JPH064352Y2 - Single component development unit holding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a device for holding a developing unit using a one-component developer in electrophotography, and can be used in the fields of copying machines, laser printers, facsimiles, and the like.

[Prior art]

In an electrophotographic copying apparatus, a constant pressing force is applied between a developing roller of a developing section using a one-component developer and a thin layer forming member for forming a thin layer of toner on the surface of the developing roller. , If the developing section is not used for a long period of time, the developing roller and the thin layer forming member are deformed by a constant pressing force, and as a result, the developing roller is deformed to cause horizontal stripes on the image. It was a drawback that adversely affected.

This development is a drawback found in a copying machine having a mono-color developing section which is not used for a long time and which is rarely used.

For this reason, when the developing unit is not used in the copying apparatus, providing an automatic release mechanism for releasing the pressing force between the developing roller and the thin layer forming member leads to an increase in cost, and if a manual release mechanism is provided, Due to the erroneous action, there is a drawback that the apparatus is operated with the pressing force being released, or the releasing operation of the pressing force is forgotten when not in use, and as a result, the image quality is adversely affected.

〔Purpose〕

The present invention is intended to eliminate the above-mentioned conventional drawbacks, and therefore, when the copying machine is not used, or when the developing machine is replaced with another developing section, the developing section is detached from the copying machine. By accommodating in the developing unit holding device, the thin layer forming member is released from pressure contact with the developing roller, deformation of the developing roller is prevented, and thus an image quality is not adversely affected.

〔Constitution〕

The one-component developing unit holding device according to the present invention includes a developing roller that develops by contacting a photoconductor, and a thin layer forming a thin toner layer on the surface of the developing roller that is placed under pressure against the developing roller. And a holding case capable of accommodating the one-component developing section, and a lid part of the holding case. Is provided with means for releasing the pressing force of the pressing member accompanying the closing operation of the lid.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an operating state of a one-component developing unit in a copying machine. Reference numeral 1 denotes a photosensitive drum, which has an electrostatic latent image and has a uniform thin toner layer on its surface. It is developed by the formed developing roller 2.

Regarding the supply of toner to the developing roller 2, the toner in the toner hopper 5 is agitated by the rotation of the agitator 4 to prevent blocking of the toner and send the toner in the toner hopper 5 to the toner supply roller 3 side. The toner supply roller 3 rotates counterclockwise in a state of being bitten by the developing roller 2, scrapes off the developed toner adhering to the developing roller 2 rotating counterclockwise, and sends it from the toner hopper 5. The toner is supplied to the developing roller 2. The toner supply roller 3 is made of an elastic material such as polyurethane foam.

On the developing roller 2, a thin layer forming blade 7 fixed to a blade holder 8 as a thin layer forming member with a double-sided tape or the like.
The toner is frictionally charged by the pressure contact between the thin layer forming blade 7 and the developing roller 2, and a uniform thin layer is formed on the surface of the developing roller 2. The blade holder 8 to which the thin layer forming blade 7 is fixed has one end 10a pushed up by a pressure spring 9 and is pressed by the other end 10c which is biased clockwise around the pivot portion 10b. The thin layer forming blade 7 is made of a rubber or resin-based elastic material, and the surface layer of the developing roller 2 is made of a rubber or resin-based elastic material, and a uniform toner thin film formed on the surface layer of the photosensitive drum 1 is formed. Development is performed by pressing the layers. 6
Is a toner cartridge.

As described above, when the developing unit is used in a copying machine, the thin layer forming blade 7 is pressed against the developing roller 2 to form a thin layer of charged toner on the surface of the developing roller 2. Although useful, when the copying machine is not used for a long period of time, the developing roller 2 is stopped.
The developing roller 2 and the thin layer forming blade 7 are deformed due to the pressure contact between the thin layer forming blade 7 and the thin layer forming blade 7, which causes a horizontal streak on the image.

In the present invention, the developing section which is not used is taken out of the copying machine and stored in the developing section holding case 11.

As shown in FIG. 2, the developing section holding case 11 serves as a developing roller 2, a toner supply roller 3, an agitator 4, a toner hopper 5, a toner cartridge 6, a thin layer forming blade 7, a blade holder 8 and a pressing means. The pressure spring 9 and the pressure lever 10 can be housed integrally, and the pressure spring 9 corresponds to the pressing position of the pressure lever 10 on the back surface of the lid 12 of the developing unit holding case 11. Then, the protrusion 13 is formed.

Therefore, by storing an unused developing portion in the developing portion holding case 11 and closing the case lid 12, the protrusion 13 formed on the case lid 12 is pressed against the pressure spring 9. The one end 10a of the lever 10 is pushed down, the pressure lever 10 rotates counterclockwise about the pivot portion 10b,
The contact between the pressure lever 10 and the blade holder 8 is cut off, the pressing of the blade holder 8 for fixing the thin layer forming blade 7 is released, and the pressure contact state between the thin layer forming blade 7 and the developing roller 2 is released. . The thin layer forming blade 7 is placed on the developing roller 2, and the own weight of the thin layer forming blade 7 and the blade holder 8 is about 20 to 30 g. Does not cause problems that affect the.

The developing portion housed in the developing portion holding case 11 when not in use is at least the developing roller 2, the thin layer forming blade 7, and a pressing member for pressing the thin layer forming blade 7 against the developing roller 2. Pressure spring 9, pressure lever 10
It does not mean that the provision of a developing unit other than that is not excluded.

Further, although the embodiment using the thin layer forming blade as the thin layer forming member has been described, a rotating roller is used to apply triboelectrification to the toner between the developing roller and the developing roller to form a uniform toner on the surface of the developing roller. A thin layer can be formed, and the pressing member for pressing the thin layer forming blade 7 against the developing roller 2 is not limited to the above embodiment, and a tension spring is used instead of the pressure spring. Various changes can be made.

When the copying machine is not used, the developing section is stored in a holding case, and in a copying machine for mono-color development, the developing section such as black, red, blue, green, and sepia can be used by the user as the developing section. When selecting and mounting and using it, it is possible to perform a suitable use such as storing an unused developing unit by replacing it with a holding case.

〔effect〕

With the configuration of the present invention, the developing unit that is not in use is housed in the holding case, and the thin layer forming member can be released from the pressure contact with the developing roller by opening and closing the case lid. In this case, there is an effect that a complicated means for releasing the pressure between the developing roller and the thin layer forming member is not required and the operation of the copying apparatus is not affected by an erroneous operation.

Further, although a developing unit having various colors is prepared for a copying apparatus capable of monocolor development, it is preferable to use it as a case for holding the developing unit when these developing units are not used.

Even in a copying machine, the developing unit can be made smaller than in the case where a complicated automatic release mechanism or a manual release mechanism for releasing the pressure contact of the thin layer forming member to the developing roller is provided, and the cost is reduced. Can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state where the developing unit is used in a copying machine, and FIG. 2 is a sectional view showing a state where the developing unit is housed in a holding case. 2 ... Developing roller, 7 ... Thin layer forming member, 9, 10 ... Pressing member, 11 ... Developing part holding case, 12 ... Case lid part, 1
3 ... Projection.

Claims (1)

[Scope of utility model registration request] 1. A developing roller that develops by contacting a photoconductor, a thin layer forming member that is arranged under pressure against the developing roller, and forms a thin layer of toner on the surface of the developing roller, and a thin layer forming member. A one-component developing section having a pressing member composed of a pressure lever operated by a spring for pressing the member against the developing roller, and a holding member which can be detached from the position where the one-component developing section is in contact with the photosensitive member and accommodated therein. A one-component developing unit holding device, characterized in that the lid of the holding case is provided with a protrusion for releasing the pressure of the spring of the pressing member when the lid is closed.