JPH08248826A - Electrophotographic photoreceptor and electrophotographic device incorporated therewith - Google Patents

Abstract

PURPOSE: To provide an electrophotographic photoreceptor capable of keeping stable contact pressure with a roller member arranged in an adjacent relation, without causing the problems of the wearing and peeling of a roller contact part and an electrophotographic device incorporated with the photoreceptor. CONSTITUTION: The end face of the photoreceptor 1 is constituted of a flange 12, it is provided with an outer cylindrical part 12a a little extended to the side of the photoreceptor 1 and its end part is covered with the outer cylindrical part 12a. A roller 15 coming into contact with the photoreceptor 1, for instance, an electrifying roller is adjusted in the contact pressure with the photoreceptor 1 by a roller 16 coming into press-contact with the outer cylindrical part 12a. It can be provided with a collar on the inside edge in the axial direction of the outer cylindrical part, 12a, to prevent the roller 16 from coming out of the outer cylindrical part 12a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member used in an electrophotographic apparatus such as a copying machine and an electrophotographic apparatus equipped with the same.

[0002]

2. Description of the Related Art An electrophotographic apparatus is a photoconductor (photosensitive drum).
An electrostatic latent image is formed on an electrostatic latent image, the latent image is developed with charged colored particles (generally called toner), and the obtained image is transferred to a transfer paper. Widely used in copiers, facsimiles, printers, etc.

FIG. 4 shows a general structure of a photoreceptor used in this type of apparatus. In the figure, reference numeral 30 is a photosensitive member, and the photosensitive member 30 has a cylindrical support 31 and a photosensitive layer 32 forming a surface layer thereof, and is formed by a flange 33. Since such a photosensitive member forms an image by contacting with various rollers contacting the photosensitive member, such as a charging roller and a transfer roller, mechanical strength of the outer surface of the photosensitive member is required. JP-A-60-194459
The publication discloses a proposal to improve the mechanical strength of the photoconductor by forming the outer surface of the photoconductor with an insulating layer.

By the way, in order to properly adjust the contact pressure between the photosensitive member and the roller, a roller provided on the roller side is generally used, and the roller is pressed against the end of the photosensitive member. Has been adopted (see JP-A-61-100755). Therefore, not only the problem of wear but also a relatively large pressure is applied to the contact portion of the roller on the photoconductor, so that the photoconductor is apt to be distorted due to stress and cause problems such as peeling of the outer surface layer. It has become a thing. Of course, when peeling occurs at the roller contact portion of the photoconductor, the contact pressure between the photoconductor and the roller fluctuates, which causes an abnormal image. In order to deal with such a problem, the above-mentioned Japanese Patent Laid-Open Publication No. 61-100755 proposes to form the roller contact portion of the photoconductor with an elastic material that is strong against stress strain.

[0005]

However, when the roller contact portion of the photoconductor is made of an elastic material, it becomes difficult to make the contact pressure between the photoconductor and the roller constant due to the elasticity. Therefore, an object of the present invention is to mount an electrophotographic photosensitive member capable of maintaining a stable contact pressure between adjacent roller members without causing the problems of abrasion and separation of the roller contact portion. To provide the electrophotographic apparatus.

[0006]

In order to achieve the above technical object, the electrophotographic photosensitive member of the present invention is provided with a cylindrical support and an outer peripheral surface of the cylindrical support. Assuming an electrophotographic photosensitive member having a photosensitive layer and a flange forming an end surface of the cylindrical support, the flange is provided with an outer cylinder portion slightly extending inward of the photosensitive member. A configuration is adopted in which the end portion of the photoconductor is covered by the tubular portion.

In the electrophotographic apparatus of the present invention,
Roller members arranged in parallel so as to come into contact with a photoconductor having a cylindrical support, a photosensitive layer provided on an outer peripheral surface of the cylindrical support, and a flange forming an end face of the cylindrical support. On the premise of an electrophotographic apparatus having the above, the flange is provided with an outer cylinder portion that slightly extends inward of the photosensitive member and covers an end portion of the photosensitive member, and the roller member has rollers at both ends thereof. The rollers are rotated by the rotation of the photoconductor while adjusting the contact pressure between the roller member and the photoconductor by pressing these rollers against the outer cylinder. The structure is adopted.

According to the electrophotographic photosensitive member and the electrophotographic apparatus according to the present invention as described above, since the roller does not directly contact the outer surface of the photosensitive member, there is a problem such as peeling of the outer surface of the photosensitive member. It never happens. Therefore, it becomes possible to solve the conventional problem that the roller directly presses against the photosensitive member. Further, since the roller is brought into contact with the outer cylinder portion provided on the flange, it is possible to stably maintain the contact state between the photoconductor and the roller member.

The outer cylinder portion may be provided with a flange portion that extends slightly outward in the radial direction at the inner end on the photoreceptor side, and the flange portion may allow play in the axial direction of the roller. Even if the roller moves to some extent in the axial direction, the roller is received by the flange portion and is prevented from being separated from the outer cylinder portion.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 3 shows a part of the electrophotographic apparatus. In FIG. 1, reference numeral 1 is a photoconductor, that is, a photoconductor drum. The photoconductor 1 rotates in the direction of arrow A in the figure, is first charged by the charging unit 2, and is exposed by the exposure unit 3 to form an electrostatic latent image. Is formed. After that, the developing means 4 develops the exposed portion with the toner in the reverse developing method (N / P method) and the unexposed portion in the positive developing method (P / P method), and then, Transfer means 5
Is transferred to the transfer paper. After transferring this toner image, the photoconductor 1 is subjected to cleaning by the cleaning unit 6 and static elimination by the static elimination unit 7. In FIG. 3, the charging means 2 and the transfer means 5 are drawn in a roller shape, but these means may use a corotron or a scorotron charger, or a belt shape. May be

FIG. 1 shows a photoreceptor 1 according to an embodiment of the present invention. The photoreceptor 1 has a cylindrical conductive support 8 and a photosensitive layer 10 provided on the outer peripheral surface of the support 8. The photosensitive layer 10 may be any material known in this technical field, for example, an inorganic photosensitive material or an organic photosensitive material, and may be a single layer type or a laminated type composed of a charge generation layer and a charge transport layer. Either may be used.

Both ends of the photosensitive member 1 are composed of flanges 12, and the flanges 12 are attached by being pressed into the supporting member 8. The flange 12 has an outer cylindrical portion 12a having an inner diameter substantially the same as the outer diameter of the photoconductor 1. The outer cylinder portion 12a extends slightly inward of the photoconductor 1,
The outer peripheral surface has a smooth surface shape. Outer tube part 1
A gap of, for example, about 0.1 mm or less, preferably 0.03 mm or less is provided between the inner peripheral surface of 2a and the photosensitive member 1, and the flange 1
It is preferable to prevent the photosensitive layer 10 from being scratched by the outer cylindrical portion 12a when the 2 is pressed into the support 8.

A drum shaft 13 is provided on the flange 12, and the drum shaft 13 is rotationally driven by driving means (not shown) via the drum shaft 13. As a modified example, a gear may be provided on the outer peripheral surface of the flange 12, and the rotational force from the drive means may be obtained via this gear. An outer peripheral surface of a roller 15 disposed adjacent to the photosensitive layer 10 of the photosensitive member 1 is in contact with the photosensitive layer 10, and a roller 16 disposed coaxially with the roller 15 is pressed against the outer cylindrical portion 12a. The roller 15 rotates following the rotation of the photoconductor 1. The roller 15 may be any of the rollers constituting the charging unit 2, the transfer unit 5, the developing unit 4, and the cleaning unit 6 described above, or all of them.

When the shaft 17 of the roller 15 is pressed toward the photoconductor 1 by a means (not shown), the roller 16 moves to the outer cylinder portion 12.
It is pressed against a with a predetermined force. The radius of the roller 15 is preferably set to be slightly larger than the sum of the radius of the roller 16 and the wall thickness of the outer cylindrical portion 12a, for example, about 0.1 to 5 mm. Further, it is preferable that the roller material 15a forming the outer peripheral portion of the roller 15 has an appropriate hardness such that the roller material 15a is sufficiently elastically deformed by the contact force applied to the roller shaft 17. As a result, the roller outer surface material 15a can uniformly contact the photosensitive layer 10 in the axial direction.

FIG. 2 shows a modification of the flange 12 shown in FIG. In the flange 20 shown in FIG. 2, a flange portion 12b that extends slightly outward in the radial direction is provided at the end of the outer cylindrical portion 12a on the side of the photoreceptor 1. This collar 12b
Thus, even if the roller 16 has some play in the axial direction, the roller 16 is received by the flange portion 12b, and the roller 16 comes off the outer cylinder portion 12a and comes into direct contact with the photosensitive layer 10. This can prevent the photosensitive layer 10 from being damaged. Next, some results of concrete implementation will be described as experimental examples.

Experimental Example 1 On an aluminum support 8 having an outer diameter of 30 mm and a length of 306 mm, an undercoat layer containing an alkyd resin having a thickness of about 3 μm and an inorganic pigment as main components, and an azo pigment having a thickness of about 0.1 mm are successively formed. A photoconductor 1 was prepared by forming a photosensitive layer 10 composed of a charge generation layer containing as a main component and a charge transport layer having a thickness of about 25 μm by a dip coating method.
After attaching the flanges 12 shown in FIG. 1 to both ends of the photoconductor 1, image evaluation was performed by using a remodeling machine of RIFAX 110L manufactured by Ricoh Co., which has a charging roller having a roller 16 at the ends and a transfer roller. A good image was obtained.

Experimental Example 2 The same photoconductor 1 as in Experimental Example 1 was prepared, and the flanges 20 shown in FIG. 2 were attached to both ends of the photoconductor 1, and then a charging roller having a roller 16 and a transfer roller made by Ricoh Co. RIFAX 11
Image evaluation was performed using a 0L modified machine. In addition, roller 16
Had an axial play of about 3 mm. As a result of this experiment, the roller 16 does not come off from the outer cylinder portion 12a,
Good images were obtained up to 000 sheets.

Comparative Example 1 The same photosensitive member 1 as in Experimental Example 1 was prepared, the flanges 30 shown in FIG. 4 were attached to both ends of the photosensitive member 1, and image evaluation was performed in the same manner as in Experimental Example 1. As a result, from about 13,000 sheets, the edge of the photosensitive layer started to wear due to rollers, and about 17,0
At 00 sheets, the photosensitive layer was peeled off and an abnormal image was generated, so the subsequent evaluation was stopped.

[0019]

As is apparent from the above description, according to the present invention, there is no problem of wear and peeling of the roller abutting portion of the photoconductor, and the gap between the roller member and the roller member arranged adjacently is eliminated. A stable contact pressure can be maintained. Also, in the case where a flange is provided on the outer cylinder of the flange, the play in the axial direction of the roller is allowed, and the roller comes off the outer cylinder and comes into contact with the outer surface of the photoconductor. Can be prevented.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a photosensitive member and an adjacent roller member according to an exemplary embodiment of the present invention.

FIG. 2 is a sectional view of a flange shown as a modified example.

FIG. 3 is a schematic diagram showing a configuration of a main part of an electrophotographic apparatus.

FIG. 4 is a partial cross-sectional view showing an example of a conventional photoconductor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging means 4 Developing means 5 Transfer means 6 Cleaning means 8 Cylindrical support 10 Photosensitive layer 12, 20 Flange 12a Outer cylinder part 12b Collar part 15 Roller 16 Roller

Claims (4)

[Claims] 1. An electrophotographic photoreceptor having a cylindrical support, a photosensitive layer provided on an outer peripheral surface of the cylindrical support, and a flange constituting an end surface of the cylindrical support, wherein the flange The electrophotographic photosensitive member is characterized in that an outer cylinder portion slightly extending inward of the photosensitive member is provided, and an end portion of the photosensitive member is covered with the outer cylinder portion. 2. A cylindrical support, a photosensitive layer provided on an outer peripheral surface of the cylindrical support, and a flange forming an end surface of the cylindrical support are parallel to each other so as to be in contact with the photosensitive body. In the electrophotographic apparatus having arranged roller members, the flange is provided with an outer cylinder portion that slightly extends inward of the photosensitive member and covers an end portion of the photosensitive member, and the roller member has both ends thereof. Have rollers, and by adjusting the contact pressure between the roller member and the photoconductor by pressing these rollers against the outer cylinder portion, the roller member is driven by the rotation of the photoconductor. An electrophotographic device characterized in that the rotating body. 3. The electrophotographic apparatus according to claim 2, wherein the outer cylinder portion has a flange portion that extends slightly outward in the radial direction at the inner end on the photoreceptor side. 4. The electrophotographic apparatus according to claim 2, wherein the roller member is at least one of a charging roller, a transfer roller, a developing roller, and a cleaning roller.