JPH01297695A - Electrophotographic copying device - Google Patents

Abstract

PURPOSE:To prevent the stain of a wire by providing a brush of light shielding resin between a main destaticizing device performing exposure and eliminating the residual electric potential of a photosensitive body of amorphous silicon before the process of main electrostatic charge and after being cleaned and eliminating it and a main electrostatic charging unit. CONSTITUTION:The brush of light shielding resin 7b is provided between the main destaticizing luminous source 9 of the main destaticizing device performing exposure and eliminating the residual electric potential of the photosensitive body of amorphous silicon 1 and the main electrostatic charging unit 2. That means, since the brush of light shielding resin 7b exists between the main destaticizing luminous source 9 and the main electrostatic charging unit 2, the irradiating position of destaticizing light is made to be far from the main electrostatic charging unit 2. As the result of that, the ability to eliminate ghost is increased and simultaneously the lowering of destaticizing ability is decreased and a substance atomized and splashed by a cleaning device 7 is prevented from flowing into the main electrostatic charging unit 2 just before it by the brush 7b. Thus, an electrophotographic copying device of which wire is prevented from being stained and of which total ability is excellent is obtained.

Description

Detailed Description of the Invention [Industrial Application] The present invention relates to an electrophotographic device using an amorphous silicon photoreceptor, and particularly to an electrophotographic device that prevents wire contamination and improves charging ability of the electrophotographic device. The present invention relates to a main static eliminator that is designed to achieve the following objectives.

[Background of the Invention] Amorphous silicon photoreceptors have high surface hardness, exhibit high sensitivity to long-wave light such as semiconductor lasers (770 nm to 800 nm), and rarely exhibit deterioration due to repeated use. Especially high-speed copying machines and LBP
It has been praised as a photoreceptor for electrophotography (laser beam printers) and other devices.

However, such an amorphous silicon photoreceptor has many dangling bonds (dangling bonds), which become localized levels and capture a part of the photochiaria, reducing its running properties. , or reduce the recombination probability of photogenerated carriers. In this way, if the main charge-eliminating light for ghost erasing is too strong because it is susceptible to optical memory, the excess carriers latent inside the photoreceptor will enter the main charging process before recombining, reducing the charging efficiency. This had the disadvantage of significantly reducing the In other words, in the charging process, the initial stage is a carrier recombination process, and then there is a step of increasing the surface potential, so the amount of carriers in the photoreceptor immediately before the charging process affects the subsequent level of surface potential, that is, the charging ability. greatly affects.

Therefore, it is desirable that the main neutralizing light be emitted a certain period of time before the main charge, erase the optical memory during image formation, and proceed to the charging step after the carriers have been generally recombined.

However, in high-speed copying machines, there are many spray particles from the cleaner that adhere to the wire of the main charger, causing uneven charging and density unevenness such as halftones. In order to prevent this, a brush woven from acrylic fibers or the like is brought into contact with the photoconductor to capture submicron-order fine particles (silica, polyvinylidene butt, etc. in toner) through frictional charging and mechanical collection. collected and prevented from flowing into the main charger. It is difficult to make the length and light transmittance of these brushes the same, and if the main static eliminator light is irradiated very close to the brush, the amount of static eliminator light will change depending on the positional accuracy of the brush, leading to uneven charging, and the cleaner of the main static eliminator light will It was an obstacle to moving to the side.

On the other hand, if this brush is removed and the main static elimination light is brought close to the cleaner, it is difficult to ensure orthogonal incidence to the photoreceptor, so It was found that because the light was reflected and leaked toward the main charger, the charging ability did not improve even though the peak of the irradiation light was moved far away from the main charger. This may be due to the ghost elimination mechanism being smoothed out by carriers generated in excess, or the carriers generated by low-intensity light such as reflected light from the main static elimination light source after the main irradiation can eliminate the aforementioned ghosts. In many cases, the incident position on the photosensitive layer is moved closer to the main charger due to repeated reflections, and the charging ability is not only adversely affected by lowering the charging ability. Research conducted by the present invention has revealed that the effects of this disease frequently result in a decrease in performance.

[Prior Art] A conventional electrophotographic apparatus of this type has a configuration as shown in FIG. 2, for example.

In FIG. 2, 1 is an amorphous silicon photoreceptor, 2
3 is a main charger, 3 is an image information providing means, 4 is a developing device, 5 is a transfer charger, 6 is a separation means, 7 is a cleaning device, 7
C is a cleaning blade, 7d is a collection brush, and 8 is a main static elimination light source.

That is, around the cylindrical amorphous silicon photoreceptor 1 that rotates in the X direction and rotates in a direction perpendicular to the plane of the paper, there is a main charger 2 that is close to the photoreceptor 1 and uniformly charges the photosensitive layer on the surface of the photoreceptor. An image information imparting means 3 for forming an electrostatic latent image, a developing device 4 for developing the latent image, a transfer charging device 5 for transferring the developed image onto a transfer material, and a transfer material for transferring the transfer material to the photoreceptor 1.
A separating means 6, a cleaning device 7, and a main neutralizing light source 8 are arranged in parallel.

Further, in the cleaning device 7, one flM H& edge of a cleaning blade 7C made of a suitable elastic material such as urethane rubber is in pressure contact with the counter direction or the trailing direction, and does not contribute to the transfer at the transfer site. The residual toner remaining on the surface of the photoreceptor 1 is removed by the blade 7.
When reaching position C, the particles are scraped off from the surface, and the atomized submicron particles that have passed through are collected by a collection brush 7d made of acrylic nylon or the like.

In particular, an LED array whose wavelength and light amount can be precisely controlled is used for the main static eliminating light of the main static eliminating light source 8 in order to eliminate ghosts and ensure charging performance.

[Problem to be solved by the invention] In the conventional electrophotographic apparatus shown in FIG. However, there is a problem in that the charging ability becomes low, and in some cases, due to limitations in the charging ability, it is necessary to weaken the static elimination light to eliminate ghosts.

The present invention attempts to solve these problems. That is, the present invention maximizes the ghost erasing ability of the main static eliminating light, which is essential for ghost erasing, and
The purpose of the present invention is to provide an electrophotographic device with excellent overall performance, which minimizes deterioration in charging ability, simultaneously prevents spray particles from the cleaner from flowing into the main charger, and prevents wire contamination. It is.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an electrophotographic apparatus using an amorphous silicon photoreceptor, in which the residual potential of the photoreceptor after cleaning before the main charging step is reduced by exposing the photoreceptor to light. A light-shielding resin brush was installed between the main charger and the main static eliminator.

[Function] According to the present invention, since the light-shielding resin brush is provided between the main static eliminator and the main charger, the irradiation position of the static neutralization light becomes that far from the main charger, and therefore, the ghost can be eliminated. As the capacity increases, the deterioration in charging capacity is also reduced, and the flow of spray particles from the crease into the main charger is prevented.

[Example] FIG. 1 shows an embodiment of the invention.

In FIG. 1, numerals 1 to 7 are the same members as in FIG. 2. Further, 7a is a cleaning blade made of an elastic material such as urethane rubber, 7b is a light-shielding resin brush, and 9
is the main static eliminator light source of the main static eliminator.

That is, the light-shielding resin brush 7b is provided between the main charger 2 and the main charger 2 of the main charger, which exposes and erases the residual potential of the amorphous silicon photoreceptor 1.

In the electrophotographic apparatus configured as shown in FIG.
Because of the presence of b, the irradiation position of the static eliminating light becomes farther from the main charger 2, increasing the ghost erasing ability and reducing the deterioration of the charging ability.
The brush 7b prevents the spray particles from flowing in immediately in front of the main charger 2.

[Experiment Example 1] The diameter of the amorphous silicon photoreceptor 1 shown in Fig. 1 is 108 cm.
, the process speed is 340m+a/sec.

The photoreceptor 1 used was one in which a 27 μm thick amorphous silicon photosensitive layer was deposited on an aluminum cylinder. Next, as shown in FIG.
ec) on the surface of the photoreceptor 1 at 610 am and 71
Static neutralizing light of ux, sec was irradiated. At this time, the first
The results are shown in Table (A).

Table 1 [Experiment Example 2] Conventional configuration shown in Figure 2 (65 degrees to main charger 2, O, 18
sec), the degree of charging ability, ghost, and wire contamination obtained under the same conditions as in Experimental Example 1 was
The results are shown in Table (B).

[Experiment Example 3] In the configuration shown in Figure 1, carrier recombination time is 60%.
By increasing the charge, an improvement in charging ability of about 20 V was observed with the same static eliminating light and the same current value. Also, in order to achieve the same potential with the same current value, it is necessary to adjust the amount of static electricity removal light.
In this case, ghosts are reduced in the conventional system. Furthermore, the light-shielding resin brush 7b significantly increased the number of halftone images in which streaks began to appear.

[Effects of the Invention] As explained above, according to the present invention, a light-shielding resin is provided between the main charger and the main static eliminator that exposes and erases the residual potential of the amorphous silicon photoreceptor after cleaning before the main charging step. The provision of a brush maximizes the ghost erasing ability of the main static eliminating light, which is essential for ghost erasing, and minimizes the deterioration of charging ability, while at the same time preventing the spray and debris from the cleaner from entering the main charger. It has now become possible to provide an electrophotographic device with excellent overall performance, which prevents the inflow of wires and prevents wire contamination.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional front view showing an embodiment of the present invention, and FIG. 2 is a cross-sectional front view showing an example of a conventional technique. 1...Amorphous silicon photoconductor 2...Main charger 7...Cleaning device 7b...Light-shielding resin brush 9...Main static elimination light source

Claims (1)

[Claims] 1. In an electrophotographic apparatus using an amorphous silicon photoreceptor, a light-shielding resin brush is provided between the main charger and the main static eliminator that exposes and erases the residual potential of the photoreceptor after cleaning before the main charging step. An electrophotographic device comprising: