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OwnerKenichiro Yoshioka, Michiko Torigoe +1inventors
InventorsKenichiro Yoshioka, Michiko Torigoe, Kouchi Tanaka
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The invention provides a method for improving the contrast ratio of the display image projected on a screen from a liquid crystal projector that comprises at least a light source, an electrode-having, twisted nematic liquid crystal cell comprising at least one nematic liquid crystal, and two polarizers disposed so that the liquid crystal cell is sandwiched between them, which is characterized in that at least two HBLC optical films are so arrayed between the polarizers that the slow axes of the films are approximately perpendicular to each other so as not to cause a retardation in the direction normal to the film surfaces; and provides a liquid crystal projector that uses the improving method.
A method for improving the contrast ratio of the display image projected on a screen from a liquid crystal projector that comprises at least a light source, an electrode-having, twisted nematic liquid crystal cell (hereinafter referred to as a TN liquid crystal cell), and two polarizers disposed so that the liquid crystal cell is sandwiched between them, which is characterized in that at least two, hybrid-oriented liquid crystal layer-having optical films (hereinafter referred to as HBLC optical films) are so arrayed between the polarizers that the slow axes of the films are approximately perpendicular to each other so as not to cause a retardation in the direction normal to the film surfaces.
An optical system for improving the contrast ratio of the display image projected on a screen from a liquid crystal projector, which has a TN liquid crystal cell and at least two HBLC optical films between polarizers and which is characterized in that the films are so arrayed that their slow axes are approximately perpendicular to each other so as not to cause a retardation in the direction normal to the film surfaces.
A composite optical film for contrast ratio improvement, which comprises at least a pair of HBLC optical films and a pair of PLLC optical films.
Dependencies are inferred from the claim text.