Patent ID: 8086148

Claim:
An electrophotographic image forming apparatus, comprising: a photoconductor body which moves at a predetermined process speed, the photoconductor body to have an electrostatic latent image on a surface thereof; a donor roller which moves based on movement of the photoconductor body in a direction equal to or opposite to a moving direction of the photoconductor body and develops the electrostatic latent image on the surface of the photoconductor body by using charged toner electrostatically carried on a surface of the donor roller; a development nip section formed between the photoconductor body and the donor roller by having a predetermined gap between the photoconductor body and the donor roller; and a developing traveling-wave electrode for generating a traveling-wave electric field disposed at a position facing the surface of the donor roller at an upstream side of the moving direction of the photoconductor body relative to the development nip section separated from the donor roller, a traveling direction of the traveling-wave electric field from the developing traveling-wave electrode is toward a side of the development nip section, wherein: a distance between the donor roller and the developing traveling-wave electrode is greater at a downstream side than at an upstream side of the traveling direction of the traveling-wave electric field, and the toner is released from the side of the developing traveling-wave electrode to the side of the development nip section.