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Indicator device and illumination device

  • US 6,517,213 B1
  • Filed: 11/25/1998
  • Issued: 02/11/2003
  • Est. Priority Date: 03/31/1997
  • Status: Expired due to Term
First Claim
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1. An indicator device which makes an indication by illuminating a predetermined indicating surface, comprising:

  • a light source for emitting a light of a first wavelength (L1); and

    a fluorescent plate provided between said light source and said indicating surface, for changing at least part of said light of said first wavelength projected thereto from said light source into a light of a second wavelength (L2) longer than said first wavelength and projecting said light of said second wavelength towards said indicating surface, wherein said light source comprises a plurality of semiconductor light-emitting elements for emitting a light of any wavelength ranging from ultraviolet to blue as said light of said first wavelength (L1), wherein said plurality of semiconductor light-emitting elements are arranged in a matrix with a plurality of rows and columns to face the back surface of said fluorescent plate and uniformly project said light of first said wavelength towards said fluorescent plate.

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