| 摘要 |
<p>PURPOSE:To mix and scan plural laser beams without any variation in the quantity of scanning light to each picture element by selecting oscillation wavelengths of two optical different semiconductor lasers in specific relation with a picture-element frequency and the light velocity. CONSTITUTION:Beams 41-44 from semiconductor lasers 11-14 arranged in parallel are reflected by mirrors 31-34 and made incident on a galvanometer mirror 5 to scan on a surface 7. The oscillation wavelengths lambdai and lambdaj of the mutually different lasers are selected so that ¦lambdai-lambdaj¦>=lambdailambdajM/c, where M is the picture-element frequency and (c) is the light velocity; and a beat frequency is set to >=5 times as high as the picture-element frequency. Consequently, varia tion in the quantity of scanning light to each picture element is prevented be cause of beats of the composite beam, and scan recording and scan reading is increased in precision sufficiently.</p> |
