JPH056193B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a developing device used in a dry electrophotographic apparatus.

(Prior art) A developing device using radial conveying blades a as shown in FIG. 1 as a developing device using a two-component developer has the advantage of simplifying the device and reducing costs. Since the stirring action is mainly limited to the circumferential direction, there are problems such as poor ability to charge the supplied toner and background smearing.Additionally, separate cross mixing is required to stir the developer in the lateral direction. Since mechanism b is required, there is a problem in that the device becomes larger.

On the other hand, in the device disclosed in Japanese Patent Application Laid-open No. 55-42736, two augers are installed in the axial direction of the developing roller to circulate the developer in the storage tank in the axial direction. However, there are problems in that the circumferential stirring function is poor and the developer cannot be sufficiently supplied to the developing roller.

(Purpose) The present invention has been made in view of the above problems, and its purpose is to provide a developing device with a simple structure that has not only a circumferential stirring function but also an axial circulation and stirring function. It is about providing.

(Means for Achieving the Object) That is, the present invention provides a dry developing device for achieving the above object, which includes radial blades that supply developer to a developing roller, and developer that is distributed around the outer periphery of the radial blades. A rotary body having a transport blade that transports the rotor in the axial direction is disposed in parallel and close to the developing roller in a developer storage tank having an inner surface that at least partially follows the outer periphery of the rotary body; A developer transfer chamber with developer inlets and inlets at both ends is arranged adjacent to the developer storage tank and parallel to the rotating body, and the developer is transferred into the chamber in the opposite direction to the direction in which the transfer blades transfer the developer. The device is equipped with a means for transporting.

(Example) The details of the present invention will be described below based on illustrated examples.

2 to 4 show an embodiment of the present invention, in which reference numeral 1 denotes a stirring impeller arranged parallel to and close to the developing roller 10. The developer in the storage tank 12 is transferred to the developing roller 1.
A radial impeller 3 is integrally formed to feed the water while stirring the impeller 1, and a storage tank 12 is formed along the outer periphery of the impeller 1.
It is surrounded by a spiral developer axially transporting blade 4 for transporting the developer accumulated between the inner wall surface and the inner wall surface in the axial direction from one end to the other end. 6
is a developer transfer chamber provided close to and behind the above-mentioned transport impeller 1, and a partition wall 7 provided between the developer storage tank 12 and the developer storage tank 12 has a developer inlet 8 at one end.
However, an outlet 9 is provided at the other end, and a conveying screw 5 for conveying the developer in the opposite direction to the conveying blade 4 is arranged so as to rotate in the same direction as the impeller 1 or in the opposite direction. It is configured so that the developer flowing in from the inlet 8 and the toner replenished from the toner tank 13 are sent out toward the outlet 9 at the other end.

In the figure, reference numeral 11 indicates a doctor blade for aligning the ears of the magnetic brush formed on the developing roller 10 to a constant height, and 14 indicates an inlet for recycled toner.

In the embodiment described above, when the conveying impeller 1 rotates in the direction of the arrow in the figure, the impeller 3 draws up the developer in the storage tank 12 and supplies it to the developing roller 10 while agitating it in the circumferential direction. On the other hand, with this rotation, the spiral transfer blades 4 surrounding the outer periphery of the impeller 1 transfer the developer in the developer tank 12 from right to left in the figure.
The developer is introduced into the transfer chamber 6 through an inlet 8 located at the end of the shaft 2 in collaboration with the conveyor blades 3 and behind them.

In this embodiment, a toner tank 13 is provided above the inlet 8, and toner is replenished from there in accordance with the output signal of the toner concentration sensor. The rotating conveyance screw 5 agitates and mixes the developer that has flowed into the inflow port 8 and the replenished toner, while moving the toner in the direction opposite to the direction of transport by the transport blades 4, that is, the outflow port that opens at the right end in the figure. Thereafter, the developer is supplied to the developing roller 10 while being circulated in the axial direction one by one from left to right and right to left by the transport blade 4 and the transport screw 5.

Although the above description is for a type of device in which toner is replenished to one end of the storage tank 12, similar agitation and mixing can be performed in a device in which toner is replenished over almost the entire width of the storage tank 12. can be set.

(Effects) As described above, according to the present invention, the rotating body is provided with transfer blades for further transferring the developer in the axial direction on the outer periphery of the radial blades. Since the developer storage tank has an inner surface and is placed close to the developing roller, the radial blades in the area close to the developing roller send out the developer in the radial direction and send it to the developing roller. In addition to efficiently supplying
On the inner surface of the storage tank along the rotating body, the developer sent out in the radial direction by the radial vanes is collected between the rotating body and the inner surface of the storage tank.
Together with the developer supplied in the opposite direction to the transport direction, this can be efficiently mixed and stirred while being transported in the axial direction by the outermost transport blade.
Furthermore, a member for transferring the developer in the opposite direction to the direction of transfer by the rotating body is provided in the transfer chamber provided with the inflow opening and the inflow opening, making it possible to circulate the developer in the axial direction within the developer tank. Therefore, it is possible to ensure uniform density image formation. Moreover, since these agitation, mixing and circulation can be performed only by the rotating body and the transfer member, the developing device can be significantly downsized and simplified.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a conventional device;
FIG. 2 is a block diagram of an apparatus showing an embodiment of the present invention, and FIGS. 3 and 4 are side views of a conveying impeller and a conveying screw in the same apparatus. 1... Conveyance impeller, 2... Sleeve shaft, 3...
Conveyance blade, 4...Transfer blade, 5...Transfer screw, 6...Transfer chamber, 8...Inlet, 9...Outlet, 10...Developing roller.

Claims (1)

[Claims] 1. A rotating body including radial blades that supply developer to a developing roller and transfer blades that transport the developer in the axial direction around the outer periphery of the radial blade, at least partially along the outer periphery of the rotating body. The developer storage tank is arranged close to and parallel to the developing roller in a developer storage tank having an inner surface such as 1. A dry type developing device, characterized in that means is disposed in the vicinity of the rotating body in parallel, and within the chamber, means for conveying the developer in a direction opposite to the conveying direction of the conveying blade.