MEDIUM CONVEYING APPARATUS

Abstract

A medium conveying apparatus includes a motor, a first shaft, a conveyance roller, a second shaft, a driven roller, and a presser. The motor generates a driving force. The first shaft is rotated by the driving force. The first shaft extends linearly in a direction perpendicular to a medium conveyance direction. The conveyance roller is fixed to the first shaft to convey a medium. The driven roller is mounted on the second shaft to rotate following the conveyance roller. The presser presses a center portion of the second shaft in a direction perpendicular to the medium conveyance direction to a downstream side in the medium conveyance direction.

Description

BACKGROUND

Technical Field

Embodiments of the present disclosure relate to a medium conveying apparatus, and in particular, relate to a medium conveying apparatus including a conveyance roller and a driven roller.

Related Art

In general, a medium conveying apparatus such as a scanner generates an image by capturing an image of a medium conveyed by a conveyance roller. In such a medium conveying apparatus, if wrinkles occur in the medium being conveyed, noise may be included in the image captured from the medium.

For example, a document conveying apparatus includes two or more document conveyance rollers that convey a document and two or more driven rollers facing the document conveyance rollers. In the document conveying apparatus, a document conveyance roller shaft supports the document conveyance rollers. A bearing rotatably supports the document conveyance roller shaft at a center portion of the document conveyance roller shaft in the axial direction. The bearing is disposed downstream in a document conveyance direction from bearings rotatably supporting the document conveyance roller shaft at end portions of the document conveyance roller shaft. The document conveyance roller shaft is a single document conveyance roller shaft, and is bent toward the downstream side in the document conveyance direction and rotatably supported by the bearing at the center portion.

In addition, a medium conveying apparatus includes a drive roller and a driven roller. The drive roller is rotationally driven and conveys a medium. The driven roller follows the drive roller to rotate while nipping the medium between the drive roller and the driven roller. The medium conveying apparatus includes pressing members and spacers. The pressing members are disposed on one shaft end side and the other shaft end side of a rotation shaft of the driven roller and press the rotation shaft in a direction in which the driven roller comes into contact with the drive roller. Each of the spacers is interposed between the rotation shaft and corresponding one of the pressing members.

SUMMARY

According to an embodiment of the present disclosure, a medium conveying apparatus includes a motor, a first shaft, a conveyance roller, a second shaft, a driven roller, and a presser. The motor generates a driving force. The first shaft is rotated by the driving force. The first shaft extends linearly in a direction perpendicular to a medium conveyance direction. The conveyance roller is fixed to the first shaft and conveys a medium. The driven roller is mounted on the second shaft to rotate following the conveyance roller. The presser presses a center portion of the second shaft in a direction perpendicular to the medium conveyance direction to a downstream side in the medium conveyance direction.

According to another embodiment of the present disclosure, a medium conveying apparatus includes a motor, a first shaft, a conveyance roller, a second shaft, and a driven roller. The motor generates a driving force. The first shaft is rotated by the driving force. The first shaft extends linearly in a direction perpendicular to a medium conveyance direction. The conveyance roller is fixed to the first shaft and conveys a medium. The second shaft is inclined such that a center portion of the second shaft in a direction perpendicular to the medium conveyance direction is located downstream from end portions of the second shaft in the medium conveyance direction. The driven roller is mounted on the second shaft to rotate following the conveyance roller.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of embodiments of the present disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view illustrating a medium conveying apparatus according to an embodiment of the present disclosure;

FIG. 2 is a view illustrating a conveyance path inside the medium conveying apparatus;

FIG. 3 is a schematic view illustrating a conveyance mechanism;

FIG. 4 is a schematic view illustrating first driven rollers and the like;

FIG. 5 is a schematic view illustrating the first driven roller and the like;

FIG. 6 is a schematic view illustrating a first pressing member;

FIGS. 7A and 7B are schematic views illustrating the first pressing member;

FIG. 8 is a schematic view illustrating an operation of the conveyance mechanism;

FIG. 9 is a schematic view illustrating the operation of the conveyance mechanism;

FIG. 10 is a block diagram illustrating a general configuration of the medium conveying apparatus;

FIG. 11 is a diagram illustrating a general configuration of a storage device and a processing circuit;

FIG. 12 is a flowchart illustrating an example of an operation in a medium reading process;

FIGS. 13A and 13B are schematic views illustrating another first pressing member;

FIG. 14 is a flowchart illustrating an example of an operation in another medium reading process;

FIGS. 15A and 15B are schematic views illustrating another first pressing member;

FIGS. 16A and 16B are schematic views illustrating another first pressing member;

FIG. 17 is a schematic view illustrating another support member;

FIG. 18 is a schematic view illustrating another conveyance mechanism;

FIG. 19 is a schematic view illustrating the conveyance mechanism of FIG. 18 viewed from the lateral side;

FIG. 20 is a schematic view illustrating another conveyance mechanism;

FIG. 21 is a schematic view illustrating another conveyance mechanism;

FIG. 22 is a schematic view illustrating the conveyance mechanism of FIG. 21 viewed from the lateral side; and

FIG. 23 is a diagram illustrating a general configuration of another processing circuit.

The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Also, identical or similar reference numerals designate identical or similar components throughout the several views.

DETAILED DESCRIPTION

In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result.

Referring now to the drawings, embodiments of the present disclosure are described below. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Below, a medium conveying apparatus, a control method, and a control program according to one aspect of the present disclosure will be described with reference to the drawings. However, it should be noted that the technical scope of the present embodiment is not limited to these embodiments, but also includes embodiments described in the claims and equivalents thereof.

FIG. 1 is a perspective view of a medium conveying apparatus 100 employed as an image scanner. The medium conveying apparatus 100 conveys a medium, which is a document, and captures an image of the medium. The medium includes a sheet, thin paper, thick paper, a card, an envelope, and the like. The medium conveying apparatus 100 may be a facsimile apparatus, a copying machine, a printer 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 apparatus 100 may be a printer or the like.

The medium conveying apparatus 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, an arrow A1 indicates a medium conveyance direction, an arrow A2 indicates a width direction perpendicular to the medium conveyance direction, and an arrow A3 indicates a height direction perpendicular to a medium conveyance surface. In the following, the term “upstream” refers to upstream in the medium conveyance direction A1, and “downstream” refers to downstream in the medium conveyance direction A1.

The upper housing 102 is arranged at a position covering an upper surface of the medium conveying apparatus 100, and is rotatably engaged with the lower housing 101 by a hinge H such that the upper housing 102 can be opened and closed when a medium gets stuck or when the inside of the medium conveying apparatus 100 is cleaned.

The mounting table 103 engages with the lower housing 101 and a medium to be fed and conveyed is placed on the mounting table 103. The discharge table 104 is engaged with the upper housing 102 and a discharged medium is placed on the discharge table 104. Note that the discharge table 104 may be engaged with the lower housing 101.

The operation device 105 includes an input device such as a button and an interface circuit that acquires a signal from the input device. The operation device 105 receives an input operation by a user, and outputs an operation signal in accordance with the input operation by the user. The display device 106 includes a display and an interface circuit. The display includes a liquid crystal, an organic Electro-Luminescence (EL) display, and the like. The interface circuit outputs image data to the display, and the image data is displayed on the display.

FIG. 2 is a diagram for explaining a conveyance path inside the medium conveying apparatus 100.

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

Note that the number of each of the feeding roller 112, the separation roller 113, the first conveyance roller 116, the first driven roller 117, the second conveyance roller 119, and/or the second driven roller 120 is not limited to one, and a plurality of each of these components may be provided. In this case, each of the plurality of feeding rollers 112, separation rollers 113, first conveyance rollers 116, first driven rollers 117, second conveyance rollers 119, and/or second driven rollers 120 are arranged side by side with intervals in the width direction A2.

An upper surface of the lower housing 101 forms a lower guide 101a of a conveyance path of the medium, and a lower surface of the upper housing 102 forms an upper guide 102a of the conveyance path of the medium. The lower guide 101a forms a medium conveyance surface.

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

The feeding roller 112 is provided in the lower housing 101, and sequentially separates and feeds media placed on the mounting table 103 from the bottommost medium. The separation roller 113 is a so-called brake roller or a retard roller, is provided in the upper housing 102, is arranged facing the feeding roller 112, and rotates in a direction opposite to a medium feeding direction. Note that the feeding roller 112 may be provided in the upper housing 102, the separation roller 113 may be provided in the lower housing 101, and the feeding roller 112 may sequentially feed media placed on the mounting table 103 from the uppermost medium.

The ultrasonic sensor 114 is arranged downstream from the feeding roller 112 and the separation roller 113 and upstream from the first conveyance 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, and are arranged in the vicinity of the conveyance path of the medium to face each other with the conveyance path sandwiched therebetween. The ultrasonic transmitter 114a emits ultrasonic waves. The ultrasonic receiver 114b receives an ultrasonic wave transmitted by the ultrasonic transmitter 114a and passed through the medium, and generates and outputs an ultrasonic signal that is an electrical signal in accordance with the received ultrasonic wave. Note that the ultrasonic transmitter 114a may be arranged in the lower housing 101, and the ultrasonic receiver 114b may be arranged in the upper housing 102.

The second medium sensor 115 is arranged downstream from the feeding roller 112 and the separation roller 113 and upstream from the first conveyance roller 116 and the first driven roller 117, and detects a medium conveyed to the position where the second medium sensor 115 is arranged. The second medium sensor 115 includes a light emitter and a light receiver provided on one side with respect to the medium conveyance path, and a light guide provided at a position facing the light emitter and the light receiver with the medium conveyance path sandwiched therebetween. The light emitter is a Light Emitting Diode (LED) or the like, and emits light toward the medium conveyance path. The light receiver receives the light emitted by the light emitter and guided by the light guide. When a medium is present at a position facing the second medium sensor 115, the light emitted from the light emitter is blocked by the medium, and thus, the light receiver does not detect the light emitted from the light emitter. Based on the intensity of the received light, the light receiver generates and outputs a second medium signal whose signal value changes between a state where the medium is present at the position of the second medium sensor 115 and a state where the medium is not present at the position of the second medium sensor 115.

Note that a reflective member such as a mirror may be used instead of the light guide. The light emitter and the light receiver may be provided facing each other with the medium conveyance path sandwiched therebetween. Further, the second medium sensor 115 may detect the presence of the medium by a contact detection sensor or the like, through which a predetermined current flows when the medium contacts the contact detection sensor and when the medium does not contact the contact detection sensor.

The first conveyance roller 116 and the first driven roller 117 are examples of a conveyance roller and a driven roller, respectively, and are arranged facing each other downstream from the feeding roller 112. The first conveyance roller 116 is provided in the upper housing 102 and conveys a medium fed by the feeding roller 112 and the separation roller 113 to the imaging device 118. The first driven roller 117 is provided in the lower housing 101 below the first conveyance roller 116 and rotates following the first conveyance roller 116.

The imaging device 118 is arranged downstream of the first conveyance roller 116 and captures an image of the medium conveyed by the first conveyance roller 116. The imaging device 118 includes a first imaging device 118a and a second imaging device 118b that are arranged to face each other with the medium conveyance path sandwiched therebetween. The first imaging device 118a includes a line sensor using a Contact Image Sensor (CIS) of an equal-magnification optical system type and including imaging elements using a Complementary Metal Oxide Semiconductor (CMOS) linearly arrayed in a main scanning direction. Further, the first imaging device 118a includes a lens that forms an image on the imaging element, and an A/D converter that amplifies an electrical signal output from the imaging element and performs analog/digital (A/D) conversion. The first imaging device 118a captures an image of a front surface of the medium being conveyed, generates an input image, and outputs the generated input image, in accordance with control from a processing circuit described later.

Similarly, the second imaging device 118b includes a line sensor using a CIS of an equal-magnification optical system type that uses imaging elements using CMOS linearly arrayed in the main scanning direction. Further, the second imaging device 118b includes a lens that forms an image on the imaging element, and an A/D converter that amplifies an electrical signal output from the imaging element and performs analog/digital (A/D) conversion. The second imaging device 118b captures an image of a rear surface of the medium being conveyed, generates an input image, and outputs the generated input image, in accordance with control from a processing circuit described later.

Note that, in the medium conveying apparatus 100, only one of the first imaging device 118a and the second imaging device 118b may be provided to read only one side of the medium. Further, instead of the line sensor using a CIS of the equal-magnification optical system type including the imaging elements using CMOS, a line sensor may be utilized in which a CIS of an equal-magnification optical system type includes an imaging element using a Charge Coupled Device (CCD). Moreover, a line sensor of reduction optical system type including an imaging element using a CMOS or a CCD may be utilized.

The second conveyance roller 119 and the second driven roller 120 are arranged facing each other downstream of the imaging device 118. The second conveyance roller 119 is provided in the upper housing 102 and discharges, to the discharge table 104, a medium conveyed by the first conveyance roller 116 and the first driven roller 117 and of which an image is captured by the imaging device 118. The second driven roller 120 is provided in the lower housing 101 below the second conveyance roller 119 and rotates following the second conveyance roller 119.

When the feeding roller 112 rotates in the direction of an arrow A4 in FIG. 2, that is, in the medium feeding direction, a medium placed on the mounting table 103 is conveyed between the lower guide 101a and the upper guide 102a in the medium conveyance direction A1. While the medium is being fed, the separation roller 113 rotates in the direction of an arrow A5, that is, in a direction opposite to the medium feeding direction. When a plurality of media are placed on the mounting table 103, only a medium contacting the feeding roller 112 among the media placed on the mounting table 103 is separated from the plurality of media by the action of the feeding roller 112 and the separation roller 113. Thus, a medium other than the separated medium is prevented from being conveyed (double feeding is prevented).

The medium is fed between the first conveyance roller 116 and the first driven roller 117 while being guided by the lower guide 101a and the upper guide 102a. The first conveyance roller 116 rotates in the direction of an arrow A6 to feed the medium between the first imaging device 118a and the second imaging device 118b. The second conveyance roller 119 rotates in the direction of an arrow A7 to discharge the medium read by the imaging device 118 onto the discharge table 104.

FIG. 3 is a perspective view for explaining a conveyance mechanism 130 of the medium conveying apparatus 100.

As illustrated in FIG. 3, in addition to the first conveyance roller 116, the first driven roller 117, the second conveyance roller 119, and the second driven roller 120, the conveyance mechanism 130 includes a first shaft 131, a second shaft 132, a first pressing member 133, a third shaft 134, a fourth shaft 135, a second pressing member 136, and the like. In the example illustrated in FIG. 3, two members of each of the first conveyance roller 116, the first driven roller 117, the second conveyance roller 119, and the second driven roller 120 are arranged.

The first shaft 131 is provided to extend linearly in a straight manner in the width direction A2 perpendicular to the medium conveyance direction, and to be rotated by a driving force generated by a motor described later. The first conveyance rollers 116 are fixed to the first shaft 131 to rotate according to the rotation of the first shaft 131.

The second shaft 132 is provided to face the first shaft 131 and to extend substantially in parallel to the width direction A2 perpendicular to the medium conveyance direction. The first driven rollers 117 are provided on the second shaft 132 to be rotatable along a direction perpendicular to the direction in which the second shaft 132 extends.

The first pressing member 133 is an example of a presser, and is arranged to abut against the second shaft 132 between the two first driven rollers 117, that is, at a center portion in the width direction A2 perpendicular to the medium conveyance direction. In particular, the first pressing member 133 is preferably arranged at a center position of the arrangement positions of the first driven rollers 117 in the width direction A2. Thus, the two first driven rollers 117 are arranged line-symmetrically about the first pressing member 133, and a pressing force with which each of the first driven rollers 117 presses a corresponding one of the first conveyance rollers 116 is uniform. Therefore, it is possible to suppress the occurrence of skew of the medium in the medium conveying apparatus 100. The first pressing member 133 is provided to abut against the lower side of the second shaft 132 to press the second shaft 132 toward the first shaft 131, that is, to press the second shaft 132 upward.

The third shaft 134 is provided to extend linearly in a straight manner in the width direction A2 perpendicular to the medium conveyance direction, and to be rotated by a driving force generated by a motor described later. The second conveyance rollers 119 are fixed to the third shaft 134 to rotate according to the rotation of the third shaft 134.

The fourth shaft 135 is provided to face the third shaft 134 and to extend linearly in a straight manner in the width direction A2 perpendicular to the medium conveyance direction. The second driven rollers 120 are provided on the fourth shaft 135 to be rotatable along a direction perpendicular to the direction in which the fourth shaft 135 extends.

The second pressing member 136 is an example of a second presser, and is arranged to abut against the fourth shaft 135 between the two second driven rollers 120, that is, at a center portion in the width direction A2 perpendicular to the medium conveyance direction. In particular, the second pressing member 136 is preferably arranged at a center position between the arrangement positions of the second driven rollers 120 in the width direction A2. Thus, the two second driven rollers 120 are arranged line-symmetrically about the second pressing member 136, and a pressing force with which each of the second driven rollers 120 presses a corresponding one of the second conveyance rollers 119 is uniform. Therefore, it is possible to suppress the occurrence of skew in the medium by the medium conveying apparatus 100. The second pressing member 136 is provided to abut against the lower side of the fourth shaft 135 to press the fourth shaft 135 toward the third shaft 134, that is, to press the fourth shaft 135 upward.

FIGS. 4 and 5 are schematic views for explaining the first driven roller 117 and the second shaft 132. FIG. 4 is a perspective view of the first driven rollers 117 and the second shaft 132. FIG. 5 is a schematic view of the first driven roller 117 and the second shaft 132 viewed from the side.

As illustrated in FIGS. 4 and 5, the medium conveying apparatus 100 further includes support members 137. The support members 137 are formed of a resin or a metal, and are provided to support the second shaft 132 on outer sides of the two first driven rollers 117, that is, at end portions in the width direction A2 perpendicular to the medium conveyance direction. A notch portion (or an opening portion) into which the end portion of the second shaft 132 in the width direction A2 is inserted is formed in each of the support members 137. A support surface 137a formed in a planar shape is provided in the notch portion (or the opening portion). On the other hand, a supported surface 132a that is subjected to D-cutting is provided at the end portions of the second shaft 132 in the width direction A2. When the support surface 137a abuts against the supported surface 132a, the second shaft 132 is fixed by the support members 137 and is provided non-rotatably. On the other hand, the first driven rollers 117 are provided rotatably with respect to the second shaft 132.

The first driven rollers 117 are provided rotatably with respect to the second shaft 132, and thus, even when the center portion of the second shaft 132 in the width direction A2 is pressed downstream as described later, the second driven rollers 120 are driven by the first conveyance rollers 116 and rotate excellently.

FIGS. 6, 7A, and 7B are schematic views for explaining the first pressing member 133. FIG. 6 is a perspective view of the first pressing member 133 with the second shaft 132 placed thereon. FIG. 7A is a perspective view of the first pressing member 133 without the second shaft 132 placed thereon. FIG. 7B is a schematic view of the first pressing member 133 viewed from the side.

As illustrated in FIGS. 6, 7A, and 7B, the first pressing member 133 includes a first abutment surface 133a. The first abutment surface 133a abuts against the second shaft 132 and presses the second shaft 132. The first abutment surface 133a is an example of an inclined surface, and is formed inclined with respect to the medium conveyance surface parallel to the medium conveyance direction A1 and the width direction A2, in particular, inclined downward toward the downstream side. That is, when the first pressing member 133 presses the second shaft 132 from below along the height direction A3 perpendicular to the medium conveyance surface, the first pressing member 133 is provided to press the center portion of the second shaft 132 in the width direction A2 perpendicular to the medium conveyance direction toward the downstream side in the medium conveyance direction A1.

FIG. 8 is a schematic view for explaining an operation of the conveyance mechanism 130. FIG. 8 is a schematic view of the conveyance 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 illustrated in FIG. 8, the second shaft 132 is arranged upstream of the first shaft 131. Therefore, the first driven roller 117 provided below the first conveyance roller 116 is arranged upstream of the first conveyance roller 116. Accordingly, a nip surface between the first conveyance roller 116 and the first driven roller 117 is inclined downward toward the downstream side. The fourth shaft 135 is arranged downstream of the third shaft 134. Therefore, the second driven roller 120 provided below the second conveyance roller 119 is arranged downstream of the second conveyance roller 119. Accordingly, a nip surface between the second conveyance roller 119 and the second driven roller 120 is inclined downward toward the downstream side.

In FIG. 8, a path R indicates a path through which a front end of the medium being ideally conveyed passes. The nip surface of the first conveyance roller 116 and the first driven roller 117 is inclined downward toward the downstream side, such that the front end of the medium conveyed by the first conveyance roller 116 and the first driven roller 117 is conveyed downward. The front end of the medium contacts a glass surface G of the first imaging device 118a and is conveyed along the glass surface G. The nip surface of the second conveyance roller 119 and the second driven roller 120 is inclined upward toward the downstream side, such that the front end of the medium having passed between the first imaging device 118a and the second imaging device 118b is pulled by the second conveyance roller 119 and the second driven roller 120.

By conveying the front end of the medium along the glass surface G, the distance from the medium to each image sensor of the imaging device 118 is constant at imaging positions. Therefore, even when an equal-magnification optical system type CIS having a shallow depth of field is used, the occurrence of a focus shift is suppressed, and the imaging device 118 can obtain stable images. In particular, the distance from the medium to each imaging sensor of the imaging device 118 is constant in the width direction A2 (main scanning direction), and thus, the occurrence of unevenness in the horizontal direction within the input image is suppressed.

The front end of the medium is conveyed along the glass surface G, and thus, it is possible to clean the glass surface G, that is, remove foreign matter on the glass surface G with the front end 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. However, foreign matter adhering to the glass surface of the second imaging device 118b is likely to fall due to the weight of the foreign matter and adheres to the glass surface G of the first imaging device 118a. By conveying the medium along the glass surface G of the first imaging device 118a with the leading end of the medium arranged on a lower side, the medium conveying apparatus 100 can also remove foreign matter fallen from the glass surface of the second imaging device 118b.

As illustrated in FIG. 8, the first pressing member 133 includes a first elastic member 133b. The first elastic member 133b is a spring member such as a torsion coil spring, and is provided such that one end thereof is supported by the lower housing 101 and the other end abuts against the first pressing member 133. Note that the first elastic member 133b may be another spring member such as a leaf spring, a rubber member, or the like. The first elastic member 133b applies a pressing force to the first abutment surface 133a from below to above along the height direction A3.

The second pressing member 136 includes a second abutment surface 136a. The second abutment surface 136a abuts against the fourth shaft 135 and presses the fourth shaft 135. The second abutment surface 136a is formed to be parallel to the medium conveyance surface. Further, the second pressing member 136 includes a second elastic member 136b. The second elastic member 136b is a spring member such as a torsion recoil spring, and is provided such that one end thereof is supported by the lower housing 101 and the other end abuts against the second pressing member 136. Note that the second elastic member 136b may be another spring member such as a leaf spring, a rubber member, or the like. The second elastic member 136b applies a pressing force to the second abutment surface 136a from below to above along the height direction A3.

FIG. 9 is a schematic view for explaining an operation of the conveyance mechanism 130. FIG. 9 is a schematic view of the conveyance mechanism 130 viewed from above.

As described above, the first abutment surface 133a of the first pressing member 133 is inclined downward toward the downstream side, and the first elastic member 133b presses upward the center portion of the second shaft 132 in the width direction A2. Thus, the first pressing member 133 presses the center portion of the second shaft 132 in the width direction A2 perpendicular to the medium conveyance direction toward the first shaft 131, and also to the downstream side in the medium conveyance direction A1. Accordingly, as illustrated in FIG. 9, the second shaft 132 is bent 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 117 having the second shaft 132 as rotation shaft rotates to convey the medium outward in the width direction A2, and the medium is conveyed to be pulled outward.

Therefore, the medium conveying apparatus 100 can suppress the occurrence of wrinkles in the medium. When wrinkles occur in a medium being conveyed, noise may be produced and the gradation may decrease in an image captured from the medium, in particular, in a color image or a grayscale image. By suppressing the occurrence of wrinkles in the medium, the medium conveying apparatus 100 prevents the generation of noise and a deterioration of the gradation in the input image from the wrinkles in the medium.

In particular, the first driven roller 117 provided below the first conveyance roller 116 is arranged upstream of the first conveyance roller 116, and the first abutment surface 133a of the first pressing member 133 presses upward the center portion of the second shaft 132 in the width direction A2. If the first pressing member 133 would not press the center portion of the second shaft 132 in the width direction A2 toward the downstream side, the second shaft 132 would be bent such that the center portion of the second shaft 132 in the width direction A2 is arranged on the upstream side to release the pressing force by the first elastic member 133b. Thus, each of the first driven rollers 117 having the second shaft 132 as rotation shaft rotates to convey the medium inward in the width direction A2, and the medium is conveyed to be pressed inward. Therefore, wrinkles are more likely to occur in the medium. In the medium conveying apparatus 100, the first pressing member 133 presses the center portion of the second shaft 132 in the width direction A2 toward the downstream side, and thus, it is possible to suppress the occurrence of wrinkles in the medium in an excellent manner.

The second driven roller 120 provided below the second conveyance roller 119 is arranged downstream of the second conveyance roller 119, and the second abutment surface 136a of the second pressing member 136 presses upward the center portion of the fourth shaft 135 in the width direction A2. The fourth shaft 135 is bent such that the center portion in the width direction A2 is arranged on the downstream side to release the pressing force by the second elastic member 136b. Therefore, each of the second driven rollers 120 having the fourth shaft 135 as rotation shaft rotates to convey the medium outward in the width direction A2, and the medium is conveyed to be pulled outward. Thus, wrinkles are prevented from occurring in the medium.

As described above, the second abutment surface 136a of the second pressing member 136 is formed to be parallel to the medium conveyance surface. Therefore, the second pressing member 136 presses the center portion of the fourth shaft 135 in the width direction A2 perpendicular to the medium conveyance direction upward (toward the third shaft 134) along the height direction A3 perpendicular to the medium conveyance surface. Thus, the second pressing member 136 prevents the fourth shaft 135 from curving too much, and suppresses damage to the medium when a force directed outward is excessively applied to the medium.

In the medium conveying apparatus 100, the first shaft 131, which is the rotation shaft of the first conveyance roller 116, and the third shaft 134, which is the rotation shaft of the second conveyance roller 119, are provided to extend linearly in a straight manner. Thus, the medium conveying apparatus 100 secures a medium conveyance force by the first conveyance roller 116 and the second conveyance roller 119, and appropriately conveys the medium.

Similarly to the first pressing member 133, the second pressing member 136 presses the center portion of the fourth shaft 135 in the width direction A2 downstream, and may be bent such that the center portion of the fourth shaft 135 in the width direction A2 is arranged on the downstream side.

The first abutment surface 133a of the first pressing member 133 may be formed to be parallel to the medium conveyance surface, instead of being formed to be inclined with respect to the medium conveyance surface. In this case, the first elastic member 133b of the first pressing member 133 is provided to apply a force to the first pressing member 133 in a direction inclined with respect to the height direction A3, such that the first pressing member 133 presses the second shaft 132 downward in the medium conveyance direction A1.

FIG. 10 is a block diagram illustrating a general configuration of the medium conveying apparatus 100.

In addition to the above-described configuration, the medium conveying apparatus 100 further includes a motor 141, an interface device 142, a storage device 150, a processing circuit 160, and the like.

The motor 141 includes one motor or a plurality of motors, and generates a driving force for rotating the rotation shaft of the feeding roller 112, the rotation shaft of the separation roller 113, the first shaft 131, and the third shaft 134, in response to a control signal from the processing circuit 160. Thus, the motor 141 rotates the feeding roller 112, the separation roller 113, the first conveyance roller 116, and the second conveyance roller 119 to convey the medium.

The interface device 142 includes an interface circuit conforming to a serial bus such as a Universal Serial Bus (USB), and is electrically connected to an information processing device (for example, a personal computer, a mobile information terminal, and the like) to transmit and receive an input image and various types of information. Further, instead of the interface device 142, a communication unit including an antenna that transmits and receives a radio signal and a radio communication interface device that transmits and receives a signal via a radio communication line in accordance with a predetermined communication protocol may be used. The predetermined communication protocol is, for example, a wireless Local Area Network (LAN). The communication unit may include a wired communication interface device that transmits and receives a signal via a wired communication line in accordance with a communication protocol such as a wired LAN.

The storage device 150 includes a memory device such as a Random Access Memory (RAM) and a Read Only Memory (ROM), a fixed disk device such as a hard disk, or a portable storage device such as a flexible disk or an optical disk. The storage device 150 stores a computer program, a database, a table, or the like used for various types of processes in the medium conveying apparatus 100. The computer program may be installed in the storage device 150 from a computer-readable portable recording medium by using a known setup program or the like. For example, the portable recording medium is a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), and the like.

The processing circuit 160 operates based on a program stored in the storage device 150 in advance. For example, the processing circuit 160 is a Central Processing Unit (CPU). A digital signal processor (DSP), a large scale integration (LSI), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or the like may be used as the processing circuit 160.

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, and controls each of these components. The processing circuit 160 performs drive 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. The processing circuit 160 acquires an input image from the imaging device 118 and transmits the acquired input image to the information processing device via the interface device 142.

FIG. 11 is a diagram illustrating a general configuration of the storage device 150 and the processing circuit 160.

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

FIG. 12 is a flowchart illustrating an example of an operation in a medium reading process by the medium conveying apparatus 100.

Below, an example of the operation in the medium reading process by the medium conveying apparatus 100 will be described with reference to the flowchart illustrated in FIG. 12. The operation flow described below is mainly executed by the processing circuit 160 in cooperation with each element of the medium conveying apparatus 100, based on a program stored in the storage device 150 in advance.

First, when a user uses the operation device 105 or the information processing device to input an instruction for reading a medium, the control unit 161 waits until receiving, from the operation device 105 or the interface device 142, an operation signal instructing to read the medium (step S101).

Next, the control unit 161 acquires the first medium signal from the first medium sensor 111, and determines whether a medium is placed on the mounting table 103, based on the acquired first medium signal (step S102). If no medium is placed on the mounting table 103, the control unit 161 ends the series of steps.

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

Next, the control unit 161 waits until the front end 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 determines that the front end of the medium passes the position of the second medium sensor 115, when a signal value of the second medium signal changes from a value indicating that the medium is not present to a value indicating that the medium is present.

Next, the control unit 161 causes the imaging device 118 to capture an image of the medium, acquires an input image from the imaging device 118, and transmits the acquired input image to the information processing device via the interface device 142 to output the acquired input image (step S105).

Next, the control unit 161 determines whether a medium remains on the mounting table 103, based on the first medium signal received from the first medium sensor 111 (step S106). If a medium remains on the mounting table 103, the control unit 161 returns the processing to step S104 and repeats the processes of steps S104 to S106.

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

As described in detail above, in the medium conveying apparatus 100, by forming the first shaft 131, which is the rotation shaft of the first conveyance roller 116, in a straight manner and curving only the second shaft 132, which is the rotation shaft of the first driven roller 117, it is possible to secure the medium conveyance force while suppressing the occurrence of wrinkles in the medium. Therefore, the medium conveying apparatus 100 conveys the medium in an excellent manner.

In particular, the medium conveying apparatus 100 suppresses the occurrence of wrinkles in the medium between the feeding roller 112 and the separation roller 113 (separation unit) and the first conveyance roller 116 and the first driven roller 117 (conveyance unit).

The medium conveying apparatus 100 presses the center portion of the second shaft 132 in the width direction A2 by using the one first pressing member 133 in which the first abutment surface 133a is inclined, such that each of the first driven rollers 117 is rotated outward in the width direction A2. Thus, according to the medium conveying apparatus 100, it is possible to suppress the occurrence of wrinkles in the medium while suppressing an increase in device cost.

In the medium conveying apparatus 100, the first shaft 131, which is the rotation shaft (drive shaft) of the first conveyance roller 116 is provided to extend linearly in a straight manner without being bent. Therefore, the medium conveying apparatus 100 suppresses the occurrence of metal fatigue of the first shaft 131 and wear between the first shaft 131 and a bearing of the first shaft 131, and prevents a decrease in device life.

Generally, to maintain the stability of the medium conveyance force, the rotation shaft of the conveyance roller is preferably formed with a large shaft diameter (the thickness of the rotation shaft is increased) to reduce deflection due to the pressing force from the driven roller. If the shaft diameter of the rotation shaft of the conveyance roller is increased while the rotation shaft of the conveyance roller is bent, the reaction force applied to the rotation shaft of the conveyance roller increases, and the stability of the medium conveyance force is impaired. In particular, when a medium conveying apparatus supports the conveyance of a large medium such as an A3 sheet, the shaft forming the rotation shaft of each conveyance roller increases in length, and the reaction force applied to the shaft increases. On the other hand, if the shaft diameter of the rotation shaft of the conveyance roller is reduced (the thickness of the rotation shaft is decreased), the vibration of the conveyance roller while conveying the medium increases, which impairs the stability of the medium conveyance force. In the medium conveying apparatus 100, the first shaft 131, which is the rotation shaft of the first conveyance roller 116, extends linearly. Therefore, no reaction force is applied to the first shaft 131, and even if the first shaft 131 is formed thicker, the stability of the medium conveyance force is not impaired.

FIGS. 13A and 13B are schematic views for explaining a first pressing member 233 in a medium conveying apparatus according to another embodiment. FIGS. 13A and 13B are schematic views of the first pressing member 233 viewed from the side. FIG. 13A illustrates the first pressing member 233 arranged at a first position. FIG. 13B illustrates the first pressing member 233 arranged at a second position different from the first position.

As illustrated in FIGS. 13A and 13B, the medium conveying apparatus according to the present embodiment includes the first pressing member 233 instead of the first pressing member 133, and further includes a second motor 238 and an angle adjusting member 239.

The first pressing member 233 includes a first abutment surface 233a, a first elastic member 233b, a rotation shaft 233c, and an engaging unit 233d. Similarly to the first abutment surface 133a, the first abutment surface 233a abuts against the second shaft 132 and presses the second shaft 132. The first abutment surface 233a is an example of an inclined surface, and is formed inclined with respect to the medium conveyance surface, in particular, inclined downward toward the downstream side. The first elastic member 233b has a configuration similar to the first elastic member 133b, and applies a pressing force to the first abutment surface 233a from below to above along the height direction A3. The rotation shaft 233c is fixed to the lower housing 101 and rotatably (swingably) supports the first pressing member 233. That is, the first pressing member 233, in particular, the first abutment surface 233a, is provided rotatably (swingably) about the rotation shaft 233c. The engaging unit 233d is provided to engage with the angle adjusting member 239.

The second motor 238 generates a second driving force for slidably moving the angle adjusting member 239.

The angle adjusting member 239 is an example of an angle adjuster. The angle adjusting member 239 is provided to slidably move in the direction of an arrow A8 by the second driving force generated by the second motor 238 to adjust an inclination angle of the first abutment surface 233a of the first pressing member 233 with respect to the medium conveyance surface. The angle adjusting member 239 includes an engaged unit 239a. The engaged unit 239a supports the engaging unit 233d of the first pressing member 233 to hold the engaging unit 233d.

When the apparatus is powered on, the angle adjusting member 239 is arranged at an initial position illustrated in FIG. 13A, and the first pressing member 233 is arranged at the first position. When the second motor 238 rotates and generates the second driving force, the angle adjusting member 239 moves to a moved position illustrated in FIG. 13B, and the first pressing member 233 is arranged at the second position. The engaging unit 233d of the first pressing member 233 moves to the upper left while being held by the engaged unit 239a of the angle adjusting member 239, and the first pressing member 233 rotates (swings) around the rotation shaft 233c. Thus, the inclination angle of the first abutment surface 233a with respect to the medium conveyance surface is adjusted, and the force with which the first pressing member 233 presses the center portion of the second shaft 132 in the width direction A2 toward the downstream side increases.

The angle adjusting member 239 may be provided to be slidably moved manually by an operator, not by the second driving force from the second motor 238 to adjust the inclination angle of the first abutment surface 233a of the first pressing member 233 with respect to the medium conveyance surface. As described above, the first driven roller 117 is provided in the lower housing 101, and the first conveyance roller 116 is provided in the upper housing 102 that is provided openable and closable (rotatable) by the hinge H with respect to the lower housing 101. The hinge H, which is a rotation support portion of the upper housing 102, may wobble to a certain degree, and further, the arrangement position (rotation position) of the hinge H varies for each device. Therefore, a contact state between the first conveyance roller 116 and the first driven roller 117 varies for each device. Accordingly, the balance between a force component with which the first driven roller 117 pushes the first conveyance roller 116 in the medium conveyance direction A1 and a force component with which the first driven roller 117 pushes the first conveyance roller 116 in the height direction A3 varies for each device, and a force that is directed outward in the width direction A2 and applied to the medium being conveyed varies for each device. In the medium conveying apparatus, the angle adjusting member 239 is provided to adjust the inclination angle of the first abutment surface 233a, and thus, the magnitude of the force directed outward in the width direction A2 applied to the medium being conveyed may be adjusted for each device individually.

The angle adjusting member 239 adjusts the direction of the force while maintaining the overall magnitude of the force with which the first driven roller 117 presses against the first conveyance roller 116 constant. Therefore, the medium conveyance force during the conveyance of the medium is maintained constant. Accordingly, the medium conveying apparatus suppresses elongation and shrinkage of the medium in the sub-scanning direction within the input image.

FIG. 14 is a flowchart illustrating an example of the operation in the medium reading process by the medium conveying apparatus according to the present embodiment.

The processing in the flowchart illustrated in FIG. 14 is executed instead of the processing in the flowchart illustrated in FIG. 12. The processes in steps S201 to S204 and S207 to S209 of FIG. 14 are similar to the processes in steps S101 to S104 and S105 to S107 of FIG. 12, and thus, description thereof is omitted and only steps S205 and S206 will be described below. Note that, before the processing in the flowchart illustrated in FIG. 14 is executed, the angle adjusting member 239 is arranged at the initial position, and the first pressing member 233 is arranged at the first position.

After the front end of the medium passes the position of the second medium sensor 115 in step S204, the determination unit 162 determines the thickness of the medium being conveyed (step S205). The determination unit 162 determines the thickness of the medium, based on an ultrasonic signal received from the ultrasonic sensor 114. The ultrasonic wave transmitted by the ultrasonic transmitter 114a and passing through the medium is attenuated by the medium, and if the medium is thicker, the amount of attenuation of the ultrasonic wave increases. The medium conveying apparatus 100 stores in advance in the storage device 150 a table defining a relationship between the magnitude of the ultrasonic wave received by the ultrasonic receiver 114b, that is, the signal value of the ultrasonic signal, and the thickness of the medium. The determination 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.

The determination unit 162 may further determine, based on the ultrasonic signal received from the ultrasonic sensor 114, whether double feeding of media occurs. If a plurality of media are conveyed in an overlapping manner, the ultrasonic waves that pass through the media are attenuated by an air layer present between the media being conveyed in an overlapping manner. Therefore, the determination unit 162 can determine whether double feeding of media occurs, depending on whether the signal value of the ultrasonic signal is equal to or less than a double feeding threshold value. The double feeding threshold value 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. If the determination unit 162 determines that double feeding of media occurs, the control unit 161 stops conveyance and discharge of the media by stopping the motor 141. Note that the control unit 161 may stop the medium reading process after discharging the medium currently being conveyed. Further, the control unit 161 may drive the motor 141 and control each rollers such that a medium remaining in the conveyance path is reversely conveyed and temporarily returned to the mounting table 103, and then re-fed (separated). Accordingly, the user does not need to place the medium again on the mounting table 103 to re-feed the medium, and thus, the control unit 161 improves convenience for the user. The control unit 161 may notify the user of the occurrence of double feeding of media by displaying information indicating the occurrence of double feeding of media on the display device 106 or transmitting such information to the information processing device via the interface device 142.

The determination unit 162 may determine the thickness of the medium by using a thickness sensor other than the ultrasonic sensor 114. The thickness sensor is arranged at a position where the ultrasonic sensor 114 is arranged. Note that the thickness sensor may be arranged at any position on the medium conveyance path. For example, the thickness sensor includes a pair of a light emitter and a light receiver provided on one side with respect to the medium conveyance path, and a pair of a light emitter and a light receiver provided on the other side. A reflected light sensor detects a distance from each pair to a corresponding surface of the medium, from the time period from when one pair irradiates one surface of the medium with light until the reflected light is received, and the time period from when the other pair irradiates the other surface of the medium with light until the reflected light is received. The reflected light sensor generates a subtracted value obtained by subtracting each detected distance from the distance between the two pairs as a thickness signal indicating the thickness. The medium conveying apparatus 100 stores in advance in the storage device 150 a table defining a relationship between the signal value of the thickness signal and the thickness of the medium. The determination 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 a thickness sensor using light, and any other sensor detecting the thickness of a medium, such as a pressure sensor or a thickness sensor using a contact piece, and the like may be used as the thickness sensor. Instead of or in addition to the thickness detected by the sensor, the determination unit 162 may identify the thickness, based on a setting designated by the user (designation of thick paper or thin paper or designation of the type of medium such as a postcard).

Next, the press control unit 163 controls the first pressing member 233, based on the thickness of the medium detected by the determination unit 162 (step S206). Based on the determined thickness of the medium, the press control unit 163 controls the second motor 238, moves the angle adjusting member 239, and adjusts the inclination angle of the first abutment surface 233a of the first pressing member 233. For example, if the thickness of the medium is greater than the thickness threshold value, the press control unit 163 does not move the angle adjusting member 239 from the initial position and arranges the first pressing member 233 at the first position. On the other hand, if the thickness of the medium is equal to or less than the thickness threshold value, the press control unit 163 moves the angle adjusting member 239 from the initial position to the moved position, and arranges the first pressing member 233 at the second position. For example, the thickness threshold value is set to a value between the thickness of thin paper, which easily wrinkles, and the thickness of a PPC sheet, which does not easily wrinkle.

The press control unit 163 may adjust the position of the angle adjusting member 239 in three or more stages such that, with decreasing thickness of the medium (when the medium is thinner), the inclination angle of the first abutment surface 233a increases. Thus, the press control unit 163 more finely adjusts the magnitude of the force directed outward in the width direction A2 for each medium, and more appropriately suppresses the occurrence of wrinkles in the medium.

As described above, the angle adjusting member 239 adjusts the inclination angle of the first abutment surface 233a of the first pressing member 233, based on the thickness of the medium detected by the determination unit 162. Therefore, the medium conveying apparatus appropriately conveys a PPC sheet and the like, which is less likely to wrinkle, by conveying in accordance with the initial setting of the apparatus, and thin papers, which are more likely to wrinkle, by strongly pulling toward the outside in the width direction A2 to suppress the occurrence of wrinkles.

Note that, regardless of the thickness of the medium, if the user uses the operation device 105 or the information processing device to instruct an adjustment of the inclination angle of the first abutment surface 233a, the press control unit 163 may adjust the inclination angle of the first abutment surface 233a.

The control unit 161 may also determine whether the medium of the input image has wrinkles, and when determined that the medium of the input image has wrinkles, the control unit 161 may correct the input image to remove the wrinkles.

In this case, the control unit 161 utilizes, for example, machine learning technology to determine whether the medium of the input image has wrinkles. The medium conveying apparatus 100 stores in advance in the storage device 150 a classifying element trained in advance to output a degree to which a medium of an image has wrinkles when an image is input. The classifying element is trained in advance by using, for example, deep learning or the like using sample images of media having wrinkles and/or sample images of media having wrinkles. The classifying element is trained such that an output value increases when the chances that the medium of the input image has wrinkles increase. The control unit 161 inputs the input image to the classifying element and acquires an output value output from the classifying element. When the output value is equal to or greater than a threshold value, the control unit 161 determines that the medium of the input image has wrinkles, and when the output value is less than the threshold value, the control unit 161 determines that the medium of the input image does not have wrinkles.

When determining that the medium of the input image has wrinkles, the control unit 161 applies a filter such as a smoothing filter or a Gaussian filter to the input image for correcting the input image to remove the wrinkles.

Further, if the control unit 161 determines that the medium of the input image has wrinkles, the control unit 161 may display information suggesting an adjustment of the inclination angle of the first abutment surface 233a or may transmit such information to the information processing device via the interface device 142 to notify the user of the wrinkles in the medium.

As described in detail above, the medium conveying apparatus conveys the medium in an excellent manner, even when the inclination angle of the first abutment surface 233a of the first pressing member 233 is adjusted based on the thickness of the medium being conveyed.

FIGS. 15A and 15B and FIGS. 16A and 16B are schematic views for explaining a first pressing member 333 in a medium conveying apparatus according to still another embodiment. FIGS. 15A and 16A are schematic views of the first pressing member 333 viewed from the side. FIGS. 15B and 16B are schematic views of the first pressing member 333 viewed from the upstream side. FIGS. 15A and 15B illustrate the first pressing member 333 arranged at a first position. FIGS. 16A and 16B illustrate the first pressing member 333 arranged at a second position different from the first position.

As illustrated in FIGS. 15A and 15B and FIGS. 16A and 16B, the medium conveying apparatus according to the present embodiment includes the first pressing member 333 instead of the first pressing member 133, and further includes a second motor 338 and a pressing force adjusting member 339.

The first pressing member 333 includes a first abutment surface 333a, a first elastic member 333b, and a holding member 333c. Similarly to the first abutment surface 133a, the first abutment surface 333a abuts against the second shaft 132 and presses the second shaft 132. The first abutment surface 333a is an example of an inclined surface, and is formed inclined with respect to the medium conveyance surface, in particular, inclined downward toward the downstream side. The first elastic member 333b has a configuration similar to the first elastic member 133b, and applies, to the first abutment surface 333a, a pressing force from below to above along the height direction A3. 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 rotationally moving a cam member of the pressing force adjusting member 339 described later.

The pressing force adjusting member 339 is an example of a pressing force adjuster. The pressing force adjusting member 339 is provided to rotationally move the cam member in the direction of an arrow A9 by the third driving force generated by the second motor 338, and adjust the pressing force with which the first pressing member 333 presses the first driven roller 117 toward the first conveyance roller 116. The pressing force adjusting member 339 includes a cam member 339a and a rotation shaft 339b. For example, the cam member 339a is a plate cam provided rotatably by the third driving force generated by the second motor 338. The cam member 339a is provided to abut against the surface of the holding member 333c opposite to the surface supporting the first elastic member 333b. The rotation shaft 339b is the rotation shaft of the cam member 339a, and is attached to the second motor 338.

When the apparatus is started, the cam member 339a of the pressing force adjusting member 339 is arranged at an initial position illustrated in FIGS. 15A and 15B, and the first pressing member 333 is arranged at the first position. On the other hand, when the second motor 338 rotates and generates the third driving force, the cam member 339a rotationally moves to a moved position illustrated in FIGS. 16A and 16B, and the first pressing member 333 is arranged at the second position. Following the rotation of the cam member 339a, 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. Thus, 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 conveyance roller 116 increases.

Note that the pressing force adjusting member 339 may be provided to be rotatably moved manually by an operator instead of using the third driving force from the second motor 338 to adjust the pressing force by the first pressing member 333. As described above, the force directed outward in the width direction A2 applied to the medium being conveyed varies for each device. The medium conveying apparatus includes the pressing force adjusting member 339 that adjusts the pressing force by the first pressing member 333, such that the magnitude of the force directed outward in the width direction A2 applied to the medium being conveyed may be adjusted for each device individually.

In particular, the pressing force adjusting member 339 has a simpler structure than the angle adjusting member 239. Therefore, in the medium conveying apparatus, it is possible to adjust the force directed outward in the width direction A2 applied to the medium being conveyed for each device individually, while suppressing an increase in device cost.

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

In step S205, the press control unit 163 controls the second motor 338 to adjust the pressing force with which the first pressing member 333 presses the first driven roller 117 toward the first conveyance roller 116 based on the detected thickness of the medium and rotates the cam member 339a. For example, if the thickness of the medium is greater than the thickness threshold value, the press control unit 163 does not rotationally move the cam member 339a from the initial position and arranges the first pressing member 333 at the first position. On the other hand, if the thickness of the medium is equal to or less than the thickness threshold value, the press control unit 163 rotationally moves the cam member 339a from the initial position to the moved position, and arranges the first pressing member 333 at the second position.

The press control unit 163 may adjust the position of the cam member 339a in multiple stages including three or more stages such that the pressing force by the first pressing member 333 increases with thickness of the medium decrease (when the medium is thinner). Thus, the press control unit 163 more finely adjusts the magnitude of the force directed outward in the width direction A2 for each medium, and more appropriately suppresses the occurrence of wrinkles in the medium.

As described above, the pressing force adjusting member 339 adjusts the pressing force with which the first pressing member 333 presses the first driven roller 117 toward the first conveyance roller 116, based on the thickness of the medium determined by the determination unit 162. Therefore, the medium conveying apparatus appropriately conveys a PPC sheet and the like, which is less likely to wrinkle, by conveying in accordance with an initial setting of the apparatus, and thin papers, which are more likely to wrinkle, by strongly pulling toward the outside in the width direction A2 to suppress the occurrence of wrinkles in the thin paper.

Note that, regardless of the thickness of the medium, the press control unit 163 may adjust the pressing force by the pressing force adjusting member 339, if the user uses the operation device 105 or the information processing device to instruct an adjustment of the pressing force by the pressing force adjusting member 339.

The control unit 161 may also determine whether the medium of the input image has wrinkles, and when determining that the medium of the input image has wrinkles, the control unit 161 may correct the input image to remove the wrinkles, or may notify the user of a proposal to adjust the pressing force.

As described in detail above, the medium conveying apparatus conveys the medium in an excellent manner, even when adjusting the pressing force by the first pressing member 333 based on the thickness of the medium being conveyed.

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

As illustrated in FIG. 17, the support members 437 are used instead of the support members 137, and are provided to support the second shaft 132 outside from the two second driven rollers 120, that is, at the end portions of the width direction A2 perpendicular to the medium conveyance direction. A circular hole portion is formed in each of the support members 437, and end portions of the second shaft 132 in the width direction A2 are inserted into the hole portions, such that the support members 437 rotatably support the second shaft 132. Thus, the second shaft 132 is provided rotatably. The second driven rollers 120 are fixed to the second shaft 132 to rotate according to the rotation of the second shaft 132.

Note that, also in a case where the support members 437 are used instead of the support members 137, the first pressing member 233 and the angle adjusting member 239, or the first pressing member 333 and the pressing force adjusting member 339 may be used instead of the first pressing member 133.

As described in detail above, the medium conveying apparatus conveys the medium in an excellent manner, even when the second shaft 132 is provided rotatably.

FIGS. 18 and 19 are schematic views for explaining a conveyance mechanism 530 of a medium conveying apparatus according to still another embodiment. FIG. 18 is a schematic view of the conveyance mechanism 530 viewed from above. FIG. 19 is a schematic view of the conveyance mechanism 530 viewed from the side.

The medium conveying apparatus according to the present embodiment includes each component included in the medium conveying apparatus 100. However, as illustrated in FIGS. 18 and 19, the medium conveying apparatus includes the conveyance mechanism 530 instead of the conveyance mechanism 130. The conveyance mechanism 530 has a configuration similar to that of the conveyance mechanism 130. However, the conveyance mechanism 530 includes 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 a configuration similar to that of the second shaft 132. However, the second shaft 532 is inclined such that a center portion of the second shaft 532 in the width direction A2 perpendicular to the medium conveyance direction is arranged downstream from end portions of the second shaft 532 in the medium conveyance direction A1. In particular, the second shaft 532 is inclined in a bent (curved) manner. The first driven rollers 117 are provided on the second shaft 532 to be rotatable along a direction perpendicular to the direction in which the second shaft 532 extends. The second shaft 532 is provided non-rotatably, and the first driven rollers 117 are provided rotatably with respect to the second shaft 532. The second shaft 532 is arranged upstream of the first shaft 131, and the first driven rollers 117 are arranged upstream of the first conveyance rollers 116.

The first pressing member 533 is arranged to abut against the second shaft 532 between the two first driven rollers 117, that is, at a center portion in the width direction A2 perpendicular to the medium conveyance direction. The first pressing member 533 is provided to abut against the lower side of the second shaft 532 to press the second shaft 532 toward the first shaft 131, that is, to press the second shaft 532 upward. The first pressing member 533 includes a first abutment surface 533a and a first elastic member 533b.

The first abutment surface 533a abuts against the second shaft 532 and presses the second shaft 532. The first abutment surface 533a is formed to be parallel to the medium conveyance surface. The first elastic member 533b has a configuration similar to that of the first elastic member 133b, and is provided such that one end thereof is supported by the lower housing 101 and the other end abuts against the first pressing member 533. The first elastic member 533b applies a pressing force to the first abutment surface 533a from below to above along the height direction A3.

Also in this case, each of the first driven rollers 117 having the second shaft 532 as rotation shaft rotates to convey the medium outward in the width direction A2, and the medium is conveyed 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 rotation shaft of the first conveyance rollers 116, is provided to extend linearly in a straight manner. Thus, the medium conveying apparatus secures the medium conveyance force by the first conveyance rollers 116 and appropriately conveys the medium.

The second shaft 532 is bent in advance, such that the first abutment surface 533a of the first pressing member 533 may not be inclined. Thus, the medium conveying apparatus may use common components for the first pressing member 533 and the second pressing member 136, and it is possible to reduce the cost of the device.

Note that, also when the second shaft 532 is used instead of the second shaft 132, the first pressing member 333 and the pressing force adjusting member 339 may be used instead of the first pressing member 133. Further, the support members 437 may be used instead of the support members 137, the second shaft 532 may be rotatably provided, and the first driven rollers 117 may be fixed to the second shaft 532 such that the first driven rollers 117 rotate according to the rotation of the second shaft 532.

As described in detail above, the medium conveying apparatus conveys the medium in an excellent manner, even when the second shaft 532 is inclined in a bent (curved) manner.

FIG. 20 is a schematic view for explaining a conveyance mechanism 630 of a medium conveying apparatus according to still another embodiment. FIG. 20 is a schematic view of the conveyance mechanism 630 viewed from above.

The medium conveying apparatus according to the present embodiment includes each component included in the medium conveying apparatus 100. However, as illustrated in FIG. 20, the medium conveying apparatus includes the conveyance mechanism 630 instead of the conveyance mechanism 130. The conveyance mechanism 630 has a configuration similar to that of the conveyance mechanism 530. However, the conveyance mechanism 630 includes 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 to be bent.

Also in this case, each of the first driven rollers 117 having the second shaft 632 as rotation shaft rotates to convey the medium outward in the width direction A2, and the medium is conveyed 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 rotation shaft of the first conveyance rollers 116, is provided to extend linearly in a straight manner. Thus, the medium conveying apparatus secures the medium conveyance force by the first conveyance rollers 116 and appropriately conveys the medium.

The second shaft 632 is bent in advance, and thus, the first abutment surface 533a of the first pressing member 533 may not be inclined. Therefore, the medium conveying apparatus may use common components for the first pressing member 533 and the second pressing member 136, and it is possible to reduce the cost of the device.

Note that when the second shaft 632 is used instead of the second shaft 132, the first pressing member 333 and the pressing force adjusting member 339 may be used instead of the first pressing member 133. Further, the support members 437 may be used instead of the support members 137, the second shaft 632 may be rotatably provided, and the first driven rollers 117 may be fixed to the second shaft 632 such that the first driven rollers 117 rotate according to the rotation of the second shaft 632.

As described in detail above, the medium conveying apparatus conveys the medium in an excellent manner, even when the second shaft 532 is inclined to be bent.

FIGS. 21 and 22 are schematic views for explaining a conveyance mechanism 730 of a medium conveying apparatus according to still another embodiment. FIG. 21 is a schematic view of the conveyance mechanism 730 viewed from above. FIG. 22 is a schematic view of the conveyance mechanism 730 viewed from the side.

The medium conveying apparatus according to the present embodiment includes each component included in the medium conveying apparatus 100. However, as illustrated in FIGS. 21 and 22, the medium conveying apparatus includes the conveyance mechanism 730 instead of the conveyance mechanism 130. The conveyance mechanism 730 includes first conveyance rollers 716, first driven rollers 717, second conveyance rollers 719, second driven rollers 720, a first shaft 731, a second shaft 732, a first pressing member 733, a third shaft 734, a fourth shaft 735, a second pressing member 736, and the like.

The first conveyance rollers 716, the first driven rollers 717, the second conveyance rollers 719, the second driven rollers 720, the first shaft 731, the second shaft 732, the first pressing member 733, the third shaft 734, the fourth shaft 735, and the second pressing member 736 respectively have a configuration similar to the first conveyance rollers 116, the first driven rollers 117, the second conveyance rollers 119, the second driven rollers 120, the first shaft 131, the second shaft 132, the first pressing member 133, the third shaft 134, the fourth shaft 135, and the second pressing member 136.

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

The second shaft 732 is provided to extend linearly in a straight manner in the width direction A2. The first pressing member 733 is an example of a second presser, and is provided to abut against the upper side of the second shaft 732 to press the second shaft 732 toward the first shaft 731, that is, to press the second shaft 732 downward. The first pressing member 733 includes a first abutment surface 733a and a first elastic member 733b. The first abutment surface 733a is formed to be parallel to the medium conveyance surface. The first elastic member 733b has a configuration similar to that of the first elastic member 133b, and is provided such that one end thereof is supported by the upper housing 102 and the other end abuts against a rear surface side of the first pressing member 733. The first elastic member 733b applies a pressing force to the first abutment surface 733a from above to below along the height direction A3.

The fourth shaft 735 is provided to extend substantially in parallel to the width direction A2. The second pressing member 736 is an example of a presser, and is provided to abut against the upper side of the fourth shaft 735 to press the fourth shaft 735 toward the third shaft 734, that is, to press the fourth shaft 735 downward. The second pressing member 736 includes a second abutment surface 736a and a second elastic member 736b. The second abutment surface 736a is an example of an inclined surface, and is formed inclined with respect to the medium conveyance surface, in particular, inclined upward toward the downstream side. Thus, the second pressing member 736 is provided to press, when the second pressing member 736 presses the second shaft 732 from above along the height direction A3, a center portion of the second shaft 732 in the width direction A2 perpendicular to the medium conveyance direction toward the downstream side in the medium conveyance direction A1. The second elastic member 736b has a configuration similar to that of the second elastic member 136b, and is provided such that one end thereof is supported by the upper housing 102 and the other end abuts against the second pressing member 736. The second elastic member 736b applies a pressing force to the second abutment surface 736a from above to below along the height direction A3 perpendicular to the medium conveyance surface.

Thus, the fourth shaft 735 is bent 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. Accordingly, each of the second driven rollers 720 having the fourth shaft 735 as rotation shaft rotates to convey the medium outward in the width direction A2, and the medium is conveyed to be pulled outward. Therefore, the occurrence of wrinkles in the medium is suppressed.

In particular, the second drive rollers 720 provided above the second conveyance rollers 719 are arranged upstream of the second conveyance rollers 719, and the second abutment surface 736a of the second pressing member 736 presses downward the center portion of the fourth shaft 735 in the width direction A2. If the second pressing member 736 would not press the center portion of the fourth shaft 735 in the width direction A2 toward the downstream side, the fourth shaft 735 would be bent such that the center portion of the fourth shaft 735 in the width direction A2 is arranged on the upstream side to release the pressing force by the second elastic member 736b. Thus, each of the second driven rollers 720 having the fourth shaft 735 as rotation shaft rotates to convey the medium inward in the width direction A2, and the medium is conveyed to be pressed inward. Therefore, wrinkles are more likely to occur in the medium. In the medium conveying apparatus, the second pressing member 736 presses the center portion of the fourth shaft 735 in the width direction A2 toward the downstream side, and thus, it is possible to suppress the occurrence of wrinkles in the medium in an excellent manner.

The first driven rollers 717 provided above the first conveyance rollers 716 are arranged downstream of the first conveyance rollers 716, and the first abutment surface 733a of the first pressing member 733 presses downward the center portion of the second shaft 732 in the width direction A2. Therefore, the second shaft 732 is bent such that the center portion in the width direction A2 is arranged on the downstream side to release the pressing force by the first elastic member 733b. Thus, the second shaft 732 is bent 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. Accordingly, each of the first driven rollers 717 having the second shaft 732 as rotation shaft rotates to convey the medium outward in the width direction A2, and the medium is conveyed to be pulled outward. Therefore, the occurrence of wrinkles in the medium is suppressed.

As described above, the first abutment surface 733a of the first pressing member 733 is formed to be parallel to the medium conveyance surface. Therefore, the first pressing member 733 presses the center portion of the second shaft 732 in the width direction A2 perpendicular to the medium conveyance direction downward along the height direction A3, that is, toward the first shaft 731. Thus, the first pressing member 133 prevents the second shaft 132 from curving too much such that the center portion in the width direction A2 is arranged on the downstream side, and suppresses damage to the medium when a force directed outward is excessively applied to the medium.

The first shaft 731, which is the rotation shaft of the first conveyance rollers 716, and the third shaft 734, which is the rotation shaft of the second conveyance rollers 719, are provided to extend linearly in a straight manner. Thus, the medium conveying apparatus secures the medium conveyance force by the first conveyance rollers 716 and the second conveyance rollers 719 and appropriately conveys the medium.

Note that, even when the conveyance mechanism 730 is used instead of the conveyance mechanism 130, the angle adjusting member 239 may be used, and the second pressing member 736 may be rotatably provided, similarly to the first pressing member 233. The pressing force adjusting member 339 may be used, and the second pressing member 736 may be provided to adjust the pressing force, similarly to the first pressing member 333. Further, the support members 437 may be used instead of the support members 137, the fourth shaft 735 may be rotatably provided, and the second driven rollers 720 may be fixed to the fourth shaft 735 such that the second driven rollers 720 rotate according to the rotation of the fourth shaft 735. The fourth shaft 735 may be inclined to be bent similarly to the second shaft 532, and the second abutment surface 736a of the second pressing member 736 may be provided to not be inclined, similarly to the second abutment surface 136a of the second pressing member 136. Moreover, the fourth shaft 735 may be inclined to be bent similarly to the second shaft 632, and the second abutment surface 736a of the second pressing member 736 may be provided to not be inclined, similarly to the second abutment surface 136a of the second pressing member 136.

As described in detail above, the medium conveying apparatus conveys the medium in an excellent manner, even when the second driven rollers 720 are provided in the upper housing 102.

In particular, the medium conveying apparatus 100 suppresses the occurrence of wrinkles in the medium in the vicinity of the second conveyance rollers 719 and the second driven rollers 720.

FIG. 23 is a diagram illustrating a general configuration of a processing circuit 860 in a medium conveying apparatus according to still another embodiment. The processing circuit 860 is used instead of the processing circuit 160 of the medium conveying apparatus 100 and executes a medium reading process and the like in place of the processing circuit 160. The processing circuit 860 includes a control circuit 861, a determination circuit 862, a press control circuit 863, and the like. Note that each of these components may be formed by an independent integrated circuit, a microprocessor, firmware, or the like.

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

The determination circuit 862 is an example of a determination unit and has a function similar to the determination unit 162. The determination circuit 862 receives the ultrasonic signal from the ultrasonic sensor 114, determines the thickness of the medium, based on the received ultrasonic signal, and outputs a determination result to the press control circuit 863.

The press control circuit 863 is an example of a press control unit, and has a function similar to the press control unit 163. The press control circuit 863 receives the determination result of the thickness of the medium from the determination circuit 862, and controls the second motor 238 or the second motor 338, based on the thickness of the medium.

As described in detail above, the medium conveying apparatus conveys the medium in an excellent manner, even when the processing circuit 860 is used.

Although preferred embodiments have been described above, the embodiments are not limited thereto. For example, the medium conveying apparatus may be a printer that conveys a printing object or the like as a medium. In this case, the medium conveying apparatus includes a printing device instead of the imaging device 118. The printing device is placed at a position where the imaging device 118 is arranged. The medium conveying apparatus suppresses the occurrence of wrinkles in the medium (the printing object) being conveyed, and thus, it is possible to perform printing on the printing object in an excellent manner.

The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of the present invention. Any one of the above-described operations may be performed in various other ways, for example, in an order different from the one described above.

The functionality of the elements disclosed herein may be implemented using circuitry or processing circuitry which includes general purpose processors, special purpose processors, integrated circuits, application specific integrated circuits (ASICs), digital signal processors (DSPs), field programmable gate arrays (FPGAs), conventional circuitry and/or combinations thereof which are configured or programmed to perform the disclosed functionality. Processors are considered processing circuitry or circuitry as they include transistors and other circuitry therein. In the disclosure, the circuitry, units, or means are hardware that carry out or are programmed to perform the recited functionality. The hardware may be any hardware disclosed herein or otherwise known which is programmed or configured to carry out the recited functionality. When the hardware is a processor which may be considered a type of circuitry, the circuitry, means, or units are a combination of hardware and software, the software being used to configure the hardware and/or processor.

Claims

1. A medium conveying apparatus, comprising: a motor to generate a driving force;a first shaft extending linearly in a direction perpendicular to a medium conveyance direction to be rotated by the driving force;a conveyance roller fixed to the first shaft to convey a medium;a second shaft;a driven roller mounted on the second shaft to rotate following the conveyance roller; anda presser to press a center portion of the second shaft in a direction perpendicular to the medium conveyance direction to a downstream side in the medium conveyance direction.

2. The medium conveying apparatus according to claim 1, wherein the second shaft is non-rotatable, and the driven roller is mounted to be rotatable with respect to the second shaft.

3. The medium conveying apparatus according to claim 1, wherein the second shaft is rotatable, and the driven roller is fixed to the second shaft to rotate according to a rotation of the second shaft.

4. The medium conveying apparatus according to claim 1, wherein the second shaft is disposed upstream from the first shaft in the medium conveyance direction, andthe presser presses the center portion of the second shaft in the direction perpendicular to the medium conveyance direction to the downstream side in the medium conveyance direction and toward the first shaft.

5. The medium conveying apparatus according to claim 4, further comprising: a third shaft extending linearly in a direction perpendicular to the medium conveyance direction to be rotated by the driving force;a second conveyance roller fixed to the third shaft to convey a medium;a fourth shaft disposed downstream from the third shaft in the medium conveyance direction;a second driven roller mounted on the fourth shaft to rotate following the second conveyance roller; andanother presser to press a center portion of the fourth shaft in a direction perpendicular to the medium conveyance direction toward the third shaft in a direction perpendicular to a medium conveyance surface.

6. The medium conveying apparatus according to claim 1, further comprising an angle adjuster, wherein the presser has an inclined surface abutting against the second shaft, and the angle adjuster adjusts an inclination angle of the inclined surface.

7. The medium conveying apparatus according to claim 6, further comprising: processing circuitry configured to determine a thickness of the medium conveyed,wherein the angle adjuster adjusts the inclination angle of the inclined surface based on the thickness determined by the processing circuitry.

8. The medium conveying apparatus according to claim 1, further comprising: a pressing force adjuster to adjust a pressing force with which the presser presses the driven roller toward the conveyance roller.

9. The medium conveying apparatus according to claim 8, further comprising: processing circuitry to determine a thickness of the medium conveyed,wherein the pressing force adjuster adjusts the pressing force based on the thickness determined by the processing circuitry.

10. A medium conveying apparatus, comprising: a motor to generate a driving force;a first shaft extending linearly in a direction perpendicular to a medium conveyance direction to be rotated by the driving force;a conveyance roller fixed to the first shaft to convey a medium;a second shaft inclined such that a center portion of the second shaft in a direction perpendicular to the medium conveyance direction is located downstream from end portions of the second shaft in the medium conveyance direction; anda driven roller mounted on the second shaft to rotate following the conveyance roller.