JPH04157487A - Stirring apparatus of two-component developer - Google Patents

Abstract

PURPOSE:To shorten the time required for stirring for uniform dispersion of a supplied developer by providing a developer supply port at the central position in the direction to juxtapose two pieces of carrier screws on the upper surface of a container. CONSTITUTION:A developer supply port 16 is provided at the central position in the direction to juxtapose two pieces of carrier screws 10a, 10b. As the developer supply port 16 is provided at the central position in the direction to juxtapose two pieces of the carrier screws 10a, 10b, when a developer 28 is input from this supply port 16, the developer 28 falls on the respective carrier screws 10a, 10b, and the developer 28 having fallen on each of the carrier screws 10a, 10b which rotate in the reverse direction each other is circulated in the specified direction. The route (time) required for the developer 28 to extend all over in a container 12 comes to be shorter in comparison with the case when the input developer 28 falls on one of the carrier screws. Consequently, it is possible to shorten the time required for stirring for uniform dispersion of the supplied developer.

Description

[Detailed Description of the Invention] = Overview: This invention relates to a stirring device for two-component developer used in an electrophotographic device, with the purpose of shortening the time required for stirring and uniformly dispersing the supplied developer. A stirring device for a two-component developer used, which stirs and mixes the two-component developer, and
two conveyance screws that are arranged close together and rotate in opposite directions; a container that surrounds the conveyance screws and accommodates the developer; = - A developer supply port provided at a central position in the direction of juxtaposition.

[Industrial application field]

The present invention relates to a two-component developer stirring device used in an electrophotographic apparatus.

2. Description of the Related Art: In order to electrostatically deposit toner on a drum in an electrophotographic apparatus, it is necessary to charge the toner.

As a method of charging this toner, there is a method of stirring and mixing iron powder called Chiaria and carbon that is the toner, and simultaneously charging the toner with friction. A conveying screw is often used to stir this two-component developer.

The transport screw and the container housing the developer have an outlet for discharging deteriorated developer and a developer supply port for supplying new developer. The supply port is also used for supplying only used toner. Each component of the supplied developer must be sufficiently agitated and mixed with the other component, and for this reason, a supply port is provided on the conveying screw and the developer is dropped onto the conveying screw for stirring. In order to sufficiently stir the developer, a method has been adopted in which two conveyance screws are provided and rotated in opposite directions to circulate and stir the developer.

[Problems to be Solved by the Invention] However, when toner is replenished or new developer is supplied, these are uniformly stirred by the rotation of the conveying screw, and the developer is not deposited in the container. Depending on the position of the developer supply port, it takes a considerable amount of time to distribute the developer, and the electrophotographic apparatus cannot be used during this time, which is an inconvenience.

Therefore, an object of the present invention is to shorten the time required for stirring and uniformly dispersing the supplied developer.

[Means to solve the problem]

In view of the above object, the present invention provides a two-component developer agitation device used in an electrophotographic apparatus, which agitates and mixes the two-component developer, and which is arranged close to each other and rotates in opposite directions. two transport screws; a container surrounding the transport screws and accommodating the developer;
A two-component developer stirring device is provided, characterized in that the developer supply port is provided on the upper surface of the container at a central position in the direction in which the two conveyance screws are arranged side by side.

[For Police] The developer supply port is located at the center of the two transport screws, so when developer is introduced from this supply port, the developer falls onto each transport screw and flows in opposite directions. The developer that has fallen onto each rotating transport screw circulates in a predetermined direction, but the path (time) it takes for the developer to spread throughout the container is such that the developer that has been put in only flows onto one transport screw. It will be shorter than it would be if it fell.

〔Example〕

The present invention will be described in more detail below based on embodiments shown in the accompanying drawings.

Referring to FIGS. 1 and 2, the container 12 includes a pair of conveying screws 10a with a separating wall 26 interposed therebetween.
10b is located nearby. Each conveyance screw 10
a and 10b rotate in opposite directions, and the developer placed on each conveyance screw circulates on the pair of conveyance screws along a conveyance trajectory that draws a closed loop. A developer supply port 16 is provided on the upper surface of the container 12, at a central position in the direction in which the pair of conveyance screws 10a and 10b are arranged side by side, and at a central position in the longitudinal direction of the conveyance screws. New developer can be supplied. In this case, the toner and developer 28 will fall onto each transport screw. A discharge port 14 for discharging deteriorated developer is provided on the lower surface of the container 12, and is normally closed by a lid member 15 called a shutter. When supplying new developer, first
Of course, it is necessary to discharge the deteriorated old developer from step 4.

A supply roller 1 is placed in front of the pair of conveyance screws in the direction in which they are arranged side by side.
8 and a magnet roller 2o are provided in parallel to the conveying screw, and a drum 3o is further provided in front of the conveyance screw and outside the container 12. In order to evenly adsorb the developer stirred by the conveyance screw onto the surface of the magnet roller 2o via the supply roller 18,
Conveyance screw 10a.

It is necessary to distribute the developer evenly in the longitudinal direction of the conveyor screw 10b, and among the replenished toner and developer 28, those that have fallen onto the conveying screw 10a are moved while being agitated by the trajectory shown by the line 22. , transport screen lJ knee 1
0b, the developer must be stopped from being supplied to the magnet roller 20 by the supply roller 18 until it moves along the trajectory shown by the line 24, and during that time the electrophotographic apparatus itself must not be operated. I can't do it.

However, referring to FIG. 3 which mainly shows a conventional type stirring device, the supply port 16 is connected to one of the conveying screws 10a.
In order for the injected toner or developer to spread all over, it must move along the trajectory shown by line 23. This travel time is calculated by the two transport rollers 10a and 10b.
Since the travel time in the case of the present invention corresponds to the length corresponding to line 22 (or 24), it can be seen that the present invention takes only half the time compared to the conventional one.

This is due to the fact that the supplied toner or developer is divided and dropped onto each of the conveying screws 10a and 10b, which rotate in opposite directions 5). Considering the homogenization of the developer after stirring, it is most desirable that the supply port 16 is located not only at the center position in the direction in which the conveying screws 10a40b are arranged, but also at the center position in the length direction, as shown in FIG. It is within the scope of the present invention that the position (b) is slightly biased to one side from the central position in the longitudinal direction.

Effects of the Invention As is clear from the above description, according to the present invention, the time required for stirring and uniformly dispersing the supplied toner and developer can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a perspective view mainly showing a stirring device according to the present invention, FIG. 2 is a sectional view taken along arrow line 1-I in FIG. 1, and FIG. 3 is a perspective view mainly showing a conventional stirring device. . 10a, 10b... Conveyance screw, 12... Container, 16... Supply port, 28... Supplied developer.

Claims (1)

[Scope of Claims] 1. A two-component developer stirring device used in an electrophotographic apparatus, which stirs and mixes the two-component developer (28), and which is arranged in close proximity and in opposite directions. Two rotating transport screws (10a, 10b); A container (12) surrounding the transport screws and accommodating the developer; and an upper surface of the container in the direction in which the two transport screws are arranged side by side. A two-component developer stirring device characterized by comprising a developer supply port (16) provided at a central position. 2. The two-component developer stirring device according to claim 1, wherein the developer supply port is provided at a central position in the direction in which the two transport screws are arranged side by side, and at a central position in the longitudinal direction of the transport screws.