JP2999590B2 - Developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device in an image forming apparatus such as an electrophotographic copying machine, an electrostatic recording machine, and a magnetic recording machine, and more particularly to a developing device having an improved developer sealing function.

[0002]

2. Description of the Related Art Conventionally, various apparatuses have been proposed as dry one-component developing apparatuses using a dry non-magnetic one-component developer, and these apparatuses have been put into practical use. The configuration is as shown. That is, a supply / peeling roller 4 serving as a developer supply / peeling means is provided on the developing sleeve 2 serving as a developer carrier so as to rub inside the hopper 1 serving as a developer container. Developer 3
And the developer 3 remaining undeveloped on the developing sleeve 2 is peeled off. Further, an elastic blade 8 is disposed downstream of the rubbing portion between the supply / peeling roller 4 and the developing sleeve 2 in the rotation direction of the developing sleeve 2 so as to contact the surface of the developing sleeve 2. . The elastic blade 8 forms the developer 3 supplied onto the developing sleeve 2 by the supply / peeling roller 4 into a uniform thin layer at an abutting portion thereof, and reduces the amount of the developer to a necessary charge amount during development. 3 is charged.

Further, in the above-described conventional apparatus, end seal members 10 are attached to both ends of the developing sleeve 2 to prevent developer leakage. In particular, when a non-magnetic one-component developer is used, it cannot be restrained by magnetic force unlike a magnetic developer, and thus, prevention of developer leakage is an important issue. FIG. 9 is a view showing an example of a conventional sealing method, in which an elastic blade 8 is provided at an end of a developer application area formed with a width wider than an image area.
The sealing is performed by bringing the end face of the end seal member 10 into contact with the end face.

However, in such a sealing method, the width of the elastic blade 8 or the end sealing member 10 or the mounting position of the elastic blade 8 varies in manufacturing, so that the elastic blade 8 and the end In some cases, the seal member 10 could not be brought into close contact with the seal member 10, and a slight gap was sometimes formed between the two. as a result,
There is a problem that the developer 3 leaks as the developing sleeve 2 rotates.

Therefore, as shown in FIG. 10, the end of the end seal member 10 on the elastic blade 8 side is extended, and the extended portion is pushed from the back side of the elastic blade 8 (the side not in contact with the developing sleeve surface). The end seal member 10
Has been proposed to make the elastic blade 8 adhere to the elastic blade 8.

[0006]

However, according to the above-mentioned conventional example, the portion of the elastic blade 8 pressed from the back side by the end seal member 10 has a higher contact pressure with the developing sleeve 2 than the other portions. Therefore, when used for a long period of time, an aggregate of the developer 3 may be formed in the portion. As a result, there is a problem in that the agglomerates clog the contact portion between the elastic blade 8 and the developing sleeve 2 and hinder the formation of a thin layer of the developer on the developing sleeve 2.

SUMMARY OF THE INVENTION The present invention solves the above-described problems, and does not generate agglomerates of the developer. Further, the developing device can surely perform sealing even if there is a variation in manufacturing and mounting of members. It is intended to provide.

[0008]

According to the present invention, an object of the present invention is to provide a developer container which is rotatably provided at an opening of a developer container.
Agent and a developer carrying member for carrying conveyed to the developer carrying member
An elastic blade that regulates the thickness of the developer to be carried ;
Serial elastic blade, the developer container inner wall, and the and the end seal member for sealing a gap at the end of the opening formed between the developer carrying member, said developer carrying in the developer container current and a developer supply stripping means arranged to rub the body surface performs the peeling of the developer from the supply and the developer carrying member of a developing agent to said present <br/> image carrying member < In the image forming apparatus, the developer supply / peeler is configured to contribute to image formation in a longitudinal direction of the developer carrier.
Uniformly abut against the non-image area of the ends of the developer carrying member which does not contribute to the image area and the image forming of the image-carrying member
And the device is provided with the non-contact portion of the developer carrier.
End surface of the developer supply / separation unit that rubs against the image area
This is achieved by having a developer peeling means for removing the developer from the developer .

[0009]

According to the present invention, the developer is supplied to the developer carrier by the developer supply / peeling means, but the developer in the non-image areas at both ends of the developer carrier which does not contribute to image formation is: Since the toner is removed by the developer stripping means, the toner is supplied in a smaller amount than the image area in the middle part. Therefore,
The amount of the developer around the non-image area or the end seal member disposed further on the end side than the non-image area is reduced, and the sealing is reliably performed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and reference examples of the present invention will be described with reference to the drawings.

<First Embodiment> First, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2
1A and 1B are a cross-sectional view and a plan view of an apparatus according to a first embodiment in which the present invention is applied to a dry non-magnetic one-component developing apparatus. In FIG. 1, reference numeral 1 denotes a hopper as a developer container. At the opening of the hopper 1, a developing sleeve 2 as a developer carrier is rotatably supported, and is driven to rotate in the direction of arrow B by a driving source (not shown). The developing sleeve 2 is made of a non-magnetic material such as aluminum or stainless steel. The developing sleeve 2 carries a frictionally charged developer 3, which is a one-component non-magnetic developer in the hopper 1, on its surface by electrostatic attraction. ing.

A supply / peeling roller 4 serving as a developer supply / peeling means is provided below the developing sleeve 2 so as to slidably rotate at a rubbing portion S. The supply / peeling roller 4 is formed of an elastic body, and rotates in the same direction as the developing sleeve 2 so as to transfer the developer 3 to the developing sleeve 2.
The developer on the developing sleeve 2 is peeled off by being supplied to the developing sleeve 2 and making elastic contact with the developing sleeve 2. The developer application area where the developer is supplied and peeled by the supply / peeling roller 4 is formed to be wider in both ends of the developing sleeve 2 than the image area as shown in FIG. In the vicinity of both ends of the supply / peeling roller 4 corresponding to the non-image area, a scraper blade 5 as a developer peeling means for the supply / peeling roller 4 is disposed so as to abut.

The scraper blade 5 has one end attached to the supporting member 6 and the other end made to abut on the surface of the supply / peeling roller 4 at the abutment portion U with the free end. The contact portion U is located upstream of the developing sleeve 2 and the rubbing portion S of the supply / peeling roller 4 in the rotation direction of the supply / peeling roller 4. The developer 3 in the area corresponding to the non-image area is peeled off, and the developer 3 is dropped into the developer storage section of the hopper 1.

In the developer accommodating section behind the supply / peeling roller 4 for accommodating the developer 3 peeled off by the scraper blade 5, a developer feed member 7 is disposed so as to rotate in the direction of arrow D. Then, the developer 3 is supplied to the supply / peeling roller 4. However, since the developer 3 at both ends is separated by the scraper blade 5,
On the supply / peeling roller 4, the developer 3 is held only in the area corresponding to the image area shown in FIG. 2, and the developer 3 hardly exists in the area corresponding to the non-image area.

On the other hand, a free end of an elastic blade 8 is in contact with the developing sleeve 2 downstream of the rubbing portion S between the supply / peeling roller 4 and the developing sleeve 2 in the rotation direction of the developing sleeve 2. It is arranged so as to abut at the part T,
At the corresponding contact portion T, the passage of the developer 3 on the developing sleeve 2 is regulated. The elastic blade 8 is preferably made of a material of a triboelectric series suitable for charging the developer 3 to a desired polarity. For example, nylon, polyurethane, styrene-butadiene, or the like may be used to negatively charge a developer containing polyester as a component. By using the above materials, the triboelectric charging efficiency of the developer can be further increased.

A seal member 9 for closing a gap between the developing sleeve 2 and the opening of the hopper 1 is provided below the developing sleeve 2. The seal member 9 is formed of a flexible sheet such as Mylar (trade name, manufactured by DuPont),
In a bent state, one end portion comes into contact with the lower surface of the developing sleeve 2.

As described above, the end sealing members 10 are disposed at both ends of the developing sleeve 2 in which the elastic blade 8 is in contact with the upper portion and the sealing member 9 is in contact with the lower portion. Prevents leaks. The end sealing member 1
Numeral 0 is formed of an elastic member so as to be in sliding contact with the surface of the developing sleeve 2 protruding into the hopper 1 in the circumferential direction. The end seal member 10 is provided with the developing sleeve 2.
In the longitudinal direction of FIG. 9, the side end face of the end seal member 10 is disposed outside the developer application area at a boundary position with the developer application area as in the conventional example shown in FIG. 9. And the elastic blade 8 and the side end surface of the seal member 9 are in contact with each other.

In the developing device as described above, when the developer feed member 7 shown in FIG. 1 supplies the developer 3 to the supply / peeling roller 4 by rotation in the direction of arrow D, the developer 3 The supply / peeling roller 4 is carried by the peeling roller 4 over the entire area in the longitudinal direction. The carried developer 3 is conveyed to the rubbing portion S with the developing sleeve 2 by the rotation of the supply / peeling roller 4 in the direction of arrow C. At this time, the developer 3 is carried by the supply / peeling roller 4. The developer 3 carried on the non-image area is peeled off at the contact portion U of the scraper blade 5. Therefore, in the rubbing section S, the developer 3 is supplied only to the image area, and is not supplied to the non-image area.

The developer 3 in the image area which has been frictionally charged by being rubbed with the developing sleeve 2 at the rubbing portion S is brought into contact with the elastic blade 8 by the rotation of the developing sleeve 2 in the direction of arrow B. While being conveyed, when passing through the contact portion T between the elastic blade 8 and the developing sleeve 2, the surface of the developing sleeve 2 is rubbed and rubbed by the elastic blade 8 and further receives triboelectric charging. In this manner, the developer 3 can receive sufficient triboelectric charging.

The developer 3 which has been sufficiently triboelectrically charged passes through the contact portion T and is formed as a thin layer of the developer on the developing sleeve 2, and the developing sleeve 2 is contacted with a photosensitive drum (not shown). It is transported to the opposite developing section. Further, the contact portion T
Most of the developer 3 passing through the image region exists in the image region as described above, and very little exists in the non-image region.
Accordingly, the amount of the developer around the end seal member 10 is also reduced, so that the sealing operation is reliably performed.

On the other hand, in the developing section, a part of the developer is consumed by the developing operation, and the other developer is recovered from the lower part of the developing sleeve 2 with the rotation of the developing sleeve 2. A seal member 9 is provided at the collection portion to allow the developer not consumed in the development to pass through the hopper 1 and
This prevents the developer 3 in the hopper 1 from leaking from the lower part of the hopper 1. The collected developer on the developing sleeve 2 is supplied to and rubbed between the supply / peeling roller 4 and the developing sleeve 2.
And is scraped off by elastic contact. The scraped developer 3 merges with the developer 3 transported by the toner feeding member 7 and is transported to the rubbing portion S again as described above.

As described above, according to the present embodiment, the area where the developer 3 is present on the developing sleeve 2 can be limited to the image area, and the amount of the developer around the end seal member 10 can be significantly reduced. Even when the conventional sealing method shown in FIG. 9 is used, a reliable sealing operation can be realized without affecting the image. Therefore, it is possible to stably form a thin layer of the developer by the elastic blade 8 without generating the aggregate of the developer as in the related art. Further, even if there is some variation in manufacturing or mounting of the members, the sealing operation can be reliably performed because the developer around the end seal member 10 is extremely small as described above.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description is omitted.

FIG. 3 is a sectional view showing a schematic configuration of this embodiment.
FIG. 4 is a plan view thereof. This embodiment is different from the first embodiment in that a scraper roller 11 is used instead of the scraper blade 5 as shown in FIGS.

[0025] The scraper blade may be chipped at the edge as the endurance progresses, or the developer may be fused at the edge portion, resulting in defective scraping. However, according to the present embodiment, it is possible to always and stably scrape the developer in the area corresponding to the non-image area on the supply / peeling roller 4 without causing a scraping defect even when used for a long time. it can. As a result, a high sealing effect can be maintained.

[0026] <First Example> The following describes a first reference example of the context of the present invention with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description is omitted.

The present embodiment, as shown in FIG. 5, without providing a scraper blade 5, the central portion of the outer diameter, corresponding to the image regions in both end portions corresponding to the non-image area of the feed-stripping roller 4 Is different from the first embodiment in that the outer diameter is smaller than that of the first embodiment.

Since the amount of the developer applied to the developing sleeve 2 depends on the pressure between the developing sleeve 2 and the supply / peeling roller 4 and the nip width, it corresponds to the non-image area as in this embodiment. If the outer diameter of the area to be reduced is reduced, the pressure and the nip width are reduced, and the amount of the developer applied to the non-image area can be reduced. Therefore, the amount of the developer around the end seal member can be reduced, and a reliable sealing operation can be realized.

[0029] <Second Example> Next, a second reference example of regarding the present invention will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description is omitted.

The present embodiment, as shown in FIG. 6, different from the central portion to the corresponding process such as the material itself or its surface at both the end portions corresponding to the non-image area of the feed-stripping roller 4 in the image area This is different from the first embodiment. In addition, similarly to the first reference example, the scraper blade 5
Is not provided.

For example, when a foam is used for the supply / peeling roller 4, the number of cells per unit volume at both ends (hereinafter referred to as the number of cells) is made smaller than that at the center. As a result, the supply amount of the developer to the developing sleeve 2 is smaller than that in the central portion where the number of cells per unit volume is large. The same effect as described above is produced. Further, since the developer is rubbed and frictionally charged between the developing sleeve 2 and the supply / peeling roller 4, and is applied to the developing sleeve 2 by electrostatic attraction, the material of the foam at both ends is used. May be made of a material to which little charge is applied by frictional charging to the developer. Furthermore, the surface of only the foams at both ends may be melted by heat to lower the developer application performance.

< Third Reference Example> Next, a third reference example will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description is omitted.

The present embodiment, as shown in FIG. 7, the both end portions of the feed-stripping roller 4 corresponding to the non-image area, the shaft 1
This embodiment is different from the first embodiment in that it is configured as a separate member 13 rotatable around 2. The member 13 includes an inner bearing portion 14.
And an outer peripheral foam 15.

The central portion of the supply / peeling roller 4 corresponding to the image area is rotated by the shaft 12 in the counter direction, which is the same direction as the rotation direction of the developing sleeve 2, but the member 13 is in contact with the developing sleeve 2. It is driven and rotated by contact. Therefore, the amount of developer supplied to the non-image area of the developing sleeve 2 is reduced without frictionally charging or rubbing the developer. Actions can be taken.

[0035]

As described above, according to the present invention,
Developer supply stripping means, the developer peeling means a developer to the non-image areas of both end portions of the developer carrying member which does not contribute to image formation
And the amount of developer around the end seal member is reduced, and the end surface of the end seal member is brought into close contact with the end surface of the surrounding member. Even in the case of a simple configuration, a reliable sealing operation can be performed, and no aggregate of the developer is generated. Further, even if there is some variation in manufacturing or mounting of the member, a sufficient sealing effect can be exhibited.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic configuration of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view of the apparatus in FIG. 1;

FIG. 3 is a cross-sectional view illustrating a schematic configuration of a device according to a second embodiment of the present invention.

FIG. 4 is a plan view of the device in FIG. 3;

FIGS. 5A and 5B are a plan view and a front view of a developer supply / peeling unit in a first reference example relating to the present invention.

FIG. 6 is a plan view and a front view of a developer supply / peeling unit according to a second reference example.

FIG. 7 is a plan view and a perspective view of a developer supply / peeling unit in a third reference example of the present invention.

FIG. 8 is a cross-sectional view illustrating a schematic configuration of a conventional device.

FIG. 9 is a cross-sectional view for explaining a sealing method in a conventional device.

FIG. 10 is a cross-sectional view for explaining another sealing method in the conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Developer container (hopper) 2 Developer carrier (development sleeve) 3 Developer 4 Developer supply / peeler (supply / peeling roller) 8 Elastic blade 10 End seal member

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-246769 (JP, A) JP-A-63-172291 (JP, A) JP-A-2-251873 (JP, A) JP-A-4- 174470 (JP, A) JP-A-5-35069 (JP, A) JP-A-64-26876 (JP, A) JP-A-64-49066 (JP, A) JP-A-58-34468 (JP, A) JP-A-58-37674 (JP, A) JP-A-63-210974 (JP, A) JP-A-63-304278 (JP, A) Fully open Showa 62-137451 (JP, U) Fully open flat 3-112760 (JP, U) Japanese Utility Model 2-53050 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 15/08-15/095

Claims (1)

(57) [Claims] 1. A developer container rotatably provided at an opening of a developer container .
Is, a developer carrying member for bearing and conveying the developer, an elastic blade for regulating the thickness of the developer carried on said developer carrying member, the elastic blade, the developer container inner wall, and the upper <br / > Symbol rubbing and end seal member for sealing the <br/> definitive gap end of the opening that is formed, and the surface of the developer carrying member in the developing agent container between the developer carrying member Set to be
Re and a developer supplying peeling means for performing the release of the developer from the supply and the developer carrying member of a developing agent to the developing agent carrier
In the developing device having the developer supply and peeling means,
It contributes to image formation in the longitudinal direction of the developer carrier .
That uniformly against the non-image area of the ends of the developer carrying member which does not contribute to the image area and the image formation of the developer carrying member
The device is provided so as to be in contact with the developer carrying member.
Of the developer supply / peeler that rubs against the non-image area of
Has a developer stripping means for removing the developer from the end surface
A developing device , characterized in that: