Patent ID: 7471377

Claim:
A laser distance measuring system adapted for measuring distance between said system and an object, said laser distance measuring system comprising: an object lens; a beam splitter disposed at one side of said object lens; a transmitter disposed at one side of said beam splitter opposite to said object lens, and operable to emit a laser beam that is split by said beam splitter into a measurement beam and a reference beam, the measurement beam passing through said object lens to reach the object and being reflected by the object to result in a reflected measurement beam that passes through said object lens; a receiver disposed at said one side of said object lens to receive the reflected measurement beam passing through said object lens and the reference beam from said beam splitter; and a shutter mechanism disposed adjacent to said receiver and including a beam masker that is operable to move between a first position, where said beam masker blocks path of the reflected measurement beam to said receiver and permits the reference beam to reach said receiver, and a second position, where said beam masker blocks path of the reference beam to said receiver and permits the reflected measurement beam to reach said receiver.