| 摘要 |
PURPOSE:To position a light-splitting prism easily and accurately by matching a mark on a photodetector substrate to that of the light-splitting prism. CONSTITUTION:On substrate 14 of a focusing detector provided with photodetectors 13a1... and 13b1 in lines 13a and 13b, a photomask punched in the mask pattern that corresponds to positioning marks 17a and 17b is matched to mask matching mark 16 and a photoresist film is exposed and developed, so that L-shaped marks 17a and 17b will be formed on the high-reflectance lead wire, etc., of substrate 14. On this substrate 14, optical-path splitting prism 12 is mounted and through a microscope, etc., the ridge line of prims 12 is matched to marks 17a and 17b, so that optical-path splitting prism 12 can be positioned accurately and easily. Instead of the ridge line, the side surface of prism 12, the half-mirror of prims 12 or marks formed on the totally reflective mirror surface parallel to it may be used. |
