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Teaching or amusement apparatus

  • US 4,604,065 A
  • Filed: 01/23/1985
  • Issued: 08/05/1986
  • Est. Priority Date: 10/25/1982
  • Status: Expired due to Fees
First Claim
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1. Apparatus for use in amusement, manual coordination, teaching, educational evaluation and related purposes, said apparatus comprising a substrate for use in conjunction with a manually manipulatable infra-red emitting and infra-red reflectance measuring device;

  • said substrate comprising;

    a sheet of material having determined transparency and reflectivity to infra-red illumination and having opposed major planar surfaces;

    printed matter in any desired organization applied to at least one of said major planar surfaces of said substrate in printings of infra-red transparent inks in selected screen densities to provide coloring on said surface of desired color, hue and intensity;

    selected portions of said printed matter including at least one printing of infra-red transparent ink and an additional printing in a carbon black infra-red absorptive ink in a sufficiently small screen of dots to minimize visually observed discoloration and graying of said infra-red transparent ink, and to minimize visual detection of the presence of said carbon black ink dots, but, sufficient to cause a detectable drop in infra-red reflectance at said selected portions when said selected portions are illuminated with infra-red light; and

    ,other portions of said printed matter including screens of said printing of blue, red, and yellow infra-red transparent inks in blue, red and yellow ink combinations simulating the visually observed discoloration and graying of said selected portions caused by the presence of said carbon black ink dots in said selected portions, and, to simulate dots of infra-red transparent non-carbon black ink substantially matching said dots of infra-red absorptive carbon black ink in visually observed discoloration and light absorptance characteristics, whereby;

    casual visual inspection of said substrate will fail to reveal differences in the composition of the inks used in the printing of the respective selected portions and said other portions, but, scanning of said printed substrate with said infra-red emitting and reflectance measuring device will enable differentiation by said device between said selected portions and said other portions.

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