JPH0422985A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To mount a conductive cylindrical base body to a shaft for driving without using flanges and to lessen run-out by providing grooves or furrow-like projecting parts from ends toward the inside near at both ends of the inside surface of the cylindrical base body and forming tapers on the inside surfaces thereof. CONSTITUTION:The groove 2 is provided on the inside surface of the cylindrical base body of the photosensitive body 1 and the tapered parts 3 of the taper angle alpha having a vertex on the axis of the cylinder and complying with the outside surface of the imaginary circular cone are formed at both ends thereof from the ends toward the inside. The photosensitive body 1 can, therefore, be mounted to the shaft 4 for rotational driving in such a manner that the tapered parts 3 at the ends fit to the tapered parts 6 of the shaft 4 for rotational driving and that the groove 2 of the inside surface of the base body of the photosensitive body fits to the projecting part 7 of the shaft 4 for rotational driving. The photosensitive body 1 is mounted in such a manner that the photosensitive body can be rotationally driven and the run-out is decreased without previously fixing the flanges.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrophotographic photoreceptor comprising a conductive cylindrical substrate and a photosensitive layer on the outer circumferential surface thereof, and specifically relates to the inner surface shape of the cylindrical substrate.

[Conventional technology]

Electrophotographic photoreceptors are usually made by depositing a photosensitive material on the outer circumferential surface of a conductive cylindrical substrate.Inorganic materials such as selenium alloys are deposited using a vacuum evaporation method, and organic materials are deposited using a coating method. It is manufactured by forming.

In an electrophotographic apparatus such as a copying machine, images are repeatedly formed by an image forming process mechanism disposed along the outer peripheral surface of the photoreceptor while rotating the photoreceptor around the cylindrical axis of the cylindrical base.

Conventionally, such rotation of the photoreceptor is performed by a rotational drive mechanism of the electrophotographic apparatus via flanges attached to both ends of the cylindrical base of the photoreceptor. That is, it has a flange attached by integral molding or assembly with a gear that meshes with a rotational drive gear installed in the device, or a center hole such as a D-shape or H-shape that fits into a rotational drive shaft installed in the device. Fit the flange to both ends of the cylindrical base of the photoconductor by tight fit or clearance fit, and fix with screws as necessary, so that the gear of this flange engages with the gear of the device or the center hole The photoreceptor is mounted in the apparatus so that the photoreceptor is fitted into the rotational drive shaft of the apparatus, and the photoreceptor is rotationally driven in accordance with the image forming process by the rotational drive mechanism of the apparatus.

Such flanges are mainly formed by aluminum die-casting, processed metal such as SUS material, or made of AB
Manufactured by resin molding such as S, POM, etc.

[Problem to be solved by the invention]

As mentioned above, the photoreceptor is rotationally driven via the flange in an electrophotographic device, so if the axis of the cylindrical base of the photoreceptor and the axis of the flange are misaligned, rotational runout of the photoreceptor will occur, which will interfere with image formation. Variations occur in the process, making it impossible to stably obtain images of uniform quality. Therefore, it is necessary to manufacture the flange with high dimensional accuracy, which is expensive, and it is important to fix the flange to the photoreceptor so that there is no misalignment of the axis, which requires a large number of man-hours for installation.

Furthermore, two flanges are generally attached, one at each end of the photoconductor, and are secured by a tight fit, so they are discarded together with the photoconductor when its useful life is over. Ru. Flanges account for a large proportion of the price of photoconductors with flanges attached, including direct materials and man-hours, and the use of photoconductors even though they still have the function of use. There was a problem in that there was a large cost loss because they were disposed of together at the end of their lifespan.

This invention was made in view of the above points, and
An object of the present invention is to provide an electrophotographic photoreceptor that can be rotationally driven without using a flange and has less rotational runout.

[Failure to solve the problem]

According to the present invention, the above-mentioned problem can be solved by wiping an electrophotographic photoreceptor comprising a photosensitive layer on the outer peripheral surface of a conductive cylindrical base, from the end to at least near both ends of the inner surface of the conductive cylindrical base. A groove or ridge-like protrusion is provided inward, and a taper is formed inward from the end along the outer surface of an imaginary cone having an apex on the cylindrical axis. This problem can be solved by using an electrophotographic photoreceptor that uses

[Effect]

A convex portion or a concave portion that engages with the groove or ridge-like protrusion according to the present invention formed on the inner surface of the cylindrical base of the photoreceptor is provided on the rotational drive shaft in the electrophotographic apparatus, and The photoreceptor of the present invention can be manufactured by forming a reverse taper corresponding to the taper formed at the end of the base at the portion where the convex or concave portion of the shaft is provided and comes into contact with the end of the base of the photoreceptor. The tapered portion of the end portion and the tapered portion of the rotational drive shaft fit together, and the groove or ridge-like protrusion on the inner surface of the photoreceptor base and the convex or concave portion of the rotational drive shaft fit together. By attaching the photoconductor to the rotational drive shaft so as to mesh with each other, the photoconductor can be rotationally driven within the electrophotographic device without having to securely attach the flange to the photoconductor in advance by tightly fitting, as in the case of conventional methods. It becomes possible to mount it so that there is little rotational runout.

Further, when the photoreceptor reaches the end of its useful life, the photoreceptor can be easily removed from the electrophotographic apparatus, and only the photoreceptor can be disposed of.

〔Example〕

FIG. 1 is a conceptual diagram showing an embodiment of the photoreceptor of the present invention, and FIG. 1(a) is a front view of the photoreceptor viewed from the cylindrical axis direction;
FIG. 1(b) shows a cross-sectional view taken along the line A-A in FIG. 1(a), and shows that a groove 2 is provided on the inner surface of the cylindrical base of the photoreceptor 1, and a groove 2 is provided at both ends thereof with a taper angle α. Part 3 is formed.

A seamless cold-drawn pipe made of aluminum alloy A3003 is used as the cylindrical base, and the grooves are formed with a drawing die. A photoreceptor was prepared by forming a photosensitive layer on a cylindrical substrate in which a groove with a depth of 2n++++ was formed in a cylinder with a wall thickness of 3 mm, and a part of the taper with a taper angle of 60° was formed at the end.

Such a photoreceptor is used as a second photoreceptor installed in an electrophotographic device.
A flange as shown in FIG. 3 is attached to the rotary drive shaft as shown in the figure.

FIG. 2 is a conceptual side view of an example of a rotational drive shaft, in which a pot 5 that fits with one end of the photoreceptor is formed on the side of the rotational drive shaft 4 that is connected to an external drive motor. The surface in contact with the inner surface of the end of the photoreceptor base has a taper angle of 60°±?, corresponding to a part of the taper at the end of the photoreceptor base. A tapered portion 6 of 5' is formed, and a convex portion 7 that engages with a groove on the inner surface of the photoreceptor base is formed.

In FIG. 3, the photoreceptor is inserted into the rotary drive shaft 4 shown in FIG. This is a conceptual side view of an example of a flange for fixing to a rotational drive shaft.The flange 8 is formed with a center hole 9 that fits into the rotational drive shaft 4, and the outer peripheral surface has a taper at the end of the photoreceptor base. A tapered portion 10 with a corresponding taper angle of 60°±75′ and a convex portion 11 that engages with a groove on the inner surface of the photoreceptor base are formed.

FIG. 4 is a conceptual side view, partially cut away, showing the state in which the photoreceptor 1 is attached to the rotary drive shaft 4 shown in FIG. 2, and is rotatably fixed to the frame 15a of the electrophotographic apparatus. One end of the photoreceptor 1 is fitted to the collar 5 of the rotary drive shaft 4, the flange 8 is fitted to the other end, and the photoreceptor 1 is fixed using a stopper 12 so as not to shift in the axial direction. bottle 1
4 through the frame 15b into the bearing 13 that is press-fitted into the tip of the rotational drive shaft 4.
The tip of the rotary drive shaft 4 is rotatably fixed to the shaft 5b.

By installing the photoreceptor in the electrophotographic apparatus in this manner, the photoreceptor is smoothly rotated by the apparatus's driving motor via the rotational drive shaft. It was confirmed that the rotational runout of the photoreceptor was small and the runout of the outer diameter was suppressed to 0.1 mm or less.

When the photoreceptor reaches the end of its useful life, all you have to do is remove it and dispose of the photoreceptor alone (as the flange can be used repeatedly, there is no cost loss like in the past.

It is desirable to form a large number of grooves on the inner surface of the photoreceptor substrate because the larger the number of grooves, the smaller the load applied to one groove during rotational driving.

In addition, in the embodiment, a groove is formed on the inner surface of the photoreceptor base.

That is, although the concave portion is formed on the rotary drive shaft and the convex portion on the flange side, this combination naturally functions and is effective even if the combination is reversed.

〔Effect of the invention〕

According to the present invention, grooves or ridge-like protrusions are provided at least in the vicinity of both ends of the inner surface of the conductive cylindrical base of the electrophotographic photoreceptor, and the inner surface is provided with grooves or ridge-like protrusions extending inward from the ends. A taper is formed along the outer surface of an imaginary cone that has an apex on the cylindrical axis.

By forming the inner surface of the cylindrical photoreceptor base in this way, it is possible to rotate the photoreceptor inside an electrophotographic device without having to attach flanges to both ends of the photoreceptor by tightly fitting them in advance, as is the case with conventional methods. Therefore, the price of the flange and the cost of attaching the photoreceptor to the apparatus are reduced by the number of man-hours required for attaching the photoreceptor to the apparatus. Further, since the photoreceptor is directly attached to the rotational drive shaft without using a flange, rotational vibration of the photoreceptor is eliminated. Furthermore, when the photoreceptor reaches the end of its useful life, only the photoreceptor can be discarded, which significantly reduces cost losses compared to when the photoreceptor is disposed of with a conventional flange.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing one embodiment of the photoreceptor of the present invention, and FIG.
Figure (b) is a sectional view taken along line A-A in Figure 1 (a), and Figure 2 is a cross-sectional view of Figure 1.
Fig. 3 is a conceptual side view of an example of a rotational drive shaft to which a photoreceptor is attached as shown in the figure, and Fig. 3 is a conceptual side view of an example of a flange used in combination when attaching a photoreceptor to the rotational drive shaft shown in Fig. 2. A side view, FIG. 4 is a conceptual side view showing a partially broken cross section showing a state in which a photoreceptor is attached to the rotary drive shaft shown in FIG. 2. 1 photoconductor, 2 groove, 3 part of taper.

Claims (1)

[Claims] 1) In an electrophotographic photoreceptor comprising a photosensitive layer on the outer circumferential surface of a conductive cylindrical base, grooves or ridge-like protrusions are provided at least near both ends of the inner surface of the conductive cylindrical base from the ends toward the inside. A photoreceptor for electrophotography, characterized in that the inner surface thereof is tapered inward from the end along the outer surface of an imaginary cone having an apex on the cylindrical axis. .