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Optical illumination and distortion compensator

  • US 4,234,891 A
  • Filed: 07/30/1979
  • Issued: 11/18/1980
  • Est. Priority Date: 07/30/1979
  • Status: Expired due to Term
First Claim
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1. A method of compensating for the distortion developed in an optical display apparatus due to the imposition of a concave spherical mirror for viewing intermediate a viewing position and a curved rear-projection screen and for improving the illumination substantially simultaneously, comprising:

  • establishing a viewing position,arranging a concave spherical mirror for viewing from said viewing position by at least one trainee,positioning a curved rear-projection screen on the side of said concave spherical mirror so that the image on said screen is visible when reflected by said mirror toward said viewing position,locating a curved folding mirror adjacent said curved rear-projection screen so that an image is reflected from the curved folding mirror onto said screen,positioning the major axes of said curved folding mirror and said curved rear-projection screen in a predetermined relationship relative to each other, whereby distortion is reduced and illumination increased substantially simultaneously; and

    projecting an image for reflection from said curved folding mirror onto said curved rear-projection screen so that said image is viewed at said viewing position substantially undistorted and with substantially maximum illumination.

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