Distance measuring apparatus receiving echo light pulses

Claim 1

A distance measuring apparatus for measuring a distance to an object of concern, comprising: clock pulse generating means for generating a clock pulse signal at predetermined frequency; clock pulse delay means for delaying said clock pulse signal by an amount corresponding to an integral multiple of a time duration resulting from division of a period of said clock pulse signal by an integer (N) which is greater than 2 (two) to thereby generate a delayed clock pulse signal; light pulse generating means for generating a light pulse at a timing synchronous with a given one of the pulses of said delayed clock pulse signal; photo-detection means for receiving an echo light pulse resulting from reflection of said light pulse at said object and converting said echo light pulse into an electric signal; analogue-to-digital conversion means for converting the electric signal output from said photo-detection means to digital data at a timing synchronous with the individual clock pulses of said clock pulse signal; memory means for sequentially storing said digital data output from said analogue-to-digital conversion means; and processing means for imparting different delays to said clock pulse signal so that said delayed clock pulse signal is delayed by different amounts for N emissions to said light pulses, respectively, and synthesizing N sets of digital data stored in said memory means by rearranging on a time-serial basis said N sets of digital data to thereby arithmetically determine the distance to said object on the basis of a pulse waveform obtained by said synthesization.