JP2006089247A - Paper feed cassette - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feed cassette capable of fixing a slidable side guide unit to a desired position with high accuracy and easily performing the slide operation. <P>SOLUTION: A side guide unit 100 is provided slidably in the vertical direction with respect to a slide 110 at a side part of the slider 110 slidable in the direction orthogonal to the paper sheet feeding direction, and a lock member 120 having an engagement projecting part 121 to be engaged/disengaged with/from a bottom side 94 of the paper feed cassette is provided on a lower part thereof. By narrowing the space between the knob parts 112, 122 by picking the knob parts provided respectively on an upper part of the slider 110 and an upper part of the lock member 120 in the direction orthogonal to the paper sheet feeding direction, the lock member 120 is vertically moved to disengage the engagement projecting part 121 from the bottom part 94 of the paper feed cassette to allow the side guide unit 100 to slide. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a paper feed cassette used in an image forming apparatus such as a printer, a facsimile machine, and a copying machine.

2. Description of the Related Art Conventionally, a paper feed cassette having a side guide unit that is slidably attached to the bottom surface of a paper feed cassette in a direction orthogonal to the paper feed direction and that can be locked at a position corresponding to the paper size. The guide unit has a separation claw for separating the uppermost sheet to be fed from the next sheet among the sheets stacked in the sheet cassette, and the direction perpendicular to the sheet feeding direction by the rack and pinion. Is configured to be slidable (see, for example, Patent Document 1).
In addition, the lock portion is provided so as to be rotatable with respect to the side guide, and the lock portion is rotated in the sliding direction of the side guide by picking the knobs provided at the upper portion of the lock portion and the upper portion of the side guide. There is also known a paper feed cassette in which the engagement guide at the lower part of the lock part and the engagement part at the bottom of the paper feed cassette are engaged and disengaged so that the side guide can be fixed at a predetermined position (for example, Patent Documents). 2).
Also known is a lock member provided in a direction orthogonal to the slider slide direction and a lock member provided so as to be rotatable in a direction orthogonal to the slider slide direction (see, for example, Patent Documents 3 and 4).
JP 2003-252472 A Japanese Unexamined Patent Publication No. 08-198458 JP 2001-206557 A JP 2004-91066 A

In the paper feed cassette described in Patent Document 1 described above, the side guide unit is configured to be slidable in a direction orthogonal to the paper feeding direction by a rack and a pinion, so the side guide unit corresponds to the paper size. Even if an attempt is made to fix the position of the side guide unit to the desired position, the side guide unit cannot be accurately fixed to the desired position due to backlash between the rack and the pinion.
For this reason, there is a problem that the positional accuracy of the sheet guided by the side guide unit with respect to the separation claw is lowered, and the sheet separation failure (resulting in sheet double feeding) is likely to occur.
On the other hand, if the configuration described in Patent Document 2, that is, the side guide is fixed by providing the lock portion rotatably with respect to the side guide and engaging the lock member with the cassette bottom portion, The problem seems to be solved.
However, the device described in Patent Document 2 is configured to engage and disengage the engaging convex portion at the lower portion of the locking portion and the engaging portion at the bottom portion of the sheet feeding cassette by rotating the locking portion in the sliding direction of the side guide. Therefore, a gap is required between the lock member side engaging portion and the cassette bottom side engaging portion to enable the rotation of the lock member.
Therefore, rattling occurs between the bottom of the sheet feeding cassette and the side guide by this gap, and the above problem cannot be solved.
On the other hand, in the thing of the said patent document 3 or 4, since the lock member turns into the orthogonal | vertical direction with the sliding direction of a slider, it seems that said problem can be solved.
However, since the picking direction when the lock member is rotated and the direction in which the guide is slid are orthogonal, it is difficult to perform an operation of sliding the guide while picking the knob.
An object of the present invention is to solve the above-described problems, and to provide a paper feeding cassette that can fix a slidable side guide unit at a desired position with high accuracy and that can be easily slid.

In order to achieve the above object, the paper feed cassette according to the present invention is slidably attached to the bottom surface of the paper feed cassette in a direction perpendicular to the paper feeding direction and can be locked at a position corresponding to the paper size. A paper cassette with a unit,
The side guide unit is
A separation claw for separating the uppermost sheet of the sheets stacked in the sheet cassette from the next sheet;
A slider that can slide in a direction perpendicular to the paper feeding direction;
A locking member provided at the side of the slider so as to be slidable in the vertical direction with respect to the slider, and provided at the lower part with an engaging convex part that engages and disengages from the bottom surface of the paper feed cassette;
Knob portions provided on the upper portion of the slider and the upper portion of the lock member in a direction orthogonal to the paper feeding direction, respectively, and by picking these pick portions and narrowing the interval between the two pick portions, A knob that moves the member upward to release the engagement between the engaging projection and the bottom of the sheet cassette, and allows the slider to slide;
It is characterized by having.
According to such a configuration, the engagement convex portion provided at the lower portion of the lock member provided to be slidable in the vertical direction with respect to the slider on the side portion of the slider is engaged with the bottom surface of the paper feed cassette. The side guide unit can be fixed at a position corresponding to the paper size.
Then, when the lock member slides up and down, the engaging convex portion and the bottom surface of the sheet feeding cassette are engaged and disengaged, so that the lock member is inserted between the lock member side engaging portion and the cassette bottom side engaging portion. It is not necessary to provide a gap for enabling rotation.
Accordingly, it is possible to eliminate rattling between the bottom of the sheet feeding cassette and the side guide unit by the amount that does not require the clearance, and the slidable side guide unit is accurately fixed at a desired position. Is possible.
As a result, it is possible to improve the positional accuracy of the paper guided by the side guide unit with respect to the separation claw, and to prevent paper separation failure (resulting in paper double feeding).
The knobs are provided on the upper part of the slider and the upper part of the lock member in the direction orthogonal to the paper feeding direction (and hence the slider sliding direction). By narrowing the interval, the lock member is moved upward to disengage the engagement convex portion from the paper feed cassette bottom, and the slider can be slid. The direction of picking when sliding upward is the same as the direction of sliding the side guide unit.
Therefore, the operation of sliding the side guide unit while picking the knob becomes easy.
As described above, according to the present invention, the slidable side guide unit can be fixed to a desired position with high accuracy, and a sliding operation can be easily performed.

Hereinafter, embodiments of a paper feed cassette according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic front view showing an internal structure of an example of an image forming apparatus using an embodiment of a paper feed cassette according to the present invention.
This image forming apparatus is a color image forming apparatus capable of longitudinally feeding A4 size paper (including letter size) to form a full color image on both sides thereof. The image forming apparatus is accommodated in a case 11 and the case 11. , An image carrier unit 20, an exposure unit 30 as an exposure unit, a developing unit (developing device) 40 as a developing unit, an intermediate transfer unit 50, and a fixing unit (fixing unit) 60 as a fixing unit. I have.
The case 11 is provided with a frame (not shown) of the apparatus main body 10, and each unit is attached to the frame.

  The image carrier unit 20 includes a photoconductor 21 having a photosensitive layer on the outer peripheral surface, and a corona charger (scorotron charger) 22 as a charging unit that uniformly charges the outer peripheral surface of the photoconductor 21. The outer peripheral surface of the photoconductor 21 uniformly charged by the corona charger 22 is selectively exposed with the laser light L from the exposure unit 30 to form an electrostatic latent image. The developer 40 is applied with a toner as a developer to form a visible image (toner image). This toner image is primarily transferred to the intermediate transfer belt 51 of the intermediate transfer body unit 50 by the primary transfer portion T1, and further to the second image. The secondary transfer unit T2 performs secondary transfer onto a sheet to be transferred.

In the case 11, a conveyance path 16 that conveys a sheet on which an image is formed on one side by the secondary transfer portion T <b> 2 toward a sheet discharge portion (discharge tray) 15 on the top surface of the case 11, and the conveyance path 16. A return path 17 is provided for switching back the sheet conveyed toward the sheet discharge unit 15 and returning it to the secondary transfer unit T2 so as to form an image on the other side.
Reference numeral 70 denotes a duplex unit configured to be detachable from the apparatus main body, and the return path 17 is completed by mounting the duplex unit 70.
Under the case 11, a paper feed cassette 18 is provided for stacking and holding a plurality of sheets, and a paper feed roller 19 for feeding the sheets one by one toward the secondary transfer portion T2. ing.

  Below the duplex unit 70, there is provided a multi-purpose tray 81 that forms a manual paper feed unit 80. A paper feed roller 82 that feeds the sheets set on the multi-purpose tray 81 one by one is provided in the main body of the apparatus. Is provided.

  The developing device 40 is a rotary developing device (rotary developing device), and a developing device cartridge (not shown) for each color in which yellow toner, cyan toner, magenta toner, and black toner are accommodated with respect to the rotating body main body 41. It is detachably attached. As the rotating body 41 rotates at 90 ° pitch in the direction of arrow R, the developing roller (not shown) provided in each developing device cartridge is selectively brought into contact with the photosensitive member 21, and the surface of the photosensitive member 21. Can be selectively developed.

The exposure unit 30 irradiates the laser 21 with the laser light L.
The intermediate transfer unit 50 includes a unit frame (not shown), a drive roller 54 rotatably supported by the frame, and the intermediate transfer belt 51 stretched around a plurality of driven rollers. The intermediate transfer belt 51 is circulated and driven in the direction of the arrow shown in the figure. The primary transfer portion T1 is formed at the contact portion between the photosensitive member 21 and the intermediate transfer belt 51, and the secondary transfer portion T2 at the pressure contact portion between the driving roller and the secondary transfer roller 10b provided on the main body side. Is formed.
The secondary transfer roller 10b can be brought into contact with and separated from the drive roller 54 (and therefore with respect to the intermediate transfer belt 51), and when it comes into contact, a secondary transfer portion T2 is formed.
Accordingly, when forming a color image, a plurality of color toner images are superimposed on the intermediate transfer belt 51 while the secondary transfer roller 10b is separated from the intermediate transfer belt 51, and then a color image is formed. The secondary transfer roller 10b contacts the intermediate transfer belt 51, and the sheet is supplied to the contact portion (secondary transfer portion T2), whereby a color image (toner image) is formed on the sheet from the intermediate transfer belt 51. Transfer (secondary transfer) is performed.
The sheet on which the toner image has been transferred passes through the fixing unit 60 to melt and fix the toner image, and is discharged toward the paper discharge tray 15.

The sheet feeding to the image forming unit is selectively performed from one of the sheet feeding cassette 18 and the manual sheet feeding unit 80 described above.
Normally, plain paper or the like is normally set in the paper feed cassette 18, but various papers are set in the multi-purpose tray 81 as necessary. In other words, plain paper, cardboard, postcards, envelopes, OHP sheets, and other recording materials are appropriately set in the multi-purpose tray 81 as required by the user.

2A and 2B are views showing the paper feed cassette 18, wherein FIG. 2A is a plan view and FIG. 2B is a cross-sectional view taken along line bb in FIG. 2A shows a state in which the plane of FIG. 1 is rotated 90 degrees counterclockwise.
FIG. 3 is a partially enlarged view of FIG.
As shown in FIGS. 1 and 2, the paper feed cassette 18 includes a substantially box-shaped cassette body 90 in which sheets to be fed (not shown) are stored in a stacked state, and a shaft inside the cassette body 90. 91 (see FIG. 1) is attached so as to be slidable in a direction perpendicular to the paper feeding direction (direction of arrow F in FIG. 2 (a)) with respect to the push-up plate 92 mounted rotatably and the bottom surface 94 of the paper feed cassette. And a pair of side guide units 100L and 100R that can be locked at positions corresponding to the paper size.
Hereinafter, the pair of side guide units 100L and 100R will be described, but members and parts common to or corresponding to both units will be described by omitting the symbols L and R unless otherwise required.

The side guide unit 100 is engaged with both corners of the leading edge of the uppermost sheet fed by the push-up plate 92 and fed by the paper feed roller 19 (direction of arrow F in FIG. 2A). A separation claw 93 for separating the uppermost sheet from the next sheet by being bent at both corners of the uppermost sheet, and a slider 110 slidable in a direction orthogonal to the sheet feeding direction are provided. Yes.
Racks 115L and R are formed on the sliders 110L and R, respectively, and these racks 115L and R mesh with a common pinion 95.
Therefore, when one slider 110 (and therefore the side guide unit 100) is slid, the other slider 110 is also slid by the same amount as the sliding amount.
A guide rail portion (not shown) for guiding the slide of the side guide unit 100 is provided on the bottom surface 94 of the paper feed cassette.
The inner surface 116 of the slider 110 constitutes a guide surface that abuts the side edge of the fed paper and guides the paper.

As shown in FIG. 3, the one side guide unit 100R is provided on the outer side of the slider 110R so as to be slidable in the vertical direction with respect to the slider 110R. The locking member 120 provided with the engaging convex part 121 to be provided is provided.
At the upper part of the slider 110 and the upper part of the lock member 120, knobs 112 and 122 are respectively provided outward in the direction orthogonal to the sheet feeding direction (left and right direction in FIG. 3). The lock member 120 is moved upward to release the engagement between the engaging convex portion 121 and the sheet feeding cassette bottom portion 94 by narrowing the gap between the two picking portions, and the slider 110 (and thus the side guide unit) is released. 100R) can be slid.

The slider 110 includes a sheet metal member 111 having an L-shape when viewed from the front, and a guide member 113 provided integrally on the outer side (right side in FIG. 3) of the sheet metal member 111. The sheet metal member 111, the guide member 113, In between, the lock member 120 is provided to be slidable in the vertical direction.
The guide member 113 is provided with a spring hook 114, and the lock member 120 is also provided with a spring hook 124, and a tension spring 130 is stretched around these spring hooks.
Therefore, the lock member 120 is always urged downward by the tension spring 130, but when the knobs 112 and 122 are picked up, the lock member 120 moves upward against the urging force of the tension spring 130, The engagement with the paper feed cassette bottom 94 is released.

A plurality of engagement recesses 94a that can be engaged with and disengaged from the engagement protrusions 121 are provided on the sheet feed cassette bottom surface 94 at positions corresponding to the sheet size along the sliding direction of the side guide unit 100R.
Therefore, the knobs 112 and 122 are picked, the engagement between the engagement convex part 121 and the engagement concave part 94a is released, the side guide unit 100R is slid, and one side edge of the paper stored in the paper feed cassette 18 is formed. The side guide unit 100R is fixed at the position by opening the knobs 112 and 122 at the combined positions and engaging the engaging convex portions 121 and the engaging concave portions 94a. At the same time, when the side guide unit 100R is slid by the rack and pinion mechanism described above, the other side guide unit 100L is also slid, and when the side guide unit 100R is fixed, the other side guide unit 100L is also moved to the other side edge of the sheet. It will be fixed in the matching position.

The sheet feeding cassette 18 as described above is slidably attached to the bottom surface 94 of the sheet feeding cassette 18 in a direction orthogonal to the sheet feeding direction F and can be locked at a position corresponding to the sheet size. A paper cassette with
The side guide unit 100R is
A separation claw 93 for separating the uppermost sheet to be fed out of the sheets stacked in the sheet feeding cassette 18;
A slider 110 slidable in a direction orthogonal to the paper feeding direction F;
A locking member 120 provided on the side of the slider 110 so as to be slidable in the vertical direction with respect to the slider 110, and provided at the lower part with an engaging convex portion 121 that engages and disengages from the bottom surface 94 of the paper feed cassette;
Knob portions 112 and 122 provided respectively in the upper direction of the slider 110 and the upper portion of the lock member 120 in a direction orthogonal to the paper feeding direction F. By narrowing, the lock member 120 is moved upward to release the engagement between the engagement convex portion 121 and the paper feed cassette bottom portion 94, and the knobs 112 and 122 that allow the slider 110 to slide are provided. Therefore, according to the paper feed cassette 18, the following operational effects can be obtained.

That is, the side guide is engaged by engaging the engagement convex portion 121 provided at the lower portion of the lock member provided to be slidable in the vertical direction with respect to the slider 110 at the side portion of the slider 110. The unit 100 can be fixed at a position corresponding to the paper size.
When the lock member 120 slides up and down, the engagement convex portion 121 and the paper feed cassette bottom surface 94 are engaged and disengaged. Therefore, the engagement portion 121 on the lock member 120 side and the engagement portion on the cassette bottom 94 side It is no longer necessary to provide a gap for allowing the lock member 120 to rotate between the switch 94a and the cover 94a.
Accordingly, it is possible to eliminate rattling between the paper feed cassette bottom portion 94 and the side guide unit 100 as much as it is not necessary to provide the gap, and the slidable side guide unit 100 can be accurately placed at a desired position. It can be fixed.
As a result, the positional accuracy of the paper guided by the side guide unit 100 with respect to the separation claw 93 can be improved, and paper separation failure (resulting in paper double feeding) can be prevented.

The knobs 112 and 122 are provided at the upper part of the slider 110 and the upper part of the lock member 120 in the direction orthogonal to the sheet feeding direction (and thus the sliding direction of the slider 100). By narrowing the gap between the two picking parts 122, the locking member 120 is moved upward to release the engagement between the engaging convex part 121 and the paper feed cassette bottom part 94, and the slider 110 is slid. Since it is configured to be possible, the direction in which the lock member 120 is slid upward and the direction in which the side guide unit 100 is slid are the same direction.
Therefore, the operation of sliding the side guide unit 100 while picking the knobs 112 and 122 becomes easy.
As described above, according to the paper feed cassette 18, the slidable side guide unit 100 can be accurately fixed at a desired position, and a sliding operation can be easily performed.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the gist of the present invention.

1 is a schematic front view showing an internal structure of an example of an image forming apparatus using an embodiment of a paper feed cassette according to the present invention. 2A and 2B are views showing the sheet feeding cassette 18, wherein FIG. 1A is a plan view, and FIG. The elements on larger scale of FIG.2 (b).

Explanation of symbols

  18: paper feeding cassette, F: paper feeding direction, 93: separation claw, 94: bottom surface, 100: side guide unit, 110: slider, 112: knob, 120: lock member, 121: engagement convex, 122 : Picking part.

Claims (1)

A paper feed cassette having a side guide unit that is slidably attached to the bottom surface of the paper feed cassette in a direction orthogonal to the paper feed direction and that can be locked at a position corresponding to the paper size.
The side guide unit is
A separation claw for separating the uppermost sheet of the sheets stacked in the sheet cassette from the next sheet;
A slider that can slide in a direction perpendicular to the paper feeding direction;
A locking member provided at the side of the slider so as to be slidable in the vertical direction with respect to the slider, and provided at the lower part with an engaging convex part that engages and disengages from the bottom surface of the paper feed cassette;
Knob portions provided on the upper portion of the slider and the upper portion of the lock member in a direction orthogonal to the paper feeding direction, respectively, and by picking these pick portions and narrowing the interval between the two pick portions, A knob that moves the member upward to release the engagement between the engaging projection and the bottom of the sheet cassette, and allows the slider to slide;
A paper feed cassette characterized by comprising:

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