JPH0312757Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a paper feeding device for a copying machine, and more particularly to a paper feeding device that can prevent copy paper from curling when taking out copy paper one by one from a paper feeding cassette. .

As shown in FIG. 1, conventionally, in a copying machine in which an upper document table 1 moves, a light source 2 shines light onto a document 3 to be copied, and the document image irradiated with the light is transferred to a plurality of mirrors 4. an optical device 7 that forms an image on a photoreceptor drum 6 with a lens 5; a toner supply device 8 that supplies the necessary toner to the photoreceptor drum 6; and copy paper stacked and stored in a paper feed cassette 9. a paper feeding device 10 that feeds paper one sheet at a time, and the paper feeding device 1
A transfer device 1 transfers a toner image formed on the surface of a photoreceptor drum onto copy paper fed by a transfer device 1.
0a, and a fixing device 11 for fixing the transferred toner image onto copy paper.

Partial details of the paper feeding device 10 are shown in FIG.
As shown in the figure, the front end of the copy sheets 12 stacked in the paper feed cassette 9 in the take-out direction is pressed against the paper feed roller 13 by a push-up member 22 (shown in the third figure) made of a spring or the like. Both side edges 17 of the front end in the take-out direction
is the separation claw 14 pressed against the upper surface of the front edge 17.
A presser guide 15 is fixed to the front end of the copy paper 12, either in contact with the surface of the copy paper 12 or with a slight gap therebetween.

In this state, when the paper feed roller 13 is rotated in the direction of arrow F, the top layer of copy paper 12 is sent out with its front edge 17 held by the separating claw 14, as shown in FIG. , the front end 12' behind the front edge 17 is bent as shown in the third figure, and the top layer of copy paper 12 is separated from the second and subsequent layers of copy paper in contact with it. The separated uppermost layer of copy paper 1 is then separated by further rotation of the paper feed roller 13.
Only 2 is sent forward.

At this time, the front end 1 of the copy paper being sent out
Since the presser guide 15 provided at the upper part of the paper sheet 2' is pressed against the paper sheet 2', the width of the bent portion in the take-out direction is regulated, and separation of the uppermost layer of copy paper 12 is ensured.

However, if the vertical position of the presser guide 15 fixed by a mounting member (not shown) is too high above the top layer of copy paper 12 and the distance therebetween is too large, the bending radius of the copy paper 12 becomes large. , due to frictional force, electrostatic force, etc.
Copy paper 12 where the copy paper after the first sheet is the top layer
The copy paper adheres to the copy paper and bends along with it, reducing the separation function.As a result, more than one copy paper is transported from the paper feed cassette 9 at a time.

Furthermore, if the vertical position of the presser guide 15 is too low and too close to the top layer of copy paper 12, the bending radius will become small, making it easy to separate the copy paper 12. etc., the front edge 12' of the copy paper 12 tends to bend and become stiff, which makes it more likely to cause jams, image blurring during transfer, poor fixing, etc.

Therefore, the mounting position of the presser foot guide 15 needs to be determined after sufficient consideration. However, if the presser foot guide 15 is fixed, even if the material or thickness of the copy paper changes, As mentioned above, two-sheet feeding of copy paper, jamming, blurring of images during transfer, and poor fixing occur.

The present invention solves the above-mentioned drawbacks of the conventional methods, does not cause the copy paper to bend even if the material and thickness of the copy paper is changed, and allows copy paper to be reliably taken out one by one from the paper feed cassette and transported to the next process. The purpose of this device is to provide a paper feed device for a copying machine that can press a paper feed roller against the top surface of copy sheets stored in a stack in a paper feed cassette. When the paper feed roller is rotated to feed the top layer of copy paper from the paper feed cassette, the front edge of the copy paper is hooked on the separation claw and fed out, thereby separating the front edge of the copy paper from the paper feed cassette. In a paper feeding device for a copying machine, the top layer of copy paper is separated from the second and lower layers of copy paper and sent out by bending the paper.
A plurality of presser guides provided symmetrically above the bent portion of the copy paper are supported at fixed positions on the copying machine main body in a state where they can be moved up and down by the repulsive force of the bent copy paper. It provides a paper feeding device for a certain copying machine.

Next, embodiments of the present invention will be explained with reference to the attached drawings starting from FIG. 4 to provide an understanding of the present invention.

Here, FIG. 4 is a partial side sectional view of a paper feeding device of a copying machine according to an embodiment of the present invention, FIG. 5 is a sectional view taken along the line A-A' in FIG. 4, and FIGS. The diagram is
FIG. 6 shows a partial side cross-sectional view of a paper feeding device of a copying machine according to another embodiment of the present invention.

Note that the same reference numerals are used to describe the same elements as those used in FIGS. 1 to 3.

As shown in FIG. 4, a shaft 18 is fixed to the main body of the copying machine in addition to the shaft 16 of the paper feed roller 13 above the copy paper 12 stored in the paper feed cassette 9. A presser guide 15a made of a plate material or the like is attached to the shaft 18 so as to be swingable around the shaft 18.

A hole 19 having a diameter sufficiently larger than the diameter of the shaft 16 is provided approximately at the center of one end (the left side in FIG. 4) of the presser guide 15a.
A shaft 16 is loosely fitted into the shaft 9, so that the holding member 15a can swing vertically about the shaft 18.

A locking hole 20 is provided at the other end of the presser guide 15a (the right side in FIG. 4), and a lower end of a spring 21 whose upper end is fixed to the main body of the copying machine is attached to the locking hole 20. It is being Therefore, this spring 21 moves the presser guide 15a to the shaft 18.
The structure is such that it is rotated and biased counterclockwise in FIG. 4 around , and brought into contact with the uppermost layer of copy paper 12 stored in the paper feed cassette 9 and presses it downward. In addition, such a presser foot guide 15a
are provided on the bent portion of the copy paper 12 shown in FIG. 3, and are further provided symmetrically in a plurality of pairs in the width direction as shown in FIG. For example B4
In the case of a copying machine that can accommodate two types of paper feed cassettes, A4 size and A4 size, a pair of left and right holding guides 15a, 1 on the rightmost and rightmost sides in FIG.
5a is provided at a position corresponding to the width of a B4 size paper, and a pair of presser guides 15a, 15a located one position inside thereof can be set to correspond to an A4 size paper. The innermost (center) pair of holding guides 15a, 15a are
Regardless of the paper size, the center part of the copy paper stored in the paper feed cassette is held down to prevent the copy paper from bulging over time. However, when the copy paper 12 is bent, the biasing force of the presser guide 15a by the spring 21 depends on the rigidity of the copy paper,
The force is set to be so slight that the presser guide can be lifted to an appropriate height by an upward force determined by the thickness and the like.

Next, the operation of the above embodiment will be explained in more detail.

The copy paper 12 stored in a stack in the paper feed cassette 9 is pressed against the paper feed roller 13 by a push-up member 22 made of a spring or the like provided at the bottom thereof, and the paper feed roller 13 is moved clockwise. When the copy paper 12 in the uppermost layer contacts the paper feed roller 13, it attempts to move in the take-out direction shown by arrow G in FIG. Since the copy paper 12 is held with a slight force, a buckling force acts on the copy paper 12, and its front edge 12' begins to bend upward. However, since the copy paper 12 is pressed downward by the presser guide 15a urged by the spring 21 as described above, the copy paper 12
When the bending strength of the copy paper 12 is large (in the case of stiff paper, thick paper, etc.), the presser foot guide 15a is lifted to a height position corresponding to the bending strength of the copy paper 12. .

Therefore, if the bending strength of the copy paper 12 is large, the presser guide 15a will be pushed up accordingly and the bending radius will be increased, but if the bending strength of the copy paper 12 is small, the presser guide 15a will be pushed up accordingly and the bending radius will become larger. This is the bending radius.
Generally, if the guide bending radius is small, the buckling force becomes large, but on the other hand, frictional force, electrostatic force, etc. The adsorption force exerted by the above does not change significantly. Therefore, as described above, as a result of the bending radius that occurs in the top layer of copy paper 12 changing depending on the bending strength of the copy paper, the bending radius of the top layer of copy paper 12 changes from the second sheet from the top. The accompanying bending force is not transmitted, and in the end, only the uppermost copy paper 12 is bent, separated from the second and subsequent copy papers 12, and taken out from the cassette 9.

The bending radius of the copy paper 12 changes as described above depending on the inherent bending strength of the copy paper 12, so even if the copy paper 12 has a different bending strength, it will automatically move from the paper feed cassette 9 to the paper feed cassette 9.
The sheets are taken out one by one without any bending.

Note that even when the amount of copy paper 12 stored in the paper feed cassette 9 is small, the presser guide 15a cannot be lowered below a certain position because the shaft 16 passes through the hole 19 of the presser guide 15a. There isn't.

Another embodiment of the present invention is shown in FIGS. 6 and 7. As shown in FIG.
It is also possible to fit the copy paper 12 in a vertically movable manner and to adjust the position of the presser in the vertical direction by adjusting the weight of the presser guide 15b. In this case, the spring 21 and the shaft 18 as in the above-mentioned embodiments are not required, so there is an advantage that the device is simple.

In the embodiment shown in FIG. 7, a presser guide 15c is swingably supported by a shaft 18', and its tip 23 presses the copy paper 12. The presser force in this case is determined by adjusting the weight and length of the presser guide 15c. Shoshaft 2
4 is a stopper to prevent the presser guide 15c from lowering too much.

As described above, the present invention presses the paper feed roller against the top surface of the copy sheets stacked in the paper feed cassette, rotates the paper feed roller, and sends out the top layer of copy paper from the paper feed cassette. ,
By hooking the front edge of the fed-out copy paper to the separating claw and feeding it out, the front edge of the copy paper is bent, and the top layer of copy paper is separated from the second and subsequent layers of copy paper before being sent out. In the paper feeding device of the copying machine, a plurality of pairs of presser guides symmetrically provided above the bent portion of the copy paper are movable in the vertical direction by the repulsive force of the bent copy paper for copying. Since the copying machine paper feeding device is supported in a fixed position on the machine body side, if the material or thickness of the copy paper changes and its bending strength changes, the The vertical position of the presser guide relative to the copy paper changes depending on the type, so the copy paper can be reliably separated one by one without excessive bending of the copy paper taken out from the paper cassette. can be supplied to the next process.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of an example of a conventional copying machine, Fig. 2 is a perspective view of the paper feeding device of the copying machine, Fig. 3 is a partial sectional view of the paper feeding device, and Fig. 4 is a cross-sectional view of the paper feeding device of the copying machine. A partial side cross-sectional view of a paper feed device of a copying machine according to an embodiment, No. 5
The figure is a cross-sectional view taken along the line A-A' in Fig. 4.
7 and 7 show partial cross-sectional views of a paper feeding device of a copying machine according to another embodiment of the present invention. Brief explanation of symbols, 9...Paper feed cassette, 12
...Copy paper, 12'...Front edge, 13...
Paper feed roller, 14...Separation claw, 15a, 15b,
15c...Presser guide, 17...front edge.

Claims (1)

[Scope of utility model registration request] When the paper feed roller is pressed against the top surface of the copy paper stacked in the paper feed cassette and the paper feed roller is rotated to send out the top layer of copy paper from the paper feed cassette, the front side of the copy paper being sent out is A feeder for a copying machine in which the front edge of the copy paper is bent and the top layer of copy paper is separated from the second and subsequent layers of copy paper before being sent out by feeding the copy paper while hooking the edge on a separation claw. In the paper device, a plurality of pairs of presser guides symmetrically provided above the bent portion of the copy paper are held at a fixed position on the copying machine main body side in a state where they can be moved vertically by the repulsive force of the bent copy paper. A paper feeding device for a copying machine characterized by being supported.