| 摘要 |
<p>A bright, small, light-weight, high resolution and economical projection display having a relatively simple construction and four great features of oblique projection, uniform illumination, large depth of focus and magnifying short-distance projection. This display comprises an illumination unit (1), an image formation unit (2) and an image projection unit (3). The illumination unit (1) comprises an input angle control part group including a light source (1a) and at least one optical surface (1c) for receiving main beams emitted from the imaginary center of the light source (1a) and controlling its input cubic angle; and a luminous flux control part group including at least two optical surfaces, that is, the optical surface (1c) having mainly a spatial distribution control function of the main beams on an imaginary plane disposed transversely to the travelling direction of the main beams outgoing from the part group described above, and an optical surface (1d) having mainly a direction control function of the main beams by receiving the main beams from the optical surface (1c). The image formation unit (2) selectively reflects or transmits the luminous flux from the illumination unit (1), forms an original picture image, and does not greatly change the angle of divergence of the luminous flux contributing to the image formation in front and at back thereof. The image projection unit (3) receives the luminous flux outgoing from the image formation unit and forms a secondary picture image on a screen.</p> |
