JP2019116368A - Sheet feeding device and image forming device - Google Patents

Abstract

To solve the problem that a sheet fed from a manual feeding part is caught in a gap between a manual feeding path and a return claw.SOLUTION: A movable moving member for guiding a sheet fed by a second feeding member is movable between a separation position away from a first conveyance path and a guide position for guiding a sheet fed by the second feeding member from the separation position toward the first conveyance path to a separation nip part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sheet feeding apparatus and an image forming apparatus.

  2. Description of the Related Art As an image forming apparatus, in addition to a cassette feeding unit that feeds sheets stacked in a feeding cassette, a configuration is known that includes a manual feeding unit that manually feeds sheets according to usage. As such a configuration, there is known a configuration in which the transport path of the sheet fed by the manual feeding portion merges with the transport path of the sheet fed by the cassette feeding portion.

  Patent Document 1 discloses a configuration in which a conveyance path for manual feeding is provided above the feeding cassette. According to Patent Document 1, in a configuration in which the conveyance path from the cassette feeding unit and the conveyance path from the manual feeding unit merge, sheets in the cassette feeding unit are picked up by the sheet conveyed from the manual feeding unit. Discloses a configuration in which a return claw is provided to prevent

JP, 2016-222439, A

  However, in the configuration of Patent Document 1, there is a possibility that the sheet fed from the feeding path of the manual feeding is caught in the gap between the manual feeding path and the return claw.

  An object of the present invention is to prevent a sheet fed from a manual feeding portion from being caught in a gap between a manual feeding path and a return claw, and to reliably deliver the sheet.

  A representative configuration of the present invention for achieving the above object is a loading unit on which a sheet is loaded, a first feeding member for feeding a sheet loaded on the loading unit, and the first feeding member. A separating member is disposed downstream of the first feeding member in the sheet feeding direction by the feeding member, and forms a separation nip portion together with the conveyance member for conveying the sheet, and the conveyance member, and the sheet in the separation nip portion , And a second feeding member provided above the loading portion for feeding sheets and fed by the first feeding member. A sheet feeding apparatus in which a second feeding path of the sheet fed by the second feeding member joins a first feeding path of the feeding sheet, and the sheet is fed by the second feeding member A movable member for guiding the movable seat, and the movable member A separated position separated from the first conveyance path, and a guiding position for guiding a sheet fed by the second feeding member from the separated position toward the first conveyance path to the separation nip portion And is movable between them.

  According to the present invention, it is possible to prevent the sheet fed from the second conveyance path from being caught in the gap between the second conveyance path and the moving member, and to reliably deliver the sheet. is there.

Cross section of image forming apparatus Sectional view of sheet feeding apparatus Sectional view of a sheet feeding apparatus for explaining the positional relationship between a returning member and a moving member A perspective view of a sheet feeding apparatus for explaining the positional relationship between a returning member and a moving member

Example 1
A first embodiment of the present invention will be described using the drawings. Here, a laser beam printer is illustrated as an image forming apparatus. In addition, an image forming apparatus is illustrated in which the toner images of the respective colors on the photosensitive drum are sequentially transferred to the belt, and then the toner images on the belt are collectively transferred to the sheet. However, the dimensions, materials, shapes, etc. of the components described in this embodiment should be changed as appropriate depending on the configuration of the apparatus to which the invention is applied and various conditions. That is, the scope of the present invention is not intended to be limited to the following examples.

<Overall Configuration of Image Forming Apparatus>
An outline of the entire configuration of the image forming apparatus 1 will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of the image forming apparatus 1. The sheet S1 stacked in the feeding cassette 300 is fed by a feeding roller (first feeding member) 311 which rotates clockwise in FIG. The fed sheet S1 is sent to the conveyance nip portion of the conveyance roller 322 and the conveyance opposing roller 321, and is conveyed to a transfer nip portion formed by the opposing roller 202 and the transfer roller 204 as a transfer member.

  Each of the image forming units C111C, C112, C113, and C114 includes at least an image carrier. The photosensitive drums 111, 112, 113, and 114 as image carriers rotate in the counterclockwise direction in the drawing. In each image forming unit, an electrostatic latent image is sequentially formed by the laser beam from the laser scanner 500 on the outer peripheral surface of each photosensitive drum, and then the electrostatic latent image is developed by the developing roller provided in each image forming unit , A toner image is formed. The toner images formed on the photosensitive drums 111, 112, 113, and 114 are transferred to the intermediate transfer belt 201. When forming a color image, toner images of yellow, magenta, cyan, and black are developed on the photosensitive drums 111, 112, 113, and 114, and the toner images formed on each are sequentially transferred to the intermediate transfer belt 130. Ru. Next, the toner images formed on the intermediate transfer belt 130 are collectively transferred onto the sheet S1 sent to the transfer nip portion formed by the opposing roller 202 and the transfer roller 204. The intermediate transfer belt 201 is stretched and rotated by at least the opposite roller 202 and a tension roller.

  Further, the sheet S on which the toner image has been transferred is sent to the fixing nip portion between the fixing film 401 and the pressure roller 402, where it is heated and pressed to fix the toner image on the sheet S1. The sheet S 1 on which the toner image is fixed is discharged to the outside of the image forming apparatus 1 by the discharge roller 403 and the discharge roller 404.

<Structure of feeding device>
The feeding device 2 includes a feeding cassette 300. FIG. 2 is an enlarged sectional view of the vicinity of the feeding nip portion of the feeding device 2. As shown in FIG. 1, the feeding device 2 includes at least a feeding cassette 300 capable of stacking a plurality of sheets, a cassette frame 301, and a swingable sheet support member 302 attached to the cassette frame 301. And Furthermore, the feeding device 2 has a lift arm 303 for lifting the sheet support member 302. The feeding cassette 300 is provided so as to be able to be pulled out and inserted into the apparatus main body from the front side of the apparatus (right side in FIG. 1).

  The sheets stacked in the feeding cassette 300 will be described as a sheet S1 below.

  After the feeding cassette 300 is inserted into the apparatus main body, the drive is transmitted to the lift arm 303, so that the sheet supporting member 302 which is a stacking unit on which the sheet S1 is stacked is rotated about the rotation shaft 304, Rises to a position where it can feed.

  As shown in FIG. 2, a feeding roller 311 is provided as a first feeding member, and the feeding roller 311 is connected to a connecting member 305 which can be rotated in the vertical direction about the axis of the feeding roller 312 as a conveying member. It is supported. The feed roller 311 is movable between a position in contact with the uppermost surface of the sheet S <b> 1 stacked on the sheet support member 302 in the feed cassette 300 and a spaced position.

  When not feeding the sheet S1 from the feeding cassette 300, the feeding roller 311 is retracted upward. When feeding the sheet S1 from the feeding cassette 300, the connecting member 305 rotates to the sheet stacking surface side about the axis of the feed roller 312, and the drive is transmitted to the feed roller 312 and the feeding roller 311. Ru. The feed roller 311 supported by the connecting member 305 abuts on the uppermost surface of the sheet, and the sheet S1 is fed.

  The sheet S1 is fed by the feed roller 311 into the separation nip formed by the feed roller 312 and the separation roller 313, which is a separation member, and the feed roller 311 retracts upward until the next feeding operation is performed. At this time, when only one sheet is fed, the rotational torque is transmitted to the separation roller 313, so the separation roller 313 rotates with the feed roller 312. On the other hand, when two or more sheets are fed by the feeding roller 311, only the frictional force between the sheets is transmitted to the separating roller 313, so the separating roller 313 does not rotate and the second sheet is nipped. Stay on. This allows the sheets to be separated.

  Furthermore, the feeding device 2 has a return claw 315 (first moving member) which is a return member for returning the sheet in the vicinity of the separation nip portion to the upstream side in the feeding direction. The return claw 315 is lower than the first conveying path P1 (conveying path of the sheet S1 fed from the feeding cassette 300 and conveyed near the arrow shown in FIG. 2) fed by the feeding roller 311. It can move to the retracted position 315 (a) (solid line shown in FIG. 2) retracted to the side. The return claw 315 moves from the retracted position 315 (a) to the protruding position 315 (b) (two-dot chain line shown in FIG. 2) protruding to the first conveyance path P1. Move upstream. The return claw 315 prevents the manually fed sheet from picking up the sheet stacked in the feeding cassette 300.

  Next, the configuration and operation of the manual feeding unit will be described. As shown in FIG. 1, a manual conveyance path P <b> 2 (see FIG. 2), which is a second conveyance path, is formed by the lower guide 331 and the upper guide 333. Hereinafter, the sheet conveyed by the manual conveyance path P2 will be referred to as a manual sheet S2.

  At the time of manual feed, the manual feed sheet S2 inserted from the manual feed port 334 (FIG. 1) is conveyed downstream by the manual feed rollers 310a and 311a, which are second feed members. The manual feed sheet S2 conveyed by the manual conveyance rollers 310b, 311b and 310c, 311c is conveyed along the manual conveyance path P2.

  As shown in FIG. 1, a second moving member 332 is provided at the downstream end of the lower guide 331 so as to face the return claw 315. The end of the lower guide 331 is recessed upstream from the end of the upper guide 333 in the feeding direction. A second moving member 332 is provided at the recessed portion (downstream end of the lower guide 331). The second moving member 332 is a movable member that moves by coming into contact with the sheet P2 conveyed in the manual feed path P2.

  As shown in FIG. 2, the movable member 332 is separated from the first conveyance path P1 at a separated position 332 (a) (solid line shown in FIG. 2) and at a guide position 332 (b) (close to the first conveyance path P1). It is provided so as to be movable between the two-dot chain line shown in FIG. The movable member 332 is moved and positioned to the separated position 332 (a) by a pressure spring which is a biasing member (not shown). When the manual feeding unit is not used, that is, when the sheet is fed from the feeding cassette 300, it is located at the separation position 332 (a) and does not interfere with the movement locus 315c of the return claw 315 The position has been determined.

  When the manual feed sheet S <b> 2 is fed from the manual feed portion, the manual feed sheet S <b> 2 abuts on the movable member 332. The movable member 332 moves from the retracted position 332a to the guide position 332 (b) against the biasing force of the pressure spring by being pressed by the manual sheet S2. When the movable member 332 is positioned at the guide position 332 (b), the return claw 315 is also positioned at the projecting position 315 (b), and the movable member 332 contacts the return claw 315. In other words, the movable member 332 is movable between a position (contact position) in contact with the return claw 315 in the guide position and the separated position.

  In the guide position, the movable member 332 is mounted on the return claw 315 so as to overlap the upper side of the return claw 315, and forms a smooth conveyance path without a gap between the movable member 332 and the return claw 315. That is, the movable member 332 is also a guide member for guiding the manual sheet S2 to the separation nip portion. In addition, at the time of manual feeding, the feeding roller 311 retracts upward from the manual feeding path P2 and the separation roller 313 is separated from the feed roller 312, and the manual feeding sheet S2 is manually fed from the manual feeding path P2 to the first feeding path P1. Transport to

  FIG. 3 is a schematic cross-sectional view of the sheet feeding apparatus for explaining the positional relationship between the return claw 315 and the movable member 322. As shown in FIG. In FIG. 3A, the return claw 315 is located at the protruding position, but the movable member 332 (a) is located at the separated position. In this state, when the manual feed sheet S2 is transported to the second transport path P2, the manual feed sheet S2 presses the movable member 332, and the movable member 332 moves. As a result, as shown in FIG. 3B, the movable member 332 is placed on the upper surface of the return claw 315, and the sheet P2 is guided toward the separation nip portion. Here, in order for the movable member 332 to reach the guide position, the return claw 315 may be located at the projecting position, and the movement of the movable member 332 and the return claw 315 may be interlocked.

  FIG. 4 is a perspective view of a part of the sheet feeding device showing the state of FIG. 3 (b). As shown in FIG. 4, a plurality (two in the present embodiment) of the return claws 315 and the movable members 332 are provided in the width direction intersecting the sheet feeding direction. A movable member 332 is provided to correspond to each return claw 315 in the width direction.

  In the first embodiment, the movable member 332 is moved to the separated position 332 (a) by the pressure spring and moved to the guide position 332 (b) by the sheet, but for example, the movable member 332 grasps the sheet position by the sensor. And may be moved by a driving force.

  Further, in the first embodiment, the separation means is the separation roller, but may be a retard system or a pad system.

1 image forming apparatus S1 sheet S2 manual feed sheet P1 first conveyance path P2 second conveyance path 311 feed roller 312 feed roller 313 separation roller 315 return claw 315 (a) retraction position 315 (b) projection position 331 lower guide 332 Movable member 332 (a) separate position 332 (b) guide position

Claims (8)

A loading unit on which sheets are loaded;
A first feeding member for feeding sheets stacked on the loading unit;
A conveying member disposed downstream of the first feeding member in the sheet feeding direction by the first feeding member, for conveying the sheet;
A separation member for forming a separation nip portion together with the transport member, and separating sheets one by one in the separation nip portion;
And a second feeding member provided above the loading unit and feeding a sheet,
A sheet feeding apparatus in which a second conveyance path of a sheet fed by the second feeding member joins a first conveyance path of a sheet fed by the first feeding member,
The sheet fed by the second feeding member is guided, and has a movable moving member, and the moving member is separated from the first conveyance path from the separated position, and from the separated position. 1. A sheet feeding apparatus according to claim 1, wherein the sheet feeding apparatus is movable between a guiding position for guiding the sheet fed by the second feeding member to the separating nip portion by approaching the conveying path.   The sheet feeding apparatus according to claim 1, wherein the moving member is positioned at the separated position by biasing of a biasing member.   An upper guide and a lower guide for forming the second transport path are provided, and the moving member is provided movably with respect to the lower guide at the downstream end side of the lower guide in the feeding direction. The sheet feeding apparatus according to claim 1 or 2, wherein   A return member is provided for returning the sheet in the vicinity of the separation member to the upstream side in the feeding direction by moving from a retracted position retracted from the first conveyance path to a projection position projecting to the first conveyance path. The sheet feeding device according to any one of claims 1 to 3, wherein   5. The sheet feeding apparatus according to claim 4, wherein the separated position of the moving member is a position determined not to interfere with the movement of the return member from the projecting position to the retracted position.   6. The sheet feeding apparatus according to claim 5, wherein the moving member rests on an upper surface of the return member when located at the guide position. An image forming unit for forming a toner image;
An image forming apparatus including a feeding device for feeding a sheet to the image forming unit;
An image forming apparatus, wherein the feeding device is the sheet feeding device according to any one of claims 1 to 6. A loading unit on which sheets are loaded;
A first feeding member for feeding sheets stacked on the loading unit;
A conveying member disposed downstream of the feeding member in the sheet feeding direction by the first feeding member, for conveying the sheet;
A separation member for forming a separation nip portion together with the transport member, and separating sheets one by one in the separation nip portion;
And a second feeding member provided above the loading unit and feeding a sheet,
A sheet feeding apparatus in which a second conveyance path of a sheet fed by the second feeding member joins a first conveyance path of a sheet fed by the first feeding member,
A first movement for moving the sheet in the vicinity of the separating member to the upstream side in the feeding direction by moving from the retracted position retracted from the first conveying path to the projecting position projecting to the first conveying path Members,
A contact position for guiding a sheet fed by the second feeding member and having a movable second moving member, wherein the second moving member is in contact with the first moving member; A sheet feeding device characterized in that it is movable from a contact position to a separated position away from the first moving member.

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