Being the catoptrics component which possesses the reflecting interface which is formed the illumination adjustment manner in image display optical unit

摘要

PROBLEM TO BE SOLVED: To eliminate trouble that unconformity between an illumination area and the picture plane size of a picture display element and irregular illumination are caused when the position of the illumination area is changed by varying the tilt angle of a catoptric element. SOLUTION: This picture display optical unit is provided with the catoptric elements respectively having a reflection surface constituted of a curved surface, that is, the 1st catoptric element 81 (81a) reflecting illuminating light from a light source, the 2nd catoptric element 82 reflecting the illuminating light reflected by the 1st catoptric element, and the 3rd catoptric element 81 (81b) reflecting the illuminating light reflected by the 2nd catoptric element and guiding it to the picture display element 10R. The 1st and the 3rd catoptric elements are moved in directions (X and Y directions) where change concerning the shape and the brightness of an irradiation area by the illuminating light on the picture display element is not caused substantially with respect to the 2nd catoptric element, so that the position of the irradiation area on the picture display element is adjusted.