JPH10149018A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device which can prevent deterioration such as melting or deformation of toner seal members caused by permeation of toner and also toner leak from the developing device and poor image formation performance resulting from deterioration of the toner seal members. SOLUTION: A developing device 1 is equipped with a toner holder 10 in the form of approx. circular column borne in a housing 6, toner seal members 2 installed slidably on the side faces of the toner holder ends, and toner accommodated in the housing 6. Each toner seal member 2 is equipped with a resilient foaming body 2a and a skin layer 2b which is formed on the foaming body 2a slide contact surface with the toner holder 10 and does not admit permeation of the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device provided in an image forming apparatus such as a copying machine or a printer.

[0002]

2. Description of the Related Art In recent years, in image forming apparatuses such as copiers and printers, there has been an increasing demand for improvement in image quality and speeding up of image formation. Hereinafter, a conventional image forming apparatus will be described with reference to the drawings.

FIG. 3 is a sectional view of a main part of a conventional image forming apparatus. 3, 5 is a developing device, 6 is a developing device housing, 7 is a toner stirring member, 8 is toner, 9 is a toner supply roller, 10 is a toner holding member, 11 is a toner thinning blade, and 12 is a toner holding member. Power supply, 13 is a photoconductor,
14 is a charger, 15 is a paper cassette, 16 is paper, 17
Is a feed roller, 18a and 18b are transport rollers, 19 is a registration roller, 20 is a driven roller, 21 is a transfer roller,
22 is a fixing device, 22a is a heat roller, 22b is a pressure roller, 23 is a static eliminator, 24 is a cleaning blade, 2
Reference numeral 5 denotes a toner seal member.

Referring to FIG. 3, the configuration of a conventional image forming apparatus and the image forming operation will be described. When the image forming operation of the image forming apparatus is started, in the developing device 5, the toner 8 housed in the developing device housing 6 is transferred to the toner stirring member 7.
To the toner supply roller 9 side. Accordingly, the toner supply roller 9 and the toner holder 10 rotate, and the toner 8 attached to the surface of the toner supply roller 9 is supplied to the surface of the toner holder 10. Toner holder 10
Is triboelectrically charged by the toner thinning blade 11 and is thinned on the surface. At this time, the photosensitive member 13 disposed adjacent to the toner holding member 10
Rotates in a direction opposite to that of the toner holding member 10, and the surface of the photoconductor 13 is charged by the corona discharge of the charger 14. The photoreceptor 13 is composed of a cylindrical metal rotating body and a photosensitive receiving layer made of selenium or an organic photoconductor formed in a thin film on the surface thereof. (Not shown), an exposure light beam corresponding to the content of the image to be formed is irradiated, and an electrostatic latent image is formed. Thereafter, in a state where a predetermined bias voltage is applied from the toner holder power supply 12 to the toner holder 10, the toner holder 1
0 and the photoconductor 13 contact while rotating.
The upper electrostatic latent image is developed by the toner 8 supplied from the toner holding member 10, and a toner image is formed on the photosensitive member 13.

On the other hand, the paper 16 held in the paper supply cassette 15 is carried out by the paper supply roller 17 and is sequentially delivered in the direction of arrow A by the conveyance rollers 18a and 18b. Between the photoconductor 13 and the transport rollers 18a and 18b, there are provided a registration roller 19 and a driven roller 20 for waiting the paper 16 so that the toner image on the photoconductor 13 is transferred to a predetermined position of the paper 16. It is arranged.

When the sheet 16 is conveyed to the position of the photoconductor 13, the transfer roller 2 to which a bias voltage having a polarity opposite to the bias voltage applied to the photoconductor 13 is applied.
When the sheet 16 is brought into contact with the photoconductor 13 by 1, the toner image on the photoconductor 13 is transferred to the sheet 16. The transferred toner image is fixed on the paper 16 when the heat roller 22a and the pressure roller 22b provided in the fixing device 22 rotate and the paper 16 is conveyed while being nipped between them. Is done. After the toner image is transferred to the paper 16, the toner 8 remaining on the photoconductor 13 is removed by the cleaning blade 24, and the remaining charge is removed by the charge remover 23.

Next, the configuration of the developing device will be described in more detail. FIG. 4 is a cutaway perspective view of a main part of a developing device of a conventional image forming apparatus. As shown in FIG. 4, a substantially cylindrical toner supply roller 9 having a surface formed of an elastic material such as urethane or silicon and a toner holding member 10 are adjacently supported on the developing device housing 6. . During the image forming operation as described above, the toner holding member 10 has a peripheral speed of 336 mm.
/ Sec, the toner supply roller 9 also rotates in the same direction as the toner holder 10 at a peripheral speed of about 168 mm / sec, and the toner supply roller 9 is brought into contact with the toner holder 10 and the toner supply roller 9. From 9, toner is supplied onto the toner holding member 10. Since the toner on the toner holder 10 is thinned to a predetermined thickness by the toner thinning blade, excess toner is pushed to both ends of the toner holder 10. A substantially U-shaped toner seal member 25 made of an elastic foam such as urethane or silicone is slidably provided on both side surfaces of the toner holding member 10 so that toner leaks to both ends of the toner holding member 10. Has been prevented.

[0008]

However, in the above-mentioned conventional developing device, an elastic foam having good slidability with respect to the toner holder is used as the toner seal member. The toner penetrates into the elastic foam over time from the sliding contact surface with the foam, and the elasticity of the toner seal member is lost, and frictional heat is generated between the toner holder and the toner seal member rotating at high speed. In addition, there has been a problem that the toner seal member is melted or deformed, thereby causing toner leakage from the developing device and image defects.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and prevents the toner sealing member from dissolving or deforming due to permeation of toner and preventing toner leakage from a developing device and image defects due to deterioration of the toner sealing member. It is an object of the present invention to provide a developing device capable of performing the above.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a substantially cylindrical toner holder pivotally supported in a housing of a developing device, and slides on both side surfaces of both ends of the toner holder. A developing device comprising a toner seal member and a toner housed in a developing device housing, wherein the toner seal member is formed on a sliding contact surface between a foam layer and a toner holder of the foam layer. And a skin layer that does not allow the applied toner to penetrate.

With this configuration, it is possible to prevent the toner from penetrating into the foam layer from the sliding contact surface of the toner seal member with the toner holding member by the skin layer, and the elasticity of the toner seal member due to the intrusion of the toner can be prevented. Is lost,
It is possible to prevent the toner seal member from being melted or deformed by friction generated between the toner seal member and the toner holding member.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, there is provided a substantially cylindrical toner holder rotatably supported in a developing device housing, and a toner slidably provided on both side surfaces of both ends of the toner holder. A developing device comprising: a seal member; and a toner housed in a developing device housing, wherein the toner seal member is formed on a sliding contact surface between the foam layer and the toner holder of the foam layer. And a skin layer that does not allow the toner to penetrate, and the skin layer prevents the toner from penetrating into the foam layer from the sliding surface of the toner seal member with the toner holding member. Becomes possible,
The toner seal member loses elasticity due to the intrusion of the toner, and has an effect of preventing the toner seal member from being dissolved or deformed by friction generated between the toner seal member and the toner holding member.

Here, the foam layer has elasticity,
Either a closed cell or an open cell may be used, and a urethane resin or a silicone resin is used as a material, and a urethane resin is particularly preferable.

As a method of integrally forming the foam layer and the skin layer, for example, a portion of the foam layer such as urethane resin or silicone resin which is to be in contact with the toner holding member is heated in advance. Alternatively, there is a method in which the surface is immersed in a solvent such as toluene, or the solvent is applied and sprayed. Thereby, the surface of the foam layer is melted or dissolved at a predetermined thickness,
By curing, a dense thin layer that does not allow toner to penetrate into the surface of the foam layer can be formed.

According to a second aspect of the present invention, there is provided the sealing tape according to the first aspect of the present invention, wherein the sealing layer is affixed to the surface of the foam layer which is in sliding contact with the toner holding member instead of the skin layer. This prevents the toner from penetrating into the foam layer in the same manner as the skin layer, and loses the elasticity of the toner seal member due to the intrusion of the toner. The resulting friction dissolves the toner seal member,
Alternatively, it has the effect of preventing deformation. In addition, when the seal tape is worn out, it can be replaced and the maintenance is facilitated.

Here, as the seal tape, a material made of a dense material which does not cause a chemical change or the like by the toner and does not penetrate the toner is used, and a material made of Teflon or Capcom is particularly preferable. .

According to a third aspect of the present invention, in the second aspect, both ends of the seal tape are fixed to the housing of the developing device. Since the toner holding member is fixed to the developing device housing, the slidability and stability of the seal tape when the toner holding member rotates at a high speed can be improved.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the thickness of the skin layer or the seal tape is 10 μm to 40 μm. In addition, it has the effect of exhibiting excellent durability against friction caused by high-speed rotation of the toner holding member and having excellent adhesion to the foam layer.

A specific example of the embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a cutaway perspective view of a main part of a developing device according to an embodiment of the present invention. In FIG. 1, 1 is a developing device, 2 is a toner seal member, 2a is an elastic foam,
Reference numeral 2b denotes a skin layer, and the developing device housing 6, the toner supply roller 9, the toner holding member 10, and the toner thinning blade 11 are the same as those in the conventional example.

The developing device 1 according to the present embodiment is different from the conventional example in that a toner seal member 2 slidably provided on both side surfaces of a toner holding member 10 includes an elastic foam 2a and a toner of the elastic foam 2a. And a skin layer 2b formed integrally on the sliding contact surface with the holding member 10 so as not to penetrate the toner.

Since the toner seal member 2 has the skin layer 2b on the sliding surface with the toner holding member 10, the toner penetrates into the elastic foam 2a of the toner seal member 2 from the sliding surface. Can be prevented. Therefore, if the elasticity of the foam layer is lost due to the intrusion of the conventional toner, frictional heat is generated between the toner carrier and the foam layer which rotate at a high speed, and the toner seal member is dissolved or deformed, and toner leakage is prevented. Although this was a cause, according to the present embodiment, such a problem can be solved.

(Embodiment 2) FIG. 2 is a cutaway perspective view of a main part of a developing device according to an embodiment of the present invention. In FIG. 2, 3 is a developing device, 4 is a toner seal member, 4a is an elastic foam, 4b is a seal tape, and a developing device housing 6, a toner supply roller 9, a toner holding member 10, and a toner thinning blade 11 are conventional. Since it is the same as the example, the same reference numerals are given and the description is omitted.

The developing device 3 of this embodiment is different from that of the first embodiment in that a toner seal member 4 slidably provided on both side surfaces of a toner holding member 10 has an elastic foam 4a.
And a sealing tape 4b, which is adhered to a surface of the elastic foam 4a that is in sliding contact with the toner holding member 10 and does not allow toner to penetrate,
It is to have.

According to this configuration, the sealing tape 4b prevents the toner from entering the elastic foam 4a, and
As in the first embodiment, the elastic foam 4a can be prevented from melting or deforming due to frictional heat to prevent toner leakage, and can be worn away by using the seal tape 4b instead of the skin layer. In this case as well, only the seal tape 4b can be replaced, and maintenance can be facilitated.

Further, as shown in FIG.
Since the seal tape 4b is independently fixed to the developing device housing by fixing both end portions of the sealing tape 4b to the developing device housing 6, the slidability and stability of the seal tape 4b when the toner holder 10 rotates at high speed. Can be improved.

[0026]

As described above, according to the developing device of the present invention, the penetration of the toner into the inside of the toner sealing member is prevented by the skin layer or the sealing tape through which the toner cannot penetrate, and the friction generated between the toner holding member and the toner holding member. Can prevent the toner seal member from being dissolved or deformed, so that it is possible to prevent toner leakage between the toner container and the toner holder, image defects due to the toner leakage, and contamination in the image forming apparatus. Excellent effects can be obtained. Further, by preventing toner leakage, an excellent effect that the toner can be used without waste can be obtained.
Further, since contamination in the image forming apparatus due to toner leakage can be prevented, an excellent effect that maintenance and management of the image forming apparatus becomes easy can be obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part of a developing device according to an embodiment of the present invention.

FIG. 2 is a cutaway perspective view of a main part of the developing device according to the embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a conventional image forming apparatus.

FIG. 4 is a cutaway perspective view of a main part of a developing device of a conventional image forming apparatus.

[Explanation of symbols]

 1, 3, 5 Developing device 2, 4 Toner seal member 2a, 4a Elastic foam 2b Skin layer 4b Seal tape 6 Developing device housing 7 Toner stirring member 8 Toner 9 Toner supply roller 10 Toner holder 11 Toner thinning blade 12 Power supply for toner holder 13 Photoreceptor 14 Charger 15 Paper feed cassette 16 Paper 17 Paper feed roller 18a, 18b Transport roller 19 Registration roller 20 Follower roller 21 Transfer roller 22 Fixing device 22a Heat roller 22b Pressure roller 23 Static eliminator 24 Cleaning Blade 25 Toner seal member

Continued on the front page (72) Inventor Tetsuhiro Tsuru 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] A substantially cylindrical toner holder rotatably supported in a housing of the developing device; a toner seal member slidably provided on both side surfaces of the toner holding member; and a toner storage member housed in the housing of the developing device. A toner layer, wherein the toner seal member has a foam layer, and a skin layer formed on a sliding contact surface of the foam layer with the toner holding member and not penetrating the toner. And a developing device. 2. The developing device according to claim 1, further comprising a seal tape attached to a surface of said foam layer which is in sliding contact with said toner holding member, instead of said skin layer. apparatus. 3. The developing device housing according to claim 2, wherein both ends of said sealing tape are fixed to said developing device housing.
3. The developing device according to claim 1. 4. The developing device according to claim 1, wherein said skin layer or said seal tape has a thickness of 10 μm to 40 μm.