| 摘要 |
PURPOSE:To measure a distance to an object with high accuracy by preparing a central optical system along a sensing axis and two crossed optical systems and by subtracting after amplifying outputs from light receiving means of the crossed optical systems. CONSTITUTION:A central optical system 10 along a sensing axis and two crossed optical systems 20, 30 are arranged. Each of the crossed optical systems 20, 30 has photoelectric conversion means 21, 31, whose outputs are inputted to be detected to detectors 91, 92 through AC amplifiers 61, 62 and filter circuits 81, 82. Outputs from the detectors 91, 92 are inputted to a subtraction means 40, from which the difference is outputted. Gain adjusting means 71, 72 are coupled to the amplifiers 61, 62, whose gains are adjusted automatically by the output from the detectors 91, 92. |
