Patent ID: 6102554
Filing Date: 2000-08-15
Classification: F21S,F21V,F21W,G02B,G03B

Abstract:
Apparatus for modifying a beam of light, comprising at least one set of blades moveable across the beam, wherein said at least one set of blades is arranged into a first subset of co-planar blades and a second subset of co-planar blades, wherein the respective subsets of blades are axially spaced from and parallel to each other and wherein the blades are moveable between an open position in which they are retracted out of the light beam and a closed position in which a part but not all of the light beam is intercepted by blades in the first subset and a part but not all of the light beam is intercepted by blades in the second subset and in which the light beam is substantially totally intercepted by said blades.