JPS58174973A - Developing device - Google Patents

Abstract

PURPOSE:To make it unnecessary to control toner density by only replenishing a developer, and to obtain an image having a good quality without treating a form sheet, by rotating with a relative speed both rotating sleeve which is placed in a liquid developer and has a hole on the circumferential face, and photoreceptor. CONSTITUTION:In a conductive liquid developer 11, the lower part of a conductive rotating sleeve 12 provided with holes 12a on the circumferential face is immersed, is opposed to a photoreceptor 1 without contacting each other, and are rotated at a relative speed. When a latent image on the surface of the photoreceptor 1 gradually approaches the sleeve 12, the developer 11 held by surface tension to the holes 12a is subjected to electrostatic power, and also when the gap to the photoreceptor 1 becomes narrow, the electrostatic power becomes strong, the developer 11 jumps to the surface of the photoreceptor 1 as a droplet, and a visible image is formed on the surface of the photoreceptor. Accordingly, the developer is made to adhere to the photoreceptor by electrostatic power, therefore, it becomes unnecessary to control toner density, and the sleeve for holding the developer is rotated, therefore, this developing device can be applied to a high speed printing machine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device used in electrostatic recording.

Conventionally, developing methods used for this type of electrostatic recording can be broadly classified into dry developing methods and wet developing methods. Among the dry developing methods, there is a two-component developing method, in which a gearia and toner are mixed to form a developer, and the toner is charged to create a blank image. This is a method of developing using a K6i balance with the latent liquid. This method provides good image quality, is most commonly used in low-speed to high-speed copying machines, and is technically established. However, a toner concentration control mechanism is required to maintain a constant mixing ratio of toner and carrier, and the spent toner in gear 11a generated by mixing the toner and carrier causes the life of the developer to be shortened. It has drawbacks such as the need to regularly replace it.

- Since the component development method does not use a carrier, these toner concentration control mechanisms do not cause problems in terms of developer life, but the image quality is poor and the paper cannot be used unless it is treated with high resistance. This limits the number of papers that can be used to one per month. On the other hand, the wet development method has good image quality, but since it uses Isopar liquid, which is a petroleum-based solution, it requires careful handling, is difficult to print at high a degree, and is There is a problem where you have to decide which paper to use.

The present invention solves the above problems by eliminating the need for toner density jW control, and only replenishing the developer i++ regardless of the lifespan of the developer, using non-hazardous or non-polluting water-soluble or organic To provide a liquid type developer which uses a solvent developer to maintain an image quality comparable to that of gravure printing, and which enables printing without processing paper and which develops an electrostatic latent image. That is, in the present invention, a conductive developer is used as a developer, C is contained in the developer stored in a tank, and a conductive rotary sleeve having holes on its circumferential surface is rotatably disposed. The rotating shaft 1) and the photoreceptor are made to face each other without contacting each other, and are rotated at a relative speed.

Next, please refer to the drawings for an embodiment of the present invention (7).

In FIG. 1, when the surface of the photoreceptor 1 is charged with a charge 52 and the original 6 is exposed with exposure/step/, 4, a latent image of the original is formed on the one-hydrogen surface. The latent image moves the developing device 5 to j! At the same time, developer droplets fly onto the photoreceptor 1 and adhere to the latent image on the surface of the photoreceptor 1, forming a visible image. -)j, the paper is fed from the hopper 6 in a synchronized manner by the transfer unit 7 where the paper is transferred. Transfer device 7
The paper is charged and the visible image on the surface of the photoreceptor is transferred onto the paper, completing the transfer. Since the visible image on the surface of the photoreceptor is not entirely transferred, it is cleaned by the cleaning mechanism 8. The charge remaining on the surface of the photoreceptor is removed by the neutralizing light of the static eliminator 9, and the electrophotographic process is completed.

FIG. 2 is a sectional view of the developing device 5 according to the present investigation.

-1- That is, in the present invention, a conductive developer is used as a developer, and holes 12a are provided on the circumferential surface of the developer 11 stored in a tank 10. time l15
A tube 11--a tube 12 is partially immersed and arranged rotatably. Further, the rotating sleeve 12 and the photoreceptor 1 are made to face each other without contacting each other, and are rotated with a relative distance d8)↓.

FIG. 6 is a schematic diagram illustrating the principle of the invention. Photosensitivity 1□14
1 and sleeve 12 have relative speeds and rotate.

When the latent image on the surface of the photoreceptor 10 gradually approaches the sleeve 12, an electrostatic field is generated between it and the sleeve 12, and the surface of the hole 123ζ is held at the same potential as the sleeve 12 by the surface 5k, 7]. The developer 11 is subjected to electrostatic force. Furthermore, when the gap between the two becomes narrower as shown in FIG. 3(i)), the electrostatic force becomes even stronger, and the developer 11 becomes droplets and flies onto the surface of the photoreceptor, defying viscosity, surface tension, and gravity. A visible image is formed on the surface of the photoreceptor.

According to experiments, the circumferential speed of the photoreceptor 1 was set at 5 Cm to 100 Cm.
m/S, relative speed of sleeve 12 02-10
A good image was obtained when the magnification was set to 8 degrees, the gap with the photoreceptor 1 was set to 01 to 150, and the potential difference between the latent image on the photoreceptor and the sleeve was set to 100 or more. [・″・1, s11-
A bias voltage V is applied to the photoreceptor 7'! Even if the potential difference between the insert and the sleeve is maintained, the printing density can be varied by changing the bias voltage.
~75CpS, surface tension is 5-100 clines/c
m, the density doesn't really matter, about 1 g/-1,000 degrees, and the resistance value only needs to be conductive, about 1 ohm-c〃・or less j! It is fine as long as it is ↓. Also, either water-based or oil-based may be used. As the viscosity of the developing device 11 increases, the loading speed 1 becomes slower.
If the surface hydraulic force is small, it is difficult to obtain ψ, and if the surface hydraulic force is high, the potential difference between the photoreceptor and the sleeve becomes large. If the gap between the photoreceptor and the current rL plate is small, a liquid 1 layer will be formed on the photoreceptor, resulting in a trailing image, and if there is too much, the image will be disturbed. Hole 1 of sleeve 12
If the diameter of 2a is small (NjJl), a good image will be obtained, but this is true for brass, where the developing speed is slow. The size of the hole 12a is 000
It may have a diameter of 5 to 0.8 m, and its shape does not necessarily have to be circular, and may be porous.

As shown in FIG.
! 4 fm, and the developer is applied to the photoreceptor using electrostatic force, eliminating the need for toner concentration control and replenishing the developer, allowing for high-quality images without the need for processing. Furthermore, since the sleeve that holds the developer is rotated, it has the effect of reducing the cost of high-speed printing.

41ZI Figure 1 shows a simple situation of copying threat tλτ using the developing device according to the present invention.
Figures 2 and 2 are cross-sectional views of the current household appliances according to the present invention, and Figure 6 (
at, (bl is an abbreviation [-/1 indicating the principle of the present invention.

1...-t, & light body, 5... developer, 1o... current T solution, 11. tank, 12... sleeve, 12a hole in sleeve.

Patent applicant: NEC Corporation T1 Agent: Naka Kanno, patent attorney.

V Figure 1

Claims (1)

[Claims] (1) A developing device that develops an electrostatic latent image (17) uses a conductive developer as a developer, and a hole is provided on the circumference of the developer stored in a tank. A developing device characterized in that a rotating sleeve (31) is rotatably arranged, the rotating sleeve and a photoreceptor (tf) are brought into contact with each other, and the two are rotated at a relative speed (2).