| 摘要 |
PURPOSE:To reduce the material cost while minimizing the mounting density with a shorter length of a photo-receiver in an optical radar for measuring the distance to a target object by a method wherein a reflected ray from the object to be measured is focussed with a rotary paraboloid mirror and reflected back with a rotary hyperboloid mirror to converge on a photo receiving element. CONSTITUTION:A weak reflected ray Lr reflected from the object to be measured is introduced with a photo-receiver 22 from an opening 23a, focused with a rotary paraboloid mirror 24 and then, reflected back with a rotary hyperboloid mirror 25 to converge. The reflected ray Lr is once shaped to a parallel beams with a convex lens 27 in the photo receiving section 26 and passes through an interference filter 29 thereby increasing the sensitivity of the photo-receiver with a reduction in the transmission loss of the interference filter. The reflected ray Lr is converged again with a convex lens 25 to enter a photo receiving element 30, which outputs a received optical signal B. The signal B is amplified and shaped with a signal processing circuit 3 and fed to an arithmetic circuit 8 as a received optical pulse signal D to calculate the distance to the object to be measured from the delay time of the received optical pulse signal D with respect to a trigger signal C. |
