| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect inclination by providing a reflection part for reflecting light with only a specific wavelength band at a flat part where normal and optical-axis directions coincide each other. SOLUTION: The emission light of a light source 11 becomes parallel luminous flux by a collimate lens 13 via a pin hole 12a of a pin hole plate 12, is reflected by a beam splitter 14 and enters lens 17, is partially reflected by a lens functional part 17a, and is transmitted through the large part. On the other hand, the large part is reflected by a reflection part 18 of the lens functional part 17a. Then, the reflection light reaches a photodetector 16 via the beam splitter 14 and a collimate lens 15. At this time, the reflection light of a flat part 17b forms a condensation spot at one point on the photodetector 16, while the reflection light of the lens functional part 17a forms a spot being spread to the surrounding of the condensation spot. By detecting a condensation spot position on the photodetector 16 of the flat part 17b, the inclination of the lens 17 can be detected. |
