JP2006327753A - Sheet feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve visibility of residual quantity indicating member rotating with interlocking with a bottom plate. <P>SOLUTION: This device includes the bottom plate 30 loading and supporting sheet S to be fed and provided to move up and down according to loading quantity of the sheet S, a rotatable residual quantity indicating member 34 connected to an end part in a paper feeding direction of the bottom plate 30 and indicating residual quantity of the sheet S with interlocking with up and down motion of the bottom plate 30, and an indication window 32a making the residual quantity indicating member 34 visible from an outside of a device body. A thin elastic piece 34a is formed at a visible side tip end of the residual quantity indicating member 34 and an outer surface part of the elastic piece 34a is elastically pressed against an inner wall surface of the device body having the indication window 32a formed thereon. Consequently, the elastic piece 34a is deformed to follow a wall surface shape of the inner wall surface with accompanying rotation of the residual quantity indicating member 34. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet feeding device such as a feeding cassette for feeding a stored sheet.

  In recent years, various apparatuses such as an image forming apparatus that forms an image on a sheet and a reading apparatus that reads an image formed on a document are used as office equipment. Normally, sheets supplied to the image processing apparatus are accommodated in a sheet feeding apparatus such as a feeding cassette or a sheet feeding deck, and are fed one by one by a sheet feeding roller provided on the apparatus main body side for image processing. Done.

  In such a sheet feeding device that is stored in the main body of the image processing apparatus, since the stored sheet is not visible from the outside, the remaining amount of the sheet is unknown. Therefore, there is a case where a remaining amount display device is provided at an exposed portion of the sheet feeding device so that the remaining amount of the stored sheet can be recognized.

  As a conventional sheet feeding device provided with this remaining amount display device, there is one disclosed in Patent Documents 1 to 3. In this conventional sheet feeding apparatus, a bottom plate that stacks and supports the fed sheets and moves up and down according to the stacking amount of the sheets is rotatably disposed. A display window is provided on the surface of the sheet feeding apparatus main body in the sheet feeding direction. Then, one end of a remaining amount display member (arm) supported by the sheet feeding device so as to be rotatable around a fulcrum is disposed so as to be visible from the outside through the display window. The other end is engaged with the end of the bottom plate on the feeding direction side.

In such a sheet feeding device, when the sheet on the bottom plate is consumed and reduced, the bottom plate rises, and the remaining amount display member rotates in conjunction with the rising of the bottom plate, thereby one end of the remaining amount display member. The position of the part in the display window is lowered. Therefore, it is possible to grasp the standard of the remaining sheet capacity by reading the position.
Japanese Utility Model Publication No. 3-113342 (see FIG. 1) Japanese Patent Laid-Open No. 5-32353 (see FIGS. 13 and 15) Japanese Patent Laid-Open No. 10-245139 (see FIGS. 1 and 2)

  However, in the configuration of the sheet feeding device described in Patent Documents 1 to 3, the remaining amount display member rotates around the fulcrum, so that one end of the remaining amount display member moves up and down with a circular arc centered on the fulcrum as a locus. Will do. For this reason, if the display window of the feeding cassette has a cross-sectional shape and is linear, when one end of the remaining amount display member moves up and down, it will be closer to or farther from the display window, causing gaps and shadows. However, there was a problem of poor visibility. Further, when the maximum stacking capacity of sheets increases, this arc tends to increase, and the visibility becomes worse.

  An object of the present invention is made in view of the above-described problems of the prior art, and an object thereof is to improve the visibility of a remaining amount display member that rotates in conjunction with a bottom plate.

  In order to achieve the above object, a sheet feeding apparatus according to the present invention includes a bottom plate that stacks and supports fed sheets and can be moved up and down according to the stacking amount of the sheets, and an end of the bottom plate on the feeding direction side. A rotatable remaining amount display member that is connected to the unit and displays the remaining amount of the sheet in conjunction with the raising and lowering of the bottom plate, and a display window that makes the remaining amount display member visible from the outside of the apparatus main body. The remaining amount display member is formed by forming a thin elastic piece at the front end of the remaining amount display member on the viewing side, and elastically pressing the outer surface of the elastic piece to the inner wall surface of the apparatus main body on which the display window is formed. The elastic piece is deformed so as to follow the shape of the wall surface of the inner wall surface with the rotation.

  Further, the sheet feeding device of the present invention is characterized in that the bottom plate rises as the remaining amount of sheets decreases, and the front end on the viewing side of the remaining amount display member descends.

  According to the present invention, since the outer surface portion of the elastic piece of the remaining amount display member is elastically pressed against the inner wall surface of the front panel, the elastic piece becomes a wall shape of the inner wall surface of the apparatus main body as the remaining amount display member rotates. It will be transformed to follow. For this reason, the visibility of the remaining amount display member in the display window can be improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of an image forming apparatus including a feeding cassette (sheet feeding apparatus) according to the present embodiment. FIG. 2 is a schematic perspective view of the feeding cassette of FIG. In this embodiment, a laser beam printer (hereinafter simply referred to as “printer”) 1 is illustrated as an example of an image forming apparatus. Needless to say, the image forming apparatus can be applied to apparatuses other than a printer, such as a copying machine or a facsimile apparatus.

  First, an outline of the printer 1 will be described. Rollers 4a, 4b, and 4c that convey a sheet S fed from a feeding cassette 2 that can be attached to and detached from the printer 1, and information light D that is based on image information is a photosensitive member that is an electrophotographic photosensitive member of the image forming means 6. The scanner unit 5 for irradiating the drum 6a, the image forming means 6 for forming an image on the photosensitive drum 6a, the transferring means 7 for transferring the image formed on the photosensitive drum 6a to the sheet S, and the transferred image on the sheet S A fixing unit 8 for fixing and a control unit (not shown) are provided.

  The image forming unit 6 includes the above-described photosensitive drum 6 a and at least one process unit, and is unitized as a process cartridge that can be attached to and detached from the printer 1. Examples of the process means include a charging means for charging the photosensitive drum 6a, a developing means for developing a latent image formed on the photosensitive drum 6a, and a cleaning means for cleaning toner remaining on the surface of the photosensitive drum 6a. is there.

  In the printer 1 having such a configuration, the information light D based on the image information is irradiated from the scanner unit 5 to the photosensitive drum 6a, a latent image is formed on the photosensitive drum 6a, and the latent image is developed to develop the photosensitive image. A toner image is formed on the body drum 6a. The printer 1 feeds the sheets S one by one from the feeding cassette 2 by the pick roller 1a in synchronization with the formation of the toner image, and separates and feeds the sheets S one by one by the feed roller 1b and the retard roller 1c. Then, the toner image formed on the photosensitive drum 6 a constituting the image forming unit 6 is transferred onto the sheet S by the transfer unit 7. The transferred sheet S is conveyed to the fixing unit 8 where the transferred toner image is fixed by the fixing unit 8, and is further discharged outside the apparatus by the discharge roller 4c.

  Here, the configuration of the sheet feeding apparatus according to the present embodiment will be specifically described with reference to FIG.

  As shown in FIG. 2, the feeding cassette 2 is rotatable about a fulcrum 30d between the bottom wall 20, a pair of opposing side walls 21, 22 defining the width of the cassette, and both side walls 21, 22. And a bottom plate 30 on which sheets S (not shown) are stacked. A front panel 23 is provided at the end on the rear end side in the mounting direction of the feeding cassette 2. The front panel 23 is supported by a plurality of rib walls 24 extending rearward from a guide wall 27 provided with a plurality of guide ribs 26 for guiding sheet conveyance.

  A separation wall 25 that connects the side wall 21 and the rib wall 24 at a predetermined interval at a substantially right angle is formed on the edge of the one side wall 21 on the front panel 23 side. The separation wall 25 is provided with a rectangular long hole 25a (see FIGS. 4 and 5) extending in the vertical direction. A rectangular display window 23 a extending in the vertical direction is provided at a portion of the front panel 23 that faces the separation wall 25. The front panel 23 has a concave wall 23b having a curved surface that is recessed inwardly when viewed from the outside of the main body of the paper feed cassette 2 at the lower part of the display window 23a.

  An inclined portion 30a having a gentle downward inclination is formed at the downstream end of the bottom plate 30 in the sheet feeding direction. A side wall 21 side side of the inclined portion 30a is provided with a U-shaped surrounding rib 30b projecting to the lower surface side of the bottom plate 30, and a sliding hole 34c extending in the sheet feeding direction inside the surrounding rib 30b. (See FIGS. 4 and 5).

  The remaining amount display member 34 is attached to the rib wall 24 so as to be rotatable (swingable) about a fulcrum 34b. The base end side of the remaining amount display member 34 is inserted into the sheet feeding cassette 2 from the elongated hole 25a of the separation wall 25, and protrudes inward from the side of the bottom plate 30 to the base end portion (see FIG. 4 and FIG. 5, a cylindrical boss 34 c provided integrally in the direction perpendicular to the paper surface from the front surface to the paper surface is slidably engaged with the sliding hole 34 c of the bottom plate 30.

  In addition, a thin elastic piece 34 a is integrally formed at the front end of the remaining amount display member 34 on the viewing side, and the outer surface portion of the elastic piece 34 a is in elastic pressure contact with the inner wall surface of the front panel 23. This elastic piece 34 can be made visible from the outside of the main body of the sheet feeding cassette 2 through a display window 23 a provided on the front panel 23.

  An idler gear 32 is rotatably supported on the front outer surface of one side wall 21. The sector gear 33 meshes with the idler gear 32 and is installed at one end of a bottom plate push-up arm 31 that is rotatably supported by the feeding cassette 2. Are the same. The idler gear 32 and the sector gear 33 constitute drive receiving means for moving the bottom plate 30 up and down. A cover 35 covering the drive receiving means is detachably attached to one side wall 21 with screws 36.

  On the other hand, in the printer 1 main body, a stepping motor (not shown) and a transmission gear (not shown) rotatably supported so as to rotate by this drive are arranged, and the above-mentioned feeding cassette When 2 is attached to the printer 1, the idler gear 32 (drive receiving means) and the transmission gear (drive transmission means) are engaged with each other.

  Further, protrusions 21a and 22a are integrally formed on the outer surfaces of the side walls 21 and 22 so as to extend in the mounting direction of the feeding cassette 2 to the printer. On the other hand, guide rails 9 and 10 attached to the main body of the printer 1 are arranged on both sides of the feeding cassette mounting space opened on the front surface of the main body of the printer 1.

  The printer 1 stops driving the stepping motor (not shown) when the uppermost surface of the sheet S (not shown) is pressed against the pick roller 1a.

  When the feeding cassette 2 is attached to the printer 1, as shown in FIG. 3, the feeding rails 2a and 22a are brought into contact with the guide rails 9 and 10 provided in the printer 1 in the direction of the arrow. Insert the feeding cassette 2.

  When the feeding cassette 2 is attached to the printer 1 in this way, a sensor (not shown) detects that the feeding cassette 2 is attached to the printer 1 and drives a stepping motor (not shown). The drive rotates a transmission gear (not shown), the idler gear 32 meshing with the transmission gear rotates in the direction of the arrow in FIG. 2 (clockwise direction), and the bottom plate push-up arm 31 is rotated by the rotation shaft 31a via the sector gear 33. 4 is rotated as indicated by an arrow A in FIG. 4, and as a result, the bottom plate 30 is rotated around a fulcrum 30d as indicated by an arrow B in FIG.

  In the sheet feeding cassette 2, the bottom plate 30 moves upward as the stacked sheets S are sequentially fed in the direction of the arrow F from the uppermost one, and the remaining plate 34 is integrated therewith. The elastic piece 34a moves downward as indicated by an arrow C in FIG. Further, since the remaining amount display member 34 is attached to the portion of the bottom plate 30 where the displacement is the largest, the change in the stacking height of the sheets S and the amount of movement of the remaining amount display member 34 correspond approximately one to one. Therefore, the stacked state of the sheets S in the main body of the sheet feeding cassette 2 can be directly read by the position of the upper end of the elastic piece 34a in the display window 23a, and the replenishment timing of the sheets S can be known.

  Further, according to the present invention, since the outer surface portion of the elastic piece 34a of the remaining amount display member 34 is elastically pressed against the inner wall surface of the front panel 23, the elastic piece 34a is attached to the front panel as the remaining amount display member 34 rotates. It deform | transforms so that the wall surface shape of the inner wall surface of 23 may follow. For this reason, the visibility of the remaining amount display member 34 in the display window 23a can be improved.

  In other words, when the stacking amount of the sheets S is almost full, as shown in FIG. 4, the elastic pieces 34a are linear and follow the inner shape of the front panel 23. Conversely, the stacking amount of the sheets S is almost empty. When close to each other, as shown in FIG. 5, the elastic piece 34 a freely changes its shape so that the elastic piece 34 a becomes round and conforms to the inner surface shape of the front panel 23, so that the upper end of the elastic piece 34 a is It is possible to always keep away from the display window 23a. Accordingly, the upper end of the elastic piece 34a looks like a bar graph with respect to the display window 23a, so that the visibility is very good.

  In the above-described embodiment, the case where the bottom plate push-up arm is rotated by using a drive source such as a stepping motor and drive transmission means such as a gear to push up the bottom plate has been described. In addition, the bottom plate is disposed on the back side of the bottom plate. A simple bottom plate push-up mechanism using a biasing means such as a spring can also be adopted.

  The present invention can be used in image forming apparatuses such as printers, copiers, and facsimiles.

FIG. 1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. These are the schematic perspective views which show the state which removed the cover which covers the drive reception means of the feeding cassette which concerns on embodiment of this invention. These are the schematic perspective views explaining the operation | movement which mounts the feeding cassette which concerns on the said embodiment to a printer main body. FIG. 6 is a cross-sectional view taken along line xx of the feeding cassette of FIG. 2 when the sheet stacking amount is full. FIG. 6 is a cross-sectional view taken along line xx of the feeding cassette of FIG. 2 when the sheet stacking amount is close to empty.

Explanation of symbols

1 Printer 1a Pick roller 1b Feed roller 1c Retard roller 2 Feed cassette (sheet feeding device)
DESCRIPTION OF SYMBOLS 5 Scanner unit 6 Image formation means 6a Photosensitive drum 7 Transfer means 8 Fixing means 9,10 Guide rail 20 Bottom wall 21 One side wall 22 The other side wall 30 Bottom plate 31 Bottom plate push-up arm 32 Idler gear 33 Sector gear 34 Residual amount display member 34a Elasticity One piece 35 Cover S sheet

Claims (2)

A bottom plate that supports and supports the fed sheets and can be moved up and down according to the amount of stacked sheets, and is connected to an end of the bottom plate on the sheet feeding direction side so that the remaining amount of sheets is interlocked with the raising and lowering of the bottom plate A rotatable remaining amount display member for displaying the display, and a display window for making the remaining amount display member visible from the outside of the apparatus body,
A thin elastic piece is formed at the tip of the remaining amount display member on the visual recognition side, and an outer surface portion of the elastic piece is elastically pressed against an inner wall surface of the apparatus main body on which the display window is formed. The sheet feeding apparatus according to claim 1, wherein the elastic piece is deformed so as to follow the shape of the wall surface of the inner wall surface with the rotation.   The sheet feeding device according to claim 1, wherein the bottom plate rises as the remaining amount of sheets decreases, and the front end on the viewing side of the remaining amount display member descends.

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