| 摘要 |
PURPOSE:To obtain a measuring optical system for a distance up to a target body and for its shape which forms an irradiation image of nearly constant size, by moving a light emitting lens system and a photodetecting lens system, having afocal lens groups, relatively to a light source and a detector on one stage at the same time. CONSTITUTION:In an afocal system, the focal point F1' of a lens group 7 which has focal points F1 and F1' and focal length f1, and the focal point F2 of a lens group 8 which has focal points F2 and F2' and focal length f2 are coincident with each other. When the lens groups 7 and 8 are both moved by (a) without moving an image point O', an object point O moves by {(f1/f2)<2>-1}. On this principle, a distance up to a target body and its shape are measured. In this case, light emitting lens groups made afocal are 2a and 2b, and photodetecting lens groups are 4a and 4b; and a light source 1, a detector 6, and a reflecting mirror 5 are moved in one body by said lens groups. |
