JP5597570B2 - Paper feeding device and image forming apparatus using the same - Google Patents

Description

  The present invention is applied to an image forming apparatus such as a copying machine, a facsimile apparatus, and a printer apparatus, and relates to a paper feeding apparatus used for feeding an image forming sheet, and an image forming apparatus using the same.

  FIG. 9 is an explanatory diagram for explaining a paper feeding device according to the background art. The sheet feeding device shown in FIG. 9 has a sheet feeding roller 110 that feeds out sheets P from a sheet bundle stored in a sheet feeding cassette 130, and a nip portion that is in contact with the sheet feeding roller 110 and has been multi-fed. And a roller roller 120 for separating paper. The paper feed roller 110 and the roller roller 120 are disposed at positions corresponding to approximately the center of the paper width (see, for example, Patent Document 1).

  In addition, the paper feeding device 100 includes a guide unit 152 that guides the paper P to the nip portion. The guide portion 152 has a length substantially the same as the length of the paper feed roller 110 and is disposed at a position corresponding to approximately the center of the paper width. The paper feed cassette 130 is provided with width cursors 140 and 140 for regulating the paper width.

Japanese Patent Laid-Open No. 2002-60075

  By the way, there is an image forming apparatus in which a paper feed cassette can be pulled out in a direction (X direction in the drawing) perpendicular to the paper transport direction. FIG. 10 is an explanatory diagram for explaining a state when the paper cassette 130 is pulled out in the X direction in such an image forming apparatus. As shown in FIG. 10, when the paper feed cassette 130 is pulled out in the X direction with the leading edge of the paper P placed on the guide portion 152, the sheet bundle that tries to stay in that position due to inertia is moved to the back side (in the X direction). As the cursor 140 on the upstream side tries to push out, a ridge A is generated on the paper P.

  In this state, when the paper feeding cassette 130 is further pulled out in the X direction, the bag A may be caught by the inner edge of the guide portion 152 and the paper P may be broken and damaged.

  An object of the present invention is to provide a paper feeding device that can reduce the risk of damage to a sheet, and an image forming apparatus using the paper feeding device.

The sheet feeding device according to the present invention is a sheet feeding device that feeds the sheet, and stores the frame and the sheet, and is orthogonal to a conveyance direction of the sheet from a predetermined sheet feeding position with respect to the frame. A storage unit movable in the pulling-out direction, and opposed to the frame with the sheet conveyance path interposed therebetween, and rotates in a state where the sheet stored in the storage unit positioned at the paper feeding position is nipped. Thus, the storage between the first and second rollers for feeding the sheet out of the storage unit and transporting the sheet and the nip portion for nipping the sheet in the first and second rollers. towards the part to the nip and a guide member having a guide surface for guiding the sheet, wherein the frame is in the upstream side of said sheet, the housing Has an inclined surface inclined toward the nip to receive the leading end of the sheet conveyed from the guide member, the conveying edges of the upstream side of the sheet of the sheet of the inclined surface The guide portion is arranged so as to be continuous with the edge portion on the upstream side in the direction and inclined toward the nip portion with a larger gradient than the inclined surface, and the end of the storage portion and the guide surface on the nip portion side There is an enlarged portion whose distance from the edge gradually increases from the end of the guide surface on the upstream side in the pulling direction toward the pulling direction.

  According to this configuration, when the storage unit is pulled out in the pull-out direction with the front end of the sheet resting on the guide surface, if a wrinkle comes to the sheet, the wrinkle is pulled out of the guide surface as the storage unit moves. It will hit the end on the upstream side. At this time, the guide surface is formed so that the distance between the storage portion and the edge on the nip portion side of the guide surface gradually increases from the upstream end in the pulling direction toward the pulling direction. The protruding amount by which the end portion on the upstream side in the direction protrudes from the storage portion is small. Then, when the heel hits the guide surface, the heel is hardly caught on the guide surface, and the sheet is guided so as to be scooped up by the guide surface, so that damage to the sheet is reduced.

  The guide member is further provided with a support member that supports the guide member, and the guide member is a plate-like elastic body that forms the guide surface, from the end portion of the support member on the nip portion side to the nip portion. It is preferable that it protrudes toward.

  According to this configuration, the guide surface that guides the sheet from the storage portion toward the nip portion is formed by the guide member supported by the support member. Since the support member must support the guide member that forms the guide surface so as to guide the sheet toward the nip portion, the support member is made of a high-strength material capable of supporting the guide member against the pressure of the sheet. Need to be configured. Here, if the guide member is not provided and the support member is extended to form the guide surface, the contact of the strong support member with the first and second rollers will damage the roller. In consideration of manufacturing errors, it is necessary to increase the separation distance between the support member and the first and second rollers.

  On the other hand, in order to appropriately convey the sheet, it is desirable to guide the sheet to a position as close as possible to the nip portion of the first and second rollers. Therefore, the sheet feeding device according to the present invention is arranged so that the guide member, which is a plate-like elastic body forming the guide surface, protrudes from the end portion of the support member toward the nip portion. The sheet can be guided to a position as close as possible to the nip portion by the guide member which is an elastic body while sufficiently separating the high support member from the first and second rollers.

  The guide member is preferably a resin film.

  The resin film is suitable as a plate-like elastic body that forms the guide surface of the sheet.

  The first roller is a paper feed roller that conveys the nipped sheet by driving and rotating, and the second roller is a separation roller that separates the sheet guided by the guide member. Preferably there is.

  According to this configuration, it is possible to prevent double feeding of sheets by the separation roller.

  Further, it is preferable to further include a pickup roller disposed upstream of the first roller in the sheet conveying direction so as to contact the upper surface of the sheet and feeding the sheet to the nip portion.

  According to this configuration, the sheet is sent to the nip portion by the pickup roller disposed upstream of the first roller in the sheet conveyance direction, so that the reliability of sheet conveyance is improved.

  An image forming apparatus according to the present invention includes the above-described paper feeding device and an image forming unit that forms an image on a sheet fed from the paper feeding device.

  According to this configuration, it is possible to reduce the possibility of damage to the sheet used for image formation.

  In the sheet feeding device and the image forming apparatus having such a configuration, the guide surface is configured such that the distance between the storage portion and the edge on the nip portion side of the guide surface gradually increases from the upstream end in the pulling direction toward the pulling direction. Therefore, the amount of protrusion from which the end portion of the guide surface on the upstream side in the pulling direction protrudes from the storage portion is small. As a result, when the heel hits the guide surface, the possibility that the heel is caught on the guide surface is reduced. As a result, the possibility that the sheet is damaged can be reduced.

1 is a cross-sectional view illustrating an overall configuration of a copying machine according to an embodiment of the present invention. FIG. 2 is a perspective view schematically showing an example of the configuration of the paper feeding device shown in FIG. 1. FIG. 3 is a view of the paper feed cassette shown in FIG. 2 as viewed from above. It is explanatory drawing which shows the guide plate shown in FIG. FIG. 3 is a perspective view illustrating an example of a configuration of a sheet feeding mechanism illustrated in FIG. 2. FIG. 6 is a cross-sectional view of the paper feed mechanism shown in FIG. 5 cut along a vertical plane along the paper transport direction. It is a perspective view which shows an example of a structure of the lower structure shown in FIG. FIG. 3 is an explanatory diagram for explaining a state in which a paper feeding cassette is pulled out in a pulling direction in the paper feeding device shown in FIG. 2. It is explanatory drawing for demonstrating the paper feeder which concerns on background art. FIG. 10 is an explanatory diagram for explaining a state in which the paper feeding cassette is pulled out to the front in the paper feeding device shown in FIG. 9.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted. FIG. 1 is a cross-sectional view for explaining the overall configuration of a copying machine according to an embodiment of the present invention. Note that arrows F and R in the drawings indicate the front side (F) of the apparatus and the rear side (R) of the apparatus when the paper feed cassette is mounted on the copying machine. First, an overall configuration of a copying machine 10 according to an embodiment of the present invention will be described with reference to FIG.

  The copying machine 10 according to the present embodiment is a center registration type copying machine, and is provided with four paper feeding devices 1 disposed at the lower part of the apparatus main body, and on the side and upper sides of these paper feeding devices 1. A sheet conveying section 2 provided, an image forming section 3 disposed above the sheet conveying section 2, a fixing section 4 disposed downstream of the image forming section 3 in the sheet conveying direction, and An image reading unit 5 composed of an optical member disposed above the image forming unit 3 and the fixing unit 4, and an automatic document feeder (ADF) 7 disposed above the image reading unit 5 so as to be openable and closable. And.

  The paper feeding device 1 is configured to feed a bundle of sheets P stacked on a paper feeding cassette 6 that is detachably attached to the apparatus main body by a rotation operation of a pickup roller 11 having an arc outer periphery. To the outlet side (right side in FIG. 1) (paper P is sent out in the length direction), and the paper is fed from the uppermost sheet P by being rolled by the paper-feeding portion 12 provided at the upper right end of each paper feed cassette 6. Each sheet is reliably fed to the sheet transport unit 2 one by one. The copying machine 10 is configured such that the insertion / removal direction of the paper feed cassette 6 with respect to the device body is substantially orthogonal to the paper feed direction of the paper P from the paper feed cassette 6 to the device body.

  Note that the paper P is an example of a sheet. The sheet may be, for example, an OHP film. The paper feed cassette 6 corresponds to an example of a storage unit.

  The paper transport unit 2 transports the paper P fed from the paper feeding device 1 toward the image forming unit 3 by the transport roller pair 21 and the registration roller pair 22, and further from the image forming unit 3 to the fixing unit 4. The paper P on which image formation has been performed is discharged onto a discharge tray 24 by a discharge roller pair 23.

  The image forming unit 3 forms a predetermined toner image on the paper P by an electrophotographic process, and has a photoconductive drum 31 having photoconductivity supported rotatably and a periphery of the photoconductive drum 31. A charging unit 32, an exposure unit 33, a developing unit 34, a transfer unit 35, a cleaner 36, and a charge eliminating unit 37.

  The charging unit 32 includes a charging wire to which a high voltage is applied, and applies a predetermined potential to the surface of the photosensitive drum 31 by corona discharge from the charging wire. The exposure unit 33 irradiates the photosensitive drum 31 with laser light output from a laser emitter based on image data of a document read by the image reading unit 5 described later via a polygon mirror and a reflecting mirror. The surface of the photosensitive drum 31 is selectively attenuated to form an electrostatic latent image on the surface of the photosensitive drum 31.

  The developing unit 34 develops the electrostatic latent image with toner and forms a toner image on the surface of the photosensitive drum 31. The transfer unit 35 transfers the toner image on the surface of the photosensitive drum 31 onto the paper P. In this copying machine, the transfer unit 35 is constituted by a transfer roller that is separated from the photosensitive drum 31 by a predetermined distance. The cleaner 36 removes toner remaining on the surface of the photosensitive drum 31 after transfer. The static elimination unit 37 removes residual charges on the surface of the photosensitive drum 31.

  The fixing unit 4 is disposed on the downstream side of the image forming unit 3 in the sheet conveying direction, and heats the sheet P on which the toner image is transferred in the image forming unit 3 between the heating roller 41 and the pressure roller 42. The toner image is fixed on the paper P.

  The image reading unit 5 irradiates a document placed on the contact glass 51 with light from an exposure lamp, and guides the reflected light to a photoelectric conversion unit including a CCD line sensor or the like through a reflecting mirror. The image information of the original is read. The exposure lamp and the reflecting mirror form a scanning operation unit, and the scanning operation unit moves on the contact glass 51 by moving the moving region 52 extending in the left-right direction in FIG. 1 at a predetermined speed. The entire surface of the placed document can be scanned and the image on the entire surface of the document can be read.

  Next, the configuration of the paper feeding device 1 will be described in detail with reference to FIGS. FIG. 2 is a perspective view schematically showing an example of the configuration of the paper feeding device 1 shown in FIG. FIG. 2 shows a state in which the paper feed cassette 6 is inserted into the apparatus main body and the paper feed cassette 6 is positioned at a paper feed position where paper can be fed. The paper feed cassette 6 can be pulled out to the front side (F) of the apparatus, and the direction of the arrow F is the direction in which the paper feed cassette 6 is pulled out. Hereinafter, the direction in which the paper cassette is pulled out is referred to as a pulling direction F.

  The sheet feeding device 1 shown in FIG. 2 includes a sheet feeding cassette 6 that stores a sheet bundle PP, and a sheet feeding mechanism 8 that feeds the sheet P stored in the sheet feeding cassette 6 to the sheet conveying unit 2. .

  FIG. 3 is a view of the paper feed cassette shown in FIG. 2 as viewed from above. The paper feed cassette 6 is configured by mounting and attaching a paper feed tray 62 on a tray frame 61. The tray frame 61 is detachably attached to the apparatus main body via a slide mechanism 61a. Then, by pulling a handle formed on the front cover 61b of the tray frame 61, the slide mechanism 61a slides, and the paper feed cassette 6 can be pulled out to the front. The user supplies the paper P to the paper feed tray 62 of the paper feed cassette 6 pulled out in this way.

  As shown in FIG. 2, the paper feed tray 62 includes a concave paper storage portion 62 a on which the paper P can be stacked and stored. At the bottom of the paper storage portion 62a, a paper width restriction unit 63 for restricting the width direction of the paper P (direction perpendicular to the paper conveyance direction), a length cursor 78 for restricting the length direction of the paper P, A length cursor rail member 79 for supporting this is disposed. A predetermined paper position corresponding to the size of the paper P is restricted by the paper width restriction unit 63 and the length cursor 78.

  The length cursor 78 is slidable on the length cursor rail member 79 in the length direction of the paper P, and the length cursor 78 and the inner wall surface of the paper feed tray 62 facing the length cursor 78 (inner right side in FIG. 2). The wall position) regulates the sheet position in the length direction of the sheet P (the direction along the sheet conveyance direction).

  A substantially plate-like lift member 65 that lifts the front end of the paper P in the paper feeding direction and makes contact with the pickup roller 11 is provided at the top of the paper width regulating unit 63. The lift member 65 is provided with a cutout portion provided so as to avoid the length cursor 78 and the length cursor rail member 79, and the length cursor 78 extends from the cutout portion to the upper surface of the lift member 65. To protrude.

  The lift member 65 is provided with two openings 65a. The width cursors 71a and 71b on the base plate 73 project from the upper surface of the lift member 65 from the two openings 65a.

  The paper width regulating unit 63 includes a pair of width cursors 71a and 71b that regulate the width direction of the paper P, a base plate 73 that supports the pair of width cursors 71a and 71b so as to be slidable, and a pair of width cursors 71a and 71b. And an unillustrated interlocking mechanism for interlocking.

  The width cursors 71a and 71b are slidable on the base plate 73 in the width direction of the paper P, and are separated from and connected to each other by an interlocking mechanism (not shown) to widen the distance (width) between the width cursors 71a and 71b. Or it has come to narrow. The wall surface 711a, 711b inside the width cursors 71a, 71b (the side on which the width cursors 71a, 71b are opposed) abuts on the paper P, whereby the width of the paper P is regulated.

  The width cursors 71a and 71b are provided with stopper members 72 and 77 for fixing the width cursors to the base plate. Then, after the user positions the width cursors 71a and 71b according to the width of the paper P, the width members 71a and 71b are fixed so as not to move by operating the stopper members 72 and 77. .

  Plate-shaped horizontal portions 713a and 713b extending inward in the horizontal direction are connected to the lower portions of the width cursors 71a and 71b and attached to the width cursors 71a and 71b.

  Referring to FIG. 2, the paper feed mechanism 8 is disposed above the paper feed cassette 6 positioned at the paper feed position, and is disposed downstream of the pickup roller 11 in the paper feed direction. A winding portion 12 and a guide plate 13 (guide member) are provided.

  The webbing unit 12 includes a paper feed roller 121 (first roller) and a separation roller 122 (second roller) that are disposed to face each other across the conveyance path of the paper P. The paper feed roller 121 and the separation roller 122 are in contact with each other to form a nip portion 123. Note that the paper feed roller 121 and the separation roller 122 are not necessarily in contact with each other, and for example, the paper is nipped in a state where the paper feed roller 121 and the separation roller 122 are opposed to each other with a distance of about the thickness of the paper. It may be.

  The guide plate 13 is supported by a support member 85 described later so as to be bridged between the paper feed cassette 6 and the nip portion 123. The guide plate 13 guides the paper P conveyed by the pickup roller 11 toward the nip portion 123.

  FIG. 4 is an explanatory view showing the guide plate 13 shown in FIG. The guide plate 13 is a plate-like member having elasticity, and is constituted by, for example, a resin film having a thickness of about 0.1 mm to 1.0 mm. As the resin film, for example, a polyethylene terephthalate (PET) film can be used. As such a PET film, for example, “Lumirror” (registered trademark) manufactured by Toray Industries, Inc. can be used.

  The guide plate 13 has an upper surface serving as a guide surface 131 that guides the paper P. The guide plate 13 is substantially rectangular. Then, an edge (side) 132 on the upstream side in the sheet conveyance direction of the guide plate 13 is arranged in a direction parallel to the pull-out direction F. The guide plate 13 includes an enlarged portion 134 having an edge portion (side) 133 of the guide plate 13 on the downstream side in the sheet conveyance direction (on the nip portion 123 side) that is inclined with respect to the edge portion 132 and a taper. The part 132 and the edge part 133 have a parallel part 135 that is substantially parallel.

  At the edge 133 of the enlarged portion 134, the width of the guide plate 13 (the distance between the edge 132 and the edge 133) gradually increases from the upstream end in the pull-out direction F toward the downstream in the pull-out direction F. Is provided with a taper.

  Since the guide plate 13 is disposed between the paper feed tray 62 and the nip portion 123, the enlarged portion 134 has a distance between the paper feed tray 62 and the edge 133 of the enlarged portion 134, more specifically. The distance along the sheet conveyance direction between the edge portion 621 that is the upper end portion of the wall surface on the downstream side in the sheet conveyance direction of the sheet feeding tray 62 and serves as a sheet take-out port, and the edge portion 133 is the upstream side in the drawing direction F of the guide plate 13. It gradually increases from the end toward the pulling direction F.

  The guide plate 13 is fixed to a support member 85 described later by, for example, an adhesive tape 136 attached to the lower surface of the guide plate 13. Further, the guide plate 13 is disposed so that the parallel portion 135 of the guide plate 13 faces the nip portion 123.

  FIG. 5 is a perspective view showing an example of the configuration of the paper feed mechanism 8 shown in FIG. FIG. 6 is a cross-sectional view of the paper feed mechanism 8 shown in FIG. 5 cut along a vertical plane along the paper transport direction. FIG. 6 also shows a sectional view of the paper feed cassette 6 positioned at the paper feed position.

  The paper feed mechanism 8 shown in FIGS. 5 and 6 includes an upper structure U including the pickup roller 11 and the paper feed roller 121, and a lower structure D provided at the lower part of the upper structure U and including the separation roller 122. Combined and configured.

  The upper structure U has a solenoid M for lifting the pickup roller 11 and a pickup roller 11 in a frame 81 in which a sheet metal is bent into a long bottomed container shape in a direction perpendicular to the paper conveyance direction. A holding member 82, a pickup roller 11, a paper feed roller 121, and a plurality of transport rollers 14 are accommodated.

  The frame 81 is disposed so as to protrude from the edge 621 side of the paper feed cassette 6 disposed at the paper feed position so as to cover the upper portion of the paper feed cassette 6. The pickup roller 11 and the paper feed roller 121 are pivotally supported at positions corresponding to approximately the center in the width direction of the paper P by a drive shaft extending in a direction orthogonal to the paper transport direction.

  The shaft of the paper feed roller 121 is pivotally supported by a frame 81, and the shaft of the pickup roller 11 is pivotally supported by a holding member 82. The driving force of a motor (not shown) is transmitted to the shafts of the paper feed roller 121 and the pickup roller 11 so that the paper feed roller 121 and the pickup roller 11 rotate.

  The peripheral surfaces of the pickup roller 11 and the paper feed roller 121 project from the opening provided on the bottom surface of the frame 81 to the lower part of the frame 81. Accordingly, the pickup roller 11 comes into contact with the upper surface of the paper P stored in the paper feed cassette 6, and the paper feed roller 121 comes into contact with the separation roller 122 provided in the lower structure D.

  A drive shaft 141 extending in a direction orthogonal to the paper transport direction is disposed downstream of the paper feed roller 121 in the frame 81, and a plurality of transport rollers 14 are pivotally supported by the drive shaft 141. The peripheral surface of each transport roller 14 protrudes from the opening provided on the bottom surface of the frame 81 to the lower portion of the frame 81 and comes into contact with a later-described transport roller 15 provided on the lower structure D.

  FIG. 7 is a perspective view showing an example of the configuration of the lower structure D shown in FIG. The lower structure D shown in FIG. 7 is configured such that, for example, a separation roller 122, a torque limiter 124, and a plurality of transport rollers 15 are housed in a frame 83 formed by bending a sheet metal.

  The frame 83 includes an upper guide surface 831 that guides the paper P, side plates 832 and 832 that support the guide surface 831, and front and rear side plates 833 and 833 that connect the side plates 832 and 832. On the upstream side of the guide surface 831 in the sheet conveyance direction, an inclined surface 84 is provided that is inclined so as to receive the leading end of the sheet P conveyed from the sheet feeding cassette 6.

  The separation roller 122 is disposed at a position facing the paper feed roller 121. The peripheral surface of the separation roller 122 protrudes upward from an opening 834 provided in the guide surface 831 so as to come into contact with the paper feed roller 121.

  The torque limiter 124 is connected to the separation roller 122 by a connecting shaft that extends in a direction orthogonal to the paper transport direction. The torque limiter 124 applies to the separation roller 122 rotational torque (hereinafter referred to as limit torque) in a direction that prevents the separation roller 122 from rotating in the direction in which the paper is conveyed.

  As the limit torque, when one sheet P is nipped between the sheet feeding roller 121 and the separation roller 122, the sheet feeding roller 121 transports the sheet P, so that the sheet P and the separation roller 122 When the two sheets of paper P are nipped between the paper feed roller 121 and the separation roller 122, the torque is smaller than the torque to follow and rotate the separation roller 122 by the frictional force between the two sheets. A torque value larger than the torque for causing the separation roller 122 to be driven to rotate by the frictional force generated between the sheets is set.

  As a result, when one sheet P is nipped between the sheet feeding roller 121 and the separation roller 122, the torque transmitted from the sheet feeding roller 121 to the separation roller 122 via the sheet P overcomes the limit torque. Thus, the sheet P is conveyed in the sheet conveying direction as the separation roller 122 is driven to rotate.

  On the other hand, when the two sheets P are nipped between the sheet feeding roller 121 and the separation roller 122, the limit torque overcomes the frictional force between the two sheets P, and the separation roller 122 stops rotating. Thus, the conveyance of the paper P on the side in contact with the separation roller 122 is stopped, or the paper P on the side in contact with the separation roller 122 is pushed back to the paper feed cassette 6 side by the reverse rotation of the separation roller 122. In this way, the separation roller 122 separates the overlapped sheets P and prevents the sheets P from being double-fed.

  On the downstream side of the separation roller 122 in the paper conveyance direction, a plurality of conveyance rollers 15 supported by a drive shaft (not shown) are arranged. Each transport roller 15 is disposed at a position facing each transport roller 14. The circumferential surface of each conveyance roller 15 protrudes upward from an opening provided in the guide surface 831 so as to come into contact with each conveyance roller 14.

  A support member 85 that is inclined toward the nip portion 123 between the paper feed roller 121 and the separation roller 122 is provided at the edge portion of the opening 834 on the upstream side in the paper conveyance direction of the separation roller 122. The support member 85 is configured as follows, for example. For example, the sheet metal of the inclined surface 84 is deformed so as to be pushed upward by pressing or the like at a position that is the upstream edge of the opening 834 in the sheet conveyance direction, and the inclination angle becomes larger than that of the inclined surface 84. Thus, a support member 85 having an inclined surface inclined toward the nip portion 123 is formed.

  In this case, the inclination angle changes smoothly and continuously from the inclined surface 84 to the support member 85.

  Then, the guide plate 13 is adhered to the upper surface of the support member 85 with the adhesive tape 136, and the guide plate 13 is fixed.

  Then, the pickup roller 11 comes into contact with the uppermost surface of the sheet bundle PP stored in the sheet feeding tray 62. In this state, when a motor (not shown) rotationally drives the pickup roller 11 and the paper feed roller 121, the paper P is conveyed toward the scooping section 12 by the pickup roller 11. The leading edge of the paper P is received by the inclined surface 84 in the conveyance path of the paper feeding mechanism 8, and the leading edge of the paper P is in contact with the upper surface (guide surface) of the guide plate 13, and the paper is moved along the inclination of the guide plate 13. P is guided toward the nip portion 123.

  When the paper P reaches the nip portion 123, the paper P is nipped between the paper feed roller 121 and the separation roller 122 and is transported to the transport rollers 14 and 15 by driving rotation of the paper feed roller 121. The paper P is further nipped by the transport rollers 14 and 15 and is transported to the paper transport unit 2 by driving rotation of the transport rollers 14 and 15.

  FIG. 8 is an explanatory diagram for explaining a state in which the paper feed cassette 6 is pulled out in the pulling direction F with the leading edge of the paper P placed on the guide plate 13 in the paper feeding device 1 shown in FIG. When the paper feed cassette 6 is pulled out in the pulling direction F with the leading edge of the paper P placed on the guide plate 13, the width cursor 71a tries to push out the paper bundle PP in the pulling direction F. At this time, in addition to the sheet bundle PP trying to stay at that position due to inertia, the pickup roller 11 is in contact with the uppermost sheet P, so that the sheet P is caused by friction between the pickup roller 11 and the sheet P.皺 A occurs in

  When the sheet feeding cassette 6 is further pulled out in the pulling direction F in this state, the ridge A hits the upstream end (arrow R side) of the guide plate 13 in the pulling direction F (the end portion of the enlarged portion 134). However, the distance between the edge portion 621 of the paper feed cassette 6 and the edge portion 133 of the enlargement portion 134 along the sheet conveyance direction is the shortest at the tip portion of the enlargement portion 134, and the guide plate 13 from the edge portion 621. The amount of protrusion is small. Thereby, the possibility that the hook A may be caught on the tip of the guide plate 13 is reduced. As a result, the risk of paper damage can be reduced.

  The distance along the sheet conveyance direction between the edge 621 of the paper feed cassette 6 and the edge 133 of the guide plate 13 gradually increases in the drawing direction F, and the enlarged portion 134 and the parallel portion 135 are smoothly continuous. Therefore, the possibility that the hook A is caught on the edge 133 of the guide plate 13 is reduced. As a result, the risk of paper damage can be reduced.

  If the bag A is caught by the guide plate 13 and the paper P is torn, the user must remove the pieces of the paper P, which is troublesome. Further, when the hook A is caught on the edge of the guide plate 13, the guide plate 13 may be peeled off from the support member 85. However, in the sheet feeding device 1, as described above, the possibility that the hook A is caught on the guide plate 13 is reduced. As a result, the user's trouble of removing pieces of the paper P is reduced, and the guide plate 13 is supported by the support member. The possibility of peeling from 85 is also reduced.

  Further, since the upstream side of the support member 85 that supports the guide plate 13 in the pull-out direction F is connected to the inclined surface 84 so that the inclination angle changes smoothly and continuously from the inclined surface 84, the support member 85 The risk of the hook A being caught at the upstream end in the pull-out direction F of 85 is reduced. As a result, the risk of paper damage can be reduced.

  Although an example in which the paper feeding device 1 according to the present invention is applied to a copying machine as an example of an image forming apparatus has been shown, the present invention is not limited to this, and may be applied to a printer other than a copying machine, a facsimile, a multifunction machine thereof, or the like. Applicable. Moreover, the structure which is not provided with the pick-up roller 11 like the paper feeder of patent document 1, for example may be sufficient. Further, the arrangement of the paper feed roller 121 and the separation roller 122 may be interchanged. In addition, the first and second rollers are not necessarily the paper feed roller 121 and the separation roller 122, and may be a pair of rollers for paper feed (conveyance).

DESCRIPTION OF SYMBOLS 1 Paper feeder 2 Paper conveyance part 3 Image formation part 4 Fixing part 5 Image reading part 6 Paper feed cassette 8 Paper feed mechanism 10 Copying machine 11 Pickup roller 12 Rolling part 14, 15 Conveyance roller 21 Conveyance roller pair 22 Registration roller pair 23 Discharge roller pair 24 Discharge tray 31 Photosensitive drum 34 Developing unit 35 Transfer unit 41 Heating roller 42 Pressure roller 61a Slide mechanism 61 Tray frame 61b Front cover 62 Paper feed tray 62a Paper storage portion 65 Lift members 71a and 71b Width cursor 72 , 77 Stopper member 81, 83 Frame 82 Gear box 84 Inclined surface 85 Support member 121 Paper feed roller 122 Separating roller 123 Nip part 124 Torque limiter 130 Paper feed cassette 131 Guide surface 132, 133 Edge 134 Enlarged part 135 Parallel 136 adhesive tape 141 drive shaft 621 edge 831 guide surface 832 and 833 plate 834 opening D undercarriage P Paper U superstructure

Claims (6)

A sheet feeding device for feeding the sheet,
Frame,
A storage unit that stores the sheet and is movable with respect to the frame from a predetermined sheet feeding position in a pull-out direction orthogonal to the sheet conveyance direction;
The sheet is fed out from the storage unit by rotating in a state where the sheet stored in the storage unit positioned opposite to the frame with the conveyance path of the sheet positioned at the paper feeding position is nipped. And first and second rollers for conveying
A guide member having a guide surface for guiding the sheet from the storage portion toward the nip portion between the storage portion and a nip portion that nips the sheet in the first and second rollers;
With
The frame has an inclined surface that is inclined toward the nip portion so as to receive the leading end of the sheet conveyed from the storage unit on the upstream side in the conveyance direction of the sheet,
The guide member is
The edge on the upstream side in the sheet conveyance direction is continuous with the edge on the upstream side in the sheet conveyance direction of the inclined surface, and the guide surface is inclined toward the nip portion with a larger gradient than the inclined surface. Arranged as
A sheet feeding device having an enlarged portion in which a distance between the storage portion and an end edge of the guide surface on the nip portion side gradually increases from an end portion of the guide surface on the upstream side in the pulling direction toward the pulling direction. A support member for supporting the guide member;
The guide member is
The sheet feeding device according to claim 1, wherein the sheet feeding device is a plate-like elastic body that forms the guide surface, and protrudes from an end portion of the support member on the nip portion side toward the nip portion.   The sheet feeding device according to claim 1, wherein the guide member is a resin film. The first roller is a paper feed roller that conveys the nipped sheet by driving and rotating,
The sheet feeding device according to claim 1, wherein the second roller is a separation roller that separates a sheet guided by the guide member.   The pickup roller according to any one of claims 1 to 4, further comprising a pickup roller disposed upstream of the first roller in a conveyance direction of the sheet so as to contact the upper surface of the sheet and feeding the sheet to the nip portion. The sheet feeder according to item 1. A paper feeding device according to any one of claims 1 to 5,
An image forming apparatus comprising: an image forming unit that forms an image on a sheet fed from the sheet feeding device.

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