| 摘要 |
PURPOSE:To provide a developing roller for electrophotography where developer carrying capacity is high and an abnormal image such as void, longitudinal line thinning, and also the gradation unevenness of stripe pattern or the like is hardly caused. CONSTITUTION:A dielectric part 10 has a projection line 11 whose cross section is trapezoidal, where regular surface ruggedness of a specified pitch in a roller shaft direction is formed, and which is extended in a nearly peripheral direction, and the pitch of ruggedness of the projection line 11 is set to be >=0.3mum to <=500mum. When it is assumed that the pitch of ruggedness of the projection line 11 is deltaf and the main scanning direction pitch of light irradiating a latent image carrier from the optical writing system of an electrophotographic device corresponding to the light emitting cycle of a light source is deltaL, the pitch deltaf of ruggedness of the projection line 11 is more preferably set out of the range of + or -15% of the pitch deltaL taking the main scanning direction pitch deltaL of the light as a reference. |
