Patent ID: 9599923
Date: 2017-03-21
CPC Classifications: G03G

Claim:
1. An image forming apparatus configured to form an image on a recording material, the image forming apparatus comprising: a photosensitive member; a charging device configured to charge the photosensitive member by a charging bias being applied to the charging device; an exposure device configured to expose the photosensitive member, which has been charged by the charging device, to light to form a latent image on the photosensitive member; a developer carrying member which carries a developer and which is configured to develop the latent image with the developer by a developing bias being applied to the developer carrying member; and a control portion configured to control the developing bias, wherein, when an image forming area is defined as an area on the photosensitive member on which an image to be transferred onto a recording material is formed, a printing portion is defined as an area in the image forming area to which the developer carrying member makes the developer adhere, a non-printing portion is defined as an area in the image forming area to which the developer carrying member does not make the developer adhere, and a non-image forming area is defined as an area on the photosensitive member disposed between two adjacent image forming areas in a moving direction of a surface of the photosensitive member, the exposure device exposes the printing portion in the image forming area at a first laser power, exposes the non-printing portion in the image forming area at a second laser power smaller than the first laser power, and exposes the non-image forming area at no laser power or a third laser power smaller than the second laser power, and wherein said control portion sets the developing bias to a first value when the developer carrying member is in a position which faces the image forming area, sets the developing bias to a second value when the developer carrying member is in a position which faces the non-image forming area, and sets the first value and the second value so that a difference between the second value and a value of the charging bias is smaller than a difference between the first value and the value of the charging bias.