Patent ID: 6054717
Filing Date: 2000-04-25
Classification: B23Q,G01C,G02B

Abstract:
A target for locating the centerline of a reference beam, comprisinga target body having an input window and a viewing window spaced apart on said body,an axicon supported in said body adjacent said input window for intercepting a reference beam,said axicon having an optical axis and having at least one facet formed symmetrically about said optical axis,a viewing screen at said viewing window for receiving and displaying an image when the reference beam passes through said axicon,said axicon being adapted to form an image discernable at said screen, such image being symmetrical as to shape and intensity when such reference beam is coaxial with said optical axis of said axicon and being asymmetrical when such reference beam is not coaxial with said optical axis,whereby an observer can discern the image and determine when the image is symmetrical as the target is moved about the centerline of the reference beam.