| 摘要 |
PROBLEM TO BE SOLVED: To provide ideally overlapping laser beam spots on a photoreceptor surface by means of a simple arrangement and a simple optical system. SOLUTION: A plurality of upper waveguides 4 indicated by the full line and a plurality of lower waveguides 5 indicated by the broken line are formed in a total of two layers on a substrate 3 and the pitch Pb between the light exit end 4b of the upper waveguide 4 and the light exit end 5b of the lower waveguide 5 on the light exit side 3b of the substrate 3 is made smaller than the pitch Pa between the light incident end 4a of the upper waveguide 4 and the light incident end 5a of the lower waveguide 5 on the light incident side 3a of the substrate 3 to bring the waveguides into intimate contact with one another. At the light exit end 3b of the substrate 3, the light exit end 4b of the waveguide 4 indicated by the full line and the light exit end 5b of the waveguide 5 indicated by the broken line are arranged as core lines in a total of two layers for each one line and in a staggered fashion. |
