Patent ID: 6227682
Filing Date: 2001-05-08
Classification: G02B,G03B

Abstract:
An image projection device comprisingan image source; andan optical device that illuminates said image source, said optical device comprisinga source of electromagnetic radiation,a target to be illuminated with at least a portion of the electromagnetic radiation emitted by said source,a first reflector comprising at least a portion of a paraboloid of revolution, said first reflector having an optical axis and a first focal point on said optical axis, said source being proximate to said first focal point such that some of the electromagnetic energy is organized into collimated rays parallel to said optical axis, anda second reflector comprising at least a portion of a paraboloid of revolution, said second reflector having an optical axis and a second focal point on said optical axis, said target being proximate to said second focal point, said second reflector being positioned and orientated with respect to said first reflector to receive a substantial portion of said collimated rays of electromagnetic energy so that said second reflector redirects said collimated rays toward said target,wherein said collimating reflector and said focussing reflector have substantially the same size and shape and are oriented substantially optically symmetrically with respect to each other so that substantially each ray of radiation reflected by a surface portion of said collimating reflector is reflected by a corresponding surface portion of said focussing reflector toward said target.