Projection type display

• US 5,765,934 A
• Filed: 07/31/1996
• Issued: 06/16/1998
• Est. Priority Date: 08/04/1995
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kida, Hiroshi, Daijogo, Akira, Shikama, Shinsuke, Okamori, Shinji, Toide, Eiichi
• Primary Examiner(s): DOWLING, WILLIAM C
• Application Number:
  US08/690,670
• Time in Patent Office: 685 Days
• Field of Search: 353/38, 353/37, 353/102, 353/121, 353/122, 353/94, 353/98, 353/99, 359/42, 359/894, 359/639, 359/640, 359/638, 362/32, 362/308, 362/234, 362/244, 362/245, 362/297, 362/299, 349/61, 349/62, 349/63, 349/67, 349/5, 385/901
• US Class Current: 353/94
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298
• CPC Class Codes: G03B 21/2013 Plural light sources
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10
• CPC Class Codes: H04N 9/3147 Multi-projection systems displays in general H04N9/12; video walls G06F3/1446, G09G2300/026
• CPC Class Codes: H04N 9/315 Modulator illumination systems general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20
• CPC Class Codes: H04N 9/3164 using multiple light sources

Abstract

In a light source apparatus for use with a projection type display, at least one light source is provided for emitting light. A reflector is provided correspondingly to the light source in order to gather the light emitted from the light source into a small area to form a converged luminous flux. A light guide has at least one light input section into which the luminous flux is coupled. The light input section is provided correspondingly to the light source. The light guide combines the luminous flux received through the light input sections into a single beam of luminous flux. The light-guide has at least one light output section from which said luminous flux is output. The light source apparatus may also include light-refracting element provided between the reflector and the light-guide. The light-refracting element receives the converged luminous flux from the reflector to refract the converged luminous flux so as to couple the converged luminous flux, as a uniform luminous flux, into the light-guide.

Claims

1. A light source apparatus for use with a projection type display comprising:

at least one light source for emitting light;

reflecting means provided correspondingly to said light source, said reflecting means directing the light emitted from said light source into a small area to form a converged luminous flux;

redistributing means for receiving said converged luminous flux and outputting a uniform luminous flux; and

light-guiding means for guiding said uniform luminous flux therethrough, said light-guiding means having at least one light input section into which said uniform luminous flux is coupled, said light input section being provided correspondingly to said light source, and said light-guiding means combining the uniform luminous flux coupled into said light input section into a single beam of luminous flux, said light-guiding means having at least one light output section from which said single beam of luminous flux is output.

2. The light source apparatus according to claim 1, wherein said redistributing means includes light-refracting means provided between said reflecting means and said light-guiding means, said light-refracting means receiving the converged luminous flux from said reflecting means and varying an angle of divergence of the converged luminous flux so as to couple uniform luminous flux into said light-guiding means.

3. The light source apparatus according to claim 1, wherein said light-guiding means is a reflecting mirror for reflecting the converged luminous flux to combine the converged luminous flux into a single beam of luminous flux.

4. The light source apparatus according to claim 1, wherein said light-guiding means is a reflecting surface of a prism for reflecting the converged luminous flux to combine the converged luminous flux into a single beam of luminous flux.

5. A projection type display comprising:

at least one light source for emitting light;

reflecting means provided correspondingly to said at least one light source, said reflecting means gathering the light emitted from said light source into a small area to form a converged luminous flux;

redistributing means for receiving the converged luminous flux and outputting a uniform luminous flux;

light-guiding means for guiding said uniform luminous flux therethrough, said light-guiding means having at least one light input section into which said uniform luminous flux is coupled, said light input section being provided correspondingly to said light source, and said light-guiding means combining the uniform luminous flux transmitted through the light input section into a single beam of luminous flux, said light-guiding means having at least one light output section from which said combined luminous flux is output;

at least one light valve for forming an image; and

projection lens for projecting an image from said light valve.

6. The projection type display according to claim 5, wherein said redistributing means includes:

light-refracting means provided between said reflecting means and said light-guiding means, said light-refracting means receiving the converged luminous flux from said reflecting means and varying an angle of divergence of the converged luminous flux so as to couple uniform luminous flux into said light-guiding means.

8. The light source apparatus according to claim 5, wherein said reflecting means is an elliptic mirror having an ellipsoidal surface of revolution centered on an optical axis thereof and having first and second focal points on the optical axis, said light-refracting means is of a cone shape located in the vicinity of said second focal point.

9. The light source apparatus according to claim 5, wherein said light-guiding means is any one of:

an optical fiber where a hollow cylindrical cladding is filled with any one of a transparent gel-like medium, transparent liquid medium, transparent glass medium, and transparent polymer medium, the cylindrical cladding having a refractive index smaller than that of the medium filling the cladding;

a bundle of element optical fibers randomly arranged both in a first plane through which the light is incident on the fibers and in a second plane through which the light exits the fibers so that there is no correlation between arrangements of the fibers in said first and second planes; and

a molded plastics or a molded rubber.

17. The light source apparatus according to claim 5, wherein said light-guiding means has a single light output section and as many light input sections as there are light sources, and the luminous flux coupled into said light input sections is combined into said single light output section.

19. The light source apparatus according to claim 5, wherein said reflecting means is an orthogonal parabolic reflector having a paraboloid of revolution centered on an optical axis thereof and having a focal point on the optical axis, said light-refracting means is of a cone shape located in the vicinity of said focal point.

7. A projection type display comprising:

at least one light source for emitting light;

reflecting means provided correspondingly to said light source, said reflecting means converging the light emitted from said light source into converged luminous flux;

light-guiding means for guiding said luminous flux therethrough, said light-guiding means having at least one light input section into which said luminous flux is coupled, said light input section being provided correspondingly to said light source, and said light-guiding means combining the luminous flux coupled into said light input section into one output beam of luminous flux, said light-guiding means having at least one light output section from which said luminous flux after having been combined is output;

at least one light valve for forming an image;

projection lens for projecting an image from said light valve; and

cone-shaped light-refracting means provided between said reflecting means and said light-guiding means so that the converged luminous flux enters a flat surface of the cone and exits an inclined surface of the cone so as to couple the converged luminous flux into said light-guiding means.

10. The projection type display according to claim 7, further including:

first lens means located between said light input section and said refracting means, said first lens means coupling the luminous flux refracted by said light-refracting means into said light-guiding means; and

second lens means located between said light-guiding means and said light valve, said second lens means having a focal point located between said second lens means and said light output section, said second lens means being positioned such that said luminous flux exits said light output section at a position upstream or downstream of said focal point.

11. The projection type display according to claim 10, further including a plurality of light valves, as many second lenses as there are light valves, and as many projection lenses as there are light valves, wherein said light-guiding means has as many light output sections as there are light valves.

12. The projection type display according to claim 10, further including a plurality of light sources, as many first lenses as there are light sources, and as many reflectors as there are light sources, wherein said light-guiding means has as many light input sections as there are light sources.

13. A light source apparatus for use with a projection type display comprising:

a plurality of light sources for emitting light;

a plurality of reflecting means provided correspondingly to said light sources, each of said light reflecting means converging the light emitted from a corresponding light source into converged luminous flux;

a plurality of reflecting mirrors provided correspondingly to said reflecting means, said reflecting mirrors reflecting corresponding converged luminous flux so as to combine the luminous flux from said reflecting mirrors into one output beam.

14. A light source apparatus for use with a projection type display, comprising:

a plurality of light sources emitting light;

a plurality of reflecting means provided correspondingly to said light sources, each of said reflecting means converging the light emitted from a corresponding light source into converged luminous flux;

a prism having a plurality of reflecting surfaces, the reflecting surface reflecting a corresponding converged luminous flux so as to combine the converged luminous flux from said reflecting means into one output beam.

15. A light source apparatus for use with a projection type display, comprising:

at least one light source for emitting light;

reflecting means provided correspondingly to said light source, said reflecting means converging the light emitted from said light source into converged luminous flux;

light-guiding means for guiding said luminous flux therethrough, said light-guiding means having at least one light input section into which said luminous flux is coupled, said light input section being provided correspondingly to said light source, and said light-guiding means combining the luminous flux coupled into said light input section into one beam of luminous flux, said light-guiding means having at least one light output section from which said luminous flux after having been combined is output; and

cone-shaped light-refracting means provided between said reflecting means and said light-guiding means so that the luminous flux from said reflecting means enters a flat surface of the cone and exits an inclined surface of the cone, the luminous flux exiting the inclined surface subsequently entering said light input section of said light-guiding means.

16. The light source apparatus according to claim 15, further including:

a first lens located between said light input section and said refracting means, said first lens coupling the converged luminous flux refracted by said light-refracting means into said light-guiding means; and

a second lens located downstream of said light-guiding means, said second lens having a focal point located between said second lens and said light output section, said second lens being positioned such that said single beam of luminous flux exits said light output section at a position upstream or downstream of said focal point.

18. A light source apparatus for use with a projection type display comprising:

at least one light source for emitting light;

reflecting means provided correspondingly to said light source, said reflecting means gathering the light emitted from said light source into a small area to form a converged luminous flux;

light-guiding means for guiding said luminous flux therethrough, said light-guiding means having at least one light input section into which said luminous flux is coupled, said light input section being provided correspondingly to said light source, and said light-guiding means combining the luminous flux coupled into said light input section into a single beam of luminous flux, said light-guiding means having at least one light output section from which said single beam of luminous flux is output;

light-refracting means provided between said reflecting means and said light-guiding means, said light-refracting means receiving the converged luminous flux from said reflecting means for refracting converged luminous flux so as to couple the converged luminous flux into said light-guiding means;

a first lens located between said light input section and said refracting means, said first lens coupling the converged luminous flux refracted by said light-refracting means into said light-guiding means; and

a second lens located downstream of said light-guiding means, said second lens having a focal point located between said second lens and said light output section, said second lens being positioned such that single beam of luminous flux exits said light output section at a position upstream or downstream of said focal point.

20. A light source apparatus for use with a projection type display comprising:

at least one light source for emitting light;

an elliptic mirror having an ellipsoidal surface of revolution centered on an optical axis thereof and having first and second focal points on the optical axis provided correspondingly to said light source, said elliptic mirror gathering the light emitted from said light source into a small area to form a converged luminous flux;

light-guiding means for guiding said luminous flux therethrough, said light-guiding means having at least one light input section into which said luminous flux is coupled, said light input section being provided correspondingly to said light source, and said light-guiding means combining the luminous flux coupled into said light input section into a single beam of luminous flux, said light-guiding means having at least one light output section from which said single beam of luminous flux is output; and

light-refracting means provided between said reflecting means and said light-guiding means, said light-refracting means receiving the converged luminous flux from said reflecting means for refracting converged luminous flux so as to couple the converged luminous flux into said light-guiding means, said light-refracting means being a cone shape located in the vicinity of said second focal point of said elliptic mirror.

21. A light source apparatus for use with a projection type display comprising:

at least one light source for emitting light;

an elliptic mirror having an ellipsoidal surface of revolution centered on an optical axis thereof and having first and second focal points on the optical axis provided correspondingly to said light source, said light source being located in the vicinity of said first focal point of said elliptic mirror, said elliptic mirror gathering the light emitted from said light source into a small area to form a converged luminous flux; and

light-guiding means for guiding said luminous flux therethrough, said light-guiding means having at least one light input section into which said luminous flux is coupled, said light input section being provided correspondingly to said light source, and said light-guiding means combining the luminous flux coupled into said light input section into a single beam of luminous flux, said light-guiding means having at least one light output section from which said single beam of luminous flux is output.

22. The light source apparatus according to claim 21, wherein said light source is a high voltage discharge lamp having a light-emitting portion positioned between said first and second focal points, and away from said first focal point by a distance in the range of two to three millimeters.

23. A light source apparatus for use with a projection type display comprising:

at least one light source for emitting light;

reflecting means provided correspondingly to said light source, said reflecting means gathering the light emitted from said light source into a small area to form a converged luminous flux, wherein said reflecting means is an orthogonal parabolic reflector having a paraboloid of revolution centered on an optical axis thereof, said paraboloid being given by Equations (1) and (2),

space="preserve" listing-type="equation">Y=2{f(f+X)}.sup.1/2 where -f≦

X≦

0 Eq. (1)

space="preserve" listing-type="equation">Y=2{f(f-X)}.sup.1/2 where 0≦

X≦

f Eq. (2)

where f is a focal length of the paraboloid located on X-axis of a coordinate (X, Y); and

light-guiding means for guiding said luminous flux therethrough, said light-guiding means having at least one light input section into which said luminous flux is coupled, said light input section being provided correspondingly to said light source, and said light-guiding means combining the luminous flux coupled into said light input section into a single beam of luminous flux, said light-guiding means having at least one light output section from which said single beam of luminous flux is output.

24. A light source apparatus for use with a projection type display comprising:

at least one light source for emitting light, said at least one light source including a plurality of lamps, all of which are glowing at the same time;

reflecting means provided correspondingly to said light source, said reflecting means gathering the light emitted from said light source into a small area to form a converged luminous flux; and

light-guiding means for guiding said luminous flux therethrough, said light-guiding means having at least one light input section into which said luminous flux is coupled, said light input section being provided correspondingly to said light source, and said light-guiding means combining the luminous flux coupled into said light input section into a single beam of luminous flux, said light-guiding means having at least one light output section from which said single beam of luminous flux is output.

25. A light source apparatus for use with a projection type display comprising:

at least one light source for emitting light, said at least one light source including a plurality of lamps, one of which is glowing at a time;

reflecting means provided correspondingly to said light source, said reflecting means gathering the light emitted from said light source into a small area to form a converged luminous flux; and

light-guiding means for guiding said luminous flux therethrough, said light-guiding means having at least one light input section into which said luminous flux is coupled, said light input section being provided correspondingly to said light source, and said light-guiding means combining the luminous flux coupled into said light input section into a single beam of luminous flux, said light-guiding means having at least one light output section from which said single beam of luminous flux is output.