JP4862430B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  As shown in FIG. 8, a conventional image forming apparatus using an electrophotographic image forming system such as a copying machine or a printer supplies a developer (toner) T to a rotating drum-shaped photosensitive member 21 by a developing unit 22. To form an image. The developing device 22 contains a developing roller 24 that carries the toner T by rotation thereof in a housing 23. Further, in the housing 23, in order to prevent the toner T from leaking to the outside, the photosensitive member contact seal 25 that contacts the photosensitive member 21, and the photosensitive member contact seal auxiliary that prevents the photosensitive member contact seal 25 from falling or undulating. The member 26 is stuck on and overlapped with an adhesive 27.

  Further, as shown in FIG. 9, the housing 23 of the developing unit 22 includes an end photosensitive member sliding contact seal 28 that is in sliding contact with the end portion of the photosensitive member 21, and a photosensitive member from behind the end photosensitive member sliding contact seal 28. And an end elastic seal 29 that abuts on the end of 21.

  In assembling the developing device 22, the end elastic seal 29 is first attached to the housing 23, and the end photoconductor sliding seal 28 is attached so as to be in close contact with the end of the end elastic seal 29. Then, the photoconductor contact seal auxiliary member 26 is attached so that the end portion thereof overlaps the end photoconductor sliding seal 28, and the photoconductor contact seal 25 is overlaid on the photoconductor contact seal auxiliary member 26. To wear.

  Further, FIG. 10 shows a cross section of the overlapping portion of the photoconductor contact seal 25 and the end photoconductor slide seal 28. The thicknesses of the photosensitive member contact seal 25, the photosensitive member contact seal auxiliary member 26, the end photosensitive member sliding contact seal 28, and the adhesive 27 cause a gap g at each upper end portion (downstream in the rotation direction of the developing roller 24). . The toner T enters these gaps g.

  The photoconductor contact seal 25, the photoconductor contact seal auxiliary member 26, the end photoconductor sliding contact seal 28, and the adhesive 27 are not only on the upper ends of the photoconductor contact seal 25, the photoconductor contact seal auxiliary member 26, Also forms a similar gap g. For this reason, as indicated by a broken line arrow in FIG. 11, the toner T passes through the gap g and leaks from the developing unit 22 to the space upstream in the rotation direction of the photosensitive member 21.

  When the toner T leaked to the upstream side of the photosensitive member 21 adheres to a functional component such as a charger, it causes density unevenness of the image to be formed, carrier adhesion, and the like.

A member corresponding to the end photoconductor sliding seal 28 in the above configuration is described in Patent Document 1, and a member corresponding to the photoconductor contact seal 25 is described in Patent Document 2.

JP-A-58-182626 JP-A 64-584

  In view of the above problems, an object of the present invention is to provide an image forming apparatus having a high sealing ability between a developing device and a photoreceptor.

In order to solve the above problems, a first aspect of an image forming apparatus according to the present invention includes a rotating drum-type photoconductor and a developing device that supplies a developer to the photoconductor, and the developing device includes: A housing for housing the developer, and a belt-like shape that is fixed to the housing and seals a gap between the housing and the photoconductor in contact with the photoconductor on the upstream side in the rotation direction of the developing area of the photoconductor And a sheet-like photoreceptor contact seal, and a belt- like photoreceptor contact seal that is interposed between the photoreceptor contact seal and the housing to support the photoreceptor contact seal and protrudes from the housing toward the photoreceptor. An auxiliary photoconductor and an end photoconductor sliding seal that extends from both ends of the photoconductor contact seal auxiliary to the downstream side in the rotation direction of the photoconductor and contacts the photoconductor outside both sides of the development region Rannahli, the photosensitive member contact seal adhered sheets form sealing and an auxiliary member, is fixed to the housing, wherein on either side outside of the developing area of the photosensitive member, abutting end elastic sealing said photoconductor The photoconductor contact seal protrudes further toward the photoconductor side than the photoconductor contact seal auxiliary portion .

  According to this configuration, the photoconductor contact seal auxiliary member that supports the photoconductor contact seal that contacts the upstream side of the development area of the photoconductor and the end photoconductor sliding seal that contacts the outside of the photoconductor development area are integrated. Therefore, there is no gap between the photoconductor contact seal auxiliary portion and the end photoconductor sliding seal portion. For this reason, there are few paths through which toner leaks, and the sealing ability between the developing unit and the photosensitive member is high.

According to a second aspect of the image forming apparatus of the present invention, the image forming apparatus includes a rotating drum-type photosensitive member and a developing unit that supplies a developer to the photosensitive member, and the developing unit contains the developer. And a belt-shaped photoreceptor contact seal that is fixed to the housing and contacts the photoreceptor and seals a gap between the housing and the photoreceptor on the upstream side in the rotation direction of the developing area of the photoreceptor. A belt-like photosensitive member contact seal auxiliary part interposed between the photosensitive member contact seal and the housing and supporting the photosensitive member contact seal, and a rotation direction of the photosensitive member from both ends of the photosensitive member contact seal auxiliary part A seal and auxiliary member comprising an end photoconductor sliding seal portion that extends downstream and contacts the photoconductor outside both sides of the development area, and is fixed to the housing, and the development area of the photoconductor In both sides outside the the photoreceptor comprising an end elastic sealing contact with, said end elastic sealing, the photosensitive member contact seal and the sealing and the auxiliary member partially overlap, outside of the end elastic sealing These end portions are arranged outside the end portions of the photoconductor contact seal and the seal / auxiliary member.

  According to this configuration, the end portion elastic seal seals both side ends of the photoconductor contact seal and the seal / auxiliary member, so that it is difficult for the developer to leak out.

  In the image forming apparatus of the present invention, both side ends of the photoconductor contact seal may coincide with both end portions of the seal / auxiliary member, or may be located outside both end portions of the seal / auxiliary member.

  According to this configuration, since no gap is generated between the photoreceptor contact seal and the seal / auxiliary member, the developer is difficult to leak out.

  As described above, according to the present invention, since the photosensitive member contact seal auxiliary member and the end photosensitive member sliding seal portion are integrally formed, the photosensitive member contact seal auxiliary portion, the end photosensitive member sliding seal portion, No gap is formed between them, and the developer is difficult to leak out.

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 shows a developing device 1 of an image forming apparatus according to an embodiment of the present invention. The developing device 1 contains toner T as a developer inside a housing 2, and the developing roller 3 is exposed from the opening of the housing 2. As shown in FIG. 2, the developing roller 3 faces the drum-shaped photosensitive member 4 rotating in the direction of arrow A, and rotates in the direction of arrow B to convey the toner T on the outer peripheral surface and supply it to the photosensitive member 4. As a result, an image is developed on the photoreceptor 4.

  Further, in the developing device 1, a strip-shaped photoconductor contact seal 5 is stuck on the housing 2 in order to prevent the toner T from leaking upstream in the rotation direction of the photoconductor 4. Since the upper end of the photoconductor contact seal 5 is in contact with the upstream side of the developing area (an area where an image is developed) of the photoconductor 4, for example, a polyurethane sheet having a thickness of 75 to 200 μm is used so as not to damage the photoconductor 4. Made of flexible material.

  Further, the developing device 1 includes a belt-shaped photoconductor contact seal auxiliary portion 6 interposed between the housing 2 and the photoconductor contact seal 5, and the rotation direction of the photoconductor 4 from both ends of the photoconductor contact seal auxiliary portion 6 (see FIG. 2 in the direction of arrow A) and has a seal and auxiliary member 8 composed of an end photosensitive member sliding seal portion 7 extending downstream. The photoreceptor contact seal 5 and the seal / auxiliary member 8 are stuck on the housing 2 so as to overlap with the adhesive 9. FIG. 1 shows only one end of the developing device 1, but the developing device 1 is bilaterally symmetric, and the seal and auxiliary member 8 is formed in a concave shape.

  The seal / auxiliary member 8 is made of a solid material, for example, 75 μm thick, so that the photoconductor contact seal auxiliary portion 6 can support the photoconductor contact seal 5 from the back side and prevent the photoconductor contact seal 5 from crushing and falling. It is formed of a polyethylene terephthalate (PET) sheet.

  As shown in FIG. 3, end elastic seals 10 are attached to the housing 2 on the side of the developing roller 3 to seal the gap between the housing 2 and the photoconductor 4 outside both sides of the developing region. It has stopped. The end elastic seal 10 is made of an elastic foam material such as polyurethane foam so that it can be deformed in accordance with the shape of the photoreceptor 4.

  The end elastic seal 10 overlaps both the seal / auxiliary member 8 and the photoconductor contact seal 5, but the outer end of the end elastic seal 10 is from the end of the seal / auxiliary member 8 and the photoconductor contact seal 5. Is also arranged on the outside.

FIG. 4 shows a state in which the developing device 1 is disassembled, and an assembling procedure thereof will be described.
First, the end elastic seals 10 are attached to both sides of the housing 2. Subsequently, the seal and auxiliary member 8 is attached to the upstream surface of the housing 2 with an adhesive 9. At this time, it is necessary that the end photoconductor sliding seal portion 7 is in close contact with the end surface of the end elastic seal 10 so that there is no gap. The photosensitive member contact seal auxiliary portion 6 is attached to the housing 2 only on the lower side so that the upper end protrudes from the housing 2. Further, the photosensitive member contact seal 5 is laminated on the seal / auxiliary member 8 with an adhesive 9 and attached. At this time, the upper end of the photoconductor contact seal 5 protrudes above the photoconductor contact seal auxiliary portion 6 so that the deformation of the photoconductor contact seal 5 is not hindered. 9 is not applied.

The operation of this embodiment will now be described.
The photoconductor contact seal 5 seals the gap between the housing 2 and the photoconductor 4 on the upstream side of the development area, and the end elastic seal 10 seals the gap between the housing 2 and the photoconductor 4 on both sides outside the development area. Stop. The end photoconductor sliding seal portion 7 covers the photoconductor 4 so that the toner T does not adhere to the outside of both sides of the development region.

  As shown in FIGS. 2 and 3, a gap g <b> 1 is formed between the photoconductor contact seal 5 and the photoconductor contact seal auxiliary portion 6 depending on the thickness of the adhesive 9. As shown in FIG. 3, a gap g <b> 2 is formed at the front end portion of the photoconductor contact seal 5 between the end photoconductor sliding seal portion 7 and the photoconductor 4 depending on the thickness of the photoconductor contact seal 5. Is done. Similarly, at both ends of the photoconductor contact seal 5, a gap extending in the rotation direction of the photoconductor 4 is formed between the seal / auxiliary member 8 and the photoconductor 4.

  However, in this embodiment, since the seal and auxiliary member 8 in which the photoconductor contact seal auxiliary portion 6 and the end photoconductor sliding seal portion 7 are integrally formed is used, the thickness of the photoconductor contact seal auxiliary portion 6 is used. Therefore, no gap is formed in the end photosensitive member sliding seal portion 7. Therefore, in the image forming apparatus of the present embodiment, the toner T is difficult to leak from the developing device 1 to the upstream side of the photosensitive member 4. As indicated by broken line arrows in FIG. 5, the toner T enters the gap g1 and the gap g2 and can slightly leak to the upstream side of the photoreceptor 4, but compared with the conventional configuration shown in FIG. The amount of leakage is slight.

  Next, FIG. 6 shows a developing device 1 ′ of the image forming apparatus according to the second embodiment of the present invention. In the description of the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  The photoreceptor contact seal 5 ′ of the present embodiment has the same length as the seal / auxiliary member 8, and the positions of both end portions coincide with the end portions of the seal / auxiliary member 8. Therefore, the end portions of the photoreceptor contact seal 5 ′ and the seal / auxiliary member 8 are covered with the end elastic seal 10 having excellent deformability and do not form a gap. For this reason, as shown in FIG. 7, the toner T is pressed against the photoconductor 4 by the end elastic seal 10 even if it leaks laterally from the gaps g1 and g2. To the downstream side, and does not leak to the upstream side.

  In this embodiment, the photoreceptor contact seal 5 ′ has the same length as the seal / auxiliary member 8, but is longer than the seal / auxiliary member 8, and both ends thereof are disposed outside the seal / auxiliary member 8. However, the end portions of the photoreceptor contact seal 5 ′ and the seal and auxiliary member 8 are covered with the end elastic seal 10, so that the toner T does not leak to the upstream side of the photoreceptor 4.

FIG. 2 is a partial perspective view of a developing device of the image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a partial cross-sectional view at the center of a developing device of the image forming apparatus of FIG. 1. FIG. 2 is a partial cross-sectional view at a middle end of a developing device of the image forming apparatus of FIG. 1. FIG. 2 is an exploded perspective view of the developing device in FIG. 1. FIG. 2 is a schematic diagram illustrating a toner leakage path in the image forming apparatus of FIG. 1. FIG. 9 is a partial perspective view of a developing device of an image forming apparatus according to a second embodiment of the present invention. FIG. 7 is a schematic diagram illustrating a toner leakage path in the image forming apparatus of FIG. 6. FIG. 10 is a partial cross-sectional view of a conventional image forming apparatus. FIG. 9 is a partial perspective view of a developing device of the image forming apparatus in FIG. 8 . Cross-sectional view at different positions of the image forming apparatus of FIG. FIG. 9 is a schematic diagram illustrating a toner leakage path in the image forming apparatus of FIG. 8 .

DESCRIPTION OF SYMBOLS 1,1 'Developing device 2 Housing 3 Developing roller 4 Photoconductor 5,5' Photoconductor contact seal 6 Photoconductor contact seal auxiliary part 7 End photoconductor sliding seal part 8 Sealing / auxiliary member 9 Adhesive 10 End elastic sticker

Claims (3)

A rotating drum-type photoreceptor, and a developing device for supplying a developer to the photoreceptor,
The developing device includes a housing for accommodating the developer;
A belt- like and sheet-like photoconductor contact seal fixed to the housing and in contact with the photoconductor to seal a gap between the housing and the photoconductor on the upstream side in the rotation direction of the developing region of the photoconductor;
A belt-shaped photoconductor contact seal auxiliary portion that is interposed between the photoconductor contact seal and the housing to support the photoconductor contact seal and protrudes from the housing toward the photoconductor, and the photoconductor contact seal It consists of an end photoconductor sliding seal portion that extends from both ends of the auxiliary portion to the downstream side in the rotation direction of the photoconductor and contacts the photoconductor outside both sides of the development area, and is attached to the photoconductor contact seal. Sheet-like seal and auxiliary member,
An end elastic seal that is fixed to the housing and is in contact with the photoconductor outside both sides of the development area of the photoconductor;
The image forming apparatus according to claim 1, wherein the photoconductor contact seal protrudes further toward the photoconductor than the photoconductor contact seal auxiliary portion . A rotating drum-type photoreceptor, and a developing device for supplying a developer to the photoreceptor,
The developing device includes a housing for accommodating the developer;
A belt-shaped photoreceptor contact seal fixed to the housing and sealing the gap between the housing and the photoreceptor on the upstream side of the developing area of the photoreceptor in the rotational direction;
A belt-shaped photoconductor contact seal auxiliary portion that is interposed between the photoconductor contact seal and the housing and supports the photoconductor contact seal, and downstream of the photoconductor rotation direction from both ends of the photoconductor contact seal auxiliary portion. A seal and auxiliary member consisting of an end photoconductor sliding seal portion that extends to the side and contacts the photoconductor outside both sides of the development region;
An end elastic seal that is fixed to the housing and is in contact with the photoconductor outside both sides of the development area of the photoconductor;
The end elastic seal partially overlaps the photoconductor contact seal and the seal / auxiliary member, and an outer end of the end elastic seal is an end of the photoconductor contact seal and the seal / auxiliary member. An image forming apparatus, wherein the image forming apparatus is disposed on the outer side.   3. The image according to claim 1, wherein both end portions of the photoconductor contact seal coincide with both end portions of the seal / auxiliary member or are located outside both end portions of the seal / auxiliary member. 4. Forming equipment.

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