| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical scanner that can suppress a variation in outputs of synchronization signal detection means between different optical scanners, while suppressing a reduction in output of the synchronization signal detection means.SOLUTION: An optical scanner includes: an aperture element 7 that is arranged between a light source (semiconductor laser 1) and a light deflector (polygon mirror 3) to regulate the width of light beams emitted from the light source; and light beam restriction means (synchronization slit 12) that is arranged in a light path between the light deflector and synchronization signal detection means and blocks at least a part in the main scanning direction of the light beams from any light-emitting part of the light source deflected by the light deflector. The light beam restriction means is arranged off-center such that the light intensity distribution in the main scanning direction of the light beams that have passed through the light beam restriction means becomes asymmetric with respect to the principal ray C of the light beams that have passed through the aperture element. |
