Light emission reducing compounds for electronic devices
Double-notch filters for electronic devices are provided that filter light from both the blue spectrum as well as the red spectrum in narrow wavelength bands, or “notches.” A double-notch filter can, using input light from a conventional LED-backlit LCD display, output light that can be measured as substantially satisfying criteria for a D65 white point. In some examples, a double-notch filter can output light that can be measured as nearly satisfying criteria for a D65 white point, to within +/− 500 Kelvin. In some examples, a double-notch filter can output light that can be measured as nearly satisfying criteria for a D65 white point, to within +/− 1000 Kelvin.
1. A light-filtering film for a screen of a device comprising:
a polymer substrate;
a first absorbing compound combined with the polymer substrate, the first absorbing compound absorbing blue light in a blue notch band having a full-width half-maximum of not greater than about 50 nm; and
a second absorbing compound combined with the polymer substrate, the second absorbing compound absorbing red light in a red notch band having a full-width half-maximum of not greater than about 50 nm,
wherein the first absorbing compound comprises an absorption that has a maximum absorbance peak from about 420 nm to about 445 nm, and the second absorbing compound comprises an absorption that has a maximum absorbance peak from about 640 nm to about 700 nm.
2. A light-filtering film according to claim 1 , further comprising a third absorbing compound combined with the polymer substrate, the third absorbing compound absorbing light absorbing light in a band between the blue notch band and the red notch band.
3. A light-filtering film according to claim 2 , wherein the third absorbing compound comprises an absorption that has a maximum absorbance peak from about 565 nm to about 600 nm.
4. A light-filtering film according to claim 1 , wherein the polymer substrate comprises an acrylic polymer, an epoxy polymer, a polyamide, a polycarbonate, a polyester, a co-polyester of PETG and PCTG, a polyethylene, a polyolefin, a polypropylene, a polystyrene, a polysulfone, a polyurea, a polyvinyl chloride, or a styrene acrylonitrile.
5. A light-filtering film according to claim 1 comprising at least one of an antiglare coating, a hard coating, and a tack coating.
6. A light-filtering film according to claim 1 , wherein the film is applied to an electronic device.
7. A light-filtering film according to claim 6 , wherein the electronic device comprises at least one of an LED (light-emitting diode), LCD (liquid-crystal display), computer monitor, equipment screen, television, tablet, or cellular phone.
8. A light-filtering film according to claim 6 , wherein the electronic device comprises a capacitive touch screen.
9. A light-filtering film according to claim 1 , wherein the first absorbing compound comprises a blue or blue-green organic dye dispersed therein.
10. A light-filtering film according to claim 9 , wherein the organic dye comprises a blue-green phthalocyanine dye.
11. A light-filtering film according to claim 9 , wherein the organic dye comprises between about 0.05 percent to about 2.00 percent of the polymer substrate by weight.
12. A light-filtering film according to claim 1 , wherein the filter can output light that measures to within 1000 Kelvin of a D65 white light.
13. A light-filtering film according to claim 1 , wherein the first absorbing compound, the second absorbing compound, or both are impregnated into the polymer substrate.
14. A light-filtering film according to claim 1 comprising an adhesive.
15. A light-filtering film according to claim 14 , wherein the adhesive comprises a pressure-sensitive adhesive.
16. A light-filtering film according to claim 1 , wherein the first absorbing compound and the second absorbing compound are provided in combination so that, for light produced by the screen transmitted through the light-filtering film, correlated color temperature is within about 1000 Kelvin of correlated color temperature for light produced by the screen that is not transmitted through the light-filtering film.