| 摘要 |
PURPOSE:To prevent error of distance measurement due to a reflective face by performing an operation with distance data based on a signal current, where the sum of currents of respective position detecting elements is smaller, by the first and the second position detecting means arranged on both sides of an optical axis. CONSTITUTION:Light receiving means 21 and 22 are provided a length l0 apart from an optical axis of a light projecting means 1 on both sides of the optical axis and are provided with optical systems 31 and 32 for light reception and one-dimensional position detecting elements 41 and 42 which operate data D0 of the distance to an object X to be detected on a basis of output currents I1A, I1B, I2A, and I2B. The signal current of the position detecting element, which does not receive regularly reflected components (omitted in the figure) of a reflected light R of the object X is discriminated in a control part 8 by smaller one of sums I1A+I1B and I2A+I2B of signal currents of elements 41 and 42 and is outputted as data D0. Thus, error of distance measurement due to regularly reflected components is prevented. |
