Laser-based coordinate measuring device and laser-based method for measuring coordinates

Abstract

A laser based coordinate measuring device measures a position of a remote target. The laser based coordinate measuring device includes a stationary portion, a rotatable portion, and at least a first optical fiber. The stationary portion has at least a first laser radiation source and at least a first optical detector, and the rotatable portion is rotatable with respect to the stationary portion. The first optical fiber system, which optically interconnects the first laser radiation source and the first optical detector with an emission end of the first optical fiber system, has the emission end disposed on the rotatable portion. The emission end emits laser radiation to the remote target and receives laser radiation reflected from the remote target with the emission direction of the laser radiation being controlled according to the rotation of the rotatable portion.

What is claimed is: 
     
         1 . A distance measuring apparatus for measuring a distance from the apparatus to an object, comprising:
 a first lens system including at least one lens;   a first source of light and a second source of light, a first light from the first source and a second light from the second source transmitted toward the object, the first light having a first wavelength and the second light having a second wavelength different from the first wavelength, a first portion of the first light reflected by the object and a second portion of the second light reflected by the object, the first portion and the second portion passing through at least a portion of the first lens system;   a first optical detector that detects the first portion and a second optical detector that detects the second portion; and   a first dichroic beam splitter and a second dichroic beam splitter, each dichroic beam splitter adapted to reflect at least one of the first light and the second light toward the first optical detector and the second optical detector, respectively.   
     
     
         2 . The distance measuring apparatus according to  claim 1  wherein the first dichroic beam splitter and the second dichroic beam splitter are plates. 
     
     
         3 . The distance measuring apparatus according to  claim 1  wherein a first mirror redirects at least one of the first portion and the second portion toward one of the detectors. 
     
     
         4 . The distance measuring apparatus according to  claim 1  further comprising:
 a structure rotatable about a first axis and a second axis, the structure including the first lens system and at least a portion of a distance meter, wherein the distance meter includes the first light source, a first beam of first light launched through a portion of the first optical system to the object, the distance meter configured to measure a first distance from the apparatus to the target based at least in part on the speed of light; 
 a first encoder that measures a first angle of rotation about the first axis; and 
 a second encoder that measures a second angle of rotation about the second axis. 
 
     
     
         5 . The distance measuring apparatus according to  claim 4 , wherein the object is a retroreflector target. 
     
     
         6 . The distance measuring apparatus according to  claim 5 , further comprising:
 a position detector that collects from a portion of the first optical system a portion of the beam reflected by the target; and   a first electronics system that causes the beam to track the target based at least in part on a signal from the position detector, wherein the tracking is obtained by rotating the structure about the first axis and the second axis.