Patent ID: 6829042
Filing Date: 2004-12-07
Classification: G01S

Abstract:
A distance measuring apparatus using a pulsed electromagnetic wave including:a single projector for projecting said electromagnetic wave to an object; branch means placed between said projector and said object to obtain a reference wave branched from said electromagnetic wave; a single receiver for receiving said reference wave and a reflection wave obtained when said electromagnetic wave is reflected off said object; delay means introduced into an optical path for said reference wave extending from said branch means to said receiver without interacting with said object to provide a delay time for delaying a reference-wave reception time, at which said reference wave is received by said receiver, such that a first time period between said reference-wave reception time and an electromagnetic-wave projection time, at which said electromagnetic wave is projected from said projector, is longer than a second time period between said projection time and a reflection-wave reception time, at which said reflection wave is received by said receiver; and a processor for calculating a time difference between said reference-wave reception time and said reflection-wave reception time from outputs of said receiver, and determining a distance between the distance measuring apparatus and said object according to said time difference and said delay time.