JP2006089248A - Paper feed cassette - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feed cassette in which an engagement projecting part and an engagement recessed part are hardly broken, and a slidable paper sheet position regulation unit can be fixed to a desired position with high accuracy. <P>SOLUTION: A paper sheet position regulation unit 100R comprises a slider 110 slidably mounted on a bottom side 94 of a paper feed cassette, and a lock member 120 provided slidably on the lower part with respect to the slider 110 in the vertical direction with an engagement projecting part 121 to be engaged/disengaged with/from an engagement recessed part 94a in the bottom side of the paper feed cassette. Both the engagement projecting part 121 and the engagement recessed part 94a are constituted in a square shape when viewed from the direction orthogonal to the sliding direction of the slider 110. <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 paper position restriction unit that is slidably attached to the bottom surface of a paper feed cassette and that can be locked at a position corresponding to the paper size. A slider is slidably attached to the bottom of the cassette, and is provided so as to rotate with respect to the slider, and at the bottom is provided with an engaging projection that engages with and disengages from the engaging recess on the bottom of the sheet feeding cassette. There is known a paper feed cassette that includes a lock member, and each of the engagement convex portion and the engagement concave portion has a triangular shape when viewed from a direction orthogonal to the sliding direction of the slider (for example, (See Patent Documents 1, 2, and 3).
Further, there is also known a paper feeding cassette in which the engaging convex portion and the engaging concave portion are both formed in a square shape when viewed from a direction orthogonal to the sliding direction of the slider (see, for example, Patent Document 4). ).
JP 2001-206557 A JP 2004-91066 A Japanese Unexamined Patent Publication No. 08-198458 JP 2002-255358 A

In the paper feed cassettes described in Patent Documents 1 to 3, the engagement convex portion provided on the lock member and the engagement concave portion provided on the bottom surface of the cassette are both viewed from a direction perpendicular to the sliding direction of the slider. Therefore, when the user accidentally applies a large force to the paper position restriction unit when the user slides the paper position restriction unit, the engagement convex part and / or the engagement concave part are formed. There is a problem that is easily damaged.
Such a problem seems to be solved by the configuration described in Patent Document 4, that is, by making the shape of the engaging protrusion and the engaging recess both square.
However, the configuration described in Patent Document 4 is configured to engage and disengage the engaging convex part at the lower part of the locking part and the engaging concave part at the bottom of the sheet feeding cassette by rotating the lock part in the sliding direction of the paper position regulating unit. Therefore, a gap is required between the lock member side engaging convex portion and the cassette bottom side engaging concave portion so as to enable rotation of the lock member.
Therefore, there is a backlash between the bottom of the sheet feeding cassette and the sheet position regulating unit side by this gap, and another problem arises that the sheet position regulating unit cannot be fixed at a desired position with high accuracy. .
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, the engagement convex portion and the engagement concave portion are not easily damaged, and a paper feed cassette capable of accurately fixing a slidable paper position regulating unit at a desired position. Is to provide.

In order to achieve the above object, the paper feed cassette of the present invention is slidably attached to the bottom surface of the paper feed cassette and is provided with a paper position regulating unit that can be locked at a position corresponding to the paper size. Because
The paper position regulating unit is
A slider slidably attached to the bottom of the paper cassette;
A locking member provided to be slidable in the vertical direction with respect to the slider, and provided with an engaging convex part that engages and disengages with an engaging concave part on the bottom surface of the paper feed cassette at the lower part;
Both the engaging convex portion and the engaging concave portion are formed in a quadrangular shape when viewed from a direction perpendicular to the sliding direction of the slider.
According to such a configuration, the position of the sheet is determined by engaging the engagement protrusion provided at the lower portion of the lock member provided so as to be slidable in the vertical direction with respect to the slider with the engagement recess on the bottom surface of the sheet feeding cassette. The restriction unit can be fixed at a position corresponding to the paper size.
Since both the engaging convex portion and the engaging concave portion are formed in a quadrangular shape when viewed from the direction perpendicular to the sliding direction of the slider, the engaging convex portion and the engaging concave portion are damaged. It becomes difficult.
Further, since the engaging projection and the engaging recess on the bottom surface of the sheet feeding cassette are engaged and disengaged by sliding the locking member up and down, the locking member side engaging projecting portion and the cassette bottom side engaging recess are disposed between. In addition, it is not necessary to provide a gap for enabling the lock member to rotate.
Therefore, it is possible to eliminate rattling between the bottom of the paper feed cassette and the paper position regulating unit as much as it is not necessary to provide the gap, and the slidable paper position regulating unit is accurately fixed at a desired position. It becomes possible to do.
As described above, according to the present invention, the engaging convex portion and the engaging concave portion are not easily damaged, and the slidable paper position regulating unit can be accurately fixed at a desired position.
Preferably, the bottom surface of the engaging convex portion of the lock member is provided with a triangular concave portion when viewed from a direction orthogonal to the sliding direction of the slider, and is provided on the bottom surface of the cassette corresponding to the paper size. Among the engagement recesses, an engagement recess whose interval between adjacent engagement recesses is shorter than the length of the engagement recess in the sliding direction of the slider is formed on the bottom surface of the engagement recess with the triangular shape. Triangular protrusions that engage and disengage from the recesses are provided.
With this configuration, it is possible to fix the paper position regulating unit at a position corresponding to the paper size even for paper of slightly different sizes.

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 as a paper position regulating unit that can be locked at a position 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 is provided with an engaging convex portion 121 that engages and disengages with the concave portion 94a.
Both the engaging convex part 121 and the engaging concave part 94a are formed in a quadrangular shape when viewed from the direction orthogonal to the sliding direction of the slider 110.
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 engagement convex portion 121 and the engagement concave portion 94a of the paper feed cassette bottom portion 94, thereby reducing the slider 110. (Thus, the side guide unit 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 engaging recess 94a of the sheet feeding 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.

Some paper sizes differ only slightly.
For example, the EXE width is only 2 mm (1 mm on one side) different from the B5 size.
In such a case, as described above, if the engaging convex portion 121 and the engaging concave portion 94a are simply formed in a quadrangular shape, it is not possible to cope with such a slight difference in sheet size. In order to cope with such a slight paper size difference, the width or thickness of the engaging convex portion 121 and the engaging concave portion 94a in the paper width direction (the sliding direction of the side guide unit 100) must be reduced. (In the above example, it must be 1 mm or less), because doing so would reduce the strength of the engaging projection 121 or the engaging recess 94a.
On the contrary, if the width or thickness of the engaging convex portion 121 or the engaging concave portion 94a is to be increased in order to ensure the strength, the slight difference in the size of the paper as described above is caused by the adjacent factors. The distance between the mating recesses 94a (see L1 in FIG. 4B) is shorter than the length of the engaging recess in the sliding direction of the slider 110 (see L2 in FIG. 4B). You won't get.
In order to solve this problem, the present embodiment is configured as follows.

4A is a cross-sectional view when the side guide unit 100R is fixed at a position corresponding to EXE size paper, FIG. 4B is a partially enlarged view of FIG. 4A, and FIG. 4C is B5 size paper. Sectional drawing at the time of fixing the side guide unit 100R to the corresponding position, FIG. (D) is the elements on larger scale of FIG. (C).
As shown in these drawings, a triangular concave portion 121a is provided on the bottom surface of the engaging convex portion 121 of the lock member 120 when viewed from a direction orthogonal to the sliding direction of the slider 110.
Further, among the engaging recesses 94a provided on the bottom surface of the cassette corresponding to the sheet size, the interval L1 (1 mm in the above example) between the adjacent engaging recesses is related to the slider sliding direction of the engaging recess 94a. For the engagement recesses that are shorter than the length L2 (for example, 2 mm in this embodiment), these engagement recesses are combined (the combined engagement recess is indicated by reference numeral 94a '). A triangular protrusion 94b that engages with and disengages from the triangular recess 121a is provided on the bottom surface of 94a '.
If comprised in this way, as shown to Fig.4 (a) (b), the engagement convex part 121 of the locking member 120 is engaged with the outer side of engagement concave part 94a ', and the triangular protrusion 94b, and it is EXE size. The side guide unit 100R can be fixed at a position corresponding to the sheet, and as shown in FIGS. 4C and 4D, the engagement convex portion 121 of the lock member 120 is arranged inside the engagement concave portion 94a ′ and The side guide unit 100R can be fixed at a position corresponding to the B5 size paper by engaging with the triangular protrusion 94b.
And since such an engagement state is based on the combination of a square and a triangle, there is no problem in strength.

The paper feed cassette 18 as described above is a paper feed cassette including a paper position regulating unit 100 that is slidably attached to the bottom surface 94 of the paper feed cassette and can be locked at a position corresponding to the paper size. ,
The paper position regulating unit 100R is
A slider 110 slidably attached to the bottom surface 94 of the paper feed cassette 18;
A locking member 120 provided to be slidable in the vertical direction with respect to the slider 110 and provided with an engaging convex portion 121 that engages and disengages with an engaging concave portion 94a on the bottom surface of the paper feed cassette;
Since both the engaging convex portion 121 and the engaging concave portion 94a are formed in a quadrangular shape when viewed from the direction perpendicular to the sliding direction of the slider 110, the sheet feeding cassette 18 has the following operation. An effect is obtained.
That is, the sheet position regulation is performed by engaging the engagement convex portion 121 provided at the lower portion of the lock member 120 slidable in the vertical direction with respect to the slider 110 with the engagement concave portion 94 a of the bottom surface 94 of the paper feed cassette. The unit 100R can be fixed at a position corresponding to the paper size.
Since the engaging convex portion 121 and the engaging concave portion are both formed in a quadrangular shape when viewed from the direction orthogonal to the sliding direction of the slider 110, the engaging convex portion 121 and the engaging concave portion 94a are formed. It becomes hard to break.
Further, when the lock member 120 slides up and down, the engagement convex portion 121 and the engagement concave portion 94a on the bottom surface of the sheet feeding cassette are engaged and disengaged. Therefore, the lock member side engagement convex portion 121 and the cassette bottom side engagement It is not necessary to provide a gap for enabling the lock member 121 to rotate between the recess 94a.
Accordingly, it is possible to eliminate rattling between the paper feed cassette bottom portion 94 and the paper position regulating unit 100 as much as it is not necessary to provide the gap, so that the slidable paper position regulating unit 100 is brought to a desired position. It can be fixed with high accuracy.
As described above, according to the paper feed cassette 18, the engaging convex portion 121 and the engaging concave portion 94a are not easily damaged, and the slidable paper position regulating unit 100 can be accurately fixed at a desired position. .

  The bottom surface of the engagement protrusion 121 in the lock member 121 is provided with a triangular recess 121a when viewed from the direction orthogonal to the sliding direction of the slider 110, and the engagement recess provided on the cassette bottom corresponding to the paper size. Of the engagement recesses 94a, the interval L1 between the adjacent engagement recesses is shorter than the length L2 of the engagement recess in the sliding direction of the slider 110. Since the triangular protrusion 94b that engages with and disengages from the triangular concave portion 121a is provided, the paper position regulating unit 100 is fixed to a position corresponding to the paper size even for a slightly different size paper. Will be able to.

Since the side guide unit 100 can be accurately fixed at a desired position, the positional accuracy of the paper guided by the side guide unit 100 with respect to the separation claw 93 is improved, and the paper separation failure (results in the weight of the paper being increased). Sending) 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.

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.
For example, in FIG. 2A, reference numeral 140 denotes a trailing edge pressing unit that presses the trailing edge of the sheet, and the configuration of the present invention can be applied to this trailing edge pressing unit.

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. 1B is a cross-sectional view taken along line bb in FIG. The elements on larger scale of FIG.2 (b). (A) is a lock state explanatory view, (b) is a partially enlarged view of FIG. (A), (c) is a lock state explanatory view, and (d) is a partially enlarged view of FIG. (C).

Explanation of symbols

  18: paper feeding cassette, F: paper feeding direction, 93: separation claw, 94: bottom surface, 94a: engaging recess, 94b: triangular projection, 100: side guide unit (paper position regulating unit), 110: slider , 120: a locking member, 121: an engaging convex portion, 121a: a triangular concave portion.

Claims (2)

A paper feed cassette having a paper position regulating unit that is slidably attached to the bottom surface of the paper feed cassette and can be locked at a position corresponding to the paper size,
The paper position regulating unit is
A slider slidably attached to the bottom of the paper cassette;
A locking member provided to be slidable in the vertical direction with respect to the slider, and provided with an engaging convex part that engages and disengages with an engaging concave part on the bottom surface of the paper feed cassette at the lower part;
Both of the engaging convex portion and the engaging concave portion are formed in a square shape when viewed from a direction orthogonal to the sliding direction of the slider. The bottom surface of the engaging convex portion in the lock member is provided with a triangular concave portion when viewed from a direction orthogonal to the sliding direction of the slider,
Of the engagement recesses provided on the cassette bottom surface corresponding to the paper size, the engagement recesses in which the spacing between adjacent engagement recesses is shorter than the length of the engagement recess in the sliding direction of the slider. 2. A paper feed cassette according to claim 1, wherein a triangular projection engaging with and disengaging from the triangular recess is provided on a bottom surface of the engagement recess.

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