Compact, high-efficiency illumination system for video-imaging devices
View Patent ↗An illumination system for a video-imaging device has a light source and a collector of light from the light source. The collector is formed according to the principles of non-imaging optics and receives a portion of the light from the light source. The collector is configured to reduce the angular distribution of the collected light from the light source to match the requirements of a digital pixelation device.
1. An illumination system for a video-imaging device, comprising:
a) a light source; and
b) a collector of light from the light source; the collector being formed according to the principles of non-imaging optics and receiving a portion of the light from the light source;
c) the collector being configured to reduce the angular distribution of the collected light from the light source to match the requirements of a digital pixelation device;
d) the shape of the collector changing from substantially round at a collector inlet to substantially rectangular along the length of the collector towards a collector outlet, with the size of the collector chosen to optimize efficient coupling to a digital pixelation device.
2. The system of claim 1 , wherein the light source is a metal halide lamp.
3. The system of claim 1 , wherein the light source is a high pressure mercury lamp.
4. The system of claim 1 , wherein the light source is a Xenon lamp.
5. The system of claim 1 , wherein the light source is a Xenon-mercury lamp.
6. The system of claim 1 , wherein a portion of the light source not physically received in the collector has a coating to reflect visible light it receives towards the collector.
7. The system of claim 6 , wherein the coating is applied using low pressure chemical vapor deposition of titania and silica oxides.
8. The system of claim 6 , wherein the coating is applied using sputtering chemical vapor deposition of tantala and silica oxides.
9. The system of claim 6 , wherein where the coating is designed to pass ultraviolet and infrared radiation.
10. An illumination system for a video-imaging device, comprising:
a) a light source;
b) a collector of light from the light source; the collector being formed according to the principles of non-imaging optics, receiving a portion of the light from the light source, and having an outlet;
c) the collector being configured to reduce the angular distribution of the light collected from the light source to match the requirements of a digital pixelation device; and
d) a spatial distribution-averaging device with an input end and an output end, the input end receiving light from the collector and providing at an output end of the device an average of light received from the collector.
11. The system of claim 10 , wherein the spatial distribution-averaging device comprises a solid glass rod with a rectangular cross section along the length of the rod.
12. The system of claim 10 , wherein the spatial distribution-averaging device comprises a hollow glass rod with a rectangular cross section along the length of the rod.
13. The system of claim 10 , wherein the input end of the spatial distribution-averaging device is sized about the same as the outlet of the collector.
14. An illumination system for video-imaging devices, comprising:
a) lamp;
b) a first collector of light from the light source; the collector being formed according to the principles of non-imaging optics and receiving a portion of the light from the light source; and
c) a second collector of light from the light source; the collector being formed according to the principles of non-imaging optics and receiving a portion of the light from the light source;
d) a first part of the lamp protruding into the first collector, and a second part of the lamp protruding into the second collector; and
e) the collectors being designed to reduce the angular distribution of the light collected from the light source to match the requirements of a digital pixelation device.
15. The system of claim 14 , wherein the first and second parts of the lamp each comprise substantially a respectively different hemisphere of the lamp.
16. The system of claim 14 , wherein each of the two collectors is respectively optimized for a one or more different parts of the light spectrum.
17. The system of claim 14 , wherein the light source has a first thin film, reflective coating on the first part of the lamp, and a second thin film, reflective coating on the second part of the lamp.
18. The system of claim 17 , wherein the thin film reflective coating on the first part of the lamp reflects a particular range or ranges of the visible spectrum and the reflective coating on the second part of the lamp is transparent to the particular range or ranges of the visible spectrum.
19. The system of claim 17 , wherein the thin film reflective coating on the second part of the lamp reflects a particular part or parts of the visible spectrum and the reflective coating on the first part of the lamp is transparent to this particular part or parts of the visible spectrum.
20. An illumination system for video-imaging devices, comprising:
a) a light source having an arctube;
b) a first collector of light from the light source; the collector being formed according to the principles of non-imaging optics and receiving a portion of light from the light source;
c) a second collector of light from the light source; the second collector being formed according to the principles of non-imaging optics and receiving a portion of light from the light source; and
d) a third collector of light from the light source; the third collector being formed according to the principles of non-imaging optics and receiving a portion of the light from the light source;
e) said collectors being designed to reduce the angular distribution of the light to match the requirements of a digital pixelation device.
21. The system of claim 20 , wherein first, second and third portions of the arctube of the light source protrude into the first, second and third collectors, respectively.
22. The system of claim 21 , wherein the first, second and third portions each is substantially one-third of a circumference of the arctube of the light source with respect to a main longitudinal axis of the arctube.
23. The system of claim 21 , wherein the light source is coated with at least one thin film coating that reflects light in at least one range of the visible light spectrum and transmits light in at least another range.
24. The system of claim 23 , wherein:
a) the thin film coating on the first portion reflects blue and green light, but passes red light;
b) the thin film coating on the second portion reflects red and green light, but passes blue light; and
c) the thin film coating on the third portion reflects red and blue light, but passes green light.
25. The system of claim 23 , wherein a thin film coating on the first portion reflects and transmits different ranges of the visible light spectrum compared to thin film coatings on the second and third portions.
26. The system of claim 25 , wherein the thin film coatings on the first, second and third portions are designed so that the ranges of the visible light spectrum reflected by the thin film coatings on the first and second portions are transmitted by the thin film coatings on the third portion.
27. An illumination system for video-imaging devices, comprising:
a) a first light source to produce red light;
b) a first collector of light from the light source; the collector being formed according to the principles of non-imaging optics and receiving a portion of light from the first light source;
c) a second light source to produce green light;
d) a second collector of light from the second light source; the second collector being formed according to the principles of non-imaging optics and receiving a portion of light from the second light source;
e) a third light source to produce blue light; and
f) a third collector of light from the third light source; the third collector being formed according to the principles of non-imaging optics and receiving a portion of light from the third light source;
g) at least substantially one-third of a bulbous portion of the first, second and third light sources protruding into the first, second and third collectors, respectively;
h) each of the collectors being designed to set the angular distribution of the light they pass to match the requirements of a digital pixelation device.
28. The system of claim 27 , wherein the first, second and third light sources are optimized to produce red, green and blue light, respectively.
29. The system of claim 27 , wherein the light sources include at least one metal halide lamps.
30. The system of claim 27 , wherein the light sources include at least one light-emitting diode.
31. The system of claim 27 , wherein the cross-sectional shape of each collector changes from substantially round at an inlet to substantially rectangular at an outlet along the length of the collector, with the size of the collector chosen to optimize efficient coupling to a digital pixelation device.
32. The system of claim 27 , wherein the respective portions of the first, second and third light sources protruding into the first, second and third collectors, respectively, each comprise substantially a hemisphere of the respective light source.
33. The system of claim 27 , wherein the portion of each light source not protruding into a respective collector has thereon a respective coating for reflecting light of the same color produced by said each light source.
34. The system of claim 33 , wherein each respective coating is designed to pass any of:
a) ultraviolet and infrared radiation;
b) visible light which is outside of the desired color of light; and
c) ultraviolet and infrared radiation and visible light which is outside of the desired color of light.
35. The system of claim 27 , further comprising, for each collector:
a) a respective solid rod with a square cross section along the length of the rod;
b) the rod being positioned between a collector output and an input to a digital pixelation device; and
c) the rod providing light at an input to the digital pixelation device representing an average of light received from the collector output.
36. The system of claim 35 , wherein each of the solid rods has a coating that reflects light that is outside of the desired color range.
37. An illumination system for a video-imaging device, comprising:
a) a light source; and
b) a collector of light from the light source; the collector being formed according to the principles of non-imaging optics and receiving a portion of the light from the light source;
c) the collector being configured to reduce the angular distribution of the collected light from the light source to match the requirements of a digital pixelation device;
d) the shape of the collector changing from non-rectangular at a collector inlet, so as to match shape of an adjacent portion of the light source, to substantially rectangular along the length of the collector towards a collector outlet, with the size of the collector chosen to optimize efficient coupling to a digital pixelation device.