Method and Apparatus for Compensating for Distortion in a Scanned Beam System

Abstract

A scanning system device has a predetermined aberration as it scans or switches light along selected optical paths. A deformable membrane receives the light and introduces an inverse “aberration” that offsets that of the scanning system. In one embodiment the scanning system includes a torsion arm that supports an oscillatory body. The torsion arm and/or body can be machined from metal, micromachined in silicon or formed in a variety of other ways. Alternatively, the scanning system may include a rotating polygonal scanner or other type of optical scanner. In another approach, an optical switch replaces the scanner.

1 . (canceled) 
   
   
       2 . A method for compensating for distortion in a scanned beam device comprising the steps of:
 scanning a beam of light across a field of view through a series of actual pixel locations;   for each actual pixel location identifying at least one desired pixel location corresponding to the actual pixel location;   wherein for at least one of the actual pixel locations, the corresponding at least one desired pixel location includes at least two corresponding desired pixel locations that differ in location from the actual pixel location due to distortion;   determining for each of the identified actual pixel locations that differs from at least two desired pixel locations due to distortion a corresponding set of weighted data as a function of the distortion and image data for the at least two desired pixel locations; and   modulating the beam of light according to the weighted data when the beam of light is aligned with the corresponding actual pixel location.   
   
   
       3 . The method of  claim 2  wherein the step of for each actual pixel location identifying at least one desired pixel location corresponding to the actual pixel location includes identifying a first desired pixel location immediately preceding the actual pixel location and identifying a second desired pixel location immediately following the actual pixel location. 
   
   
       4 . The method of  claim 3  wherein the step of determining for each of the identified actual pixel locations that differs from at least two desired pixel locations due to distortion a corresponding set of weighted data as a function of the distortion and image data for the at least two desired pixel locations includes calculating a weighted average of the image data corresponding to the first and second desired pixel locations. 
   
   
       5 . The method of  claim 2  wherein the field of view includes a two dimensional field of view and the step of scanning a beam of light across a field of view through a series of actual pixel locations includes scanning the beam of light along first and second axes. 
   
   
       6 . The method of  claim 5  wherein the first and second axes are substantially orthogonal. 
   
   
       7 . The method of  claim 2  wherein the step of determining for each of the identified actual pixel locations that differs from at least two desired pixel locations due to distortion a corresponding set of weighted data as a function of the distortion and image data for the at least two desired pixel locations includes clocking data out of a memory buffer. 
   
   
       8 . The method of  claim 2  wherein the step of for each actual pixel location identifying at least one desired pixel location corresponding to the actual pixel location includes clocking data out of a memory buffer. 
   
   
       9 . The method of  claim 2  wherein the distortion includes an optical aberration. 
   
   
       10 . The method of  claim 2  wherein the distortion includes scanning distortion. 
   
   
       11 . The method of  claim 2  wherein the scanned beam device includes a scanned beam display and the image data includes data for display. 
   
   
       12 . The method of  claim 11  wherein the scanned beam device includes a video display. 
   
   
       13 . A method for producing a video image comprising the steps of:
 receiving data including pixel data;   loading at least a portion of the received data into a buffer to form display data, wherein a plurality of pixels of display data in the buffer are distorted relative to the corresponding plurality of pixels in the received data;   driving a scanned beam display with the display data to display an image substantially corresponding to the received data, wherein the scanned beam display includes distortion corresponding to the distortion of the pixel data in the buffer.   
   
   
       14 . The method of  claim 13  wherein the scanned beam display distortion includes optical aberration. 
   
   
       15 . The method of  claim 13  wherein the scanned beam display distortion includes scanning distortion. 
   
   
       16 . The method of  claim 13  wherein loading the received data into the buffer includes determining a weighted average of received pixel data to form display data pixels. 
   
   
       17 . The method of  claim 16  wherein the display data pixels are a function of the corresponding received pixel data and the scanned beam display distortion. 
   
   
       18 . The method of  claim 13  wherein the step of loading at least a portion of the received data into a buffer to form display data includes distorting the locations of pixels in the display data relative to the locations of corresponding pixels in the received data. 
   
   
       19 . The method of  claim 18  wherein distorting the locations of pixels in the display data relative to the locations of corresponding pixels in the received data includes moving a plurality of pixels in the received data from one line in the received data to a different line in the display data. 
   
   
       20 . A method of producing a scanned beam image comprising the steps of:
 storing data representing a rectilinear set of pixels in a buffer;   for each line in the image, clocking the stored data out of the buffer at a set of clocking times;   for each of the clocking times determining a location in a scanned beam pattern;   for each of the clocking times, calculating a pixel intensity that is a weighted average of a plurality of the clocked out stored data; and   substantially at each of the clocking times, emitting a beam of light that is modulated according to the corresponding calculated pixel intensity.   
   
   
       21 . The method of  claim 20  wherein the step of calculating a pixel intensity includes calculating a pixel intensity that is a function of a distortion of the location of the emitted beam of light relative to the location of corresponding pixels in the rectilinear set of pixels. 
   
   
       22 . The method of  claim 20  wherein the clocking times are substantially equally spaced. 
   
   
       23 . The method of  claim 20  wherein the clocking times are substantially sinusoidally varying.