JPH11338260A - Developing device for electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the smooth carrying of developer at high speed by providing a non-magnetic body member at interval of a specified value from the surface of a 2nd developing roller in the vicinity of a developer carrying magnetic pole provided on the back side of a regulating member for the 2nd developing roller. SOLUTION: The developing device is equipped with a non-magnetic body member 13 provided at interval of 3 mm to 10 mm from the surface of a developing roller 8 in the vicinity of the developer carrying magnetic pole (N2) provided on the back side of a regulating member 2 for the roller 8. The tip of the member 13 is arranged to be deviated by about >=2.5 deg. to an upstream side or a downstream side in the rotating direction of the developing roller with respect to the magnetic pole (N2). By providing the member 13 in such a way, the developer carried from the roller 8 to a developing roller 5 is regulated by the member 2, and the developer spilled and dropped on a paddle roller 9 without shifting to the roller 5 is received by the member 13, and the carrying amount of the roller 5 is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for an electrophotographic apparatus, and more particularly to a multi-stage developing roller type developing device for forming a visible image on a photosensitive member using a plurality of developing rollers. .

[0002]

2. Description of the Related Art FIG. In the figure, 1
Denotes a photosensitive drum rotatably supported in a direction indicated by an arrow;
Denotes a developing device. The developing device 12 is a device that develops a charge latent image recorded and formed on the photosensitive drum 1 and forms a developed image on the photosensitive drum 1.

A developing device 12 is provided opposite to the photosensitive drum 1, and is provided with a first developing roller 5 provided to rotate in the same direction as the rotation direction of the photosensitive drum 1. It is provided below the photosensitive drum 1 so as to oppose it,
A second developing roller 8 provided to rotate in a direction opposite to the rotation direction of the photosensitive drum 1 is provided near a position where the first and second developing rollers 5 and 8 are closest to each other. The regulating member 2 regulates the amount of the developer pumped up and distributes and supplies the developer to the developing rollers 5 and 8, a scraper 14, a paddle roller 9, an auger screw 10,
11 is comprised.

[0004] Developer 15 is auger screw 10,1
1, the amount of the developer flowing on the paddle roller 9 by the scraper 14 is regulated, and the amount of the developer transferred to the lower portion of the developing roller 8 by the paddle roller 9 is attracted by the fixed magnet 6 constituting the developing roller 8, so that the sleeve 7 Adheres to the surface of The adhered developer moves along the rotation direction of the sleeve 7 of the developing roller 8, the amount of the developer contributing to the development is regulated by the regulating member 2, and is conveyed to the development area to perform forward development. The agent 15 is returned to the stirring section by the paddle roller 9 again.

The developer 15 leaking from the regulating member 2 is attracted by the magnetic attraction of the fixed magnet 4 forming the developing roller 5.
The developer adheres to the developing roller 5 and moves along the rotational direction of the sleeve 3 of the developing roller 5 to regulate the developer amount of the developer 15 contributing to the reverse development by the regulating member 2 to perform the reverse development. .

Further, after the development is completed, the developer 15 flows down the upper surface of the scraper 14 and returns to the agitating section. Reference numeral 16 denotes a toner hopper, 17 denotes a toner feed roller, and 18 denotes toner.

[0007]

By the way, in the above-described developing device configuration, when the peripheral speed of the developing roller is increased in accordance with the increase in speed, the developing force from the developing roller 8 and the developing roller 5 is reduced only by the magnetic force of the developing roller 8 and the developing roller 5. When the developer is transferred to the roller 5, the transfer amount is not sufficient, and the amount of the developer that falls onto the paddle roller 9 increases, causing a conveyance failure on the developing roller 5 and adversely affecting the image quality. Had occurred. Therefore, when an attempt is made to improve the conveyance failure by increasing the amount of the developer on the paddle roller 9, the flow of the developer from the developing roller 8 to the paddle roller 9 is deteriorated, which causes a problem that the developing roller 8 is locked. I was

An object of the present invention is to provide a developing device of an electrophotographic apparatus capable of smoothly transporting a developer at a high speed.

[0009]

SUMMARY OF THE INVENTION The above object is achieved by a first photosensitive drum which is rotatably supported and is provided so as to rotate in the same direction as the photosensitive drum. A developing roller, a second developing roller provided below the first developing roller to face the photoconductor drum, and provided to rotate in a direction opposite to a rotation direction of the photoconductor drum; And a regulator provided near the closest position of the second developing roller to regulate the amount of the developer pumped up by the second developing roller and to distribute and supply the developer to the first developing roller and the second developing roller. A developing device of an electrophotographic apparatus comprising a member and a member, wherein a gap of 3 mm to 10 mm is formed with respect to the surface of the second developing roller near a developer carrying magnetic pole provided behind the regulating member of the second developing roller. Provided It is accomplished by providing a magnetic member.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. Members having the same configuration as in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

The developing device of the present invention is provided near the developer carrying magnetic pole (N2) provided behind the regulating member 2 of the developing roller 8 with a gap of 3 mm to 10 mm from the surface of the developing roller 8. It is characterized in that a non-magnetic member 13 is provided. Another characteristic is that the tip of the non-magnetic member 13 is displaced from the developer carrying magnetic pole (N2) by about 2.5 ° or more upstream or downstream in the rotation direction of the developing roller.

In FIG. 1, the non-magnetic member 13
Is arranged at a position shifted from the developer carrying magnetic pole (N2) by about 2.5 ° to the downstream side in the rotation direction of the developing roller.

By providing the non-magnetic member 13 in this manner, the developer conveyed from the developing roller 8 to the developing roller 5 is regulated by the regulating member 2, and cannot be transferred to the developing roller 5. The non-magnetic member 13 receives the falling developer, and the transport amount of the developing roller 5 can be secured.

FIG. 3 shows a configuration in which the tip of the non-magnetic member 13 is displaced from the developer carrying magnetic pole (N2) by about 2.5 ° on the upstream side in the rotation direction of the developing roller. The same effect as that of the configuration of FIG. 1 was obtained.

The magnetic poles of the developing roller 5 and the developing roller 8 are the same near the regulating member 2. Here, if the tip of the non-magnetic member 13 is temporarily attached to the transport magnetic pole (N
In the case where it is installed within 2.5 ° on the upstream side or the downstream side in 2), the developer receives a repulsive force due to the same polarity as the transport magnetic pole (N3) of the developing roller 5, and the developer is applied to the developing roller 5. It is difficult to move. Therefore, the non-magnetic member 13 is moved to the developing roller 8.
By setting the distance between the developing roller 8 and the tip of the non-magnetic member 13 to be 3 mm to 10 mm. , The amount of developer transferred to the developing roller 5 can be secured,
High image quality can be obtained. Further, the non-magnetic member 13
Is fixed to the scraper 14 in FIG. 1, but may be fixed to the casing of the developing device. Further, the non-magnetic member 13 has an effect of reducing the torque of the developing roller 8.

[0016]

As described above, according to the present invention, it is possible to provide a developing device of an electrophotographic apparatus capable of smoothly transporting a developer at a high speed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a developing device of the present invention.

FIG. 2 is a main part configuration diagram showing another embodiment of the developing device of the present invention.

FIG. 3 is a configuration diagram showing a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photoreceptor drum, 2 ... Regulatory member, 3,7 ... Sleeve,
4, 6: fixed magnet, 5, 8: developing roller, 9: paddle roller, 10, 11: auger screw, 12: developing device,
13: Non-magnetic member, 14: Scraper, 15: Developer, 16: Toner hopper, 17: Toner feed roller, 18: Toner

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yoshitaka Fujinuma 1060 Takeda, Hitachinaka City, Ibaraki Prefecture Inside Hitachi Koki Co., Ltd. (72) Inventor Yasuo Takuma 1060 Takeda Hitachinaka City, Ibaraki Prefecture Inside Hitachi Koki Co., Ltd.

Claims (2)

[Claims] A first developing roller provided to face a photosensitive drum rotatably supported and rotatably provided in the same direction as the rotating direction of the photosensitive drum; and a first developing roller. A second developing roller provided to face the photosensitive drum below the photosensitive drum, and provided to rotate in a direction opposite to a rotation direction of the photosensitive drum, and a closest approach position of the first and second developing rollers. A regulating member provided in the vicinity, for regulating the amount of developer pumped up by the second developing roller, and distributing and supplying the developer to the first developing roller and the second developing roller. In the developing device, a third developer roller is provided near the developer transporting magnetic pole provided behind the regulating member of the second developer roller.
A developing device for an electrophotographic apparatus, comprising a non-magnetic member provided with a gap of 10 mm to 10 mm. 2. The non-magnetic member according to claim 1, wherein a tip of said non-magnetic member is displaced from said developer carrying magnetic pole by about 2.5 ° or more upstream or downstream in a developing roller rotation direction. Of an electrophotographic apparatus.