JPH09146430A - Electrophotographic equipment - Google Patents

Abstract

(57) Abstract: An electrophotographic apparatus provided with a static eliminator for extending the life of a photoreceptor. When the exposure energy of a static eliminator 12 for erasing a latent image on a photoconductor 3 is E1 and the exposure energy of a light source used for forming a latent image is E2, E1, E2
Is 5 × E2> E1 ≥E2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus that forms an image using a photoconductor.

[0002]

2. Description of the Related Art In electrophotographic processes such as copying machines and printers, in order to prevent the afterimage (residual potential) of the pre-printing process from appearing in the image, a static eliminator applies static elimination energy to the photoconductor to remove the residual potential. There is a process to do so. This step is performed after the visible image formed on the photoconductor is transferred to printing paper, etc., and before the photoconductor is recharged by the charger for the next printing cycle. The purpose is to make the surface potential of the previous photoreceptor uniform. Here, the value of the surface potential of the photoconductor after the transfer is completed, that is, the value of the residual potential is approximately between the charging potential (V0) and the potential (VL) of the latent image forming portion when black printing is performed on the entire surface. Therefore, in order to make the residual potential uniform, it is necessary to lower the photosensitive member surface potential to VL or less. Conventionally, if the energy on the photoconductor surface of the static eliminator is E1 and the energy of the light used to form a latent image on the photoconductor surface is E2, then E1 >> E2 (E1 Excessive static elimination energy was supplied so that> 5 x E2).

[0003]

However, the supply of such excessive static elimination energy to the photoconductor has a problem that the photofatigue of the photoconductor is promoted and the life of the photoconductor is shortened. .

The present invention solves the above-mentioned problems of the prior art, and provides an electrophotographic apparatus equipped with a neutralization device capable of extending the life of a photoreceptor and maintaining a good image for a long period of time. It is an object.

[0005]

In order to solve the above-mentioned problems, the electrophotographic apparatus of the present invention uses the energy E1 on the surface of the photoconductor during the charge removal of the charge removal means and the irradiation means for forming an electrostatic latent image. The energy E2 of the light on the photoconductor surface is 5 ×
The relationship of E2> E1 ≧ E2 is established. With this configuration, an electrophotographic apparatus equipped with a neutralization device capable of extending the life of the photoconductor and maintaining a good image for a long period of time can be obtained. .

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is directed to a photoconductor on which an electrostatic latent image is formed, a charging means for charging the photoconductor, and a light to the charged photoconductor. Irradiation means for irradiating to form an electrostatic latent image, developing means for developing the photoconductor on which the electrostatic latent image is formed with a developer, and a visible image by the developer formed on the photoconductor as a recording medium. A transfer unit for transferring the charge to the photoconductor and a charge removal unit for removing the charge on the photoconductor, and the energy E1 on the surface of the photoconductor in the charge removal of the charge removal unit and the energy E2 on the surface of the photoconductor of the light from the irradiation unit. The relationship of 5 × E2> E1 ≧ E2 is established, and it has an effect of preventing image defects due to light fatigue of the photoconductor and extending the life of the photoconductor.

According to a second aspect of the present invention, in the first aspect of the present invention, the charge removing means removes the charge of the photoconductor by light energy, and has the same effect as that of the first aspect.

According to a third aspect of the present invention, in the first aspect of the present invention, the charge removing means removes the charge of the photoconductor by electric energy by corona charging, and has the same function as that of the first aspect. .

The structure of a non-magnetic one-component electrophotographic apparatus will be described below as an example of the electrophotographic apparatus using the static eliminator of the present invention. FIG. 1 is a schematic configuration diagram of a non-magnetic one-component electrophotographic apparatus. In FIG. 1, a metal drum made of aluminum or the like is used as a base material, and a photoreceptive layer such as selenium (Se) or an organic photoconductor (OPC) is thinly applied on the outer peripheral surface thereof in proximity to the photoconductor 3. The charging device 2 provided is composed of a charging wire 2a such as a tungsten wire and a metallic shield plate 2b. In the charger 2, the charging wire 2a causes corona discharge to uniformly charge the photoconductor 3.
Reference numeral 5 denotes a developer supply member (hereinafter referred to as a toner supply roller) which is rotatably supported by the main body housing 24 and supplies the toner 6 stirred and conveyed by the toner stirring member 7 formed into a rectangular shape to the surface of the developing roller 4. The developing roller 4 and the toner supplying roller 5 are made of metal such as stainless steel as a base material, and members such as urethane and silicon are formed in layers on the outer peripheral surface of the developing roller 4 and the toner supply roller 5, and are rotatably supported on both sides of the main housing 24. There is. Further, both ends of the developing roller 4 are provided with seals 10 at both ends of the developing roller in order to prevent the toner 6 from leaking. The toner 6 supplied by the toner supply roller 5 is triboelectrically charged by the developing blade 9 formed of a member such as urethane or silicon, is thinned on the outer peripheral surface of the developing roller 4, and contacts the photoconductor 3. By applying a voltage from the developing bias power source 23 to the developing roller 4, the latent image forming means (not shown) transfers and adheres to the electrostatic latent image portion formed on the photoconductor 3 to visualize the electrostatic latent image. To do. The toner stirring member 7 draws a locus of a circle indicated by a thin line as the toner supply roller 5 rotates, and conveys the toner 6 put into the developing device toward the toner supply roller 5. Reference numeral 8 is a member to which the developing blade 9 is attached. Reference numeral 1 is a sealing material that prevents toner from leaking from the developing device. 11
Is a cleaning blade for scraping off the residual toner on the photoconductor 3. Reference numeral 12 is a static eliminator of the present invention, which is a device for removing charges remaining on the photoconductor 3. Further, the transfer papers 13 stored in the copy paper cassette 14 are sent from the copy paper cassette 14 to the transport rollers 16 one by one by a half-moon shaped paper feed roller 15.

The transfer sheet 13 sent out is conveyed by a conveying roller 16
Is conveyed in the direction indicated by the arrow. Reference numeral 17 denotes a registration roller for temporarily stopping and waiting the transfer paper 13 in order to make the transfer paper 13 and the toner image formed on the photoconductor 3 coincide with each other, and is in contact with the driven roller 18. The transfer roller 19 has a columnar shape as a whole, and includes a shaft 19a made of stainless steel or the like as a core material and a sponge-like elastomer 19b in which carbon or the like is dispersed, and is installed so as to have a constant nip width with the photoconductor 3. Has been done,
The toner image on the photoconductor 3 is transferred onto the transfer paper 13 by applying a bias having a polarity opposite to that of the toner 6 to the shaft 19a. The transfer roller 19 is fixed to the main body housing 24 via a bearing, and is freely rotatable. The distance between the shaft 19a of the transfer roller 19 and the shaft 3a of the photoconductor 3 is the sum of the radius of the transfer roller 19 and the radius of the photoconductor 3, and the transfer roller 19 that is an elastic body is the photoconductor. It is set to the length less the amount of bite into 3. The toner image transferred onto the transfer paper 13 is rotated by the fixing device 20 including a heat roller 21 and a pressure roller 22 having a heat source therein as the heat roller 21 and the pressure roller 22 are nipped and rotated. The transfer paper 13 is fixed by pressure and heat.

As a concrete example, a light emitting diode array is used as a light source for forming a latent image in the electrophotographic apparatus shown in FIG. 1, and the energy of the light is E1 = E1 = 0.7 μJ / cm ² , a light emitting diode is used for the static eliminator 12, and the energy of the light is E 2 = 4.5, 0.8, 0.3 μJ / cm ² on the surface of the photoconductor 3.
Change the relationship between 1 and E2 to change the initial and full black print to 1000.
The surface potential of the photoconductor 3 after printing 0 sheets and the evaluation result of the output image were performed. The evaluation results are shown in (Table 1).

[0012]

[Table 1]

The photoconductor 3 used was a negatively chargeable organic photoconductor, and the surface potential (V0) of the photoconductor 3 after completion of charging was set to -700V at the start of the experiment. The developing roller 4 is a conductive silicon rubber containing carbon black, and its resistance value is adjusted to about 10 ⁶ Ω · cm, and the developing roller 4 is arranged so as to bite into the photoconductor 3 by 1 mm. The toner 6 used in the experiment is a styrene acrylic negatively-charged toner, and the toner 6 has a particle size of 8 μm (vol · 50%). The development method was non-magnetic one-component contact development, and reversal development was performed.

[0014]

As described above, according to the present invention, the life of the photoconductor can be extended, and as a result, a good image can be maintained for a long period of time.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a non-magnetic one-component electrophotographic apparatus.

[Explanation of symbols]

 1 Sealing Material 2 Charging Device 3 Photosensitive Member 4 Developing Roller 5 Toner Supplying Roller 6 Toner 7 Toner Stirring Member 8 Member 9 Developing Blade 10 Developing Roller End Seal 11 Cleaning Blade 12 Static Electrifier 13 Transfer Paper 14 Copy Paper Cassette 15 Paper Feeding Roller 16 Conveyor Roller 17 Registration Roller 18 Followed Roller 19 Transfer Roller 20 Fixer 21 Heat Roller 22 Pressure Roller 23 Development Bias Power Supply 24 Main Body Housing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Noda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Tetsuhiro Tsuru, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. A photosensitive member on which an electrostatic latent image is formed, a charging unit for charging the photosensitive member, an irradiation unit for irradiating the charged photosensitive member with light to form an electrostatic latent image, and a static unit. Developing means for developing the photoconductor on which the latent image is formed with a developer,
Energy transfer means for transferring a visible image formed by a developer formed on the photoconductor to a recording medium, and a destaticizing means for destaticizing the photosensitive body, and energy E1 on the surface of the photosensitive body in destaticizing the destaticizing means, An electrophotographic apparatus wherein the energy E2 of the light of the irradiation means on the surface of the photoconductor is 5 × E2> E1 ≥E2. 2. The electrophotographic apparatus according to claim 1, wherein the charge removing unit removes charge from the photoconductor by light energy. 3. The electrophotographic apparatus according to claim 1, wherein the charge eliminating unit removes electricity from the photoconductor by electric energy generated by corona charging.