Patent attributes
A beam detection sensor detects power of a laser beam from one of a plurality of light sources for each scanning of a scanning section to provide a light power signal. A laser control circuit compares a value of the light power signal with a predetermined value, adjusts a terminal voltage of a capacitor based on a result of the comparison, controls emission power of one of the light sources in accordance with the terminal voltage of the capacitor, and executes the control once for each light source during a plurality of scanning operations. An APC correction circuit corrects a reduction in the power of a laser beam in accordance with a reduction in electric charges applied to the capacitor caused by a leakage current during the plurality of scanning operations.
