| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical scanner capable of maximizing an angle range enabling writing by a rotary polygon mirror, suppressing increase in an optical path length when a rotary polygon mirror is down-sized, and reducing deterioration of optical characteristics. <P>SOLUTION: A first light beam Ba and a second light beam Bb are deflected on different surfaces of a rotary polygon mirror 6 and reach to first and second surfaces to be scanned through first and second scanning optical systems 7a and 7b. The first and second scanning optical systems 7a and 7b have first and second synchronization detection optical systems for entering the first and second light beams into a single synchronization detection element 12. A relationship between a period of time Td1 after a light beam reflected by the rotary polygon mirror passes through the first synchronization detection optical system and is detected by the synchronization detection element until writing is started on the first surface to be scanned, and a period of time Td2 after a light beam reflected by the rotary polygon mirror passes through the second synchronization detection optical system and is detected by the synchronization detection element until writing is started on the second surface to be scanned, is Td1<Td2. <P>COPYRIGHT: (C)2013,JPO&INPIT |
