| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical scanner in which the whole region of an effective scanning area on a face to be scanned is stably and accurately scanned with a light beam with a uniform spot diameter, and to provide an image forming apparatus using the optical scanner. Ž<P>SOLUTION: A mirror driving means adjusts a scanning time in which the effective scanning area PA is scanned with a light beam which varies by a resonant frequency-following control by adjusting the oscillation amplitude of a deflector 65 so that the scanning time falls within a predetermined error range of a preliminarily determined scanning time. Further, a light beam is focused on the whole effective scanning region PA with a substantially uniform spot diameter with a scanning lens 66 of which the F-value is kept constant over the whole region of the effective scanning region PA. Thus, the scanning time in which the effective scanning region PA is scanned with the light beam is kept substantially constant and the effective scanning region PA is scanned stably and accurately with the light beam which is focused with a substantially uniform spot diameter. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
