JPH01150180A - Developing device - Google Patents

Abstract

PURPOSE:To obtain an image with superior quality by preventing nonuniformity in density and the lowering of the density from being generated by providing a net shape member provided extending over entire width in the axial direction of a sleeve and a toner tank to replenish a toner in a developer bank. CONSTITUTION:A developing device is provided with the net shape member 6, the toner tank 12, and the developer bank 13. And at the time of developing an electrostatic latent image formed on a photosensitive material 1, the sleeve 10 is rotated in a direction of arrow head (a), and a magnetic roll 2 in a direction of arrow head (i), and a magnetic brush layer is formed by carrying a developer 7 in the direction of arrow head (a), and the electrostatic latent image is rubbed slidably and developed. At this time, even when the developer 7 is one-sided in the axial direction of the sleeve 10 by a mistake at the time of operating the developing device, a surplus developer 7 flows out in a direction of arrow head (e) from an aperture 11 provided at the upper part of the net shape member 6 only by rotating the sleeve 10 and the magnetic roll 2 for several times. The developer 7 that flows out is attracted by the magnetism of the magnetic roll 2, and is carried passing through the net shape member 6. In such a way, the quantity of the developer in the neighborhood of the sleeve 10 can be uniformized, thereby, the nonuniformity in the density or the lowering of the density can be prevented from being generated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a developing device for an electrophotographic copying machine, an electrostatic copying machine, etc., which visualizes an electrostatic latent image using a developer.

Conventional technology In recent years, the copy volume has been low, approximately 10 to 20 sheets/
In the case of copying machines of size (A4 size), the number of customer-installed or disposable units equipped with developing devices is increasing. High quality is also required.

An example of the conventional developing device described above will be described below with reference to the drawings.

FIG. 3 is a sectional view showing an example of a conventional developing device.

In the figure, 1 is a photoreceptor, 2 is a magnet roll, 3 is a developing housing, 4 is a blade, 6 is a partition plate, 6 is a net member, 7 is a developer, 8 is a toner, 9 is a blade, and 10 is a sleeve. be.

The operation of the conventional developing device configured as described above will be briefly described.

The sleeve 10 is made of a conductive non-magnetic material and has N inside it.
, Sli can be rotated independently of the magnet roll 2 which alternately magnetizes the magnets. When developing the electrostatic latent image formed on the photoreceptor 1, as shown in the figure, the sleeve 10 rotates in the direction of arrow a, the magnet roll 2 rotates in the direction of arrow s, and the developer 7 is rotated in the direction of arrow a. A magnetic brush layer is formed by transporting in the direction of , and the electrostatic latent image is rubbed and developed. The blade 4 is disposed on the upstream side in the direction of conveyance of the developer 7, facing the surface of the sleeve 10, and is precisely set to regulate the height of the magnetic brush. The partition plate 5 has an opening 5A through which the toner 8 is conveyed by the blades 9, and has a rectangular opening in the axial direction of the sleeve so that an appropriate amount of the toner 8 can be conveyed. The net-like member 6 is disposed parallel to the axial direction of the sleeve 1o, and is formed by molding, punching, or etching a woven material of fiber or wire made of a non-magnetic metal material, a magnetic metal material, an organic polymer material. It is formed by The mesh diameter of the net-like member 6 is 150 μm or more, that is, 100 mesh or less and 9.2 mesh or more, in order to allow the carrier to pass through and maintain the pressure of the developer 7.
The porosity is 30 to 70%.

The problem that the invention aims to solve However, in the above configuration, the toner.

If the developer is pre-filled and installed by the customer, the customer may not have followed the installation procedure and the developer may not be sufficiently stirred, or the developer may not be properly stirred depending on the transportation conditions. The magnet row) V is offset in the axial direction, and the amount of developer on the sleeve is extremely uneven, which causes problems with density unevenness and density reduction, especially in terms of initial image quality. Ta.

In other words, when the developer is shifted to one side as shown in FIG. 4, a large amount of developer 7 adheres to the sleeve 1o near the arrow C, but the amount of toner 8 is blocked by the developer 7 and is significantly reduced.
On the other hand, since only a small amount of the developer 7 is attached to the sleeve 1o near the arrow d, a large amount of the toner 8 is attached without being obstructed. Therefore, the initial quality tends to be light near C and dark near d on the image. Further, unless the developer 7 near C is reduced to a level where the toner 8 can pass through, the toner 8 will not be supplied until several tens to several hundreds of copies have been made, resulting in a decrease in density.

In view of the above-mentioned problems, the present invention provides a developing device that can inexpensively and easily prevent initial density unevenness and decrease in density and produce good images.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a rotatable sleeve having a magnet roll therein, a developer reservoir for supplying developer to the sleeve, and a developer reservoir for supplying developer to the sleeve. and a toner tank for replenishing toner to the developer reservoir, and a plurality of openings larger than the mesh openings are arranged in the axial direction of the sleeve at the upper part of the mesh member. It has the following configuration.

Operation According to the above-described structure of the present invention, even if the developer is distributed unevenly due to the plurality of openings in the net-like member, the excess falls off, so that the amount of the developer is made uniform in the axial direction of the sleeve. Further, for this reason, the amount of developer and toner adhering to the sleeve is also made uniform.

Furthermore, since the problem that the toner is difficult to transport due to interference with the developer is eliminated, the problems of density unevenness and density reduction are significantly improved, and good images can be obtained.

EXAMPLE Hereinafter, a developing device according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is an enlarged view of essential parts of a developing device in a first embodiment of the present invention. FIG. 2 is a front view showing the opening of the mesh member in the embodiment of the present invention. Note that the same components as those in the conventional example shown in FIG. 3 are given the same reference numerals. In FIG. 1, 6 is a net-like member, 7 is a developer, 8 is a toner, and 10
11 is a sleeve, 11 is an opening, 12 is a toner tank, and 13 is a developer reservoir.

The operation of the developing device configured as described above will be described below with reference to FIGS. 1 and 2.

In the figure, when developing the electrostatic latent image formed on the photoreceptor 1, the sleeve 10 rotates in the direction of arrow a, the magnet roll 2 rotates in the direction of arrow a, and the developer 7 is conveyed in the direction of arrow a. Then, a magnetic brush layer is formed, and the electrostatic latent image is rubbed and developed. At this time, even if the developer 7 is offset in the axial direction of the sleeve 1o due to an installation error by the customer or an error during operation of the developing device, the excess developer 7 can be removed by simply rotating the sleeve 10 and the magnet roll 2 several times. , from the developer reservoir 13 to the mesh member 6
Due to the pressing force of the developer 7 sent through the sleeve 1o, the developer 7 flows out in the direction of the arrow e from the opening 11 provided at the upper part of the mesh member 6 provided over the entire width of the sleeve 1o in the axial direction.

The developer 7 that has flowed out is attracted by the magnetism of the magnet roll 2 and is conveyed through the net-like member 6. As a result, the amount of developer 7 near the sleeve 1o is made uniform over the entire axial direction. Furthermore, the toner 8 is no longer blocked by the excess amount of the developer 7 and is not conveyed. For these reasons, the amounts of the developer 7 and toner 8 on the sleeve 10 are made uniform and stabilized, and there is no problem with toner transportation, so density reduction and density unevenness are eliminated, and good images can be obtained. .

As described above, according to the present invention, by providing the mesh member 6 with the openings 11 that are larger than the mesh, even if the developer is skewed due to a customer's installation mistake, mistake in transporting the developing device, etc., the openings 11
Since the developer flows out from step 1, the amount of developer and toner becomes uniform, resulting in uneven density.

Good images with no decrease in density can be obtained.

In the first embodiment, the openings 11 were formed in a single circular row as shown in FIG. 2A, but they may be staggered as shown in FIG. , may be rectangular as shown in FIG.

Effects of the Invention As described above, in the present invention, by providing the net-like member with openings that are smaller than the mesh, excess developer flows out through the openings to equalize the amount of toner and developer, thereby preventing density unevenness and density reduction. It is possible to prevent this and obtain good images.

[Brief explanation of the drawing]

FIG. 1 is an enlarged view of essential parts of a developing device according to a first embodiment of the present invention, FIG. FIG. 4 is a cross-sectional view of the developing device shown in FIG. 2... Magnet roll, 6... Net member, 7
...Developer, 8...Toner, 1o...
...Sleeve, 11...Opening. Name of agent: Patent attorney Toshio Nakao and 1 other person2-
11 Sagara Stone Roll 2 - 7 in the running height 1 person fortune telling and sai - Chisenjo Aiyoshi I / f - Isshoguchi 2nd figure! - Trillion light body 2 - Neishi row 2 3 - -Visual image 1 4... - Blade 5 - I±tη Hontan B - Toner Figure 4

Claims (3)

[Claims] (1) A sleeve that is rotatable and has a magnet roll inside, a developer reservoir that supplies developer to the sleeve, a net-like member provided over the entire width of the sleeve in the axial direction, and a toner reservoir that supplies toner to the developer reservoir. 1. A developing device comprising: a toner tank for replenishment, and a plurality of openings larger than the mesh openings are disposed in the upper part of the mesh member in the axial direction of the sleeve. (2) The developing device according to claim 1, wherein the openings are arranged in a staggered manner. (3) The developing device according to claim 1, wherein the opening is arranged in the shape of a long hole.