JPH0430598Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a one-component developing device for a monochrome copying machine that allows color changes by replacing the developing unit.

Prior Art Recently, monochrome copying machines that can develop not only black but also chromatic colors such as blue, sepia, and green have been on the market.
The method for changing colors with this type of copier is as follows:
A common method is to develop an electrostatic latent image formed on a photoreceptor in a desired color by replacing developing units containing monocomponent developers of different colors and installing them in the main body. Since each developing unit to be replaced is provided with a developing roller for conveying the developer to the photoreceptor, the cost is high.

In addition, a sponge roller that is in pressure contact with the developing roller is used as a replenishment roller that supplies toner in the hopper of the replacement unit to the developing roller, but if the sponge roller is left in pressure contact for a long time, it will suffer from compression set. Toner is not replenished in that area, and white stripes appear on the copy.
Reduce image quality.

Purpose The present invention solves the above-mentioned drawbacks of the developing device of a copying machine, which allows color changes by replacing the conventional developing unit. The purpose is to provide a developing device.

Structure In order to achieve the above object, the present invention provides a developing roller for conveying developer to the photoreceptor on the main body of the copying machine and uses it in common for each replacement unit. A feature is that a replenishment roller for supplying toner is provided.

When a sponge roller is used as the replenishment roller, permanent deformation due to compression can be prevented by separating it from the developing roller when the power is turned off and bringing it into contact with the developing roller when the power is turned on.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. A developing roller 7 is provided in the main body of the copying machine in contact with the photoreceptor belt 16 . The replaceable developing unit 9 includes a sponge roller 5 that supplies the toner in the hopper 2 to the developing roller 7, a developing blade 14 that regulates the layer thickness of the toner on the developing roller 7 to be uniform, and a static eliminator that neutralizes the developing roller 7. brush 6
is provided. The developing unit 9 is supported so as to be swingable in angle at a fulcrum 1, and the developing unit side plate 3
Two positioning pins 12 and 13 implanted in the copying machine are positioned in two positions, an operating position and a rest position, by coming into contact with a stopper (not shown) provided on the main body of the copying machine. Switching between the two positions is performed by a solenoid (not shown) by turning on and off the power switch of the copying machine. The figure shows the state when the power is turned off, and the sponge roller 5 of the developing unit 9, the developing blade 14, and the neutralizing brush 6 are held at a position separated from the developing roller 7. Reference numeral 4 is an agitator for stirring the toner in the hopper 2. When the power is turned on, the developing unit 9 is rotated by a certain angle clockwise about the fulcrum 1 by a solenoid (not shown), and the positioning pins 12, 13 abut against stoppers (not shown) at the positions indicated by chain lines, and are positioned in the operating position. , the sponge roller 5, the developing blade 14, and the static elimination brush 6 are brought into pressure contact with the developing roller 7, and a state in which development is possible is achieved. Further, the copying machine main body is provided with a cleaning member 10 whose tip comes into contact with the developing roller 7 when activated by a switch to clean the developing sleeve. A container 11 for accommodating is provided.

When the developing unit 9 is set in the main body, the positioning pins 12 and 13 are in the position when the power is turned off. When the power switch is turned on, the solenoid moves the fulcrum 1.
It is rotated to the operating position and positioned. The developing unit 9 has a claw for color determination for each color of toner contained therein, and by setting the developing unit in the main body of the copying machine, color information is input to the CPU of the main body of the copying machine. The CPU of the copying machine has a non-volatile memory that contains previous information, which is compared with the color information of the currently installed developing unit. If they are the same, the cleaning device 10 will not operate, but
If this is not the case, the cleaning member 10 will come into contact with the developing roller 7, and the developing roller 7 will rotate for about 10 seconds, for example, and the toner will be scraped off and removed from the container 11.
will be collected. Needless to say, copying is prohibited during this time. When this is completed, the cleaning member 10 is retracted and copying becomes possible.

Effects According to the device of the present invention, there is no need to provide a developing roller in each replacement unit, which is effective in reducing costs. Also, since the sponge roller is separated from the developing roller when not in operation, the sponge roller will not be compressed for a long time, and uneven developer supply due to permanent distortion will not occur, and white stripes will not appear on copies. . As a result, the developing unit can be used until the blade reaches the end of its life, thereby extending its life.

[Brief explanation of the drawing]

The accompanying drawings are cross-sectional views showing the structure of an embodiment of the present invention. 5...Sponge roller for toner replenishment, 7...Developing roller, 9...Developing unit (replacement unit),
10... Cleaning member, 16... Photoreceptor belt.

Claims (1)

[Claims for Utility Model Registration] (1) In a developing device of a color changeable monochrome copying machine in which developing units containing one-component developers of different colors are used interchangeably, a developer is applied to a latent image carrier. A developing roller that conveys toner is provided on the copying machine main body side and is common to each replacement unit, and each replacement unit is provided with a sponge replenishment roller that supplies toner to the developing roller. A developing device that is separated from the roller and comes into contact with the developing roller when the power is turned on. (2) The developing device according to claim 1, wherein the developing roller can be cleaned by a cleaning member when changing colors.