| 摘要 |
PROBLEM TO BE SOLVED: To control a deviation of an incidence position of laser light with respect to a light receiver as one aspect of the technology to be disclosed by the present application.SOLUTION: A band-pass filter 36 is configured to: allow reflection laser light L2 of a prescribed wavelength of the reflection laser light L2 to be incident upon a filter incidence surface 36A to be transmitted to a light receiver 40 side; allow an angle θof incidence of the reflection laser light L2 with respect to the filter incidence surface 36A to be changed accompanied by rotation of the band-pass filter, and change the prescribed wavelength allowing the reflection laser light to be transmitted to the light receiver 40 side; and allow an optical path of the reflection laser light L2 to be displaced. An optical path correction plate 38 is configured to: rotate in a direction opposite that of the band-pass filter 36 accompanied by the rotation of the band-pass filter 36; allow the angle of incidence θof the reflection laser light L2 with respect to a correction incidence surface 38A to be changed; and allow the optical path of the reflection laser light L2 to be displaced in a direction opposite a displacement direction of the optical path by the band-pass filter 36.SELECTED DRAWING: Figure 6 |
