JP2002296973A - Photoreceptor belt unit for electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoreceptor belt unit being made possible to adjust a gap with regard to the unit oppositely facing the photoreceptor belt, without detaching the photoreceptor belt unit, nor carrying a tool for adjusting from the outside to the inside. SOLUTION: As for this device, the gap adjusting shaft 18 being furnished with an eccentric cam 17 is provided in the vicinity of a transporting roll provided inside the photoreceptor belt unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photoreceptor belt unit for an electrophotographic apparatus.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. 5, 6 and 7. FIG. Conveyance rolls 2, 3, 4, 5, and 6 are provided inside the photoreceptor belt 1, and the photoreceptor belt 1 on which the photoreceptor belt 1 is conveyed by rotation of these rolls and the conveyance rolls 2, Reference numerals 3, 4, 5, and 6 form one photoreceptor belt unit by a frame (not shown). The surface of the photoreceptor belt 1 is uniformly charged by the charger 7, and an electrostatic latent image is formed on the photoreceptor belt 1 by light 8 such as a laser or an LED. The latent image is developed by a developing roll 10 of a developing machine 9, and an image is transferred onto a sheet 12 by a transfer unit 11. The surface of the photoreceptor belt 1 after the transfer is cleaned by a cleaner brush 13.

In the above configuration, the gap between the photoreceptor belt 1 and the charger 7, the photoreceptor belt 1 and the developing roll 1
The gap with 0 must be kept constant at a predetermined value. If the gap is larger than the predetermined value, the charging unit 7 cannot uniformly charge the surface of the photoreceptor belt 1, resulting in uneven charging or an insufficient charging amount. Further, in the developing unit 9, the developer on the developing roll 10 is difficult to uniformly contact the surface of the photoreceptor belt 1, resulting in poor development, resulting in a problem that print density is reduced.

Conversely, if the gap is smaller than the predetermined value, abnormal discharge to the photosensitive belt 1 occurs in the charger 7 and the photosensitive belt is damaged. Further, in the developing unit 9, the developer on the developing roll contacts the photoreceptor belt 1 too much, and the frictional load on the photoreceptor belt increases, so that the photoreceptor belt cannot be transported or the surface of the photoreceptor belt 1 is worn. The problem of being premature occurs. In order to solve these problems, a method is known in which a gap adjusting jig 14 is mounted instead of the photoreceptor belt and the gap is adjusted by a built-in dial gauge 15 as shown in FIG.

As another means for adjusting the gap, for example, as shown in FIG.
There is also known a method in which a gap gauge 16 is inserted between members facing each other and adjusted to a predetermined value.

[0006]

When the gap adjusting jig 14 as shown in FIG. 6 is used, it is necessary to remove the photoreceptor belt unit from the apparatus every time the adjusting operation is performed.
At this time, since the surface of the photoreceptor belt 1 of the photoreceptor belt unit removed is easily deteriorated by natural light or illumination, a light shielding member is required. Must be attached.

In the method of adjusting the gap using the gap gauge 16 as shown in FIG. 7, at least two gap gauges are required at both ends in the longitudinal direction of the transport roll at the portion to be adjusted. When the gap gauge 16 is inserted into the surface of the photoreceptor belt 1, it is necessary to remove the photoreceptor belt 1 from the photoreceptor belt unit every time an adjustment operation is performed so that the surface of the photoreceptor belt 1 is not damaged by the gap gauge. there is.
Further, a predetermined photoreceptor belt 1 of each unit
It is necessary to arrange various thickness gauges corresponding to the predetermined gap with
There were problems such as easy loss.

SUMMARY OF THE INVENTION An object of the present invention is to provide a photoreceptor belt unit having a simple structure and capable of adjusting a gap between opposing units without removing a photoreceptor belt and a photoreceptor belt unit.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photoreceptor belt unit in which a photoreceptor is formed in a belt shape and includes at least two or more belt conveying rollers. This is achieved by providing an adjustment shaft having an eccentric cam member for adjustment in parallel near the belt conveying roller.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1, 2, 3 and 4. FIG. In the present invention, as shown in FIG. 1, two eccentric cams 17 are attached to the gap adjusting shaft 18 at positions outside the width of the photoreceptor belt 1 at both ends in the longitudinal direction of the transport roll. The gap adjusting shaft 18 is attached to a frame 22 of the photoreceptor belt unit by a screw 20 via a shaft holding member 19. The hole of the frame 22 with which the shaft holding member 19 fits is an elongated hole, and the shaft holding member 19 can move in the gap adjustment direction. A groove 23 is provided at an end of the gap adjusting shaft 18 and has a predetermined positional relationship with the phase of the eccentric cam 17.

At the time of gap adjustment, the eccentric cam projects by turning the gap adjustment shaft 18 as shown in FIG. At this time, the gap adjusting shaft 18 is fixed by turning the shaft fixing screw 21. The position of the tip of the protruding eccentric cam 17 is set to be equal to the gap with the photoreceptor belt to be adjusted, and the gap is adjusted by abutting a part of the unit on the eccentric cam 17.

When the adjustment is completed, the shaft fixing screw 21 is loosened and the gap adjusting shaft 18 is turned to retract the eccentric cam 17, and the gap adjusting shaft 18 is fixed again by the shaft fixing screw 21. At this time, since the eccentric cam 17 is located inside the surface of the photosensitive belt 1 as shown in FIG. 4, it does not affect the printing operation.

With the above arrangement, the gap can be adjusted without removing the photosensitive belt unit when adjusting the gap. Further, since the gap adjusting jig is built in the photoreceptor belt unit, the jig is not searched or lost.

When the value of the gap is changed, the screw 20 for fixing the shaft holding member 19 is loosened, and the gap is moved to a desired position along the elongated hole that the shaft holding member 19 opened in the photosensitive belt unit fits. It is possible to respond.

[0015]

As described above, according to the present invention, it is possible to provide a photoreceptor belt unit having a simple structure and capable of adjusting the gap between opposing units without removing the photoreceptor belt unit. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating one embodiment of a photoconductor belt unit according to the present invention when a gap is adjusted.

FIG. 2 is a front view of a shaft holding member.

FIG. 3 is a partial cross-sectional view of the electrophotographic apparatus during gap adjustment.

FIG. 4 is a partial cross-sectional view of the electrophotographic apparatus when the eccentric cam of FIG. 3 is retracted.

FIG. 5 is a cross-sectional view showing one embodiment of a conventional electrophotographic apparatus.

FIG. 6 is a sectional view showing one embodiment of a conventional gap adjusting method.

FIG. 7 is a cross-sectional view showing another example of the conventional gap adjusting method.

[Explanation of symbols]

1 is a photoreceptor belt, 2, 3, 4, 5, and 6 are transport rolls,
7 is a charger, 8 is light, 9 is a developing machine, 10 is a developing roll,
11 is a transfer unit, 12 is paper, 13 is a cleaning brush, 14 is a gap adjusting tool, 15 is a dial gauge,
16 feeler gauge, the eccentric cam 17, 18 gap adjusting shaft 19 is a shaft holding member 20 is threaded, 2
1 shaft fixing screws, 22 is a frame, 23 is a groove.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Isao Nakajima 1060 Takeda, Hitachinaka-shi, Ibaraki F-term in Hitachi Koki Co., Ltd. (Reference) 2H035 CA05 CB06 CD11 CD13 2H071 BA16 BA36 DA16 EA06

Claims (3)

[Claims] An eccentric cam member for adjusting a gap between a photosensitive member and a member opposed to the photosensitive member belt unit is provided. A photoreceptor belt unit for an electrophotographic apparatus, wherein an adjustment shaft having the same is provided in parallel near the belt transport roller. 2. The apparatus according to claim 1, wherein the adjusting shaft has a structure rotatable about an axis, and the eccentric cam member provided on the shaft is positioned at a predetermined position.
A photoreceptor belt unit for the electrophotographic apparatus according to the above. 3. The adjusting shaft is held by a shaft holding member provided on the photoreceptor belt unit, and has a structure in which a gap between the adjusting shaft and an opposing member can be arbitrarily set by moving the fixing position. The photoreceptor belt unit for an electrophotographic apparatus according to claim 1.