JPH11219009A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device which, irrespective of an amount of supplied toner, prevents toner agglomeration and deterioration and is less in the occurrence of dead toner. SOLUTION: A toner carrying member is composed of a core shaft 8 and a large number of bristles 9 attached to the core shaft 8. In the state where toner consumption is less and toner supply is excessive, the bristles 9 are overwhelmed by the pressure of the toner gathering on the side of a replenishment roller 2 and incline backward in the direction of the rotation of the core shaft 8, so that a gap is made open between the internal-face bottom of a case 4 and them and an amount of carrying, therefore, decreases to prevent toner agglomeration which is caused by toner further pushed in despite the excessive supply of toner. On the other hand, in the state where the amount of toner consumption is large and the amount of supply is insufficient, the bristles 9 carry the toner without being overwhelmed by the pressure of the toner gathering on the side of the replenishment roller 2, and make it possible to maintain proper image-density.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer,
The present invention relates to a developing apparatus for an electrophotographic apparatus such as a facsimile, and more particularly, to a developing apparatus for a dry one-component toner.

[0002]

2. Description of the Related Art In recent years,
In the field of small electrophotographic devices such as copiers, the simplification of maintenance has been progressing, and various types of one-component developing systems have been put into practical use. As a result, users can easily replace them without soiling their hands with toner. The development of a supply unit integrating a developing device and a toner cartridge is progressing.

A unit in which a developing unit and a toner cartridge are integrated is filled with toner. The toner is consumed by image output (development), but the conveyance and supply of the toner in the unit are not sufficient. However, there is a problem that a desired image density cannot be obtained, and a residual toner (dead toner) at the time of unit replacement is increased.

Therefore, conventionally, there has been generally adopted a system in which a conveying member formed of a shaft made of metal or plastic and a blade made of mylar is rotated in a unit to convey toner near a developing section. In this method, the toner conveying member rotates even during the operation of the developing device,
Since the toner is sent to the developing unit regardless of the amount of toner consumption, when the toner consumption is small, the toner supply to the vicinity of the developing unit becomes excessive. However, there is a problem that the toner leaks from the toner or promotes the aggregation of the toner, and as a result, the image quality is deteriorated such as the dot reproducibility is lowered.

To cope with this problem, for example, as shown in a toner conveying member 20 shown in FIG. 4, a hole 23 is formed in a blade 22 attached to the rotating shaft 21 or the angle of the blade is inclined to reduce the toner conveying amount. However, in such a case, there is another disadvantage that the supply of toner cannot catch up immediately after consuming a large amount of toner, and a desired image density cannot be obtained.

Further, in order to reduce the dead toner, it is necessary to scrape and supply the toner accumulated at the bottom of the case of the developing device. There is also a problem that abnormal noise is generated and the rubbed toner is physically deteriorated to deteriorate the image quality.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide a developing device which does not cause aggregation and deterioration of toner and has less dead toner.

[0008]

According to a first aspect of the present invention, there is provided a developing apparatus comprising: a developing unit, a case filled with a one-component toner, and a developing unit which is rotated while rotating; A toner conveying member that conveys the toner to the vicinity of the unit, wherein the toner conveying member includes a rotating shaft and a blade for conveying toner, and the blade has a large number of flexible bristles implanted on the rotating shaft. It is characterized by comprising a shape.

According to a second aspect of the present invention, the tip of the hair in a non-deflected state contacts the bottom of the case.

According to a third aspect of the present invention, the hair is conductive.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the developing device according to the present invention. In the figure, 1 is a developing roller, 2 is a replenishing roller, 3 is a toner conveying member, 4 is a case, and the developing roller 1, the replenishing roller 2, and the toner conveying member 3 are a case 4
Are supported by side plates (not shown). The toner is supplied to the surface of the developing roller 1 via the toner conveying member 3 and the supply roller 2.

In FIG. 1, reference numeral 5 denotes a toner layer forming member, and 6 denotes a photoreceptor. The toner supplied onto the developing roller 1 is thinned to a predetermined thickness by the toner layer forming member 5. It is conveyed to the photoconductor 6 with rotation. The developing roller 1 is pivotally supported so as to be in parallel contact with the photoconductor 6.
A bias voltage substantially intermediate between the charged potential of the photoconductor 6 and the residual potential after optical writing (after exposure) is applied via the leaf spring electrode 7. Then, the toner on the developing roller 1 is transported to the contact portion with the photoconductor 6, and the charged toner adheres to the photoconductor 6 in accordance with the developing electric field due to the photoconductor potential and the developing bias, and an electrostatic latent image is formed. It is visualized.

As shown in detail in FIG. 2, the toner conveying member 3 comprises a core shaft 8 and a number of hairs 9 implanted on the core shaft 8. The toner conveying member 3 of the present embodiment also has a function of maintaining a desired image density by newly conveying toner consumed (developed) by image output to the vicinity of the replenishing roller 2. Similarly, regardless of the amount of toner consumption, the mechanism always rotates when the developing device is in operation.

That is, the toner conveying member 3 of the present embodiment
As shown in FIG. 3A, in a state where the toner consumption is small and the toner supply is excessive, the hair 9 loses the pressure of the toner collected on the replenishing roller 2 side and the hair 9 is located on the rear side in the rotation direction of the core shaft 8. The distance between the case 4 and the bottom of the inner surface of the case 4 is increased, thereby reducing the transport amount. As a result, aggregation of the toner caused by further pushing the toner in a state in which the toner is excessively supplied can be prevented, and the problem that the reproducibility of dots and thin lines due to the aggregation deterioration of the toner is reduced does not occur.

In the toner conveying member 3 of the present embodiment, as shown in FIG. 3B, when the toner consumption is large and the supply amount is insufficient, the hairs 9 are gathered on the supply roller 2 side. Since the toner is conveyed without losing the pressure of the toner, an appropriate image density can be maintained even when toner consumption is large.

Further, the toner conveying member 3 of the present embodiment
The tip of the hair 9 comes in contact with the bottom of the inner surface of the case 4 in a state where the toner supply amount is small. However, since the hair 9 is flexible, no unpleasant noise is generated. Further, the toner accumulated at the bottom of the case 4 can be conveyed to the developing unit without applying excessive force, and the dead toner can be reduced and the toner can be effectively used without physically deteriorating the toner. Can be.

If the hair 9 is made of a conductive material,
Since toner sticking due to frictional charging with toner is prevented, the life of the toner conveying member 3 is extended.

[0018]

According to the first aspect of the present invention, as described above, the toner conveying member includes a rotating shaft and a plurality of flexible hairs implanted on the rotating shaft. When the toner consumption is small, the hairs are bent and the amount of supplied toner is reduced, so that toner aggregation due to excessive toner supply and deterioration of image quality caused by the toner supply are prevented, and toner consumption is reduced. There is an effect that a shortage of supply does not occur even when the amount is large.

According to the second aspect of the present invention, as described above, the bottom of the case and the tip of the non-deflected hair are in contact with each other. And the toner can be used up effectively.

As described above, the developing device according to the third aspect uses the hairy material having conductivity, so that in addition to the above-described common effects, it is possible to prevent the toner from sticking due to frictional charging. There is an effect that.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a developing device according to the present invention.

FIG. 2 is a perspective view of a toner conveying member of the developing device of FIG.

FIG. 3A is a cross-sectional view showing the operation of the toner conveying member of the developing device in FIGS. 1 and 2 in a state where toner consumption is small and toner is excessively supplied, and the toner consumption is large and the supply amount is insufficient. It is sectional drawing (B) which shows operation | movement in a state.

FIG. 4 is a perspective view of a toner conveying member of a conventional developing device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 developing roller 2 replenishment roller 3 toner transport member 4 case 5 toner layer forming member 6 photoreceptor 7 leaf spring electrode 8 core shaft 9 hair

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Taisuke Tokuwaki 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Company, Ltd.

Claims (3)

[Claims] A developing unit, a case filled with one-component toner, and a toner conveying member that conveys the toner to the vicinity of the developing unit while rotating, wherein the toner conveying member includes a rotating shaft, a toner conveying member, And a blade having a plurality of flexible hairs planted on the rotating shaft. 2. The case according to claim 1, wherein the bottom of the case contacts the tip of the hair which is not bent.
Developing device. 3. The developing device according to claim 1, wherein said hair has conductivity.