JP2002278270A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device which autonomously adjusts the conveyance amount of a developer irrelevantly to the deviation direction of the developer and holds the balance of the amount of the developer constant. SOLUTION: A balance 84 which can slant corresponding to the deviation of the amount of the developer is provided before the place where the developer flows in a fin 81. While the developer deviates to a side F, the amount of the developer scooped up onto a separator 8 also deviates to the side F, so a force pressing the balancer 84 deviates and the balancer slants toward α. Consequently, the amount of the developer flowing on the separator 8 is large on the side F and small on a side R, so the amount MA of the developer carried to the side R by the fin 81 is larger than the amount MB of the developer carried to the side F by a conveyor screw 9, so that the developer having deviated to the side F is returned to the side R.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device mounted on an image forming apparatus such as a copying machine, a facsimile, a printer, and a direct digital plate making machine using an electrophotographic system. The present invention relates to an improvement in a stirring mechanism in the axial direction of a carrier.

[0002]

2. Description of the Related Art In a conventional developing device using a two-component developer composed of a carrier and a toner, a developing device conveyed from a developer carrier to a latent image on a latent image carrier is used. Toner is consumed. Since the potential distribution of the latent image in the axial direction of the developer carrier is usually non-uniform, the toner consumption from the developer on the developer carrier also becomes non-uniform,
The developer on the developer carrier after development has a difference in toner concentration in the axial direction of the developer carrier.

Therefore, in a conventional developing device, in order to supply a developer having a uniform toner concentration in the axial direction of the developer carrying member,
The so-called horizontal stirring is performed in the axial direction. As a mechanism for the lateral stirring of the developer, a plurality of the developer scraping members are disposed on a separator as a developer flowing-down member for receiving and flowing down the developer scraped from the developer carrier by a doctor blade as a developer regulating member. A fin as a skew member for skewing the developer flowing on the separator in a direction orthogonal to the developer carrier axis direction, and receiving a part of the developer on the separator, The one provided with a transport screw as a developer transport member that transports in a direction opposite to the direction transported by the fins is used,
The lateral stirring of the developer is performed by the fins and the conveying screw.

Further, as in the developing device disclosed in Japanese Patent Application Laid-Open No. 61-156075, a multi-stage separator is provided,
There has also been proposed one in which lateral stirring is performed by changing the skew angle of each fin. However, in a developing device that performs lateral stirring with the above-described structure, if the developing device is displaced horizontally or the fluidity of the developer fluctuates due to a change in toner concentration or environment, the developer is moved in the axial direction of the developing carrier. It causes bias. Such bias of the developer causes problems such as deviation of toner concentration control, scattering of toner, and drop of developer.

On the other hand, in the developing device disclosed in Japanese Patent No. 02827438, a part of the fin is disposed on the separator at a different angle, and a part of the developer is moved in the axial direction of the developer carrier. By obliquely moving the developer in the opposite direction, the bias of the developer in one direction is eliminated.

[0006]

However, since this method is applied only when the direction of bias of the developer is always the same, it largely depends on the characteristics of the apparatus.

In view of the above problems, the present invention provides a developing device which spontaneously adjusts the amount of developer transported and keeps the balance of the amount of developer constant irrespective of the direction of bias of the developer. As an issue.

[0008]

According to a first aspect of the present invention, there is provided a developer carrier for conveying a developer to develop a latent image formed on the latent image carrier. When,
A developer container for storing a developer to be supplied to the developer carrier; a developer supply member for stirring the supplied toner and developer to supply the developer in the developer container to the developer carrier; A developer regulating member for setting the thickness of the developer on the developer carrying member to a thickness suitable for development; and the developer scraped by the developer regulating member flowing down to a location distant from the developer carrying member. A developer flowing member, a skew member for causing the developer to skew in a direction perpendicular to the axial direction of the developer carrier, and a developer on the developer flowing member. And a developer carrying member for receiving the part of the developer and transporting the developer in the direction of the rotation axis of the developer carrying member. A member for adjusting the amount of developer flowing into the skew member according to the deviation of the amount of the developer. And in which the developing device.
The invention according to claim 2 is the developing device according to claim 1, wherein the skew member is a plate-shaped member having a rotation axis in a direction perpendicular to an axis of the developer carrier. I do. The invention according to claim 3 is the developing device according to claim 1, wherein the skew member is a rod-shaped member having a rotation axis in a direction perpendicular to an axis of the developer carrier. .

According to a fourth aspect of the present invention, there is provided a developer carrier for conveying a developer to develop a latent image formed on the latent image carrier, and a developer for supplying the developer to the developer carrier. A developer container for storing the developer, a developer supply member for stirring the replenished toner and the developer, and supplying the developer in the developer container to the developer carrier; and a developer on the developer carrier. A developer regulating member for setting a thickness suitable for development, a developer flowing-down member for flowing the developer scraped off by the developer regulating member to a location distant from the developer carrying member, A skew member for skewing the developer in a direction perpendicular to the axial direction of the developer carrier, and receiving a part of the developer on the developer flow-down member; A developer transporting member that transports the developer in the rotation axis direction of the developer carrier. A developing device having a member for adjusting the amount of the developer flowing down according to the bias of the amount of the developer before the developer flowing into the skew member flows down from the developer flowing down member; and I do. According to a fifth aspect of the present invention, in the developing device according to the fourth aspect, the skew member is a plate-shaped member having a rotation axis perpendicular to an axis of the developer carrier. I do. The invention according to claim 6 is the developing device according to claim 4, wherein the skew member is a rod-shaped member having a rotation axis in a direction perpendicular to an axis of the developer carrying member. .

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a developing device according to the present invention. The developing device 2 includes a developing container 2a
And a toner replenishing section 2b. Of which
In the developing container 2a, a developing roller 3 as a developer carrying member is disposed so as to be close to the photosensitive drum 1 as a latent image carrying member, and a developing region is formed in a portion opposed to the both. It has become. A doctor blade 4 that regulates the amount of the developer is provided on the upstream side of the developing area in the developer transport direction. Further, the developing roller 3
The stirring roller 5 and the paddle wheel 6
The developer mixed and stirred by the stirring roller 5 is pumped up by the paddle wheel 6. Further, a developer case 21 as a developer accommodating member is disposed on the lower side so as to surround the developing roller 3, the paddle wheel 6, and the stirring roller 5. Also,
The toner replenishing unit 2b, for example, detects that the density of the toner supplied to the photosensitive drum
Is detected, the rotation of the toner supply roller 22 causes
The toner T is fed to the stirring roller 5. And in the vicinity of the doctor blade 4 described above,
Position one end in the extension direction near the doctor blade 4,
Separators 8 each having the other end in the extension direction positioned above the stirring roller 5 are arranged, and a rotatable conveyance screw 9 is arranged at the other end in the extension direction of the separator 8.

In the developing container 2 a having such a configuration, the developer is pumped up by the rotation of the paddle wheel 6, discharged toward the developing roller 3, and carried on the surface of the developing roller 3. The layer thickness of the developer carried on the developing roller 3 and moved with the rotation is regulated by the doctor blade 4. Excess developer scraped off by the doctor blade 4 is sequentially conveyed to the inner side of the image forming apparatus by a plurality of inclined fins 81 arranged on the separator 8.

FIG. 2 is a top view of the separator. A developer guide path is disposed at the innermost end of the separator 8 and is guided toward a transport screw 9 located at the other end in the extension direction, and is transported by the transport screw 9 to the front side of the image forming apparatus in the opposite direction to the above. It is conveyed through a path 82 and falls through a slit 83 facing the stirring roller 5 arranged at the forefront end. Before and after this, by transporting each developer,
The stirring is performed so that the toner concentration becomes uniform in the front-rear direction of the image forming apparatus. FIG. 3 is a perspective view of the separator showing the first embodiment. As a means for solving the above-mentioned problem, a balancer 84 is provided before the developer flows into the fins 81 so as to be able to incline according to the bias of the amount of the developer. It is characterized in that the amount of inflow is adjusted. The shape of the balancer 84 is, for example, a plate-like balancer 84a as shown in FIG.

Next, the operation of the balancer and the flow of the developer according to the bias of the amount of the developer will be described. In FIG. 3A, when the developer is biased to the F side, the separator 8
The amount of developer pumped up is also biased toward the F side,
This bias also causes a bias in the force with which the developer presses the balancer 84, in which case the developer is inclined in the direction of α. As a result, the amount of the developer flowing on the separator 8 is large on the F side and R
Side, the relationship between the amount MA of the developer conveyed to the R side by the fin 81 and the amount MB of the developer conveyed to the F side by the conveying screw 9 is MA> MB, and The biased developer is returned to the R side. Conversely, when the developer is biased toward the R side, the balancer 84 tilts in the direction of β, and the flow rate of the developer to the transport screw 9 increases, so that MA <MB. As a result, the balance of the amount of the developer is maintained.

The shape of the balancer 84 is shown in FIG.
Alternatively, a rod-shaped balancer 84b as shown in FIG. By making the shape of the balancer 84 rod-shaped, the durability against pressure from the developer can be increased as compared with the plate-shaped balancer 84b.

FIG. 4 is a top view of the separator according to the second embodiment. In the present embodiment, the balancer 85
Is provided on the side where the developer flows down from the fins 81. Balancer 85 according to the amount of developer
Is the same as that of the first embodiment, but the amount of the developer is adjusted just before flowing down from the separator 8 through the fins 81. The effect obtained is the same as in the first embodiment. The shape of the balancer 85 may be a plate-like balancer 85a shown in FIG. 4B or a rod-like balancer 85b shown in FIG. 4C. By making the shape of the balancer rod-shaped, durability against pressure from the developer can be increased.

[0016]

As described above, according to the present invention, when the developer existing in the axial direction of the developer carrier flows on the separator, the developer is moved in the axial direction of the developer carrier by the balancer. Since the transport amount is adjusted, it is possible to provide a developing device capable of keeping the balance of the amount of the developer constant.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a developing device according to the present invention.

FIG. 2 is a top view of a separator.

3A is a perspective view of a separator according to the first embodiment, FIG. 3B is a view illustrating a shape of a plate-shaped balancer, and FIG. 3C is a view illustrating a shape of a rod-shaped balancer; It is.

FIG. 4 is a top view of a separator showing a second embodiment, and FIG. 4 (b) is a view showing a shape of a plate-like balancer;
(C) is a figure which shows the shape of a rod-shaped balancer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photosensitive drum 2 developing device 2a developing container 2b toner replenishing section 21 developer case 22 toner replenishing roller 3 developing roller 4 doctor blade 5 stirring roller 6 paddle wheel 7 toner density sensor 8 separator 81 fin 82 transport path 83 slit 84 balancer 84a Plate-shaped balancer 84b Rod-shaped balancer 85 Balancer 85a Plate-shaped balancer 85b Rod-shaped balancer 9 Conveyor screw T Toner

Claims (6)

[Claims] 1. A developer carrier for transporting a developer to develop a latent image formed on a latent image carrier, a developing container containing a developer for supplying the developer carrier to the developer carrier, A developer supply member for stirring the replenished toner and the developer and supplying the developer in the developing container to the developer carrier; and setting the developer on the developer carrier to a thickness suitable for development. A developer regulating member, a developer flowing-down member that causes the developer scraped by the developer regulating member to flow down to a location distant from the developer carrier, A skew member for skewing in a direction orthogonal to the axial direction of the developer receiving portion of the developer on the developer flowing-down member, and moving the developer in a direction of the rotation axis of the developer carrier. And a developer conveying member for conveying the developer to the skew feeding member. Before, a developing device according to deviation of the amount of the developer, the developer is characterized in that it comprises a member for adjusting the amount flowing into the member for the oblique. 2. The developing device according to claim 1, wherein the skew member is a plate-shaped member having a rotation axis perpendicular to an axis of the developer carrier. . 3. The developing device according to claim 1, wherein the skew member is a rod-shaped member having a rotation axis perpendicular to an axis of the developer carrier. 4. A developer carrier for transporting a developer to develop a latent image formed on the latent image carrier, a developer container containing a developer for supplying the developer carrier to the developer carrier, A developer supply member for stirring the supplied toner and the developer to supply the developer in the developer container to the developer carrier, and setting the developer on the developer carrier to a thickness suitable for development. A developer regulating member; a developer flowing-down member for causing the developer scraped off by the developer regulating member to flow down to a location distant from the developer carrying member; A skew member for skewing in a direction orthogonal to the axial direction; and a part of the developer on the developer flow-down member, receiving the developer and moving the developer in the direction of the rotation axis of the developer carrier. A developer conveying member for conveying the developer, wherein the developer flowing into the skew feeding member is Before flowing down from the developer flows down member, in response to the deviation of the amount of the developer, developing apparatus is characterized in that it comprises a member for adjusting the amount of the developer flowing down. 5. The developing device according to claim 4, wherein the skew member is a plate-shaped member having a rotation axis perpendicular to an axis of the developer carrier. . 6. The developing device according to claim 4, wherein said skew member is a rod-shaped member having a rotation axis in a direction perpendicular to an axis of said developer carrier.