Patent ID: 7510809

Claim:
An electrophotographic photoreceptor comprising a charge generating layer and a charge transfer layer on or over a support, the charge transfer layer including at least two layers of a support side layer and a surface side layer, wherein the support side layer contains A mol/cm 3 of a charge transfer material, and the surface side layer contains B mol/cm 3 of a charge transfer material having a dipolar moment of not more than 0.75, and inorganic particles having a number average primary particle diameter of 3-150 nm, wherein A and B satisfies relations of (1) and (2), 9.0Ã—10 âˆ’4 >A> 3.0Ã—10 âˆ’4 (1) 8.0Ã—10 âˆ’4 >B> 2.0Ã—10 âˆ’5 (2) wherein the support side layer comprises at least one of charge transfer materials having chemical structures (TL-1)-(TL-22) and wherein the surface side layer comprises at least one of charge transfer materials having chemical structures (TS-1)-(TS-11):