DISPLAY DEVICE AND ITS OPTICAL DEVICE, LIGHT SOURCE UNIT

摘要

PROBLEM TO BE SOLVED: To provide an illumination optical system which is high in the efficiency of utilizing the light from a light source, is small in size and high in performance and a liquid crystal display device which is bright, small in size and is good in performance by using the illumination optical system. SOLUTION: This illumination optical system is provided with a first concave face mirror 2 which has an effect of reflecting the light emitted from a light source 1 and directing the light toward a surface 5 to be irradiated and a second concave face mirror 3 which changes the direction of the light emitted from the light source 1 and not reflected by the first concave face mirror 2 so as to reflect the light by the concave face mirror 2. The liquid crystal display device using the illumination optical system is provided with a microlens array which consists of unit lens parts corresponding to each one pixel of the pixel array of liquid crystals and has the same array as the pixel array of the liquid crystals in tight contact with the surface on the side where the light radiated from the light source of the liquid crystal element is made incident.