Mask and method for making full color display

Abstract

Pixels for organic light emitting full color display panels are made by simultaneously depositing red, green, and blue dopants such that the blue dopant is dispersed in at least one non-blue subpixel. Method relates to using a shadow mask (which may be removable) comprising ribs which, in an angled evaporation method, can correct for parallax.

1 . A removable mask for making an organic light emitting full color display panel by angled evaporation, the mask comprising a series of ribs that define slots in which individual pixels are built.  
     
     
         2 . The mask of  claim 1  wherein the height of the ribs is approximately equal to the width of the pixels of the display panel.  
     
     
         3 . The mask of  claim 1  wherein the mask comprises crystalline material, metal, or polymer.  
     
     
         4 . The mask of  claim 3  wherein the crystalline material is the silicon.  
     
     
         5 . The mask of  claim 1  wherein the pitch of the ribs is smaller than the pitch of the pixels for which the mask will be used.  
     
     
         6 . A method of making organic light emitting pixels having red, green, and blue subpixels on a display panel comprising: 
 for each pixel, depositing a hole transporting layer and an electron transporting layer; and    depositing red, green, and blue dopants simultaneously in a host layer such that the blue dopant is deposited on the blue subpixel and at least one of the red and green subpixels.    
     
     
         7 . The method of  claim 6  wherein the host layer is the hole transporting layer.  
     
     
         8 . The method of  claim 6  wherein the host layer is the electron transporting layer.  
     
     
         9 . The method of  claim 6  wherein the host layer is a layer between the hole transporting layer and electron transporting layer.  
     
     
         10 . The method of  claim 6  wherein a shadow mask is used during the deposition process.  
     
     
         11 . The method of  claim 10  wherein the mask is removable.  
     
     
         12 . The method of  claim 11  wherein the removable mask is reusable.  
     
     
         13 . The method of  claim 10  wherein the mask is integrated with the display panel.  
     
     
         14 . The method of  claim 13  wherein the integrated mask comprises photoresist.  
     
     
         15 . The method of  claim 10  wherein the red and green dopant sources are located on opposite sides of the display at an angle of about 20° to about 70° from the pixel surfaces and the blue dopant source and other sources are located in a plane that bisects the display panel substrate and is normal to a straight line connecting the red and green dopant sources.  
     
     
         16 . The method of  claim 6  wherein the deposition paths of the red and green dopants are shielded from each other and the other sources wherein the shielding starts at the red and green dopant sources and extends some distance toward the pixel.  
     
     
         17 . A method of correcting for parallax in the making of an organic light emitting display panel comprising using line-of-sight vapor deposition to create a series of adjacent pixels, each pixel comprising sub-pixels, wherein one or more source is positioned at an angle of about 20° to about 70° from the pixel surfaces and wherein a shadow mask is used in the deposition process, the mask having slots defined by ribs wherein the pitch of the ribs is smaller than the pitch of the pixels.  
     
     
         18 . The method of  claim 17  wherein the mask is removable.  
     
     
         19 . The method of  claim 18  wherein the mask is reusable.  
     
     
         20 . The method of  claim 17  wherein the mask is integrated with the display panel.