US Patent 7791635 Image forming apparatus and image forming method

In a disclosed image forming apparatus, a developing bias applied to a developer carrier or exposure energy with which an image carrier is exposed is adjusted such that an isolated one-dot image on the image carrier has a predetermined image density. When the image carrier is exposed to form dot images continuously arranged in a sub scanning direction, the exposure time period for each dot image is shorter than a time period for exposing the image carrier to form the isolated one-dot image.