JPS59155861A - Particle removing device - Google Patents

Abstract

PURPOSE:To form particles on a particle supporting body to a single layer by providing a particle removing roller opposed to the particle supporting body, and a cleaning electrode opposed to the particle removing roller, and impressing a prescribed voltage. CONSTITUTION:The surface of a photosensitive layer 10b is electrostatically charged to negative by a corona electrifier 12, by a rotation of a photosensitive drum 10, and when it reaches a position opposed to a lower opening part 13a of a hopper 13, particles 11 are attracted and made to adhere onto a photosensitive layer 10b. When particles of a lot of layers on the photosensitive layer 10b reach a position opposed to a removing roller 15, the particles are attracted to the particle removing roller 15 by the positive potential impressed to the photosensitive drum 10, and only a single particle layer is left on the photosensitive layer 10b. As the removing roller 15 rotates, the particles are attracted to a cleaning electrode 16 which is opposed to the removing roller 15 and to which the positive potential is impressed, and most of particles are collected into the hopper 13.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention uses, for example, light-transmitting particles and an electrophotographic photoreceptor to generate a latent image on the photoreceptor depending on the amount of light transmitted through each particle. Related to a particle removal device for layering particles or developing, which is applied to an image forming method that selectively removes particles to obtain a particle image The image forming method requires a development step to remove the odor.

Conventionally, methods used for layering particles on a support and for development include methods using air jets in electronic marking methods, and methods such as those described in Japanese Patent Publication No. 56-2338. There are methods such as applying vibration to the support to cause particles with weak adhesion to fall. These methods are
In order to completely remove unnecessary particles without affecting the necessary particles that should remain on the support, delicate adjustments are required in the way air is blown and the way vibrations are applied, and in order to obtain a good image. is technically extremely difficult. Even if it were possible, if these were made into a device, the device would be complicated and large, and it would cause vibrations. There were problems such as noise generation.

Another method is to use a dielectric roller and plate as shown in FIG. In the figure, the dielectric body 2 charged by the corona charger 1 electrostatically attracts unnecessary particles having weak electrostatic adhesion to the support body 3 at a position opposite to the support body 3. Particles adhering to the dielectric 2 are scraped off by the brake l·4 which is pressed against the dielectric 2. This method d
Although the structure is simple, since a blank notebook is used to clean the dielectric, it has the following drawbacks.

In other words, the particles that have been scraped off by the grade and stored in the collection box 5 are often widely damaged, so especially when the shape and surface condition of the particles affect the image, such as light-transmitting particles. Cannot be reused.

Unfortunately, because the blade and dielectric are constantly in friction, the blade end face and the dielectric surface are easily damaged, and scratches on the dielectric surface will affect the electric field distribution in the area where the dielectric and the support face each other. This can result in non-uniform electric field distribution, which can affect the image, and can also affect the lifespan of the blade or dielectric itself. Furthermore, there are -1- particles that are not completely removed by the blade and remain on the dielectric material, but when they pass through the corona charger as the dielectric material rotates, they are charged and spread, so that the dielectric material and support are When the size of the opposing part reaches , the electric field in this part attracts the chair toward the support, and the chair falls onto the support, which may hit the necessary particles and disturb the image.Object of the Invention SUMMARY OF THE INVENTION An object of the present invention is to provide a particle removal device for single-layer layering or development, which overcomes the drawbacks of the prior art. In other words, it is a device that removes particles from the second layer and above, which have a weak static adhesion to the support, from among particles dispersed in multiple layers on a charged support, and forms the particles on the support into a single layer. This process is especially essential for image forming methods using light-transmitting particles. Another object of the present invention is to provide a developing device that selectively leaves particles in accordance with an electrostatic layer image formed on an electronic intuitive light body or an electrostatic recording body and removes other unnecessary particles.

Structure of the Invention The present invention comprises a support for particles, a rotatable particle removal roller 7j facing the support with a gap, and a particle removal roller facing the support with a gap on a side substantially opposite to the support. This is a particle removal device that removes unstable particles from the support -1- by creating a potential difference in the same direction between the support and the particle removal roller and between the particle removal roller and the electrode.

DESCRIPTION OF EXAMPLES Hereinafter, examples of layering particles on a support according to the present invention will be described based on the drawings. Figure 2 shows an example of one point hj.
It consists of an internal metal roller 10a and a photosensitive layer 10b made of 1 lead oxide coated on its outer peripheral surface. 11
are particles used in Examples.

As the photosensitive tram rotates 100 times, the surface of the photosensitive layer 1ob is sequentially negatively charged by the corona charger 12. The lower opening 13 of the charged photosensitive layer 10b or particle E, /:13
a [When the particles near the drum reach the opposing position, they are attracted and adhered onto the photosensitive layer 10b by electrostatic attraction, and a large number of layers of particles gather on the surface of the photosensitive layer and move as the drum rotates. 14 is a thin plate made of mylar or silicone rubber, which is fixed to the open end of the hopper 13,
This fills the gap between the photoreceptor drum 1o and the photoreceptor drum 1o to prevent particles from leaking.

When the particles in the multiple layers on the photosensitive layer 10b reach the position facing the particle removal roller 16vC, the particles in the upper layer, which have weak electrostatic adhesion to the photosensitive layer 10b, are suspended between the particle removal roller 15 and the photoreceptor drum 10. Particle removal roller 1
It is attracted towards 5.

In the embodiment, the metal roller 15at inside the particle removal roller
/( applies a positive potential to the photoreceptor drum. At this time, in order to leave only the particles in the first layer and the particles in the second layer and above, it is necessary to use an appropriate electric field strength, but the particle As the conductivity of the VC increases, the difference in the ease of attraction between the first and second layers increases, so when highly conductive particles are used, it becomes easier to form a single layer of VC.

The outer periphery 15b of the particle removal roller 15 is made of a semiconductor such as zinc oxide or the like, and the particles sucked here are transferred to the hopper 13 according to the rotation of the one-year-old particle removal roller 15 deposited on the surface. will be transferred to Reference numeral 16 denotes a cleaning electrode, to which a positive potential is applied with respect to the -2 particle removal roller 15, and particles on the particle removal roller 15 that reach this vicinity are attracted toward the cleaning electrode 16 by the electric field. be done. The tip of the electrode 16 is made very thin to increase the electric field strength between it and the particle removal roller 15, and the particles flying toward the cleaning electrode 16 are
The particle removal roller receives a positive charge when the particle hits the particle, and the proportion of particles that are attracted to the particle removal roller is extremely small. Therefore, most of the particles are collected in the hopper 13.

In the manner described above, the particles on the photosensitive layer 10b, which is a support, are layered. Reference numeral 17 shows exposure of the photosensitive layer 10b through the particles when light-transmitting particles are used.

FIG. 3 shows another embodiment of single-layer particle formation, in which a plurality of thin wires are used as the cleaning electrode 18. By using a plurality of thin wires, the strength of the electric field between the cleaning electrode and the particle removal roller 15 is reduced, and the time that the particles are exposed to the electric field is increased, thereby increasing the particle removal ability. be. That is, if the electric field strength is the same, particles can be completely removed by rotating the particle removal roller 16 at a higher speed.
Process speed can be increased.

Next, an embodiment in which the present invention is applied to a total developing device will be described with reference to FIG. When an image pattern is exposed from above the light-transmitting particles 11 electrostatically adhered to the photosensitive layer 10b-J2 in the direction of the arrow 17, the photosensitive layer 10 is exposed according to the image pattern.
In b, there are parts where the charge is weak or has disappeared, and parts where the charge remains strong. Particle removal roller 1
5', some particles are removed depending on the strength of the residual charge, while others of 1 inch remain, forming a particle image on the photosensitive layer 10b in accordance with the exposure pattern. 18' beam I
J'ning electrode, 19 is a particle collection box, and their operation is the same as in the previous embodiment.

FIG. 5 is an explanatory diagram of the behavior of the particles 11 when a semiconductor such as instant lead oxide is used for the outer peripheral portion 15b of the particle removing roller 15. Forming a conductive film such as CuI on the surface of the particles 11,
When using a semiconductor such as zinc oxide for the outer peripheral portion 15b, 1
Compared to the case where a normal dielectric material is used for 5b, particles are more easily attracted even if the same electric current f☆ is applied to the cleaning electrode. Although the detailed cause of this is unknown, it is presumed as follows.

In a normal dielectric, particles attached to the outer peripheral part 15b carry a negative charge when they are attracted from the photosensitive layer 10b, so when they face the cleaning electrode 18, they are attracted again according to the electric field there. However, the attractive force depends on the charge l remaining on the particle at that time. On the other hand, in the case of semiconductors such as zinc oxide, the situation seems to be as follows. In the state where the particles 11 have arrived at the outer peripheral part 15b, the CuI of the particles
It is generally considered that the zinc oxide of the outer peripheral portion 15b forms a PN junction. Since it is difficult for positive electricity to be injected from the outer periphery 15b to the particles having negative charge from the photosensitive layer 10b and in contact with the outer periphery 15bllIC, the outer periphery 15b and the support 10
The particles become negatively charged in the electric field between b and 11, but when they come to the part facing the electrode 18, they receive an electric field opposite to the previous one, so the outer peripheral part 15b is oxidized as shown by the arrow. Injection of negative charge from the zinc to the CuI of the particles occurs and the force with which the particles are attracted to the cleaning 7E electrode 18 becomes stronger. Therefore, it is thought that particles are more easily removed even if the electric field strength is the same.

Effect of the invention The prevention of non-explosion has the following effects:

(1) Since particles can be removed simply by applying voltage to the rotating particle removal roller and cleaning electrode, a small, lightweight, and inexpensive device can be constructed.

(2) Since the particle suction force is generated by the electric field between the support and the particle removal roller and between the particle removal roller and the cleaning electrode, the removal force is more uniform compared to methods such as air shed, vibration method, or blade. Moreover, since it is always stable, stable particle removal is facilitated without affecting the particles that should remain on the support.

(3) Less noise compared to vibration methods etc.

(4) Compared to methods using blades, etc., there are no frictional parts, so the service life is longer.

(5) Since the removed particles are hardly damaged, they can be reused.

[Brief explanation of the drawing]

Figure 1 shows the configuration of a conventional developing device, Figures 2 and 3.
The figure shows the configuration of an embodiment in which the present invention is applied to a particle layering device. Figure 4 shows the configuration of an embodiment in which the present invention is applied to a developing device. Figure 5. Vi outer periphery of the particle removal roller. FIG. 3 is a diagram illustrating the behavior of particles when a semiconductor is used for the purpose of the present invention. 10-... Photosensitive drum (support), 10b, photosensitive layer,
11... Particles, 15, 15'... Particle removal roller, 15b Outer circumference, 16, 18, 18'...
...Cleaning electrode. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure 2 Figure 3 Figure 4/7

Claims (3)

[Claims] (1) A support for particles, a rotatable particle removal roller with four supports facing each other with a gap provided between the supports, and a position scraped from the opposing portion of the support and the particle removal roller,
A cleaning electrode is provided facing the particle removal roller V with a gap therebetween, and a potential difference is provided in the same direction between the support and the particle removal roller and between the particle removal roller and the cleaning electrode, respectively. A particle removal device characterized by: (2) The particles are conductive and the particle removal roller
The particle removal device according to claim 1, wherein the surrounding MIS is used as a biological pest. (3) The particle removal device according to claim 1 or 2, wherein the cleaning electrode is configured by arranging a plurality of wires in parallel.