| 摘要 |
An optical illumination system (10, 60, 70, 80, 100, 110, 120) producing a light beam (28) having uniform illumination over a rectangular or non-symmetrical area. An array of light emitting elements (24, 102) generate light which is condensed to a single focal point F, such as by an aspheric (42) or achromatic (104, 106) lens. A holographic diffuser (16) diffuses this light, and a cylindrical lens (18) vertically compresses the light. The light output from the condensing lens is very near the sum of the light output from the individual light emitting elements. The light emitting elements can be LEDs (24) arc lamps or incandescent lamps (102). With any attenuation in light intensity from the light emitting elements (24, 102), the entire light beam (28) output is reduced uniformly, with no localized image plane degradation being generated. The present invention finds use in printing engines, such as those for xerographic printers, and display systems such as projectors and televisions.
|
