JP2017030921A - Sheet conveying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet conveying apparatus capable of suppressing reduction in separation performance when an excessive number of sheets are loaded on a loading surface.SOLUTION: An image reading apparatus comprises a loading surface 150A, a feed roller 41, a separation roller 42, a holder 30, an opposing wall part 51, and a regulation part 100. Sheets SH are loaded on the loading surface 150A. The feed roller 41 feeds the sheets SH loaded on the loading surface 150A in a conveying direction. The separation roller 42 conveys the conveyed sheets SH while separating them one by one. The holder 30 supports the feed roller 41 rotatably. The opposing wall part 51 opposes the loading surface 150 while positioning the holder 30 therebetween. When the holder 30 swings in a direction of approaching the opposing wall part 51 and the feed roller 41 separates from the loading surface 150A, the regulation part 100 specifies a maximum separation position L1 where an outer peripheral surface 41A of the feed roller 41 is separated most from the loading surface 150A, and regulates the swing of the holder 30.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a sheet conveying apparatus.

  Patent Document 1 discloses an example of a conventional sheet conveying apparatus. The sheet conveying apparatus includes a stacking surface, a pickup roller, a separation roller, a holder, and a cover.

  The stacking surface is formed by the upper surfaces of the paper feed tray and the paper feed slope. Sheets are stacked on the stacking surface. The pickup roller sends out the sheets stacked on the stacking surface in the transport direction. The separation roller is located downstream of the pickup roller in the transport direction. The separation roller is driven to rotate by a separation roller shaft extending in the width direction orthogonal to the conveyance direction on the stacking surface. The separation roller conveys the sheet conveyed by the pickup roller in the conveyance direction while separating the sheets one by one. The holder is supported so as to be swingable around the separation roller shaft. The holder supports the pickup roller rotatably. The cover faces the loading surface with the holder positioned therebetween.

  In this sheet conveying apparatus, before the sheet is conveyed, the separation roller shaft rotates, and the holder swings in a direction approaching the cover with the separation roller shaft as a center (hereinafter, the holder is described as being raised). Thereby, the pickup roller supported by the holder is lifted, and a gap is formed between the stacking surface and the outer peripheral surface of the pickup roller. By inserting a plurality of sheets in the gap, the plurality of sheets can be placed together on the stacking surface.

Japanese Patent No. 4051832

  However, it is considered that the number of sheets that can be stacked together on the stacking surface, that is, the limit number of sheets that can be separated with high accuracy, increases or decreases according to the separation performance of the separation roller or the like. On the other hand, in the above-described sheet conveying apparatus, the mechanism for swinging the holder in the direction approaching the cover includes, for example, a protrusion provided on the holder and a leaf spring. Therefore, in the position where the holder is raised by the protrusion and the leaf spring, when a force that further lifts the holder in the direction approaching the cover is applied, the holder can be further raised by deformation of the leaf spring. Therefore, in the conventional sheet conveying apparatus, it is conceivable that the user easily inserts an excessive number of sheets into the gap between the stacking surface and the outer peripheral surface of the pickup roller. In that case, it becomes difficult for the separation roller or the like to sufficiently exhibit the original separation performance, and as a result, in this sheet conveying apparatus, there is a possibility that double feeding or idle feeding or the like occurs.

  The present invention has been made in view of the above-described conventional situation, and an object of the present invention is to provide a sheet conveying apparatus that can suppress an excessive number of sheets from being stacked on a stacking surface and reducing separation performance. .

The sheet conveying apparatus of the present invention includes a stacking surface on which sheets are stacked,
A supply roller for feeding out the sheets stacked on the stacking surface in the transport direction;
Sheets conveyed by the supply roller one by one, which are positioned downstream of the supply roller in the conveyance direction and rotate about a rotation axis extending in the width direction perpendicular to the conveyance direction on the stacking surface. Separating rollers that are transported in the transport direction while being separated into
A holder that is swingably supported around the rotation axis, and that rotatably supports the supply roller;
An opposing wall facing the stacking surface with the holder in between,
When the holder is swung in a direction approaching the facing wall and the supply roller is separated from the stacking surface, the maximum separation position where the outer peripheral surface of the supply roller is most separated from the stacking surface is defined. And a restricting portion for restricting swinging of the holder.

  In the sheet conveying apparatus of the present invention, the regulating portion swings in the direction in which the holder approaches the opposing wall portion, and when the supply roller is separated from the stacking surface, the outer peripheral surface of the supply roller is most separated from the stacking surface. Defines the maximum separation position and regulates swinging of the holder. For this reason, it is possible to prevent the user from stacking an excessive number of sheets on the stacking surface. As a result, in the sheet conveying apparatus of the present invention, it is possible to prevent the separation roller or the like from fully exhibiting the original separation performance and the occurrence of double feeding or idle feeding.

  Therefore, in the sheet conveying apparatus of the present invention, it is possible to suppress the separation performance from being deteriorated due to an excessive number of sheets stacked on the stacking surface.

1 is a perspective view of an image reading apparatus according to Embodiment 1. FIG. 1 is a schematic front view of an image reading apparatus according to Embodiment 1. FIG. 1 is a schematic partial cross-sectional view of an image reading apparatus according to Embodiment 1. FIG. FIG. 3 is a partial perspective view illustrating a state in which the open / close cover is removed according to the image reading apparatus of Embodiment 1. FIG. 3 is a partial cross-sectional view mainly illustrating a stacking surface, a supply roller, a separation roller, a holder, and a regulating unit according to the image reading apparatus of Embodiment 1. FIG. 6 is a partial cross-sectional view illustrating a state in which the swing of the holder is restricted by a restriction portion at a maximum separation position in the image reading apparatus according to the first exemplary embodiment. FIG. 6 is a partial cross-sectional view mainly showing a stacking surface, a supply roller, a separation roller, and a holder according to an image reading apparatus of a reference example. FIG. 9 is a partial cross-sectional view mainly illustrating a stacking surface, a supply roller, a separation roller, a holder, and a regulating unit in the image reading apparatus according to the second embodiment. FIG. 10 is a partial perspective view illustrating a restriction unit in the image reading apparatus according to the second exemplary embodiment. FIG. 10 is a partial cross-sectional view illustrating a state in which the swing of the holder is restricted by a restricting portion at a maximum separation position in the image reading apparatus according to the second embodiment. FIG. 10 is a schematic top view illustrating a supply roller, a separation roller, a holder, a rotation shaft of the supply roller, and a fifth convex portion of a restriction portion in the image reading apparatus of Example 3. FIG. 11 is a cross-sectional view of the image reading apparatus according to the third embodiment, taken along the line AA in FIG. It is sectional drawing. FIG. 10 is a partial cross-sectional view illustrating a state in which the swing of the holder is restricted by a restriction portion at a maximum separation position in the image reading apparatus according to the third embodiment.

  Embodiments 1 to 3 embodying the present invention will be described below with reference to the drawings.

Example 1
As shown in FIG. 1, the image reading apparatus 1 according to the first exemplary embodiment is an example of a specific aspect of the sheet conveying apparatus of the present invention. In FIG. 1, the side on which the operation panel 8P is arranged is defined as the front of the apparatus, and the side that comes to the left hand when facing the operation panel 8P is defined as the left side. To do. 2 are displayed in correspondence with the directions shown in FIG. 1. Hereinafter, each component provided in the image reading apparatus 1 will be described with reference to FIG.

<Overall configuration>
As shown in FIGS. 1 to 3, the image reading apparatus 1 includes a main body unit 8, an opening / closing unit 9, an image forming unit 5, a reading unit 3, and a conveying unit 4. The main body 8 is a flat substantially box-shaped body. As shown in FIG. 1, an operation panel 8 </ b> P that is a touch panel or the like is provided on the front surface of the main body 8.

  As shown in FIG. 2, the image forming unit 5 is accommodated in a lower portion in the main body 8. The image forming unit 5 forms an image on the sheet SH by an ink jet method or a laser method. As shown in FIGS. 2 and 3, the reading unit 3 is accommodated in the upper part in the main body 8. The reading unit 3 is used when reading an image of a document. The transport unit 4 is provided in the opening / closing unit 9. The transport unit 4 is used when causing the reading unit 3 to read an image of the sheet SH while sequentially transporting the sheets SH placed on the supply tray 91 along the transport path P1.

  As shown in FIG. 3, a first platen glass 81 and a second platen glass 82 are disposed on the upper surface of the main body 8. A document support surface 81 </ b> A is formed by the upper surface of the first platen glass 81. The document support surface 81A supports the document from below when the reading unit 3 reads an image of the stationary document. Documents to be read include books, in addition to sheets such as paper and OHP sheets.

  The second platen glass 82 is located on the left side of the first platen glass 81 and extends in the longitudinal direction. A reading surface 82 </ b> A is formed by the upper surface of the second platen glass 82. The reading surface 82A guides the conveyed sheet SH from below when the reading unit 3 reads an image of the sheet SH conveyed one by one by the conveying unit 4. In this embodiment, an object whose image is read using the document support surface 81A is referred to as a document, and an object whose image is read while being conveyed by the conveying unit 4 is referred to as a sheet SH. The document and the sheet SH may be substantially the same.

  As shown in FIG. 1, the opening / closing part 9 is supported by a hinge (not shown) disposed at the rear part of the body part 8 so as to be swingable around an opening / closing axis X9 extending in the left-right direction. In the closed state shown in FIGS. 1 to 3, the opening / closing unit 9 covers the document support surface 81 </ b> A from above. Although not shown, the opening / closing portion 9 swings around the opening / closing axis X9 so that the front end portion thereof is displaced upward and backward, thereby exposing the document support surface 81A. As a result, the user can support the document to be read on the document support surface 81A.

  As shown in FIGS. 1 and 3, an opening / closing cover 50 is provided on the upper portion of the opening / closing part 9. The opening / closing cover 50 is a substantially flat plate member that extends in the front-rear and left-right directions from approximately the center of the opening / closing portion 9 to the left end. The left end of the opening / closing cover 50 is bent downward. The opening / closing cover 50 is supported by the opening / closing portion 9 at the left end and the lower end thereof so as to be swingable around an opening / closing axis X50 extending in the front-rear direction. Thereby, the open / close cover 50 can be displaced between a closed position indicated by a solid line in FIGS. 1 and 3 and an open position indicated by a two-dot chain line in FIG. 3. The closed position is an example of the “first position” of the open / close cover of the present invention, and the open position is an example of the “second position” of the open / close cover of the present invention.

  As shown in FIG. 3, a plurality of guide ribs 50 </ b> R extending in the left-right direction are formed on the inner surface of the opening / closing cover 50 side by side in the front-rear direction. An upper guide surface 50A is formed by the lower end edge of the guide rib 50R. 50 A of upper guide surfaces prescribe | regulate the upper path | route P1A mentioned later among the conveyance paths P1 from the top.

  The reading unit 3 includes a reading sensor 3S accommodated in an upper part in the main body 8 and a scanning mechanism (not shown). The reading sensor 3S is an example of the “reading unit” in the present invention. In the main body 8, the scanning mechanism reciprocates the reading sensor 3S in the left-right direction below the document support surface 81A and the reading surface 82A. When reading an image of a document supported on the document support surface 81A, the reading sensor 3S reads the image while moving below the document support surface 81A. The position at which the reading sensor 3S stops below the reading surface 82A is a predetermined stationary reading position. When an image is read while the sheet SH is conveyed by the conveyance unit 4, the reading sensor 3S is stopped at the stationary reading position. As the reading sensor 3S, a known image reading sensor such as a CIS (Contact Image Sensor) or a CCD (Charge Coupled Device) is used.

  As shown in FIGS. 1 to 3, the transport unit 4 includes a supply tray 91 and a discharge tray 92.

  The supply tray 91 is formed in the right part of the opening / closing part 9. The upper surface of the supply tray 91 is a support surface 91A that supports the sheet SH from below. On the support surface 91A, a plurality of sheets SH to be read conveyed by the conveyance unit 4 are stacked. The support surface 91A is a flat surface that inclines downward to the left.

  As shown in FIGS. 1, 3, and 4, the supply tray 91 is provided with two guides 60A and 60A that are slidable in the front-rear direction. The guides 60A and 60A face each other in the front-rear direction and are connected by a rack and pinion mechanism 60R shown in FIG. When the front guide 60A and the rear guide 60A approach or separate from each other, a plurality of types of sheets SH of different sizes supported by the supply tray 91 are sandwiched from the front and rear.

  As shown in FIGS. 1 to 3, the discharge tray 92 is located below the supply tray 91. The upper surface of the discharge tray 92 is a support surface 92A that supports the sheet SH from below. On the support surface 92A, an image is read by the reading sensor 3S, and the sheet SH discharged by the transport unit 4 is stacked. The support surface 92A is a flat surface that inclines upward from left to right.

  As shown in FIG. 3, the transport unit 4 is provided between the opening / closing cover 50 in the opening / closing unit 9 and the left portion of the base member 9 </ b> A. The base member 9 </ b> A constitutes the bottom of the opening / closing part 9. The right portion of the base member 9A constitutes a discharge tray 92. The transport unit 4 includes an upper chute member 130 and a lower chute member 140.

  The upper chute member 130 and the lower chute member 140 are assembled to the base member 9A. The lower chute member 140 is positioned below the upper chute member 130. The base member 9 </ b> A is located below the lower chute member 140.

  On the upper surface of the upper chute member 130, a first upper transport surface 130A and a second upper transport surface 130B are formed. The first upper transport surface 130 </ b> A is a flat surface that slopes downward to the left following the supply tray 91. The first upper conveying surface 130A of the upper chute member 130 and the support surface 91A of the supply tray 91 constitute a loading surface 150A. A plurality of sheets SH to be read that are transported by the transport unit 4 are stacked on the stacking surface 150A. The second upper transport surface 130B is a substantially flat surface that slopes up and to the left following the first upper transport surface 130A.

  Lower conveyance surfaces 140A1 and 140A2 are formed on the lower surface of the lower chute member 140. The lower conveyance surface 140A1 is a substantially flat surface inclined downward from the vicinity of the left end portion in the opening / closing unit 9 toward the reading surface 82A in the right direction. The lower transport surface 140A2 is a substantially flat surface that slopes up and to the right following the lower transport surface 140A1. On the upper surface of the base member 9A, a lower transport surface 50B1 that faces the lower transport surface 140A1 from below and a lower transport surface 50B2 that faces the lower transport surface 140A2 from below are formed.

  The transport unit 4 has a transport path P <b> 1 that connects the supply tray 91 and the discharge tray 92. The conveyance path P1 includes first and second upper conveyance surfaces 130A and 130B of the upper chute member 130, lower conveyance surfaces 140A1 and 140A2 of the lower chute member 140, an upper guide surface 50A of the opening / closing cover 50, and a lower conveyance surface 50B1 of the base member 9A. , 50B2, and a space surrounded by various conveying rollers. The conveyance path P1 includes an upper path P1A that is a portion extending leftward from the support surface 91A of the supply tray 91 along the first and second upper conveyance surfaces 130A and 130B of the upper chute member 130. Next, the conveyance path P1 includes a curved path P1B that is connected to the upper path P1A and is curved downward. Next, the conveyance path P1 is connected to the curved path P1B, and after being inclined downward toward the reading surface 82A from the lower end of the curved portion, the conveyance path P1 extends to the right along the reading surface 82A, and the reading surface 82A. It includes a lower path P1C composed of a portion that rises further to the right from the right end and reaches the discharge tray 92. The upper path P1A and the lower path P1C overlap in the vertical direction.

  The conveyance direction of the sheet SH conveyed by the conveyance unit 4 is leftward in the upper path P1A of the conveyance path P1, and is changed from the left direction to the right in the curved path P1B of the conveyance path P1, and the lower path of the conveyance path P1. In P1C, it faces right. The extending direction and shape of the transport path P1 are an example.

  As shown in FIGS. 3 and 4, the transport unit 4 includes a separation roller 42, a separation roller rotation shaft 42 </ b> S, a separation pad 43, a holder 30, a supply roller 41, and a supply roller rotation shaft 41 </ b> S.

  The separation roller 42 is located to the left of the supply roller 41, that is, downstream in the transport direction in the transport path P1. The separation roller 42 is provided at a position facing the second upper conveying surface 130B of the upper chute member 130 from above.

  The rotation shaft 42S is a cylindrical shaft body that extends around a rotation axis X42 that extends in the front-rear direction, which is a direction orthogonal to the conveyance direction of the sheet SH. The front end and the rear end of the rotation shaft 42S of the separation roller 42 are arranged inside a standing wall portion 90F that forms the front end portion of the opening / closing portion 9 and a standing wall portion 90R that forms the rear end portion of the opening / closing portion 9 ( (Not shown) are rotatably supported. The separation roller 42 is assembled at the center of the rotation shaft 42S.

  The separation pad 43 forms a conveyance surface of the sheet SH together with the second upper conveyance surface 130B. The separation pad 43 is provided at a position facing the separation roller 42 from below. The separation pad 43 is a plate-like body made of a soft material such as rubber or elastomer. The separation pad 43 is pressed toward the separation roller 42 by the biasing spring 43S.

  As shown in FIGS. 3 and 4, the holder 30 accommodates the separation roller 42 in a state of being sandwiched from the front and rear sides while covering the separation roller 42 from above. Details will be described later. The holder 30 is supported by the rotation shaft 42S so as to be swingable around the rotation axis X42 of the separation roller 42. Further, the holder 30 extends rightward with respect to the rotation shaft 42S, that is, upstream in the transport direction.

  As shown in FIG. 3, the supply roller 41 is provided at a position facing the first upper conveying surface 130 </ b> A of the upper chute member 130 from above. The supply roller 41 is provided so as to be able to contact the sheet SH stacked on the stacking surface 150A from above. The supply roller 41 is located on the right side with respect to the separation roller 42 and is accommodated in the holder 30. The supply roller 41 is supported by the holder 30 so as to be rotatable around a rotation axis X41 parallel to the rotation axis X42. Therefore, the holder 30 swings upward or downward around the rotation axis X42 of the separation roller 42 so that the supply roller 41 can be displaced between a position approaching the loading surface 150A and a position separating it. Has been.

  As shown in FIGS. 3 and 4, the holder 30 has an upper wall portion 31 that covers the supply roller 41 and the separation roller 42 from above. The upper wall portion 31 is formed with a protruding portion 32 that swells upward from a portion located between the rotation axis X41 and the rotation axis X42 at the rear end. The protruding portion 32 accommodates a transmission gear group (not shown) that transmits a driving force from the rotating shaft 42 </ b> S to the supply roller 41. The holder 30 is connected to the upper wall portion 31 and has a front wall portion 33 and a rear wall portion 35 that cover the supply roller 41 and the separation roller 42 from the front and rear. The front wall portion 33 and the rear wall portion 35 are extended downward in a direction orthogonal to the upper wall portion 31. The rotation shaft 42 </ b> S of the separation roller 42 passes through the front wall portion 33 and the rear wall portion 35 of the holder 30.

  When the rotary shaft 42S is rotated by being driven by a drive unit (not shown), the separation roller 42 and the supply roller 41 are rotated synchronously. The outer peripheral surface 41 </ b> A of the supply roller 41 imparts a conveying force to the uppermost sheet SH among the sheets SH stacked on the stacking surface 150 </ b> A, and sends the sheet SH toward the separation roller 42. The separation roller 42 cooperates with the separation pad 43 to separate the sheets SH conveyed by the supply roller 41 one by one, and conveys the sheet SH downstream in the conveyance direction on the conveyance path P1.

  The transport unit 4 includes a transport roller 44 and a pinch roller 44P in the upper path P1A of the transport path P1 on the left side of the separation roller 42, that is, at a position downstream of the separation roller 42 in the transport direction. Yes. The conveyance roller 44 and the pinch roller 44P nip the sheet SH separated one by one by the separation roller 42 and the separation pad 43, and convey the sheet SH toward the downstream in the conveyance direction.

  As shown in FIG. 3, the transport unit 4 includes a curved guide surface 45G, a curved guide surface 45H, a transport roller 45, and a pinch roller 45P in the curved path P1B of the transport path P1. The curved guide surface 45G and the curved guide surface 45H are opposed to each other with a predetermined interval. The curved guide surface 45G defines a portion that curves downward in the curved path P1B from the outside. The curved guide surface 45H defines a portion that curves downward in the curved path P1B from the inside. The conveyance roller 45 and the pinch roller 45P are disposed at the lower end of the curved path P1B. The conveyance roller 45 and the pinch roller 45P nip the sheet SH conveyed by the conveyance roller 44 and the pinch roller 44P and further convey the sheet SH toward the reading surface 82A. Between the conveyance roller 44 and the pinch roller 44P and the reading surface 82A, the lower conveyance surface 140A1 and the lower guide surface 50B1 face each other with a predetermined interval, thereby defining the left portion of the lower path P1C. .

  The transport unit 4 has a pressing member 49 at a position facing the reading surface 82A from above. A compression coil spring 49 </ b> S is disposed between the lower surface of the lower chute member 140 and the pressing member 49. The pressing member 49 is urged by the compression coil spring 49S and presses the sheet SH conveyed by the conveying roller 45 from above so as to contact the reading surface 82A.

  The transport unit 4 includes a discharge roller 48 and a pinch roller 48P on the right side of the pressing member 49 (reading surface 82A). The lower conveyance surface 140A2 and the lower guide surface 50B2 face each other with a predetermined distance between the pressing member 49 (reading surface 82A) and the discharge roller 48 and the pinch roller 48P, so that the right portion of the lower path P1C. Is stipulated.

  A path formed by the lower conveyance surface 140A2 and the lower guide surface 50B2 is inclined to the right of the pressing member 49 and toward the discharge roller 48 and the pinch roller 48P.

  The discharge roller 48 is located at the right end portion of the lower conveyance surface 140A2 of the lower chute member 140. The pinch roller 48P is located at the right end of the lower guide surface 50B2. The discharge roller 48 and the pinch roller 48P nip the sheet SH that has passed over the reading surface 82A and discharge it toward the support surface 92A of the discharge tray 92.

<Image reading operation>
In the image reading apparatus 1, when reading an image of a document supported on the document support surface 81A, a scanning mechanism (not shown) is operated in the reading unit 3, and the reading sensor 3S is positioned below the left edge of the document support surface 81A. It is moved in the left-right direction from the reading start position to the reading end position located below the right edge. As a result, the reading sensor 3S reads the image of the document supported on the document support surface 81A. Thereafter, a scanning mechanism (not shown) returns the reading sensor 3S that has finished reading to the standby position.

  Further, in the image reading apparatus 1, when reading an image of the sheet SH stacked on the stacking surface 150A, a scanning mechanism (not shown) operates in the reading unit 3, and the reading sensor 3S is moved to a stationary reading position below the reading surface 82A. To stop. When the transport unit 4 sequentially transports the sheets SH stacked on the stacking surface 150A along the transport path P1, the sheets SH are transported by the supply roller 41, the separation roller 42, etc., and come into contact with the reading surface 82A. However, it passes over the reading sensor 3S in the stationary reading position. The reading sensor 3S provided downstream of the separation roller 42 in the conveying direction reads the image of the sheet SH that passes through the reading sensor 3S. Then, the sheet SH from which the image has been read is discharged to the discharge tray 92 by the discharge roller 48 and the pinch roller 48P. The discharged sheet SH is supported from below by the support surface 92A of the discharge tray 92.

<Specific configuration of opposing wall and regulating portion>
As shown in FIGS. 3 and 4, the image reading apparatus 1 further includes an opposing wall portion 51 and a restriction portion 100.

  A part of the inner surface of the opening / closing cover 50 is an opposing wall 51. That is, the opposing wall portion 51 is a wall portion that is positioned above the holder 30 and extends substantially horizontally with the opening / closing cover 50 in the closed position. The facing wall 51 faces the stacking surface 150A with the holder 30 positioned therebetween.

  The facing wall 51 covers the holder 30, the supply roller 41, and the separation roller 42 from above in a state where the opening / closing cover 50 is in the closed position. Further, the facing wall 51 is separated from the stacking surface 150A and opens the holder 30, the supply roller 41, and the separation roller 42 in a state where the opening / closing cover 50 is in the open position. As a result, it is possible to easily perform the operation of removing the sheet jammed around the holder 30 and the like.

  As shown in FIGS. 3 to 6, the restricting portion 100 includes a holder rib 110 and a cover rib 120.

  The holder rib 110 is formed at the front portion of the outer peripheral surface of the protruding portion 32 of the holder 30 and protrudes toward the opposing wall portion 51. The holder rib 110 has a substantially rectangular shape. The upper surface of the holder rib 110 is a flat surface. The holder rib 110 is an example of the “first convex portion” in the present invention. In this embodiment, the holder 30 is a resin molded product manufactured by injection molding or the like, and the holder rib 110 is integrally formed with the holder 30.

  The cover rib 120 is formed at a substantially central portion in the left-right direction and the front-rear direction of the opposing wall portion 51, and protrudes toward the holder 30. The cover rib 120 has a substantially rectangular parallelepiped shape smaller than the holder rib 110. The lower surface of the cover rib 120 is a flat surface. The cover rib 120 extends vertically downward with the open / close cover 50 in the closed position. The cover rib 120 is an example of the “second convex portion” in the present invention. In this embodiment, the open / close cover 50 is a resin molded product manufactured by injection molding or the like, and the cover rib 120 is integrally formed with the open / close cover 50.

  As shown in FIG. 6, when the holder 30 swings in a direction approaching the facing wall portion 51, the upper surface of the holder rib 110 and the lower surface of the cover rib 120 approach each other. Further, when the holder 30 swings, the upper surface of the holder rib 110 and the lower surface of the cover rib 120 come into contact with each other, so that the swing of the holder 30 in the direction approaching the facing wall portion 51 is restricted. Thus, the maximum separation position L1 at which the outer peripheral surface 41A of the supply roller 41 is most separated from the first upper conveyance surface 130A is defined.

<Effect>
In the image reading apparatus 1 of the embodiment, the upper limit number of sheets SH stacked on the stacking unit 150A is as large as possible within a range in which the separation roller 42, the separation pad 43, and the like can sufficiently exhibit the original separation performance. Is set to The maximum separation position L1 between the lower end of the outer peripheral surface 41A of the supply roller 41 and the stacking surface 150 (first upper transport surface 130A) is set corresponding to the upper limit number of sheets SH. Specifically, the maximum separation position L1 is set to a value obtained by multiplying the standard sheet thickness by the upper limit number. In the example of FIG. 6, the upper limit number of sheets SH stacked on the stacking unit 150A is set to 50 sheets.

  As shown in FIGS. 5 and 6, the user stacks one or more sheets SH on the stacking unit 150 </ b> A, and inserts the leading edge of the sheet SH to below the supply roller 41. Then, since the supply roller 41 is pushed up by the leading edge of the sheet SH, the holder 30 swings upward around the rotation axis X42.

  For example, as shown in FIG. 5, when the number of stacked sheets SH stacked on the stacking unit 150 </ b> A is about 1 to several, the holder 30 slightly swings in the direction in which the holder rib 110 and the cover rib 120 approach each other. The outer peripheral surface 41A of the supply roller 41 is slightly separated from the first upper transport surface 130A. A distance between the outer peripheral surface 41A of the supply roller 41 and the first upper transport surface 130A is L2.

  As the number of stacked sheets SH stacked on the stacking unit 150A increases, the holder 30 further swings around the rotation axis X42, and the distance L2 increases.

  As shown in FIG. 6, when the number of stacked sheets SH stacked on the stacking unit 150 </ b> A is 50, which is the upper limit number, the holder rib 110 of the holder 30 is displaced upward and comes into contact with the cover rib 120. As a result, the swing of the holder 30 is restricted, and the distance L2 cannot exceed the maximum separation position L1. Thereby, it is possible to prevent the number of sheets SH exceeding the upper limit number of sheets from being stacked on the stacking surface 150A.

  As described above, in this image reading apparatus 1, even if the user attempts to stack a number of sheets SH exceeding the preset upper limit number on the stacking surface 150 </ b> A, the user places the excessive number of sheets SH below the supply roller 41. It is difficult to insert up to. For this reason, in this image reading apparatus 1, the separation roller 42, the separation pad 43, and the like sufficiently exhibit the original separation performance, and it is possible to suppress the occurrence of double feeding or idle feeding.

  Therefore, according to the image reading apparatus 1 of the first embodiment, it is possible to suppress a reduction in separation performance due to an excessive number of sheets SH being stacked on the stacking surface 150A.

  In the image reading apparatus 1, the upper limit of the separation distance between the outer peripheral surface 41 </ b> A of the supply roller 41 and the first upper transport surface 130 </ b> A can be reliably defined by the simple holder rib 110 and the cover rib 120.

  Furthermore, in this image reading apparatus 1, since the holder 30 and the opening / closing cover 50 are resin molded products manufactured by injection molding or the like, and the holder rib 110 and the cover rib 120 are integrally formed therewith, the manufacturing cost can be reduced. realizable. In addition, when the holder rib 110 is formed on the holder 30, holder ribs 110 having different shapes and heights can be easily formed by selectively attaching a plurality of shapes of inserts to a mold for injection molding the holder 30. It is. The same applies when the cover rib 120 is formed on the opening / closing cover 50.

  As shown in the reference example in FIG. 7, for example, for the image reading apparatus 1, an upper limit number exceeding 50 sheets may be set for different grades even in the same model. In the reference example of FIG. 7, the upper limit number of sheets SH stacked on the stacking unit 150A is set to 100 sheets. In this case, with respect to the image reading apparatus 1, it is possible to cope with an increase in the upper limit number of sheets by removing the holder rib 110 and the cover rib 120 by exchanging the insert attached to the mold for injection molding the holder 30 and the opening / closing cover 50.

  For example, as shown in FIG. 7, when the number of stacked sheets SH stacked on the stacking unit 150A is 100, which is the upper limit number, the uppermost sheet SH includes the first upper transport surface 130A and the open / close cover 50. The height of the guide rib 50R formed at the right end of the sheet is in contact with the lower edge of the guide rib 50R. At this time, since the swing of the holder 30 is not restricted, the holder 30 is displaced further upward than in the case of FIG. As a result, the separation distance L2 between the outer peripheral surface 41A of the supply roller 41 and the first upper conveyance surface 130A exceeds the maximum separation distance L1, and can accommodate up to 100 sheets, which is the upper limit number. In addition, the protrusion part 32 of the holder 30 and the opposing wall part 51 of the opening / closing cover 50 are in direct contact with each other, thereby restricting the swing of the holder 30 and forming the maximum separation position L1 corresponding to the upper limit of 100 sheets SH. You may comprise.

(Example 2)
As illustrated in FIGS. 8 to 10, the image reading apparatus according to the second embodiment employs a restriction unit 200 instead of the restriction unit 100 according to the image reading apparatus 1 according to the first embodiment. The restricting portion 200 includes a holder rib 210 and a cover rib 220. The holder rib 210 is an example of the “third convex portion” in the present invention, and the cover rib 220 is an example of the “fourth convex portion” in the present invention.

  The holder rib 210 is formed on the outer peripheral surface of the upper wall portion 31 of the holder 30, and protrudes leftward from the upper wall portion 31, that is, toward the downstream in the transport direction. The holder rib 210 has a substantially prismatic shape. As shown in FIG. 8, the holder rib 210 extends horizontally in the left direction with the holder 30 in contact with the first upper transport surface 130 </ b> A of the stacking surface 150 </ b> A or slightly spaced upward.

  As shown in FIGS. 8 to 10, the cover rib 220 is formed at a substantially central portion in the left-right direction and the front-rear direction of the facing wall 51 of the opening / closing cover 50, and protrudes downward from the facing wall 51 toward the holder rib 210. Yes. The cover rib 220 has a substantially rectangular parallelepiped shape larger than the holder rib 210. An opening 221 is formed in the lower part of the cover rib 220. The opening 221 is a substantially rectangular hole that penetrates the cover rib 220 in the left-right direction. As shown in FIG. 9, the end portion 211 of the holder rib 210 is inserted through the opening 221.

  Other configurations of the second embodiment are the same as those of the first embodiment. For this reason, about the same structure as Example 1, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified.

  As shown in FIG. 10, when the holder 30 swings in a direction approaching the facing wall portion 51, the tip end portion 211 of the holder rib 210 of the restricting portion 200 is displaced downward. When the holder 30 further swings, the tip end portion 211 comes into contact with the inner peripheral edge 221 </ b> A of the opening 221. As a result, the swing of the holder 30 is restricted, and the maximum separation position L1 is defined. The maximum separation position L1 is set in the same manner as in the first embodiment.

  Similarly to the image reading apparatus 1 of the first embodiment, the image reading apparatus of the second embodiment having the above configuration can suppress an excessive number of sheets SH from being stacked on the stacking surface 150A and degrading the separation performance.

(Example 3)
As illustrated in FIGS. 11 to 13, the image reading apparatus according to the third embodiment employs a restriction unit 300 instead of the restriction unit 100 according to the image reading apparatus 1 according to the first embodiment. The restriction part 300 includes a cover rib 320. The cover rib 320 is an example of the “fifth convex portion” in the present invention.

  As shown in FIG. 11, an insertion hole 31 </ b> H is provided through the upper wall portion 31 of the holder 30 in the vertical direction. The insertion hole 31 </ b> H is formed in a portion of the upper wall portion 31 of the holder 30 that is further forward than the front end of the supply roller 41 and overlaps the rotation shaft 41 </ b> S of the supply roller 41 in the vertical direction. The insertion hole 31H is a rectangular hole that is long in the left-right direction. As shown in FIG. 11, when the holder 30 is viewed from above, the insertion hole 31H and the rotation shaft 41S appear to overlap each other.

  The cover rib 320 is formed in the left-right direction of the opposing wall part 51 of the opening-and-closing cover 50, and the approximate center part of the front-back direction, and protrudes downward so as to pass through the insertion hole 31H of the holder 30. As shown in FIGS. 11 and 12, the lower end portion of the cover rib 320 extends from the front to a position facing the front end portion of the supply roller 41. The cover rib 320 is a substantially rectangular parallelepiped having a tapered shape. The lower surface of the cover rib 320 is a flat surface. As shown in FIG. 12, the lower end portion of the cover rib 320 is in contact with the rotation shaft 41 </ b> S of the supply roller 41 while the holder 30 is in contact with the first upper conveying surface 130 </ b> A of the stacking surface 150 </ b> A or slightly spaced upward. Are spaced apart upward.

  Other configurations of the third embodiment are the same as those of the first embodiment. For this reason, about the same structure as Example 1, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified.

  As shown in FIG. 13, when the holder 30 swings in a direction approaching the facing wall 51, the rotation shaft 41 </ b> S of the supply roller 41 is displaced upward so that the regulating portion 300 contacts the lower end of the cover rib 320. As a result, the swing of the holder 30 is restricted, and the maximum separation position L1 is defined. The maximum separation position L1 is set in the same manner as in the first embodiment.

  Similarly to the image reading device 1 of the first and second embodiments, the image reading device of the third embodiment having the above-described configuration can also suppress a reduction in separation performance due to an excessive number of sheets SH being stacked on the stacking surface 150A. .

  In the above, the present invention has been described with reference to the first to third embodiments. However, the present invention is not limited to the first to third embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

  For example, in the first embodiment, one of the holder rib 110 and the cover rib 120 may be eliminated, and the other of the holder rib 110 and the cover rib 120 may be lengthened by that amount.

  In the third embodiment, as shown in FIG. 11, the cover rib 320 is formed at a position facing the vicinity of the front end portion of the supply roller 41 from the front, but is not limited to this configuration. For example, the cover rib 320 may be formed at a position facing the vicinity of the rear end portion of the supply roller 41 from the rear. The pair of cover ribs 320 may be formed at positions facing the front and rear end portions of the supply roller 41 from the front and rear.

  The present invention can be used for an image reading apparatus, an image forming apparatus, a multifunction peripheral, or the like.

DESCRIPTION OF SYMBOLS 1 ... Sheet conveying apparatus (image reading apparatus), SH ... Sheet 150A ... Loading surface (1st upper conveying surface 130A, support surface 91A)
DESCRIPTION OF SYMBOLS 41 ... Supply roller, 41A ... Outer peripheral surface of supply roller 41S ... Rotation shaft of supply roller, 42 ... Separation roller, X42 ... Rotation axis 30 ... Holder, 50 ... Open / close cover, 51 ... Opposite wall part 100, 200, 300 ... Restriction part, 110 ... 1st convex part (holder rib)
120 ... 2nd convex part (cover rib), 210 ... 3rd convex part (holder rib)
211 ... tip part, 220 ... fourth convex part (cover rib), 221 ... opening part 221A ... inner peripheral edge of the opening part, 320 ... fifth convex part (cover rib)
3S: Reading unit (reading sensor), L1: Maximum separation position

Claims (7)

A loading surface on which sheets are stacked;
A supply roller for feeding out the sheets stacked on the stacking surface in the transport direction;
Sheets conveyed by the supply roller one by one, which are positioned downstream of the supply roller in the conveyance direction and rotate about a rotation axis extending in the width direction perpendicular to the conveyance direction on the stacking surface. Separating rollers that are transported in the transport direction while being separated into
A holder that is swingably supported around the rotation axis, and that rotatably supports the supply roller;
An opposing wall facing the stacking surface with the holder in between,
When the holder is swung in a direction approaching the facing wall and the supply roller is separated from the stacking surface, the maximum separation position where the outer peripheral surface of the supply roller is most separated from the stacking surface is defined. And a restricting portion for restricting the swing of the holder. The restricting portion includes a first convex portion projecting from the holder toward the opposing wall portion,
The sheet conveying apparatus according to claim 1, wherein the restricting portion defines the maximum separation position when the first convex portion and the opposing wall portion abut directly or indirectly. The restricting portion includes a second convex portion projecting from the facing wall portion toward the holder,
The sheet conveying apparatus according to claim 2, wherein the restriction portion defines the maximum separation position when the first convex portion and the second convex portion come into contact with each other. The restricting portion includes a third convex portion projecting from the holder toward the downstream in the transport direction;
A fourth convex part that protrudes from the opposing wall part toward the front third convex part and is formed with an opening through which the front end part of the front third convex part is inserted;
The sheet conveying apparatus according to claim 1, wherein the restricting portion defines the maximum separation position when the leading end abuts against an inner peripheral edge of the opening. The restricting portion includes a fifth convex portion protruding from the facing wall portion toward the rotation axis of the supply roller,
The sheet conveying apparatus according to claim 1, wherein the restriction portion defines the maximum separation position when the fifth convex portion comes into contact with the rotation shaft.   The opposing wall portion is between a first position that covers the holder, the supply roller, and the separation roller, and a second position that is spaced apart from the stacking surface and opens the holder, the supply roller, and the separation roller. The sheet conveying apparatus according to claim 1, wherein the opening / closing cover is displaceable.   The sheet according to any one of claims 1 to 6, further comprising a reading unit that is provided downstream of the separation roller in the conveyance direction and reads an image of the sheet conveyed by the supply roller and the separation roller. Conveying device.

Images