P‐95: Fresnel Lenses in Rear Projection Displays
Arthur Davis, Robert C. Bush, John C. Harvey, Michael F. Foley · SID Symposium Digest of Technical Papers · 2001
Abstract A plastic Fresnel lens positioned just before the diffusion screen in a projection system can provide significantly superior corner illumination, enhancing overall display luminance uniformity. Fresnel lenses are also used within the light engine to collimate light through the LCD panel and focus light through the projection lens. Disadvantages include the added cost of the lenses, ghosting, printout of the Fresnel rings and moiré patterns. Birefringence is important to control in polarization‐sensitive applications. Without reduction of ghosting artifacts, Fresnel lenses will have limited application in text‐based RP systems. Ghosting is described in some detail including how it is caused, quantified and reduced. Efforts to reduce cost and birefringence will also be discussed.