Automatic convergence for image projection systems

Abstract

Systems and methods are provided that facilitate automatic convergence and geometry alignment in projection systems. Preferably, an optical element such as a lens array is coupled to all areas of the projection system's screen and to a detector element such as a photocell array. In operation, each lens of the lens array is adapted to map an individual portion or region of the screen onto the photocell array. A microprocessor, controller or the like uses the data output from the photocells to instruct an alignment controller to center or steer the beams to compensate for convergence error at a particular location. In a center alignment mode, four (4) or more beacon dots located about the periphery of the screen are detected to determine screen size and position, which is used to center the video image and the centers of the mapped regions on the screen.

1 . A process of aligning an image on a screen comprising the steps of 
 detecting the position of a plurality of beacon dots located about the periphery of a first mirror,    calculating an error measurement corresponding to the difference between the detected position of each of the plurality of beacon dots and the expected position of each of the plurality of beacon dots, and    adjusting the orientation of a second mirror in accordance with the error measurement.    
     
     
         2 . The process of  claim 1  wherein the adjusting step includes moving the second mirror about one or more axes.  
     
     
         3 . The process of  claim 1  wherein the detecting steps includes 
 displaying patterns of light across an imaging area of a projection system,    deflecting the patterns from the second mirror to the general area of the first mirror, and    sensing a difference in reflected light when the pattern of light are displayed on a beacon dot of the plurality of beacon dots.    
     
     
         4 . The process of  claim 1  further comprising the steps of 
 detecting the position of a plurality of beacon dots located about the periphery of a display screen,    calculating an error measurement corresponding to the difference between the detected position of each of the plurality of beacon dots about the periphery of the display screen and the expected position of each of the plurality of beacon dots, and    adjusting the orientation of the first and second mirrors in accordance with the error measurement.    
     
     
         5 . The process of  claim 4  wherein the adjusting step includes moving the first and second mirrors about one or more axes.  
     
     
         6 . The process of  claim 4  wherein the detecting steps includes 
 displaying patterns of light across an imaging area of a projection system,    deflecting the patterns from the second mirror to the first mirror,    deflecting the patterns from the first mirror to the general area of the display screen, and    sensing a difference in reflected light when the patterns of light are displayed on a beacon dot of the plurality of beacon dots.    
     
     
         7 . A projection system comprising, 
 a screen,    a projection unit optically coupled to a first mirror,    a second mirror optically coupled to the first mirror and the screen, and    a detection system optically coupled to the screen, the detection system comprising an optical element and a detector element.    
     
     
         8 . The projection system of  claim 7  further comprising first and second positioning systems coupled to the first and second mirrors, respectively.  
     
     
         9 . The projection system of  claim 8  wherein the first and second positioning systems comprise one or more linear actuators.  
     
     
         10 . The projection system of  claim 9  further comprising a plurality of beacon dots located about the periphery of the second mirror.  
     
     
         11 . The projection system of  claim 10  further comprising a plurality of beacon dots located about the periphery of the display screen.  
     
     
         12 . A projection system comprising, 
 a display screen,    a projection unit,    first and second mirrors adjustably mounted within an enclosure and optically coupled to the projection unit and display screen,    a plurality of beacon dots positioned about the periphery of the screen and the second mirror, and    a detection system optically coupled to the first and second mirrors, the screen and the plurality of beacon dots.    
     
     
         13 . The projection system of  claim 12  further comprising first and second position adjustment systems coupled to the first and second mirrors.  
     
     
         14 . The projection system of  claim 13  wherein the first and second positioning systems comprise one or more linear actuators.