JPS602967A - Developing device of electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To obtain a fog-free sharp copy even after long-period use by specifying a developer on the surface of a developing roll to a specific thickness with a roll type regulating member which has an elastic layer. CONSTITUTION:The roll type regulating member 6 is provided over the developing roll 4 rotatably while pressed. The member 6 consists of a metallic core 6a and the elastic layer 6b. The layer 6b is made of a foamed body of conductive urethane rubber having about 30 deg. hardness, and its specific resistance is 10<5>- 10<10>OMEGA.cm. A bias is inpressed from a bias power source 7 to the member 6, which rotates as shown by an arrow to regulate the developer sticking to the surface of the roll 4 to uniform thickness by the press-contacting force of the member 6 and relative speed difference, and the specific-thickness developer reaches a photosensitive body 1 to develop a latent image 8. In this case, the elastic layer 6b of the member 6 may be made of a hollow member.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a developing device 3 for an electronic copying machine using an Iri+ component non-magnetic developer.

PRIOR ART The cascade development method and the magnetic brush development method are widely used as the development methods for conventional electronic copying, but since they all use a second-order developer, they suffer from the same problems as the first-order developer. be. In other words, when using a secondary developer, the surface of the carrier becomes contaminated with the toner composition and the chargeability of the carrier is impaired during long-term use. In addition to the need to change the mixing ratio, the photoreceptor is damaged by the carrier, so it is necessary to periodically replace the developer, making maintenance cumbersome. In order to improve this problem, a developing method using a layer component magnetic developer using toner containing magnetic powder with relatively low resistance has recently been proposed, but this method may cause transfer defects at high humidity and may cause poor clarity. There are disadvantages such as the inability to obtain accurate color copies.

In order to improve these drawbacks, a developing method using an yl-adhesive agent using a non-magnetic toner having high resistance has also been proposed.

This developing method is performed as follows using, for example, the first developing device A developing roll C is provided, and a developing bias is applied to the developing roll CK at source d. Also hopper b
A one-component developer consisting of a non-magnetic toner is contained therein, and is carried to the photoreceptor α side as the developing roll C rotates.

A static latent image e formed on the surface of the photoreceptor α is developed. In such a developing device, in order to improve the retention of non-magnetic toner, the developing roll C is
Although unevenness is formed on the surface of the regulating member f, during long-term use, toner that has entered the four parts causes ghost images and edge effects, and the tip of the regulating member f is worn out due to the unevenness. However, there were drawbacks such as the inability to obtain the initial regulatory effect.

Purpose of the Invention The present invention is not intended to eliminate such drawbacks, but to provide a current electronic copying machine that can produce clear copies with almost no fogging even after long-term use. That is.

Structure of the Invention The regulating member for uniformly regulating the thickness of the one-component non-magnetic developer adhering to the surface of the developing roll is in the form of a roll having an elastic layer, and the unevenness on the surface of the developing roll is completely eliminated. Equipment B 10 Embodiments Below, an embodiment of this invention is shown below in Section 2 (9) □□□
The details will be explained with reference to the aspects. In the figure, reference numeral 1 denotes a photoreceptor of an electronic copying machine using an I-component non-magnetic developer, and a developing device main body 2 is installed near the photoreceptor 1. The main body 2 has a hopper 3 with an opening 3α opened on the side of the photoreceptor 1, and a one-component non-magnetic developer is accommodated in the hopper 3. , a part of the developing roll 4 protrudes from the opening 3α toward the photoconductor l (111).
is being accommodated. The development roll 4 has an uneven surface and is rotated in the direction of the arrow by a drive system (not shown), and a developing bias is applied by a bias power source 5.

Further, a roll-shaped regulating member 6 is provided above the developing roll 4.
is rotatably provided in a state in which it is in pressure contact with the existing roll 4. The regulating member 6 consists of a roll-shaped metal core 6α shown in FIG. 3 and an elastic layer 6b provided around the metal core 6α. The elastic layer 6b has a hardness of 300
- Made of tautromatic conductive urethane rubber foam, with a specific resistance in the range of 105 to 1010 Ωm. Note that when the resistance is less than IOsΩa, the capacity for large current to flow is
: ) Requires a large bias power supply and requires 1010ρ
If it is more than m, the current will flow and the charge cannot be sufficiently injected into the non-magnetic toner, so the above range is set.

On the other hand, the regulating member 6 has a metal core 6α and a bias power supply 7.
While a Taoden bias is applied, the developing roller 40 rotates in the direction of the arrow to regulate the developer attached to the surface of the developing roll 40 to have a uniform thickness by the pressure contact force of the regulating member 6 and the relative speed difference, and The fc developer is regulated to a constant thickness by the regulating member 6 and reaches the photoconductor IK, and then the FC developer reaches the photoconductor IK.
The electrostatic latent image 8 formed on the surface of the image is developed.

Further, the developer on the surface of the developing roll 4 that has been completely developed is scraped off by a scraping plate 9 provided in the hopper 3 and stored in the hopper 3, and the developer attached to the surface of the regulating member 60 is separated. The material is scraped into the hopper 3 by a scraping plate 10 .

Note that the regulating member 6 may be formed in the elastic layer 6b'r hollow as shown in FIG.

Effects of the Invention As described in detail above, the present invention has a regulating member 6 that regulates the developer adhering to the surface of the developing roll 3 to a constant thickness in the form of a roll having one elastic layer 6b. Since the developer is kept at a constant n by the pressure contact force and the relative speed difference, there is no need for unevenness or the like on the surface of the developing roll 3 to increase the developer holding power. As a result, even after long-term use, Q i<3! The depression is filled by the water,
As a result, there is no sagging that causes ghost images or edge effects, and it is possible to eliminate all problems such as the regulation f[tlJ member 6 being worn away by the developing roll 3 and not being able to obtain the initial regulation effect. Become.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional developing device piece, Fig. 2 is an explanatory diagram of a developing device showing an example of the present invention, and Fig. 3 is an explanatory diagram of a conventional developing device piece.
The oblique 'fM diagram of the member and FIG. 4 are sectional views showing other embodiments of the regulating member. 1 is a photoreceptor, 3 is a developing roll, and 6 is a parent 1u1] member. 6b is an elastic layer. Applicant: Fuji Xerox Co., Ltd. Agent: Tadashi Yonehara Patent attorney: Tadashi Hamamoto

Claims (1)

[Claims] In a device in which an electrostatic latent image formed on the surface of the photoreceptor 1 is developed on a developing roll 3 using a primary non-magnetic developer, the thickness of the developer attached to the surface of the developing roll 3 This developing device for an electronic copying machine is characterized in that a regulating member 6 for uniformly regulating the amount of water is formed in the shape of a roll having an elasticity of 1 m6bk.