Patent ID: 6647230
Filing Date: 2003-11-11
Classification: G03G

Abstract:
An image-forming apparatus comprising:an image-bearing member for holding thereon an electrostatic latent image; charging means for electrostatically charging a surface layer of said image-bearing member; an exposure unit for forming the electrostatic latent image on said image-bearing member by exposing said image-bearing member to light, said image bearing member having been charged by said charging means; and a developing unit, which includes a toner-carrying member for carrying and transporting a negatively-chargeable toner thereon, said toner-carrying member being brought into contact with said image-bearing member to form a developing zone where the toner is made to electrically adhere to the electrostatic latent image formed on said image-bearing member, to render the electrostatic latent image visible to form a toner image, wherein in a triboelectric series relationship formed between the toner and said surface layer of said image-bearing member, said surface layer of said image-bearing member has a charge polarity which is a different polarity with respect to a charge polarity of the toner in the developing unit, and wherein said image-bearing member having the electrostatic latent image has a surface potential, as a nonimage area potential (Vd) within a range of âˆ’500 to âˆ’800 V, and as an image area potential (Vl), at which the maximum toner image density is to be obtained, within a range of âˆ’50 to âˆ’200 V.