JPS62102261A - Developing device for copying machine - Google Patents

Abstract

PURPOSE:To extremely easily execute the exchange of developers by arranging a unit having plural developing rollers of along a black toner developing unit and a color toner along a belt-like photosensitive body so that both units can be allowed to contact and separate with an from each other. CONSTITUTION:The 2nd developing unit 11 for black toner is arranged along the belt photoreceptor 1 so as to be moved in the right and left direction. A frame 12 is pivotally supported around a shaft 14 and the 1st developing unit 12 storing developing rollers 15a-15c for different color toners in it is arranged. Black toner development is usually executed, but when the unit 11 is moved in the right direction at the developing with color toners, an arm 26 is also moved to the right by a spring 29 and one of the developing rollers is allowed to contact with the arm 26 to execute prescribed color development. When a slider 34 arranged on the upper part of the unit 12 is moved, the frame body 12 is released and toner feed can be exchanged, so that the developers can be extremely easily exchanged.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device for a copying machine using a belt-like photoreceptor, and more particularly to a developing device for a copying machine that switches between a plurality of color developers to make monochrome copies.

2. Description of the Related Art Copying machines are known in which a plurality of developers are selectively used for a limb blood photosensitive drum.

Such conventional copying machines have had a problem in that changing the developer in the developing device is complicated. Furthermore, there was a risk of damaging the photoreceptor when changing the development.

SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device that facilitates switching between a plurality of developers and does not cause damage to a photoreceptor.

The present invention achieves the above object by using a belt-like photoreceptor as a photoreceptor for forming an electrostatic latent image, and having a plurality of developing units arranged along the running path of the belt-like photoreceptor, and one bottom. The developing unit has a plurality of developer chambers divided in the circumferential direction, a rotatable frame body and a developing roller rotatably supported at the opening of each developer chamber, and another developing unit This was achieved by a developing device for a copying machine characterized by having a developing roller that is movable toward and away from the belt-shaped photoreceptor.

The structure and operation of the present invention will be explained in detail with reference to embodiments shown in the drawings.

In FIG. 1, a polyester film is used as the base material. P
C-belt photoreceptor 1 is supported by rollers 2, 3.4,
Rotationally driven. Along the belt photoreceptor 1 are a charging charger 5, an exposure illumination device 6, a developing device 7, and a transfer charger 8.
, a static eliminator 9 is arranged.

The developing device 7 has a first developing unit 10 and a second developing unit 11 arranged adjacent to each other along the belt photoreceptor I.

The first developing unit 10 is rotatably supported by a frame 12.
The frame has a plurality of developer chambers in the circumferential direction by partition walls,
In the example shown, 3f1Ml developer chambers 13a13b, 13C
It is divided into. The frame body 12 is formed, for example, as a cylindrical body rotatably supported by a shaft 14. One developing roller 15a, 15b, 15 is installed in the opening formed on the outer periphery of the frame of each divided developer chamber 13a, 13b, 13C.
C is rotatably supported. Each developer chamber 13a, 13b
, 13C are provided with supply rollers 16a, 15b, 16c and stirring agitators 18a, 113b, 18c.

The developer replenished by the replenishment rollers 16a, 15b, and 16c is made into a uniform layer by the developer blades 17a, Fb, and 17c, respectively, and then the developer rollers 15a,
It is IM-transmitted to the belt photoreceptor 1 by 15b and 15c.

Developer chamber 13a.

Color toners of different colors are stored in 13b and 13c, respectively, and the frame body 12 is rotated so that the developing roller of the toner of the color to be developed comes into contact with the belt photoreceptor 1.

The second developer unit 11 is normally used to contain black toner and includes a casing 19 containing the toner, an agitator 20, 21, 22 arranged in the casing, and a developer roller 23 arranged at the casing outlet. has. The casing 19 includes a developing blade 24 and a static elimination brush 2.
5 is a provision.

An arm 26 is rotatably supported on the shaft 27 of the roller 4 that supports the belt photoreceptor 1, and a backup roll 28 is rotatably supported on the arm 26.

The arm 26 is biased by a spring 29 with a force that rotates the arm 26 clockwise in the figure, that is, in a direction that presses the back unroll 28 against the belt photoreceptor 1.

Normally, a protrusion 30 provided on the arm 26 comes into contact with a positioning ring 31 formed coaxially with the developing roller 23, and the back unroll 28 is held in a non-contact state with the belt photoreceptor 1. At this time, the belt photoreceptor 1 is in contact with the developing roller 23 of the second developing unit 11, but the corresponding developing roller of the first developing unit 10, in the figure, the developing roller 1
It does not touch 5a. Therefore, black toner development is performed on the belt photoreceptor l by the second developing unit 11.

As shown in FIG. 2, the entire second developing unit 11 including the casing 19 is movable to the left and right in the figure between a position where the developing roller 23 contacts the photosensitive belt weight and a position where it separates from the belt.

When the second developing unit 11 is moved to the non-operating position away from the belt photoreceptor 1 as shown in FIG. back up roller 28
pushes the belt photoreceptor 1 toward the corresponding developing roller 15a of the first developing unit 10, so that the belt photoreceptor 1 comes into contact with the developing roller 15a. At this time, the large-diameter rollers 32 provided at both ends of the backup roller 28 come into contact with the positioning portions 33 corresponding to each developer chamber of the frame 12, thereby positioning the developing roller 15a and the belt photoreceptor 1. It will be done.

In response to the movement of the casing 19 of the second developing unit 11, a clutch in a drive system (not shown) is operated to turn on and off the driving of the developing roller 23 of the second developing unit and the first one.
The developing roller (for example, 15a) facing the belt photoreceptor 1 of the developing unit 10 is switched between FF and ON.

The second developing unit 11 can also be modified so that only the developing roller 23 is moved instead of the whole including the casing 19.

If the frame 12 of the first developing unit 10 is constructed so that it can be easily deposited by moving the original slider 34 on the top of the copying machine body and releasing the top side of the frame 12, toner replenishment and unit replacement are easy. becomes easier. Also, initially only the second developing unit can be installed, and the first developing unit can be purchased and installed later as needed.

According to the present invention, frequently used toner is stored in the casing of the second developing unit which can store a large amount, and color toner which is used less frequently is stored in the frame of the first developing unit which can store small amounts of various types of toner. Can be housed separately.

Moreover, since multiple developing units are installed separately, toner replacement operations are much easier.

Copying machines became cost-effective because an imagination unit for color toner could be installed later as needed.

According to the present invention, development can be switched by a simple method of moving one developing unit, and damage to the belt photoreceptor at the time of switching can be avoided.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a copying machine having a developing device according to the present invention, and FIG. 2 is a schematic diagram showing a state in which the second developing unit/nod is moved. DESCRIPTION OF SYMBOLS 1... Belt photoreceptor 10... First developing unit 11... Second developing unit 12... Frame 13a, 1
3b, 13cm...Developer chamber 15a, 15b,
15c...-Developing roller 19...Casing 23
...To the developing roller ■-7 Fu

Claims (1)

[Claims] A rotatable frame having a plurality of developing units arranged along a travel path of a belt-shaped photoreceptor that forms an electrostatic latent image, and one developing unit having a plurality of developer chambers divided in the circumferential direction. and a developing roller rotatably supported at the opening of each developer chamber, and another developing unit has a developing roller that is movable toward and away from the belt-shaped photoreceptor. Copying machine developing device.