JPH06161226A - Developing device for electrophotographic recorder - Google Patents

Abstract

PURPOSE:To stably control the resistance value of a toner carrier even in mass- production. CONSTITUTION:This developing device for an electrophotographic recorder is provided with an electrostatic latent image carrier 7 having an electrostatic latent image actualized with electrified toner 3 and the toner carrier 6 which is a roller having the formation of the rubber layer of urethane, nitrile, chloroprene, etc., that fine powder silica is equally dispersed as an addition agent, on the outer periphery of a metallic roller shaft, has 10<5>-10<8>OMEGA resistance value between the surface of a roller and a shaft, the roller surface roughness is 10mum or below and the rubber layer hardness is 25-40 deg. and supplies the toner 3 to the electrostatic latent image carrier 7. Moreover, a regulating blade 2 forming a toner thin layer on the surface of the toner carrier 6 developing the electrostatic latent image by contact with the electrostatic latent image carrier 7 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for an electrophotographic recording device, and more particularly to a developing device for a contact developing type electrophotographic recording device using a non-magnetic one-component toner.

[0002]

2. Description of the Related Art In a conventional developing device for an electrophotographic recording apparatus using a non-magnetic one-component toner, a toner thin layer is formed by adhering the toner charged by a layer thickness regulating member or the like to the surface of a toner carrier. Then, when the toner carrier and the electrostatic latent image carrier come into contact with each other, the electrostatic latent image on the electrostatic latent image carrier is developed by the thin toner layer. The additive to the rubber layer of the toner carrier for imparting conductivity is generally one in which carbon black is dispersed in an elastic roller such as silicon or chloroprene rubber.

[0003]

The toner carrier used in this conventional developing device for an electrophotographic recording device is a dispersion of carbon black in order to impart conductivity in the rubber layer, and a large amount thereof is used. The resistance cannot be reduced without adding carbon black. In addition, the resistance value of the rubber layer changes greatly and it is difficult to obtain a constant resistance value even if the amount of carbon added is changed by a very small amount, and there is a problem in mass production stability. In addition, if the amount of carbon added is increased in order to reduce the resistance value of the rubber layer, the rubber hardness becomes large and it is difficult to control the rubber hardness. If the rubber hardness is too high, the electrostatic latent image bearing member will be damaged at the contact part between the toner bearing member and the electrostatic latent image bearing member, and if the rubber hardness is too low, the contact pressure with the regulation blade will be low and toner charging There is a possibility of insufficient quantity and uneven charging.

[0004]

SUMMARY OF THE INVENTION A developing device for an electrophotographic recording apparatus according to the present invention comprises an electrostatic latent image carrier having an electrostatic latent image visualized by charged toner; A roller on which a rubber layer of urethane, nitrile, chloroprene, or the like in which fine powder silica is uniformly dispersed as an additive is formed, and the resistance value between the roller surface and the shaft is 10 or less.
⁵ to 10 ⁸ Ω, and the surface roughness of the roller is 10 μm
Hereinafter, the rubber layer has a hardness of 25 to 40 degrees and a toner carrier for supplying the toner to the electrostatic latent image carrier; and the electrostatic latent image developed by contact with the electrostatic latent image carrier. And a regulating blade for forming a thin toner layer on the surface of the toner carrier.

Further, the developing device for an electrophotographic recording apparatus of the present invention is characterized in that the regulating blade uses a spring material made of a non-magnetic thin metal plate.

Further, the developing device for an electrophotographic recording apparatus of the present invention is characterized in that a spring material made of stainless steel and phosphor bronze is used as a spring material of the non-magnetic thin metal plate of the regulation blade.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. First, the overall configuration of a developing device for an electrophotographic recording apparatus according to an embodiment of the present invention will be described with reference to FIG. A light source such as a laser or an LED (not shown) exposes image data to the electrostatic latent image carrier 7 to which an electric charge is uniformly applied by the charging brush 1 to form an electrostatic latent image. Toner hopper 9
Is arranged opposite to the electrostatic latent image carrier 7 and stores the toner 3. The toner 3 in the toner hopper 9 is agitated by the agitating member 4 and supplied to the toner carrier 6 which rotates counterclockwise by the toner supply member 5 which rotates counterclockwise. The toner supply member 5 is, for example, a urethane roller or other foam material having elasticity provided with conductivity, which is coated on the outer periphery of a metal roller. The toner 3 supplied to the toner carrier 6 is triboelectrically charged and regulated by the regulation blade 2 to form a more uniform thin layer. The regulation blade 2 is made of a non-magnetic metal thin plate spring material such as stainless steel and phosphor bronze, and the end of the regulation blade 2 is bent. The charged toner 3 which is a thin layer on the toner carrier 6 is rotated by the toner carrier 6 and the toner carrier 6 is rotated.
And an electrostatic latent image bearing member 7 (development area), and an electric field based on the potential difference between the surface potential of the electrostatic latent image bearing member 7 and the bias voltage applied to the toner bearing member 6. It moves to the electrostatic latent image on the surface of the electrostatic latent image carrier 7 to form a toner image.

FIG. 2 is a block diagram of the toner carrier 6 used in the developing device for the electrophotographic recording apparatus of this embodiment. Referring to FIG. 2, the toner carrier 6 is composed of a metal roller 11 made of stainless steel or aluminum, and a rubber layer 12 made of urethane, nitrile, crooprene, etc., which is provided with conductivity on the outer periphery thereof. Conductivity is imparted to the rubber layer 12 by adding fine powder silica made of silicon dioxide, aluminum silicate, or the like.
The hardness of the rubber layer 12 of the toner carrier 6 is determined by the regulation blade 2
Also, in consideration of the contact pressure with the electrostatic latent image carrier 7, it is 25 to 40 degrees on the JIS scale. Further, the toner carrier 6
Of the resistance between the surface of the rubber layer 12 of the toner carrier 6 and the metal roller 11 in consideration of insufficient charge injection into the electrostatic latent image carrier 7 due to lower resistance of the toner and fogging due to higher resistance. The value is preferably 10 ⁵ to 10 ⁸ Ω. The particle diameter of the negatively chargeable polyester-based toner 3 used in this example is about 10 μm, and in order to uniformly charge the toner 3, the ten-point average surface roughness of the toner carrier 6 is 10 μm or less. Is desirable. The hardness of the rubber layer 12 of the toner carrier 6 is 28 degrees, the resistance value between the surface of the rubber layer 12 and the metal roller 11 is 10 ⁶ Ω, and the surface roughness of the rubber layer 12 of the toner carrier 6 is 4 μm. When a polyester non-magnetic single-component toner is used as the toner, the regulation blade 2 is made of a stainless spring material having a thickness of 0.1 mm, and the contact pressure of the regulation blade 2 is 12.6 g / mm ² , the amount of the toner layer is 0. 6 to 0.7 mg / cm ² with a charge amount of 11 μC
/ G was stable and good. Regarding the print quality, the image density in the solid black portion was stable at 1.4, and the character resolution was also good.

[0009]

As described above, according to the present invention,
The toner carrier used in the developing device for an electrophotographic recording device is a roller on which a rubber layer of urethane, nitrile, chloroprene or the like in which fine powder silica is evenly dispersed as an additive is formed on the outer periphery of a metal roller shaft, The resistance value between the surface and the shaft is 10 ⁵ to 10 ⁸ Ω, the roller surface roughness is 10 μm or less, and the rubber layer hardness is 25 to 40 degrees, so that the resistance value of the toner carrier is stable even during mass production. Control is possible, and there is no problem that rubber hardness increases. Therefore, it is possible to reliably supply the toner to the electrostatic latent image while maintaining an appropriate contact pressure between the toner carrier and the regulation blade and between the toner carrier and the electrostatic latent image carrier. Therefore, the electrostatic latent image carrier can be prevented from being damaged and the electrostatic latent image carrier can have a long life.
Further, since the metallic regulation blade such as stainless steel can be brought into contact with the toner carrier with an appropriate pressure contact force,
It is possible to supply an appropriate amount of the toner layer to the toner carrier while charging the toner by the required amount. Further, since a large amount of carbon is not required and strict control is not required in the manufacturing process, it leads to cost reduction.

[Brief description of drawings]

FIG. 1 is a sectional view of a developing device for an electrophotographic recording apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a toner carrier in the example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Charging brush 2 Control blade 3 Toner 4 Stirring member 5 Toner supply member 6 Toner carrier 7 Electrostatic latent image carrier 8 Cleaner 9 Toner hopper 11 Metal roller 12 Rubber layer

Claims (3)

[Claims] 1. An electrostatic latent image carrier having an electrostatic latent image visualized with charged toner; urethane, nitrile and chloroprene in which fine silica powder is uniformly dispersed as an additive on the outer periphery of a metal roller shaft. A roller having a rubber layer formed on the surface of the roller and the shaft has a resistance value of 10 ⁵
10 is ⁸ Omega, the surface roughness of the roller is 10μm or less, wherein a rubber layer hardness is 25 to 40 degrees, the toner carrying member for supplying the toner to the electrostatic latent image bearing member and; the electrostatic A developing device for an electrophotographic recording apparatus, comprising: a regulating blade that forms a thin toner layer on the surface of the toner carrier that develops the electrostatic latent image by contact with the latent image carrier. 2. The developing device for an electrophotographic recording apparatus according to claim 1, wherein the regulating blade uses a spring material made of a non-magnetic thin metal plate. 3. The developing device for an electrophotographic recording apparatus according to claim 2, wherein a spring material made of stainless steel and phosphor bronze is used as a spring material of the non-magnetic thin metal plate of the regulation blade.