JPH10340029A - Braking mechanism for opc drum - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce jitter caused in an OPC (photoreceptor) drum. SOLUTION: A transfer roller 101 is supported by a bearing 111. The driving gear 102 of the roller 101 is fixed on the roller 101. The driving gear 102 is provided with a flange part. An elastic body 109 such as rubber or felt is brought into contact with the cylindrical inner surface of the flange part so as to generate frictional force. The elastic body 109 is attached and fixed on a supporting member 110. The member 110 to which the elastic body 109 is attached is inserted in the flange part. By forming a projection on an opposite side thereto and hooking the projection on the bearing 111, the elastic body 109 and the member 110 are prevented from being rotated. Since the elastic body 109 is not rotated though the flange part is rotated, the frictional force is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a brake mechanism for an OPC drum, and more particularly to a brake mechanism for an OPC (photosensitive member) drum of an electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, when an OPC drum is contaminated by a rubber component of a developing roller,
The frictional force between the contaminated portion and the transfer roller, the charging brush, and the cleaning blade increases, and jitter may occur due to backlash existing in the rotation drive system of the OPC drum. Since the rotation pitch unevenness corresponding to the backlash occurs on the OPC drum due to the jitter, the image quality such as a character blockage is reduced.

[0003] A conventional brake mechanism for an OPC drum will be described in detail with reference to the drawings.

FIG. 3 is a sectional view showing an example of the prior art. In the brake mechanism of the OPC drum shown in FIG. 3, the drum 11 is rotationally driven by a drive connection mechanism 15 having a backlash.
In the drum unit performed on the case 12 in which the
A brake shoe 13 is provided coaxially with 1 and a biasing means is provided between the drum 11 and the case 12 for biasing them in a direction to separate them to apply a preload between the drum 11 and the case 12. . (See, for example,
No. 065) The brake shoe abuts on the case side by the urging force of the urging means, and a frictional force acts on this abutting surface to brake the rotation of the drum. And the jitter can be reduced. In addition, since the preload is applied between the drum and the case, there is no backlash in the axial direction of the drum, and the pitching is reduced.

[0005]

The above-mentioned conventional OPC
It is difficult to mount the drum brake mechanism on a recent electrophotographic image forming apparatus in which the diameter of the OPC drum is reduced. Also, under the current situation where toner and OPC drums are modularized under the name of “toner cartridge” and disposable electrophotographic image forming apparatuses occupy most of the market, the number of components of this module is increased. There was a disadvantage that the means could not be adopted.

[0006]

According to a first aspect of the present invention, a brake mechanism for an OPC drum includes an OPC drum having a rubber component of a developing roller.
In order to solve a phenomenon such as a character clogging that occurs when the PC drum is contaminated, a friction force generated by applying a friction member to a flange portion of a gear of a transfer roller driven by a gear provided on the OPC drum is used. The developing roller always rotates the OPC drum in a direction in which the OPC drum rotates in a direction larger than the rotating force of the OPC drum, thereby preventing the friction driving force from reversing in the driving direction.

According to a second aspect of the invention, there is provided a brake mechanism for an OPC drum, wherein a transfer roller supported by a bearing, a gear having a flange fixed to the transfer roller, and an elastic body are bonded and inserted into the flange. And a support member.

According to a third aspect of the present invention, in the brake mechanism for an OPC drum according to the second aspect, the elastic body is rubber or felt.

[0009]

Next, the present invention will be described in detail with reference to the drawings.

FIGS. 1A and 1B are a sectional view and an exploded perspective view showing an embodiment of the present invention, and FIG. 2 is a schematic side view showing an example of use of the present invention. The OPC drum brake mechanism of the present invention includes a transfer roller 101 and an OPC drum 104.
Of an electrophotographic image forming apparatus including a developing roller 105, a charging brush 106, and a cleaning plate 107
In the brake mechanism of the C drum, the OPC drum 104
By providing a brake mechanism on the transfer roller 101 mechanically connected to the
The jitter of the OPC drum 104 is suppressed.

The transfer roller 101 is supported by a bearing 111. The drive gear 102 of the transfer roller 101 is fixed to the transfer roller 101. The drive gear 102 is provided with a flange portion 108. An elastic body 109 such as rubber or felt is brought into contact with the inner surface of the cylinder of the flange portion 108 to generate a frictional force. The elastic body 109 is adhered and fixed to the support member 110. The support member 110 to which the elastic body 109 is adhered is inserted into the flange portion 108, and a projection is provided on the opposite side. The projection is hooked on the bearing 111 to prevent the elastic body 109 and the support member 110 from rotating. Since the elastic body 109 does not rotate with respect to the rotating flange portion 108, a frictional force is generated.

The magnitude of the frictional force can be controlled by the coefficient of friction between the elastic body 109 and the flange 108 and the amount of the elastic body 109 crushed.

The transfer roller 101 receives a driving force from a gear 103 of an OPC drum 104 by a driving gear 102, and both are mechanically connected.

[0014]

The brake mechanism of the OPC drum according to the present invention mounts a brake on the transfer roller instead of mounting the brake directly on the OPC drum, so that it can be easily applied to a recent downsized electrophotographic image forming apparatus. And the effect that image quality can be improved.

[Brief description of the drawings]

FIGS. 1A and 1B are a sectional view and an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is a schematic side view showing an example of use of the present invention.

FIG. 3 is a cross-sectional view showing an example of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Transfer roller 102 Gear 103 Gear 104 OPC drum 105 Developing roller 106 Charging brush 107 Cleaning blade 108 Flange part 109 Elastic body 110 Support member 111 Bearing

Claims (3)

[Claims] 1. A flange of a gear of a transfer roller driven by a gear provided on the OPC drum in order to solve a phenomenon such as a character clogging that occurs when the OPC drum is contaminated by a rubber component of a developing roller. OPC characterized in that the frictional force generated by applying a frictional member to the portion is always greater than the force of the developing roller to rotate the OPC drum in the rotation direction of the OPC drum, thereby preventing the frictional driving force from reversing in the driving direction. Drum brake mechanism. 2. A transfer roller supported by a bearing, a gear having a flange fixed to the transfer roller, and a support member to which an elastic body is bonded and inserted into the flange. OPC drum brake mechanism. 3. The brake mechanism for an OPC drum according to claim 2, wherein said elastic body is rubber or felt.