Liquid crystal projector with condenser lenses for blue and green panels only or the red panel condenser lens focal length being largest

摘要

On the incident sides of the blue light modulating liquid crystal panel and the green light modulating liquid crystal panel, condenser lenses whose outer diameter is equal to or more than that of the two liquid crystal panels are disposed respectively. No condenser lens is disposed on the incident side of the red light modulating liquid crystal panel. The focal length f of the two condenser lenses is preferably set to be a value ofPP(L.sub.1 ·L.sub.2) /(L.sub.1 +L. sub.2),P Pwhere L.sub.1 is the distance between each condenser lens and the light source, and L.sub.2 is the distance between each condenser lens and the projection lens. The direct light from the discharge lamp and incident upon the condenser lenses is all incident upon the projection lens. Alternatively, a condenser lens may be disposed on the incident side of the red light modulating liquid crystal, but having a focal length which is longer than the other condenser lenses, preferably equal to L.sub.1. Therefore, an image on a screen is improved in illuminance difference between the central portion and the peripheral portion and at the same time, luminance balance of the three single color lights is improved and color shade is reduced.