JP2013112512A - Sheet conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet conveying device capable of excellently conveying sheets of various sizes and materials.SOLUTION: Conveyance of a sheet is guided by a first lower guide part 41. The lower surface of the sheet faces a first lower guide surface 43 of the first lower guide part 41. A plurality of second lower projected rims 122 which extend in a conveyance direction are formed at both end parts of the first lower guide surface 43 in a right-left direction orthogonal to the conveyance direction of the sheet, and any second lower projected rim 122 is not formed at the center part therebetween.

Description

  The present invention relates to a sheet conveying apparatus for conveying a sheet.

  The image scanner includes a sheet conveying device that conveys a sheet along a conveying path that passes through an image reading unit.

  In order to reduce the size of the apparatus, the conveyance path is often formed in a curved shape. In this case, the sheet conveying apparatus includes a first guide and a second guide that are curved along the conveying path. The first guide and the second guide are provided so as to face one side and the other side of the sheet conveyed on the conveyance path, respectively, across the conveyance path. The sheet is conveyed while being guided along the conveyance path by the first guide and the second guide.

JP 2003-87499 A

  It has been studied to make an image scanner capable of reading a surface image such as an identification card or a credit card.

  Credit cards are made of hard materials such as plastic and are much harder than paper such as copy paper. Therefore, the posture during transportation and the force received from the first guide and the second guide during transportation differ between paper and a credit card. Therefore, depending on the configuration of the first guide and the second guide, one of the paper and the credit card can be transported satisfactorily, but the other cannot be transported satisfactorily.

  An object of the present invention is to provide a sheet conveying apparatus that can favorably convey sheets of various sizes and materials.

  In order to achieve the above object, a sheet conveying apparatus according to the present invention is a sheet conveying apparatus for conveying a sheet, and is configured such that a first surface on one side of the sheet is opposed to the sheet conveying apparatus. A first guide part for guiding the conveyance is included. A plurality of first protrusions extending in the sheet conveyance direction are provided on a first guide surface of the first guide portion, which faces the first surface of the sheet. The first protrusion is provided at both ends of the first guide surface in the width direction orthogonal to the transport direction, and is not provided at a central portion sandwiched between the both ends.

  Sheet conveyance is guided by the first guide unit. The first surface on one side of the sheet faces the first guide surface of the first guide portion. A plurality of first ridges extending in the conveyance direction are formed at both ends of the first guide surface in the width direction orthogonal to the conveyance direction of the sheet, and the first ridges are formed at the center between them. Not.

  As a result, when a sheet having a width larger than the width of the central portion of the first guide surface in the width direction passes through the portion facing the first guide surface, the first protrusion can contact the first surface of the sheet. . Therefore, the frictional force that acts on the sheet is reduced. On the other hand, a sheet having a width equal to or smaller than the width of the central portion of the first guide surface in the width direction is a case where the sheet is made of a hard material if a portion facing the central portion of the first guide surface is passed. Also, the first protrusion is transported without being damaged by rubbing.

  As a result, the sheet having a width larger than the width of the central portion of the first guide surface in the width direction can be transported satisfactorily with reduced resistance during transport. On the other hand, for a sheet having a width equal to or less than the width of the central portion of the first guide surface in the width direction, even if it is made of a hard material, it is possible to prevent the first protrusion from being scratched by rubbing, It can be transported well.

  Moreover, when the 1st protrusion is formed in the center part of the width direction of a 1st guide surface, when the sheet | seat which consists of hard materials passes through the part which opposes the center part, a 1st protrusion is by a sheet | seat. There is a risk of injury. If the first protrusion is scratched, the leading edge of the sheet may be caught on the scratched portion, which may hinder smooth conveyance of the sheet. Since the 1st protrusion is not formed in the center part of the width direction of the 1st guide surface, such a malfunction does not arise.

  In addition, the second guide portion is provided to face the first guide portion, and the conveyance of the sheet between the first guide portion and the second guide portion is guided by the first guide portion and the second guide portion. Good. In this case, the second surface on the other side of the sheet faces the second guide surface of the second guide portion. A plurality of second ridges extending in the conveyance direction are formed at both ends of the second guide surface in the width direction perpendicular to the sheet conveyance direction, and the second ridges are formed at the center between them. It is preferably not formed.

  Thereby, when the sheet | seat which has a width | variety larger than the width | variety of the center part of a 2nd guide surface in the width direction passes through the part which opposes a 1st guide surface, a 2nd protrusion contacts the 2nd surface of a sheet | seat. Therefore, the frictional force that acts on the sheet is reduced. On the other hand, if the sheet having a width equal to or smaller than the width of the center portion of the second guide surface in the width direction is passed through a portion facing the center portion of the second guide surface, the sheet is made of a hard material. Also, the second protrusion is transported without being damaged by rubbing.

  As a result, the sheet having a width larger than the width of the central portion of the second guide surface in the width direction can be transported satisfactorily with reduced resistance during transport. On the other hand, for a sheet having a width equal to or smaller than the width of the center portion of the second guide surface in the width direction, even if it is made of a hard material, it is possible to prevent the second protrusion from being damaged by rubbing, It can be transported well.

  Moreover, when the 2nd protrusion is formed in the center part of the width direction of a 2nd guide surface, when the sheet | seat which consists of hard materials passes through the part which opposes the center part, a 2nd protrusion is by a sheet | seat. There is a risk of injury. If the second protrusion is scratched, the leading edge of the sheet may be caught on the scratched portion, which may hinder smooth conveyance of the sheet. Since the 2nd protrusion is not formed in the center part of the width direction of the 2nd guide surface, such a malfunction does not arise.

  The central portion of the second guide surface is preferably recessed on the other side, that is, on the side opposite to the first guide surface side.

Thereby, in the part which opposes the center part of a 2nd guide surface, the space | interval between a 1st guide part and a 2nd guide part becomes large. Therefore, the sheet having a width equal to or smaller than the width of the center portion of the second guide surface in the width direction is passed through the space having the large interval, so that even if the sheet is made of a hard material, the sheet is the second guide. It is possible to prevent contact with the part with a strong force. As a result, the sheet can be prevented from being conveyed while being largely bent, and the sheet can be conveyed satisfactorily without damaging the sheet or leaving a bend mark on the sheet.
A second image reading unit for reading an image formed on the second surface of the sheet may be provided downstream of the second guide unit in the conveyance direction. In this case, it is preferable that a third guide unit for guiding sheet conveyance is provided between the second guide unit and the second image reading unit in the conveyance direction. The second guide surface on the other side of the sheet faces the third guide surface of the third guide portion. A plurality of third ridges extending in the conveyance direction are formed at both ends of the third guide surface in the width direction orthogonal to the conveyance direction of the sheet, and the third ridges are formed in the central portion between them. It is preferably not formed.

  Thereby, when a sheet having a width larger than the width of the central portion of the third guide surface in the width direction passes through a portion facing the third guide surface, the third protrusion contacts the second surface of the sheet. Therefore, the frictional force that acts on the sheet is reduced. On the other hand, if a sheet having a width equal to or smaller than the width of the center portion of the third guide surface in the width direction is passed through a portion facing the center portion of the third guide surface, the sheet is made of a hard material. Also, it is conveyed without being damaged by rubbing of the third protrusion.

  As a result, the sheet having a width larger than the width of the central portion of the third guide surface in the width direction can be transported satisfactorily with reduced resistance during transport. On the other hand, for a sheet having a width equal to or smaller than the width of the center portion of the third guide surface in the width direction, even if it is made of a hard material, it is possible to prevent the third protrusion from being damaged by rubbing, It can be transported well.

  Moreover, when the 3rd protrusion is formed in the center part of the width direction of a 3rd guide surface, when the sheet | seat which consists of hard materials passes through the part which opposes the center part, a 3rd protrusion is by a sheet | seat. There is a risk of injury. If the third protrusion is scratched, the leading edge of the sheet may be caught on the scratched portion, which may hinder smooth conveyance of the sheet. Since the 3rd protrusion is not formed in the center part of the width direction of the 3rd guide surface, such a malfunction does not arise.

  It is preferable that the sheet facing surface where the second surface of the sheet faces in the second image reading unit is in a position retracted to the other side with respect to the third guide surface.

  Accordingly, when the sheet moves from the portion facing the third guide surface to the portion facing the sheet facing surface of the second image reading unit, the leading edge of the sheet can be prevented from being caught on the second image reading unit. Therefore, the sheet can be conveyed better.

  The third guide surface is preferably in a position retracted to the other side with respect to the second guide surface.

  Thereby, when the sheet moves from the portion facing the second guide surface to the portion facing the third guide surface, the leading edge of the sheet can be prevented from being caught by the third guide portion. Therefore, the sheet can be conveyed better.

  A first image reading unit for reading an image formed on the first surface of the sheet may be provided downstream of the first guide unit in the conveyance direction. In this case, it is preferable that a fourth guide unit for guiding sheet conveyance is provided between the first guide unit and the first image reading unit in the conveyance direction. The first surface on one side of the sheet faces the fourth guide surface of the fourth guide portion. A plurality of fourth ridges extending in the conveyance direction are formed at both ends of the fourth guide surface in the width direction orthogonal to the sheet conveyance direction, and the fourth ridges are formed at the center between them. It is preferably not formed.

  As a result, when a sheet having a width larger than the width of the center portion of the fourth guide surface in the width direction passes through a portion facing the fourth guide surface, the fourth protrusion contacts the first surface of the sheet. Therefore, the frictional force that acts on the sheet is reduced. On the other hand, a sheet having a width equal to or smaller than the width of the center portion of the fourth guide surface in the width direction is a case where the sheet is made of a hard material if a portion facing the center portion of the fourth guide surface is passed. Also, it is conveyed without being damaged by the rubbing of the fourth protrusion.

  As a result, for a sheet having a width larger than the width of the central portion of the fourth guide surface in the width direction, the resistance during conveyance can be reduced and the sheet can be conveyed satisfactorily. On the other hand, for a sheet having a width equal to or less than the width of the center portion of the fourth guide surface in the width direction, even if it is made of a hard material, it is possible to prevent the fourth protrusion from being damaged by rubbing, It can be transported well.

  Moreover, when the 4th protrusion is formed in the center part of the width direction of a 4th guide surface, when the sheet | seat which consists of hard materials passes through the part which opposes the center part, a 4th protrusion is by a sheet | seat. There is a risk of injury. If the fourth protrusion is scratched, the leading edge of the sheet may be caught on the scratched portion, which may hinder smooth conveyance of the sheet. Since the 4th protrusion is not formed in the center part of the width direction of the 4th guide surface, such a malfunction does not arise.

  It is preferable that the sheet facing surface of the first image reading unit facing the first surface of the sheet is in a position retracted to one side with respect to the fourth guide surface.

  Thereby, when the sheet moves from the portion facing the fourth guide surface to the portion facing the sheet facing surface of the first image reading unit, the leading edge of the sheet can be prevented from being caught on the first image reading unit. Therefore, the sheet can be conveyed better.

  The fourth guide surface is preferably in a position retracted to one side with respect to the first guide surface.

  Thereby, when the sheet moves from the portion facing the first guide surface to the portion facing the fourth guide surface, the leading edge of the sheet can be prevented from being caught by the fourth guide portion. Therefore, the sheet can be conveyed better.

  In the central portion of the guide surface that guides the conveyance of the sheet in the width direction, it is preferable that a portion where no protrusion extending in the conveyance direction is formed extends over the entire region in the conveyance direction.

  This can further prevent the sheet from being damaged by rubbing of the ridges.

  A tray on which the sheet is placed and a pair of sheet width guide members for guiding both ends of the sheet in the width direction on the tray may be further provided. The pair of sheet width guide members are movable in the width direction to positions close to each other with a predetermined minimum width and positions spaced apart from each other with a predetermined maximum width, and a central portion of the first guide surface is It is preferable to have a width equal to or greater than the minimum width of the pair of sheet width guide members in the width direction.

  Thereby, if it is a sheet | seat which has the width | variety below the minimum width of a pair of sheet | seat width guide member, even if it is a case where it consists of a hard material, it can convey favorably, without being damaged.

  In the central portion of the first guide surface, a double feed sensor that detects double feed in which a plurality of sheets are overlapped and conveyed may be provided.

  A fine air layer is formed between the double-fed sheets. The ultrasonic double feed sensor detects the double feed of the sheet based on the presence or absence of ultrasonic attenuation by the air layer.

  Since the first protrusions are formed at both ends in the width direction of the first guide surface, a portion where the air layer is formed and a portion where the air layer is not formed (the first protrusion) between the both ends and the sheet. Where the strip and the sheet are in contact). On the other hand, since the first protrusion is not formed in the central portion of the first guide surface, an air layer having a substantially constant width is uniformly formed between the central portion and the sheet. Therefore, the attenuation of the ultrasonic wave by the air layer between the center portion of the first guide surface and the sheet becomes uniform, and the attenuation can be accurately canceled from the output from the ultrasonic double feed sensor. . As a result, the detection accuracy of double feed by the ultrasonic double feed sensor can be increased.

  According to the present invention, sheets of various sizes and materials can be transported satisfactorily.

FIG. 1 is an external perspective view of an image scanner 1 according to an embodiment of the present invention, and shows a state when the image scanner 1 is not used. FIG. 2 is an external perspective view of the image scanner 1 and shows a state when the image scanner 1 is used. FIG. 3 is a sectional view of the image scanner 1. FIG. 4 is a perspective view of the upper unit 5 shown in FIG. FIG. 5 is a cross-sectional view of the vicinity of the boundary between the first upper guide portion 33 and the first lower guide portion 41 and the second upper guide portion 84 and the second lower guide portion 114 shown in FIG. 3. FIG. 6 is a perspective view of the lower unit 6 shown in FIG. FIG. 7 is a plan view of the lower unit 6 and the supply tray 3.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
<Appearance structure of image scanner>

  As shown in FIG. 1, the image scanner 1 includes a scanner body 2, a supply tray 3 as an example of a tray, and a discharge tray 4.

  The scanner body 2 includes an upper unit 5 and a lower unit 6. A sheet discharge port 7 is formed across the upper unit 5 and the lower unit 6 on the front surface of the scanner body 2.

  Note that the front and rear, the left and right, and the top and bottom are defined when the image scanner 1 is viewed from the front side with the image scanner 1 placed on a plane. In each drawing after FIG. 1, in order to facilitate understanding of the drawing, the prescribed direction is indicated by an arrow as necessary.

  The upper unit 5 is coupled to the lower unit 6 so as to be swingable about an axis extending in the left-right direction along the front upper edge of the lower unit 6. Then, the upper unit 5 can be displaced by swinging into a normal posture inclined downward, that is, a posture shown in FIG. 2, and a maintenance posture (not shown) in which the rear end portion is lifted upward from the normal posture. is there. In a state in which the upper unit 5 is in the maintenance posture, the space between the upper unit 5 and the lower unit 6 is opened, and sheet jam processing and maintenance can be performed.

  As shown in FIG. 2, an operation display unit 8 is provided on the upper surface of the upper unit 5. A plurality of operation buttons 9 and a pilot lamp 10 are arranged on the operation display unit 8.

  The lower unit 6 includes side panels 11 each having a trapezoidal shape in side view at the left end and the right end. The pair of side panels 11 form the left and right side surfaces of the image scanner 1. In a state where the upper unit 5 is in the normal posture, the pair of side panels 11 sandwich the upper unit 5 from the left and right, and the left and right side surfaces of the upper unit 5 are covered. In this state, the upper surface of the upper unit 5 is disposed in substantially the same plane as the upper edge of each side panel 11.

  At the upper rear end portion of the lower unit 6, the upper surface of the center portion 12C in the left-right direction is inclined forward and downward. On the center portion 12C, a substantially rectangular plate-shaped main body side guide member 13 is fixedly disposed at the center in the left-right direction.

  The left end portion 12L on the left side and the right end portion 12R on the right side of the center portion 12C protrude upward from the center portion 12C and have a substantially rectangular parallelepiped shape. In a state where the upper unit 5 is in the normal posture, the upper surfaces of the left end portion 12L and the right end portion 12R are substantially flush with the upper surface of the upper unit 5. On the right side surface of the left end portion 12L and the left end surface of the right end portion 12R, there are formed tray support shafts (not shown) extending inward in the left-right direction on the same straight line extending in the left-right direction.

  The supply tray 3 is supported by two tray support shafts so as to be swingable about the tray support shaft. The supply tray 3 is swung to oppose the upper surface of the scanner main body 2 from above, that is, the posture shown in FIG. 1 and the inclination angle of the central portion 12C of the rear upper end of the lower unit 6 is substantially the same. Thus, it can be displaced to a use posture extending from the rear upper end of the scanner body 2 to the rear upper side, that is, the posture shown in FIG. The supply tray 3 is formed in a plate shape that is substantially the same shape as the planar shape of the scanner body 2. Therefore, the upper surface of the scanner main body 2 is covered with the supply tray 3 while the supply tray 3 is in the storage posture.

  A substantially rectangular plate-shaped tray-side guide member 14 is provided on the inner surface of the supply tray 3, that is, the surface facing the front upper side in the use posture. The tray side guide member 14 is fixedly disposed at the front end of the supply tray 3 and behind the main body side guide member 13 in a state where the supply tray 3 is in a use posture.

  In a state where the supply tray 3 is in a use posture, a substantially rectangular sheet supply port 15 extending in the left-right direction is opened in front of the central portion 12C of the rear upper end portion of the lower unit 6.

  In a state where the supply tray 3 is in a use posture, a pair of left and right sheet width guide members 16 are formed across the central portion 12C of the rear upper end of the lower unit 6 and the supply tray 3.

  Each sheet width guide member 16 includes a main body side guide member 17 and a tray side guide member 18.

  The main body side guide member 17 integrally includes a placement portion 19 and a width restriction portion 20. The placement portion 19 is disposed along the upper surface of the central portion 12C. The mounting portion 19 has a substantially rectangular plate shape. The placement portion 19 is formed in substantially the same shape as the main body side guide member 13. The width restricting portion 20 rises perpendicularly to the placement portion 19 from the outer edge in the left-right direction of the placement portion 19.

  Note that the concept of “orthogonal” includes not only the intersection at 90 ° but also the case of intersecting at an angle including a slight error at 90 °.

  The tray side guide member 18 integrally includes a placement portion 21 and a width restriction portion 22. The placement portion 21 is disposed along the upper surface of the central portion 12C. The mounting portion 21 has a substantially rectangular plate shape. The placement portion 21 is formed in substantially the same shape as the tray side guide member 14. The width restricting portion 22 rises perpendicularly to the placement portion 21 from the outer edge of the placement portion 21 in the left-right direction.

  A connecting shaft 23 extending in the left-right direction protrudes from the rear end portion of the width regulating portion 20 of the main body side guide member 17. The axis of the connecting shaft 23 coincides with the axis of the tray support shaft that is the swing fulcrum of the supply tray 3. The width restricting portion 22 of the tray side guide member 18 is formed with a portion overlapping the rear end portion of the width restricting portion 20 of the main body side guide member 17 in the left-right direction. The tip of the connecting shaft 23 is inserted through this overlapping portion. Accordingly, the tray side guide member 18 swings about the connecting shaft 23 as the supply tray 3 swings. The main body side guide member 17 and the tray side guide member 18 are arranged in the front-rear direction in a state where the supply tray 3 is in the use posture, and the width regulating portions 20 and 22 are formed in a rib shape extending in the front-rear direction.

  The pair of sheet width guide members 16 are provided so as to be able to approach / separate with the same movement amount with respect to the center between them as a center reference.

  In a state in which the pair of sheet width guide members 16 are closest to each other, the distance between the left and right width restricting portions 20 and 22 is the minimum width that is substantially the same as the length of the short side of the Western business card size. Then, between the pair of sheet width guide members 16, the Western side business card size sheet straddles on the main body side guide member 13, the tray side guide member 14, and the placement portions 19 and 21 of the sheet width guide member 16. Can be placed.

  In addition, in a state where the pair of sheet width guide members 16 are most separated from each other, the distance between the left and right width restricting portions 20 and 22 becomes the maximum width that is substantially the same as the length of the short side of the legal size paper. And between the pair of sheet width guide members 16, the main body side guide member 13, the tray side guide member 14 and the sheet width guide member 16 are placed on the placement portions 19 and 21 of the legal size sheet. The front end, that is, the front end can be placed.

  For a sheet having a size larger than the Western business card size and smaller than the legal size, the pair of sheet width guide members 16 are moved so that the distance between the left and right width restricting portions 20 and 22 is the width in the left and right direction of the sheet. , The main body side guide member 13, the tray side guide member 14, and the sheet width guide member 16 can be placed on the placement portions 19 and 21.

  Thus, the sheet is placed on the rear upper end of the lower unit 6 of the scanner body 2 and the supply tray 3 in the center between the pair of sheet width guide members 16, that is, in the left-right direction of the sheet supply port 15. Set to match the center.

  The discharge tray 4 is formed in a substantially rectangular plate shape. The discharge tray 4 is stored in the lowermost part of the lower unit 6, that is, the state shown in FIG. 1, and the state where the discharge tray 4 is pulled out from the sheet discharge port 7 to the front of the scanner body 2, that is, the state shown in FIG. It is provided to be displaceable. In a state where the discharge tray 4 is stored in the lowermost part of the scanner main body 2, the front surface 24 of the discharge tray 4 is substantially flush with the front surface 25 of the scanner main body 2 as shown in FIG. 1. On the other hand, when the discharge tray 4 is pulled out to the front of the scanner body 2, the upper surface 26 of the discharge tray 4 is opened upward as a sheet receiving surface as shown in FIG.

In addition, an auxiliary plate 27 is provided on the upper surface 26 of the discharge tray 4 so as to be swingable about an axis along the front edge of the discharge tray 4. The auxiliary plate 27 can be displaced by swinging into a posture lying down with respect to the upper surface 26 and a posture extending forward and upward from the front end portion of the upper surface 26 in a state where the discharge tray 4 is pulled out in front of the scanner body 2. It is.
<Internal configuration of image scanner>

  The upper unit 5 and the lower unit 6 include an upper frame 31 and a lower frame 32, respectively, as shown in FIG. A sheet supply port 15 is formed by the rear edge of the upper frame 31 and the rear edge of the lower frame 32.

  In the upper frame 31, a first upper guide portion 33, an upper CIS holding portion 34, and a final guide portion 35 as an example of a second guide portion are successively formed in this order from the rear side.

  The surface facing the lower frame 32 of the first upper guide portion 33, that is, the lower surface is a first upper guide surface 36 as an example of a second guide surface that guides the conveyance of the sheet. The first upper guide surface 36 extends with a relatively steep slope in the front and lower direction, curves so as to protrude rearward and lower in the middle, and inclines with a relatively gentle slope in the front and lower direction. It extends.

  The upper CIS holding portion 34 is formed as a substantially rectangular recess that is recessed forward and upward. An upper CIS unit 37 is fitted into the upper CIS holding portion 34. The upper CIS unit 37 includes a contact glass 38 as an example of a second image reading unit. The upper CIS unit 37 is provided with the contact glass 38 facing the lower frame 32 side. A coil spring 39 is interposed between the bottom surface of the upper CIS holding portion 34 and the upper CIS unit 37. Thereby, when the thickness of the sheet is large, the upper CIS unit 37 moves according to the thickness, and the sheet is conveyed while being in good contact with the contact glass 38.

  The final guide portion 35 extends forward and downward at substantially the same inclination angle as the front end portion of the first upper guide surface 36.

  In the lower frame 32, a guide portion 40, a first lower guide portion 41 as an example of a first guide portion, and a lower CIS holding portion 42 are successively formed in this order from the rear side.

  The upper surface of the guide portion 40 has substantially the same inclination angle as the upper surfaces of the placement portions 19 and 21 of the main body side guide member 13, the tray side guide member 14, and the sheet width guide member 16, which are placement surfaces on which sheets are placed. And formed in a substantially flat surface inclined forward and downward.

  A surface facing the upper frame 31 of the first lower guide portion 41, that is, an upper surface is a first lower guide surface 43 as an example of a first guide surface that guides sheet conveyance. A space is provided between the first lower guide surface 43 and the first upper guide surface 36 of the first upper guide portion 33. The first lower guide surface 43 is curved so as to protrude rearward and downward, corresponding to the curvature of the first upper guide surface 36, parallel to the front end portion of the first upper guide surface 36, and forwardly and downwardly. It extends.

  Note that the concept of “parallel” includes a case where one side is slightly inclined with respect to the other side and a case where one side is very gently curved.

  The lower CIS holding part 42 is formed as a substantially rectangular concave part that is recessed rearward and downward. A lower CIS unit 44 is fitted in the lower CIS holding portion 42. The lower CIS unit 44 includes a contact glass 45 as an example of a first image reading unit. The lower CIS unit 44 is provided with the contact glass 45 facing the upper frame 31 side.

  The lower frame 32 is formed with a supply roller accommodating portion 46 as a concave portion that is recessed rearward and downward across the central portions of the guide portion 40 and the first lower guide portion 41 in the left-right direction.

  The supply roller 51 is rotatably accommodated in the supply roller accommodating portion 46. Part of the peripheral surface of the supply roller 51 protrudes forward and upward from the upper surfaces of the guide portion 40 and the first lower guide portion 41. The supply roller 51 rotates counterclockwise when viewed from the right side during sheet conveyance.

  A sheet-like guide 52 is provided so as to straddle the upper surface of the guide portion 40 and the peripheral surface of the supply roller 51 protruding from the upper surface. The sheet-shaped guide 52 is arranged so that the center thereof coincides with the center of the supply roller 51 in the left-right direction in the left-right direction. The sheet-like guide 52 is made of a film. The sheet-shaped guide 52 has a base end fixed to the upper surface of the guide 40 and a free end in contact with the peripheral surface of the supply roller 51.

  As shown in FIGS. 3 and 4, a regulating member 53, a sheet pressing member 54, and a separation piece unit 55 are provided on the front upper side of the supply roller 51. The restriction member 53, the sheet pressing member 54, and the separation piece unit 55 are attached to the upper frame 31.

  The regulating member 53 is disposed on the downstream side in the sheet conveyance direction with respect to the sheet-like guide 52. The regulating member 53 is formed in a substantially triangular shape in a side view pointed toward the supply roller 51. In the cross section shown in FIG. 4, the restricting member 53 has a restricting surface 56 that extends substantially on the same straight line as the radius of the supply roller 51 that is orthogonal to the straight line extending along the upper surface of the guide portion 40.

  The sheet pressing member 54 is made of a leaf spring. The base end portion of the sheet pressing member 54 is attached to the rear end portion of the upper frame 31. The free end portion of the sheet pressing member 54 is in contact with the peripheral surface of the supply roller 51 from the front upper side.

  The separation piece unit 55 includes a separation piece 57 made of rubber. The separation piece 57 is disposed on the downstream side in the rotation direction of the supply roller 51 with respect to the regulating member 53. The surface of the separation piece 57 is in elastic contact with the peripheral surface of the supply roller 51 by the urging force of the spring 58.

  As shown in FIG. 3, LF rollers 61 and 62 are respectively provided at the front end portions of the first upper guide portion 33 and the first lower guide portion 41 so as to be rotatable about an axis extending in the left-right direction. . A part of the peripheral surface of the LF roller 61 protrudes rearward and downward from the lower surface (first upper guide surface 36) of the front end portion of the first upper guide portion 33. Further, a part of the peripheral surface of the LF roller 62 protrudes forward and upward from the upper surface (first lower guide surface 43) of the front end portion of the first lower guide portion 41. Then, due to the biasing force of the spring 63, the peripheral surface of the LF roller 61 is in elastic contact with the peripheral surface of the LF roller 62 from the front upper side.

Discharge rollers 64 and 65 are respectively provided at the final guide portion 35 of the upper frame 31 and the front end portion of the lower frame 32 so as to be rotatable about an axis extending in the left-right direction. A part of the peripheral surface of the discharge roller 64 protrudes rearward and downward from the lower surface of the final guide portion 35. Further, a part of the peripheral surface of the discharge roller 65 protrudes forward and upward from the upper surface of the front end portion of the lower frame 32. Then, due to the urging force of the spring 66, the peripheral surface of the discharge roller 64 is in elastic contact with the peripheral surface of the discharge roller 65 from the front upper side.
<Reading images with an image scanner>

  The image scanner 1 can selectively read images formed on the upper surface as an example of the second surface of the sheet and the lower surface as an example of the first surface. Further, the image scanner 1 can read images formed on both sides of the sheet in parallel. Hereinafter, sheet conveyance and image reading will be described in time series.

  The distance between the pair of sheet width guide members 16 is adjusted to the width of the sheet to be read. A sheet to be read is inserted between the pair of sheet width guide members 16 from the upper rear side. The sheet is placed on the placement portions 19 and 21 of the main body side guide member 13, the tray side guide member 14, and the sheet width guide member 16. At this time, the front end portion of the sheet slides on the placement portions 19 and 21 of the main body side guide member 13, the tray side guide member 14, and the sheet width guide member 16. The front end portion of the sheet moves on the guide portion 40 of the lower frame 32 through the sheet supply port 15. Further, the front end portion of the sheet slides on the guide portion 40 toward the supply roller 51.

  When a plurality of sheets are set, the central portion in the left-right direction at the tip of the lowermost sheet moves from the guide unit 40 onto the sheet-like guide 52. The central portion at the leading end of the sheet slides on the sheet-like guide 52 and is guided onto the peripheral surface of the supply roller 51. When the leading end of the lowermost sheet comes into contact with the peripheral surface of the supply roller 51, the lowermost sheet stops due to frictional resistance with the peripheral surface of the supply roller 51. Further, the upper sheet stops when its leading edge abuts against the regulating surface 56 of the regulating member 53. This completes the sheet setting.

  Further, the free end portion of the sheet pressing member 54 is lifted by the entry of the sheet, and the sheet pressing member 54 comes into contact with the upper surface of the sheet. The lowermost sheet is pressed against the peripheral surface of the supply roller 51 by the urging force of the sheet pressing member 54.

  When the supply roller 51 rotates counterclockwise as viewed from the right side, the lowermost sheet moves together with the peripheral surface of the supply roller 51 by the frictional force between the lowermost sheet and the peripheral surface of the supply roller 51. Further, due to the frictional force between the lowermost sheet and the sheet immediately above the uppermost sheet, the uppermost sheet is dragged and moved. When the leading ends of these sheets come into contact with the surface of the separation piece 57, the movement of the upper sheet is restricted by the separation piece 57, and only the lowermost sheet is the peripheral surface of the separation piece 57 and the supply roller 51. And pass through the nip part.

  The sheet that has passed through the nip portion between the separation piece 57 and the peripheral surface of the supply roller 51 is sandwiched between the first upper guide surface 36 of the first upper guide portion 33 and the first lower guide surface 43 of the first lower guide portion 41. The transport path is guided while being guided by the first upper guide surfaces 36 and 42.

  When the leading edge of the sheet comes into contact with the nip portion of the LF rollers 61 and 62, the leading edge of the sheet is drawn into the nip portion by the rotation of the LF rollers 61 and 62. Then, the peripheral surfaces of the LF rollers 61 and 62 come into contact with the upper and lower surfaces of the sheet, respectively, and a conveying force is applied to the sheet from the peripheral surfaces of the LF rollers 61 and 62. Thereby, the conveyance of the sheet is continued.

  Thereafter, as the conveyance of the sheet proceeds, the upper and lower surfaces of the sheet face the contact glass 38 of the upper CIS unit 37 and the contact glass 45 of the lower CIS unit 44, respectively. And in the light emission position of the contact glass 38 and 45, light is irradiated to the upper surface and lower surface of a sheet | seat. Reflected light on the upper and lower surfaces of the sheet is received by the image sensors incorporated in the upper CIS unit 37 and the lower CIS unit 44, respectively, thereby reading the images formed on the upper and lower surfaces of the sheet.

When the leading edge of the sheet comes into contact with the nip portion of the discharge rollers 64 and 65, the leading edge of the sheet is drawn into the nip portion by the rotation of the discharge rollers 64 and 65. The peripheral surfaces of the discharge rollers 64 and 65 are in contact with the upper and lower surfaces of the sheet, respectively, and a conveying force is applied to the sheet from the peripheral surfaces of the discharge rollers 64 and 65. Thereby, the conveyance of the sheet is continued. When the trailing edge of the sheet is separated from the discharge rollers 64 and 65, the sheet is discharged to the upper surface 26 of the discharge tray 4.
<Details of guide part of upper frame>

  As shown in FIG. 4, the first upper guide surface 36 of the first upper guide portion 33 of the upper frame 31 is continuous with the bending portion 71 that curves so as to protrude rearward and downward as a whole, and the bending portion 71. And an inclined portion 72 extending in a slanting forward and downward direction with a gentle gradient.

  A central portion in the left-right direction of the bending portion 71 is a card guide portion 73. In the first upper guide surface 36, the left and right side portions of the card guide portion 73 are general guide portions 74.

  The card guide part 73 has a width that is slightly larger than the length of the short side of the credit card in the left-right direction. The card guide portion 73 is formed of a curved surface that curves so as to protrude downward and downward with a small curvature, in other words, a large curvature radius.

  The general guide portion 74 has a steeply inclined portion 75, a curved portion 76, and a gently inclined portion 77. The steeply inclined portion 75 extends with a steeper slope than the inclined portion 72 in the forward and downward direction. The curved portion 76 is continuous with the steeply inclined portion 75. The curved portion 76 is curved so as to protrude rearward and downward with a larger curvature than the card guide portion 73, in other words, with a smaller radius of curvature. The gently inclined portion 77 is continuous with the curved portion 76. The gentle inclined portion 77 extends forward and downward with the same gradient as the inclined portion 72.

  Since the curvature of the card guide portion 73 is smaller than the curvature of the curved portion 76 of the general guide portion 74, the first upper guide surface 36 is formed with a concave portion 78 that is recessed forward and upward. The card guide portion 73 forms the bottom surface of the recess 78.

  The upper CIS unit 37 fitted to the upper CIS holding part 34 includes a holder 81. The holder 81 has a counter plate 82 that faces the lower CIS unit 44 shown in FIG. A glass fitting recess 83 into which the contact glass 38 is fitted is formed on the lower surface of the facing plate 82, that is, the surface facing the lower CIS unit 44. The contact glass 38 is held by the holder 81 by fitting the contact glass 38 into the glass fitting recess 83. The glass fitting recess 83 has a depth larger than the thickness of the contact glass 38. Therefore, the surface which is the sheet facing surface of the contact glass 38 is in a position retracted forward and upward from the lower surface of the facing plate 82 as shown in FIG.

  The holder 81 accommodates a CIS module that integrally includes an LED light source, a lens, and an image sensor.

  Further, a portion of the counter plate 82 behind the glass fitting recess 83 is formed as a second upper guide portion 84 as an example of a third guide portion for guiding sheet conveyance. As shown in FIG. 4, the second upper guide portion 84 extends to the vicinity of the front edge of the first upper guide portion 33. The lower surface of the second upper guide portion 84 is a second upper guide surface 85 as an example of a third guide surface that guides sheet conveyance. Further, as shown in FIG. 5, the second upper guide portion 84 is slightly inclined rearward and upward with respect to the surface of the contact glass 38. Thus, the second upper guide surface 85 is in a position retracted forward and upward from the first upper guide surface 36.

  As shown in FIG. 4, the first upper guide surface 36, the second upper guide surface 85, and the bottom surface of the final guide portion 35 are each provided with a first extending in the sheet conveying direction, except for the central portion in the left-right direction. A first upper ridge 91 as an example of two ridges, a second upper ridge 92 as an example of third ridges, and a third upper ridge 93 are formed. The first upper protrusion 91, the second upper protrusion 92, and the third upper protrusion 93 are formed in substantially the same position in the left-right direction, that is, on substantially the same straight line extending in the transport direction, except for some of them. Yes.

  Specifically, the first upper protrusion 91 is not formed in the card guide portion 73 in the first upper guide surface 36. A plurality of first upper protrusions 91 are formed in the general guide portion 74 at intervals in the left-right direction. Further, in the inclined portion 72, the first upper protrusion 91 is not formed in a portion having a width that is slightly larger than the width in the left-right direction of the card guide portion 73 at the center in the left-right direction. A plurality of first upper protrusions 91 are formed at intervals in the left-right direction at both sides of the central portion in the left-right direction.

  In the second upper guide surface 85, the second upper protrusion 92 is not formed in a portion having a width slightly larger than the width in the left-right direction of the card guide portion 73 at the center in the left-right direction. A plurality of second upper protrusions 92 are formed at intervals in the left-right direction on both sides of the central portion in the left-right direction.

  On the lower surface of the final guide portion 35, the third upper protrusion 93 is not formed in a portion having a width slightly larger than the width in the left-right direction of the card guide portion 73 at the center in the left-right direction. A plurality of third upper protrusions 93 are formed at intervals in the left-right direction at both sides of the central portion in the left-right direction.

Thereby, on the lower surface of the upper frame 31, the first upper protrusion 91 and the first protrusion 91 are formed over the entire region in the sheet conveying direction at a portion having the same width as the width of the card guide portion 73 in the center portion in the left-right direction. The second upper ridge 92 and the third upper ridge 93 are not formed.
<Details of guide part of lower frame>

  As shown in FIG. 6, the first lower guide surface 43 of the first lower guide portion 41 of the lower frame 32 has a curved portion 101 and an inclined portion 102 in order from the upstream side in the sheet conveying direction.

  The bending portion 101 faces the bending portion 71 of the first upper guide portion 33 from the lower rear side. The bending portion 101 protrudes rearward and lower with a smaller curvature than the card guide portion 73 of the first upper guide portion 33. It is curved to become.

  The inclined portion 102 is continuous with the bending portion 101. The inclined portion 102 extends forward and downward in parallel with the inclined portion 72 of the first upper guide portion 33.

  The lower CIS unit 44 fitted to the lower CIS holding part 42 includes a holder 111. The holder 111 has a counter plate 112 that faces the upper CIS unit 37. A glass fitting recess 113 into which the contact glass 45 is fitted is formed on the upper surface of the counter plate 112. The contact glass 45 is held by the holder 111 by fitting the contact glass 45 into the glass fitting recess 113. The glass fitting recess 113 has a depth larger than the thickness of the contact glass 45, and the surface of the contact glass 45 that is the sheet facing surface is smaller than the lower surface of the facing plate 112 as shown in FIG. It is in a position retracted rearward and downward.

  A CIS module that integrally includes an LED light source, a lens, and an image sensor is accommodated in the holder 111.

  A portion of the counter plate 112 behind the glass fitting recess 113 is formed as a second lower guide portion 114 as an example of a fourth guide portion for guiding sheet conveyance. As shown in FIG. 6, the second lower guide portion 114 extends to the vicinity of the front end edge of the first lower guide portion 41. The upper surface of the second lower guide portion 114 is a second lower guide surface 115 as an example of a fourth guide surface that guides sheet conveyance. Further, as shown in FIG. 5, the second lower guide portion 114 is slightly inclined rearward and downward with respect to the surface of the contact glass 45. Thereby, the second lower guide surface 115 is in a position retracted forward and downward from the first lower guide surface 43.

  6 and 7, the upper surface of the guide portion 40 of the lower frame 32, the first lower guide surface 43, and the second lower guide surface 115 are respectively seated except for the central portion in the left-right direction. A first lower ridge 121 extending in the transport direction, a second lower ridge 122 as an example of the first ridge, and a third lower ridge 123 as an example of the fourth ridge are formed. The first lower protrusion 121, the second lower protrusion 122, and the third lower protrusion 123 are formed on substantially the same position in the left-right direction, that is, on substantially the same straight line extending in the transport direction, except for some of them. Yes.

  Specifically, the first lower protrusion 121 is not formed on a portion of the upper surface of the guide portion 40 having a width slightly larger than the width in the left-right direction of the card guide portion 73 at the center in the left-right direction. A plurality of first lower protrusions 121 are formed at intervals in the left-right direction on both sides of the central portion in the left-right direction.

  In the first lower guide surface 43, the second lower protrusion 122 is not formed in a portion having a width slightly larger than the width in the left-right direction of the card guide portion 73 at the center in the left-right direction. A plurality of second lower protrusions 122 are formed at intervals in the left-right direction on both sides of the central portion in the left-right direction.

  In the second lower guide surface 115, the third lower protrusion 123 is not formed in a portion having a width slightly larger than the width in the left-right direction of the card guide portion 73 at the center in the left-right direction. A plurality of third lower protrusions 123 are formed at intervals in the left-right direction on both sides of the central portion in the left-right direction.

  Thereby, on the upper surface of the lower frame 32, the first lower protrusion 121, the first protrusion 121, and the second lower protrusion 121 are formed over the entire region in the sheet conveying direction at a portion having the same width as the width of the card guide portion 73 in the center portion in the left-right direction. The 2 lower protrusion 122 and the 3rd lower protrusion 123 are not formed.

A double feed sensor 124 for detecting the double feed of the sheet is disposed at the center of the first lower guide surface 43 where the second lower protrusion 122 is not formed. As the double feed sensor 124, an ultrasonic double feed sensor that detects the double feed of the sheet by the presence or absence of attenuation of the ultrasonic wave is employed.
<Effect>

  The first lower guide portion 41 guides the sheet conveyance. The lower surface of the sheet faces the first lower guide surface 43 of the first lower guide portion 41. A plurality of second lower protrusions 122 extending in the conveyance direction are formed at both ends of the first lower guide surface 43 in the left-right direction orthogonal to the sheet conveyance direction. The second lower protrusion 122 is not formed in the central portion between them.

  Thereby, when a sheet having a width larger than the width of the central portion of the first lower guide surface 43 in the left-right direction passes through a portion facing the first lower guide surface 43, the second lower protrusion 122 is formed on the lower surface of the sheet. Can touch. Therefore, the frictional force that acts on the sheet is reduced. On the other hand, if a sheet having a width equal to or smaller than the width of the central portion of the first lower guide surface 43 in the left-right direction passes through a portion facing the central portion of the first lower guide surface 43, the sheet is made of a hard material. Even in this case, the second lower protrusion 122 is transported without being damaged by rubbing.

  As a result, the sheet having a width larger than the width of the central portion of the first lower guide surface 43 in the left-right direction can be transported satisfactorily with reduced resistance during transport. On the other hand, for a sheet having a width equal to or less than the width of the central portion of the first lower guide surface 43 in the left-right direction, even if the sheet is made of a hard material, the second lower protrusion 122 may be damaged by rubbing. It can prevent and can convey well.

  Moreover, when the protrusion is formed in the center part of the width direction of the 1st lower guide surface 43, when the sheet | seat which consists of hard materials passes through the part which opposes the center part, a protrusion is damaged by a sheet | seat. There is a fear. If the ridge is scratched, the leading edge of the sheet may be caught on the scratched portion, which may hinder smooth conveyance of the sheet. Since no protrusion is formed at the center in the width direction of the first lower guide surface 43, such a problem does not occur.

  Further, the first upper guide portion 33 is provided to face the first lower guide portion 41. The upper surface of the sheet faces the first upper guide surface 36 of the first upper guide portion 33. A plurality of first upper protrusions 91 extending in the conveyance direction are formed at both ends of the first upper guide surface 36 in the left-right direction orthogonal to the sheet conveyance direction. The first upper protrusion 91 is not formed in the central portion between them.

  Thus, when a sheet having a width larger than the width of the central portion of the first upper guide surface 36 in the left-right direction passes through a portion facing the first lower guide surface 43, the first upper protrusion 91 is the upper surface of the sheet. To touch. Therefore, the frictional force that acts on the sheet is reduced. On the other hand, if a sheet having a width equal to or less than the width of the central portion of the first upper guide surface 36 in the left-right direction passes through a portion facing the central portion of the first upper guide surface 36, the sheet is made of a hard material. Even in this case, the first upper protrusion 91 is transported without being damaged by rubbing.

  As a result, the sheet having a width larger than the width of the central portion of the first upper guide surface 36 in the left-right direction can be transported satisfactorily with reduced resistance during transport. On the other hand, for a sheet having a width equal to or smaller than the width of the central portion of the first upper guide surface 36 in the left-right direction, even if the sheet is made of a hard material, the first upper protrusion 91 may be damaged by rubbing. It can prevent and can convey well.

  Further, in the case where a ridge is formed at the center portion in the width direction of the first upper guide surface 36, the ridge is damaged by the sheet when the sheet made of a hard material passes through a portion facing the center portion. There is a fear. If the ridge is scratched, the leading edge of the sheet may be caught on the scratched portion, which may hinder smooth conveyance of the sheet. Since no protrusion is formed at the center in the width direction of the first upper guide surface 36, such a problem does not occur.

  In the central portion of the first upper guide surface 36, a recess 78 is formed that is recessed on the side opposite to the first lower guide surface 43 side, that is, on the front upper side.

  Thereby, in the part which opposes the center part of the 1st upper guide surface 36, the space | interval between the 1st lower guide part 41 and the 1st upper guide part 33 becomes large. Therefore, by passing a sheet having a width equal to or less than the width of the center portion of the first upper guide surface 36 in the left-right direction through the space having the large interval, that is, the portion facing the center portion of the first upper guide surface 36, Even if the sheet is made of a hard material, the sheet can be prevented from coming into contact with the first upper guide portion 33 with a strong force. As a result, the sheet can be prevented from being conveyed while being largely bent, and the sheet can be conveyed satisfactorily without damaging the sheet or leaving a bend mark on the sheet.

  A contact glass 38 for reading an image formed on the upper surface of the sheet is provided on the downstream side in the transport direction with respect to the first upper guide portion 33. Further, a second upper guide portion 84 for guiding sheet conveyance is provided between the first upper guide portion 33 and the contact glass 38. The upper surface of the sheet faces the second upper guide surface 85 of the second upper guide portion 84. A plurality of second upper protrusions 92 extending in the conveyance direction are formed at both ends of the second upper guide surface 85 in the left-right direction orthogonal to the sheet conveyance direction. The second upper protrusion 92 is not formed in the central portion between them.

  Thereby, when a sheet having a width larger than the width of the central portion of the second upper guide surface 85 in the left-right direction passes through a portion facing the second upper guide surface 85, the second upper protrusion 92 is formed on the upper surface of the sheet. To touch. Therefore, the frictional force that acts on the sheet is reduced. On the other hand, if a sheet having a width equal to or smaller than the width of the center portion of the second upper guide surface 85 in the left-right direction passes through a portion facing the center portion of the second upper guide surface 85, the sheet is made of a hard material. Even in this case, the second upper protrusion 92 is transported without being damaged by rubbing.

  As a result, the sheet having a width larger than the width of the central portion of the second upper guide surface 85 in the left-right direction can be transported satisfactorily with reduced resistance during transport. On the other hand, for a sheet having a width equal to or less than the width of the center portion of the second upper guide surface 85 in the left-right direction, even if it is made of a hard material, the second upper protrusion 92 may be damaged by rubbing. It can prevent and can convey well.

  Further, when the protrusion is formed at the center portion in the width direction of the second upper guide surface 85, the protrusion is damaged by the sheet when the sheet made of the hard material passes through the portion facing the center portion. There is a fear. If the ridge is scratched, the leading edge of the sheet may be caught on the scratched portion, which may hinder smooth conveyance of the sheet. Since no protrusion is formed at the center in the width direction of the second upper guide surface 85, such a problem does not occur.

  The lower surface of the contact glass 38 is in a position retracted forward and upward with respect to the second upper guide surface 85.

  Thereby, when the sheet moves from the portion facing the second upper guide surface 85 to the portion facing the lower surface of the contact glass 38, it is possible to prevent the leading edge of the sheet from being caught on the contact glass 38. Therefore, the sheet can be conveyed better.

  Further, the second upper guide surface 85 is in a position retracted forward and upward with respect to the first upper guide surface 36.

  Accordingly, it is possible to prevent the leading edge of the sheet from being caught on the second upper guide portion 84 when the sheet moves from the portion facing the first upper guide surface 36 to the portion facing the second upper guide surface 85. Therefore, the sheet can be conveyed better.

  A contact glass 45 for reading an image formed on the lower surface of the sheet is provided downstream of the first lower guide portion 41 in the transport direction. Further, a second lower guide portion 114 for guiding sheet conveyance is provided between the first lower guide portion 41 and the contact glass 45. The lower surface of the sheet faces the second lower guide surface 115 of the second lower guide portion 114. A plurality of third lower protrusions 123 extending in the conveyance direction are formed at both ends of the second lower guide surface 115 in the left-right direction orthogonal to the sheet conveyance direction. The third lower protrusion 123 is not formed in the central portion between them.

  Thereby, when a sheet having a width larger than the width of the central portion of the second lower guide surface 115 in the left-right direction passes through a portion facing the second lower guide surface 115, the third lower protrusion 123 is formed on the lower surface of the sheet. Can touch. Therefore, the frictional force that acts on the sheet is reduced. On the other hand, if a sheet having a width equal to or smaller than the width of the center portion of the second lower guide surface 115 in the left-right direction passes through a portion facing the center portion of the second lower guide surface 115, the sheet is made of a hard material. Even in this case, the third lower protrusion 123 is transported without being damaged by rubbing.

  As a result, the sheet having a width larger than the width of the central portion of the second lower guide surface 115 in the left-right direction can be transported satisfactorily with reduced resistance during transport. On the other hand, for a sheet having a width equal to or smaller than the width of the center portion of the second lower guide surface 115 in the left-right direction, even if the sheet is made of a hard material, the third lower protrusion 123 may be damaged by rubbing. It can prevent and can convey well.

  Further, when the protrusion is formed at the center portion in the width direction of the second lower guide surface 115, the protrusion is damaged by the sheet when the sheet made of the hard material passes through the portion facing the center portion. There is a fear. If the ridge is scratched, the leading edge of the sheet may be caught on the scratched portion, which may hinder smooth conveyance of the sheet. Since no protrusion is formed at the center in the width direction of the second lower guide surface 115, such a problem does not occur.

  The upper surface of the contact glass 45 is in a position retracted rearward and downward with respect to the second lower guide surface 115.

  Thereby, when the sheet moves from the portion facing the second lower guide surface 115 to the portion facing the upper surface of the contact glass 45, the leading edge of the sheet can be prevented from being caught on the contact glass 45. Therefore, the sheet can be conveyed better.

  Further, the second lower guide surface 115 is in a position retracted rearward and downward with respect to the first lower guide surface 43.

  Thereby, when the sheet moves from the portion facing the first lower guide surface 43 to the portion facing the second lower guide surface 115, the leading edge of the sheet can be prevented from being caught on the second lower guide portion 114. Therefore, the sheet can be conveyed better.

  Further, a supply tray 3 on which sheets are placed, and a pair of sheet width guide members 16 for guiding both left and right ends of the sheet on the supply tray 3 are provided. The pair of sheet width guide members 16 are separated from each other in the left-right direction at positions close to the same minimum width as the length of the short side of a Western business card size, and at the same maximum width as the length of the short side of the legal size paper. It is possible to move to the position. As shown in FIG. 7, the central portion of the first lower guide surface 43 has a width equal to or larger than the minimum width of the pair of sheet width guide members 16 in the left-right direction.

  Thereby, if it is a sheet | seat which has the width | variety below the minimum width of a pair of sheet | seat width guide member 16, even if it consists of a hard material, it can convey favorably, without being damaged.

  In the central portion of the first lower guide surface 43, a double feed sensor 124 for detecting double feed in which a plurality of sheets are overlapped and conveyed is provided. As the double feed sensor 124, an ultrasonic double feed sensor is employed.

  Since the second lower protrusion 122 is not formed at the center of the first lower guide surface 43, the distance between the seat and the first lower guide surface 43 at the center is substantially uniform in the left-right direction. Become. As a result, the double feed detection accuracy by the double feed sensor 124 can be improved.

  As shown in FIG. 3, the path through which the sheet is conveyed is a so-called straight path that extends in one direction from the supply tray 3 to the discharge tray 4 without being folded back in a U shape. Thereby, in the image scanner 1, the sheet | seat which consists of hard materials can be conveyed favorably. Further, no protrusion is formed on the entire length of the conveyance path at the center in the left-right direction of the surface facing the sheet conveyance path. Therefore, when the credit card is transported through a portion facing the central portion, it is possible to suppress the embossed portion of the credit card from being scraped regardless of whether the surface of the credit card faces upward or downward.

  As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, although the second lower protrusion 122 formed on the first lower guide surface 43 of the lower frame 32 is an example of the first protrusion, the second lower protrusion 122 formed on the first upper guide surface 36 of the upper frame 31 is an example. One upper protrusion 91 may be an example of a first protrusion. In this case, the second lower protrusion 122 is an example of the second protrusion. The third lower protrusion 123 and the second upper protrusion 92 are examples of the third protrusion and the fourth protrusion, respectively.

  Further, as shown in FIG. 6, in the lower frame 32, a portion surrounding the supply roller 51 may be configured to be rotatable. In this case, it is preferable that concave portions into which fingers for holding the rotatable portion can be inserted are formed on both the left and right sides of the rotatable portion. Thereby, the part which can be rotated can be rotated easily. Moreover, when a recessed part is formed, it is preferable that the rib-shaped member for preventing the front-end | tip of a sheet | seat etc. to enter into a recessed part is formed. As a result, it is possible to prevent the sheet from jamming due to the sheet entering the recess.

  In the above-described embodiment, the image scanner 1 is taken up. However, the sheet conveying apparatus according to the present invention requires a mechanism for conveying a sheet, such as an image forming apparatus represented by a printer or a copying machine, in addition to the image scanner 1. It can be widely applied to devices that do.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

3 Supply tray 16 Sheet width guide member 33 First upper guide portion 36 First upper guide surface 38 Contact glass 41 First lower guide portion 43 First lower guide surface 45 Contact glass 84 Second upper guide portion 85 Second upper guide surface 91 First upper protrusion 92 Second upper protrusion 114 Second lower guide portion 115 Second lower guide surface 122 Second lower protrusion 123 Third lower protrusion 124 Double feed sensor

Claims (12)

A sheet conveying device for conveying a sheet,
The first surface of one side of the sheet is configured to oppose, and includes a first guide portion for guiding the conveyance of the sheet,
A plurality of first protrusions extending in the sheet conveyance direction are provided on a first guide surface of the first guide portion, which is opposed to the first surface of the sheet,
In the first guide surface, the first protrusion is provided at both ends in the width direction orthogonal to the conveyance direction, and is not provided at a central portion sandwiched between the both ends. The second guide portion is configured to face the first guide portion with a space therebetween and to face the second surface on the other side of the sheet, and further includes a second guide portion for guiding the conveyance of the sheet,
A plurality of second ridges extending in the transport direction are provided on a second guide surface of the second guide portion that faces the second surface of the sheet,
2. The sheet conveying apparatus according to claim 1, wherein the second protrusion is provided at both ends in the width direction on the second guide surface, and is not provided at a central portion sandwiched between the both ends.   The sheet conveying apparatus according to claim 2, wherein the central portion of the second guide surface is recessed on the other side. A second image reading unit provided on the downstream side in the transport direction with respect to the second guide unit and configured to read an image formed on the second surface of the sheet;
A third guide that is provided between the second guide portion and the second image reading portion in the transport direction and is configured such that the second surfaces of the sheets face each other, and guides the transport of the sheet. And further comprising
A plurality of third ridges extending in the transport direction are provided on a third guide surface of the third guide portion facing the second surface of the sheet,
4. The sheet conveying device according to claim 2, wherein the third protrusion is provided at both ends in the width direction on the third guide surface, and is not provided at a central portion sandwiched between the both ends. .   5. The sheet conveying apparatus according to claim 4, wherein a surface of the second image reading unit facing the second surface of the sheet is in a position retracted to the other side with respect to the third guide surface.   The sheet conveying apparatus according to claim 4, wherein the third guide surface is in a position retracted to the other side with respect to the second guide surface. A first image reading unit provided on the downstream side in the transport direction with respect to the first guide unit and configured to read an image formed on the first surface of the sheet;
It is provided between the first guide part and the first image reading part in the transport direction, and is configured to face the third guide part with a space therebetween, and to face the first surface of the sheet. And a fourth guide part for guiding the conveyance of the sheet,
A fourth guide surface facing the first surface of the sheet in the fourth guide portion is provided with a plurality of fourth protrusions extending in the transport direction,
The said 4th protrusion is provided in the both ends of the said width direction in the said 4th guide surface, and is not provided in the center part pinched | interposed into the said both ends. Sheet conveying device.   The sheet conveying apparatus according to claim 7, wherein a surface of the first image reading unit that faces the first surface of the sheet is in a position retracted to the one side with respect to the fourth guide surface.   The sheet conveying apparatus according to claim 7 or 8, wherein the fourth guide surface is in a position retracted to the one side with respect to the first guide surface. The central portion in the width direction extends in the entire conveying direction in the sheet passing space through which the sheet passes,
The sheet conveying apparatus according to any one of claims 1 to 9, wherein a protrusion extending in the conveying direction is not formed at a central portion in the width direction. A tray on which the sheet to be conveyed is placed;
A pair of guides for guiding both ends of the sheet in the width direction on the tray is provided so as to be movable between a position close to a predetermined minimum width and a position spaced apart by a predetermined maximum width in the width direction. A sheet width guide member,
The sheet conveyance device according to any one of claims 1 to 10, wherein the central portion of the first guide surface has a width equal to or greater than the minimum width in the width direction.   The sheet conveyance according to any one of claims 1 to 11, further comprising a double feed sensor that is disposed in the central portion of the first guide surface and detects a multifeed in which a plurality of sheets are overlapped and conveyed. apparatus.

Images