| 摘要 |
PURPOSE:To improve the luminance and the contrast of an enlarged image on a projection screen by increasing a luminous flux projected through the effective diameter of a projection optical system. CONSTITUTION:The device is provided with an image compressing means (CMP) for executing compression so that a fluorescent screen (PNL) of a projection type cathode ray tube (PRT), or a picture frame ratio of an original image formed on a liquid crystal panel(LCP) approaches '1', and an image expanding optical system (EXT) for expanding this original image so as to become a picture frame ratio of the original image. Accordingly, all luminous fluxes passing through the effective diameter of the projection optical system become maximum, and luminance and contrast of an enlarged image on a projection screen are improved. |
