Claims
- 1. A digital imager comprising:a pair of liquid crystal filters tunable to different wavelengths of light in the visible spectrum; and a dye incorporated into said liquid crystal filter, said dye having an absorbance of less than about 50 cm.2/mg. from about 500 to about 700 nm. and an absorbance of greater than 50 cm.2/mg. from about 800 to about 1200 nm.
- 2. The imager of claim 1 wherein said imager also includes an imaging array and an image processor.
- 3. The imager of claim 1 wherein said dye is coated on one of said filters.
- 4. The imager of claim 1 wherein said dye is incorporated in a liquid crystal contained in one of said filters.
- 5. The imager of claim 1 wherein said dye includes anthraquinone.
- 6. The imager of claim 1 wherein said dye includes a mixture of two dyes which block infrared over a wider wavelength range than either of said dyes individually.
- 7. The imager of claim 1 wherein said dye includes a bis (dithiobenzil) nickel complex.
- 8. The imager of claim 7 wherein said dyes include a mixture of bis((4-dimethylamino) dithiobenzil) nickel complex and bis(dithiobenzil) nickel complex.
Parent Case Info
This is a divisional of prior application Ser. No. 09/164,202 filed Sep. 30, 1998 now U.S. Pat. No. 6,208,393.
US Referenced Citations (7)