JPH07261550A - Developing device - Google Patents

Abstract

PURPOSE:To prevent a toner leak without using a filter liable to cause plugging by forming a recess facing an opening section on a cover member, and sticking a sheet material partitioning the opening section and recess to the cover member. CONSTITUTION:A rectangular elastic member 19 made of sponge is stuck to the periphery section of the inner bottom face of the box-shaped cover section 18 of a cover member 17 opened on the end face. An opening section 19a is formed at the center section of the elastic member 19. The elastic member 19 reaches a portion equal to or lower than the upper edge section 18a of the cover section 18. A sheet material 20 is airtightly stuck to the upper edge section 18a of the cover section 18, and it is preferably made of an expandable material. A through hole 18b for communicating the opening section 19a and the inner space of an image forming device is bored on the bottom section of the cover section 18. A better effect can be obtained against the internal pressure rise due to the elastic deformation of the elastic member 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device which is detachably attached to an electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art In recent years, image forming apparatuses such as electrophotographic copying machines and printers have become smaller and smaller, and the developing devices can be carried while being housed in the main body. In such a configuration, air may flow out from the developing device and toner may leak due to a shock of carrying. Therefore, in the conventional developing device, a filter is provided on the outer wall of the developing device to prevent the toner from leaking from the inside of the developing device and prevent the internal pressure from rising.

FIG. 8 is a perspective view of a conventional developing device taken out from the main body of the image forming apparatus. In FIG. 8, reference numeral 1 denotes a developing device main body, in which a developer, a developing roll and the like are stored. Reference numeral 2 is a toner cartridge that stores toner, and reference numeral 3 is a developing roll cover that protects the surface of the developing roll and prevents toner leakage. 4 is a filter, which is a toner cartridge 2
Is provided on the outer wall of the developing device main body 1 to prevent the toner from leaking due to the outflow of air due to the increase in the pressure inside the developing device body 1. The basis weight of the filter 4 is selected according to the particle size of the toner.

[0004]

However, in the above-described conventional configuration, when the amount of air outflow due to the increase in the pressure inside the developing device is large and the toner holding amount of the filter 4 exceeds a certain limit, the filter 4 is When clogging occurs, the flow of air between the developing device and the outside air is blocked, the internal pressure of the developing device rises, and the air flows out from the fine gaps other than the filter 4 in the developing device. Toner was leaking. Here, the developing device is mounted inside the image forming device, and the toner scattered inside the image forming device due to such toner leakage only adheres to the electric contact portion and causes functional failure such as contact failure. However, there was a problem of internal contamination due to toner stains.

Therefore, it is an object of the present invention to provide a developing device capable of preventing toner leakage without using a filter which easily causes clogging.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a developer accommodating portion for accommodating a developer, a developing roller for supplying the developer to an image carrier of an image forming apparatus through an opening, and an opening / closing opening. A cover member that covers as much as possible is provided, a recess facing the opening is formed in the cover member, and a sheet material that separates the opening and the recess is attached to the cover member.

[0007]

With the above structure, when the pressure inside the developing device increases or decreases, the sheet material expands or contracts to increase or decrease the substantial volume inside the developing device, so that the pressure inside the developing device can be adjusted appropriately. . As a result, the outflow of air from the inside of the developing device can be prevented, and the toner can be prevented from leaking as a result, and the toner can be prevented from interfering with the electrical contacts inside the image forming apparatus and from polluting the inside of the image forming apparatus. be able to.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an image forming apparatus equipped with a developing device according to the first embodiment of the present invention. 11
Is a developing device in which a toner cartridge 11a in which toner as a developer is stored, a stirring member 11b for stirring the toner in the toner cartridge 11a in the developing device, and a developing roll 11c are stored. 12 is an image carrier 12
The drum unit rotatably holds a. The developing device 11 and the drum unit 12 are detachably attachable to the image forming apparatus main body 13. In addition, 14 of the image forming apparatus main body 13 is an image carrier 12a.
A transfer unit that transfers the latent image formed on a print medium (not shown). A fixing unit 15 fixes the image transferred to the print medium. The fixed print medium is discharged to the outside of the image forming apparatus main body 13 by the conveying unit 16.

FIG. 2 is a perspective view of an unused developing device according to the first embodiment of the present invention. Reference numeral 17 denotes a cover member that covers an opening (not shown) corresponding to a connecting portion between the developing device 11 and the drum unit 12 when the developing device 11 is attached to the image forming apparatus main body 13, and 17a denotes a cover member 17
3B is a projection that is provided so as to project upward at the center of the upper edge and that is attached to a handle 11d provided outside the developing device 11 shown in FIG. 3B. When removing from 11, the user can easily remove it by putting his / her finger on the protrusion 17a.

The attachment of the developing device 11 to the image forming apparatus main body 13 will now be described with reference to FIG. Figure 3
(A)-(c) is installation explanatory drawing of the developing device in the 1st Example of this invention. FIG. 3A shows a packing state of the unused developing device 11, and from this state, the tape 1
1d is peeled off and the state shown in FIG. 2 is obtained. Next, the cover member 17 covering the opening is removed, and the developing device 1 is attached along the locking portion 13a of the image forming apparatus main body 13 as shown in FIG.
Insert 1. Next, as shown in FIG. 3C, the sheet 11e that separates the toner cartridge 11a from the developing unit containing the stirring member 11b can be pulled out to supply the toner in the toner cartridge 11a to the developing unit. To do. This completes the mounting of the developing device 11.

FIG. 4 is a detailed perspective view of the cover member covering the opening of the unused developing device in the first embodiment of the present invention. FIG. 5 is a sectional view of FIG. The cover member 17 comprises a box-shaped cover member 18 having an open end surface, and a square-shaped elastic member 19 made of sponge attached to the periphery of the inner bottom surface of the cover member 18. The elastic member 19 has an opening 19a formed in the center thereof. The elastic member 19 reaches the same or lower position as the upper edge portion 18a of the cover portion 18. Then, as shown in FIG. 5, the opening 19a of the elastic member 19 corresponds to a recess. A sheet material 20 is attached to the upper edge portion 18a of the cover portion 18 while keeping airtightness. The sheet material 20 is preferably a material that can expand and contract. The sheet material 20 may be attached not only to the upper edge portion 18a but also to the upper surface of the elastic member 19. In addition, a through hole 18b is formed in the bottom of the cover portion 18 to connect the opening 19a and the internal space of the image forming apparatus 13 to each other. By doing so, it is possible to obtain a better effect against the internal pressure rise due to the elastic deformation of the elastic member 19.

Next, the diaphragm structure of the cover member 17 having such a structure will be described. In FIG. 5, when the pressure in the developing device 11 rises due to a change in the environment or the action of an external force during transportation of the unused developing device 11, the internal air is pushed by the pressure and flows into the opening of the developing device 11. Therefore, pressure is applied to the cover member 17 attached to the opening. However, the cover member 17
A diaphragm is formed on the inner surface side by the elastic member 19 and the sheet material 20, and the opening 19a communicates with the outside of the developing device 11 through the through hole 18b.
Therefore, the internal pressure of the developing device 11 and the developing device 11
The sheet member 20 expands into the inside of the opening 19a so as to counteract the pressure outside, and expands the substantial volume inside the developing device 11 to mitigate the increase in pressure inside the developing device 11. . For this reason, air does not flow out from the inside of the developing device 11 and toner leakage is prevented.

FIG. 6 is a detailed perspective view of a cover member according to the second embodiment of the present invention, and FIG. 7 is a sectional view of FIG.
The present embodiment is different from the first embodiment in that the elastic member 19 is omitted and the concave portion corresponds to the internal space 18c of the cover portion 18, and the rest is the same, so the description is omitted.

[0014]

According to the present invention, a developer accommodating portion for accommodating a developer, a developing roller for supplying the developer to the image carrier of the image forming apparatus through the opening, and a cover for opening and closing the opening. Since a concave portion facing the opening is formed in the cover member and a sheet material for partitioning the opening and the concave portion is attached to the cover member, a change in the environment during transportation of an unused developing device or Even if the internal pressure rises due to the action of an external force, the expansion of the internal air is absorbed by the sheet material provided on the cover member, and the leakage of air to the outside is blocked, so that the toner leaks due to the air leakage. Therefore, the unused developing device and the image forming apparatus main body can be shipped together without any trouble.

[Brief description of drawings]

FIG. 1 is a sectional view of an image forming apparatus equipped with a developing device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of an unused developing device according to the first embodiment of the present invention.

FIG. 3A is an explanatory view of mounting the developing device according to the first embodiment of the present invention. FIG. 3B is an explanatory view of mounting the developing device according to the first embodiment of the present invention. Illustration of mounting the developing device in the example

FIG. 4 is a detailed perspective view of a cover member covering an opening of an unused developing device in the first embodiment of the invention.

5 is a sectional view of FIG.

FIG. 6 is a detailed perspective view of a cover member according to the second embodiment of the present invention.

7 is a sectional view of FIG.

FIG. 8 is a perspective view when the conventional developing device is taken out from the main body of the image forming apparatus.

[Explanation of symbols]

 11 developing device 13 image forming apparatus main body 17 cover member 18 cover portion 18b through hole 19 elastic member 20 sheet material

Claims (3)

[Claims] 1. A developing device mounted on the main body of an image forming apparatus, the developer containing portion containing a developer, and the developer being supplied to an image carrier of the image forming apparatus through an opening. A developing roller and a cover member that covers the opening so as to be openable and closable, a recess facing the opening is formed in the cover member, and a sheet material that separates the opening and the recess is attached to the cover member. A developing device characterized in that 2. The developing device according to claim 1, wherein the cover member has an elastic member that elastically holds the periphery of the sheet material. 3. The developing device according to claim 1, wherein the cover member has a through hole that communicates the recess with the outside.