| 摘要 |
PROBLEM TO BE SOLVED: To reduce the number of parts and assembly processes for easier assembly and disassembly, by forming a light-shielding palate for preventing stray light of transmission light and a reflection part which guides the light from a light emission part to a collimation optical system as one body. SOLUTION: The optical wave from a light emitting part 1 advances for a to-be-measured object through each upper-half part of a division prism 2, dichroic prism 3, objective lens 4. The reflection light reflected on the to-be- measured object is photo-detected at a photo-detecting part 5 through each lower-half part of the objective lens 4, dichroic prism 3, and division prism 2, and the distance from the to-be-measured object is obtained based on phase difference. A light-shielding plate 10a prevents the stray light of transmission light from photo-detected with the photo-detected part 5, while the light from a light emitting part 9 reflected on a reflection part 10a to illuminate a focal point plate 7 of collimation optical system. These light shielding plate 10 and reflection plate 10b are formed as one body, being an integrated part 10. Thus, the number of parts and assembly processes are reduced, to reduce cost. |
