Light recapture projection system

Abstract

A projection system is disclosed comprising a light source, a first reflector proximate the light source, a second reflector proximate the light source, a light pipe, a color sequencing device a spatial light modulator and a target. The color sequencing device preferably directs three or more colors onto the spatial light modulator at a time. Some light is reflected from the color sequencing device back through the light pipe and is again reflected at the reflector at the light source before returning to the light pipe and color sequencing device. The brightness of the projection system is thereby increased.

I claim:  
     
         1 . A projection system, comprising: 
 a point source of light and a reflector proximate to the point source of light;    a color sequencer,    wherein the point source of light, reflector and color sequencer are arranged such that the light from the point source of light is directed so as to be incident on the color sequencer, and wherein at least 10% of the light that is reflected back from the color sequencer impinges on the reflector proximate to the point source of light and is reflected back so as to again be incident on the color sequencer.    
     
     
         2 . The projection system of  claim 1 , wherein at least 20% of the light that is reflected back from the color sequencer impinges on the reflector proximate to the point source of light and is reflected back so as to again be incident on the color sequencer.  
     
     
         3 . The projection system of  claim 2 , wherein at least 30% of the light that is reflected back from the color sequencer impinges on the reflector proximate to the point source.  
     
     
         4 . The projection system of  claim 1 , wherein the point source of light is an arc lamp.  
     
     
         5 . The projection system of  claim 4 , wherein the reflector is a spherical reflector proximate the arc lamp.  
     
     
         6 . The projection system of  claim 5 , wherein the spherical reflector is a reflective coating on the glass bulb of the arc lamp.  
     
     
         7 . The projection system of  claim 5 , further comprising first optics disposed between the arc lamp and the color sequencer, wherein the first optics is positioned for focusing light from the arc lamp and reflector proximate to the arc lamp onto the color sequencer.  
     
     
         8 . The projection system of  claim 7 , further comprising a light pipe positioned between the first optics and the color sequencer.  
     
     
         9 . The projection system of  claim 5 , further comprising a light valve disposed to receive multi colored light from the light sequencer.  
     
     
         10 . The projection system of  claim 9 , wherein the color sequencer is capable of forming a spatial and temporal sequence of colors that are incident on the light valve.  
     
     
         11 . The projection system of  claim 9 , further comprising second optics for focusing light from the color sequencer onto the light valve.  
     
     
         12 . The projection system of  claim 9 , further comprising third optics for projection light from the light valve onto a target.  
     
     
         13 . The projection system of  claim 1 , wherein the color sequencer is a color wheel, drum, cone or color selective panel.  
     
     
         14 . The projection system of  claim 9 , wherein the color sequencer is a color wheel capable of passing multiple colors onto the light valve at the same time.  
     
     
         15 . The projection system of  claim 1 , wherein the light valve is a micromirror array.  
     
     
         16 . The projection system of  claim 1 , further comprising a second reflector facing said reflector and disposed to direct light to the color sequencer.  
     
     
         17 . The projection system of  claim 16 , further comprising a light pipe.  
     
     
         18 . The projection system of  claim 17 , wherein said reflector is a spherical reflector.  
     
     
         19 . The projection system of  claim 18 , wherein the second reflector is an elliptical reflector.  
     
     
         20 . The projection system of  claim 16 , wherein light reflected from the color sequencer is incident on both said reflector and said second reflector so as to be again directed on the color sequencer.  
     
     
         21 . A projection system, comprising: 
 an arc lamp;    a spherical reflector proximate to the arc lamp;    a color sequencer;    wherein the arc lamp, spherical reflector and color sequencer are arranged in the projection system such that the light from the arc lamp is directed so as to be incident on the color sequencer, and wherein at least a portion of light that is reflected back from the color sequencer impinges on the spherical reflector so as to reflected and again be incident on the color sequencer.    
     
     
         22 . The projection system of  claim 21 , wherein at least 20% of the light that is reflected back from the color sequencer impinges on the spherical reflector proximate to the arc lamp and is reflected back so as to again be incident on the color sequencer.  
     
     
         23 . The projection system of  claim 22 , wherein at least 30% of the light that is reflected back from the color sequencer impinges on the spherical reflector proximate to the arc lamp.  
     
     
         24 . The projection system of  claim 21 , wherein the arc lamp is a UHP burner.  
     
     
         25 . The projection system of  claim 24 , wherein the spherical reflector is a reflective layer on the arc lamp.  
     
     
         26 . The projection system of  claim 25 , wherein the spherical reflector is a reflective coating on the glass bulb of the arc lamp.  
     
     
         27 . The projection system of  claim 26 , further comprising first optics disposed between the arc lamp and the color sequencer, wherein the first optics is positioned for focusing light from the arc lamp and spherical reflector proximate to the arc lamp onto the color sequencer.  
     
     
         28 . The projection system of  claim 27 , further comprising a light pipe positioned between the first optics and the color sequencer.  
     
     
         29 . The projection system of  claim 25 , further comprising a light valve disposed to receive multi colored light from the light sequencer.  
     
     
         30 . The projection system of  claim 29 , wherein the color sequencer is capable of forming a spatial and temporal sequence of colors that are incident on the light valve.  
     
     
         31 . The projection system of  claim 29 , further comprising second optics for focusing light from the color sequencer onto the light valve.  
     
     
         32 . The projection system of  claim 9 , further comprising third optics for projection light from the light valve onto a target.  
     
     
         33 . The projection system of  claim 21 , wherein the color sequencer is a color wheel, drum, cone or color selective panel.  
     
     
         34 . The projection system of  claim 29 , wherein the color sequencer is a color wheel capable of passing multiple colors onto the light valve at the same time.  
     
     
         35 . The projection system of  claim 21 , wherein the light valve is a micromirror array.  
     
     
         36 . The projection system of  claim 21 , further comprising a second reflector facing said spherical reflector and disposed to direct light to the color sequencer.  
     
     
         37 . The projection system of  claim 16 , further comprising a light pipe.  
     
     
         38 . The projection system of  claim 37 , wherein said reflector is a spherical mirror element disposed adjacent to the arc lamp.  
     
     
         39 . The projection system of  claim 38 , wherein the second reflector is an elliptical reflector.  
     
     
         40 . The projection system of  claim 36 , wherein light reflected from the color sequencer is incident on both said spherical reflector and said second reflector so as to be again directed on the color sequencer.  
     
     
         41 . A projection system, comprising: 
 a UHP lamp having a dichroic coating;    a color sequencer;    wherein the UHP lamp with dichroic coating and color sequencer are arranged in the projection system such that the light from the UHP lamp is directed so as to be incident on the color sequencer, and wherein at least a portion of light that is reflected back from the color sequencer impinges on the dichroic coating so as to reflected and again be incident on the color sequencer.    
     
     
         42 . The projection system of  claim 41 , wherein at least 10% of the light that is reflected back from the color sequencer impinges on the dichroic coating of the UHP lamp and is reflected back so as to again be incident on the color sequencer.  
     
     
         43 . The projection system of  claim 42 , wherein at least 30% of the light that is reflected back from the color sequencer impinges on the dichroic coating of the UHP lamp.  
     
     
         44 . The projection system of  claim 41 , wherein the UHP lamp has an arc gap of 1 mm or less.  
     
     
         45 . The projection system of  claim 44 , wherein the dichroic coating forms a spherical reflective surface.  
     
     
         46 . The projection system of  claim 45 , wherein the spherical reflector is a reflective coating on the glass bulb of the UHP lamp.  
     
     
         47 . The projection system of  claim 46 , further comprising first optics disposed between the UHP lamp and the color sequencer, wherein the first optics is positioned for focusing light from the UHP lamp and spherical reflector proximate to the UHP lamp onto the color sequencer.  
     
     
         48 . The projection system of  claim 47 , further comprising a light pipe positioned between the first optics and the color sequencer.  
     
     
         49 . The projection system of  claim 45 , further comprising a light valve disposed to receive multi colored light from the light sequencer.  
     
     
         50 . The projection system of  claim 49 , wherein the color sequencer is capable of forming a spatial and temporal sequence of colors that are incident on the light valve.  
     
     
         51 . The projection system of  claim 49 , further comprising second optics for focusing light from the color sequencer onto the light valve.  
     
     
         52 . The projection system of  claim 9 , further comprising third optics for projection light from the light valve onto a target.  
     
     
         53 . The projection system of  claim 41 , wherein the color sequencer is a color wheel, drum, cone or color selective panel.  
     
     
         54 . The projection system of  claim 49 , wherein the color sequencer is a color wheel capable of passing multiple colors onto the light valve at the same time.  
     
     
         55 . The projection system of  claim 41 , wherein the light valve is a micromirror array.  
     
     
         56 . The projection system of  claim 41 , further comprising a second reflector facing said spherical reflector and disposed to direct light to the color sequencer.  
     
     
         57 . The projection system of  claim 56 , further comprising a light pipe.  
     
     
         58 . The projection system of  claim 57 , wherein said reflector is a spherical mirror element disposed adjacent to the UHP lamp.  
     
     
         59 . The projection system of  claim 58 , wherein the second reflector is an elliptical reflector.  
     
     
         60 . The projection system of  claim 56 , wherein light reflected from the color sequencer is incident on both said spherical reflector and said second reflector so as to be again directed on the color sequencer.  
     
     
         61 . A light collecting system comprising 
 a color filter element; and    a concentrated light source illuminating a color filter element;    wherein a substantial portion of light that does not pass through said color filter element is reflected back to said light source, and subsequently is reflected back to said color filter element and then passes through a different location of said color filter element with a 10% or less change in the etendue of the system.    
     
     
         62 . The light collecting system of  claim 61 , wherein the light source is a high temperature gas plasma.  
     
     
         63 . An optical system comprising: 
 a multi spectral light source;    a reflector at the light source for reflecting light from the light source;    a color sequencing device disposed to receive light from the reflector and that spatially passes some colors and reflects others back to the reflector,    wherein at least 60% of the light that is reflected from the color sequencing device is directed back onto the reflector at the light source.    
     
     
         64 . The optical system of  claim 63 , wherein a light tunnel is provided between the light source and color sequencing device.  
     
     
         65 . The optical system of  claim 64 , further comprising a second reflector disposed to reflect light from the light source back through the light source and to the color sequencing device via the reflector.  
     
     
         66 . The optical system of  claim 65 , wherein the second reflector lowers the etendue of the optical system.  
     
     
         67 . The optical system of  claim 63 , wherein the reflector is an elliptical reflector.  
     
     
         68 . The optical system of  claim 65 , wherein the second reflector is spherical reflector.  
     
     
         69 . The optical system of  claim 68 , wherein the second reflector is a coating on the light source, the light source being an arc lamp.  
     
     
         70 . The optical system of  claim 65 , wherein the second reflector is an elliptical reflector.  
     
     
         71 . The optical system of  claim 63 , wherein the light source is an arc lamp having an arc length of 1 mm or less.  
     
     
         72 . The optical system of  claim 63 , wherein the reflector is a spherical reflector.  
     
     
         73 . The optical system of  claim 65 , further comprising a third reflector that reflect light into the light tunnel that exits the light tunnel but is not directed to said reflector.  
     
     
         74 . The optical system of  claim 65 , wherein the light tunnel does not have a restricted opening.  
     
     
         75 . The optical system of  claim 65 , wherein light is recycled back to the reflector while conserving etendue.  
     
     
         76 . The optical system of  claim 63 , further comprising focusing optics for focusing light from the color sequencing device on the light valve.  
     
     
         77 . The optical system of  claim 76 , further comprising projection optics for projecting an image from the light valve onto a target.  
     
     
         78 . The optical system of  claim 63 , wherein at least 70% of the light that is reflected from the color sequencing device is directed back onto the reflector at the light source.  
     
     
         79 . The optical system of  claim 78 , wherein at least 80% of the light that is reflected from the color sequencing device is directed back onto the reflector at the light source.  
     
     
         80 . A projection system, comprising: 
 a light source and a reflector proximate to the light source;    a color sequencer,    wherein the light source, reflector and color sequencer are arranged such that the light from the light source is directed so as to be incident on the color sequencer, and wherein at least 10% of the light that is reflected back from the color sequencer is recycled via the light source by being incident on the reflector proximate to the light source and is reflected back so as to again be incident on the color sequencer, and wherein the etendue of the projection system is less than 20% different from a system without light being recycled via the light source.    
     
     
         81 . The projection system of  claim 80 , wherein the etendue is less than 10% different from a system without light being recycled via the light source.  
     
     
         82 . A projection system, comprising: 
 a light source and a reflector proximate to the light source;    a spatial light modulator;    a color sequencer that provides three or more different colors onto the spatial light modulator at the same time;    wherein the light source, reflector and color sequencer are arranged such that the light from the light source is directed so as to be incident on the color sequencer, and wherein at least 60% of the light that is reflected back from the color sequencer to be incident on the reflector proximate to the light source and is reflected back so as to again be incident on the color sequencer.    
     
     
         83 . The projection system of  claim 82 , wherein at least 70% of the light that is reflected back from the color sequencer to be incident on the reflector proximate to the light source and is reflected back so as to again be incident on the color sequencer.  
     
     
         84 . The projection system of  claim 83 , wherein at least 80% of the light that is reflected back from the color sequencer to be incident on the reflector proximate to the light source and is reflected back so as to again be incident on the color sequencer  
     
     
         85 . A projection system, comprising: 
 a light source and a reflector proximate to the light source;    a spatial light modulator;    a color sequencer that provides three or more different colors onto the spatial light modulator at the same time;    wherein the light source, reflector and color sequencer are arranged such that the light from the light source is directed so as to be incident on the color sequencer and has a first etendue, and wherein light reflected back from the color sequencer is incident on the reflector proximate to the light source and is reflected back so as to again be incident on the color sequencer with a second etendue less than 20% different from the first etendue.    
     
     
         86 . The projection system of  claim 85 , wherein the second etendue less than 10% different from the first etendue.