JPS61173272A - Developing device - Google Patents

Abstract

PURPOSE:To form a developing agent layer in which a developing agent grain passes through while it oscillates between both members, and the grain density is equal by impressing the alternating voltage between a holding body and a regulated roll member. CONSTITUTION:A regulated roll member 5 rotates at the speed in which a relative speed for a holding body 1 occurs, and a developing agent layer on a surface 1a of the holding body 1 is adjusted to an equal thickness by the regulated roll member 5. Further, between both members 1 and 5, an alternating voltage is impressed by a voltage impressing means 7. Consequently, the grain of respective developing agents to form the developing agent layer oscillates between both members 1 and 5 in accordance with the change of the polarity between both members 1 and 5. By the oscillation, the grain in a condensed condition is separated and stirred, and the developing agent layer with the equal density of the developing agent grain is formed.

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) In the past, as disclosed in JP-A-47-13088 and JP-A-53-167341, a developer is sent to a holder using a carrier, Non-magnetic component developing devices are known that develop electrostatic latent images into visible images. In such an apparatus, in order to regulate the layer thickness of the developer carried by the carrier to a predetermined thickness,
There is a system in which a regulating roll member is disposed in contact with the surface of a carrier, and a voltage is applied between the carrier and the regulating roll member to charge the developer that has passed between them.

(Problems to be Solved by the Invention) However, in the case where the regulating roll member is brought into contact with the surface of the carrier, the pressure contact force between both members must be carefully adjusted, and the pressure contact force causes both There is a risk that the members may be deformed and, on the other hand, both members may wear out due to long-term use, making it impossible to obtain a uniform developer layer.

(Means for Solving the Problems) For this purpose, the present invention provides a developing device that develops an electrostatic latent image using a developer 3 carried by a developer carrier 1, as shown in FIG. , a regulation roll member 5 disposed at a predetermined interval with respect to the developer carrier 1 and regulating the layer thickness of the developer 3 carried by the developer carrier 1 to a predetermined thickness; It is characterized by having a voltage applying means 7 for applying an alternating voltage between the developer carrier 1 and the regulating roll member 5.

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

When the carrier 1 rotates in the direction of the arrow, the layer of developer 3 carried on its surface 1a is conveyed toward the regulation roll member 5. This regulating roll member 5 rotates at a speed that generates a relative speed with respect to the carrier 1, and the developer layer on the surface la of the carrier 1 is adjusted to have a uniform thickness by this regulating roll member 5. Ru. Furthermore, both these members 1
．． 5, an alternating voltage is applied by voltage applying means 7. Therefore, the particles of each developer forming the developer layer vibrate between the two members 1.5 in accordance with the change in polarity between the two members 1.5. This vibration separates and stirs the aggregated particles, forming a developer layer with uniform developer particle density. In the figure, numeral 25 is a DC bias power supply for imparting charging polarity to the developer particles.

Next, as the carrier 1 continues to rotate, the developer layer 3a reaches a portion 13 adjacent to the electrostatic latent image holder 11.

The holding body 11 is rotating in the direction of the arrow, and its surface 11
An electrostatic latent image 15 is held in a. Therefore, in this proximal portion 13, the developer layer is formed on the holder surface 11 a I
=, adheres to the electrostatic latent image 15 of , thereby causing the latent image 15
is visualized. As described above, since the developer layer 3a is Y-charged and has a uniform thickness, the latent image 15 is developed evenly and uniformly.

The alternating voltage may have any waveform, such as a triangular wave, a rectangular wave, or a high frequency superimposed on a low frequency, and its frequency may range from 30011z to 2.5K1.
Preferably, it is within the range of 1z. That is, in the developer particles commonly used, even if an alternating voltage with a frequency of less than 300 Hz is applied, the vibration speed of the developer particles is slow, so that the particles are not sufficiently agitated. On the other hand, 2.
When using an alternating voltage with a frequency exceeding 5 KHz, the movement of the particles cannot follow the change in polarity, and the developer particles tend not to vibrate.

(Effects of the Invention) As described above, in the present invention, since an alternating voltage is applied between the carrier and the regulation roll member, the developer particles passing between the two members vibrate between the two members. Therefore, a developer layer with uniform particle density is formed.

(Example) In the apparatus having the configuration shown in FIG. 1, a roller made of a semiconductive material with a resistivity of 106 Ω·cm is used as the regulating roll member 5, and the distance between this member 5 and the carrier 1 is 50 μm.
Then, these two members are rotated in opposite directions at the same speed of 500118/sec, and further, Vr-r −8 is applied between both members.
A DC bias voltage of 200 V superimposed on an alternating voltage of 00 V, f = 1.5 Kllz was applied. When development was carried out under such conditions, the carrier surface 1a
A sufficiently charged developer layer 3a having a uniform layer thickness was formed. This developer layer 3a is obtained by stacking about three layers of developer particles in the thickness direction, and the amount of charge is 10 to 20 μc/g, which is approximately the same amount as the conventional one. It was done.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the overall configuration of the present invention. 1...Carrier 3...Developer 5.
... Regulation roll members 5a, 3a ... Surface 7 ... Voltage application means

Claims (1)

[Claims] In a developing device that develops an electrostatic latent image using a developer carried by a developer carrier, the developer is disposed at a predetermined distance from the developer carrier, and is carried by the developer carrier. What is claimed is: 1. A developing device comprising: a regulating roll member for regulating the layer thickness of the developer to a predetermined thickness; and voltage applying means for applying an alternating voltage between the developer carrier and the regulating roll member.