| 摘要 |
<p>PURPOSE:To detect a preceding vehicle exactly even when exhaust gas, rain, fog etc. are in front of own vehicle by obtaining a correlative value between reflected signals binary coded reflected signals and phase shift signals phase shifted by a phase shifter by a comparator. CONSTITUTION:Laser light is transmitted from a transmitter 7 responding to random pulse signals generated by an (m) series generator 51 and reflected signals from a reflecting body are received by a receiver 9. A phase shifter 67 phase shifts random pulse signals successively, and a reference signal generating device 33 generates a reference signal of signal level corresponding to the amount of phase shifting of each phase shift signal phase shifted by the phase shifter 67. A comparator 61 compares the reference signal with reflected signals received by a receiver 9 and binary codes the reflected signals. A correlative value of the binary coded reflected signals and phase shift signals phase shifted by the phase shifter 67 is obtained by a correlating device 75 and the distance to the reflecting body is calculated by an arithmetic unit from the phase shift signal that gives maximum correlative value.</p> |
