Electronic displays using optically pumped luminescent semiconductor nanocrystals

Abstract

A multicolor electronic display is based on an array of luminescent semiconductor nanocrystals. Nanocrystals which emit light of different colors are grouped into pixels. The nanocrystals are optically pumped to produce a multicolor display. Different sized nanocrystals are used to produce the different colors. A variety of pixel addressing systems can be used.

1 - 20 . (canceled)  
   
   
       21 . A multicolor display apparatus, comprising: 
 an array of semiconductor nanocrystals forming a pixel array of different colors, wherein the sizes of the nanocrystals determine the colors; and    a pixel addressing system operatively associated with the nanocrystal array for selectively optically exciting the nanocrystals to produce a luminescent color pattern of pixels.    
   
   
       22 . The apparatus of  claim 21  wherein the pixel addressing system includes a backlight source.  
   
   
       23 . The apparatus of  claim 22  wherein the backlight source is a source of ultraviolet light or blue light.  
   
   
       24 . The apparatus of  claim 22  wherein the pixel addressing system comprises a multielement backlight source, wherein each source element is independently operable.  
   
   
       25 . The apparatus of  claim 22  wherein the backlight source comprises source elements including LEDs or semiconductor lasers.  
   
   
       26 . The apparatus of  claim 22  wherein the backlight source comprises source elements comprising sources of ultraviolet light or blue light.  
   
   
       27 . The apparatus of  claim 21  wherein the pixel addressing system comprises: 
 a backlight source; and    a liquid crystal modulator positioned between the backlight source and the nanocrystal array.    
   
   
       28 . The apparatus of  claim 27  further comprising an analyzer between the nanocrystal array and liquid crystal modulator.  
   
   
       29 . The apparatus of  claim 27  further comprising an analyzer positioned between the backlight source and liquid crystal modulator.  
   
   
       30 . A method comprising: 
 providing a transparent panel;    forming an array of pixels on the panel, wherein the array of pixels comprises a first discrete pixel comprising first nanocrystal particles of a first size and a second discrete pixel comprising second nanocrystal particles of a second size; and    providing a pixel addressing system operatively associated with the array of pixels, wherein the pixel addressing system is adapted to excite the first nanocrystal particles in the first discrete pixel using light comprising a wavelength to cause the first pixel to produce a first color and to excite the second nanocrystal particles in the second discrete pixel using light of the same wavelength to cause the second discrete pixel to produce a second color.    
   
   
       31 . The apparatus of  claim 30  wherein the pixel addressing system includes a light source that produces only one wavelength of light.  
   
   
       32 . The apparatus of  claim 30  wherein the pixel addressing system includes a backlight source and a liquid crystal modulator.  
   
   
       33 . The apparatus of  claim 30  wherein forming the array of pixels comprises depositing the first nanocrystal particles and the second nanocrystal particles on the panel.  
   
   
       34 . The apparatus of  claim 30  further comprising providing a long pass filter in operative association with the array of pixels.  
   
   
       35 . A method comprising: 
 forming an array of semiconductor nanocrystals forming a pixel array of different colors on a panel, wherein the sizes of the nanocrystals determine the colors; and    providing a pixel addressing system operatively associated with the nanocrystal array for selectively optically exciting the nanocrystals to produce a luminescent color pattern of pixels.    
   
   
       36 . The apparatus of  claim 35  wherein the pixel addressing system includes a light source that produces only one wavelength of light.  
   
   
       37 . The apparatus of  claim 35  wherein the pixel addressing system includes a backlight source and a liquid crystal modulator.  
   
   
       38 . The apparatus of  claim 35  wherein forming the array comprises depositing the nanocrystals on the panel.  
   
   
       39 . The apparatus of  claim 35  further comprising providing a long pass filter in operative association with the array of pixels.  
   
   
       40 . A multicolor display apparatus comprising: 
 a pixel array comprising at least first and second individually addressable pixels of different colors, the at least first pixel comprising a plurality of nanocrystals of a first size and the at least second pixel comprising a plurality of nanocrystals of a second size different from said first size, wherein the different sizes of the nanocrystals determine the different colors;    a pixel addressing system operatively associated with the pixel array for selectively optically exciting the nanocrystals in the first and second pixels.    
   
   
       41 . The apparatus of  claim 40  wherein the pixel addressing system includes a backlight source.  
   
   
       42 . The apparatus of  claim 41  wherein the backlight source is a source of ultraviolet light or blue light.  
   
   
       43 . The apparatus of  claim 41  wherein the pixel addressing system comprises a multielement backlight source, wherein each source element is independently operable.  
   
   
       44 . The apparatus of  claim 41  wherein the backlight source comprises source elements including LEDs or semiconductor lasers.  
   
   
       45 . The apparatus of  claim 41  wherein the backlight source comprises source elements comprising sources of ultraviolet light or blue light.