JPS61173273A - Developing device - Google Patents

Abstract

PURPOSE:To uniformly charge electrostatically the developing agent that is traveling between a carrier member and a control roll member by forming the surface of at least one of said carrier member and control roll member with a semiconducting material so that development process of images is performed uniformly. CONSTITUTION:The control roll member 5 is rotating at such a speed that a relative speed occurs between surfaces of the control roll member 5 and the carrier member 1 so that the layer of the developing agent caught on the surface 1a of the carrier member 1 is adjusted to have a uniform thickness. Further, a voltage is impressed across said members 1 and 5 by a voltage impressing means 7, thus in the layer of the developing agent with an adjusted thickness, the prescribed electrostatic charge is performed by said voltage. At least one of surfaces 1a and 5a of the members 1 and 5 is made of a semiconducting material, no undesirable spark discharge is occurred between the surfaces 1a and 5a of both members, when the voltage is impressed. As a result, uniform charge is performed in the developing agent layer, and the uniform development of electrostatic latent images 15 free from unevenness is assured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a developing device for developing an electrostatic latent image using a one-component developer.

(Prior Art) Conventionally, as disclosed in Japanese Patent Application Laid-open No. 47-13088 and Japanese Patent Application Laid-open No. 53-167341, a developer is conveyed to a holder by a carrier and the static electricity on the holder is Non-magnetic-component developing devices are known for developing electrostatic latent images into visible images. In such an apparatus, a regulating roll member is disposed in order to regulate the layer thickness of the developer carried by the carrier to a predetermined thickness, and furthermore, a regulating roll member is provided between the carrier and the regulating roll member. There is one in which a voltage is applied to charge the developer that has passed between the two.

(Problems to be Solved by the Invention) However, in the case where a voltage is applied between the carrier and the regulating roll member, if the surface of the developer carrier has unevenness, the difference between the two may occur. Spark discharge occurs, and as a result, there is a risk that the developer between the two may not be uniformly charged.

An object of the present invention is to provide a developing device that solves these problems.

(Means for Solving the Problems) For this purpose, in the developing device according to the present invention, the surface of at least one of the developer carrier and the regulating roll member is formed of a semiconductive member.

That is, as shown in FIG. 1, the present invention comprises a developer carrier] and a layer of developer 3 disposed at a predetermined distance from the carrier and carried by the carrier. It has a regulating roll member 5 that regulates the thickness to a predetermined thickness, and a voltage is applied between the carrier 1 and the regulating roll member 5 by a voltage applying means 7, and between the two parts JtA' I, 5. In the developing device for charging the developer 3 passing through the developing device, the surface 1a, 5a of at least one of the developer/carrier 1 and the regulation roll member 5 is formed from a semiconductive material. It is something.

(Function) Referring to FIG. 1, the developer 3 is supplied from the developer storage section 9 to the surface 1a of the carrier 1.

When the carrier 1 rotates in the direction of the arrow, the layer of developer 3 carried on its surface 1a is conveyed to the regulating roll member 5 in the direction L-1. This regulation roll member 5 is the carrier 1
It rotates at such a speed that a relative velocity occurs with respect to
The surface 1a of the carrier 1 is controlled by the regulating roll member 5.
The developer layer 1 is adjusted to have a uniform thickness. Furthermore, a voltage is applied between these two members 1.5 by voltage applying means 7. Therefore, the developer layer whose layer thickness has been adjusted is charged to a predetermined level by this voltage. Here, since at least one of the surfaces 1a and 5a of both members 1.5 is formed of a semiconductive material, undesired spark discharge will not occur between the surfaces 1a and 5a when a voltage is applied. do not have. Therefore, the developer layer is uniformly charged. Next, the developer layer that has passed through the arrangement position of the regulation roll member 5 is transferred to the carrier 101! The continued rotation leads to a close portion 13 with the electrostatic latent image holder 11 . The holding body 11 is
It rotates in the direction of the arrow, and an electrostatic latent image 15 is held on its surface 11a. Therefore, in this proximal portion 13, the developer layer adheres to the electrostatic latent image 15 on the carrier surface 11a, thereby making the latent image 15 visible. Here, since the developer layer is uniformly charged as described above, the electrostatic latent image 15 is developed evenly and uniformly.

(Effects of the Invention) As described above, in the present invention, since the surface of at least one of the carrier and the regulating roll member is formed from a semiconductive material, there is no possibility that undesired spark discharge will occur between these two members. Therefore, the developer passing between these two members can be uniformly charged, and therefore, uniform development can be performed.

(Example) In the apparatus having the configuration shown in FIG. 1, the developer regulating roll member 5 was formed as a semiconductive member.

Specifically, a phenol resin in which carbon was dispersed and the resistivity was adjusted to 10'Ω·cIn was formed into a roll shape to form the regulating roll member 5. This roll member 5
The distance between the sample and the carrier l was set to 100 μm, and a DC voltage of 800 volts was applied between both members. When development was carried out under these conditions, no spark discharge occurred between the two members, and a developer layer with a uniform thickness was formed on the carrier surface la. was uniformly and sufficiently charged.

According to experiments conducted by the present inventor, a semiconductive member having a resistivity of 10 4 to 10 10 Ω·0 is suitable. Further, as shown in FIG. 2, even when the outer peripheral surface of the roll 17 made of a conductive material is coated with a semiconductive layer 19 made of a semiconductive material, the same effect as in the above embodiment can be obtained. did it.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the overall structure of the present invention, and FIG. 2 is a sectional view showing an example of the structure of a roll made of a semiconductive member. 1...Carrier 3...Developer 5...Regulation roll member 7...Voltage application means 1a, 5a...Surface patent application Fuji Xerox Co., Ltd. Figure 1 5a, 3a---# Image Figure 2

Claims (1)

[Claims] comprising a developer carrier, and a regulating roll member disposed at a predetermined distance from the carrier and regulating the layer thickness of the developer carried by the carrier to a predetermined thickness; In a developing device that applies a voltage between the carrier and the regulation roll member to charge the developer passing between the two members, at least one of the developer carrier and the regulation roll member is charged. A developing device characterized in that its surface is formed from a semiconductive member.