JPH04127187A - Deterioration recovery device for photosensitive body - Google Patents

Abstract

PURPOSE:To recover a deteriorated photosensitive body like a normal one by controlling a circumference or the inside to specific temp. in such a manner that a photosensitive drum is placed in a box shielding light and a heater is attached around the photosensitive body, or a drum shaft having the attachment of the heater is inserted into the photosensitive drum. CONSTITUTION:The heater 2 is provided between a corona electrifier 3 and an exposing unit 4, and between it and a developing unit 5, or the heater 2 is incorporated in the drum shaft 20, and a thermostat 9 controlling a temp. to 40 deg.C - 70 deg.C is provided between an erasing lamp 8 and the corona electrifier 3. When the photosensitive drum 1 is deteriorated, the developing unit 5 is removed, then, the photosensitive drum 1 is heated to 40 deg.C - 70 deg.C, and left for a prescribed time or above. When the face of the photosensitive body 1 is warmed to 40 deg.C - 70 deg.C by the heater 2, the photosensitive body 1 receives heat energy, and an oxide stuck to its surface is removed. Thus, the printing quality of the photosensitive body 1 is improved, and the deteriorated photosensi tive body 1 is recovered to the normal one.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a deterioration recovery device for photoreceptors for laser printers, copying machines, and facsimile machines.

[Conventional technology]

Fundamentals and Applications of Electrophotographic Technology, Corona Publishing (1988) Conventionally, as an example of installing a heater around a photoreceptor, see (e) Belt fixing in Electrophotographic Technology and Applications, Corona Publishing (1988), pp. 326 to 327. As discussed in the above, in both belt-type photoreceptors and drum photoreceptors, a heater is used to fix the powder toner on the paper.

[Problem to be solved by the invention]

The above-mentioned conventional technology is a heater for fixing powder toner to paper.

The present invention aims to improve the print quality of electrophotography by restoring a deteriorated photoreceptor to its normal state.

[Means to solve the problem]

In order to achieve the above object, a photoreceptor drum is placed in a light-shielded box, a heater is attached around it, and a control circuit is provided so that the surrounding temperature is 400C to 70C.

Alternatively, by inserting a drum shaft with a heater attached to the photoreceptor drum, a control circuit is provided to adjust the internal temperature of the photoreceptor drum to 40°C to 70°C. A deteriorated photoreceptor will recover if left at this temperature in a place shielded from light.

C effect] In general, a deteriorated photoreceptor has additional oxides on its surface and is expected to be attached to the photoreceptor surface by corona discharge, but σ charges cannot be attached thereto. As a result, the charging potential decreases, resulting in poor printing.

However, when the photoreceptor surface is heated from 40° C. to 70° C. by the heater, the photoreceptor receives thermal energy and removes oxides attached to the surface, thereby improving and recovering the printing quality of the photoreceptor.

[Example] An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a process block diagram of a laser beam printer. Normally, a corona discharge 3 is applied to the photoreceptor drum 1 to attach an electric charge to the surface of the photoreceptor drum unit, and a laser beam is applied to the photoreceptor drum 1 by an exposure device 5 to form an electrostatic latent image. Next, a developer 5 applies toner to the surface of the photosensitive drum 1 to form a visible image, a transfer device 6 transfers the toner to recording paper, a cleaning blade 7 removes residual toner, and an erase lamp 8 removes static electricity.

This time, a heater 2 is provided between the corona charger 3 and the exposure device 4 and between the exposure device 4 and the developer 5, and a thermostat 9 is installed between the erase lamp 8 and the corona charger 3 to control the temperature from 40°C to 70'C. It has a structure that provides When the photosensitive drum 1 has deteriorated, the developing device 5 is removed, the postsensitive drum 1 is heated to 40° C. to 70° C., and left for 3 hours or more. Second
The figure shows the heater 2 incorporated into the drum shaft 20.

Connect the drum shaft 2 so that the heater 2 cord does not become tangled.
A ball bearing 21 was provided at the base of o.

The drum shaft 20 is inserted into a hole in the center of the photoreceptor drum (shown in FIG. 1) and heated from the inside.

FIG. 3 shows an example in which the present invention is applied to a belt type photoreceptor 32. The belt type photoreceptor 32 is rotated by the roller 31. This is an example in which a heater 2 and a heater 9 are provided around it.

FIG. 4 is a circuit diagram of the present invention. Photoreceptor drum
When the belt-type photoreceptor 32 deteriorates and print quality deteriorates, the switch 41 is turned on. The heater control circuit and the timer circuit 40 control the photoconductor drum 1 and the belt-type photoconductor 32.
The ambient temperature is controlled between 40°C and 70°C. Furthermore, since the recovery time for the photoreceptor to return to normal after deterioration is 3 hours or more (see FIGS. 5 and 6 for details), the timer in the heater control circuit and timer circuit 40 is set to a 5-hour radius. This is an example of a circuit that can be disconnected.

FIG. 5 and FIG. 6 are experimental data of the present invention.

○PC (Organic photo Co.) on the photoconductor
The deteriorated OPc was placed in a thermostat in a dark room and the temperature was kept at 30'C, 5oC using an organic photoconductor.
The temperature was set at 70°C, and data on charging potential and residual potential were taken every hour and plotted on a graph.

This graph shows that the charging potential and residual potential enter the normal potential range in about 3 hours and converge to the normal range in about 5 hours when the method of the present invention (50° C., 70° C.) is used. but,
It was confirmed through experiments that the charged potential and residual potential did not recover to normal ranges at 30°C.

[Effects of the Invention] According to the present invention, there is an effect that a deteriorated photoreceptor whose printing quality has deteriorated can be recovered.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a photosensitive drum according to one embodiment of the present invention, and FIG.
3 is an explanatory diagram of a belt-type photoreceptor according to an embodiment of the present invention, FIG. 4 is a circuit diagram of the present invention, and FIG. 5 is a diagram showing a drum shaft according to an embodiment of the present invention. FIG. 6 is a diagram showing experimental data for the present invention. 2... Heater, 9... Thermostat, 4o...
Heater Figure 4 Figure 5 Figure 5

Claims (1)

[Claims] 1. Place an electrophotographic photoreceptor drum in a box shielded from light from the outside, heat the area around it with a heater, and lower the ambient temperature to 4.
Either use a thermostat to maintain the temperature between 0°C and 70°C, or insert a heater attached to the drum shaft for the photoreceptor drum to warm it from inside the photoreceptor, and use a thermostat to keep the ambient temperature at 40°C and above. A photoreceptor deterioration recovery device characterized by controlling the temperature to be maintained at 70°C.