Patent ID: 6429446
Filing Date: 2002-08-06
Classification: F41G,G01S,G02B,H04K

Abstract:
Apparatus for modulating a source of radiant energy to provide at least three distinct signals of substantially different spectral bands &Dgr;&lgr;i, &Dgr;&lgr;j and &Dgr;&lgr;k, comprising:a first reticle having first and second segments of different spectral transmission characteristics, said first segments of said first reticle providing transmission of source radiant energy at all of said different spectral bands and said second segments of said first reticle rejecting transmission at a first predetermined band &Dgr;&lgr;i and transparent at all other of said different spectral bands, a second reticle in series with said first reticle having at least first and second segments of different spectral transmission characteristics, said first segments of said second reticle providing transmission of source radiant energy at all of said different spectral bands and said second segments of said second reticle rejecting transmission at a second predetermined band &Dgr;&lgr;j and transparent at all other of said different spectral bands, and a third reticle in series with said first and second reticles having at least first and second segments of different spectral transmission characteristics, said first segments of said third reticle providing transmission of source radiant energy at all of said different spectral bands and said second segments of said third reticle rejecting transmission at a third predetermined band &Dgr;&lgr;k and transparent at all other of said different spectral bands.