US Patent 7355618 Image exposure apparatus

An image exposure apparatus of a different angle incident type is provided having a single optical sensor unit for determining the timing for start point synchronization along the main scanning direction, an output level detecting device determining the output level of each beam of light which can be detected by the optical sensor unit, a first modulating device modulating the output level of each beam of light with a pixel data in the light path for exposure, and a second modulating device modulating the output level of each beam of light to a higher level outside of the light path for exposure than the level determined by said output level detecting device.