| 摘要 |
PURPOSE: An optical system of an LCD(Liquid Crystal Display) projector is provided to enhance the optical efficiency and uniformity of an optical system by setting the same optical path length of RGB(Red,Green,Blue). CONSTITUTION: An optical system of an LCD projector includes: second and third full-reflecting mirrors(42,44), a first polarizing film(50R) and a first PBSP(Polarizing Beam Split Prism,52R) arranged on an optical path between a first dichroic mirror(40) and a red LCD panel(54R); a third full-reflecting mirror(44), a second dichroic mirror(48), a second polarizing film(50G) and a second PBSP(52G) formed on an optical path between the first dichroic mirror and a green LCD panel(54G); a third polarizing film(50B) and a third PBSP(52B) mounted on an optical path between the second dichroic mirror and a blue LCD panel(54B); a dichroic prism(56) formed among the first to third PBSPs; and a projection lens(58) opposed to the beam transmission surface of the dichroic prism. The second and third full-reflecting mirrors emit red beam to the first polarizing film by full-reflecting the red beam from the first dichroic mirror. To prevent interference of the red beam path with the third full-reflecting mirror, the first dichroic mirror and the second full-reflecting mirror are arranged with proper angles. A fourth full-reflecting mirror(46) emits beam of the first dichroic mirror to the second dichroic mirror. The second dichroic mirror transmits green beam to the second polarizing film and blue beam to the third polarizing film. The first to third polarizing films transmit linearly-polarized beam to each PBSP. The first to third PBSPs reflect the linearly-polarized beam to the RGB LCD panels. The LCD panels display images by transmitting or reflecting the incident beam. Thereby, the optical efficiency and uniformity of RGB beam is enhanced. |
