COMPACT OPTICAL SYSTEM AND LENSES FOR PRODCUING UNIFORM COLLIMATED LIGHT

摘要

An optical system includes a cylindrical side emitter lens, a reflector and a cylindrical Fresnel lens to produce a substantially uniformly illuminated exit plane with well collimated light in the forward direction. The cylindrical side emitter lens redirects light from a light source, such as a number of light emitting diodes placed in a straight line, into side emitted light along an optical axis that is parallel with the exit plane. The reflector may be a stepped multi-focal length reflector that includes multiple reflector surfaces with different focal lengths based on the surfaces distance to the light source and height to redirect light from the cylindrical side emitter lens to illuminate the exit plane and collimate the light along one axis in the forward direction. The cylindrical Fresnel lens is used to collimate the light along an orthogonal axis in the forward direction.