US Patent 7046439 - Nanoparticle Enhanced Optical Element

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The shaping and molding of optical elements to control the divergence and focusing of light is one of the oldest technologies known to man. However, the possibilities of innovation in this field have yet to be exhausted. Control of the size and distribution of nanoparticles within nanoparticle/polymer composites provide a mechanism for controlling the refractive index of the composite and thus how the composite disperses or focuses light. This patent provides for nanoparticles formed on the surface rather than throughout such composites to save cost (by using fewer nanoparticles) while producing identical results. Claim 1 reads:

1. An optical element comprising a substrate with thermoplastic surface features on a surface thereof having an Ra of from 3 to 200 micrometers, the surface features containing a dispersion of minute particles having a particle size dimension less than 100 nanometers.

(Ra: average roughness)