Led backlight apparatus and method

Abstract

Backlit video display systems where the backlights (for example, LED backlights) are controlled based at least in part on the content of the video signal of the video that is being displayed by the backlit video display system. The system can provide specific control of the three primary colors (for example, red, green and blue LEDs). The system can content-based control in a spatial mode. The system a smart backlighting system with content-based controls at the following levels: (i) spectral, (ii) spatial, and (iii) temporal control. Also, some embodiments may provide a novel way of providing a backlit video display system with night vision (NV) capability through a unique four LED chip architecture.

1 . A backlight assembly comprising:
 a plurality of backlights;   a backlight supporting member;   and   a control system;   wherein:   the plurality of backlights are spaced apart on and mechanically connected to the backlight supporting member over a plurality of backlight locations;   the backlights located at each backlight location include a backlight set;   each backlight set comprises a first backlight, a second backlight and a third backlight, the first, second and third backlight of each backlight set has a different primary color of a set of primary colors; and   the control system is structured, connected and/or programmed to:
 be in data communication with each of the plurality of backlights, 
 receive a video signal representing video content, 
 control respective operation the plurality of backlights so that the backlights of each backlight set is independently controlled based, at least in part, on the video content of the video signal with respect to at least one of the following control parameters: (i) spectral control, (ii) spatial control, and/or (iii) temporal control. 
   
     
     
         2 . The assembly of  claim 1  wherein the control system is further structured, connected and/or programmed to control respective operation the plurality of backlights so that the backlights of each backlight set is independently controlled based, at least in part, on the video content of the video signal with respect to spectral control. 
     
     
         3 . The assembly of  claim 1  wherein the control system is further structured, connected and/or programmed to control respective operation the plurality of backlights so that the backlights of each backlight set is independently controlled based, at least in part, on the video content of the video signal with respect to spatial control. 
     
     
         4 . The assembly of  claim 1  wherein the control system is further structured, connected and/or programmed to control respective operation the plurality of backlights so that the backlights of each backlight set is independently controlled based, at least in part, on the video content of the video signal with respect to temporal control. 
     
     
         5 . The assembly of  claim 1  wherein the control system is further structured, connected and/or programmed to control respective operation the plurality of backlights so that the backlights of each backlight set is independently controlled based, at least in part, on the video content in a spatial mode. 
     
     
         6 . The assembly of  claim 1  wherein the plurality of backlights are structured, located, connected and/or controlled to be capable of producing a luminance greater than 350 fL. 
     
     
         7 . The assembly of  claim 1  wherein the plurality of backlights are structured, located, connected and/or controlled to be capable of producing a luminance of at least approximately 400 fL. 
     
     
         8 . The assembly of  claim 1  wherein for each set of backlights:
 the first backlight is in the blue range; 
 the second backlight is in the green range; and 
 the third backlight is in the red range. 
 
     
     
         9 . The assembly of  claim 1  further comprising an active matrix liquid crystal display device structured, located, sized, connected and/or shaped to be backlit by the plurality of backlights. 
     
     
         10 . The assembly of  claim 1  wherein each backlight of the plurality of backlights includes a light emitting diode. 
     
     
         11 . A backlight assembly comprising:
 a plurality of backlights;   a backlight supporting member;   and   a control system;   wherein:   the plurality of backlights are spaced apart on and mechanically connected to the backlight supporting member over a plurality of backlight locations;   the backlights located at each backlight location include a backlight set;   each backlight set comprises a first backlight, a second backlight, third backlight and a fourth backlight;   the first, second and third backlight of each backlight set has a different primary color of a set of primary colors;   the fourth backlight of each set of backlights has the same primary color as the third backlight, but has a different characteristic wavelength within the range of the primary color of the third backlight of its set; and   the control system is structured, connected and/or programmed to:
 be in data communication with each of the plurality of backlight, and 
 independently and selectively control the third and fourth backlights of each backlight set in a manner depending upon depending up a predetermined display mode. 
   
     
     
         12 . The assembly of  claim 11  wherein the control system is further structured, connected and/or programmed to selectively control the plurality of backlights at any given time according to one the following two display modes: regular and night vision. 
     
     
         13 . The assembly of  claim 12  wherein:
 for each set of backlights:
 the first backlight is in the blue range, 
 the second backlight is in the green range, 
 the third backlight is in the red range, 
 the fourth backlight is in the red range and has a shorter characteristic wavelength than the third backlight; and 
 
 the control system is further structured, connected and/or programmed to use the third backlight of each backlight set when operating in regular display mode and use the fourth backlight of each backlight set when operating in normal mode. 
 
     
     
         14 . The assembly of  claim 11  wherein the characteristic wavelength of the fourth backlight is a wavelength that will not substantially interfere with the gain wavelengths of night vision viewing equipment. 
     
     
         15 . The assembly of  claim 11  wherein each backlight of the plurality of backlights includes a light emitting diode. 
     
     
         16 . A backlight assembly for use in a backlit video display device with the backlit video display defining a display window, the assembly comprising:
 a plurality of backlights; and   a backlight supporting member;   wherein:   the plurality of backlights are spaced apart on and mechanically connected to the backlight supporting member over a plurality of backlight locations;   the backlights located at each backlight location include a backlight set;   each backlight set comprises at least one backlight(s);   the at least one backlight(s) of each backlight set is capable of producing, in the aggregate, white light; and   the backlight sets are located on the backlight supporting member so that at least one backlight set will be outside of the display footprint when the backlight assembly is installed in the backlit video display device.   
     
     
         17 . The assembly of  claim 16  further comprising an active matrix liquid crystal display device structured, located, sized, connected and/or shaped to be backlit by the plurality of backlights. 
     
     
         18 . The assembly of  claim 16  wherein each backlight of the plurality of backlights includes a light emitting diode. 
     
     
         19 . The assembly of  claim 16  wherein:
 the plurality of backlight locations are arranged as a regular rectangular two dimension matrix being characterized by linear rows and linear columns; 
 two rows of the matrix of backlight locations are outside of the footprint of the display window; and 
 two columns of the matrix of backlight locations are outside of the footprint of the display window. 
 
     
     
         20 . A backlight assembly comprising:
 a plurality of backlights;   a backlight supporting member;   and   a control system;   wherein:   the plurality of backlights are spaced apart on and mechanically connected to the backlight supporting member over a plurality of backlight locations;   the control system is connected in data communication with each backlight;   the control system is structured, connected and/or programmed to control the operation of each backlight of the plurality of backlights;   the control system comprises a watchdog module;   the watchdog module comprises a hardware mechanism; and   the watchdog module is structured, connected and/or programmed to periodically check the status of the control system.