Light source unit and projection type video display apparatus using the same
First Claim
1. A light source unit for use in a projection type video display apparatus having a video display device for modulating light on the basis of a video signal and a projection lens for projecting output light emitted from said video display device upon a screen, comprising:
- at least two arrayed light sources; and
a focusing mirror in the form of a reflector disposed in correspondence with each of said light sources and having a shape of paraboloid or non-spherical form approximating the paraboloid, wherein when D represents an effective diameter of said reflector, f represents a focal distance of said mirror and Z represents a distance between a light emitter of said light source and an apex at a center of said mirror, said light source unit is so constructed as to satisfy
D<
4×
f or D<
4×
Z.
7 Assignments
0 Petitions
Accused Products
Abstract
In a projection type video display apparatus, in order to assure sufficient brightness by suppressing a decrease in light utilization efficiency inside a limited output aperture area of a light source unit, a transmission or reflection type liquid crystal is used for a video display device and the light source unit having a plurality of reflectors or focusing mirrors in correspondence with LED'"'"'s representing light sources is so constructed as to satisfy D<4×f or D<4×Z, where D represents an effective diameter of a reflector, f represents a focal distance of a mirror and Z represents a distance between a light emitter of the light source and an apex at a center of the mirror.
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Citations
8 Claims
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1. A light source unit for use in a projection type video display apparatus having a video display device for modulating light on the basis of a video signal and a projection lens for projecting output light emitted from said video display device upon a screen, comprising:
-
at least two arrayed light sources; and
a focusing mirror in the form of a reflector disposed in correspondence with each of said light sources and having a shape of paraboloid or non-spherical form approximating the paraboloid, wherein when D represents an effective diameter of said reflector, f represents a focal distance of said mirror and Z represents a distance between a light emitter of said light source and an apex at a center of said mirror, said light source unit is so constructed as to satisfy
D<
4×
f or D<
4×
Z. - View Dependent Claims (2)
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3. A light source unit for use in a projection type video display apparatus having a video display device for modulating light on the basis of a video signal and a projection lens for projecting output light emitted from said video display device upon a screen, comprising:
-
at least two arrayed light sources; and
a focusing mirror in the form of a reflector disposed in correspondence with each of said light sources and having a shape of paraboloid or non-spherical form approximating the paraboloid, wherein when D represents an effective diameter of said reflector, f represents a focal distance of said mirror and Z represents a distance between a light emitter of said light source and an apex at a center of said mirror, said light source unit is so constructed as to satisfy
1.6×
f<
D<
3.2×
f or 1.6×
Z<
D<
3.2×
Z. - View Dependent Claims (4)
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5. A projection type video display apparatus comprising:
-
a light source unit;
a video display device which modulates luminous flux from said light source unit on the basis of a video signal; and
a projection lens which projects output light from said video display device upon a screen, wherein said light source unit includes at least two arrayed light sources and a focusing mirror in a form of a reflector disposed in correspondence with each of said light sources and having a shape of paraboloid or non-spherical form approximating the paraboloid, and wherein when D represents an effective diameter of said reflector, f represents a focal distance of said mirror and Z represents a distance between a light emitter of said light source and an apex at a center of said mirror, said light source unit is so constructed as to satisfy
D<
4×
f or D<
4×
Z. - View Dependent Claims (6)
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7. A projection type video display apparatus comprising:
-
a light source unit;
a video display device which modulates luminous flux from said light source unit on the basis of a video signal; and
a projection lens which projects output light from said video display device upon a screen, wherein said light source unit includes at least two arrayed light sources and a focusing mirror in a form of a reflector disposed in correspondence with each of said light sources and having a shape of paraboloid or non-spherical form approximating the paraboloid, and wherein when D represents an effective diameter of said reflector, f represents a focal distance of said mirror and Z represents a distance between a light emitter of said light source and an apex at a center of said mirror, said light source unit is so constructed as to satisfy
1.6×
f<
D<
3.2×
f or 1.6×
z<
D<
3.2×
Z. - View Dependent Claims (8)
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Specification