| 摘要 |
PROBLEM TO BE SOLVED: To enable a whole screen to be observed with uniform brightness even when it is viewed from one observation point by forming the exit pupil of an image projection device to be rectangular and arranging it in parallel with the longitudinal direction of the individual lenses of a unidirectional lens array. SOLUTION: By the change of light quantity occurring by difference between the matching of the rear projection type screen and the pupil of a projector and an observing position, the state 10 of the pupil at the left end part of the screen, the state 11 of the pupil at the central part and the state 12 of the pupil at the right end part are shown. The exit pupil of an element lens is shown by a rectangle and the exit pupil of the projector is shown by a square. Then, a projection lens whose exit pupil is rectangular is used and the direction of one side of the rectangle of the exit pupil and the direction of the element lens of the unidirectional lens array becoming the screen surface on which an image is formed are adjusted so as to project and form the image. Thus, a light beam whose intensity is almost identical at both of the peripheral part and the central part of an observation area can be made to arrive at an observer. |
