JP2006106306A - Developing apparatus, process cartridge and electronic photographic image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing apparatus capable of stabilizing a sealing property by improving the assemblability of an end part seal and eliminating dispersion of sticking. <P>SOLUTION: The developing apparatus comprises a developing case 16 having an aperture part 21 on one end and allowed to store developer, a developer carrier 18 rotatably supported on the aperture part 21 of the developer case 16 to hold and transport the developer to develop an electrostatic latent image formed on a photoreceptor 11 and the end part seal 22 for preventing the developer from being leaked from a gap generated between the developer case 16 arranged on the end part of a longitudinal direction of the developer carrier 18 and the developer carrier 18. The end part seal 22 is provided with a supporting part 22b having a circular arc shape part 22d formed on a surface 26 opposed to the developer carrier 18 along the developer carrier 18 and a seal part 22a consisting of transplanting feathers on the surface 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a developing device used in an electrophotographic image forming apparatus, a process cartridge that can be attached to and detached from a main body of the electrophotographic image forming apparatus, and an electrophotographic image forming apparatus.

  Here, the electrophotographic image forming apparatus forms an image on a recording medium (for example, paper, an OHP sheet) using an electrophotographic image forming process. For example, an electrophotographic copying machine, an electrophotographic printer (for example, an LED printer, a laser beam printer, etc.), an electrophotographic facsimile apparatus, an electrophotographic word processor, and the like are included.

  The process cartridge refers to a cartridge in which at least developing means (developing device) and an electrophotographic photosensitive member are integrated into a cartridge so as to be detachable from the main body of the electrophotographic image forming apparatus.

  2. Description of the Related Art Conventionally, an electrophotographic image forming apparatus employs a process cartridge system in which an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge can be attached to and detached from the image forming apparatus main body. According to this process cartridge system, maintenance of the apparatus can be performed by the user himself / herself without depending on the service person. Thereby, operability can be remarkably improved.

  The developing device in the form of a cartridge has a developer container having an opening at one end and containing a developer (hereinafter referred to as “toner”), and a developer that is rotatably disposed in the opening and conveys the toner to the photoreceptor. A carrier (hereinafter referred to as “developing roller”) and end seals for preventing toner leakage in the longitudinal direction of the developing roller at both ends in the longitudinal direction of the opening (see Patent Document 1). The developing container also serves as a cartridge frame.

JP 2000-131941 A (2nd page, Fig. 4)

  However, the seal portion of the end seal has a sheet shape. Therefore, it is necessary to have skill in the operation to attach the sheet-like seal member to the seal attachment seat surface of the developer container having a shape along the developing roller.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device with improved end seal assembly, a process cartridge using the developing device, and an electrophotographic image forming apparatus to which the process cartridge can be attached and detached.

  In order to solve the above-described problems, a typical configuration of a developing device according to the present invention is a developing device for developing an electrostatic latent image formed on an electrophotographic photosensitive member. A developing roller for developing a latent image, and a developer storage portion for storing the developer used for developing the electrostatic latent image by the developing roller, wherein the developer in the developer storage portion is developed. Produced between the developer frame having a developer supply opening for supplying to the roller and the cartridge frame and the developing roller disposed at one end and the other end in the longitudinal direction of the developing roller. An end seal that restricts the developer from leaking from the gap, and the end seal has an arc shape along a part of the peripheral surface of the developing roller on a surface facing the developing roller A support portion having a portion, and Characterized in that it comprises a seal portion subjected to flocking on the surface of the arc-shaped portion.

  According to the present invention, the assemblability of the end seal can be improved. Moreover, the variation in assembling the end seal could be reduced. Therefore, the sealing performance could be stabilized.

[First embodiment]
First, a process cartridge having a developing device will be described with reference to FIG. The process cartridge 15 shown in the drawing is provided with a photoconductor and process means acting on the photoconductor. Examples of the process means include a charging means for charging the surface of the photoreceptor, a developing device for developing an electrostatic latent image formed on the photoreceptor, and a cleaning means for removing toner remaining on the photoreceptor surface. .

  In the figure, a process cartridge 15 has a charging roller 12 as a charging means around a photosensitive drum 11 as a photosensitive member. The photosensitive drum 11 is generally obtained by vapor-depositing or coating a photoconductor on a cylinder made of aluminum alloy or the like. Examples of the photoconductor include amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, and organic photoconductor (OPC). Further, the developing device D includes a developing roller 18, a developing blade 19, and a developing container 16 as an example of a developer storage unit that stores toner. Further, a cleaning frame 13 and a cleaning blade 14 are disposed as cleaning means. These are covered with a housing to form a cartridge 15 which is detachable from the image forming apparatus main body C (see FIG. 2).

  The schematic configuration of the image forming apparatus will be described with reference to FIG. As shown in FIG. 2, the process cartridge 15 attached to the image forming apparatus C is used for image formation. In image formation, a sheet (recording medium) S is conveyed from a sheet cassette 6 mounted at the lower part of the apparatus by a conveying roller 7 as an example of a sheet conveying unit. In synchronization with this sheet conveyance, the photosensitive drum 11 is selectively exposed from the exposure device 8 to form an electrostatic latent image. Thereafter, the toner accommodated in the developing container 16 as the developer accommodating portion is carried on the surface of the developing roller 18 by a developing blade 19 as a thin layer. Then, a developing bias is applied to the developing roller 18. Thus, toner is supplied according to the latent image. This toner image is transferred to the sheet S conveyed by applying a bias voltage to the transfer roller 9. Thereafter, the sheet S is conveyed to the fixing device 1 to fix the image, and is discharged by the discharge roller 2 to the discharge unit 3 at the top of the device.

  The configuration of the end seal disposed at the end in the longitudinal direction of the developing roller 18 of the developing device D will be described with reference to FIGS. 3 and 4. FIG. 3 is a diagram illustrating the configuration of the end seal with the developing roller removed, and FIG. 4 is a partial cross-sectional explanatory diagram of the end seal.

  The developing device D includes a developing container 16 that stores toner, and a developing frame 17 (cartridge frame) that has a developer supply opening 21 and supports the developing roller 18 and the developing blade 19. At both ends of the opening 21, an end seal 22 that prevents toner leakage in the longitudinal direction of the developing roller 18 and between the developing roller 18 and the end seal 22 at the lower portion of the opening 21. And a flexible sheet member 23 that prevents the toner from blowing out from the gap. The flexible sheet member 23 is joined to the developing device frame 17 with a double-sided tape, an adhesive, or the like. That is, the developer container 16 stores the developer used for developing the electrostatic latent image by the developing roller 18. Further, a supply opening 21 for supplying the developer in the developing container 16 to the developing roller 18 is provided.

  Next, an end seal structure for preventing toner leakage in the longitudinal direction of the developing roller 18 will be described. The end seals 22 are disposed at both ends in the longitudinal direction of the developing roller 18 so as to contact the peripheral surface on the developing frame body 17 side and further to both ends of the developing blade 19 (that is, the developing roller 18 In the longitudinal direction, the developing blade 19 is set to a length that partially covers the end seal 22). In order to facilitate the close installation of the end seal 22 to the end of the developing blade 19, as shown in FIG. 4, the end seal 22 and the developing blade 19 overlap each other. That is, the developing blade 19 is disposed so as to cover the surface of the end seal 22 in a direction orthogonal to the longitudinal direction of the developing roller 18 and in the vertical direction in the figure. Then, at the overlapping portion, the end seal 22 is buried under the developing blade 19.

  The configuration of the end seal will be described with reference to FIG. FIG. 5 a is an explanatory view of the end seal 22, and FIG. 5 b is an explanatory view of the support portion 22 b before flocking the seal portion 22 a of the end seal 22.

  The end seal 22 has a support portion 22b and a seal portion 22a in which fuzz is arranged on the surface (surface 26) facing the developing roller 18 of the support portion 22b by electrostatic flocking. The support portion 22b has an arc-shaped portion 22d having a certain distance from the developing roller 18. The surface 26a of the arc-shaped portion 22d is connected to the surface 26b on the developing blade side and the surface 26c on the flexible sheet side from the surface 26a. The sealing portion 22a is flocked on the entire surface 26a. An adhesive layer for adhering the fuzz of the seal portion 22a is interposed between the seal portion 22a and the support portion 22b.

  Thus, the end seal 22 is disposed at one end and the other end of the developing roller 18 in the longitudinal direction. The end seal 22 restricts the developer from leaking from a gap formed between the developing container 16 and the developing roller 18.

  The end seal 22 has a support portion 22b having an arc-shaped portion 22d along a part of the peripheral surface of the developing roller 18 on a surface facing the developing roller 18, and a surface of the arc-shaped portion 22d. And a seal portion 22a to which flocking is applied. Since the support portion 22b has elasticity, the seal portion 22a is elastically pressed against a part of the peripheral surface of the developing roller by this elastic force. That is, the part to which the flock is applied contacts the peripheral surface of the developing roller. Accordingly, the leakage of the developer from the end portion of the developing roller can be prevented.

  As described above, in this embodiment, the seal portion 22a is implanted by electrostatic flocking. Electrostatic flocking uses electrostatic attraction in a high-voltage electrostatic field. The fluff fibers are held up by an electrostatic attraction force, and in that state, the hair is implanted in a portion to which an adhesive has been applied in advance. The fluff of the seal part 22a is preferably made of a material having slidability and wear resistance. For example, ultra high molecular polyethylene, polypropylene, polyamide, aramid resin, fluororesin and the like can be mentioned.

  Next, the relationship between the end seal 22, the developing device frame 17, and the developing container 16 will be described. As shown in FIG. 4, the end seal 22 is in contact with the developing device frame 17 or the developing container 16 except for the surface 26 and the inner side surface. Although the contact surface 22e of the end seal 22 against the developing device frame 17 or the developing container 16 is shown in close contact in FIG. 4, the developing device frame 17, the developing container 16, and the end seal supporting portion 22b are Since each has a component tolerance, a minute gap 25 is formed. Therefore, it is necessary to prevent the toner from leaking from the gap 25 between the developing frame 17, the developing container 16, and the end seal support 22b. Here, since the sealing method of the gap 25 is not a seal with a movable member, the sealing method has a degree of freedom. Therefore, it may be appropriately selected according to the assembly process, the shape of the developing device frame 17, and the like. Here, sealing can be performed by pouring an adhesive such as foam melt or hot melt. Alternatively, the gap 25 can be sealed by press-fitting the end seal support portion 22b and the developing device frame 17 by molding the support portion 22b with an elastic material such as an elastomer.

  The integration of the end seal will be described with reference to FIGS. FIG. 6 is an exploded sectional view for explaining the incorporation of the end seal, and FIG. 7 is an exploded perspective view for explaining the incorporation of the end seal.

  First, the end seal 22 is assembled toward the developing container 16 (arrow A direction). Similarly, the developing frame 17 is assembled (in the direction of arrow A), and then the end seal 22 is fixed. Similarly, the developing blade 19 and the developing roller 18 are assembled (in the direction of arrow A). As a result, the configuration shown in FIGS. 3 and 4 is obtained. As described above, the assembly of the end seal 22 can be completed only by assembling each member in one direction. As an assembly order, the end seal 22 is first assembled to the developing device frame 17 (in the direction of arrow B). Thereafter, the developing frame 17 may be assembled to the developing container 16. Here, as a method of coupling the developing frame 17 and the developing container 16, ultrasonic welding, thermal welding, forced vibration, adhesion, or the like can be used.

In the above-described embodiment, the developing device frame 17 and the developing container 16 are integrated as the cartridge frame. However, the present invention is not limited to this. For example, any cartridge frame that has a developing roller assembled thereto may be used.

  According to the above-described embodiment, the end seal 22 includes the supporting portion 22b having the arc-shaped portion 22d along a part of the peripheral surface of the developing roller 18 on the surface facing the developing roller 18, and the arc. The surface of the shape portion 22d has a seal portion 22a with flocking. Therefore, the pasting process for assembling the end seal, which was necessary in the conventional process, is eliminated. Therefore, the assemblability is improved. Also, skill in attaching the end seal is not required in manual assembly. In addition, the assembly apparatus is not complicated because the assembly process using a machine, a jig, or the like is a process of assembling a block instead of attaching a seal member. Also, there is no variation in pasting. Therefore, the sealing performance with the developing roller can be stabilized.

  Moreover, in the structure which concerns on a present Example, in order to plant each support part 22b, there is no cutting process. For this reason, fluff does not fall off in the subsequent process, and it does not cause image defects or require a cleaning process to avoid this.

In the above-described embodiment, the developing device frame 17 and the developing container 16 are integrated as the cartridge frame. However, the present invention is not limited to this. For example, any cartridge frame that has a developing roller assembled thereto may be used.

[Other embodiments]
In the above-described embodiment, the image forming apparatus C and the process cartridge 15 have been described using the configuration for forming a single color image as an example. However, the present invention is not limited to this, and can be suitably applied to an image forming apparatus in which a plurality of process cartridges are provided to form a multicolor image (for example, a two-color image, a three-color image, or a full-color image). Can do.

  The electrophotographic photosensitive member is not limited to the photosensitive drum, and may be a photosensitive belt.

  The process cartridge described above is, for example, an electrophotographic photosensitive member and at least a charging unit that is integrally provided. Therefore, the process cartridge according to the present invention means that at least the electrophotographic photosensitive member, the charging unit, and the developing unit having the features of the present invention are integrated into a cartridge, regardless of the presence or absence of other process units. This is within the scope of the present invention.

  The present invention can be used as an electrophotographic image forming apparatus employing an electrophotographic system.

It is a diagram illustrating a process cartridge having a developing device. 1 is a diagram illustrating a schematic configuration of an image forming apparatus. It is a figure explaining the structure of the edge part seal of the state which removed the developing roller. It is a partial cross section explanatory view of an end seal. It is a figure explaining the composition of an end seal. It is an exploded sectional view explaining integration of an end seal. It is a disassembled perspective view explaining incorporation of an end seal.

Explanation of symbols

C: Image forming apparatus main body D: Developing apparatus S: Sheet
11… Photoreceptor drum
12… Charging roller
13… Cleaning frame
14… Cleaning blade
15 Process cartridge
16 ... Developing container
17 ... Development frame
18… Developing roller
19 ... Developing blade
21… Developer supply opening
22… End seal
22a ... Seal part
22b ... support part
22d ... Arc shape part
22e ... Contact surface
23. Flexible sheet member
25… Gap
26… Surface
26a ... Surface of the arc-shaped part

Claims (5)

In a developing device for developing an electrostatic latent image formed on an electrophotographic photosensitive member,
A cartridge frame,
A developing roller for developing the electrostatic latent image;
A developer accommodating portion for accommodating a developer used for developing the electrostatic latent image by the developing roller, wherein a developer supply opening for supplying the developer in the developer accommodating portion to the developing roller is provided. A developer container having
An end seal that restricts leakage of the developer from a gap formed between the cartridge frame and the developing roller, disposed at one end and the other end in the longitudinal direction of the developing roller;
Have
The end seal is a support portion having an arc-shaped portion along a part of the peripheral surface of the developing roller on a surface facing the developing roller, and a seal portion having a flocked surface on the surface of the arc-shaped portion; A developing device comprising: The developing device according to claim 1, wherein the support portion has elasticity. The developing device according to claim 2, wherein a material of the support portion is an elastomer. In a process cartridge that can be attached to and detached from the electrophotographic image forming apparatus main body,
An electrophotographic photoreceptor;
A developing device according to any one of claims 1 to 3,
A process cartridge comprising: An electrophotographic image forming apparatus, wherein the process cartridge according to claim 4 is detachable.

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