An image display apparatus is provided with a screen having retro-reflectivity, a liquid crystal display device displaying an image, a projection optical system projecting the light of the liquid crystal display device onto the screen, and a beam magnifier located close to the screen and magnifying the...http://www.google.com.tw/patents/US6323999?utm_source=gb-gplus-share專利 US6323999 - Image display apparatus
