Centrifugal illumination system

DETAILED DESCRIPTION An object of the present invention is, therefore, to provide an illumination system.
Another object of this invention is to provide such an illumination system with improved illumination uniformity.
A further object of this invention is to provide such an illumination system with improved illumination efficiency.
Yet another object of this invention is to provide such an illumination system with a shortened optical path length.
The present invention includes an image display illumination system having an illumination homogenizer, such as a reflective tunnel homogenizer, and a centrifugal relay lens system that receives illumination from a light source and directs the illumination toward an image source such as an LCD.
The illumination homogenizer efficiently provides uniform distribution of light over a region matched to the configuration of the LCD image source.
The centrifugal relay lens system includes, for example, an S-curve aspheric lens surface that functions to increase the illumination distribution toward the edges and corners of the image source and away from the center, thereby emphasizing marginal illumination relative to central illumination.
A second aspheric surface sharply images illumination light toward the image source over a short distance while counteracting pin cushion distortion with the converse barrel distortion.
As a result, the projection system of the present invention provides illumination with improved uniformity and efficiency while also providing a shortened optical path length.
Illumination systems according to the present invention are suitable for use in a wide variety of illumination applications including direct lighting and transmissive and reflective image display systems.
The foregoing and other features and advantages of preferred embodiments of the present invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.