Golf course range finder system

Claim 1

Apparatus for measuring the distance between a golfer and a pin located on a golf course, comprising: (a) an optical retroreflector mounted on said pin; (b) a transceiver adapted for operation by said golfer, the transceiver further comprising: (i) a hand holdable pistol shaped housing, the housing being formed so as to have a body portion, a handle portion and a barrel portion; (ii) optical transmitter means for generating optical pulses at a first repetition rate and for sending said optical pulses to said retroreflector, the optical transmitter further comprising an electronics module and an optical system, the electronics module residing in the body portion of the housing and the optical system residing in the barrel portion of the housing; (iii) optical receiver means for receiving and detecting optical pulses reflected from said retroreflector, and for generating a detected pulse signal indicative of said optical pulses, the optical receiver means residing with the optical transmitter means; and (iv) timing means for measuring the time difference between the leading edge of one said transmitted optical pulses and the corresponding leading edge of said corresponding detected pulse signal, the timing means further comprising: (A) a trigger, the trigger residing in the handle portion of the housing, operation of the trigger causing the optical transmitter means to generate and emit a pulsed wave train of coherent light, thereby creating a square waveform having a plurality of leading and trailing edges; and (B) a differentiator, the differentiator generating a plurality of control signals indicative of each edge position of the plurality of leading and trailing edges of the square waveform, the differentiator generating the control signals in response to the detected pulsed signal generated by the optical receiver means, thereby permitting the distance measurement to be accomplished by recording a time period between the leading edge of the emitted pulsed wave and the control signal generated in response to detection of the same leading edge of the reflected signal.