JPH0672563A - Paper feeding device - Google Patents

Abstract

PURPOSE:To provide a paper feeding device which makes an installation area small, reduces cost, and improves separation performance of recording paper by providing a separation means which separates recording paper which is over-lapped when paper is fed and a buckling prevention means which prevents flexure and deformation in the direction of thickness of recording paper set in longitudinal direction. CONSTITUTION:Prevention of buckling of a bundle of recording paper 2 which is stored in a cassette in longitudinal direction is done by a vertical bottom plate 13 which is pressed by a spring 12 and a buckling prevention facing pressing plate 14 which also serves as a guide of recording paper. The recording paper 2 is conveyed by a pick up roller 10. The separation motion which separates the first sheet of two sheets of the recording paper 2 which are sent while overlapped from the second sheet is done by pressing force in the direction of thickness from the bottom plate 13 which is roughly vertical and pressed by the spring 12 in a cassette 1 in cooperation with stiffness of the recording paper 2 which is pressed against a separation claw 11 provided at a corner in upper fringe of the cassette 1 due to pressing force. Consequently, it is possible to make it compact, reduce cost, and improve performance without increasing cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a paper feeding device for handling standard paper such as a copying machine, a facsimile, a printer and a recording device.

[0002]

2. Description of the Related Art In a conventional cassette type paper feeder which uses standard papers such as A series and B series as recording papers,
Since the recording paper is loaded horizontally (horizontally) and set, the installation area of the apparatus is increased, and it is impossible to make the area at least smaller than the area of the recording paper. In the image forming apparatus equipped with a paper feeding device, the installation area of the paper feeding device should be smaller than the area of the recording paper even though the demands for downsizing and space saving of machines are increasing. Therefore, there is a problem in that the area occupied by the paper feeding device cannot be made smaller than the size of the recording paper loaded horizontally (horizontally).

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and by setting the recording paper vertically with respect to the horizontal plane, the contact area can be reduced, the cost can be reduced, and the separation performance of the recording paper can be improved. It is an object of the present invention to provide a sheet feeding device designed.

[0004]

In order to achieve the above-mentioned object, the present invention provides a vertical feeding device for setting recording paper in a vertical type, a separating means for separating the double fed recording paper, and a vertical means. A buckling prevention means for preventing deformation of the recording paper set in the mold in the thickness direction, and the separating means is a separation claw at an upper edge corner portion of a paper feed cassette for accommodating the recording paper. The separation means is a pair of separation pads for separating the recording paper conveyed in the double feed state, and the separation means is a friction separation for separating the recording paper conveyed in the double feed state. It is characterized in that it is a roller pair, and one of the friction separation roller pairs is reversed to separate the multi-feed recording paper.

[0005]

According to the paper feeding apparatus constructed as described above, the recording paper is set in the vertical type, and the separating means for the recording paper and the buckling preventing means are combined, so that the conventional paper feeding apparatus. Thus, it is possible to provide a paper feeding device that is smaller in size, lower in cost, and improved in separation performance of recording papers without increasing the cost.

[0006]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic configuration explanatory view of a laser printer which is a recording device to which the paper feeding device of the present invention is applied. This recording device is a vertically long device with a small contact area with the floor surface, and has a vertically long structure. In order to do so, a characteristic is that the paper feed cassette 1 is housed in a vertical type (substantially perpendicular to the floor surface). Recording papers 2 (for example, standard papers of A series and B series) accommodated vertically in a cassette 1 are sequentially fed toward a separating means 3 as indicated by an arrow, and an image forming unit inside the recording apparatus is formed. Be transported to. That is, when the recording paper 2 taken out by the pickup roller 10 is in the double feeding state, the separating means 3 separates the overlapping recording papers and feeds only one sheet. The transfer unit 4 transfers the toner image formed on the photoconductor 5 onto the recording paper 2 fed by the registration roller 4a. In the laser unit 6, optical writing is performed on the photoconductor 5 that is uniformly charged in advance to form an electrostatic latent image. In the developing unit 7, toner is attached to the electrostatic latent image on the photoconductor 5. In the fixing unit 8, the toner image transferred by the transfer unit 4 is fixed, and the recording paper 2 is stacked on the paper discharge tray 9.

FIG. 2 is an explanatory view of the essential structure of the sheet feeding device of the present invention, and FIG. 3 is an explanatory view of the structure of the separation claw part. In FIG. 2, the recording paper 2 is conveyed by the pickup roller 10. The first of the two recording papers 2 in the double feed state
The separating operation for separating the first recording sheet is performed by pressing the recording sheet 2 from the substantially vertical bottom plate 13 pressed by the spring 12 in the main body of the cassette 1 in the thickness direction and the cassette 1 by the pressing force. It is realized by cooperation with the waist of the recording paper 2 which is pressed against the separation claw 11 provided at the upper edge corner. Separation claw 1
The operation of 1 is well known and will not be described in detail here. A driving force is intermittently transmitted to the pickup roller 10 by a clutch such as an electromagnetic clutch or solenoid (not shown), and the half-moon-shaped pickup roller 10 makes one rotation to feed the recording paper 2 at the pickup portion. The operation is completed. The conveyance by the pickup unit is not limited to such a form, and it is not necessary to limit to the half-moon roller as long as the drive can be transmitted intermittently to the recording paper 2.

A vertical bottom plate 13 which is pressed by a spring 12 prevents buckling of a bundle of recording papers 2 which are vertically accommodated in the cassette 1 (bending in the thickness direction, deformation such as bending). And buckling prevention presser plate 14 that also functions as a guide for recording paper
This is performed by preventing the buckling prevention means consisting of (1) and (2) from deforming the recording paper 2 set in the vertical direction in the thickness direction. The spring 12 may be inserted from the outside of the main body of the cassette 1, and the pressing force of the bottom plate 13 may be reduced for a short time to take out the recording paper 2 by rotating the pickup roller 10. In order to reduce the friction with the buckling prevention counter pressing plate 14 which also functions as a recording paper or a guide, the bottom plate is locked against the spring 12 for a short time by an arm or the like operated by a drive device (not shown). May be. Further, the height of the buckling prevention counter pressing plate 14 that also serves as a guide may be changed according to the size of the standard paper.

Since the recording paper 2 is set vertically as described above, the load on the separating means can be small, so that a small drive motor (not shown) can be used, which leads to cost reduction. The entire device can be downsized. Further, since the recording paper 2 is set vertically, the frictional force between the recording papers is reduced and the separation performance is improved.

FIG. 4 is a side sectional view of a sheet feeding device according to another embodiment of the present invention. In FIG.
Are conveyed by the pickup roller 10. Chart paper 2
The separation operation for separating the second recording paper from the second recording paper is performed by the feed roller 15 and the pair of separation pads 17 attached to the separation pad support 16 which is a friction plate. The double-fed recording paper is pressed against the feed roller 15 by the pressure spring 22 with a constant load, and has a high friction coefficient, so that the second and subsequent recording papers can be prevented from entering. Other buckling prevention means and the like are the same as those described above, and will be omitted.

FIGS. 5 and 6 (a) and 6 (b) are a structural explanatory view and a principal structural explanatory view of a sheet feeding device according to another embodiment of the present invention.
In the figure, as in the above, the recording paper 2 is conveyed by the half-moon shaped pickup roller 10. The separation operation for separating the recording paper 2 from the next second recording paper is performed by the torque limiter 20 mounted on the separation shaft 19 on which the separation roller 18 is mounted in the separation roller 18 and the feed roller 15 pair. This is performed by preventing the second and subsequent sheets of recording paper from entering due to the returning force in the reverse direction (arrow B direction) that occurs (see FIG. 6A). That is, the torque limiter 20
Is a return force in the reverse direction B when the rotational torque in the conveying direction (forward direction) indicated by the arrow A exceeds a predetermined value when the double-fed recording paper is passed, and the forward torque is cut off. Is generated.

Alternatively, the separation roller drive shaft 21 on which the separation roller 18 and the torque limiter 20 are mounted is driven to rotate in the reverse direction indicated by the arrow B by a drive source (not shown). The reverse rotation of 18 may prevent the second and subsequent recording sheets from entering (see FIG. 6 (b)). The configuration and operation of the other buckling prevention means and the like are the same as those described above, and will be omitted.

[0013]

Since the present invention is constructed as described above, the cost of the recording sheet set in the vertical direction, the combination of the separating means and the buckling preventing means can be reduced as compared with the conventional sheet feeding device. It is possible to provide a sheet feeding device that is downsized without increasing the cost, and has improved recording paper separation performance.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a schematic configuration of a recording device to which a paper feeding device of the present invention is applied.

FIG. 2 is a side sectional view of a sheet feeding device showing an embodiment of the present invention.

FIG. 3 is an enlarged explanatory view of a separation claw provided at an upper edge corner of the cassette of FIG.

FIG. 4 is a side sectional view of a paper feeding device showing another embodiment of the present invention.

FIG. 5 is a side sectional view of a paper feeding device showing another embodiment of the present invention.

6 (a) and 6 (b) are an enlarged perspective view of a main part of FIG. 5 and an enlarged perspective view of another main part of FIG.

[Explanation of symbols]

1 ... Cassette, 2 ... Recording paper, 3 ... Separation means, 4 ... Transfer unit, 5 ... Photoconductor, 6 ...
Laser unit, 7 ... Developing unit, 8 ... Fixing unit, 9 ... Paper ejection tray, 10 ... Pickup roller, 11 ... Separation claw, 12 ... Spring,
13 ... Bottom plate, 14 ... Buckling prevention counter pressing plate, 15
... Feed rollers, 16 ... Separation pad cradle, 1
7 ... Separation pad, 18 ... Separation roller, 19 ...
Separation shaft, 20 ... Torque limiter, 21 ... Separation roller drive shaft, 22 ... Pressure spring.

Claims (5)

[Claims] 1. A vertical feeding apparatus for feeding one by one from a stack of recording sheets set vertically, and a separating means for separating the recording sheets that have been double fed at the time of feeding, and a recording set in the vertical type. A sheet feeding device comprising: buckling prevention means for preventing flexural deformation of the paper in the thickness direction. 2. The sheet feeding device according to claim 1, wherein the separating unit is a separating claw at an upper corner portion of a sheet feeding cassette that accommodates the recording sheet. 3. The paper feeding device according to claim 1, wherein the separating means is a pair of separation pads for separating the recording papers conveyed in a double feed state. 4. The paper feeding device according to claim 1, wherein the separating means is a friction separation roller pair that separates the recording papers conveyed in a double feed state. 5. The paper feeding device according to claim 4, wherein one of the pair of friction separating rollers is reversed to separate the multi-fed recording paper.