| 摘要 |
PURPOSE:To increase the measurement range without increasing the mirror surface length of a traveling mirror in a range finder device. CONSTITUTION:A plurality of interference type range finder means 12, 13, and 14 opposing one traveling mirror 8 are aligned while they are separated by a short spacing L1 (=L2=L3=L4) for the length of a mirror surface in traveling direction and the interference type range finder means 12, 13, and 14 are switched according to the move of the traveling mirror 8, thus expanding the measurement range of distance to the mirror surface over a wire range for the mirror surface length of the traveling mirror 8. |
