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Projection lens system

  • US 5,130,850 A
  • Filed: 12/13/1990
  • Issued: 07/14/1992
  • Est. Priority Date: 12/20/1989
  • Status: Expired due to Term
First Claim
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1. A projection lens system for displaying an image formed on a face panel of a cathode ray tube (CRT) on a screen and including a plurality of lens components disposed at an optical axis and arranged in a series, said projection lens system comprising:

  • (a) a first lens component disposed at an image end of said series of projection lenses having a positive power, and formed of a meniscus shape having a surface convex to the image;

    (b) a second lens component disposed between said first lens component and said face panel, having a positive power in total, and formed of an overall meniscus shape, having at least one aspheric surface and having a surface convex to the image;

    (c) a third lens component disposed between said second lens component and said face panel, and having a negative power;

    (d) a fourth lens component disposed between said third lens component and said face panel, having a positive power, and formed of a bi-convex shape;

    (e) a fifth lens component disposed between said fourth lens component and said face panel, being brought in contact with a surface of said fourth lens component facing said CRT, and having a negative power;

    (f) a sixth lens component disposed between said fifth lens component and said face panel, having a positive power, and formed of a bi-convex shape;

    (g) a seventh lens component disposed between said sixth lens component and said face plate, having a positive power in total, and formed in an overall meniscus-shape having at least one aspheric surface and a surface concave to the image; and

    (h) an eight lens component disposed between said seventh lens component and said face plate, having a negative power, and formed of a plano-concave shape having a surface concave to the image.

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