SBIR-STTR Award

The color filters currently used to convert black-and-white LCD displays to color displays severely limit the brightness of the displays because available color filter materials (dyes and glasses) are inherently rather broadband. Consequently, if they are dense enough to limit the transmitted light to a reasonably narrow band for color purity, they also cut down on the brightness of the transmitted light. What is needed is a family of dyes with steep cutoffs at the edges of their passbands; in other words, unusually narrow passbands. Few, if any, dyes of commerce offer narrow passbands; but the porphyrin and phthalocyanine dyes offer unusually narrow absorption bands, and the absorptions of a series of narrowband absorbers can be "stacked" to five a filter with a bright, steep-sided passband anywhere in the spectrum. Some porphyrin and phthalocyanine dyes are available, but not enough of them to fill the spectrum. This proposal offers to develop syntheses for additional dyes with narrow absorption bands spaced throughout the visible spectrum and to demonstrate the enhanced display brightness that they can provide.Anticipated

Benefits:
These new dyes will enable the manufacture of color filters with high light transmission and high color purity for use in both military and civilian lcd displays. The technology can also be used in the manufacture of improved photographic color films and in the manufacture of greatly improved inexpensive sunglasses.

The color filters currently used to convert black-and-white LCD displays to color displays severely limit the brightness of the displays because available color filter materials are inherently rather broadband. Consequently, if they are dense enough to limit the transmitted light to a reasonably narrow band for color purity, they also cut down on the brightness of the transmitted light. What is needed is a family of dyes with steep cutoffs at the edges of their passbands; in other words, unusually narrow clear passbands. Few, if any, dyes of commerce offer narrow passbands; but the phthanlocyanine family of dyes does offer unusually narrow bands, and a series of them could be "stacked" to give a composite filter with a bright, steep-sided passband anywhere in the spectrum. Phase I of this project demonstrated the synthesis of several phthalocyanine dyes with steep-sided bands in the red region of the spectrum. Phase II will extend this work and synthesize a series of dyes with steep-sided bands throughout the spectrum and demonstrate the incorporation of those dyes into improved LCD color displays. Anticipated

Benefits:
These new dyes will enable the manufacture of color displays with high light transmission and high color purity for use in both military and civilian LCD displays. They will also enable the manufacture of much improved and much less expensive laser-protective eyewear and improved color filters in general.