An image forming apparatus comprises a recording head for exposing a printing sheet by emitting lights under a condition that an exposure amount of the lights for each pixel is independently controlled and adjusted, an exposure amount determining section for determining whether the exposure amount is within a predetermined range, and a first exposure amount adjusting section for adjusting the exposure amount based on a light emitting time of the lights table including a relationship between a light emitting time and the density of an image, wherein the first exposure amount adjusting section resets the light emitting time table based on a determination of the exposure amount determining section.