| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an illuminating device capable of reducing speckle noise generated when using semiconductor laser, and to provide a projection type image display device using the illuminating device. <P>SOLUTION: The illuminating device 1 is constituted of a light source 12 wherein a plurality of LD (laser diode) chips 11 .... are arranged, a lens cell 14 arranged on the light outgoing side of each LD chip 11, a pair of fly's eye lenses 13.... and a phase shift plate 15. The phase shift plate 15 is constituted of a plurality of planar transparent parts having different thickness arranged on the laser optical path of each LD chip 11. When the light is transmitted through the planar transparent part, the distance of the light is varied in proportion to the refractive index, and the distance of the light is also varied in accordance with the different thickness of each planar transparent part, then, the phase of the laser light transmitted through each planar transparent part is varied. then, the phases of the laser light beams of the LD chips 11 become mutually uneven. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
