Patent ID: 7045771

Claim:
A light beam scanning apparatus comprising: light emitting means for emitting a light beam; scanning control means for controlling scanning of the light beam emitted by the light emitting means; light quantity detecting means for detecting the quantity of light in the light beam emitted by the light emitting means; light quantity control signal output means for outputting a light quantity control signal that performs control such that the quantity of light in the light beam emitted by the light emitting means is kept fixed on the basis of a result of detection of the quantity of light in the light beam executed by the light quantity detecting means; and light emission control means for controlling a light emission timing for the light beam from the light emitting means on the basis of image data and controlling the quantity of light in the light beam emitted by the light emitting means on the basis of the light quantity control signal while the light emission timing is being controlled, wherein the light emission control means controls the quantity of light in the light beam emitted from the light emitting means on the basis of the light quantity control signal in association with a light emission period which corresponds to the control of the light emission timing for the light beam based on the image data and which lasts a predetermined period or longer, the light emission control means starts light quantity control based on the light quantity control signal at an appropriate time to compensate for delay, on the basis of a delay in start of light quantity control determined from characteristics of the light quantity control signal, and the light emission control means ends light quantity control based on the light quantity control signal at an appropriate time to compensate for delay, on the basis of a delay in end of light quantity control determined from characteristics of the light quantity control signal.