transport mechanism 730 includes a first transport roller 716, a first driven roller 717, a second transport roller 719, a second driven roller 720, a first shaft 731, a second shaft 732, a first pressing member 733, a third shaft 734, It has a fourth shaft 735, a second pressing member 736, and the like.

A first conveying roller 716, a first driven roller 717, a second conveying roller 719, a second driven roller 720, a first shaft 731, a second shaft 732, a first pressing member 733, a third shaft 734, a fourth shaft 735 and The second pressing member 736 includes a first conveying roller 116, a first driven roller 117, a second conveying roller 119, a second driven roller 120, a first shaft 131, a second shaft 132, a first pressing member 133, and a third roller, respectively. It has the same configuration as the shaft 134 , the fourth shaft 135 and the second pressing member 136 .

However, the first conveying roller 716 , the second conveying roller 719 , the first shaft 731 and the third shaft 734 are provided in the lower housing 101 . On the other hand, the first driven roller 717 , the second driven roller 720 , the second shaft 732 , the first pressing member 733 , the fourth shaft 735 and the second pressing member 736 are provided on the upper housing 102 . The second shaft 732 and the first driven roller 717 are arranged downstream from the first shaft 731 and the first transport roller 716, respectively. On the other hand, the fourth shaft 735 and the second driven roller 720 are arranged upstream from the third shaft 734 and the second conveying roller 719, respectively.

The second shaft 732 is provided so as to extend straight in the width direction A2. The first pressing member 733 is an example of a second pressing portion, and is provided so as to contact the upper side of the second shaft 732 so as to press the second shaft 732 toward the first shaft 731 side, that is, downward. . The first pressing member 733 has a first contact surface 733a and a first elastic member 733b. The first contact surface 733a is formed parallel to the medium transport surface. The first elastic member 733 b has the same configuration as the first elastic member 133 b , and is provided so that one end is supported by the upper housing 102 and the other end is in contact with the back side of the first pressing member 733 . The first elastic member 733b applies a downward pressing force along the height direction A3 to the first contact surface 733a.

The fourth shaft 735 is provided so as to extend substantially parallel to the width direction A2. The second pressing member 736 is an example of a pressing portion, and is provided to contact the upper side of the fourth shaft 735 so as to press the fourth shaft 735 toward the third shaft 734 side, that is, downward. The second pressing member 736 has a second contact surface 736a and a second elastic member 736b. The second contact surface 736a is an example of an inclined surface, and is formed so as to incline with respect to the medium transport surface, particularly so as to incline upward toward the downstream side. As a result, when the second pressing member 736 presses the second shaft 732 from above along the height direction A3, the second pressing member 736 pushes the center portion of the second shaft 732 in the width direction A2 perpendicular to the medium transport direction. It is provided so as to press on the downstream side of A1. The second elastic member 736 b has the same configuration as the second elastic member 136 b , and is provided so that one end is supported by the upper housing 102 and the other end abuts the second pressing member 736 . The second elastic member 736b applies a downward pressing force to the second contact surface 736a along the height direction A3 orthogonal to the medium transport surface.

As a result, the fourth shaft 735 is curved such that the central portion in the width direction A2 is arranged on the downstream side and the end portion in the width direction A2 is arranged on the upstream side. Therefore, each of the second driven rollers 720 having the rotation axis of the fourth shaft 735 rotates to convey the medium outward in the width direction A2, and the medium is conveyed so as to be pulled outward. , the occurrence of wrinkles in the medium is suppressed.

In particular, the second driven roller 720 provided above the second conveying roller 719 is arranged upstream of the second conveying roller 719, and the second contact surface 736a of the second pressing member 736 The central portion of the shaft 735 in the width direction A2 is pressed downward. Therefore, if the second pressing member 736 does not press the central portion of the fourth shaft 735 in the width direction A2 toward the downstream side, the fourth shaft 735 is arranged to release the pressing force of the second elastic member 736b. It curves so that the central portion in the width direction A2 is arranged on the upstream side. As a result, each of the second driven rollers 720 having the fourth shaft 735 as a rotation axis rotates to convey the medium inward in the width direction A2, and the medium is conveyed so as to be pressed inward. . Therefore, wrinkles are likely to occur in the medium. In the medium conveying device, the second pressing member 736 presses the central portion of the fourth shaft 735 in the width direction A2 to the downstream side, so that it is possible to satisfactorily suppress the occurrence of wrinkles in the medium.

On the other hand, the first driven roller 717 provided above the first conveying roller 716 is arranged downstream of the first conveying roller 716, and the first contact surface 733a of the first pressing member 733 The central portion of the shaft 732 in the width direction A2 is pressed downward. Therefore, the second shaft 732 is curved such that the central portion in the width direction A2 is arranged on the downstream side so as to relieve the pressing force of the first elastic member 733b. As a result, the second shaft 732 curves such that the center portion in the width direction A2 is arranged on the downstream side and the end portions in the width direction A2 are arranged on the upstream side. Therefore, each of the first driven rollers 717 having the second shaft 732 as a rotation axis rotates so as to convey the medium outward in the width direction A2, and the medium is conveyed so as to be pulled outward. , the occurrence of wrinkles in the medium is suppressed.

As described above, the first contact surface 733a of the first pressing member 733 is formed parallel to the medium transport surface. Therefore, the first pressing member 733 presses the center portion of the second shaft 732 in the width direction A2 orthogonal to the medium conveying direction downward along the height direction A3, that is, to the first shaft 731 side. As a result, the first pressing member 133 prevents the second shaft 132 from excessively curving such that the central portion in the width direction A2 is arranged on the downstream side, and excessive outward force is applied to the medium. damage can be suppressed.

On the other hand, the first shaft 731, which is the rotating shaft of the first conveying roller 716, and the third shaft 734, which is the rotating shaft of the second conveying roller 719, are provided so as to extend straight. As a result, the medium conveying device can secure the medium conveying force of the first conveying roller 716 and the second conveying roller 719 and appropriately convey the medium.

Also when the transport mechanism 730 is used instead of the transport mechanism 130, the angle changing member 239 may be used, and the second pressing member 736 may be rotatably provided in the same manner as the first pressing member 233. Alternatively, the pressing force changing member 339 may be used, and the second pressing member 736 may be provided so as to be able to change the pressing force similarly to the first pressing member 333 . Further, a support member 437 is used instead of the support member 137 to provide a rotatable fourth shaft 735, and the fourth shaft 735 rotates as the second driven roller 720 rotates as the fourth shaft 735 rotates. may be fixed to Further, the fourth shaft 735 is inclined to be curved like the second shaft 532, and the second contact surface 736a of the second pressing member 736 is similar to the second contact surface 136a of the second pressing member 136. , may be provided so as not to tilt. Alternatively, the fourth shaft 735 is inclined to bend like the second shaft 632, and the second contact surface 736a of the second pressing member 736 is similar to the second contact surface 136a of the second pressing member 136. , may be provided so as not to tilt.

As described in detail above, the medium conveying device can satisfactorily convey the medium even when the second driven roller 720 is provided in the upper housing 102 .

In particular, the medium conveying device 100 can suppress the occurrence of wrinkles in the medium around the second conveying roller 719 and the second driven roller 720 .

FIG. 23 is a diagram showing a schematic configuration of a processing circuit 860 in a medium conveying device according to still another embodiment. The processing circuit 860 is used in place of the processing circuit 160 of the medium conveying device 100 and performs medium reading processing and the like instead of the processing circuit 160 . The processing circuit 860 has a control circuit 861, a detection circuit 862, a press control circuit 863, and the like. Each of these units may be composed of an independent integrated circuit, microprocessor, firmware, or the like.

The control circuit 861 is an example of a control section and has the same function as the control section 161. The control circuit 861 receives an operation signal from the operation device 105 or the interface device 142, a first medium signal from the first medium sensor 111, and a second medium signal from the second medium sensor 115, and based on the received information, It controls the motor 141 . Also, the control circuit 861 acquires an input image from the imaging device 118 and outputs it to the interface device 142 .

The detection circuit 862 is an example of a detection section and has the same function as the detection section 162. The detection circuit 862 receives an ultrasonic signal from the ultrasonic sensor 114 , detects the thickness of the medium based on the received ultrasonic signal, and outputs the detection result to the pressure control circuit 863 .

The pressing control circuit 863 is an example of a pressing control section and has the same function as the pressing control section 163. The pressure control circuit 863 receives the media thickness detection result from the detection circuit 862 and controls the

second motor

238 or 338 based on the media thickness.

As described in detail above, the medium conveying device can satisfactorily convey the medium even when the processing circuit 860 is used.

Although the preferred embodiments have been described above, the embodiments are not limited to these. For example, the medium transport device may be a printer that transports a print target or the like as a medium. In that case, the media transport device has a printing device instead of the imaging device 118 . The printing device is arranged at the position where the imaging device 118 is arranged. Since the medium conveying device can suppress the occurrence of wrinkles in the conveyed medium (printing object), it is possible to perform printing on the printing object satisfactorily.

100 medium conveying

device

116, 716 first conveying

rollers

117, 717 first driven

rollers

119, 719 second conveying

rollers

120, 720 second driven

rollers

131, 731

first shafts

132, 532, 632, 732 second shaft, 133, 233, 333, 533, 733 first pressing member, 134, 734 third shaft, 135, 735 fourth shaft, 136, 736 second pressing member, 162 detector, 239 angle changing member, 339 pressing force changing member

Claims

a motor that generates a driving force;
a first shaft linearly extending in a direction orthogonal to the medium transport direction and provided to rotate according to the driving force;
a transport roller that is fixed to the first shaft and transports a medium;
a second shaft;
a driven roller that is rotatably provided on the second shaft and that rotates following the conveying roller;
a pressing portion that presses a central portion of the second shaft in a direction orthogonal to the medium conveying direction to a downstream side in the medium conveying direction;
A medium transport device, comprising:
the second shaft is non-rotatably provided,
The medium transport device according to claim 1, wherein the driven roller is rotatably provided with respect to the second shaft.
The second shaft is rotatably provided,
The media transport device of claim 1, wherein the driven roller is fixed to the second shaft so as to rotate with rotation of the second shaft.
The second shaft is arranged upstream of the first shaft in the medium conveying direction,
4. The pressing portion according to any one of claims 1 to 3, wherein the pressing portion presses a central portion of the second shaft in a direction orthogonal to the medium transport direction toward the downstream side in the medium transport direction and toward the first shaft. Media transport.
a third shaft linearly extending in a direction orthogonal to the medium conveying direction and provided to rotate according to the driving force;
a second transport roller that is fixed to the third shaft and transports the medium;
a fourth shaft arranged downstream of the third shaft in the medium conveying direction;
a second driven roller that is rotatably provided on the fourth shaft and that rotates following the second conveying roller;
5. The apparatus according to claim 4, further comprising a second pressing portion that presses a central portion of the fourth shaft in a direction orthogonal to the medium transport direction toward the third shaft along a direction orthogonal to the medium transport surface. media transport device.
The pressing portion has an inclined surface that contacts the second shaft,
The medium conveying device according to any one of claims 1 to 5, further comprising an angle changer that changes the inclination angle of the inclined surface.
further comprising a detection unit that detects the thickness of the medium being conveyed,
The medium conveying device according to claim 6, wherein the angle changer changes the inclination angle of the inclined surface based on the detected thickness.
The medium conveying device according to any one of claims 1 to 5, further comprising a pressing force changing unit that changes the pressing force of the pressing unit to press the driven roller toward the conveying roller.
further comprising a detection unit that detects the thickness of the medium being conveyed,
The medium conveying device according to claim 8, wherein the pressing force changing unit changes the pressing force based on the detected thickness.
a motor that generates a driving force;
a first shaft linearly extending in a direction orthogonal to the medium transport direction and provided to rotate according to the driving force;
a transport roller that is fixed to the first shaft and transports a medium;
a second shaft inclined such that a central portion in a direction orthogonal to the medium conveying direction is located downstream of the end portion in the medium conveying direction;
a driven roller that is rotatably provided on the second shaft and that rotates following the conveying roller;
A medium transport device, comprising: