| 摘要 |
PURPOSE:To make it possible to accurately measure even an extremely short distance, by providing a first collimator for converging parallel light emitted from a range finding means and a second collimator optically connected to one terminal of an optical fiber. CONSTITUTION:Measuring light (parallel light) emitted from an optical range finder 1 is condensed by a first collimator 2 to be supplied to one terminal of an optical fiber 3 and the measuring light diffused from the other terminal of the optical fiber 3 is emitted as parallel light by a second collimator 4. The parallel light emitted from the second collimator 4 is reflected by a corner cube 5 and returned to the second collimator 4 through the same light path. In this case, an objective distance to be measured is the distance L between the second collimator 4 and the corner cube 5 placed to a predetermined place and the value, which is obtained by subtracting the length of the optical fiber 3 and the length between the first and second collimators 2, 4 from the measuring output of the optical range finder 1 by a subtractor 20, is measured as the aforementioned distance L. By this method, even an extremely short distance can be accurately measured. |
