| 摘要 |
PURPOSE:To measure the displacement of an object with high accuracy by juxtaposing another fiber for photodetection next to an optical fiber for light projection and photodetection, and determining a distance from the ratio between the quantities of the light which are made incident to the two fibers for photodetection and are reflected from the object. CONSTITUTION:The light of the quantity P1 of the light transmitted through an optical fiber 3 for light projection is radiated from an optical fiber 2 for light projection and detection toward an object 1. The quantity P2 of the light which is made incident through the fiber 2 to the 1st optical fiber 4 for photodetection and the quantity P3 of the light which is made incident to the 2nd optical fiber 6 for photodetection are detected. A distance (d) from the front end face of the fiber 2 to the object 1 is determined by the ratio between the quantities of said light and the displacement of the object 1 is measured. The relations between the quantities P1, P2, P3 of light and the distance (d) provide a curve 9. The distance (d) is determined with high accuracy over a wide range from the region I to the region II, whereby the displacement of the object 1 is measured accurately. |
