Image forming apparatus using a photosensitive drum and having light quantity adjustment

摘要

An image forming apparatus for scanning a light beam modulated in accordance with image information using a rotational polygon mirror comprises a light beam generator for generating the light beam, an adjuster for adjusting the light quantity of the light beam generated by the light beam generator, a driver for driving the rotational polygon mirror in rotation, and a detector for detecting whether the rotational number of the rotational polygon mirror reaches a predetermined rotation number within a predetermined time. The light quantity adjuster starts the light quantity adjustment after the start of driving of the rotational polygon mirror with the driver, and before the rotation number of the rotational polygon mirror reaches the predetermined rotation number.