JP2005298160A - Sheet feeding device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet feeding device of simple constitution, in which correct residual quantity of sheets can be displayed. <P>SOLUTION: This device comprises a sheet residual quantity display arm 42 composed of a single part comprising a residual quantity display part 42Y, turnably supported on a cassette body 4a in a sheet cassette 4 to be interlocked with a bottom plate 41 to rotate, so that residual quantity of sheets placed on the bottom plate 41 is displayed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet cassette for stacking sheets, which has a sheet remaining amount display for displaying a remaining sheet amount.

  In image forming apparatuses such as printers, copiers, and facsimiles, cut sheets are used as recording paper, and a sheet cassette capable of stacking and storing a plurality of sheets is used. The sheet cassette is provided with a bottom plate that is rotatably supported by the sheet cassette and holds the sheet.

On the other hand, as a method for displaying the remaining amount of sheets stacked on the sheet cassette, a thin and elastically deformable pointer is integrally formed at the tip with respect to a bottom plate rotatably provided on the sheet cassette. A resinous indicator is connected so as to rotate in accordance with the rotation of the bottom plate, and an adjustment dial that engages with the pointer and adjusts the position of the pointer is attached to the indicator so as to be rotatable. The configuration is known (see, for example, Patent Document 1).
JP-A-5-330690

  However, the conventional example has problems such as a complicated structure, adjustment required, and being easily affected by component tolerances.

  Accordingly, the present invention has been made in view of such a current situation, and an object thereof is to provide a sheet feeding apparatus and an image forming apparatus capable of displaying an accurate remaining sheet amount with a simple configuration. .

  In order to achieve the above object, the present invention is capable of storing sheets, a sheet cassette provided detachably on the apparatus main body in a direction perpendicular to the sheet feeding direction, and rotatable on the cassette main body of the sheet cassette. A bottom plate that is supported and on which sheets are stacked, is rotatably supported by the cassette body, one end engages with the bottom plate and interlocks with the bottom plate, and the other end is upstream of the sheet feeding direction from the center of rotation. And a sheet remaining amount display arm having a remaining amount display portion for displaying the remaining amount of sheets stacked on the bottom plate at the other end.

  As described above, according to the present invention, it is possible to provide a sheet feeding apparatus capable of displaying an accurate remaining sheet amount with a simple configuration and an image forming apparatus including the sheet feeding apparatus.

(Embodiment 1)
FIG. 1 is a cross-sectional view illustrating a schematic configuration of a laser beam printer which is an example of an image forming apparatus including a sheet feeding device according to an embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a laser beam printer. The laser beam printer 1 includes an image forming unit 2 that forms an image on a sheet P and a sheet feeding unit that separates and feeds the sheet P to the image forming unit 2 one by one. The apparatus 5 etc. are provided.

  Here, the image forming unit 2 includes a process cartridge 7, a transfer roller 9, and the like that can be attached to and detached from a laser beam printer main body (hereinafter referred to as an apparatus main body) 1. The process cartridge 7 includes a photosensitive drum 8, a charging roller 20, a developing unit 22, a cleaning unit (not shown), and the like. The charging roller 20 is provided in contact with the photosensitive drum 8 so as to be driven to rotate by the photosensitive drum 8. The charging roller 20 uniformly charges the surface of the photosensitive drum when the photosensitive drum 8 rotates. The developing means 22 supplies toner to the developing area of the photosensitive drum 8 to develop the latent image formed on the photosensitive drum 7.

  The sheet feeding device 5 includes a pickup roller 51 serving as a sheet feeding unit, a feed roller 52, a retard roller 53 serving as a sheet separating unit, and a main body in a direction perpendicular to the sheet feeding direction (a direction perpendicular to the paper surface). A detachable sheet cassette 4 is provided. The sheet cassette 4 has a sheet P on which a sheet P is rotatably supported by a cassette body 4a, a sheet remaining amount display arm 42 that rotates in conjunction with the bottom plate 41, a cassette cover 43 that is fixed to the cassette body 4a, and the like. Is provided.

  In the figure, 12 is a laser scanner unit, 10 is a fixing unit, 13 is a sheet discharge roller for discharging the sheet P to the sheet discharge tray 16, 1B is a cassette housing section provided in the apparatus main body 1, and 11 is a control section. It is.

  Next, an image forming operation of the apparatus main body configured as described above will be described.

  When image information is sent from a personal computer (not shown) and a controller board (not shown) that performs image formation processing on this image information generates a print signal, the sheet is detachably mounted on the apparatus body 1 perpendicularly to the sheet feeding direction. The sheets P stacked on the cassette 4 are fed one by one by a pickup roller 51, a feed roller 52, and a retard roller 53, and sent to the nip between the photosensitive drum 8 and the transfer roller 9 in the process cartridge 7.

  On the other hand, based on the image information together with this print command, the laser scanner unit 12 irradiates the photosensitive drum with a bit image of the image information (laser light), and a latent image is formed on the surface of the photosensitive drum 8 according to the bit image. It is formed. Further, by developing this latent image, a toner image is formed on the photosensitive drum.

  The toner image thus formed on the photosensitive drum is then transferred to the sheet P fed into the nip between the photosensitive drum 8 and the transfer roller 9. Further, the sheet P on which the toner image is transferred is sent to the fixing unit 10 and is heated and pressed by the fixing unit 10, whereby the toner image is fixed semipermanently. Thereafter, the sheet P on which the toner image is fixed is discharged to the sheet discharge tray 16 by the discharge roller 13.

  Here, this embodiment will be described in detail.

  2 is a perspective view of the sheet cassette 4 of FIG. 1, and FIG. 3 is a view in which the cassette cover 43 is removed from FIG. FIG. 4 is an enlarged view of an engaging portion between the bottom plate 41 and the remaining sheet amount display arm 42.

  When the sheet cassette 4 is attached to the cassette storage unit 1B, a sensor (not shown) recognizes the attachment of the sheet cassette 4. A lifter mechanism (not shown) installed in the apparatus main body 1 rotates the bottom plate 41 rotatably supported by the sheet cassette 4 to a position where the pickup roller 51 can feed the sheets P stacked on the bottom plate 41. .

  Further, since the pickup roller 51 always feeds at a fixed position, the apparatus is arranged so that the uppermost sheet of the sheet P contacts the pickup roller 51 regardless of the stacking amount of the sheets P stacked on the bottom plate 41. The main body 1 always controls the operation of a lifter mechanism (not shown) by a sensor (not shown). That is, even if the sheets P are sequentially fed by the pickup roller 51 and the number of sheets is reduced, the uppermost sheet of the sheet P is controlled to be in contact with the pickup roller 51 by a lifter mechanism (not shown).

  Next, the remaining sheet amount display arm 42 is one part formed of plastic such as ABS resin, and is rotatably installed in the sheet cassette 4. Further, the engaging portion 42 </ b> X which is one end of the remaining sheet amount display arm 42 is interlocked with the bottom plate 41 by being stuck in the engaging hole 41 </ b> X formed in the bottom plate 41. That is, if the bottom plate 41 rotates, the remaining sheet amount display arm 42 also rotates in conjunction with it.

  Here, if the rotation center of the bottom plate 41 and the rotation center of the remaining sheet amount display arm 42 are positioned coaxially, the distance from the rotation center R to the engagement hole 41X and the engagement portion 42X from the rotation center R. Therefore, the remaining sheet amount display arm 42 smoothly follows the rotation of the bottom plate 41 without requiring a large margin between the remaining sheet amount display arm 42 and the bottom plate 41.

  Further, for example, a triangle mark is engraved on the remaining amount display portion 42Y which is the other end of the remaining sheet amount display arm 42. Contrary to this, a mark 43Y is also engraved on the cassette cover 43. FIG. 5 is a main cross-sectional view showing the position (41a to 41c) of the bottom plate 41 and the position (42a to 42c) of the remaining sheet display arm 42 according to the sheet stacking amount of the sheet cassette 4.

  When there are many sheets stacked on the bottom plate 41, the bottom plate 41 is in the state 41a, and the sheet remaining amount display arm 42 interlocked therewith is in the state 42a. As the remaining amount of sheets stacked on the bottom plate 41 is small or the sheet P is fed by the pickup roller 51 and the number of sheets stacked on the bottom plate 51 decreases, the bottom plate 41 is 41a → 41b → 41c, and the remaining sheet display arm is 42a → 42b → 42c. That is, the position where the remaining amount display portion 42Y indicates the mark 43Y changes depending on the remaining amount of sheets stacked on the sheet cassette 4, and the user who uses the apparatus main body 1 knows the sheet stacking amount of the sheet cassette 4. be able to.

  Further, since the sheet remaining amount display arm 42 is a single component, the accuracy of the sheet remaining amount display of the sheet cassette 4 is determined only by the positions of the engaging portion 42X and the remaining amount display portion 42Y. That is, when the sheet remaining amount display arm 42 is manufactured, the correct remaining amount can be displayed as long as these two positions are correctly formed.

  Thus, by forming the sheet remaining amount display arm 42 that rotates in conjunction with the bottom plate 41 with one component, the sheet remaining amount of the sheet cassette 4 can be displayed with an accurate and simple configuration.

Sectional drawing which shows schematic structure of the laser beam printer which is an example of the image forming apparatus provided with the sheet feeding apparatus which concerns on embodiment of this invention The perspective view of the principal part of the sheet cassette 4 of FIG. The figure which removed the sheet cassette cover from the sheet cassette of FIG. FIG. 2 is an enlarged view of an engaging portion between the bottom plate of the sheet cassette and the remaining sheet amount display arm in FIG. Sectional drawing which showed the position of the baseplate according to the sheet | seat loading amount of the sheet cassette of FIG. 2, and a sheet residual amount display arm

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser beam printer 2 Image formation part 4 Sheet cassette 4a Cassette main body 41 Bottom plate 41X Engagement hole 42 Remaining sheet detection arm 42X Engagement part 42Y Remaining amount display part 43 Cassette cover 43Y Mark 5 Sheet feeding device 51 Pickup roller 52 Feed Roller 53 retard roller

Claims (4)

A sheet cassette that can store sheets and is detachably attached to the apparatus body in a direction perpendicular to the sheet feeding direction;
A bottom plate that is rotatably supported by the cassette body of the sheet cassette and on which sheets are stacked;
The cassette body is rotatably supported, one end engages with the bottom plate and interlocks with the bottom plate, the other end is positioned upstream of the rotation center in the sheet feeding direction, and the other end is connected to the bottom plate. A sheet remaining amount display arm having a remaining amount display portion for displaying the remaining amount of stacked sheets;
A sheet feeding apparatus comprising:   The sheet feeding apparatus according to claim 1, wherein a rotation center of the remaining sheet amount display arm is coaxial with a rotation center of the bottom plate.   3. The sheet feeding apparatus according to claim 1, wherein the remaining sheet amount display arm and the remaining amount display unit are configured as a single component. A sheet feeding apparatus according to any one of claims 1 to 3,
An image forming unit that forms an image on the sheet fed from the sheet feeding device;
An image forming apparatus comprising:

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