| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent deterioration of an image by suppressing fluctuation in a light quantity of an optical beam due to a temperature rise of a light-emitting point and ambient temperature fluctuation, in a scanning optical device that is required to be set long in a period of an APC control of each light-emitting point. <P>SOLUTION: This scanning optical device comprises: a photodiode PD1 for detecting the light quantity output by a semiconductor laser diode LD100; a constant current source Q111 supplying an output according to the light quantity detected by the photodiode PD1; a capacitor C111 retaining a voltage applied to the semiconductor laser diode LD100; and a constant voltage source Q113 supplying an output according to the voltage retained by the capacitor C111. In an APC mode, the output of the constant current source Q111 is supplied to the semiconductor laser diode LD100 and, in a printing mode, the output of the constant voltage source q113 according to the voltage retained by the capacitor in the APC mode is supplied to the semiconductor laser diode LD100. <P>COPYRIGHT: (C)2012,JPO&INPIT |
