JPS6015072B2 - developer supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer replenishing device for a liquid type electrophotographic copying machine.

In a wet type electrophotographic copying machine, as shown in FIG. 1, a concentrated developer A, which is a developer, which is fed from a concentrated developer tank 101, is added to a developer mother solution stored in a developer tank 100. A developer B having a constant concentration is obtained, and development is performed using this developer B.

When development is performed, the developer tank 10
The concentration of the developer B in 0 decreases, and the amount of the developer B decreases as it is gradually consumed. When the developer B decreases in this way, the developer mother solution is replenished as appropriate. Then, in order to prevent the concentration of the developer from decreasing due to the execution of development and the replenishment of the developer mother solution, the concentrated developer A is poured into the developer tank 100.
Replenishment will be carried out. The above-mentioned conventional technology regarding the replenishment of concentrated developer A consists of two main components:
Each had their shortcomings.

{11 One of the two components described above is a tube 103 and a venturi tube 1 that connect the bottom of the concentrated developer tank 101 and the outlet side pipe section 102a of the venturi tube 102.
02, and the like. Fluid always flows through the Venturi tube 102 at high speed. For example, developer B is used as this high-speed fluid.
This liquid B is led to the Venturi tube 102 by an inlet pipe 105a, passes through this, and is then spouted into the developer tank 100 through a delivery pipe 105b. Now, when the developer concentration decreases, a control signal is applied to operate the control solenoid 106, which rotates the swinging arm 108 so that one end
Pipe 107 passing 07a through outlet side port pipe 102a
The air intake hole 107b at the other end is closed. As a result, a larger negative pressure is generated in the outlet-side expanded tube portion 102a, and the concentrated developer A in the concentrated developer tank 101 is sucked by this tank pressure, and the developer tank 100 is also guided. The disadvantage of this configuration is that when the concentrated developer tank 101 is empty, the concentrated developer A cannot be absorbed by the negative pressure of the Venturi tube 102, and especially the toner contained therein is not sucked up to the bottom of the concentrated developer tank 101. Otherwise, it may remain inside the tube 103 and become stuck.

If toner sticks to the developer tank 101 for one day, even if the concentrated developer tank 101 is replenished with the concentrated developer A, the developer tank 100 cannot be replenished due to the stuck toner. '2} Other configurations include the concentrated developer tank 10
1, and a bottle 109 attached to this tank 101 to supply concentrated developer A thereto.

Note that a cylindrical bottle cap 111 is attached to the mouth of the bottle 109. A valve 111a is built into the bottle cap 111 and is maintained in a normally closed state by a spring 111b. On the other hand, the concentrated developer tank 101 is attached by fixing the upper end of its side wall to the upper lid 110' of the developer tank 100. A mounting hole 110a for inserting a bottle cap 111 is provided in a part of the upper lid 110 facing the concentrated developer tank 101.
is formed. When the bottle 109 is attached, the convex portion 101a provided at the bottom of the concentrated developer tank 101
pushes the valve 111a to open it, so that the bottle 109 and the concentrated developer tank 101 are in communication. As the developing operation is repeated, the concentrated developer tank 101
As the concentrated developer A in the bottle 109 decreases, concentrated developer A is automatically replenished from the bottle 109. Then, the liquid level level bell L-L in the concentrated developer tank A is maintained at the same level as the tip surface of the bottle cap 111. By the way, the amount of concentrated developer in the bottle 109 is limited. Therefore,
When the liquid in the bottle 109 becomes insufficient, Wataru bottle 10
9 must be pulled out from the mounting hole 110a and filled with concentrated developer. At the time of this pulling out, the bottle cap 11 inside the bottle cap 111 and the valve seat of the valve 111a.
The liquid remaining within the range between the top end surface of the developer and the developer will flow into the concentrated developer tank 101 and will be excessively replenished. Therefore, the liquid level and the bell L-L rise by that amount. When the bottle is replaced several times in this way, the residual liquid is replenished in excess each time, until the liquid level reaches the bell L-L.
exceeds the upper end of the side wall of the concentrated developer tank 101.
In this way, the concentrated developer A overflowing from the concentrated developer tank 101 flows out onto the developer tank 100 through the mounting hole 110a, seriously staining the tank 100 and associated equipment. The purpose of this invention is to solve the above problem 1' that occurs when there is an excess or shortage of concentrated developer supplied to the concentrated developer tank.
It is an object of the present invention to provide a developer replenishing device which eliminates the drawbacks mentioned in (2) above.

Embodiments of the present invention will be described in detail below with reference to FIGS. 2 and 3.

In addition, in the drawings, parts indicated by the same reference numerals as those shown in FIG. 1 are treated as having the same shapes and functions as those already explained using the reference numbers. The structural features of the present invention are as follows: (1) A part of the side wall of the concentrated developer tank 1 installed in the developer tank 100 is cut out to protrude a shelf-like eaves 2 to form a developer circulation surface F. .

(2) A developer circulation device 3 is provided which sucks a part of the developer B and circulates it back into the developer, and its discharge port 3a is positioned above the eaves 2. It can be summarized in two points. The eaves portion 2 will be further explained. The eaves portion 2 has a slight horizontal surface portion, that is, a developer circulation surface F, and its free end extends reliably into the developer tank 100. Further, the developer circulation surface F is located in a space region t that is lower than the upper lid 110 and higher than the tip end surface of the bottle cap 111.

On the other hand, the developer circulation device 3 includes a pump P, and a suction pipe 3b and a discharge pipe 3c, each of which has one end connected to a suction port and a discharge port of the pump P. The other end of the suction pipe 3b is inserted into the developer B in the developer tank 100, and the discharge port 3a, which is open at the reservoir end of the discharge pipe 3c, is placed on the developer recirculation surface F. located and installed. Next, bottle 10
The effects of the present invention will be described when the concentrated developer A supplied from 9 is in excess and when it is not replenished.

(a) When concentrated developer A is not replenished.

With the above configuration, the developer B is always discharged from the discharge port 3a to the developer recirculation surface F on the eaves part 2. This developer B is divided on the developer reflux surface F, and one of the divided liquids 4a flows down into the concentrated developer tank 1, and the other divided liquid 4b flows back into the developer tank 100. There is.
Assume that the bottle 109 is now empty and supply to the concentrated developer tank 1 has been cut off. However, since the diverted liquid 4a constantly flows into the concentrated developer tank 1 and moistens the bottom of the tank 1 and the pipe 103, the toner is
There is no possibility that it will become stuck. Note that when the bottle 109 is filled with the concentrated developer A, due to the difference in specific gravity, the concentrated developer A occupies the area below the tip of the bottle cap 111 in the concentrated developer tank 1, and the area above it is occupied by the developer, which is a divided liquid. It is dominated by liquid B.

Considering this situation, the concentrated developer A in the concentrated developer tank 1 is transferred to the tube 103 by the Venturi tube 102.
In order to ensure that the concentrated developer A in the bottle 109 is refilled into the concentrated developer tank 1 when the concentrated developer A is sucked through The amount of developer B is set to be smaller than the amount of liquid sucked into the venturi tube. {b} When concentrated developer A is excessively replenished.

When the concentrated developer tank is overfilled, the surplus concentrated developer A flows on the developer reflux surface F and quickly flows down to the developer tank 100. A situation such as overflowing onto the developer tank 100 and staining the surrounding area does not occur. Incidentally, changes in the concentration of the developer B due to the above-mentioned excessive replenishment can be adjusted by appropriately adding a developer mother solution.

Further, the developer circulation surface F is not limited to the horizontal surface formed on the canopy portion 2 as shown in the figure, but may be formed, for example, in the shape of a mountain-shaped roof or in the shape of an arcuate convex surface. Alternatively, a plate piece supported by an immovable member may be provided below the discharge port 3a. In short, any shape may be used as long as it can fulfill the function of dividing the developer B. As explained above, according to the present invention, the concentrated developer A supplied from the bottle 109
This is beneficial because it can prevent various damage caused by excess or deficiency of.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a developer replenishing device according to the prior art, FIG. 2 is a side sectional view of a developer replenishing device according to the present invention, and FIG. 3 is a perspective view showing essential parts of the present invention. 1...Concentrated developer tank, 3...Developer circulation device, 3a...Discharge port, 4a...
・One branch liquid, 4b...The other branch liquid, 10
0...Developer tank, F...Developer reflux surface. I don't like it! Figure 12 Zuzozo 3

Claims (1)

[Claims] 1. In an electrophotographic copying machine that adds a concentrated developer from the concentrated developer tank to the developer mother solution stored in the developer tank to obtain a developer of a certain concentration, and performs development with this developer, A developer reflux surface is formed on a part of the side wall of the concentrated developer tank to be installed, and when the concentrated developer tank is overfilled with concentrated developer, the surplus concentrated developer flows over the developer reflux surface. A developer circulation device is installed such that the discharge port of the developer circulation device is arranged so that the developer flows and escapes into the developer tank, and also sucks a part of the developer and circulates it back into the developer, so as to be located on the developer recirculation surface; The developer discharged from this discharge port is divided at the developer reflux surface, one of the divided flows flows into the concentrated developer tank, and the other divided flow flows back into the developer tank. Characteristic developer replenishment device.