JP2003321138A - Paper sheet feeder, and image-forming device provided therewith - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To minimize the occurrence of unusual noise and double feed due to its small size, no generation of abnormal noise, and excellent durability. A separation member having a sheet feeding device and a sheet feeding roller for feeding a sheet material in contact with a bottom plate, and an inclined surface with which a front end of the sheet material fed by the sheet feeding roller abuts. 5 are provided, and a plurality of grooves 14 are formed on the outer peripheral surface of the paper feed roller 4 along the roller axis direction in the circumferential direction of the roller. The groove 14 increases the sheet feeding / conveying force, thereby improving the sheet material separation performance. Further, the paper dust generated from the sheet material and adhered to the outer peripheral surface of the paper feed roller enters the groove 14 of the paper feed roller 4, so that it is possible to prevent the paper feed roller 4 from slipping due to the influence of the paper dust. it can.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus for feeding sheet materials fed by a sheet feeding roller by separating them one by one by a separating member having an inclined surface, and a facsimile apparatus and a printer including the same. , An image forming apparatus such as a copying machine.

[0002]

2. Description of the Related Art Conventionally, in a sheet feeding device for separating a stacked sheet material from an uppermost sheet material positioned at the top one by one and feeding the separated sheet material to an image forming section, Corner claw separation method that separates both widthwise ends at the front end in the feeding direction with claw members, separation pad method that separates the sheet material by pressing the friction member, abut the sheet material on a separation member having an inclined surface There is a bank separation method (see, for example, Japanese Patent Application Laid-Open No. 10-139197) for separating by separating. Of these, a wide variety of sheet materials (for example, postcards, envelopes,
A separation method applicable to OHP paper etc. is a separation pad method.

[0003]

However, such a separation pad system is particularly useful for low-priced low-speed machines whose sheet feeding and printing speeds are as slow as a linear velocity of 200 mm / sec or less.
The sheet material sandwiched between the paper feed roller and the friction member is liable to cause abnormal noise due to sticking slip during transportation. Therefore, in the case of such a low-speed machine, there is a case where a mechanism for releasing the contact between the sheet feeding roller and the friction member (releasing the nip) after separating the sheet material may be required. Therefore, there is a drawback that the number of parts increases correspondingly and the cost increases. Further, in such a separation pad method, when a member having a large friction is used as the friction member, if the sheet material is curled or the cutting surface has burrs, the tip of the sheet member is caught by the friction member and a feed failure occurs. It was easy to do. Further, in the case of the separation pad system, it is necessary to bring the paper feed roller into contact with the pad surface of the friction member and the sheet material at the same time, and the conveying direction of the sheet material sent out from the stacking position (sheet material stacking such as bottom plate stacking). (Corresponding to the displacement angle of the member), the separation performance cannot be obtained unless the angle of the separation pad is within a predetermined range. Therefore, since the diameter of the paper feed roller is limited, the degree of freedom in layout is restricted, which makes it difficult to downsize the paper feed device.

Furthermore, the sheet feeding roller continues to rotate while being in contact with the friction member until the sheet material fed from the sheet stacking section reaches the separation section provided with the friction member. In some cases, the paper feed roller and the friction member (separation member) are more easily worn than other separation systems. As a result, there has been a problem that the paper feed roller and the friction member are greatly deteriorated with time (abrasion) and durability is deteriorated.
Further, there is a problem that the paper feed roller is apt to deteriorate over time due to the paper dust adhering to the paper feed roller. The present invention has been made in view of the above problems, and is excellent in durability without causing abnormal noise, is small in size, and is reliable one by one without causing non-feeding or double feeding. An object of the present invention is to provide a sheet feeding device that can separate and feed sheets and an image forming apparatus including the same.

[0005]

In order to achieve the above object, the present invention provides a sheet feeding roller which comes into contact with a sheet feeding front end side of a sheet material stacked in a sheet stacking section and feeds the sheet material, A separating member that is arranged so as to contact the outer peripheral surface of the sheet feeding roller and has an inclined surface against which the front end of the sheet material fed by the sheet feeding roller abuts; In the paper feeding device in which the sheets are separated one by one, a plurality of grooves along the roller axial direction of the paper feeding roller are formed on the outer circumferential surface of the paper feeding roller in the circumferential direction of the roller. When the groove width of the groove in the circumferential direction of the sheet feeding roller is A and the contact surface width of the contact surface of the separating member with the sheet feeding roller in the sheet material feeding direction is B, the relationship of A <B is satisfied. It is good to do so. Further, the outer peripheral surface of the sheet feeding roller, which abuts the separating member, may be formed in a grain shape.
Further, there is also provided an image forming apparatus including any one of the above-described paper feeding devices.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged view showing a configuration of a portion for separating a sheet material of a sheet feeding device according to an embodiment of the present invention, FIG. 2 is a schematic configuration diagram showing the vicinity of a sheet feeding roller of the sheet feeding device, and FIG. FIG. 1 is an overall configuration diagram showing an example of an image forming apparatus similarly provided with the paper feeding device. In the copying machine which is the image forming apparatus shown in FIG. 3, the optical writing system 33 is provided in the image forming system 34 based on the image data read by the optical reading system 32 provided in the copying machine main body 31. A latent image is formed on the photosensitive drum 35, and the latent image is made visible by the developing device 36 of the image forming system 34 using toner. A sheet feeding device 1 is provided below the copying machine main body 31, and a sheet material P, which is a recording sheet fed from the sheet feeding device 1, is conveyed through a conveying path 37 by a conveying roller pair 7 to form an image forming system. 34, where a visible image (toner image) on the photosensitive drum 35 is reached.
Is transcribed.

The sheet material P on which the visible image is transferred is conveyed to a fixing device 38 where the visible image is fixed, and
The sheet is discharged to an external sheet discharge tray 40 by the sheet discharge roller pair 39. Further, at the time of double-sided image formation, the sheet material P is moved from the reversing conveyance path 41 to the double-sided device 42 by a sheet discharging branching claw (not shown).
Is conveyed to the double-sided tray 43, is temporarily stored in the double-sided tray 43, and then the traveling direction is reversed. The paper is discharged onto the paper tray 40. Although only one sheet feeding device 1 is shown in FIG. 3 for simplification of the drawing, it is possible to provide a plurality of sheet feeding devices of different sizes as needed. Further, the image forming apparatus having the paper feeding device is not limited to the copying machine, and can be applied to a facsimile, a printer, etc. without any trouble.

As shown in FIG. 2, the sheet feeding device 1 has a bottom plate 2 which is a sheet stacking unit, and the bottom plate 2 is rotated in the direction of arrow A with its left end portion as a fulcrum in the figure. It is movable. The paper feeding device 1 includes a paper feed roller 4 that comes into contact with the upper surface of the sheet material P stacked on the bottom plate 2 on the leading edge side (right side in FIG. 2) to feed the sheet material P, and the paper feeding roller 4. Laura 4
Is arranged so as to abut the outer peripheral surface of the sheet feeding roller 4
And a separating member 5 having an inclined surface 5a against which the front end of the sheet material P fed by the above is abutted, and the separating member 5 separates a plurality of sheet materials P one by one. The paper feed roller 4 is supported by the paper feed housing 3 so as to be rotatable in the direction of arrow G. Further, the separating member 5 has a fulcrum 13
Is rotatably supported in the direction of arrow C around
The lower surface of the separating member 5 is pressed by the separating pressure spring 12, and the separating member 5 is brought into contact with the outer peripheral surface of the sheet feeding roller 4 as shown by the urging force of the separating pressure spring 12.
The position can be decided. Paper feed roller 4
Is a groove (knurled groove) along the roller axis direction (the direction from the front side to the back side in the figure) on the outer peripheral surface as shown in FIG.
A plurality of 14 are formed in the circumferential direction of the roller indicated by arrow E.
The circumferential groove width of each groove 14 is A, and the separating member 5
When the contact surface width of the contact surface 5b with the sheet feeding roller 4 in the sheet feeding direction is B, the relation of A <B is satisfied.

In the sheet feeding device 1 shown in FIG. 2, when the sheet can be fed, the sheet material P stacked on the bottom plate 2 rises with the end portion on the left side in the figure as a fulcrum. By being urged to rotate to the side, the leading edge side of the sheet feed contacts the sheet feed roller 4 at a predetermined sheet feed pressure as shown in the figure. Here, when the paper feed roller 4 is rotated in the arrow G direction, the uppermost sheet material P is fed toward the separating member 5. Then, when a plurality of sheet materials P are fed between the separating member 5 and the paper feed roller 4, they are separated one by one, as shown in FIG.
The paper is fed to the conveyance path 37 shown in FIG. The paper feed roller 4
Must be in contact with the upper surface of the sheet material P and the contact surface 5b of the separating member 5 at the same time.

By the way, as described above with reference to FIG. 1, the paper feeding device 1 has a plurality of grooves 14 formed in the outer circumferential surface of the paper feeding roller 4 along the roller axial direction in the circumferential direction of the roller. Therefore, as shown in FIG. 4, the groove width A of the groove 14 has a relationship of A> B with the contact surface width B of the contact surface 5b of the separating member 5'with the sheet feeding roller 4 '. If you
When the paper feed roller 4'is rotated, the separation pressure spring 1 is provided on the outer peripheral surface thereof.
The portion of the contact surface 5b of the separating member 5'which is pressed by the urging force of 2 (a pressing force capable of obtaining a predetermined separating pressure) bites into the groove 14 of the sheet feeding roller 4'as shown in the drawing. become. As a result, the separating member 5'blocks the paper passage. If this happens, the sheet material will not be fed smoothly, which may result in feeding failure. Further, after the portion of the separating member 5 ′ on which the contact surface 5 b is formed bites into the groove 14 of the sheet feeding roller 4,
When it is repelled by the rotation of the paper feed roller 4'and comes out of the groove 14, the paper feed roller 4'is momentarily formed in a slight gap between the separating member 5'and the outer peripheral surface of the paper feed roller 4 '. Therefore, there is a possibility that the sheet material sent out by the above may get in, and the sheet material may be fed as it is, resulting in a separation failure.

However, in this paper feeding device 1, the groove 1
Since the relationship between the groove width A of 4 and the contact surface width B is A <B as shown in FIG.
The abutting surface 5b does not enter the groove 14 of the sheet feeding roller 4 and bite into it. Therefore, it is possible to prevent the sheet feeding failure of the sheet material and the separation failure of the sheet material. Further, since the plurality of grooves 14 formed on the outer peripheral surface of the sheet feeding roller 4 serve to increase the sheet feeding / conveying force (grip force for the sheet material), the separation performance of the sheet material can be improved. Further, even if the paper dust generated when the sheet material is separated adheres to the outer peripheral surface of the paper feed roller 4, the paper dust will be accumulated in the groove 14 of the paper feed roller 4. Therefore, it is possible to prevent a sheet feeding failure due to the slip of the sheet, which is likely to occur when the paper dust adheres to the surface of the sheet feeding roller.

FIG. 5 is an enlarged view partially showing an example of a paper feed roller having an outer peripheral surface having a grain shape. This paper feed roller 4 "
Has a wrinkle 15 formed over the entire outer peripheral surface that abuts the separating member 5 (see FIG. 1), and the entire outer peripheral surface except the groove 14 has a wrinkle shape. In this way, if the paper feeding roller 4 ″ having the embossed surface 15 formed on the outer peripheral surface thereof is used and a paper feeding device similar to the paper feeding device 1 described in FIG. It becomes difficult for paper powder to adhere to the outer peripheral surface of the ″. Further, since the paper dust also escapes in the valleys of the grain 15, it is possible to maintain a stable paper feed and conveyance force. This makes it possible to obtain a stable sheet feeding and conveying force over time and improve durability performance.

[0013]

As described above, according to the sheet feeding apparatus of the present invention, the separating member for the sheet material is provided with the separating member having the inclined surface against which the front end of the sheet material is abutted, without providing the friction member. With such a configuration, it is possible to prevent generation of abnormal noise. Further, since the structure is simple, the device can be downsized. Further, since a plurality of grooves are formed on the outer peripheral surface of the sheet feeding roller along the roller axis direction, the sheet feeding / conveying force is increased by that amount, so that the separation performance of the sheet material can be improved. Further, the paper dust generated from the sheet material and adhering to the outer peripheral surface of the paper feed roller enters the groove of the paper feed roller, so that the paper dust continues to adhere to the surface of the paper feed roller in contact with the separating member. Since it does not occur, it is possible to prevent the paper feed failure due to the slip of the paper feed roller which is likely to be caused by the paper dust.

[Brief description of drawings]

FIG. 1 is an enlarged view showing a configuration of a portion for separating a sheet material of a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing the vicinity of a sheet feeding roller of the sheet feeding device.

FIG. 3 is an overall configuration diagram showing an example of an image forming apparatus similarly provided with the paper feeding device.

FIG. 4 is an enlarged schematic view showing a state in which a contact surface portion of a separating member enters into a groove of an outer peripheral surface of a sheet feeding roller and bites into the groove.

FIG. 5 is an enlarged view showing a partially enlarged example of a paper feed roller whose outer peripheral surface is embossed.

[Explanation of symbols]

1: Paper feeding device 2: Bottom plate (sheet stacking unit) 4: Paper feed roller 5: Separation member 5a: inclined surface 5b: contact surface 14: Groove 15: Texture

Claims (4)

[Claims] 1. A sheet feeding roller that comes into contact with the leading edge side of a sheet material stacked in a sheet stacking section and feeds the sheet material, and is arranged so as to contact an outer peripheral surface of the sheet feeding roller. ,
And a separating member having an inclined surface with which a front end of the sheet material fed by the sheet feeding roller abuts, and a plurality of sheet materials are separated one by one by the separating member. A sheet feeding device characterized in that a plurality of grooves are formed on the outer peripheral surface of the paper roller along the roller axial direction of the sheet feeding roller in the circumferential direction of the roller. 2. When the groove width of the groove in the circumferential direction of the paper feed roller is A, and the contact surface width of the contact surface of the separating member with the paper feed roller in the sheet material feed direction is B, 2. The sheet feeding device according to claim 1, wherein the relationship of A <B is established. 3. The paper feeding device according to claim 1, wherein an outer peripheral surface of the paper feeding roller that abuts on the separating member is formed in a grain shape. 4. An image forming apparatus comprising the sheet feeding device according to claim 1.