| 摘要 |
PROBLEM TO BE SOLVED: To attain optimized lighting for, specially, a liquid crystal display unit, etc., by providing a 1st and a 2nd group of lenses which are specific and widening the area of a beam carrying minimum energy over several lenses in the 1st group. SOLUTION: This lighting device includes the 1st group RL1 of lenses which converge light of a beam on a point or line of a 3rd plane and form a 2nd plane perpendicular to the direction of the beam, and the 2nd group of lenses, and the area of the beam carrying the minimum light energy is widened over several lenses in the 1st group RL1. This includes an optical integrator which receives the light beam from a light source and outputs a lighting beam to a screen. Of this device, the lamp S1 is positioned at the focus of a spherical reflector P2 of a concave type ellipse, parabola or sphere, and a hemispherical reflector P1 is provided preferably on the lamp S1 to reflect the light on the reflector P2. By this method, a part of 180 deg.<ψ<360 deg. of the liquid crystal screen is lightened with a removed incident light beam. |
