JP2549059Y2 - Developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to development in electrophotography in which an electrostatic image formed on the surface of an image carrier is visualized by a triboelectric toner having insulating properties. More particularly, the present invention relates to a developing device configured to be able to smoothly and uniformly supply an initial developer formed by mixing a magnetic carrier and a toner onto a sleeve.

[Conventional technology]

In electrophotography, an electrostatic image is formed on the surface of a photoreceptor, and the electrostatic image is visualized by colored particles called toner.
After the transfer of the visualized toner image onto a transfer member, the toner image is fixed by thermal means or the like to obtain a hard copy. Various development methods in the electrophotographic method have been proposed so far, but a method in which a two-component developer which is a mixed powder of a non-magnetic toner and a magnetic carrier is used as a developer by a magnetic brush method, or only a magnetic toner is used. The method of using the method is mainly used. Conventionally, when these powder developers are used, a sleeve made of a non-magnetic material and a permanent magnet member disposed in the sleeve are relatively rotated to allow the developer adsorbed on the sleeve surface to be moved from the inside of the developing device to the developing area. To the developing device, and after the development is completed, the surplus developer is collected again in the developing device.

In recent years, it has also been proposed to use a mixture of a magnetic carrier and a magnetic toner as a developer as described in JP-A-59-162563, JP-A-59-216149 and JP-A-62-184474. It is said to share the advantages of the two-component system and the one-component system.

FIG. 2 is a cross-sectional view of a main part showing an example of a conventional developing device. In FIG. 2, reference numeral 1 denotes an agitation tank, which is formed so as to be able to store a magnetic toner 2 for replenishment, and a rotatable paddle 3 for supplying toner. 4 is a developer tank,
The bottom is communicated with the stirring tank 1 and formed so as to be able to accommodate a developer (not shown) formed by mixing a magnetic carrier and a magnetic toner. Next, reference numerals 5 and 6 denote sleeves and permanent magnet members, respectively, which are coaxially and rotatably provided at the lower end of the developer tank 4 and face the photosensitive drum 7. Reference numeral 8 denotes a doctor member, for example, a surface of the sleeve 5 and
Provide 0.2 to 1.0 mm apart. Reference numeral 9 denotes a cover, which is mounted via a set screw 10 so as to cover the upper part of the developer tank 4. A cover 11 is provided above the stirring tank 1 so as to be freely opened and closed. Reference numeral 12 denotes a toner level sensor provided near the bottom of the stirring tank 1.

With the above configuration, the developer (not shown) contained in the developer tank 4 is adsorbed on the sleeve 5 and the photosensitive drum 7
Is transported to a development area opposed to and performs a predetermined development. The magnetic toner 2 in the stirring tank 1 is successively supplied into the developer tank 4 by the paddle 3. When the amount of the magnetic toner 2 decreases to a predetermined amount or less, a signal of the toner level sensor 12 is issued. Therefore, the cover 11 is opened as shown by a broken line, and the magnetic toner 2 is supplied by a bottle 13 shown by a broken line.

[Problems to be solved by the invention]

In the developing device having the above-described configuration, when supplying the initial developer, the cover 11 is opened as shown by a broken line, and the magnetic developer and the magnetic toner are mixed in advance, and the initial developer is adjusted to a predetermined toner concentration. For example, stirring tank 1 via bottle 13
Supply within. Next, the entire developing device is rotated slightly counterclockwise or the paddle 3 is manually rotated clockwise to move the initial developer (not shown) into the developer tank 4. .

However, when the above-described method of supplying the initial developer is adopted, there is a problem that the initial developer is not smoothly and uniformly supplied into the developer tank 4, and that a long time is required for the supply. Further, as a result, the initial developer is not uniformly adsorbed and conveyed onto the sleeve, resulting in problems such as the occurrence of shading unevenness in the image and the development failure. Even if the cover 9 above the developer tank 4 is opened to supply the initial developer directly into the developer tank 4, this portion is generally narrow because other components are arranged close to each other. At the same time, since the cover 9 is not originally designed to be easily opened, there is a problem that it is practically impossible to directly supply the initial developer.

The present invention solves the above-mentioned problems in the prior art, and provides a developing device capable of smoothly and uniformly supplying an initial developer containing a mixture of a magnetic carrier and a toner onto a developer tank and a sleeve. With the goal.

[Means for solving the problem]

In order to achieve the above object, the present invention comprises a hollow cylindrical sleeve made of a non-magnetic material and a plurality of magnetic poles provided coaxially inside the sleeve and extending in the axial direction on the outer periphery. A developing device comprising: a permanent magnet member; a developer tank that stores the developer and holds the sleeve and the permanent magnet member; and the developer is transported to the developing area by the sleeve to perform development. A stirring tank for containing the toner is provided adjacent to the developer tank for containing the developer composed of the toner and the magnetic carrier, and the developer tank and the stirring tank are configured to communicate with each other and provided above the sleeve. The developer tank is provided with an opening having a length corresponding to the length of the sleeve, and a rotatable cover covering the opening. The initial developer comprising toner and a magnetic carrier is provided. A technical means is adopted in which the power is supplied to a range where the magnetic attraction force of the permanent magnet member acts through the opening.

[Action]

With the above configuration, the initial developer can be easily and smoothly supplied into the developer tank, and the initial developer is supplied within a range where the magnetic attraction force of the permanent magnet member acts. Immediately upon the rotation of the member and / or the sleeve, a stirring action is performed, and the material is uniformly adsorbed on the surface of the sleeve.

〔Example〕

FIG. 1 is a cross-sectional view of an essential part showing an embodiment of the present invention.
The same parts are indicated by the same reference numerals as in FIG. In FIG. 1, reference numeral 14 denotes an opening, and a length corresponding to the length dimension of the sleeve 5 is provided in the developer tank 4 above the sleeve 5, preferably in the vicinity of a vertical plane in contact with the outer periphery of the sleeve 5 on the stirring tank 1 side. Form to dimensions. A cover 15 is rotatably provided via a support member 16 and a pin 17 so as to cover the opening. Other configurations are the same as those shown in FIG.

With the above configuration, when supplying the initial developer,
The cover 15 is rotated clockwise as indicated by a broken line to open the opening 14, and a bottle containing an initial developer prepared by mixing a magnetic carrier and a magnetic toner so that the toner concentration becomes a predetermined value in advance. 13 is turned over above the opening 14, and the initial developer 18 is supplied into the developer tank 4. In this case, it is desirable to perform the supply operation while moving the bottle 13 in the longitudinal direction of the opening 14. As described above, the initial developer 18 is supplied within a range where the magnetic attraction force of the permanent magnet member 6 acts. Adsorbed uniformly. After supplying a predetermined amount of the initial developer 18, the cover 15 is rotated counterclockwise to close the opening 14, and the initial developer 18,
This prevents scattering of the developer formed thereafter and intrusion of dust, foreign matter, and the like. When supplying the initial developer 18, a magnetic carrier may be supplied in advance, and then a magnetic toner may be supplied.

In this embodiment, an example is described in which the initial developer is a mixed powder of a magnetic carrier and a magnetic toner. However, in the case of the initial developer which is a mixed powder of a magnetic carrier and a non-magnetic toner (or a weak magnetic toner), Of course it is applicable.

[Effect of the invention]

Since the present invention has the above-described configuration and operation, the initial developer can be easily, smoothly and uniformly supplied onto the developer tank and the sleeve, and the initial rise time of the developing device can be reduced. There is an effect that a high-quality image without shading can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a main part showing an example of a conventional developing device. 4: developer tank, 5; sleeve, 6: permanent magnet member, 14: opening, 15: cover.

Claims (1)

(57) [Scope of request for utility model registration] 1. A sleeve formed in a hollow cylindrical shape from a non-magnetic material, a permanent magnet member provided coaxially in the sleeve and provided with a plurality of magnetic poles extending in an axial direction on an outer periphery, and a developer. And a developer tank that holds the sleeve and a permanent magnet member, and is configured to transport the developer to a development area by the sleeve to perform development, comprising a toner and a magnetic carrier. A stirring tank for containing toner is provided adjacent to the developer tank for containing the developer, and the developer tank and the stirring tank are configured to communicate with each other. An opening having a length corresponding to the length is provided, and a rotatable cover is provided to cover the opening. An initial developer including toner and a magnetic carrier is supplied to the permanent magnet member through the opening. A developing device characterized in that the developing device is configured to supply the gas to a range where the air suction force acts.