| 摘要 |
PURPOSE:To facilitate position aligning of a substrate and a lens means, by integrally forming of 2 lens means and the substrate. CONSTITUTION:A lens substrate 3 is installed between a substrate 1 and a movable mirror 4 and 2 lenses 3A, 3B are formed on this substrate 3. Fresnel lenses 3A, 3B can be manufactured by etching, for example, on a surface of soda glass substrate 3. Construction is so set that focal planes of these lenses 3A, 3B flush with the rear surface of the substrate 3, that is to say, focal distances of these lenses 3A, 3B are equalized with the thickness of the substrate 3. Center distance at the output ends of the wave-guiding paths 14, 24 and center distance of the lenses 3A, 3B are set with the same distance apart. And, the lens substrate 3 contacts its rear surface with the end surface of the substrate 1 in such a way that the centers of the lenses 3A, 3B are set in perfect alignment with the center of the output ends of the light-guiding paths 14, 24. |
