Projection image display device including optical system

Abstract

A projection image display device includes: laser diodes which emit excitation light; a top-hat diffusing element which diffuses and provides the excitation light with a top-hat intensity distribution; a phosphor which emits light when illuminated by the excitation light diffused by the top-hat diffusing element; an integrator rod which homogenizes the light emitted by the phosphor; DMDs which modulate the light homogenized by the integrator rod; and a projector which projects the light modulated by the DMDs.

What is claimed is: 
     
       1. A projection image display device comprising:
 a laser light source which emits excitation light;   a top-hat diffusing element which diffuses and provides the excitation light with a top-hat intensity distribution;   a light emitter which emits light when illuminated by the excitation light diffused by the top-hat diffusing element;   a light homogenization element which homogenizes an intensity distribution of the light emitted by the light emitter;   a light modulating element which modulates the light whose intensity distribution has been homogenized by the light homogenization element; and   a projector which projects, as an image, the light modulated by the light modulating element, wherein   the top-hat diffusing element diffuses and provides the excitation light with the top-hat intensity distribution having an emission pattern which is rectangular in shape,   the light homogenization element is an integrator rod utilizing internal reflections of the light from the light emitter to homogenize the intensity distribution of the light, and   the integrator rod has an entrance face which is rectangular in shape.   
     
     
       2. The projection image display device according to  claim 1 , wherein
 an aspect ratio of the entrance face is generally identical to an aspect ratio of the emission pattern.   
     
     
       3. The projection image display device according to  claim 1 , comprising
 at least two light-source devices each including the laser light source, the top-hat diffusing element, and the light emitter, wherein   the light homogenization element is an integrator rod having an entrance face which is rectangular in shape,   light emitted by the at least two light-source devices enter a plurality of regions of the entrance face, the plurality of regions being rectangular in shape, and   aspect ratios of the plurality of regions are generally identical to an aspect ratio of the emission pattern.   
     
     
       4. The projection image display device according to  claim 1 , wherein
 the light homogenization element is a pair of fly-eye lenses, and   an aspect ratio of each of cells of the pair of fly-eye lenses is generally identical to an aspect ratio of the emission pattern.   
     
     
       5. The projection image display device according to  claim 1 , further comprising
 a lens which condenses the excitation light diffused by the top-hat diffusing element to convert the top-hat intensity distribution for an angle imparted to the diffused excitation light into a positional intensity distribution, wherein   the light emitter emits light when illuminated by the excitation light diffused by the top-hat diffusing element and condensed by the lens.   
     
     
       6. A projection image display device comprising:
 a laser light source including first and second light source units, which emits excitation light, wherein the first light source unit emits a part of the excitation light in a first direction, and the second light source unit emits another part of the excitation light in a second direction different from the first direction;   a top-hat diffusing element which diffuses and provides the excitation light with a top-hat intensity distribution, the excitation light from the laser light source being directed from a mirror to the top-hat diffusing element;   a light emitter which emits light when illuminated by the excitation light diffused by the top-hat diffusing element;   a light homogenization element which homogenizes an intensity distribution of the light emitted by the light emitter;   a light modulating element which modulates the light having intensity distribution homogenized by the light homogenization element; and   a projector which projects, as an image, the light modulated by the light modulating element,   wherein the excitation light partially separated by the mirror is reflected and diffused on a light path between the mirror and the light homogenization element and merged with the light from the light emitter;   wherein the top-hat diffusing element diffuses and provides the excitation light with the top-hat intensity distribution having an emission pattern which is rectangular in shape,   wherein the light homogenization element is an integrator rod utilizing internal reflections of the light from the light emitter to homogenize the intensity distribution of the light, and   wherein the integrator rod has an entrance face which is rectangular in shape.   
     
     
       7. The projection image display device according to claim 6, wherein the top-hat diffusing element includes a plurality of micro lenses. 
     
     
       8. The projection image display device according to claim 7, wherein each of the plurality of micro lenses has an area of 1 mm 2  or less. 
     
     
       9. The projection image display device according to claim 6, wherein
 the excitation light partially separated by the mirror is part of light from the first light source unit, and   light from the second light source unit enters the light emitter.   
     
     
       10. The projection image display device according to claim 9, further comprising a diffuser configured to diffuse the excitation light partially separated by the mirror, wherein
 the diffused light from the diffuser is merged with the light from the light emitter, and   the integrator rod homogenizes the merged light.   
     
     
       11. The projection image display device according to claim 10, wherein
 the first light source unit comprises a plurality of laser light elements, and   a number of the laser light elements emitting light which is to enter the diffuser is less than a number of the laser light elements emitting light which is to enter the light emitter.   
     
     
       12. The projection image display device according to claim 6, wherein
 the merged light enters a plurality of regions of the entrance face, the plurality of regions being rectangular in shape, and   aspect ratios of the plurality of regions are generally identical to an aspect ratio of the emission pattern.   
     
     
       13. The projection image display device according to claim 6, further comprising a lens which condenses the excitation light diffused by the top-hat diffusing element to convert the top-hat intensity distribution for an angle imparted to the diffused excitation light into a positional intensity distribution, wherein
 the light emitter emits the light when illuminated by the excitation light diffused by the top-hat diffusing element and condensed by the lens.