Apparatus and Method for Interpolating the Intensities of Scanned Pixels from Source Pixels

Abstract

A scan assembly of an image generator sweeps an image beam in a first dimension at a first rate and bi-directionally in a second dimension at a slower rate. Sweeping the beam bi-directionally in the vertical dimension (generally the dimension of the lower sweep rate) can reduce the scanning power by eliminating the flyback period, and, where the scan assembly includes a mechanical reflector, can reduce the error in the beam position without a feedback loop by reducing the number of harmonics in the vertical sweep function. Furthermore, because the image beam is “on” longer due to the elimination of the flyback period, the scanned image is often brighter for a given beam intensity. The scan assembly may also sweep the image beam non-linearly in the vertical dimension, and this sweep may be bi-directional or uni-directional. Sweeping the beam non-linearly can also reduce the error in the beam position by reducing the number of harmonics in the vertical sweep function.

1 - 71 . (canceled) 
   
   
       72 . An image generator, comprising:
 a scan assembly operable to scan an image by sweeping an image beam in a first dimension and non-linearly in a second dimension, the image beam having an intensity and operable to generate scanned pixels of the scanned image;   a clock generator operable to generate a pixel clock; and   a beam generator coupled to the clock generator and, in response to each cycle of the pixel clock, operable to interpolate a respective scanned pixel of the scanned image by interpolating the intensity of the image beam from a respective original pixel of an original image upon which the scanned image is based.   
   
   
       73 . The image generator of  claim 72  wherein:
 the first dimension comprises a vertical dimension; and   the second dimension comprises a horizontal dimension.   
   
   
       74 . The image generator of  claim 72  wherein:
 the first dimension comprises a horizontal dimension; and   the second dimension comprises a vertical dimension.   
   
   
       75 . The image generator of  claim 72  wherein the scan assembly is operable to sweep the image beam sinusoidally in the second dimension. 
   
   
       76 . The image generator of  claim 72  wherein the scan assembly is operable to sweep the image beam in the second dimension according to a sinusoid of a fundamental frequency and a sinusoid of a harmonic of the fundamental frequency. 
   
   
       77 . The image generator of  claim 72  wherein the clock generator is operable to generate the pixel clock such that the scanned pixels are substantially evenly spaced in the second dimension. 
   
   
       78 . The image generator of  claim 72  wherein the clock generator is operable to generate the pixel clock such that the scanned pixels are unevenly spaced in the second dimension. 
   
   
       79 . The image generator of  claim 72  wherein:
 the first and second dimensions respectively comprise vertical and horizontal dimensions;   the clock generator is operable to generate the pixel clock such that the scanned pixels are substantially aligned with the respective original pixels in the vertical dimension; and   the beam generator is operable to interpolate the respective scanned pixel by interpolating the intensity of the image beam from a respective original pixel that is substantially aligned with the scanned pixel in the vertical dimension.   
   
   
       80 . The image generator of  claim 72  wherein:
 the first and second dimensions respectively comprise vertical and horizontal dimensions;   the scan assembly is operable to sweep the image beam non-linearly in the vertical dimension;   the clock generator is operable to generate the pixel clock such that the scanned pixels are substantially aligned with the respective original pixels in the vertical dimension; and   the beam generator is operable to interpolate each scanned pixel by interpolating the intensity of the image beam from a respective original pixel that is substantially aligned with the scanned pixel in the vertical dimension.   
   
   
       81 . The image generator of  claim 72  wherein:
 the first and second dimensions respectively comprise vertical and horizontal dimensions;   the clock generator is operable to generate the pixel clock such that the scanned pixels are substantially aligned with the respective original pixels in the vertical dimension and that some of the scanned pixels are misaligned with the respective original pixels in the horizontal dimension; and   the beam generator is operable to interpolate each of misaligned scanned pixel by interpolating the intensity of the image beam from two respective original pixels that are substantially aligned with and that are on opposite sides of the misaligned scanned pixel in the vertical dimension.   
   
   
       82 . The image generator of  claim 72  wherein:
 the first and second dimensions respectively comprise vertical and horizontal dimensions;   the clock generator is operable to generate the pixel clock such that some of the scanned pixels are misaligned with the respective original pixels in the vertical and horizontal dimensions; and   the beam generator is operable to interpolate each misaligned scanned pixel by interpolating the intensity of the image beam from three respective original pixels that together define a region in which the misaligned scanned pixel is located.   
   
   
       83 . The image generator of  claim 72  wherein:
 the first and second dimensions respectively comprise vertical and horizontal dimensions;   the scan assembly is operable to sweep the image beam non-linearly in the vertical dimension;   the clock generator is operable to generate the pixel clock such that some of the scanned pixels are misaligned with the respective original pixels in the vertical and horizontal dimensions; and   the beam generator is operable to interpolate each misaligned scanned pixel by interpolating the intensity of the image beam from four respective original pixels that together define a region in which the misaligned scanned pixel is located.   
   
   
       84 . A method, comprising:
 generating pixels of a scanned image by sweeping an image beam in a first dimension and non-linearly in a second dimension; and   interpolating an intensity of the image beam for each scanned pixel from a respective original pixel of an original image upon which the scanned image is based.   
   
   
       85 . The method of  claim 84  wherein generating the pixels of the scanned image comprises sweeping the image beam sinusoidally in the second dimension. 
   
   
       86 . The method of  claim 84  wherein generating the pixels of the scanned image comprises sweeping the image beam in the second dimension according to a sinusoid of a fundamental frequency and a sinusoid of a harmonic of the fundamental frequency. 
   
   
       87 . The method of  claim 84  wherein interpolating the intensity of the image beam comprises interpolating the intensity at respective times that cause the scanned pixels to be substantially evenly spaced in the second dimension. 
   
   
       88 . The method of  claim 84  wherein interpolating the intensity of the image beam comprises interpolating the intensity at respective times that cause the scanned pixels to be unevenly spaced in the second dimension. 
   
   
       89 . The method of  claim 84  wherein interpolating the intensity of the image beam comprises:
 interpolating the intensity at respective times that cause the scanned pixels to be substantially aligned with the original pixels in the first dimension; and   interpolating the intensity for each scanned pixel from a respective original pixel that is substantially aligned with the scanned pixel in the first dimension.   
   
   
       90 . The method of  claim 84  wherein:
 generating the pixels of the scanned image comprises sweeping the image beam non-linearly in the first dimension; and   interpolating the intensity of the image beam comprises,
 interpolating the intensity at respective times that cause the scanned pixels to be substantially aligned with the original pixels in the first dimension; and 
 interpolating the intensity for each scanned pixel from a respective original pixel that is substantially aligned with the scanned pixel in the first dimension. 
   
   
   
       91 . The method of  claim 84  wherein interpolating the intensity of the image beam comprises:
 interpolating the intensity at respective times that cause the scanned pixels to be substantially aligned with the original pixels in the first dimension and that cause at least some of the scanned pixels to be misaligned with the respective original pixels in the horizontal direction; and   interpolating the intensity for each misaligned scanned pixel from two respective original pixels that are substantially aligned with and that are on opposite sides of the misaligned scanned pixel in the vertical dimension.   
   
   
       92 . The method of  claim 84  wherein interpolating the intensity of the image beam comprises:
 interpolating the intensity at respective times that cause at least some of the scanned pixels to be misaligned with the respective original pixels in the first and second dimensions; and   interpolating the intensity for each misaligned scanned pixel from three respective original pixels that together define a region in which the misaligned scanned pixel is located.   
   
   
       93 . The method of  claim 84  wherein:
 generating the pixels of the scanned image comprises sweeping the image beam non-linearly in the first dimension; and   interpolating the intensity of the image beam comprises,
 interpolating the intensity at respective times that cause at least some of the scanned pixels to be misaligned with the respective original pixels in the first and second dimensions, and 
 interpolating the intensity for each misaligned scanned pixel from four respective original pixels that together define a region in which the misaligned scanned pixel is located.