JPS634224Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer stirring device in a developing section of a copying machine, and more particularly to a stirring device for effectively stirring a two-component developer.

In a copying machine that uses a two-component developer, a developer consisting of iron powder called a carrier and toner, which is a colored pigment, it is necessary to replenish a developer tank with toner, which is a consumable material, at regular intervals. Then, the replenished toner is sufficiently agitated with the carrier, and the agitated developer is sent to a developing roller or the like for development. Various toner replenishment devices or stirring devices have been proposed for this purpose.
However, sufficient characteristics have not been obtained regarding convenience of replenishment, speed of toner transfer after replenishment, and stirring performance.

For example, FIG. 1 shows a conventional developer stirring device in which a toner replenishing section is provided opposite one end of a developer tank and two screw rollers for stirring and toner transport are provided. In this figure, a toner replenishing section 1 is provided facing one end of a developer tank 2. As shown in FIG. Therefore, this toner replenishing section 1 is superior in terms of serviceability, usability, and miniaturization, compared to a toner replenishing section that is provided opposite to the entire developing tank 2 and replenishes toner. The toner replenished from the replenishing section 1 is sent in the direction of arrow A by a first screw roller 3 rotatably provided in the developer tank 2, and reaches the end opposite to the toner replenishing section 1. do. During this time, the replenished toner is sufficiently agitated with the carrier by the rotation of the fins of the screw roller 3, and is agitated and conveyed so that there are no toner lumps or the like. next,
When the developer at the end conveyed by the first screw roller 3 reaches a certain amount, it is transferred to the adjacent second screw roller 4 and directed toward the previous toner replenishment port in the direction of arrow B. sent back. The fins of the second screw roller 4 have a larger pitch than the fins of the first screw roller.
The carrier's developer is fed faster. This is because the second screw roller 4 has the function of thoroughly supplying the agitated developer to the developing roller 5, and the function of returning the toner to the carrier and unnecessary toner replenishment port, rather than making the agitation more thorough. This is because all you have to do is demonstrate.

The toner is stirred by the above-mentioned action, but if a certain amount of developer does not accumulate at the end of the developer tank 2 opposite to the toner supply section 1, the second screen Since the developer is not transferred to the Euroroller 4, there are disadvantages in that the transfer of the developer is slow and uneven stirring tends to occur.

The present invention solves the above drawbacks with a simple configuration and provides a device that satisfies the important points of the above-mentioned stirring device: convenience in toner replenishment, speed of toner transfer after replenishment, and stirring function.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a perspective view of a stirring device that is an embodiment of the present invention. In the figure, reference numeral 6 denotes a toner replenishment part that is provided opposite to the replenishment port at one end of the developer tank 7 and replenishes toner at regular intervals, and 8 is a first screw rotatably provided in the developer tank 7. Laura, 9 is the first
This is a second screw roller rotatably provided in the developer tank 7 adjacent to the screw roller.
The first screw roller 8 is the toner supply section 6
Screw fins 10 at a constant pitch are provided on the surface of the roller to agitate and convey the toner and carrier. In addition, the end of the screw fin 10 of the present invention, that is, the end 10-1 on the opposite side from the toner replenishing section, has an inverted screw fin shape as shown in the figure. Further, the second screw roller 9 is provided with screw fins 11 having twice the pitch of the screw fins 10 of the first screw roller 8 on the roller surface. Therefore, both rollers 8 and 9
If they rotate at the same speed, developer roller 9
The transport speed by the roller 8 is twice that of the roller 8. Incidentally, gears 12 and 13 that mesh with each other are fixed to one end of the roller shafts 8-1 and 9-1 of each of the rollers 8 and 9. Further, the gear 13 meshes with a gear 14 to which driving force is transmitted from a drive source (not shown), and rotation of the gear 14 in the direction of the arrow causes each of the rollers 8 and 9 to rotate in the direction of the arrow. Each gear 12, 13, 14 is housed in a gear box 15.

Further, reference numeral 16 is a developing roller that attracts the stirred developer by magnetic attraction and conveys the developer to a developing area facing a photoreceptor (not shown) on which an electrostatic latent image is formed. It is rotated in the direction of the arrow to convey the developer.

In the above configuration, the toner supplied from the toner supply section 6 is agitated with the carrier in the developer tank 7 by the screw fin 10 of the first screw roller 8, and is transferred in the direction of arrow A. Then, the developer is given reverse rotation (transfer force) by the reverse direction fin 10-1 near the end in the transport direction, and is transferred to the second screw roller 9 at the cut portion C of both fins. will be forcibly sent to Therefore, at the end of the transfer of the developer from the first screw roller 8 to the second screw roller 9, the developer does not accumulate as in the conventional case, and is smoothly transferred to the second screw roller. 9, it is possible to prevent delays in toner transfer and also to prevent uneven stirring of toner and carrier due to accumulation. The developer sent to the second screw roller 9 is conveyed toward the toner replenishing section in the direction B at twice the speed, and at the same time, is completely supplied to the developing roller 15.

Although a screw roller is preferable as a means for transporting toner and carrier, the present invention can be applied to other methods as well. Further, the screw fin 10-1 in the opposite direction provided at the end of the first screw roller 8 may be further provided on the toner replenishing section side of the second screw roller 9. In this way, the circulation of toner and carrier within the developer tank 7 can be carried out more effectively.

As described above, according to the developer stirring device of the present invention,
Since a member for transferring in the opposite direction is provided at one end of the first transfer means, it is possible not only to smoothly send the well-stirred developer to the second transfer means, but also to transfer the developer that has been sent to the second transfer means. The second transfer means adjacent to the developing roller, which has a faster transfer speed, can quickly supply the developer to the developing roller, which has a great effect of quickly supplying fresh, agitated developer to the entire area in the direction of the rotation axis of the developing roller.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional developer stirring device;
FIG. 2 is a perspective view showing an embodiment of the developer stirring device of the present invention. 6... Toner supply unit, 8... First screw roller, 9... Second screw roller, 10...
... Screw-in, 10-1 ... Screw-in in the opposite direction to Screw-in 10, 11...
Scryeufin.

Claims (1)

[Claims for Utility Model Registration] 1. In a developer stirring device that supplies stirred developer to a developing roller in order to develop an electrostatic latent image formed on a recording medium, the toner to be replenished is mixed with a carrier and stirred. At the same time, a first transfer means provided with a member that transfers the developer toward one end and a member that transfers the developer in the opposite direction at the transfer end, and between the first transfer means and the developing roller. A second transporting means is provided with a member for transporting the developer, which is arranged and transported in the opposite direction at the transporting end, toward the other end at a faster speed than the first transporting means and supplies it to the developing roller. A developer stirring device characterized by comprising a transporting means. 2. The developer stirring device according to claim 1, wherein the pitch of the developer transfer member of the second transfer means is larger than the pitch of the transfer member of the first transfer means.