JPH10340028A - Electronic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an image defect from being caused by supporting by a bearing the end parts of a drum-shaped conductive base of the electronic photosensitive body which has a photosensitive layer laminated and also has the same diameter by bearings, and driving and rotating the end parts. SOLUTION: Thus electronic photoreceptor 15 is supported by a bearing and uses the conductive base having the same diameter so that the support surface 18 of a rotary support shaft 17 which is rotating, the operation surface 20 of a tangential force operation shaft 19 which receives a rotary driving force, and a photosensitive layer surface 21 where an image is formed are in level. In a photosensitve area of the drum-shaped conductive base, an organic photosensitive layer of selenium, amorphous silicon, etc., or a single layer or laminate type organic photosensitive layer is formed. At the end part, nonphotosensitive areas for contacting the bearing 16 and a rotary driving force transmission member is provided. As this drum-shaped conductive base, a metallic pipe is used which is formed of stainless steel of SUS304, aluminum, aluminum alloy, etc.

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 for an electrophotographic copying machine, a printer and the like.

[0002]

2. Description of the Related Art In general, an image forming apparatus such as a copying machine or a printer of an electrophotographic system generally uses a motor to drive a gear or a timing belt to rotate an image forming element such as an electrophotographic photosensitive member at a constant speed. Driving force is transmitted through. For example, when driving force is transmitted via a plurality of gears, vibration is likely to occur due to eccentricity of the gears and a meshing error. In addition, when the driving force is transmitted using the timing belt, uneven rotation of the teeth due to uneven pitch of the teeth and eccentricity of the pulley are likely to occur.

[0003] These vibrations and rotation unevenness cause image density unevenness in a monochrome copying machine or printer, and image defects such as color unevenness or streaks in a color copying machine or printer. In recent years, tandem systems have been used in color copiers and printers to increase the output speed. In this system, the above-described vibration and uneven rotation may cause misregistration of each color.

[0004] If the processing and mounting of the members for transmitting the driving force are performed with high accuracy in order to solve these problems, the cost is inevitably increased. Further, no matter how high the accuracy of the driving force transmission mechanism is, if the rotation axis of the electrophotographic photosensitive member or the photosensitive member itself is eccentric, unevenness in the peripheral speed cannot be avoided.

In order to solve this problem, for example, in Japanese Patent Application Laid-Open No. Hei 7-319254, an endless flat belt is brought into contact with the outer peripheral surface of a plurality of electrophotographic photosensitive members, and the outer peripheral surface of the photosensitive member is contacted with the endless flat belt. A method has been proposed in which a driving force is transmitted by a frictional force during the rotation of the photosensitive member and the driving force is rotated to move the outer peripheral surfaces of the plurality of photosensitive members at the same speed.

According to this method, the problem of misalignment due to a dimensional accuracy error of the diameter of the electrophotographic photosensitive member can be solved. Also, since a means for generating vibration from the drive transmission mechanism is eliminated,
Image quality defects due to vibration can also be suppressed. However, with this method, it is not possible to avoid a color shift and a position shift due to eccentricity caused by the support shaft of the electrophotographic photosensitive member.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has provided an image such as a density unevenness, a color unevenness, a streak, and a position shift due to vibration and eccentricity of a driving force transmission mechanism, and dimensional accuracy error of a photosensitive member. An object of the present invention is to provide an electrophotographic photoreceptor that can prevent the occurrence of image defects due to friction between a photoreceptor, a bearing that supports the photoreceptor, and a driving force transmitting member even after long-term use without causing defects. It is.

[0008]

SUMMARY OF THE INVENTION In view of these problems, the present inventors have supported an end portion of a drum-shaped conductive substrate having the same diameter on which a photosensitive layer of an electrophotographic photosensitive member is laminated by a bearing (photosensitive layer). Is supported by bearings on the surface having the same diameter as the surface on which the is provided), and the end is rotationally driven by a flat belt, a wire, a roller, or the like, thereby suppressing vibration and eccentricity of the driving force transmission mechanism, and We succeeded in eliminating image defects such as density unevenness, color unevenness, and misregistration by reducing the influence of the dimensional accuracy error of the photoconductor.

When an aluminum pipe is used as the substrate, a non-image area (an area having no photosensitive layer) in contact with a bearing or a driving force transmitting member of the substrate is subjected to an anodizing treatment or a hard coating treatment. By forming the layer, a wear-resistant layer is formed, the occurrence of cuts at the contact portion is eliminated, and deformation due to abrasion is prevented, thereby resulting in image defects such as density unevenness, color unevenness, streaks, and misregistration. Succeeded in preventing the occurrence.

That is, the present invention has made it possible to solve the above-mentioned problems by employing the following configuration. (1) In an electrophotographic photosensitive member having a photosensitive layer laminated on a conductive substrate, a drum-shaped substrate having the same diameter as the substrate is used,
A non-photosensitive area is provided at an end of the base, a part of the area is supported by a bearing, and the other part of the area is brought into contact with a rotational driving force transmitting member to rotate the photoconductor. An electrophotographic photosensitive member characterized by the following.

(2) The electrophotographic photosensitive member according to (1), wherein the substrate is a stainless steel pipe. (3) The electrophotographic photosensitive member according to (1), wherein the substrate is an aluminum pipe or an aluminum alloy pipe, and the non-photosensitive region has a wear-resistant layer. (4) The electrophotographic photosensitive member according to (3), wherein the wear-resistant layer is formed by performing an anodic oxidation treatment. (5) The electrophotographic photosensitive member according to (3), wherein the abrasion-resistant layer is formed by performing a hard coat treatment.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The electrophotographic photoreceptor of the present invention has a photosensitive area on a drum-shaped conductive substrate having the same diameter, an inorganic photosensitive layer such as selenium or amorphous silicon, or a single-layer or laminated organic photosensitive layer. Is formed. FIG. 1 is a schematic view of the electrophotographic photosensitive member of the present invention. A photosensitive layer having a width required for image formation is formed at a central portion of the drum-shaped conductive substrate having the same diameter, and a non-photosensitive region for contacting a bearing and a rotational driving force transmitting member is provided at an end portion. Have been.

The drum-shaped conductive substrate used in the present invention includes:
A metal pipe made of stainless steel such as SUS304, aluminum, an aluminum alloy, or the like is used. At one or both ends of the conductive substrate, a non-photosensitive area for supporting the electrophotographic photoreceptor and transmitting driving force is provided. The width is determined by the width of the bearing and the rotational driving force transmitting member, but is preferably in the range of usually 10 to 120 mm.

When the conductive substrate is a stainless steel pipe, the non-photosensitive area may be subjected to the same underlying treatment as that of the photosensitive area, and may be subjected to sand blasting, centerless polishing or the like to improve frictional force, if necessary. May be done.

When the conductive substrate is an aluminum pipe or an aluminum alloy pipe, the non-photosensitive area is subjected to a treatment for improving abrasion resistance. Examples of this treatment include anodic oxidation treatment and hard coat treatment represented by a silicon hard coat agent.

The driving force transmitting member used in the present invention includes:
Examples thereof include metal belts made of stainless steel, phosphor bronze, nickel, and the like, and flat belts in which a core material woven with fibers is coated with a urethane resin or the like. The bearing of the electrophotographic photosensitive member used in the present invention is preferably a stainless steel bearing.

At one or both ends of the conductive substrate of the present invention, a non-photosensitive area for supporting the electrophotographic photosensitive member and transmitting the driving force is provided, and the wear resistance of this area is ensured. In addition, it was possible to substantially prevent wear due to friction with the bearing and the driving force transmitting member, and as a result, it was possible to prevent problems such as image quality deterioration.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to embodiments. [Embodiment 1] FIG. 2 shows a schematic configuration of a tandem type color copying apparatus to which the electrophotographic photosensitive member of the present invention is applied. In FIG. 1, reference numerals 1Y, 1M, 1C, and 1K denote electrophotographic photosensitive members that form toner images of yellow, magenta, cyan, and black, respectively. These are arranged in parallel at a predetermined interval from each other. Each of the electrophotographic photoreceptors is uniformly charged by a charging unit (not shown), and then is exposed to an exposure device such as a semiconductor laser (# 1, # 2, # 3,
An electrostatic latent image is formed by # 4). Next, the electrostatic latent image is developed by yellow, magenta, cyan, and black developing means (2Y, 2M, 2C, 2K) to form toner images of the respective colors. ,
3M, 3C and 3K) are sequentially transferred to a sheet.
The sheet is fed from a sheet feeding device 4, a toner image is transferred while being transported by a transport device 5, and sent to a fixing device 6. The transport device 5 includes a transport belt that moves between a driving roll 7 and another roll 8 and a tension roll 9. The sheet on which the toner image has been transferred passes through the fixing unit 6,
The toner image is fixed on the paper.

FIG. 3 shows a configuration example of a driving force transmission mechanism for rotating and driving the electrophotographic photosensitive member in the above-described image forming apparatus. FIG. 4 is a plan view of FIG. The mechanism includes a drive shaft 11 driven by a single motor (not shown), and a driving force transmitting member 12 wound around the drive shaft.
A tension roll 13 for applying a predetermined tension to the driving force transmission member 12, and a wrap for bringing the driving force transmission member 12 into contact with the peripheral surface of the electrophotographic photosensitive member (1Y, 1M, 1C, 1K) at a predetermined wrap angle. It has an angle setting roll 14.

The driving force of the motor is transmitted to the electrophotographic photosensitive members by the frictional force between the driving force transmitting member 12 and the electrophotographic photosensitive members (1Y, 1M, 1C, 1K), and each of the electrophotographic photosensitive members is driven to rotate. You.

FIG. 5 is a schematic sectional view for explaining the drive transmission mechanism of the electrophotographic photosensitive member of FIG. 2, FIG. 6 is an enlarged plan view of the drive transmission section of FIG. 5, and FIG. 7 is a front view of FIG. FIG. The electrophotographic photoreceptor 15 is supported by bearings 16. At this time, the electrophotographic photoreceptor 15 has a support surface 18 of a rotating rotating support shaft 17, a working surface 20 of a tangential force acting shaft 19 receiving a rotational driving force, In addition, a conductive substrate having the same diameter is used so that the photosensitive layer surface 21 on which an image is formed is on the same plane.

In this embodiment, in the configuration shown in FIG. 3, the conductive base of the electrophotographic photosensitive member (1Y, 1M, 1C, 1K) is formed of a stainless steel pipe made of SUS304 and having a diameter of 30 mm. A rotation driving durability test was performed using a stainless steel belt having a width of 10 mm and a thickness of 80 μm. As a result, even after the test where the number of rotations of the electrophotographic photosensitive member was 100,000, the occurrence of cuts due to wear in the bearing portion and the driving force transmitting portion of the electrophotographic photosensitive member was not visually observed. As for the rotation unevenness, when a print test having the configuration shown in FIG. 2 was performed, no image quality defect due to the rotation unevenness was confirmed.

Example 2 The conductive substrate of the electrophotographic photosensitive member in Example 1 was replaced with an aluminum pipe having a diameter of 30 mm, and a width of 30 mm and a thickness of 10 μm were applied to bearing portions and driving force transmitting portions at both ends thereof. A rotation drive durability test was performed in the same manner as in Example 1 except that the anodic oxidation treatment was performed. As a result, even after the test of 100,000 rotations of the electrophotographic photosensitive member, occurrence of cuts due to wear in the bearing portion and the driving force transmitting portion of the electrophotographic photosensitive member and uneven rotation due to the wear were observed. Did not.

Example 3 The conductive substrate of the electrophotographic photosensitive member in Example 1 was replaced with an aluminum pipe having a diameter of 30 mm. And a silicon hard coat treatment having a thickness of about 10 μm was performed. Hard coat agent: 50 parts by weight, Glasca G1100 manufactured by Nippon Synthetic Rubber Co., Ltd. Solvent: 30 parts by weight of isopropyl alcohol Coating method: dip coating Drying condition: 150 ° C., 10 minutes

A rotation driving durability test was performed in the same manner as in Example 1 except that the driving force transmitting member in Example 1 was replaced with a flat belt in which the periphery of a core material knitted with Kevlar fiber was coated with urethane resin. went. As a result, even after the test of 1,000,000 rotations of the electrophotographic photosensitive member, occurrence of cuts due to wear in the bearing portion and the driving force transmitting portion of the electrophotographic photosensitive member and uneven rotation due to the wear were observed. Did not.

[Comparative Example 1] A rotary drive durability test was performed in the same manner as in Example 3 except that the bearing portions and the driving force transmitting portions at both ends of the aluminum pipe were not subjected to any special treatment. As a result, at the time when the number of rotations of the electrophotographic photosensitive member was 3000, the rotation unevenness due to the occurrence of cuts was remarkably observed.

[0027]

According to the present invention, by adopting the above-mentioned structure, even if the bearing is applied to the electrophotographic photosensitive member or the frictional force is applied by the driving force transmitting member, the problem of deterioration in image quality caused by abrasion does not occur. Photoconductors can now be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view of an electrophotographic photosensitive member according to the present invention.

FIG. 2 is a schematic configuration diagram of a tandem-type color copying apparatus to which the electrophotographic photosensitive member of the present invention is applied.

FIG. 3 is a diagram illustrating a configuration example of a rotation drive transmission mechanism of the image forming apparatus of FIG. 2;

FIG. 4 is a plan view as viewed in the direction of the arrow in FIG. 3;

FIG. 5 is a schematic configuration diagram for explaining the drive transmission mechanism of FIG. 3;

FIG. 6 is an enlarged plan view of the drive transmission unit of FIG.

FIG. 7 is a front view of the drive transmission unit of FIG. 6;

Claims (3)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer laminated on a conductive substrate, wherein a drum-shaped substrate having the same diameter is used as the substrate, and a non-photosensitive region is provided at an end of the substrate. The electrophotographic photoreceptor is characterized in that the photoreceptor is rotated by supporting a portion of the photoreceptor with a bearing and bringing the other part of the region into contact with a rotational driving force transmitting member. 2. The electrophotographic photosensitive member according to claim 1, wherein said substrate is a stainless steel pipe. 3. The electrophotographic photoreceptor according to claim 1, wherein said substrate is an aluminum pipe or an aluminum alloy pipe, and said non-photosensitive area has a wear-resistant layer.