Patent ID: 7528364
Filing Date: 2009-05-05
Classification: B23K,G01J,G02B,H04J

Abstract:
1. Apparatus comprising: a first steering reflector on which a beam of light is incident; a second steering reflector on which light reflected from the first steering reflector is incident; a first beam splitter on which light reflected from the second steering reflector is incident; a second beam splitter on which light reflected from the first beam splitter is incident; a first detector on which light reflected from the first beam splitter is incident; and a second detector on which light transmitted by the second beam splitter is incident; wherein a first value is obtained which is a function of an output signal of both detectors is indicative of a state of the first steering reflector and not of the second steering reflector, and a second value is obtained which is a function of an output signal of both detectors is indicative of a state of the second steering reflector and not of the first steering reflector.