JPS6356989B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fur brush type developing device used, for example, in electronic copying machines, electronic printing devices, and the like.

Recently, an economical fur brush type developing device that does not use a carrier (iron powder) has been proposed for electronic copying machines and the like. This type of developing device uses a fur brush developing roller with long bristles to stroke the surface of the photoconductor, and a fur brush with short bristles to soften the core and develop the surface of the photoconductor. There is a developing method using a fur brush developing roller that bends the part that comes into contact with the roller.

However, with the former fur brush developing roller with long bristles, the bristles become dull after long-term use, and the developing bias for preventing fogging is also ineffective, and to prevent this, it is necessary to add an anti-fogging roller. However, the disadvantage is that the structure is complicated.

On the other hand, the latter fur brush developing roller uses short bristles and has a soft core, and if the core and bristles (fur brush) are fixed with conductive adhesive, it is possible to apply a developing bias to prevent fogging. , the structure of the developing device is also simplified. However, with a structure in which the core and fur brush are directly bonded, when used for a long time, the conductivity tends to become uneven, and the core deteriorates over time. It becomes hard,
The effect was that the developing bias became ineffective due to partial defects.

The present invention has been made based on the above circumstances, and its purpose is to provide a fur brush developing roller with a soft core that has uniform conductivity even after long-term use, and to maintain good developing conditions over a long period of time. It is an object of the present invention to provide a fur brush type developing device that can obtain the following.

Hereinafter, one embodiment of the present invention will be described based on the drawings. Reference numeral 1 in FIG. 1 is a developing container communicating with a toner storage box (hopper), and a fur brush developing roller 4 whose part is in contact with the surface of the photoreceptor 3 is housed in the developing container 1. A preventive developing bias voltage is applied.

Further, a toner replenishment roller 6 is provided at the toner replenishment port of the toner storage box 2, and the toner 7 in the toner storage box 2 is supplied into the developer container 1 as the toner replenishment roller 6 rotates. It's getting old.

Further, the fur brush developing roller 4 has a structure as also shown in FIG. That is, a flexible cylindrical core body 9 made of latex or foamed polyurethane is formed on the outer peripheral surface of the rotating shaft 8 as a mandrel made of aluminum or stainless steel. Furthermore, a conductive rubber tube 10a is fitted onto the outer peripheral surface of the core body 9 to form a conductive rubber layer 10. Furthermore, a conductive adhesive 11 is applied to the outer peripheral surface of the conductive rubber tube 10a to make it wear-resistant and conductive.
Fur brush 1 made of fibers with higher specific resistance
2 is glued.

Furthermore, the rotating shaft 8 as a core metal and the conductive rubber tube 10a are connected via conductive adhesives 11, 11 applied to both end surfaces of the core body 9, and the conductive rubber tube 10a is attached to the back surface of the fur brush 12.
A uniform bias potential can be supplied from the rotating shaft 8 as a mandrel through a.

Thus, the toner 7 supplied into the developer container 1 by the toner replenishment roller 6 is transported between the fur brush 12 of the fur brush developer roller 6 and the bottom of the inner wall surface of the developer container 1, so that the amount of charge necessary for development is maintained. is maintained, and the uncharged toner is collected on the fur brush 12 side by the bias voltage applied from the back side of the fur brush 12, thereby reliably preventing fogging development due to the uncharged toner.

Further, since the conductive rubber layer 10 is interposed between the core body 9 of the fur brush developing roller 4 and the fur brush 12, unevenness in conductivity is unlikely to occur even after long-term use. There has never been a case where the core body 9 becomes hard over time or is partially damaged and the developing bias becomes ineffective.

In the above-described embodiment, the fibers forming the fur brush 12 are desirably configured in a seamless manner, but they are spirally formed in the conductive rubber layer 10.
It may be wrapped around the outer periphery of the fiber or may be electrostatically flocked with fibers. It goes without saying that the present invention can be implemented in various other ways without departing from the gist of the present invention.

As explained above, according to the present invention, it is possible to apply a uniform developing bias from the back surface of the fur brush without causing unevenness in conductivity even after long-term use, and without causing the core to become hard or partially damaged. Because it has a fur brush developing roller,
The effect is that good developing conditions can be obtained over a long period of time.

[Brief explanation of the drawing]

The drawing shows one embodiment of the developing device.
The figure is a schematic configuration diagram, and FIG. 2 is a partially cutaway sectional view showing the main part of the fur brush developing roller. 1...Developing container, 4...Fur brush developing roller,
9... Core body, 10... Conductive rubber layer, 12... Fur brush.

Claims (1)

[Claims] 1. In the fur brush developing roller, a conductive rubber layer is formed on the outer peripheral surface of a flexible core, and a conductive rubber layer is formed on the outer peripheral surface of the conductive rubber layer via a conductive adhesive. A developing device characterized by having a fur brush bonded to it.