JP3072784B2 - Image forming apparatus provided with separation feeding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a separating and feeding device, and more particularly, to an image forming apparatus such as a printer, a copying machine, a printing machine, etc. The present invention relates to a separating and feeding apparatus for sequentially feeding paper sheets from the highest order or the lowest order.

[0002]

2. Description of the Related Art FIG. 6 shows a schematic configuration example of a conventional image forming apparatus. FIG. 6 shows an image forming apparatus to which an electrophotographic process is applied. Reference numeral 501 denotes a paper feed roller, 502 denotes a paper separating mechanism, which is in contact with the paper feed roller 501 by an elastic support (not shown). Separated by friction, 1 from top
Feed them one by one. Reference numeral 503 denotes a static elimination needle (also referred to as a static elimination brush) for removing charges on the transfer surface (image forming side) of the sheet 518 before image transfer. Paper separation mechanism 502 and static elimination needle 5
03 is grounded by the grounding circuits 504, 506, and 507 via the main body chassis 509. 510, 51
1 is a paper conveyance guide plate, and 512 is a paper conveyance auxiliary roller. When the paper conveyance path is determined to be difficult due to a sharp curve,
It is added as needed. Reference numerals 513 and 514 denote registration rollers which remove skew of the paper and align the leading edge of the paper before image transfer. 515 is a photosensitive drum to which an electrophotographic process is applied, 516 is a transfer roller, and an image is transferred between 515 and 516 onto a paper surface. Thereafter, the printed paper sheet is discharged outside through a fixing process (not shown) of the transferred image. 508 is a main frame on which each mechanism is mounted.

[0003] These series of operations are extremely smooth,
In particular, in the paper feeding / separation mechanism, it is essential that the noise does not occur, such as generation of abnormal noise, damage to the transfer surface, and application of vibration to the transfer surface during transfer.

[0004]

However, in the above-mentioned conventional example, the following problem occurs because the fixing method of the paper separating mechanism has a play in the paper feeding direction. That is, as shown in FIG. 7, rotation of the paper sheet in the feeding direction occurs at the same time as the movement of the paper feeding roller in the contact direction, and the paper separating mechanism tilts and deviates from the proper contact position. Became. As a result, (1) the paper separation mechanism repeatedly vibrated during the transfer, repeatedly tilting and restoring, causing irregularities in the transferred image such as pitch unevenness and image rubbing. (2) Due to the same factors as in (1) above, the frictional surface between the separation mechanism and the paper sheet during the transport of the paper sheet (including during transfer)
A fricative sound was generated. (3) The contact force of the paper feed roller is reduced,
Trouble such as paper jam (jam) caused by double feeding occurred. (4) Due to the inclination of the paper separating mechanism, the paper feed roller and the corner edge of the separating mechanism come into contact with each other and bite the paper sheets. Caused troubles such as breakage.

[0005]

According to the present invention, there is provided a sheet feeding roller for feeding a sheet, and a sheet provided to be in contact with the sheet feeding roller for separating the sheet between the sheet feeding roller. An image forming apparatus comprising: a sheet separating unit that abuts a sheet feed roller and supports a separating unit that separates a sheet; and a belly that supports the head. A sliding portion provided on the downstream side in the sheet feeding direction of the separating means and slidably in contact with the head, and guiding the sheet separating means to move in a direction of contacting or separating from the sheet feeding roller; It is characterized by. Further, the present invention includes a sheet feeding roller for feeding a sheet, and sheet separating means provided so as to be in contact with the sheet feeding roller and separating the sheet between the sheet feeding roller. The image forming apparatus according to claim 1, further comprising rolling means for slidingly contacting the sheet separating means and guiding the sheet separating means to move in a direction parallel to a direction in which the sheet separating means contacts the sheet feeding roller.

[0006]

FIG. 1 shows a first embodiment of the present invention.
And FIG. In this embodiment, 101 is a paper feed roller for feeding out a sheet, 102 is a paper separation mechanism that is provided so as to be able to contact or separate from the paper feed roller 101 and separates paper sheets. (Not shown) is in contact with the paper feed roller 101. The paper separating mechanism is in contact with the paper feed roller and has a head 102 having a sheet separating portion.
a and an abdomen 102b supporting the head 102a. Reference numeral 103 denotes a paper separating mechanism for the paper feed roller 1.
It is a sliding member as a sliding portion that regulates movement in a direction in which it comes into contact with or separates from 01. Reference numeral 104 denotes a static elimination needle.

In this embodiment, as shown in FIG. 2, the head 102a of the paper separating mechanism 102 comes into contact with the sliding member 103 while the paper S is being fed. The paper feed roller 101 slides in a direction away from the paper feed roller 101 by the thickness of the paper along the contact direction between the paper feed roller 101 and the paper separating mechanism 102, and feeds the paper during paper conveyance (including image transfer). Rotational movement due to rotational force biased in the feeding direction is prevented.

The sliding member 103 is provided with a paper separating mechanism 102.
It is necessary to have good slidability without lubricating oil. For example, when the paper separating mechanism 102 is made of a resin material, the slidability is good if the sliding member 103 is made of a mirror-finished stainless steel plate or the like. .

(Other Embodiments) Another embodiment according to the present invention is shown in FIGS. 3, 4 and 5. FIG.
FIG. 3 shows an example in which a rolling member 303 is provided on a paper separating mechanism 301 and a rolling surface thereof is provided on a main frame 304. FIG. 4 shows a rolling member 403 and a paper separating mechanism 402 on a main frame 404.
In this case, the rolling surface is provided, and the operation is smoother than in FIG. The arrangement and number of the rolling members are not limited to those shown in FIGS.

FIG. 5 shows a state in which the head 703a and the abdomen 703b of the paper separating mechanism 703 are used as parts of the main frame 702 as sliding parts without providing the sliding member 103 in FIG.
In the case where the sliding surface 704 is used, it can be used when the conveying force of the paper sheet is a light load.

Incidentally, in each drawing of each embodiment, 105
~ 107, 305-307, 405-407, 705-
707 indicates ground circuits, respectively, 108, 304, 4
Reference numerals 04 and 702 denote main frames, respectively.
Indicates a main body chassis. The present invention is not limited to the above embodiments, and various modifications and configurations are possible.

[0012]

As described above, according to the present invention,
(1) Reduction of paper transport load, (2) Elimination of disturbance of a transferred image, (3) Removal of friction noise between sheet separating means and paper sheets,
(4) It is possible to reduce double feeding of paper sheets,
Smooth image formation can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an image forming apparatus embodying the present invention.

FIG. 2 is a diagram showing the operation of FIG. 1;

FIG. 3 is a diagram showing another embodiment according to the present invention.

FIG. 4 is a diagram showing another embodiment according to the present invention.

FIG. 5 is a diagram showing another embodiment according to the present invention.

FIG. 6 is a schematic sectional view of a conventional example.

FIG. 7 is a view showing the operation of the conventional example of FIG. 6;

[Explanation of symbols]

 101 paper feed roller 102/703 paper separation mechanism (sheet separation means) 102a / 703a head (sheet separation means) 102b / 703b abdomen (sheet separation means) 103/702 sliding member (sliding part) 104 static elimination needle 105 / 106/107 Grounding circuit 108 Main frame 109 Main body chassis 110/111 Paper transport guide plate 112 Conveyance auxiliary roller 113/114 Registration roller 115 Photosensitive drum 116 Transfer roller 117 Image forming apparatus main body 118 Sheet transport path

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Sugita 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References Japanese Utility Model 1987-47544 (JP, U) Japanese Utility Model Hei 2 −105933 (JP, U)

Claims (2)

(57) [Claims] 1. An image comprising: a sheet feeding roller for feeding a sheet; and sheet separating means provided so as to be in contact with the sheet feeding roller and for separating a sheet from the sheet feeding roller. In the forming apparatus, the sheet separating unit has a head supporting a separating unit that separates a sheet and abuts against a sheet feeding roller, and an abdomen supporting the head, and the sheet separating unit is configured to support the separating unit in a sheet feeding direction. A separating / feeding device provided with a sliding portion provided on the downstream side and slidably contacting the head, and guiding the sheet separating means to move in a direction of contacting or separating from the sheet feeding roller. An image forming apparatus comprising: 2. An image, comprising: a sheet feeding roller for feeding a sheet; and sheet separating means provided so as to be in contact with the sheet feeding roller and for separating a sheet from the sheet feeding roller. In the forming apparatus, there is provided a rolling unit that slides on the sheet separating unit and guides the sheet separating unit so as to move the sheet separating unit in a direction parallel to a direction in which the sheet separating unit contacts the sheet feeding roller. An image forming apparatus provided with the device.