US Patent 7537346 - Fluorescent nanoparticle display

http://www.freepatentsonline.com/7537346.html

Quantum dot nanocrystal phosphors have been suggested to improve display efficiency as far back as 1994 (see US Patent 5,882,779). This patent from Superimaging, Inc. teaches using a dark substrate (such as a vehicle dashboard) in forming the display to improve contrast. Claim 1 reads:

1. An apparatus comprising light emitting material integrated into a substantially dark substrate, wherein:

the light emitting material is configured to emit visible light in response to absorption of ultraviolet light, wherein the light emitting material is fluorescent material;

the light emitting material comprises a plurality of light emitting particles; and each of the plurality of light emitting particles has a diameter less than about 500 nanometers.