JPS6143770A - developing device - Google Patents

Abstract

PURPOSE:To control the thickness of a toner to a proper value to prevent the variance of development by pressing a blade, which controls the thickness of the toner on a toner carrier from which the toner is supplied to a latent image carrier, to the toner carrier with a magnetic force. CONSTITUTION:The toner 2 in a tank 1 is agitated by an agitator 3 and is supplied to a sleeve 5 in the direction of an arrow A by a toner supply roll 4. The thickness of the toner 2 is controlled by a blade, which has one end supported on the tank 1 and consists of an elastic body, to supply the toner onto the sleeve 5. A magnet is provided in the side opposite to the face of the blade 6 brought into contact with the sleeve 5, and a core member 8 of the sleeve 5 is constituted with a magnetic material, and the blade 6 is pressed to the sleeve by the attraction of the magnetic force between them, and the toner is controlled thinly and uniformly and is supplied. Thus, the variance of development is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a developer carrier that supports Wi-transferred developer, and a layer thickness regulating member that regulates the layer thickness of the developer on the carrier. The present invention relates to a developing device that converts a latent image formed on a latent image carrier into a visible image by using a developer after regulating the thickness of one layer.

It has been well known to use the above type of developing device in image forming devices such as electronic copying machines and printers. In this case, when using a one-component developer that does not contain a carrier,
It is necessary to reduce the layer thickness of the developer on the developer carrier using a layer thickness regulating member and to make the thickness uniform. This is because if the layer thickness of the developer is too thick, it will be difficult to charge the developer uniformly, and there is a risk that the quality of the visible image after development will deteriorate. For this reason, various layer thickness regulating members designed to regulate the developer layer thickness have been proposed and put into practical use, but depending on the conventional regulating members, it is easy to thin the developer layer uniformly. It wasn't.

An object of the present invention is to provide a developing device that eliminates the above-mentioned conventional drawbacks.

The present invention proposes a configuration in which the layer thickness of the developer is regulated by pressing a single layer thickness regulating member against the developer carrier by at least magnetic force.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a case where the developing device according to the present invention is used in an electronic copying machine, in which a one-component developer is stored in a tank 1, and in this example, a non-magnetic-component developer 2 (hereinafter referred to as a non-magnetic component developer) is used. Toner (or simply referred to as toner) is stored therein. tank 1
The toner 2 inside is stirred by an agitator 3, and a toner supply roller 4 rotates counterclockwise.

In this example, one developer carrier rotates counterclockwise while contacting the roller 4, and is supplied to the cylindrical developing sleeve 5 (
Arrow A).

The toner supplied to the surface of the sleeve 5
As the sleeve rotates, it is carried while being supported on the sleeve surface,
The layer thickness regulating member 6 according to the present invention regulates the thickness to be thin and uniform, and details regarding the regulating member 6 will be explained later.

The toner on the sleeve 5 that has passed through the layer thickness regulating member 6 forms a single layer of toner whose thickness is regulated to be thin.

To remove insects, the toner is charged to a predetermined polarity, eg, positive, by friction with this member 6. Therefore, when this one layer of henna reaches the developing area C facing the latent image carrier, in this example the photoreceptor 7, traveling in the direction of the arrow B, the electrostatic latent image formed on the photoreceptor 7 is electrostatically charged. The latent image becomes a visible image.

As the developing sleeve 5, a sleeve having an appropriate structure can be used. For example, as schematically shown in FIG. A sleeve or the like formed by laminating electrode dispersion layers 11 can be used as appropriate. Each microelectrode IO is insulated from each other and also from the core member 8, and acts as a float ff1ll, but since its function is already known, its details will be omitted (for example, 57-114163), and when a microelectrode is used, there is a tendency for charge to accumulate in the electrode or the insulating material around it. It is best to remove static electricity.

Next, details of the layer thickness regulating member 6 will be explained.

The illustrated regulating member 6 is formed into a blade that contacts the sleeve 5 via a 1-ner, and a magnet 13 is fixed to the regulating member surface on the opposite side from the sleeve 5. The regulating member 6 is
The rear end is fixed, for example, to the tank 1, and the tip is pressed against the sleeve 5, thereby regulating the amount of toner passing between the regulating member 6 and the sleeve 5, and therefore the layer thickness thereof.

In this case, conventionally, the blade-shaped regulating member 6 was pressed against the sleeve 5 by simply pressing it elastically, but with this configuration, the effect of uniformly thinning the toner could not be obtained, and after passing the blade, There was a risk that the thickness of the toner layer would be uneven.

Therefore, in the configuration according to the present invention, the magnet 13 described above is provided, the core member 8 of the sleeve 5 is made of a magnetic material, the magnet 13 is attracted to the sleeve 5 side by magnetic force, and the regulating member 6 is pressed against the surface of the sleeve 5. let In this way, the regulating member 6 can be uniformly pressed against the surface of the sleeve 5 through the toner, and the layer thickness of the toner passing through the regulating member 6 can be made as thin as desired and the thickness can be made uniform. It is possible to do so.

If the toner layer is formed neatly and uniformly as described above, the toner will be Nrg due to friction with the regulating member 6.

The entire surface can be charged uniformly. The same applies when a corona discharger or the like other than a blade is used as the charging means.

F! Although the I-thickness regulating member 6 may be pressed against the sleeve 5 only by magnetic force, the regulating member 6 is made of an elastic body and is pressed against the sleeve 5, so that both the mechanical pressing force and the magnetic force are applied. Of course, the regulating member 6 may be pressed against the sleeve 5 in this manner.

In the embodiment shown in FIG. 1, a part of the sleeve 5 is made of a magnetic material, but when the entire sleeve is made of a non-magnetic material, as shown in FIG. The same result can be obtained even if the magnetic body 14 is fixedly arranged.

Moreover, instead of fixing the magnet 13 to the regulating member 6, if the layer thickness regulating member 6 itself is magnetized so that the regulating member has a layer thickness regulating function and a magnet function, a special magnet 13 as shown in the figure can be used.
is not necessary.

The same result can be obtained by using a magnetic material as the regulating member 6, or by fixing a magnetic material to the non-magnetic regulating member 6 and providing a magnet inside the sleeve 5. Furthermore, magnets with different polarities (including the case where the blade itself is magnetized) can be provided inside the sleeve and outside the sleeve. Further, as is known per se, a rotatable magnet may be provided inside the sleeve, or a magnet known as a rubber magnet or a plastic magnet may be provided integrally with the sleeve.

Above, we have explained the case where non-magnetic toner is used.9
It is clear that the present invention is applicable also when a magnetic component type developer (magnetic toner) is used, and members other than the blade can be used as the layer thickness regulating member, such as belts, metals, rollers, fur brushes, rubber rollers, and sponge rollers. The present invention is similarly applicable when using a developer carrier, etc., or when a bell 1- is used as a developer carrier.

According to the present invention, it is possible to uniformly regulate the layer thickness of the developer by a very simple structure in which the single layer thickness regulating member is pressed against the developer carrier by magnetic force. Ta.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a developing device to which the present invention is applied. FIG. 2 is a partial cross-sectional view showing another embodiment. 2...Developer 6... Layer thickness regulating member

Claims (1)

[Scope of Claims] A developer carrier carrying a one-component developer to be transported;
A developing device that includes a layer thickness regulating member that regulates the layer thickness of the developer on the carrier and visualizes a latent image formed on the latent image carrier by the developer after regulating the layer thickness, The developing device is characterized in that the layer thickness regulating member is pressed against the developer carrier by at least magnetic force.