Developing roller and developing method thereof

Abstract

Provided are a developing roller for non-magnetic single component development and a developing method employing the developing, by which toner can be stably conveyed in any external environment, and the stable toner conveyance and charging amount can also be acquired. Also disclosed is a developing roller possessing a spindle and provided around an outer circumference of the spindle, at least an elastic layer (innermost layer), a resistance adjusting layer (intermediate layer) formed on the elastic layer and a surface layer (outermost layer) formed on the resistance adjusting layer, wherein the intermediate layer possesses a layer containing carbon black in a resin, a content of a polycyclic aromatic hydrocarbon in the carbon black is at most 10 ppm, and a volume resistance (Rv) of all the layers provided around the outer circumference of the spindle is 1.0×107-1.0×1013 Ω·cm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements numbered alike in several figures, in which: FIG. 1 is a schematic cross-sectional view showing a roller structure of the present invention, FIG. 2 is a schematic cross-sectional view showing a developing device used for non-magnetic single component toner development, FIG. 3 is a schematic diagram showing an example of full color image forming apparatus, and FIG. 4 is a schematic diagram showing an apparatus to measure volume resistance.

Claims

1. A developing roller comprising a spindle and provided around an outer circumference of the spindle, at least an elastic layer (innermost layer), a resistance adjusting layer (intermediate layer) formed on the elastic layer and a surface layer (outermost layer) formed on the resistance adjusting layer, wherein the intermediate layer comprises a layer containing carbon black in a resin, a content of a polycyclic aromatic hydrocarbon in the carbon black is at most 10 ppm, and a volume resistance (Rv) of all the layers provided around the outer circumference of the spindle is 1.0×107-1.0×1013Ω·cm.

2. The developing roller of claim 1, wherein the surface layer further comprises a conductive agent.

3. The developing roller of claim 1, wherein the polycyclic aromatic hydrocarbon is formed from aromatic hydrocarbon compounds comprising naphthalene, fluorene, fluoranthene, chrysene, benzopyrene, anthracene, acenaphthylene and pyrene.

4. A developing process comprising the step of conducting non-magnetic single component development employing the developing roller of claim 1.

5. A developing process comprising the step of conducting non-magnetic single component development employing the developing roller of claim 2.

6. A developing process comprising the step of conducting non-magnetic single development employing the developing roller of claim 3.