| 摘要 |
PURPOSE:To provide an inexpensive range-finding device which can be adjusted easily for discriminating whether an object is located at a point which is closer or further from a set distance. CONSTITUTION:An oscillator 1 for generating pulses, a light emitting element 13 for emitting light for a specific time in synchronization with the output of the oscillator 1, a plurality of adjacent light reception elements 4 and 5 for receiving the reflecting light of the light emitting element 13, delay circuits 6 and 7 connected to each of the light reception elements, and a phase discrimination circuit 10 for comparing the output signal of each delay circuit with the phase of the output signal are provided. Also, a majority rule circuit is provided to count two different output levels of the phase discrimination circuit 10 for each specific time and to output a larger numeric value for extremely suppressing an erroneous judgment due to noise and the fluctuation in the judgment at the boundary of far and near points. |
