High Luminance Projection Displays And Associated Methods

Abstract

Projection displays include a highlight projector and a main projector. Highlights projected by the highlight projector boost luminance in highlight areas of a base image projected by the main projector. Various highlight projectors including steerable beams, holographic projectors and spatial light modulators are described.

1 . A display system comprising:
 a main projector arranged to project an image defined by base image data onto a screen;   a highlight projector arranged to project a highlight image defined by highlight image data onto the screen in registration with the base image; and   a data processor configured to process image data to generate the highlight image data.   
     
     
         2 . A display system according to  claim 1  wherein the highlight projector is characterized by a peak luminance that exceeds a peak luminance of the main projector by at least a factor of 3. 
     
     
         3 . A display system according to  claim 1  wherein the highlight projector comprises a steerable light beam. 
     
     
         4 . A display system according to  claim 1  wherein the highlight projector comprises a holographic projector. 
     
     
         5 . A display system according to  claim 1  wherein image processor is configured to process the image data by identifying pixels in the image data for which luminance exceeds a first threshold. 
     
     
         6 . A display system according to  claim 5  wherein the image processor is configured to generate the highlight image such that no more than a predetermined number of pixels in the highlight image have luminance values exceeding a second threshold. 
     
     
         7 . A display system according to  claim 1  wherein the highlight projector comprises a light source that generates a beam of light, a beam steering device arranged to steer the beam and a controller connected to control the light source and the beam steering device to cause the beam to deliver illumination to one or more highlight areas in the highlight image. 
     
     
         8 . A display system according to  claim 7  wherein the beam steering device is arranged to steer the beam onto a location in a two-dimensional spatial light modulator and the light projector comprises a projection lens arranged to image the spatial light modulator onto a screen. 
     
     
         9 . A display system according to  claim 8  wherein the beam comprises a beam of white light. 
     
     
         10 . A display system according to  claim 8  wherein the beam comprises a laser beam. 
     
     
         11 . A display system according to  claim 1  wherein the light projector comprises a light redirecting projector. 
     
     
         12 . A display system according to  claim 1  wherein the main projector comprises a 2D spatial light modulator and the highlight projector is arranged to project the highlight image onto the spatial light modulator of the main projector. 
     
     
         13 . A display system according to  claim 12  comprising a controller configured to:
 estimate a distribution of light on the spatial light modulator the estimated distribution of light including a contribution from the highlight projector; and, control controllable elements of the spatial light modulator based at least in part on the image data and the estimated distribution of light. 
 
     
     
         14 . A display system according to  claim 1  wherein the highlight projector comprises a 2D spatial light modulator in an optical path and a controller and the controller is configured to set pixels of the 2D spatial light modulator to correct an image projected by the highlight projector to more accurately represent the highlight image. 
     
     
         15 . A highlight projector system comprising:
 an image processor configured to process image data to yield a highlight image;   a light projector operable to project light according to the highlight image in registration with a base image.   
     
     
         16 . A highlight projector system according to  claim 15  wherein the image processor is configured to process the image data by identifying pixels in the image data for which luminance exceeds a first threshold. 
     
     
         17 . A highlight projector system according to  claim 16  wherein the image processor is configured to generate the highlight image such that no more than a predetermined number of pixels in the highlight image have luminance values exceeding a second threshold. 
     
     
         18 . A highlight projector system according to  claim 17  wherein the light projector comprises a light source that generates a beam of light, a beam steering device arranged to steer the beam and a controller connected to control the light source and the beam steering device to cause the beam to deliver illumination to one or more highlight areas in the highlight image. 
     
     
         19 . A highlight projector system according to  claim 18  wherein the beam steering device is arranged to steer the beam onto a location in a two-dimensional spatial light modulator and the light projector comprises a projection lens arranged to image the spatial light modulator onto a screen. 
     
     
         20 . A highlight projector system according to  claim 19  wherein the highlight projector comprises a controller configured to set pixels of the two-dimensional spatial light modulator to correct an image projected by the highlight projector to more accurately represent the highlight image. 
     
     
         21 . A highlight projector system according to  claim 15  wherein the light projector comprises a light redirecting projector. 
     
     
         22 . A highlight projector according to  claim 21  wherein the light redirecting projector comprises a spatial phase modulator located at a Fourier plane in the light projector. 
     
     
         23 . A display comprising:
 a light source of spatially-modulated light arranged to illuminate a spatial light modulator wherein the source of spatially modulated light comprises a 2D holographic light source.   
     
     
         24 . A display according to  claim 23  wherein the 2D holographic light source comprises a phase modulator located at a Fourier plane in an optical system of the light source. 
     
     
         25 . A display according to  claim 24  comprising a controller configured to control the phase modulator according to image data such that the light source illuminates the spatial light modulator with an intensity that varies according to the image data. 
     
     
         26 . A display according to  claim 24  wherein the controller is configured to generate control signals for the phase modulator based at least in part on an inverse Fourier transform of the image data. 
     
     
         27 . A display according to  claim 24  wherein the controller is configured to estimate an intensity of light incident from the light source on pixels of the spatial light modulator and to generate control values for the spatial light modulator based on a comparison of the estimated light intensity and the image data. 
     
     
         28 . A display according to  claim 27  wherein the spatial light modulator comprises a transmissive light modulating panel. 
     
     
         29 . A display according to  claim 28  wherein the transmissive light modulating panel comprises a liquid crystal display panel. 
     
     
         30 . A method for displaying an image defined by image data, the method comprising:
 concentrating light from a light source to yield light that has been spatially-modulated in a manner based on the image data light;   illuminating a spatial light modulator with the spatially-modulated light; and   controlling the spatial light modulator to display an image according to the image data.   
     
     
         31 . A method according to  claim 30  wherein the light source comprises a source of coherent light and concentrating the light comprises adjusting phases of the light at a Fourier plane. 
     
     
         32 . A method for displaying an image according to image data, the method comprising:
 processing the image data to generate a base image and a highlight image comprising highlight pixels;   operating a main projector to display the base image; and   operating the highlight projector to display the highlight image superposed with the base image.   
     
     
         33 . A method according to  claim 32  wherein the base image is the same as the image data.