Patent ID: 7599045
Filing Date: 2009-10-06
Classification: G01S,G02B

Abstract:
1. A method for eliminating internal reflection in a range finding system that transmits a first light beam along a first optic path to an object and receives a second light beam reflected by the object, internal reflection inducing by the first light beam in the range finding system being received by the range finding system as an internal reflection signal, the method comprising: (1) detecting an optical signal in the operation of the range finding system as a combination of the internal reflection signal and the second light beam; (2) converting the optical signal into an electrical current; (3) cropping the electrical current in a time interval for the electrical current to pass so as to generate a first electrical output corresponding to the internal reflection signal; and (4) subtracting the first electrical output from the electrical current to obtain a second electrical output representing the second light beam.