Light recycler and color display system including same

• US 20050225866A1
• Filed: 02/25/2005
• Published: 10/13/2005
• Est. Priority Date: 06/10/2003
• Status: Active Grant

• Current Assignee: Nayef M. Abu-Ageel
• Original Assignee: Nayef M. Abu-Ageel
• Inventors: Abu-Ageel, Nayef M.
• Granted Patent: US 7,475,992 B2
• Time in Patent Office: Days
• US Class Current: 359/619
• CPC Class Codes: G02B 26/008 in the form of devices for effecting sequential colour changes, e.g. colour wheels
• CPC Class Codes: G02B 27/0994 Fibers, light pipes optical fibers per se G02B6/02
• CPC Class Codes: G02B 6/0096 the lights guides being of the hollow type
• CPC Class Codes: G02B 6/06 the relative position of the fibres being the same at both ends, e.g. for transporting images
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/136 by etching
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time
• 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

Abstract

A light recycler for use in color projection display systems. The light recycler redirects light reflected by a color wheel of the projection system to increase the light output of the projection system. The light recycler is capable of setting the desired numerical aperture of the light source beam, as well as providing the desired spatial distribution of light in terms of intensity and angle. This improves the light uniformity and brightness of the image displayed by the projection system, and improves the efficiency of the system. The light recycler includes at least one substantially planar optical element array receiving the non-uniform light from the light source. The optical element array includes an optically transmissive substrate and a plurality of optical micro-elements formed in the substrate. The micro-elements act together to produce an output light beam having a desired cross-sectional area and spatial distribution of light intensity and angle.

Claims

1. A light recycler for use in a color projection system, comprising:

a substantially planar optical element array for receiving light emitted from a light source, the optical element array including an optically transmissive substrate and a plurality of optical micro-elements formed in the substrate.

2. The light recycler of claim 1, wherein the optical element array splits the input light from the light source into a plurality of superimposing sub-beams to produce a substantially uniform distribution of output light across the exit aperture of the light recycler.

3. The light recycler of claim 1, wherein the optical micro-elements are selected from the group consisting of lenses, prisms, tunnels, optical waveguides, and any suitable combination of the foregoing.

4. The light recycler of claim 1, wherein the micro-elements are separated from each another by air or a material having a lower refractive index than the micro-elements.

5. The light recycler of claim 1, further comprising a light pipe aligned along the same optical axis with the optical element array.

6. The light recycler of claim 1, further comprising a reflective plate aligned along the same optical axis with the optical element array.

7. The light recycler of claim 6, wherein the optical element array is included in the reflective plate.

8. A light recycler for use in a color projection system, comprising:

a substantially planar two-dimensional circulation optical element array having a plurality of optical elements formed and positioned in a predetermined arrangement on at least one surface of the circulation optical element array, for circulating input light within the light recycler; and

a substantially planar two-dimensional extraction optical element array having a plurality of optical elements formed and positioned in a predetermined arrangement on at least one surface of the extraction optical element array, for extracting circulating light from the light recycler.

9. The light recycler of claim 8, further comprising:

a substantially planar two-dimensional collimation optical element array having a plurality of optical elements formed and positioned in a predetermined arrangement on at least one surface of the collimation optical element array, for collimating the extracted light.

10. The light recycler of claim 9, wherein the collimation optical element array includes a plurality of micro-prisms.

11. The light recycler of claim 8, wherein the circulation optical element array and the extraction optical element array are formed on two substantially parallel surfaces of a single optically transmissive planar substrate.

12. A color projection system, comprising:

a light source emitting substantially non-uniform light in terms of intensity and angle;

a light recycler comprising at least one substantially planar optical element array receiving the non-uniform light from the light source, the optical element array including an optically transmissive substrate and a plurality of optical micro-elements formed in the substrate, the light recycler producing an output light beam of predetermined cross-sectional area and predetermine spatial distribution of light intensity and angle;

means for producing plural color light beams from the light output of the light recycler; and

at least one modulator for modulating the plural color light beams to produce an output image.

13. The color projection system of claim 12, wherein the producing means includes a color wheel.

14. The color projection system of claim 12, further comprising:

a lens selected from the group consisting of a focusing lens, a projection lens, and a combination of the foregoing.

15. The color projection system of claim 12, further comprising a screen.

16. The color projection system of claim 12, wherein the light recycler includes:

a reflective plate, receiving the non-uniform light from the light source and including the optical element array; and

a light pipe aligned along the same optical axis with the reflective plate and receiving light output from the optical element array.

17. The color projection system of claim 16, wherein the light recycler further comprises a second substantially planar optical element array aligned along the same optical axis with the reflective plate and light pipe, receiving light output from the light pipe.

18. The color projection system of claim 12, wherein the light recycler includes:

a substantially planar two-dimensional circulation optical element array having a plurality of optical elements formed and positioned in a predetermined arrangement on at least one surface of the circulation optical element array, for circulating input light within the light recycler; and

a substantially planar two-dimensional extraction optical element array having a plurality of optical elements formed and positioned in a predetermined arrangement on at least one surface of the extraction optical element array, for extracting circulating light from the light recycler.

19. The light recycler of claim 18, further comprising:

a substantially planar two-dimensional collimation optical element array having a plurality of optical elements formed and positioned in a predetermined arrangement on at least one surface of the collimation optical element array, for collimating the extracted light.

20. The light recycler of claim 18, wherein the circulation optical element array and the extraction optical element array are formed on two substantially parallel surfaces of a single optically transmissive planar substrate.