JP3864919B2 - Paper feeder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper feeding device used in an image forming apparatus such as a copying machine, a facsimile machine, and a printer.
[0002]
[Prior art]
2. Description of the Related Art Generally, a sheet feeding apparatus that stacks sheet-like sheets on a cassette, mounts the sheet-like sheets on an image forming apparatus main body, and feeds paper is widely used. In such a type of paper feeding device, a mechanism is used in which a coil spring is opened so as to press the paper against the feeding roller in the middle of mounting the cassette. Thus, when setting a paper using a coil spring, it is easy to become trouble when mounting a cassette. That is, it is necessary to depress the coil spring in advance so that the feeding roller and the paper do not collide and the paper is torn or wrinkled, and the coil spring needs to be released so as to press the paper against the feeding roller after the cassette is mounted.
[0003]
In order to cope with such a problem, in Patent Document 1, the dowel provided on the separation claw member of the copy paper is pushed down by the cam plate provided on the cassette receiver of the apparatus main body, and the copy paper contacts the feed roller. The point of wearing so as not to be described. Further, in Patent Document 2, the base plate is pushed down by a groove cam provided on the apparatus main body side and held by a lock claw as the cassette is taken out, so that an operator can replenish paper in the cassette. However, there is no need to push down the base plate.
[0004]
[Patent Document 1]
JP-A-49-18336 [Patent Document 2]
JP-A-6-9077 [0005]
[Problems to be solved by the invention]
However, in the prior art as described above, the biasing member such as a coil spring is constantly biased so as to push up the stacking plate on which the paper is stacked. Therefore, it is necessary to depress the coil spring once and release it. If the coil spring springs up, the leading edge of the paper may turn up or become wrinkled, causing jamming. Although it is conceivable to avoid such a phenomenon by weakening the elastic force of the coil spring, when the elastic force of the coil spring becomes weak, the paper is not sufficiently pressed by the feed roller, and troubles occur in the feeding operation.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a paper feeding apparatus that can prevent troubles caused by springing of a coil spring as described above and can easily perform a paper supply operation.
[0007]
A sheet feeding device according to the present invention is detachably provided in a main body of the apparatus, and stores a cassette body. The cassette body is pivotally supported by the cassette body so as to be movable up and down. A sheet feeding device for feeding sheets one by one from the top into the apparatus main body , wherein the cassette body is mounted in a direction substantially perpendicular to the feeding direction of the feeding means. A shaft member that is disposed between the bottom surface of the cassette body and the stacking plate and that is rotatably supported on the side surface of the cassette body along the mounting direction thereof, and is fixed to the shaft member and rotated by the shaft member. a leaf spring for vertically moving the stacking plate by the dynamic operation, a rotating member coupled to the shaft member while being protruded rotatably outwardly from the mounting direction of the front side of the cassette body, the times When provided on the moving member And a contacting protrusion on the guide surface formed on the engagement portion of the apparatus main body in the mounting state of the cassette body of the apparatus main body, wherein the convex portion is moved downwardly while contacting with the guide surface by rotating member is rotated, the shaft member, characterized in that the leaf spring is held by being rotated so as to push up the said product placing plate.
[0008]
With the above configuration, the leaf spring pushes up the loading plate by the pivoting operation of the shaft member, so that the loading plate is biased after the cassette body is mounted, and the shaft Due to the rotating operation of the members, it is possible to set the paper at a predetermined position without jumping up the stacking plate. Further, by rotating the rotating member connected to the shaft member on the side surface of the cassette body so as to be rotatable, the rotating member is rotated to the engaging portion of the apparatus body in conjunction with the mounting operation of the cassette body. If they are engaged, they can be set without damaging the paper only by the loading operation. Further, the engaging operation of the rotating member and the engaging portion of the apparatus main body is released by the take-out operation of the cassette body, and the stacking plate can be rotated to a position lowered by its own weight so that paper can be easily supplied. .
[0009]
Further, by providing a convex portion on the rotating member and forming the guide surface on the engaging portion of the apparatus main body, the rotating member can be smoothly rotated in conjunction with the mounting operation of the cassette body. It is possible to perform the push-up operation of the stacking plate without giving an impact to the paper. Further, by projecting the rotating member on the front side surface in the mounting direction of the cassette body, the rotating member can be reliably engaged with the engaging portion of the apparatus main body by the force applied at the time of mounting.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments according to the present invention will be described in detail. FIG. 1 is an external perspective view of an image forming apparatus including an embodiment according to the present invention, and FIG. 2 is a partial schematic cross-sectional view showing an internal structure thereof.
[0011]
As shown in FIG. 1, the paper feeding device 1 is arranged at the lower part of the image forming apparatus, and is configured such that the paper feeding cassette 12 is pulled out from the front surface and paper is set and inserted. It goes straight to the (operation panel side) and can be attached and detached. The paper feeding direction of the paper loaded on the paper feeding cassette 12 is set within a plane including an arrow, and the paper feeding cassette 12 can be attached and detached in a direction orthogonal to the paper feeding direction.
[0012]
As shown in FIG. 2, a sheet feeding device 1 is disposed at the bottom of the image forming apparatus, and a sheet conveying unit 2 and a recording unit 3 are disposed on the top thereof. Although not shown in the drawing, a document reading unit, a document transport device, and the like are arranged on the upper portion of the recording unit 3.
[0013]
In the paper feeding device 1, a metal frame 11 that supports a paper feeding cassette 12 is disposed in a resin frame 10. The paper feed cassette 12 is detachable by sliding in a direction perpendicular to the paper surface in FIG. In the paper feed cassette 12, the paper 14 is stacked on a flapper 15 that is a stacking plate, and the rear end thereof is in contact with the end guide 13. The flapper 15 is pivotally supported by the paper feed cassette by pins 16 so as to be movable up and down. A plate spring, which will be described later, is provided on the lower surface, and the flapper 15 is pushed upward. The leading edge of the paper 14 pushed up by the leaf spring is pressed against the paper feeding roller 17.
[0014]
The sheet feeding roller 17 is provided in the sheet feeding cassette 12, and a pad 18 and a pad support member 19 that supports the pad 18 are also disposed in the sheet feeding cassette 12. The pad 18 is pressed by a spring 20 at a position close to the front end of the paper 14 of the paper feeding roller 17. By rotating the paper supply roller 17, the leading end of the paper 14 is pulled in and is sandwiched between the pad 18 and fed one by one along the paper guide 21 to the upper paper transport unit 2.
[0015]
In the paper transport unit 2, the fed paper is transported to the recording unit 3 by feed rollers 22 and 23. The recording unit 3 includes a developing device 24, a charging brush 27, a photosensitive drum 28, a transfer roller 29, an exposure head 30, and a fixing roller 31 for recording on the paper conveyed by the paper conveyance unit 2. First, the surface of the photosensitive drum 28 is uniformly charged by the charging brush 27, and the charged photosensitive drum 28 is exposed by the exposure head 30 in accordance with an image recording signal, thereby forming an electrostatic latent image. Next, the toner in the developing device 24 is transferred from the supply roller 25 to the electrostatic latent image formed on the photosensitive drum 28 via the developing roller 26 to be visualized, and the surface of the photosensitive drum 28 is transferred by the transfer roller 29. The toner image formed on the sheet is transferred to a sheet. The transferred toner image is sandwiched between the fixing roller 31 and the press roller 32 and heated and pressed to be fixed on the paper. The fixed sheet is carried out to the discharge tray 34 by the discharge roller 33.
[0016]
FIG. 3 is a perspective view of the paper feed cassette 12 removed from the apparatus main body. A space for stacking sheets is formed in the sheet feeding cassette 12, and a plate-like flapper 15 is disposed on the bottom surface. In the flapper 15, the end of the main body 40 on the side of the paper feeding roller 17 is bent at a predetermined angle to form a contact portion 41, and the end guide 13 moves to the end opposite to the contact portion 41. Notches are formed so that they can be formed, and attachment portions 42 are erected along the inner side surface of the sheet feeding cassette 12 at both end portions thereof. The flapper 15 is pivotally attached to each attachment portion 42 with the pin 16 as a fulcrum, and is movable up and down. Further, a non-slip pad 43 is attached to the contact portion 41 at a portion that contacts the paper feed roller 17.
[0017]
The rotation shaft 44 of the sheet feeding roller 17 is supported by bearings 45 and 46 erected on the upper surface of the sheet feeding cassette 12, and a gear 47 connected to the apparatus main body at the time of mounting is fixed to one end thereof. Has been. Therefore, the pad of the pad support member 19 is always in pressure contact with the paper feed roller 17.
[0018]
When the paper is placed in the paper feed cassette 12, the end guide 13 is moved away from the flapper 15 to place the paper on the upper surface of the flap 15, and the front guide 48 to which the paper feed roller 17 is attached. One side of the paper is put into contact with the paper, the side edges of the paper are aligned with the side guides 49, and the end guide 13 is put on the paper to set the paper.
[0019]
When the paper feed cassette 12 is attached to the apparatus main body, it is moved in the direction of the arrow and attached. Therefore, the sheet feeding roller 17 is mounted in a direction substantially orthogonal to the feeding direction.
[0020]
FIG. 4 shows a state in which the end guide 13, the flapper 15, the paper feed roller 17, and the side guide 49 are removed from FIG. 3. A shaft member 50 is disposed along the mounting direction on the bottom surface inside the paper feed cassette 12, and both ends thereof are pivotally supported on the inner side surface of the paper feed cassette 12. A shaft support member 51 is fixed to one end, and is fitted into a hole formed in the inner surface of the paper feed cassette 12. The other end is inserted into a hole that penetrates the side of the paper cassette 12 and is connected so that the rotating member 52 protrudes from the outer surface on the front end side in the insertion direction of the paper cassette 12. Yes. Two leaf springs 53 are fixed to the central portion of the shaft member 50.
[0021]
In FIG. 5, the perspective view regarding the shaft member 50 is shown. The shaft member 50 is made of a hollow tubular body made of metal and having a rectangular cross section, and the shaft support member 51 is made of synthetic resin and is fixed by inserting one end of the shaft member 50 into a central hole. ing. The shaft support member 51 is formed with a flange portion 54 that contacts the inner surface of the paper feed cassette 12 and a support portion 58 that fits into the hole of the paper feed cassette 12. The rotating member 52 has a plate-like base portion 54 and a rod-like convex portion 55 protruding outward. The other end of the shaft member 50 is inserted into a hole formed in the base portion 54, and the inserted end is bent to form a fixing portion 57. When the fixing portion 57 is inserted into the mounting groove 56 of the base portion 54 and the rotating member 52 is connected to the shaft member 50, when the rotating member 52 rotates, the shaft member 50 also rotates. The two leaf springs 53 are formed in a rectangular shape, and one end thereof is fixed to one of the four surfaces forming the outer surface of the shaft member 50. Accordingly, the leaf spring 53 is moved up and down by the rotation of the shaft member 50, and the rotation axis direction of the movement of the leaf spring 53 and the mounting direction of the sheet feeding cassette 20 are matched.
[0022]
When the paper feed cassette 12 is removed from the apparatus main body, the plate spring 53 is in contact with the bottom surface of the paper feed cassette 12 by its own weight as shown in FIG. The base part 54 of 52 inclines so that the convex part 55 may be located upwards.
[0023]
FIG. 6 is a perspective view of a state in which the paper feed cassette 12 is mounted in the apparatus main body. FIG. 7 shows a state in which the end guide 13, the flapper 15, the paper feed roller 17, and the side guide 49 are removed from FIG. 6. When the paper feed cassette 12 is mounted, the convex portion 55 of the rotating member 52 projecting from the front side surface in the mounting direction engages with the engaging portion of the apparatus main body while rotating, as will be described later. Thus, the convex portion 55 rotates clockwise to substantially the same height as the shaft member 50. Therefore, the shaft member 50 also rotates clockwise by the same angle, and the leaf spring 53 moves upward and acts to push up the lower surface of the main body 40 of the flapper 15. The flapper 15 is rotated upward by the pushing force of the leaf spring 53 so that the stacked sheets are pressed against the sheet feeding roller 17. In FIG. 6, since there is no sheet, the pad 43 of the contact portion 41 of the flapper 15 is pressed.
[0024]
FIG. 8 shows a process in which the rotating member 52 performs a rotating operation when the paper feed cassette 12 is mounted. On the apparatus main body side, a guide surface 60 is formed at a position where the convex portion 55 of the rotating member 52 contacts. The guide surface 60 is formed so as to incline downward along the mounting direction of the paper feed cassette 12, and an engaging surface 61 formed of a flat surface along the mounting direction is formed at the tip of the guide surface 60. As shown in FIG. 8A, when the paper feed cassette 12 is inserted into the apparatus main body in the direction of the arrow, the convex portion 55 comes into contact with the guide surface 60. Further, when the paper feed cassette 12 is inserted, the convex portion 55 moves downward along the inclination while being in contact with the guide surface 60, and the rotating member 52 is rotated. And as shown in FIG.8 (b), if the convex part 55 is inserted to the engaging surface 61 (paper feeding position), the rotation member 52 will be hold | maintained in that position.
[0025]
When the paper feeding cassette 12 is taken out, the convex portion 55 is released while the convex portion 55 is separated from the engaging surface 61 and abuts against the guide surface 60. Accordingly, since the rotating member 52 is gradually rotated along the guide surface 60, the leaf spring 53 also gradually pushes up the flapper 15 in the same manner, and the stacked sheets are not subjected to an impact.
[0026]
In the above example, the two rectangular leaf springs are fixed to the shaft member, but the number is not limited, and one leaf spring may be cut out and used. Furthermore, it can also be adjusted so that the force of pushing up the leaf springs at both ends and the center is different. With respect to the fixing direction to the shaft member, it is possible to attach not only to the feeding roller direction but also to the opposite direction.
[0027]
In recent years, in color printers, color copiers, and the like, products that can handle thin paper such as recycled paper and glossy paper for photography to thick paper have been desired. However, as in the above-described embodiment, the leaf spring is rotated a predetermined angle. If the sheet is moved and pressed against the feeding roller, the sheet is always pressed against the feeding roller with a constant pressure regardless of the sheet thickness.
[0028]
Further, as long as the rotating member 52 can be rotated, a structure other than the above-described convex portion may be adopted.
[0029]
Further, as shown in FIG. 9, the present invention can be applied even when a paper feed roller is not attached to the paper feed cassette 12. That is, since the leaf spring is in contact with the bottom surface of the paper feed cassette 12 before mounting, the paper feed cassette 12 is mounted in the apparatus main body in that state, and the flapper 15 is pushed up by the leaf spring. Thus, it is possible to load the paper without contacting the paper feed roller in the apparatus main body and set the paper. In the paper feed cassette 12 shown in FIG. 9, two abutting protrusions 70 are formed on the front guide 48. The contact protrusion 70 has a flat portion in the vertical direction, and the front end of the stacked paper is easily aligned by the front end of the paper contacting the flat portion. That is, if the contact protrusion 70 is not formed, the entire leading edge of the sheet contacts the front guide 70 and a load is applied to the sheet, but the load applied to the sheet by the contact protrusion can be reduced. The tips are easier to align.
[0030]
Further, a guide portion 71 is provided so as to extend from the abutting projection portion 70 on the upper surface of the sheet feeding cassette 12 and is continuous with the guide portion 72 formed in a convex shape on the guide member 72 on the apparatus main body side. A guide surface is formed. Protruding the guide portion in this way can prevent the leading end of the sheet from being caught by the guide member 72 on the apparatus main body side when the sheet is fed.
[0031]
【The invention's effect】
As described above, in the present invention, since the biasing member pushes up the stacking plate by the pivoting operation of the shaft member, the stacking plate is biased after the cassette body is mounted, Because of the pivoting movement of the shaft member, the paper can be set at a predetermined position without jumping up the stacking plate. Further, by rotating the rotating member connected to the shaft member on the side surface of the cassette body so as to be rotatable, the rotating member is rotated to the engaging portion of the apparatus body in conjunction with the mounting operation of the cassette body. If they are engaged, they can be set without damaging the paper only by the loading operation. Further, the engaging operation of the rotating member and the engaging portion of the apparatus main body is released by the take-out operation of the cassette body, and the stacking plate can be rotated to a position lowered by its own weight so that paper can be easily supplied. .
[0032]
Further, by providing a convex portion on the rotating member and forming the guide surface on the engaging portion of the apparatus main body, the rotating member can be smoothly rotated in conjunction with the mounting operation of the cassette body. It is possible to perform the push-up operation of the stacking plate without giving an impact to the paper. Further, by projecting the rotating member on the front side surface in the mounting direction of the cassette body, the rotating member can be reliably engaged with the engaging portion of the apparatus main body by the force applied at the time of mounting.
[Brief description of the drawings]
FIG. 1 is an external perspective view of an image forming apparatus including an embodiment according to the invention.
FIG. 2 is a partial schematic cross-sectional view showing an internal structure of the image forming apparatus of FIG.
FIG. 3 is a perspective view of a paper feed cassette according to an embodiment of the present invention.
4 is a perspective view showing a state in which some components of the paper feed cassette of FIG. 3 are removed. FIG.
5 is a perspective view of a shaft member used in the paper feed cassette of FIG.
FIG. 6 is a perspective view relating to a mounted state of the paper feed cassette according to the embodiment of the present invention.
7 is a perspective view showing a state in which some parts of the paper feed cassette of FIG. 6 are removed. FIG.
FIG. 8 is a diagram for explaining a rotating operation of a rotating member.
FIG. 9 is a perspective view of another example relating to a paper feed cassette.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Paper feeder 2 Paper conveyance part 3 Recording part
10 Resin frame
11 Metal frame
12 Paper cassette
13 End guide
14 paper
15 Flapper
16 pin
17 Feed roller
18 pads
19 Pad support member
20 Biasing member
21 Paper guide
50 shaft member
51 Shaft support member
52 Rotating member
53 Leaf spring
54 Base part
55 Convex

Claims (1)

A cassette body that is detachably provided in the apparatus main body and that stores paper, a loading plate that is pivotally supported by the cassette body so as to be movable up and down, and stacks the paper, and the stacked body one by one from the top A sheet feeding device , wherein the cassette body is mounted in a direction substantially orthogonal to the feeding direction of the feeding means, and between the bottom surface of the cassette body and the stacking plate. And a shaft member that is rotatably supported on the side surface of the cassette body along the mounting direction thereof, and is fixed to the shaft member, and the stacking plate is moved up and down by the rotation of the shaft member. A leaf spring to be moved, a pivot member protruding outwardly from a front side surface in the mounting direction of the cassette body and connected to the shaft member, and provided on the pivot member and the cassette body Equipment And a contacting protrusion in the guide surface formed on the engagement portion of the apparatus main body in the attached state to the body, the pivot member and the convex portion is moved downwardly while contacting with the guide surface rotates by, the shaft member includes a sheet feeding apparatus, characterized in that the leaf spring is held by being rotated so as to push up the said product placing plate.

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