Projection System with Enhanced Brightness

Abstract

A digital display system, such as a projection system, utilizing image forming elements such as LCDs or other light valves with means to enhance display brightness which may include the use of at least two light sources, means to split light from the light sources into two polarizations, means to rotate the polarization of the light of one polarization so that it matches the polarization of the remainder of the light, all of the light then being directed towards the image forming elements, and the use of novel optical elements to collect a majority of the light emitted by the light sources and to re-direct that light so that it can be used by the display system.

1 . An electronic display system comprising:
 a light source;   at least one element wherein an image may be formed thereon; and   at least one of:   a second light source,   at least one optical element to separate light into different polarizations which illuminate the at least one element wherein an image may be formed thereon, and   optical means to direct light emanating in multiple directions from at least one light source within the said electronic display system to the said at least one element wherein an image may be formed thereon.   
     
     
         2 . The electronic display system of  claim 1  wherein the at least one element wherein an image may be formed thereon comprises at least one light valve. 
     
     
         3 . The electronic display system of  claim 1  wherein the at least one element wherein an image may be formed thereon comprises three light valves. 
     
     
         4 . The electronic display system of  claim 1  wherein the at least one element wherein an image may be formed thereon comprises at least one LCD. 
     
     
         5 . The electronic display system of  claim 1  wherein the at least one element wherein an image may be formed thereon comprises three LCDs. 
     
     
         6 . The electronic display system of  claim 1  which includes at least two light sources. 
     
     
         7 . The electronic display system of  claim 6  which also includes means to direct light from the said at least two light sources to the said at least one element wherein an image may be formed thereon. 
     
     
         8 . The electronic display system of  claim 1  wherein the at least one optical element to separate light into different polarizations comprises at least one of:
 a dielectric coating, 
 a liquid crystal layer, and 
 a hologram. 
 
     
     
         9 . The electronic display system of  claim 1  which also includes means to rotate the polarization of one of the said different polarizations of light to match the other of the said different polarizations. 
     
     
         10 . The electronic display system of  claim 9  which also includes means to direct light of the un-rotated polarization and the light of the matching rotated polarization to the said at least one element wherein an image may be formed thereon. 
     
     
         11 . The electronic display system of  claim 1  which uses projection. 
     
     
         12 . An electronic display system comprising:
 a light source;   at least one element wherein an image may be formed thereon; and   at least one of:   a second light source,   at least one optical element to separate light into different polarizations which illuminate the at least one element wherein an image may be formed thereon, and   optical means to direct light emanating in multiple directions from at least one light source within the said electronic display system to the said at least one element wherein an image may be formed thereon;   and which includes at least two light sources and means to direct light from the said at least two light sources to the said at least one element wherein an image may be formed thereon.   
     
     
         13 . An electronic display system comprising:
 a light source;   at least one element wherein an image may be formed thereon; and   at least one of:   a second light source,   at least one optical element to separate light into different polarizations which illuminate the at least one element wherein an image may be formed thereon, and   optical means to direct light emanating in multiple directions from at least one light source within the said electronic display system to the said at least one element wherein an image may be formed thereon;   wherein the at least one optical element to separate light into different polarizations comprises at least one of:   a dielectric coating,   a liquid crystal layer, and   a hologram;   wherein said electronic display system also includes means to rotate the polarization of one of the said different polarizations of light to match the other of the said different polarizations and also includes means to direct light of the un-rotated polarization and the light of the matching rotated polarization to the said at least one element wherein an image may be formed thereon.