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Holographic diffusion screen and methods for the production thereof

  • US 4,602,843 A
  • Filed: 12/03/1982
  • Issued: 07/29/1986
  • Est. Priority Date: 07/26/1976
  • Status: Expired due to Fees
First Claim
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1. A diffusing screen usable in bringing an image passing through an image-forming optical element or system to focus thereon, comprising an optically-generated or computer-generated holographic element which, upon reconstruction, displays an image comprising a relatively transmittant pattern on a substantially opaque background, wherein the outer periphery of said relatively transmittant pattern substantially defines a circle, said circle having a diameter approximating the diameter of the exit pupil of the optical element or system through which the image to be focused passes when in use, and wherein a substantial area of said image surrounding the center of said circle is part of said substantially opaque background, whereby a substantially annular relatively transmittant pattern is formed around the center of said circle to thereby provide a focusing screen with increased blur of out-of-focus images without substantial loss of brightness.

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