Optical rangefinder

摘要

A range finder is proposed which has an optical transmitter and an optical receiver and in which the measurement path is included in the formation of a frequency of a naturally oscillating circuit. In this case, the propogation time of the light determined the oscillator frequency, the oscillator frequency being low at a large range and the oscillator frequency being high at a short range. An up/down counter is triggered by repeated measurement and normalisation to a specific count, which counter counts upwards when measuring the measurement path and counts backwards when measuring a reference path. The difference between the values is a measure of the measurement path, which can be indicated appropriately. <IMAGE>