Patent ID: 6081333
Filing Date: 2000-06-27
Classification: G01J

Abstract:
A portable instrument for testing collimation of a beam, and measuring divergence and convergence of the beam from the instrument to a source of such beam, comprisinga housing having an input window for receiving the beam to be investigated and a viewing window at which adjacent images are displayed according to the collimation of the beam as it enters said input window,an optical element within said housing,said optical element including a matched pair of optical wedge plates having the same wedge angle and being supported side-by-side with their wedge directions opposite,said wedge plates extending at a predetermined angle to the axis of the input window,a viewing screen supported in said viewing window and providing a viewing screen for images,said wedge plate also extending at a second angle complementary to said to said viewing screen,whereby the adjacent fringe line images are back projected onto said viewing screen for viewing from the exterior of said viewing window; the improvement comprisinga telescope attached to said housing extending from said input window,said telescope comprising a pair of lenses supported for relative movement to each other,said lenses being adapted to receive a beam and to transmit such beam through said input window, andmeans for indicating the displacement of said lenses to display the distance from the source of the beam to the instrument when the fringe line images are visually equal.