| 摘要 |
PURPOSE:To obtain a clear video without hot spot on an enlarged and projected video by providing an optical central axis of a Fresnel lens at a position which is separated from a transmission type liquid crystal display(LCD) panel. CONSTITUTION:By arranging the transmission type LCD panel 3 and a plane mirror 4 under the Fresnel lens 2, incident light from a lamp house 1 becomes parallel to the perpendicular of the plane surface part of the lens 2 after it is passed through the lens 2. Besides, the reflected light of the mirror 4 also becomes parallel to the perpendicular. As the result, the video on the panel 3 can be excellently enlarged. Besides, by providing the optical central axis 5 of the lens 2 at the position which is separated from the panel 3, the bundle of rays which is directly reflected on a projection lens 6 is eliminated out of the incident light and the hot spots are not generated. |
