JP2023121585A - Sheet feeder and image formation device equipped therewith - Google Patents

Abstract

To provide a sheet feeder capable of stably feeding sheets and an image formation device equipped with the sheet feeder.SOLUTION: A sheet feeder 6 includes: a pickup roller 60 for drawing out the topmost sheet Pt from the loaded sheet P; a supply roller 61 for supplying the topmost sheet Pt drawn out by the pickup roller 60 to a sheet conveyance path S; and a separation member (separation roller 62) arranged to face the supply roller 61 and separating the topmost sheet Pt drawn out by the pickup roller 60 from other sheets Po. The supply roller 61 and the separating member (separating roller 62) are integrally movable reciprocally in a supply direction F of the sheet P and in a direction D intersecting the axis δ1 direction of the supply roller 61.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sheet feeding device and an image forming apparatus having the same.

A sheet feeding device that feeds sheets to a sheet conveying path generally includes a pickup roller that pulls out the uppermost sheet among the stacked sheets, and supplies the uppermost sheet that is pulled out by the pickup roller to the sheet conveying path. A supply roller and a separating member arranged to face the supply roller are provided. The separating member forms a nip area with the supply roller and separates the topmost sheet from the other sheets by the frictional force generated in the nip area. 2. Description of the Related Art Conventionally, as a sheet feeding device, there is known one that includes a biasing member that biases a separating member toward the supply roller (see, for example, Japanese Patent Application Laid-Open No. 2002-100003).

JP 2016-78983 A

However, a sheet entering the nip area may pull the separating member away from the feed roller and the nip area between the feed roller and the separating member and the nip pressure in the nip area may not be maintained. If the nip area and the nip pressure are not maintained, the sheet cannot be reliably sandwiched between the supply roller and the separation member, and thus it becomes difficult to stably feed the sheet. For example, as shown in FIG. 8, in the conventional sheet feeding device 9 disclosed in Japanese Patent Application Laid-Open No. 2002-200002, when a sheet P having a high rigidity such as a cardboard is curved and sent to the sheet conveying path S, , the curved sheet P presses the separation member 91 in the direction (arrow Q shown in FIG. 8) in which the separation member 91 is pulled away from the supply roller 90 . At this time, there is a risk that the pressing force of the sheet P against the separation member 91 will reach a level sufficient to separate the separation member 91 from the supply roller 90 . When the separation member 91 is pulled away from the supply roller 90, the nip area is not formed between the supply roller 90 and the separation member 91, or the nip pressure in the nip area is insufficient. cannot perform the function of separating from other sheets. If the uppermost sheet is not separated from the other sheets by the separation member 91, the sheets are pulled out while the other sheets overlap the uppermost sheet, which is a so-called sheet feeding. Therefore, in the conventional sheet supply device 9, there is a problem that it is difficult to stably feed the sheet P having high rigidity to the sheet conveying path S or the like.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet feeding device capable of stably feeding a sheet and an image forming apparatus having the same.

In order to achieve the above object, the sheet feeding device described in the present application includes a pickup roller that pulls out the uppermost sheet among the stacked sheets, and supplies the uppermost sheet that is pulled out by the pickup roller to a sheet conveying path. A sheet feeding device comprising: a feeding roller; and a separating member disposed facing the feeding roller and separating the uppermost sheet pulled out by the pickup roller from other sheets, wherein the feeding roller and the separating member is integrally provided so as to be reciprocally movable in a direction intersecting the supply direction of the sheet and the axial direction of the supply roller.

Further, in the sheet supply device, the sheet conveying path may be curved on the downstream side of the supply roller.

Further, the sheet supply device may further include a first biasing member that biases the supply roller and the separation member in a direction to contact each other.

Further, in the sheet feeding device, the separating member is a separating roller, and is provided so as to be reciprocally movable in a direction intersecting the sheet feeding direction and the axial direction of the feeding roller. A holder portion that supports the shaft portion of the roller may be further provided.

Further, in the sheet feeding device, the holder section may have a second biasing member that biases the holder section in a direction to return it to a predetermined position.

Further, in the sheet feeding device, the separating member is a separating roller, and is provided so as to be reciprocally movable in a direction intersecting the sheet feeding direction and the axial direction of the feeding roller. A holder portion for supporting the shaft portion of the roller is further provided, the holder portion has a second biasing member that biases the holder portion in a direction to return to a predetermined position, and the elasticity of the first biasing member is increased. The force may be greater than the elastic force of the second biasing member.

Further, in the sheet feeding device, the second biasing member is provided outside the holder portion, and a biasing member of the second biasing member is provided on the opposite side of the holder portion with respect to the second biasing member. A movement restricting portion that restricts movement of the holder portion in the direction may be provided.

Further, in the sheet feeding device, the holder portion includes a pair of first wall surfaces facing each other in the axial direction of the supply roller, and a second wall surface connecting one side edge of the pair of first wall surfaces to each other. and a wall surface, wherein the pair of first wall surfaces includes a supply roller support hole that supports the shaft of the supply roller, a separation roller support hole that supports the shaft of the separation roller, and may be provided.

Further, in the sheet feeding device, the holder portion includes a pair of first wall surfaces facing each other in the axial direction of the supply roller, and a second wall surface connecting one side edge of the pair of first wall surfaces to each other. and a bottom wall portion connecting the edges of the pair of first wall surfaces and the edges of the second wall surfaces to each other. A supply roller support hole that supports the shaft portion and a separation roller support hole that supports the shaft portion of the separation roller may be provided, and the second biasing member may be engaged with the bottom wall portion. .

Further, in the sheet feeding device, the separation roller support hole may be an elongated hole extending in the reciprocating direction of the holder portion.

Further, in the sheet feeding device, a bearing portion is fitted to each of the shaft portion of the supply roller and the shaft portion of the separation roller, and the supply roller support hole is configured to support the shaft portion of the supply roller at the shaft portion. The bearing portion may support the separation roller, and the separation roller support hole may support the shaft portion of the separation roller with the bearing portion of the shaft portion.

Further, in the sheet supply device, the holder portion may be arranged outside the sheet of the maximum size that can be supplied by the supply roller in the axial direction of the supply roller.

Further, in the sheet supply device, a support rail portion for supporting the holder portion is provided on one side of the holder portion in a direction orthogonal to the axial direction of the supply roller, and a support rail portion is provided on one side portion of the holder portion. may be provided with a groove portion that is slidably fitted to the support rail portion.

An image forming apparatus according to the present application includes the sheet feeding device.

According to the present invention, the sheet can be sent stably.

2 is a schematic front view showing the internal structure of the image forming apparatus according to Embodiment 1; FIG. 2 is a schematic front view showing the internal structure of the sheet feeding device according to Embodiment 1; FIG. 3 is a schematic side view of the inside of the sheet feeding device of FIG. 2 as viewed from the upstream side in the sheet feeding direction; FIG. 3 is a schematic plan view showing the internal structure of the sheet feeding device of FIG. 2; FIG. It is a schematic perspective view which shows a holder part. FIG. 6 is a schematic view of the inside of the holder portion of FIG. 5 viewed from the axial direction of the supply roller; FIG. 6 is a schematic front view showing the behavior of the holder part of FIG. 5; FIG. 10 is a schematic front view showing the internal structure of a conventional sheet feeding device;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the same code|symbol is attached|subjected to the same component among each embodiment described below, and the description which overlaps with these components is abbreviate|omitted.

(Embodiment 1)
-Overall Configuration of Image Forming Apparatus-
First, the overall configuration of the image forming apparatus A according to the first embodiment will be described.

FIG. 1 is a schematic front view showing the internal structure of an image forming apparatus A according to Embodiment 1. FIG. In the drawings, the symbol X indicates the width direction (depth direction), the −X direction (minus X direction) is the front direction, and the +X direction (plus X direction) is the rear direction. Symbol Y indicates the left-right direction orthogonal to the width direction X, with the −Y direction (minus Y direction) being the left direction and the +Y direction (plus Y direction) being the right direction. The symbol Z indicates the vertical direction, with the −Z direction (minus Z direction) being the downward direction and the +Z direction (plus Z direction) being the upward direction. These settings are the same in the subsequent embodiments.

The image forming apparatus A is an electrophotographic image forming apparatus, and is an intermediate transfer type color multifunction machine capable of printing a full-color image. The image forming apparatus A includes an image reading section 1 and an image forming apparatus main body B (see FIG. 1). In this embodiment, the image forming apparatus A uses yellow (Y), magenta (M), cyan (C), and black (K) toners for printing.

The image reading unit 1 reads an image from a document, and is provided in the upper part of the image forming apparatus A. As shown in FIG. The image reading section 1 has a document reading device 10, a document table 11, and an automatic document processing device 12 (see FIG. 1).

The document reading device 10 irradiates a document with light and reads an image from the document based on the reflected light. The document table 11 is a portion on which a document is placed by a user, and is provided above the document reading device 10 . The document table 11 is made of transparent glass. The automatic document processor 12 automatically and continuously conveys the document inserted by the user to the document reader 10 , and is provided above the document table 11 . The image of the document is read by the document reading device 10 while the document is placed on the document table 11 or conveyed to the document reading device 10 by the automatic document processing device 12 .

The image forming apparatus main body B includes an image forming section 2, an intermediate transfer member 3, a secondary transfer section 40, a fixing device 41, a sheet storage section 42, a manual feed tray 43, a sheet supply device 6, and a sheet ejection. and a portion 44 (see FIG. 1). The image forming apparatus A is provided with a sheet conveying path S for conveying the sheet P from the sheet containing portion 42 or the manual feed tray 43 to the sheet discharging portion 44 . The sheet conveying path S includes conveying rollers 5a and 5b for conveying the sheet P along the sheet conveying path S, and rollers 5a and 5b for temporarily stopping the sheet P conveyed from the sheet containing portion 42 or the manual feed tray 43 to move the leading edge of the sheet P. and a registration roller 5c for aligning.

The image forming section 2 forms a toner image of each color based on image data, and includes an exposure device 20, a developing device 21, an image carrier 22, a charger 23, and a cleaning unit 24. (See Figure 1).

The exposure device 20 forms an electrostatic latent image corresponding to each color on the image carrier 22 by exposing the surface of the image carrier 22 charged by the charger 23 to light according to each color. The developing device 21 develops (visualizes) the electrostatic latent image formed on the surface of each image carrier 22 by toner of each color (Y, M, C, K) supplied from the toner cartridge T. It forms a toner image. The image carrier 22 has an electrostatic latent image formed on its surface, and is rotated in a predetermined direction by driving a main motor (not shown). A toner image visualized on the image carrier 22 is conveyed to the intermediate transfer member 3 by rotational driving of the image carrier 22 . The charger 23 uniformly charges the surface of the image carrier 22 to a predetermined potential. The cleaning unit 24 removes and collects toner remaining on the surface of the image carrier 22 after development and image transfer. A toner image of each color is formed on the surface of each image carrier 22 by a series of operations based on the above configuration.

The intermediate transfer member 3 is used for primary transfer and is arranged above the image carrier 22 . Here, “primary transfer” refers to the transfer of each color toner image formed on the image carrier 22 onto the intermediate transfer belt 30 . The intermediate transfer body 3 has an intermediate transfer belt 30, a drive roller 31, a driven roller 32, and a primary transfer roller 33 (see FIG. 1).

The intermediate transfer belt 30 is an endless belt that rotates in a predetermined direction, and is suspended between a drive roller 31 and a driven roller 32 . The toner images of respective colors visualized on the image carrier 22 are successively superimposed and transferred onto the intermediate transfer belt 30 and conveyed to the secondary transfer portion 40 by the rotation of the intermediate transfer belt 30 . The drive roller 31 is a roller driven to rotate in a predetermined direction by being driven by a belt motor (not shown), and is provided on one end side of the intermediate transfer member 3 . The rotation of the drive roller 31 causes the intermediate transfer belt 30 to rotate. The driven roller 32 is a roller rotatably provided along the intermediate transfer belt 30 . The driven roller 32 is rotated as the intermediate transfer belt 30 rotates. The primary transfer rollers 33 are arranged in rows so as to correspond to the image carriers 22 via the intermediate transfer belt 30 . By applying a transfer bias to the primary transfer roller 33 , the toner image on the image carrier 22 is transferred to the intermediate transfer belt 30 .

The secondary transfer section 40 serves for secondary transfer, and is arranged on the sheet conveying path S. As shown in FIG. Here, the term “secondary transfer” refers to the transfer of each color toner image transferred onto the intermediate transfer belt 30 onto the sheet P. As shown in FIG.

The fixing device 41 heats and melts the toner image that has been secondarily transferred onto the sheet P to fix it onto the sheet P, thereby fixing the toner image onto the sheet P. It is provided downstream of the transfer section 40 .

The sheet storage unit 42 is arranged in the lower part of the image forming apparatus A, and has a sheet cassette 45 that stores sheets P to be supplied to the image forming apparatus main body B of the image forming apparatus A. As shown in FIG. The sheet cassette 45 is provided with an elevating plate 46 that supports the sheet P from the bottom surface. The lifting plate 46 is biased upward by a biasing member (not shown).

A sheet P can be placed on the manual feed tray 43, and the manual feed tray 43 is attached to the image forming apparatus main body B so as to be rotatable.

The sheet feeding device 6 feeds the sheet P from the sheet cassette 45 of the sheet containing portion 42 to the sheet conveying path S, and is provided on the starting end side of the sheet conveying path S. As shown in FIG. The sheet feeding device 6 will be described later in detail.

The sheet discharge section 44 is provided in the upper portion of the image forming apparatus A, and loads and pulls the printed sheet P face down.

The image forming apparatus A as described above performs printing on the sheet P as follows. First, the image forming section 2 forms a toner image based on image data generated by the image reading section 1 or supplied from an external device. A primary transfer roller 33 primarily transfers this toner image onto the intermediate transfer belt 30 of the intermediate transfer member 3 . During this time, the conveying roller 5 a conveys the sheet P supplied from the sheet containing portion 42 or the manual feed tray 43 along the sheet conveying path S to the secondary transfer portion 40 . Subsequently, the secondary transfer unit 40 secondarily transfers the toner image that has been primarily transferred onto the intermediate transfer belt 30 onto the sheet P. FIG. The fixing device 41 fixes the toner image, which is secondarily transferred onto the sheet P, onto the sheet P. As shown in FIG. After that, the conveying roller 5b conveys the sheet P and discharges it onto the sheet discharging section 44, thereby completing printing on the sheet P. FIG.

Note that the image forming apparatus A may be a monochrome image forming apparatus.

-Sheet feeder-
Next, the configuration of the sheet feeding device 6 according to the first embodiment will be described.

FIG. 2 is a schematic front view showing the internal structure of the sheet feeding device 6 according to the first embodiment. 3 is a schematic side view of the inside of the sheet feeding device 6 of FIG. 2 as viewed from the upstream side in the feeding direction F of the sheet P. FIG. FIG. 4 is a schematic plan view showing the internal structure of the sheet feeding device 6 of FIG. In FIG. 4 , the two-dot chain line indicates the side edge of the maximum size sheet Pmax that can be supplied by the supply roller 61 .

The sheet feeding device 6 feeds the stacked sheets P (in this embodiment, the sheets P stacked in the sheet cassette 45 of the sheet storage portion 42) to the sheet conveying path S. It includes a roller 61, a separation roller 62, a first biasing member S1, and a holder portion 7 (see FIGS. 2 to 4). The separation roller 62 corresponds to the "separation member" described in the claims. In this embodiment, the sheet conveying path S curves upward (+Z direction) on the downstream side of the supply roller 61 . A drive belt 63 is suspended over the shaft portion 600 of the pickup roller 60 and the shaft portion 64 of the supply roller 61 (see FIGS. 2 to 4). Each component of these sheet feeding devices 6 is housed in a frame 8 . The frame 8 is configured by connecting an upper frame 80 and a lower frame 81 made of synthetic resin or the like, for example. The upper frame 80 includes a side wall 82 and a ceiling portion 83 connected to the upper edge of the side wall 82. The lower frame 81 includes a side wall 84 connected to the side wall 82 of the upper frame 80, a side wall 84 and a bottom portion 85 connected to the lower edge of the portion 84 (see FIGS. 2 and 3). Each configuration of the sheet feeding device 6 will be described below.

The pickup roller 60 pulls out the uppermost sheet Pt among the sheets P stacked in the sheet cassette 45 , and rotates following the rotation of the drive belt 63 caused by the rotation of the supply roller 61 .

The pick-up roller 60 is swingably supported by a roller holder 69 with the shaft portion 64 of the supply roller 61 serving as a swing base end (see FIGS. 2 to 4). The roller holder 69 is biased toward the sheet P by a biasing member 690 . The roller holder 69 is made of synthetic resin or the like, for example.

In this embodiment, the sheet P is urged upward, that is, toward the pickup roller 60 by an urging member (not shown) that urges the lifting plate 46 of the sheet cassette 45 . Therefore, when the pickup roller 60 is swung toward the sheet P by the roller holder 69, the pickup roller 60 comes into contact with the uppermost sheet Pt and pulls out the uppermost sheet Pt.

The supply roller 61 supplies the uppermost sheet Pt picked up by the pickup roller 60 to the sheet conveying path S, and is driven to rotate about the axis .delta.1 through the output shaft 66 by being driven by a motor (not shown). (see Figure 3). A clutch 67 is provided on the base end side of the output shaft 66 to switch the output shaft 66 between a rotating state and a stopped state. A shaft portion 64 of the supply roller 61 is connected to an output shaft 66 by a coupling 68 . Bearings 610 to 613 are fitted onto the shaft portion 64 of the supply roller 61 in order from the supply roller 61 toward the rear. The rocking proximal end side portion of the roller holder 69 is fitted onto the bearing portions 610 and 611 .

The separation roller 62 separates the uppermost sheet Pt pulled out by the pickup roller 60 from the other sheets Po of the sheets P, and is arranged to face the supply roller 61 (FIGS. 2 and 4). 3). The separation roller 62 forms a nip area N with the supply roller 61 and is driven to rotate about the axis δ2 as the supply roller 61 is driven to rotate. The separation roller 62 separates the uppermost sheet Pt from the uppermost sheet Pt by the frictional force generated in the nip region N when one or more other sheets Po are pulled out in tandem with the uppermost sheet Pt by the pickup roller 60 . It is designed to be separated from the sheet Po. Bearings 620 and 621 are fitted onto the shaft 65 of the separation roller 62 in order from the separation roller 62 toward the rear.

The first biasing member S1 biases the supply roller 61 and the separation roller 62 in a direction to bring them into contact with each other. In this embodiment, one end side of the first biasing member S1 is engaged with the shaft portion 64 of the supply roller 61 via a bearing portion 612, which will be described later, and the other end side of the first biasing member S1 will be described later. It is engaged with the shaft portion 65 of the separation roller 62 via the bearing portion 620 (see FIG. 3). The first biasing member S1 is made of, for example, a coil spring. A predetermined nip pressure can be maintained in the nip region N between the supply roller 61 and the separation roller 62 by the first biasing member S1.

FIG. 5 is a schematic perspective view showing the holder part 7. FIG. FIG. 6 is a schematic diagram of the inside of the holder portion 7 of FIG. FIG. 7 is a schematic front view showing the behavior of the holder part 7 of FIG. 6, the illustration of the separation roller support hole 75 in the first wall surface 71 is omitted for convenience of illustration.

The holder portion 7 supports the shaft portion 64 of the supply roller 61 and the shaft portion 65 of the separation roller 62, and is made of synthetic resin or the like, for example. The holder unit 7 reciprocates in a direction D intersecting the supply direction F of the sheet P and the axis δ1 direction of the supply roller 61 (in this embodiment, the +D direction along the +Z direction and the −D direction along the −Z direction). It is movably provided (see FIGS. 2 and 4).

A support rail portion 86 that supports the holder portion 7 so as to reciprocate in the direction D is provided on one side of the holder portion 7 in the direction perpendicular to the direction of the axis δ1 of the supply roller 61 (the Y direction in this embodiment). (see FIGS. 2 and 4). In this embodiment, the support rail portion 86 is composed of an upper support rail portion 87 and a lower support rail portion 88 provided on the side wall 82 of the upper frame 80 and the side wall 84 of the lower frame 81 of the frame 8, respectively. (See Figure 2). Groove portions 76 and 77 slidably fitted to the upper support rail portion 87 and the lower support rail portion 88 are provided on one side portion of the holder portion 7 (see FIGS. 5 and 6). By providing the support rail portion 86 and the groove portions 76 and 77, the holder portion 7 that can reciprocate in the direction D can be easily realized.

In this embodiment, the holder portion 7 includes a pair of first wall surfaces 70 and 71 facing each other in the direction of the axis δ1 of the supply roller 61, and a first wall surface connecting one side edge of the first wall surfaces 70 and 71 to each other. 2 wall surface 72 and a bottom wall portion 73 connecting the edges of the first wall surfaces 70 and 71 and the edge of the second wall surface 72 (see FIGS. 5 and 6). The first wall surfaces 70 and 71 are composed of a first wall surface 70 and a first wall surface 71 that are sequentially arranged rearward from the supply roller 61 (see FIG. 3). A boss 78 protrudes from the bottom wall portion 73 (see FIG. 6).

A supply roller support hole 74 that supports the shaft portion 64 of the supply roller 61 and a separation roller support hole 75 that supports the shaft portion 65 of the separation roller 62 are provided in the first wall surfaces 70 and 71, respectively. (See FIGS. 3, 5 and 6). The shaft portion 64 of the supply roller 61 and the shaft portion 65 of the separation roller 62 are passed through the supply roller support hole 74 and the separation roller support hole 75 in the first wall surfaces 70 and 71, respectively. , 71 and supported by the supply roller support hole 74 and the separation roller support hole 75 . By providing the supply roller support hole 74 and the separation roller support hole 75 in the first wall surfaces 70 and 71 of the holder portion 7, a structure for supporting the shaft portion 64 of the supply roller 61 and the shaft portion 65 of the separation roller 62 can be easily realized. can do.

In this embodiment, the separation roller support holes 75 in each of the first wall surfaces 70 and 71 are long holes extending in the direction D, which is the reciprocating direction of the holder portion 7 (see FIGS. 5 and 6). Accordingly, it is possible to allow the shaft portion 65 of the separation roller 62 to move in the direction D with respect to the shaft portion 64 of the supply roller 61 according to the thickness of the sheet P entering the nip region N.

In this embodiment, the supply roller support holes 74 in the first wall surfaces 70 and 71 respectively support the shaft portion 64 of the supply roller 61 with the bearing portions 612 and 613 (see FIG. 3). Similarly, the separation roller support hole 75 in each of the first wall surfaces 70 and 71 supports the shaft portion 65 of the separation roller 62 with bearing portions 620 and 621 . As a result, the bearings 612, 613 and the bearings 620, 621 reduce the wear of the holder 7 due to the rotation of the supply roller 61 and the separation roller 62, so that the reliability of the holder 7 can be improved.

In the present embodiment, the holder portion 7 is arranged outside the maximum size sheet Pmax that can be supplied by the supply roller 61 in the direction of the axis δ1 of the supply roller 61 (see FIG. 4). As a result, even when the sheet Pmax of the maximum size that can be supplied by the supply roller 61 enters the nip area N, the situation in which the holder portion 7 interferes with the sheet P can be avoided.

As described above, the shaft portion 64 of the supply roller 61 and the shaft portion 65 of the separation roller 62 are supported by the holder portion 7 provided so as to be able to reciprocate in the direction D. As shown in FIG. It can be said that the holder portion 7 supports the shaft portion 64 of the supply roller 61 and the shaft portion 65 of the separation roller 62 so as to be integrally reciprocable in the direction D. As shown in FIG. That is, the supply roller 61 and the separation roller 62 are provided so as to be integrally reciprocable in the direction D. As shown in FIG. The supply roller 61 and the separation roller 62 are not separated from each other. For example, when the separation roller 62 moves in the −D direction (or +D direction), the supply roller 61 follows the separation roller 62 and direction) and vice versa. Therefore, the separation roller 62 is not pulled away from the supply roller 61 by the sheet P that has entered the nip area N, and the nip pressure in the nip area N between the supply roller 61 and the separation roller 62 is maintained. As a result, the sheet P can be reliably sandwiched between the supply roller 61 and the separation roller 62, and thus the sheet P can be sent out stably.

In particular, when the sheet conveying path S is curved on the downstream side of the supply roller 61, the above effects of the present invention are more beneficial. As in the example shown in FIG. 7, when the sheet conveying path S curves upward (+Z direction) on the downstream side of the supply roller 61 as in the present embodiment, the sheet P entering the nip region N is supplied. It inevitably curves along the direction of curvature of the sheet conveying path S on the downstream side of the roller 61 . The curved sheet P presses the separation roller 62 positioned on the base end side of the curve of the sheet P in the opposite direction (−Z direction) to the direction of curvature of the sheet conveying path S, that is, in the direction of separating from the supply roller 61 [ Arrow (1) shown in FIG. 7]. If the sheet P is a highly rigid sheet such as thick paper, the pressing force of the sheet P against the separation roller 62 may reach a level sufficient to separate the separation roller 62 from the supply roller 61 . Even in such a case, since the supply roller 61 and the separation roller 62 move integrally in the -D direction [arrow (2) in FIG. 7], the separation roller 62 is pulled away from the supply roller 61. is avoided. As a result, even if the sheet P has high rigidity, the sheet P can be sent out stably. Even if the sheet conveying path S is curved downward (−Z direction) on the downstream side of the supply roller 61, the curved sheet P may move the supply roller 61 in the curved direction of the sheet conveying path S. , that is, in the direction of separating from the separation roller 62, the effect of the present invention is still more beneficial as described above.

In addition, in this embodiment, the holder part 7 has a second biasing member S2 that biases the holder part 7 in a direction (+D direction along the +Z direction in this embodiment) to return the holder part 7 to a predetermined position. (See Figure 3). The second biasing member S2 is made of, for example, a coil spring. The predetermined position of the holder portion 7 refers to the position of the holder portion 7 in the direction D when the nip region N between the supply roller 61 and the separation roller 62 is at a position where the sheet P can be received. A predetermined position of the holder part 7 has an allowable width of about 10 mm, for example.

In this embodiment, the second biasing member S2 is provided outside the holder portion 7 . One end of the second biasing member S2 is locked inside the bottom portion 85 of the lower frame 81 of the frame 8 . The other end of the second biasing member S2 is locked to a boss 78 of the bottom wall portion 73 (see FIG. 6). By locking the second biasing member S2 to the bottom wall portion 73 of the holder portion 7, the second biasing member S2 can be easily provided outside the holder portion 7 using the structure of the holder portion 7. .

Even if the holder portion 7 moves as a result of the sheet P entering the nip region N pressing the separation roller 62 away from the supply roller 61 due to the urging of the second urging member S2, the sheet does not move. After P has passed through the nip region N, the holder part 7 returns to a predetermined position. That is, the nip region N between the supply roller 61 and the separation roller 62 becomes a position where the sheet P can be received when the sheet P enters the nip region N due to the biasing of the second biasing member S2. As a result, even when the separation roller 62 is pressed by the sheet P, the sheet P can be reliably sandwiched between the supply roller 61 and the separation roller 62, and the sheet P can be sent stably. be able to.

Further, in this embodiment, on the opposite side of the holder portion 7 to the second biasing member S2, a holder in the biasing direction of the second biasing member S2 (+D direction along the +Z direction in this embodiment) is provided. A movement restricting portion 89 that restricts movement of the portion 7 is provided (see FIG. 3). Specifically, the movement restricting portion 89 is provided inside the ceiling portion 83 of the upper frame 80 of the frame 8 so as to be able to come into contact with the upper edge of the holder portion 7 . Excessive movement of the holder portion 7 in the biasing direction of the second biasing member S2 is restricted by providing the movement restricting portion 89 on the opposite side of the holder portion 7 with respect to the second biasing member S2. Therefore, when the holder portion 7 is returned to the predetermined position by the biasing force of the second biasing member S2, the position of the holder portion 7 can be stabilized. The position of region N can be stabilized.

The supply roller 61 and the separation roller 62 can be integrally reciprocated in the direction D by the holder portion 7 described above.

Note that the sheet feeding device 6 described above is used for feeding the sheet P from the sheet cassette 45 of the sheet accommodating portion 42 to the sheet conveying path S, and is also used for feeding the sheet P from the automatic document processing device 12 to the document reading device 10, or , feeding out the sheet P from the manual feed tray 43 to the sheet conveying path S.

Further, in the sheet feeding device 6, a separation member such as a separation pad may be used to separate the uppermost sheet Pt from the other sheets Po.

(Embodiment 2)
Only the points of the second embodiment that differ from the first embodiment will be described below.

In Embodiment 2, the elastic force of the first biasing member S1 is greater than the elastic force of the second biasing member S2. Thereby, a predetermined nip pressure can be reliably maintained in the nip area N between the supply roller 61 and the separation roller 62 . That is, it is as follows. When the sheet P that has entered the nip region N presses the separation roller 62 in the direction of pulling it away from the supply roller 61 (the −Z direction in this embodiment), an elastic force acts on the first biasing member S1 in the +D direction. In addition, the holder portion 7 that supports the shaft portion 64 of the supply roller 61 and the shaft portion 65 of the separation roller 62 moves in the -D direction due to the pressure that the separation roller 62 receives from the sheet P. As shown in FIG. Due to the movement of the holder portion 7 in the -D direction, an elastic force acts on the second biasing member S2 in the +D direction. At this time, if the elastic force of the first biasing member S1 is smaller than the elastic force of the second biasing member S2, the separation roller 62 is brought into contact with the supply roller 61 in the +D direction and the nip region N is closed. is formed, the elastic force of the second biasing member S2 in the +D direction is mainly used. There is a risk that it will not. In this regard, by making the elastic force of the first urging member S1 larger than that of the second urging member S2, the separation roller 62 is brought into contact with the supply roller 61 in the +D direction, and the nip region N is widened. When forming, a predetermined nip pressure can be reliably maintained in the nip region N by mainly utilizing the elastic force in the +D direction by the first biasing member S1.

The above-described embodiments and examples are illustrative in all respects and are not grounds for restrictive interpretation. Therefore, the technical scope of the present invention is not to be construed solely by the above-described embodiments and examples, but is defined based on the claims. In addition, all changes within the meaning and range of equivalents to the claims are included.

A image forming apparatus B image forming apparatus main body 6 sheet supply device 60 pickup roller 61 supply rollers 610 to 613 bearing portion 62 separation rollers 620 and 621 bearing portion 621 bearing portion 63 drive belt 64 shaft portion 65 shaft portion 7 holder portions 70 and 71 First wall surface 72 Second wall surface 73 Bottom wall portion 74 Supply roller support hole 75 Separation roller support holes 76, 77 Groove portion 78 Boss 8 Frame 80 Upper frame 81 Lower frame 86 Support rail portion 89 Movement restriction portion D Direction (of holder portion 7 reciprocating direction)
F Supply direction N Nip area P Sheet S Sheet conveying path S1 First biasing member S2 Second biasing member δ1 Axis δ2 Axis

Claims (14)

a pickup roller for pulling out the uppermost sheet among the stacked sheets;
a supply roller that supplies the uppermost sheet picked up by the pickup roller to a sheet conveying path;
a separating member arranged opposite to the feeding roller and separating the uppermost sheet pulled out by the pickup roller from other sheets, the sheet feeding device comprising:
The sheet feeding apparatus, wherein the feeding roller and the separating member are integrally reciprocable in a direction intersecting the feeding direction of the sheet and the axial direction of the feeding roller. The sheet feeding device according to claim 1,
The sheet feeding device, wherein the sheet conveying path is curved on the downstream side of the feeding roller. The sheet feeding device according to claim 1 or 2,
A sheet feeding apparatus, further comprising a first biasing member that biases the supply roller and the separation member in a direction to bring them into contact with each other. The sheet feeding device according to any one of claims 1 to 3,
the separation member is a separation roller,
A sheet, further comprising: a holder portion that is reciprocally movable in a direction intersecting the sheet supply direction and the axial direction of the supply roller and supports the shaft portion of the supply roller and the shaft portion of the separation roller. feeding device. The sheet feeding device according to claim 4,
The sheet feeding device, wherein the holder section has a second biasing member that biases the holder section in a direction to return the holder section to a predetermined position. The sheet feeding device according to claim 3,
the separation member is a separation roller,
further comprising a holder portion reciprocatingly movable in a direction crossing the sheet supply direction and the axial direction of the supply roller and supporting the shaft portion of the supply roller and the shaft portion of the separation roller;
The holder section has a second biasing member that biases the holder section in a direction to return to a predetermined position,
The sheet feeding device, wherein the elastic force of the first biasing member is greater than the elastic force of the second biasing member. The sheet feeding device according to claim 5 or 6,
The second biasing member is provided outside the holder,
A seat characterized in that a movement restricting portion that restricts movement of the holder portion in an urging direction of the second urging member is provided on the opposite side of the holder portion with respect to the second urging member. feeding device. The sheet feeding device according to any one of claims 4 to 7,
The holder portion includes a pair of first wall surfaces facing each other in the axial direction of the supply roller, and a second wall surface connecting one side edge of the pair of first wall surfaces to each other. ,
The pair of first wall surfaces are provided with a supply roller support hole that supports the shaft of the supply roller and a separation roller support hole that supports the shaft of the separation roller. sheet feeding device. The sheet feeding device according to any one of claims 5 to 7,
The holder portion includes a pair of first wall surfaces facing each other in the axial direction of the supply roller, a second wall surface connecting one side edge of the pair of first wall surfaces to each other, and a pair of first wall surfaces. a bottom wall portion that connects the edge of the wall surface and the edge of the second wall surface to each other,
The pair of first wall surfaces are provided with a supply roller support hole that supports the shaft of the supply roller and a separation roller support hole that supports the shaft of the separation roller,
The sheet feeding device, wherein the second biasing member is engaged with the bottom wall portion. The sheet feeding device according to claim 8 or 9,
The sheet feeding device, wherein the separation roller support hole is an elongated hole extending in the reciprocating direction of the holder portion. The sheet feeding device according to any one of claims 8 to 10,
Bearing portions are fitted to the shaft portion of the supply roller and the shaft portion of the separation roller, respectively,
The supply roller support hole supports the shaft portion of the supply roller with the bearing portion of the shaft portion,
The sheet feeding device, wherein the separation roller support hole supports the shaft portion of the separation roller by the bearing portion of the shaft portion. The sheet feeding device according to any one of claims 4 to 11,
The sheet supply device, wherein the holder portion is arranged outside the sheet of the maximum size that the supply roller can supply in the axial direction of the supply roller. The sheet feeding device according to any one of claims 4 to 12,
A support rail portion for supporting the holder portion is provided on one side of the holder portion in a direction orthogonal to the axial direction of the supply roller,
A sheet feeding device, wherein a groove portion slidably fitted to the support rail portion is provided on one side portion of the holder portion. An image forming apparatus comprising the sheet feeding device according to any one of claims 1 to 13.

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