JPS6359147B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor, and particularly to a sheet-shaped electrophotographic photoreceptor that is wound around a drum having a recessed portion formed in a portion of its circumferential surface.

Conventionally, in FIG. 1, such an electrophotographic photoreceptor 1 has a plurality of rectangular stopper holes 2 and 3 formed in a leading edge 1a and a trailing edge 1b, respectively, in the moving direction of the photoreceptor 1 as shown by arrows. ing. These retaining holes 2 and 3 are engaged with retaining pawls on the lagging and advancing sides of the drum rotation direction of the drum concave portion (not shown), and the photoreceptor 1 is held against the drum circumferential surface by unillustrated tensioning means. It is now being wrapped.

As shown in FIG. 2, this photoreceptor 1 is placed on the top surface of the base film 4 that contacts the drum peripheral surface in order.
An aluminum vapor deposition layer 5, a carrier generation layer 6, and a charge transfer layer 7 are laminated. Since only the charge transfer layer 7 is cut off from the leading edge 1a and the trailing edge 1b, the carrier generation layer 6 is exposed at these edges. The carrier generation layer 6 is electrically conductive and has no potential applied thereto, so that toner does not adhere thereto.

FIG. 3 shows the vicinity of the drum recess, and the photoreceptor 1 is wound around the circumferential surface of the drum 8. As shown in FIG. The leading edge 1a and the trailing edge 1b of the photoreceptor 1 are respectively locked by locking claws 9 through locking holes (not shown) and are kept under tension. In this state, the leading edge 1a and trailing edge 1b of the photoreceptor 1 are positioned in the recessed portion of the drum 8, and the charge transfer layer 7 of the photoreceptor 1 is stretched over the cylindrical circumferential surface of the drum 8. It's becoming like that.

Now, a separation claw 10 is disposed near the drum 8 with one end pivotally connected to an immovable pin 11, and when a transfer command is issued, the other end 10a is brought close to the drum circumferential surface. oscillate. The timing of the swinging of the separation claw 10 is such that the drum concave portion is at the separation claw end 1.
0a, the tip 10a lightly rubs against the tip edge 1a of the photoreceptor 1. Stoppa 1
2 limits the swinging angle of the separation claw 10, and the photoreceptor 1
It is considered not to damage the leading edge 1a of the.

When a paper feed command is issued, the transfer paper 13 is fed toward the drum 8, and its leading edge 13a extends beyond the edge of the photosensitive layer 7 by about 2 to 7 mm from the leading edge 1a of the photoreceptor (carrier generation layer 6). It is placed in a position that covers it. As clearly shown in the figure, a space is formed between the leading edge 13a of the transfer paper and the leading edge 1a of the photoreceptor. Easily raised and separated.

Incidentally, for separation, the transfer paper 13 penetrates about 2 to 7 mm into the leading edge 1a of the photoconductor, which is a conductive layer, but since no potential is applied to the conductive layer 1a and toner does not adhere to it, no image is formed. It appears as a white spot.

However, although the separation claw 10 is normally separated from the drum 8, when it is separated, it connects to the photoreceptor 1 in the area indicated by the symbol α, resulting in damage to the conductive layer portion 1a as the number of copies increases. . When the conductive layer portion 1a is scratched, the insulating layer is exposed and toner T adheres to the scratched portion as shown in FIG. This adhered toner T is collected by the separation claw 10 and transferred to the next transfer paper 13A, and appears at the leading edge of the image as a separation claw mark, which has the drawback of deteriorating copy quality.

Therefore, in order to prevent the occurrence of scratches on the conductive layer portion, if the thickness is increased and reinforced, a large force is required to stretch the photoreceptor 1 on the drum circumferential surface, and as shown in FIG. As shown, the photoreceptor 1 is partially lifted from the circumferential surface of the drum 8 (section P in the figure), and the gap between that part and the developing sleeve (not shown) changes, changing the developing characteristics, and as a result, other This has the drawback that differences in density occur between parts and appear in the image as density unevenness, ultimately degrading the copy quality.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional drawbacks and to provide an electrophotographic photoreceptor that can produce images without separation claw marks or density unevenness.

This purpose is a photoreceptor used in a copying machine, and a charge transfer layer on the surface of which a visible image is formed;
a conductive layer formed under the charge transfer layer;
an insulating layer formed under the conductive layer, and the edge portion where the conductive layer is exposed by peeling off the charge transfer layer is fixed to the drum. A photoreceptor in a copying machine, comprising a photoreceptor and a separation claw that contacts the charge transfer layer of the photoreceptor and separates a transfer paper onto which a visible image has been transferred from the charge transfer layer, the photoreceptor having at least an exposed A photoreceptor for electrophotography, characterized in that a conductive layer is fixed to a portion of the conductive layer which is in sliding contact with the separation claw, thereby reinforcing the portion where the separation claw comes into sliding contact. achieved.

According to the present invention, the conductive film is reinforced at the part where the photoreceptor is rubbed by the separating claw, so even if this conductive film is damaged after copying a large number of sheets, the insulating layer will not be exposed. Toner does not transfer and separation marks do not appear on the image. Further, since the photoreceptor is not thick over the entire area, the photoreceptor is brought into close contact with the drum surface, and uneven density does not occur in the image.

The illustrated embodiment will be described in detail below.

FIG. 6 shows the leading edge 1a of the photoreceptor 1, and the thickness is exaggerated. That is, in the figure, the photoreceptor 1 has its leading edge 1a as in the conventional case.
The charge transfer layer 7 is cut to expose the carrier generation layer 6. The carrier generation layer 6 exposed at this tip edge 1a has conductivity, and this portion corresponds to the position where the separating claw slides. Therefore, in the direction perpendicular to the direction of movement of the photoreceptor, the width W is set at the corresponding position of the separation claw.
A thin aluminum film 20 having a diameter of about 10 mm and a thickness t of about 5 to 10 μm is deposited and reinforced. In this case, the number of separation claws is shown as two, but of course the number of separation claws may be any number.
The number of 0s corresponds to the number of separation claws.

Furthermore, the present invention does not limit the conductive layer to be reinforced to an aluminum thin film; for example, it may be formed by applying a conductive paint such as commercially available Fujikura Kasei Type XC32 or XC12. Alternatively, a thin film made of the same material as the carrier generation layer may be attached.

FIG. 7 shows another embodiment of the invention,
In this case, a reinforcing conductive layer 21 longer than the leading edge 1a of the photoreceptor, for example, an aluminum thin film or the same material as the carrier generation layer, is attached. Compared to the embodiments described above, this has the advantage that it also serves to protect the charge transfer layer 7 and prevents the charge transfer layer 7 from being scratched by the tips of the separating claws.

[Brief explanation of the drawing]

1 and 2 are a plan view and a side view showing a conventional photoconductor, FIGS. 3 to 5 are diagrams for explaining the problems of the conventional photoconductor, and FIG. 6 is an embodiment of the present invention. FIG. 7 is a partially enlarged perspective view showing another embodiment of the present invention. 1... Photoreceptor, 2, 3... Stopping hole, 1a... Leading edge, 1b... Trailing edge, 4... Base film,
5... Aluminum vapor deposition layer, 6... Carrier generation layer, 7
... Charge transfer layer, 8 ... Drum, 10 ... Separation nail, 13 ... Transfer paper, 20, 21 ... Conductive layer film.

Claims (1)

[Claims] 1. A drum around which a photoreceptor is wound, a charge transfer layer on which a visible image is formed, a conductive layer formed under the charge transfer layer, and a conductive layer formed under the charge transfer layer. a sheet-like photoreceptor having an insulating layer formed under the layer, and having an edge portion where the conductive layer is exposed by peeling off the charge transfer layer fixed to the drum; A photoreceptor in a copying machine, comprising a separation claw that contacts the charge transfer layer of the photoreceptor and separates a transfer paper onto which a visible image has been transferred from the charge transfer layer, the photoreceptor comprising at least the exposed conductive member. 1. A photoreceptor for electrophotography, characterized in that the layer has a conductive layer, and has a conductive layer fixed to the part where the separating claw slides, thereby reinforcing the part where the separating claw slides.