| 摘要 |
PURPOSE:To align the optical axis of a light transmission and photodetection optical system to the optical axis of a collimation optical system and to take an accurate measurement by reflecting external light transmitted through a translucent mirror by 90 deg. and then making it incident on a collimation telephoto optical system. CONSTITUTION:When distance is measured, transmitted light 9 passes through the hole of a rotary shutter plate 37 and when calibration is performed, the shutter plate 37 is rotated by a motor 38 to interpose a diamond prism 39 in the optical path of the transmitted light. Then, light from a light transmitting element 11 is incident on a prism 36 through a collimator lens 38 and reflected twice to form an optical path in parallel to the optical axis of the transmitted light. The projection light from the prism 36 is incident on an oblique surface 26 of the right-angled prism 24 of a collimation system, reflected there by 90 deg., and guided to a photodetecting element 3 through the center part of the optical axis of a photodetection lens 2. Consequently, a direct calibration optical path 40 extending from the element 11 to the element 3 is formed in the device to perform necessary calibration arithmetic. |
