JP2008030864A - Paper feed cassette - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feed cassette in which the pressure of a delivery roller is uniformly applied to right and left surfaces of a printing medium even when the thickness of right and left side parts of the printing medium set on a cassette body of an image forming device is different from each other. <P>SOLUTION: A bottom plate 5 of a cassette body of an image forming device is divided into a rear plate 7 and a front plate 6. A supporting shaft 17 for supporting the front plate 6 is provided on the rear plate 7 toward the delivery direction of a printing medium, and the front plate 6 is capable of vertically rocking right and left ends of the front plate 6 orthogonal to the delivery direction of the printing medium with the supporting shaft as an axis. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a paper feed cassette that is provided in an image forming apparatus such as a printing machine or a copying machine and that can handle print media having different thicknesses such as an envelope.

FIG. 7 is a sectional view of a general paper feed cassette used in a conventional image forming apparatus such as a printing machine, a copying machine, and a facsimile machine.
The sheet feeding cassette supports the rear end portion of the bottom plate 5 on the bottom wall 4a of the rectangular box-shaped cassette body 4 with a rotating shaft 9, and the bottom plate 5 supports the rotating shaft 9 on the bottom wall 4a. The front end portion can be turned up and down around the center. A spring (not shown) is provided between the bottom plate 5 and the bottom wall 4a of the cassette body 4 to push the bottom plate 5 upward, and the front end of the paper P placed on the bottom plate 5 is the bottom plate. The structure is pushed up by 5.

The wall 4a on the front end side of the paper feed cassette 1 is provided with one paper feed roller 10b of the pair of paper feed rollers, and the other paper feed roller 10a is attached to the main body side of the image forming apparatus. ing. When the paper feed cassette 1 is mounted on the paper feed unit of the image forming apparatus and the paper P is set on the bottom plate 5, the feed roller 8 comes into pressure contact with the uppermost paper in the paper feed cassette 1, and the feed roller The paper is preferably fed to the printing unit side of the image forming apparatus by a pressure contact force of 8.
The remaining uppermost sheet P is pushed up by the bottom plate 5 and is always maintained in a state in which the uppermost sheet is pressed against the delivery roller 8. The paper fed out by the feed roller 8 is sent to a printing unit in which a photosensitive drum or the like is disposed (see Patent Document 1).
JP 2004-196436 A JP-A-5-004731

Usually, the bottom plate is made of an integral plate and is made of a rigid material that does not deform. There is no problem with ordinary sheets having the same overall thickness, but as shown in FIG. 8, printing media having different left and right thicknesses such as an envelope 11 may be printed. The envelope 11 has a flap 11a on one side, the thickness of the envelope 11 is different between the right side 11b with the flap 11a and the left side 11c without the flap 11a, and many bundles of envelopes 11 are loaded on the cassette. , Left and right thickness will be greatly different.
Then, although the bottom plate 5 and the delivery roller 8 are disposed in parallel, the uppermost envelope 11 is disposed at an inclination angle θ from the horizontal line (the delivery roller shaft) L. The right side portion 11b on the 11a side touches one of the delivery rollers 8a, but a gap is formed between the left side portion 11c of the envelope 11 and the other delivery roller 8b, or a pressure contact force is not applied to the envelope 11. There is.

Thus, when the envelope 11 is inclined, due to the difference in thickness between the left and right end portions of the envelope 11, the pressure contact force of the other delivery roller 8b does not act on the envelope 11, and skew is likely to occur. In addition, in order to stabilize the paper feeding performance, there is a problem that a large number of envelopes cannot be set at one time.
The present invention has been made in view of such circumstances, and even if the thickness of the left and right sides of the print medium set in the cassette body is different, the pressure contact force of the delivery roller is applied to the left and right surfaces of the print medium. It is an object of the present invention to provide a paper feed cassette that applies evenly.
In addition, there exists a technique of the above-mentioned patent document 2 which corrects that the right and left both ends of an envelope are raised rather than a center part and become thick with printing media, such as an envelope.

In order to achieve the above object, the paper feed cassette of the present invention is provided with a bottom plate for placing a print medium on the cassette body of the image forming apparatus, and the print medium is moved upward on the bottom plate. A feed roller that extends in the horizontal direction and has a rotation shaft on the rear end side of the bottom plate in the print medium feed direction, and the bottom plate is directed upward on the front end side of the bottom plate. In a paper feed cassette provided with an elastic member so that the bottom plate can be rotated up and down about the rotation axis as a center, in a direction perpendicular to the print medium feeding direction. The left and right end portions of a certain bottom plate are configured to be swingable up and down.
In order to achieve the above object, the paper feed cassette of the present invention is provided with a bottom plate for placing the print medium on the cassette body of the image forming apparatus, and above the print medium above the bottom plate. A feed roller extending in the horizontal direction is provided, a rotation shaft is provided on the rear end side of the bottom plate in the print medium feed direction, and the bottom plate is placed on the front end side of the bottom plate. In the sheet feeding cassette provided with an elastic member so that the bottom plate can be rotated up and down around the rotation axis as the axis, the bottom plate is disposed on the rear plate and the front plate. The rear plate and the front plate are provided with support shafts that extend in the print medium feeding direction and support the rear plate and the upper front plate. The left and right ends of the front plate, which is the direction perpendicular to the print medium feeding direction, with the support plate as the center axis, swing up and down according to the left and right thickness of the print medium. It became possible to move.
The sheet feeding cassette may be provided with elastic members that urge the bottom plate toward the upper side of the bottom plate at both left and right ends of the front plate, which are orthogonal to the print medium feeding direction.
Further, the sheet feeding cassette may be provided with a fixing means for preventing the front plate from swinging and making the surface of the front plate flush with the surface of the rear plate.

The paper feed cassette according to the present invention is provided with a bottom plate for placing the print medium on the cassette body of the image forming apparatus, and the upper portion of the bottom plate regulates the upward movement of the print medium and has a horizontal axis. A feed roller extending from the bottom plate, a rotation shaft provided on the rear end side of the bottom plate in the print medium feeding direction, and urging the bottom plate upward on the front end side of the bottom plate, In the paper feed cassette provided with an elastic member so as to be pivotable up and down with the pivot shaft as a center, both left and right end portions of the bottom plate that are perpendicular to the print medium feeding direction However, since it is configured to be able to swing up and down, skew of the print medium can be prevented even if the thickness of the print medium differs between the left and right ends of the print medium.
The paper feed cassette of the present invention is provided with a bottom plate for placing the print medium on the cassette body of the image forming apparatus, and the upper part of the bottom plate regulates the upward movement of the print medium in the horizontal direction. A feed roller extending in the axis, a rotation shaft provided on the rear end side of the bottom plate in the print medium feed direction, and urging the bottom plate upward on the front end side of the bottom plate; In the paper feed cassette provided with an elastic member so that the bottom plate can be rotated up and down around the rotation axis, the bottom plate is divided into a rear plate and a front plate, and the rear plate The front plate is provided with a support shaft that extends in the print medium feeding direction and supports the rear plate and the upper front plate, and the front plate supports the support plate. The left and right ends of the front plate, which is a direction orthogonal to the print medium feeding direction, can be swung up and down according to the thickness of the left and right of the print medium. Therefore, even if the thickness of the print medium differs between the left and right ends of the print medium, the skew of the print medium can be prevented.
In the paper feed cassette, elastic members for urging the bottom plate toward the upper side of the bottom plate are disposed at both left and right ends of the front plate perpendicular to the feeding direction of the print medium. A stable pressure contact force can be applied to the feed roller 8 from both sides, and a stable pressure contact force can be applied to the feed roller from both sides of the bottom plate.
The paper feed cassette is provided with fixing means for preventing the front plate from swinging so that the front plate surface is flush with the rear plate surface. Printing is possible with the front plate being stable.

Hereinafter, a paper feed cassette according to an embodiment of the present invention will be described with reference to the drawings. In addition, the substantially same part as FIG.7 and FIG.8 is shown with the same code | symbol. In addition, the direction indicated by the arrow Y in the figure is the front side of the paper feed cassette, and the left and right directions will be described with reference to the state when the paper feed cassette is viewed from the front.
FIG. 1 is a perspective view of a sheet feeding cassette according to the present invention as viewed obliquely from above, and FIG. 2 is a simplified cross-sectional view of the sheet feeding cassette as viewed from the side. The paper feed cassette 1 is provided with a substantially rectangular dish container-shaped cassette body 4 that opens upward. A bottom plate 5 on which a print medium is placed is provided on the bottom wall 4 a of the cassette body 4. The bottom plate 5 is divided into two in the front-rear direction on the print medium delivery direction Y side, a front plate 6 is disposed on the front side, and a rear plate 7 is disposed on the rear side. The material and thickness of the front plate 6 and the rear plate 7 can be those of a normal bottom plate.

  Referring to FIGS. 2 and 3, the rear plate 7 is provided with a mounting flange 7a projecting so as to be bent downward from the plate surface at the rear end side portion, and the mounting flange 7a is provided with a support hole 7b. In the left and right side walls 4c and 4d of the cassette body 4 shown in FIG. 1, the support shaft 13 supports the rotation shaft 9 (only the reference numeral) supported by the support hole 7b. In this way, the paper feed cassette 1 has the rotation shaft 9 pivotally supported in the support hole 7b, and the front end side of the bottom plate 5 in the direction indicated by the arrow a in FIG. It is configured to be rotatable in the vertical direction.

  As shown in FIG. 3, a tongue-shaped front bearing fitting 15 a that protrudes downward from the lower surface is fixed to the rear side of the front plate 6. On the other hand, a tongue-shaped front bearing fitting 15b that protrudes downward from the lower surface is fixed to the front side of the rear plate 7, and similarly, a rear bearing that protrudes downward from the lower surface to the rear side of the rear plate 7. The metal fitting 15c is fixed. Each of these bearing fittings 15 a to 15 c is arranged in a straight line at the center in the left-right direction of the front plate 6 and the rear plate 7. Bearing holes 16a to 16c are formed inside each of the bearing fittings 15a to 15c, and a support shaft 17 is pivotally supported inside each of the bearing holes 16a to 16c.

3 and 4, a coil spring 19 having a lower end fixed to the bottom wall 4 a of the cassette body 4 is provided at the front portion of the front plate 6, and a bearing joint 20 is attached to the upper end portion of the coil spring 19. ing. As shown in FIG. 4, the bearing joint 20 forms a pair of inverted U-shaped receiving portions 20c disposed on the pedestal 20a with a space therebetween. The upper end of the coil spring 19 is attached to the bottom of the bearing joint 20.
On the other hand, a tongue piece 6a projecting downward is formed at the front end portion of the front plate 6, and the tongue piece 6a is inserted between a pair of receiving portions 20c. The tongue piece 6a and the receiving portion 20c support shafts. 17 is rotatably supported. As described above, the front plate 6 has the support shaft 17 as an axis with respect to the rear plate 7 and the bearing joint 20, and the left and right ends of the front plate 6 are vertically moved in the direction indicated by the arrow b in FIG. 3. What is necessary is just to be comprised so that rocking | fluctuation is possible. Since the mounting flange 7a cannot move in the vertical direction, the left and right ends of the rear plate 7 cannot swing in the vertical direction.

The front plate 6 and the rear plate 7 are integrally connected via a support shaft 17, and the front plate 6 and the rear plate 7 are integrated with each other about the rotation shaft 9. It is comprised so that the front-end part of can be moved up and down.
The coil spring 19 is attached so that the front end side of the front plate 6 of the bottom plate 5 can be turned up and down and the bottom plate 5 is elastically biased upward. As shown in FIG. 2, the feed roller 8 is pivotally supported on the support shaft 23 above the front end side of the bottom plate 5. The support shaft 23 is oriented in the horizontal direction to the main body of the image forming apparatus, and is provided with two delivery rollers 8 having the same shape on the left and right. The support shaft 23 is supported on the image forming apparatus main body side so as to be rotatable by a driving unit (not shown). The feed roller 8 abuts on the top surface of the uppermost end of the print medium stacked on the bottom plate 5 and biased upward, and rotates to sequentially feed the print media.
As shown in FIG. 2, a lower paper feed roller 10 b is disposed on the front wall 4 b of the cassette body 4, and the upper paper feed roller 10 b is disposed on the image forming apparatus main body side. A roller 10a is attached.

The sheet feeding cassette 1 is provided with a regulating member 12 on the rear end side of the cassette body 4. The L-shaped regulating member 12 includes a base portion 12a and a standing portion 12b, and is configured to be slidable in the front-rear direction of the cassette body 4. And it contacts the rear end of the printing medium placed on the bottom plate 5 and plays a role of preventing the printing medium from shifting backward (the regulating member 12 is omitted in other figures).
The cassette body 4, the bottom plate 5, the feed roller 8, the paper feed rollers 10a and 10b and the like have other attached components, a drive system, etc., but do not constitute a novel feature of the present invention. Details of these configurations will not be described.

Next, the operation of the paper feed cassette of the present invention will be described.
A paper feed cassette 1 is disposed in an image forming apparatus (not shown) so as to be able to be pulled out in the forward direction of the cassette. When the envelope 11 is set as a printing medium in the paper feed cassette 1, the bundle of envelopes 11 is placed on the bottom plate 5 of the cassette body 4 with the paper feed cassette 1 being pulled out. As an example, as shown in FIG. 5, when the flap 11 a of the envelope 11 is positioned on the right side wall 4 d of the cassette body 4, the right side of the bundle of envelopes 11 becomes thick.

  In a state where the bundle of envelopes 11 is set in the paper feed cassette 1, the front plate 6 is pressed upward by the urging force of the coil spring 19, and the envelope 11 is sandwiched between the feed roller 8 and the front plate 6. In this state, the upward movement of the envelope 11 is restricted by the delivery roller 8. In a portion where the flap 11a on the right side of the envelope is present, an elastic force is generated by the swelling of the flap 11a. In this state, since the pair of delivery rollers 8 are regulated in a horizontal state, the elastic force of the envelope 11 acts downward to the right of the front plate 6, and the right end of the front plate 6 uses the support shaft 17 as a rotation shaft. Inclined downward, the rotation of the left end side of the front plate 6 is restricted by the envelope 11 and the delivery roller 8 and is inclined with respect to the horizontal direction (send roller axis) L by an angle θ. Since the rear plate 7 is not inclined with respect to the axial direction of the delivery roller 8, the stacked state of the envelope 11 can be stabilized.

Since the uppermost envelope 11 is parallel to the axial direction of the delivery roller 8 and is in contact with any of the pair of delivery rollers 8, the delivery roller 8 is moved to the envelope when a print command is issued. 11 can be sent to the paper feed rollers 10a and 10b.
The envelope 11 delivered by the delivery roller 8 passes between a pair of upper and lower paper feed rollers 10a and 10b. For example, in a copying machine using an electrostatic latent image, a pair of registration rollers (not shown) for registering sheets. Is sent to a photosensitive drum (not shown).

  When the envelopes 11 are sequentially printed and the number of envelopes decreases, the value of the angle θ decreases, the front plate 6 approaches the horizontal direction, and even if the number of envelopes 11 becomes several, the coil spring 19 Since the front plate 6 is arranged at the center of the left and right, an equal pressure contact force is applied to the left and right delivery rollers 8 so that the envelope 11 can be stably fed to the feed rollers 10a and 10b, and the envelope 11 is skewed. Can be prevented. When printing the back surface of the envelope 11, the flap 11a is positioned on the left side of the bundle of envelopes 11, but the left side of the front plate 6 is inclined downward, and printing is possible in the same manner as the front side.

  When a normal sheet having the same overall thickness is set in the paper feed cassette 1 instead of the envelope 11, the front plate 6 is not inclined and is parallel to the feed roller 8, so that the print medium is used as usual. It is possible to print a sheet of paper. In this case, although the surface of the front plate 6 and the surface of the rear plate 7 are flush with each other, a fixing member for fixing the front plate 6 to the rear plate 7 is provided, or a lock member for preventing the inclination of the front plate 6 is provided. It may be provided to prevent the front plate 6 from swinging left and right.

While the embodiments of the present invention have been described above, the present invention can of course be modified or changed in various ways based on the technical idea of the present invention.
In the above embodiment, the pair of delivery rollers 8 are arranged on the left and right, but one delivery roller 8 may be arranged at the center position on the left and right of the bottom plate 5 as shown in FIG. Since the position of the coil spring 19 is also at the left and right center position of the bottom plate 5, the rotational force of the delivery roller 8 can be stably applied to the center of the envelope 11, and skew can be prevented.

6, two coil springs 22 may be disposed at the left and right end portions of the front plate 6 and the central coil spring 19 may be omitted (even if there is only one feed roller 8). Even in the case of single pieces). A stable pressure contact force can be applied to the delivery roller 8 from both sides of the bottom plate 5.
Furthermore, the front plate 6 and the rear plate 7 may be integrated, and both ends of the integrated bottom plate 5 may be swung up and down. In this case, it is necessary to support the integral bottom plate 5 only by the support shaft 17 and to support the rear end side of the support shaft 17 by a universal joint or the like so as to be rotatable. However, in this case, it is necessary to dispose two coil springs 22 on the front side of the bottom plate 5.

It is the whole perspective view seen from the slanting upper part of the paper feed cassette of an embodiment of the invention. It is sectional drawing which looked at the paper feed cassette of FIG. 1 from the side surface direction. FIG. 2 is a perspective view of a bottom plate and a delivery roller in FIG. 1. It is an expansion perspective view which shows the connection structure of the front-end part of a bottom plate of FIG. 1, and a bearing joint. FIG. 2 is a perspective view of a state in which envelopes are stacked as print media on the bottom plate of the paper feed cassette of FIG. 1. It is a perspective view of the bottom plate and delivery roller by the modification of embodiment of this invention. It is sectional drawing which looked at the conventional paper feed cassette from the side surface direction. It is a perspective view of the state which loaded the envelope as a printing medium on the bottom plate of the conventional paper feed cassette.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feed cassette 4 Cassette main body 5 Bottom plate 6 Front side plate 7 Rear side plate 8 Sending roller 9 Rotating shaft 11 Envelope 11a Flap 15a-15c Bearing metal fittings 16a-16c Bearing hole 17 Support shaft 19 Coil spring 20 Bearing joint

Claims (4)

A bottom plate for placing the print medium is provided on the cassette body of the image forming apparatus, and a feed roller is provided on the top of the bottom plate to regulate the upward movement of the print medium and to have a horizontal axis extending in the horizontal direction.
A rotation shaft is provided on the rear end side of the bottom plate in the print medium feeding direction, the bottom plate is urged upward on the front end side of the bottom plate, and the bottom plate is pivoted on the rotation shaft. In the paper feed cassette provided with an elastic member so that it can be rotated up and down around the center,
A paper feed cassette characterized in that the left and right ends of the bottom plate, which are perpendicular to the print medium feeding direction, are configured to swing up and down. A bottom plate for placing the print medium is provided on the cassette body of the image forming apparatus, and a feed roller is provided on the top of the bottom plate to regulate the upward movement of the print medium and to have a horizontal axis extending in the horizontal direction.
A rotation shaft is provided on the rear end side of the bottom plate in the print medium feeding direction, the bottom plate is urged upward on the front end side of the bottom plate, and the bottom plate is pivoted on the rotation shaft. In the paper feed cassette provided with an elastic member so that it can be rotated up and down around the center,
The bottom plate is divided into a rear plate and a front plate, the rear plate and the front plate are provided with a support shaft that extends in the feeding direction of the print medium and supports the rear plate and the front plate,
The left and right ends of the front plate, which are perpendicular to the feeding direction of the print medium, centered on the support shaft, swing up and down depending on the thickness of the print medium. A paper cassette that can be moved.   The elastic member for urging the bottom plate toward the upper side of the bottom plate is disposed at both left and right ends of the front plate orthogonal to the feeding direction of the print medium. Paper cassette.   4. The fixing device according to claim 1, further comprising a fixing unit that prevents the front plate from swinging so that a surface of the front plate is flush with a surface of the rear plate. 5. Paper cassette.

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