JPS6227773A - Developing device for one-component developer - Google Patents

Abstract

PURPOSE:To supply always a fresh developer and to make fatigue of a developer difficult to obtain stable image density for a long time by providing a developer peeling member which is in contact with a developer supply member to peel the developer remaining on the developer supply member. CONSTITUTION:A developer peeling member 8 is formed with a blade-shaped elastic body and is provided in a hopper 9 so that its one end is brought into contact with the peripheral surface of a developer supply member 2 in the rotation axial direction of the developer supply member. The developer which is not supplied to a developer carrier 1 to remain on the developer supply member 2 or passes a developing area once while being carried on the developer carrier 1 and is not transferred to an electrostatic latent image holding body 6 to return to the developer supply member 2 is peeled by the developer peeling member 8 in the hopper 9, and the fresh developer is supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a developing device, and in particular, to a developing device, in which a one-component developer supplied onto a developer carrier is formed into a developer layer of a predetermined thickness by a regulating member, and this developer layer is The present invention relates to a one-component developing device that electrostatically adsorbs a latent image onto an electrostatic latent image and develops it into a visible image.

Conventional technology A developing device for developing an electrostatic latent image formed on an electrostatic latent image holder has conventionally used a two-component developer consisting of toner and a carrier, which is charged by frictional charging with the carrier. Two-component developing devices that electrostatically attract toner to an electrostatic latent image have been actively developed and put into practical use. Two-component developing devices are reasonably practical, but in order to make the developing device itself more compact and easier to maintain, one-component developing methods and devices using a one-component developer consisting only of toner have been proposed. Among them, a one-component development method using a non-magnetic toner is desired from the viewpoint of high transparency of the toner in response to colorization.

Conventionally, as a non-magnetic component development method, U.S. Pat.
The touchdown development method disclosed in No. 95,847 is generally well known, and in this development method, a corotron discharge is used as a means for imparting an electric charge to the developer.

Although this method is simple, it has many drawbacks, such as the equipment being cumbersome and the need to periodically clean the cone wire on the roller. In order to improve this problem, we first proposed a non-magnetic component developing device in which a thin layer of developer is formed on the developer carrier by a regulating member that presses against the developer carrier, and a charge of a desired polarity is applied to the developer. did.

In this one-component developing device, the developer is sequentially supplied from the developer supply member to the developer carrier between the developer supply member and the developer carrier, which are in pressure contact with each other while rotating. The developer supplied to the developer carrier is formed into a uniform layer by an appropriate regulating member, and at the same time is triboelectrically charged, and is transferred to an electrostatic latent image carrier rotating close to the developer carrier. The electrostatic latent image is visualized by electrostatic adsorption.

Problems to be Solved by the Invention However, in a copying machine incorporating a single-component developing device configured as described above, there is a problem in that as the number of copies is increased, the image density of the copy may decrease rapidly. there were. Specifically, in the development region where the developer carrier and the electrostatic latent image holder face each other, a hanging DJ developer corresponding to the charge of the electrostatic latent image is transferred from the developer carrier to the electrostatic latent image carrier. In this case, the developer corresponding to the white part of the document remains on the developer carrier, and from the next cycle onwards, the developer is transferred to the developer supplying member or the regulating member. As the electrostatic latent image is repeatedly passed through the pressure contact portion, it may be physically fatigued, and the transferability of the electrostatic latent image to the electrostatic latent image holder in the development area may deteriorate. Further, at the contact portion between the developer carrying member and the developer supplying member, the developer is supplied from the developer supplying member to the developer carrying member, and at the same time, the developer is transferred in the opposite direction. That is, since the developer is replaced, the residual developer on the developer carrier described above also remains on the developer supply member and deteriorates in the same manner.

The present invention was made in view of such problems,
The purpose is to provide a one-component developing device that does not cause rapid deterioration of image S degree even after long-term use and can always provide stable copy density.

Means for Solving the Problems In order to solve the above-mentioned problems of the prior art, the present invention has the following features:
A developer supplying member and a developer carrying member are provided which are in pressure contact with each other while rotating, and a one-component developer is supplied from the developer supplying member to the developer carrying member, and further provided adjacent to the developer carrying member. J3 is in a one-component developing device that is sent to the electrostatic latent image holder and develops the electrostatic latent image, and contacts the developer supplying member to remove the developer attached to the developer supplying member. A one-component developing device is provided which is provided with a developer stripping member.

According to a preferred aspect of the present invention, the developer stripping member may be a blade-shaped member provided so as to come into contact with a developer supplying member within a hopper that accommodates the developer. According to another preferred embodiment of the present invention, the same member is rotated within the hopper.
A brush-like member provided so as to come into contact with the developer supply member can be used.

Operation An electrostatic latent image is formed on the electrostatic latent image carrier, for example, as follows. First, the surface of the electrostatic latent image carrier, which has been freed from the previous history, is uniformly charged.

Next, light corresponding to the original is imaged on the surface to eliminate the electric charge in the area irradiated with light, thereby forming an electrostatic latent image corresponding to the original. When the electrostatic latent image on the electrostatic latent image carrier comes to the development area, the developer moves from the developer carrier to the electrostatic latent image carrier, and electrostatically appears on the part where the charge has not disappeared. It adheres to form a developed image. The developer consumed during development is
The developer is sequentially supplied to the developer carrier from the developer supply member.

In the developing device of the present invention, since the developer stripping member is installed in contact with the developer supply member, the developer can be replaced with new developer in the popper without remaining on the developer supply member. Ru. As a result, new developer is always supplied to the developer carrier, and developer that has not participated in development is quickly replaced with new developer.

Practical Example Hereinafter, a preferred example of the present invention will be described based on the drawings (
I will explain it in detail.

FIG. 1 shows a typical example of a one-component developing device to which the present invention is applied. A developer carrying member 1 and a developer supplying member 2 are rotatably supported in a lower portion of a hopper 9 containing a developer 3 so as to rotate while being pressed against each other. A developer 3 is supplied to the developer supply member 2 from a hopper 9 . A portion of the developer 3 on the developer supply member 2 remains on the developer supply member 2 at the pressure contact portion between the developer carrier 1 and the developer supply member 2, and a portion remains on the developer carrier 1. A regulating portion 04 is supplied and moves while being held on the surface of the developer carrier 1 as the developer carrier 1 rotates, and is provided such that one end is fixed to the lower part of the hopper 9 and the other end is in pressure contact with the developer carrier 1. The electrostatic latent image 5 is formed into a thin layer and triboelectrically charged.
The latent image is moved to the vicinity of the electrostatic latent image holder 6 holding the latent image, and the latent image is visualized. Reference numeral 7 denotes a bias 'Fji source applied between the developer carrier 1 and the developer supply member 2 and the electrostatic latent image carrier 6 in order to improve development efficiency; It is electrically grounded to a frame (not shown) or the like.

Reference numeral 8 designates a developer stripping member that is characteristic of the present invention, and is formed from a blade-shaped elastic body, one end of which is connected to the developer supply member 2.
The hopper 9 is provided in the hopper 9 so as to be in contact with the circumferential surface of the developer supply member in the direction of the rotation axis of the developer supply member. The developer may not be supplied to the developer carrier 1 and remain on the developer supply member 2, or may not be transferred to the electrostatic latent image carrier 6 after passing through the development area while being carried by the developer carrier 1. The developer that has returned to the developer supply member 2 is stripped off within the hopper 9 by the developer stripping member 8 described above, and new developer is supplied.

Development was carried out under the following conditions using a one-component developing device having the above configuration. As the developer carrier 1, a cylindrical SUS member having 13 layers in diameter and covered with a phenol resin having a specific resistance of 106 Ωα is used, and this is made of an SUS leaf spring material having a thickness of 0.11iII+. The rule u1 member 4 was pressed with a pressure in the range of 50 to 5009/ls. As the developer supply member 2, an S with a diameter of 6H is used.
A US-made 100-cylindrical member with a thickness of 2 mm and coated with a rubber layer having a specific resistance of 103 Ωα was used, and this was attached to the developer carrier 1.
Il! I made him wear it. The electrostatic latent image holder 6 has a diameter of 60 mm.
A selenium-based photoreceptor was steamed on the surface of a cylindrical member (m), and the gap with the developer carrier 1 was set to 150 μm. As developer 3, a developer with an average particle size of 10 μm obtained by dispersing carbon black in a styrene acrylic resin was used.

Then, the electrostatic latent image holder 6 is rotated at a circumferential speed of 85 M/sec,
Developer carrier 1 and developer supply member 2 are 500V (7)
DC type 1f Ni800VIllFl, 300 Hz (D
It was rotated at a circumferential speed of 127.5 mm/sec while applying a superimposed alternating voltage as seven bias voltages.

Next, a general electrophotographic copying machine was constructed using this developing device, and repeated copying tests were conducted to examine the deterioration of the image 'cJ melon. FIG. 3 is a graph showing how the image density of a black portion changes over time in cases where the developer stripping member 8 described above is provided and cases where it is not provided. As is clear from the figure, in the conventional developing device that does not have a developer stripping member, the image density sharply decreases after about 10,000 cycles. In the developing device of the present invention provided and configured, 500
It can be seen that a stable image density was obtained up to 00 times.

FIG. 2 is a partial cross-sectional schematic diagram of a one-component developing device showing another preferred embodiment of the present invention. The reference numerals are given and the explanation thereof is omitted. In this embodiment, a brush-like developer stripping member 8' is provided instead of the blade-shaped developer stripping member. The developer stripping member 8' is composed of a shaft member 81 that is supported in parallel with the rotating shaft of the developer supply member 2 within the hopper, and a flocked hair 82 that is planted on the shaft member. One end of the developer supply member 2
It is rotated while in contact with the Is flocking 82 a developer using frictional charging? R8! In order to avoid this, it is preferable that the capacitor be made of a conductive material such as metal. A copying test similar to that in the first experiment was carried out using the developing device having the above-mentioned configuration, and the change in image m degree with respect to the number of copies was investigated, and the same results as in the first example were obtained. Obtained.

Effects of the Invention In the one-component developing device of the present invention, a developer stripping member that comes into contact with the developer supplying member is provided to strip off the residual developer on the developer supplying member. The developer is supplied, the developer is less likely to fatigue on the developer supply member, and stable image density can be obtained over a long period of time.

Although the present invention has been described mainly in relation to a developing device used in a copying machine, its use is not limited to copying machines, and can of course be applied to recording devices such as printers. be.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional schematic diagram of a one-component developing device showing a preferred embodiment of the present invention. FIG. 2 is a partial cross-sectional diagram of a one-component developing device showing another preferred embodiment of the present invention. The schematic configuration diagram, FIG. 3, is a graph showing changes in image density with respect to the number of copies. 1...Developer carrier, 2...Developer supply member, 3
...Developer (toner), 4...Regulation member, 5...
- Electrostatic latent image, 6... Electrostatic latent image holder, 7... Bias power supply, 8.8'... Developer peeling member, 9... Hopper.

Claims (1)

[Claims] A developer supplying member and a developer carrying member are provided which are in pressure contact with each other while rotating, and a one-component developer is supplied from the developer supplying member to the developer carrying member, and further provided adjacent to the developer carrying member. In a one-component developing device that develops the electrostatic latent image by being sent to the electrostatic latent image holder, the developer comes into contact with the developer supply member and peels off the developer attached to the developer supply member. A one-component developing device characterized by being provided with a developer stripping member.