| 摘要 |
PROBLEM TO BE SOLVED: To obtain an image with less density variation by a method wherein a temperature difference between light sources of LD array is lowered and the thermal crosstalk is reduced. SOLUTION: A video signal processing section 22 sequentially switches light sources for emitting lights in order to obtain a synchronous detecting signal (in order to allow a synchronous detecting sensor 11 to generate the synchronous detecting signal). That is, the channels are switched in the order of the channel 1, channel 2, channel 3, channel 4, channel 1, channel 2.... In order to execute emission of the light from the changed light source, a light emission signal for the channel is outputted to a corresponding PM section to allow the light source to output the light and the synchronous detecting sensor 11 to generate the synchronous detecting signal at each time of the switching. At that time, the emission power of the changed light source is varied corresponding to the arranged position of the light source. |
