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 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, and
wherein the first absorbing compound absorbs in a wavelength range from about 260 nm to about 400 nm, and the second absorbing compound absorbs in a wavelength range of from about 800 nm to about 1200 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 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 absorbs in a wavelength range from about 400 nm to about 700 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 polysolfone, a polyurethane, 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 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 point.
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 compound comprises a pressure-sensitive adhesive.
16. A method of making a light-filtering film comprising:
providing a screen for an electronic device;
impregnating at least one of a first absorbing compound combined with a 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, or 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 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, and
wherein the first absorbing compound absorbs in a wavelength range of from about 260 nm to about 400 nm, and the second absorbing compound absorbs in a wavelength range of from about 800 nm to about 1200 nm.
17. A method of making a light-filtering film according to claim 16 , further comprising a third absorbing compound absorbing light between the blue notch and the red notch.
18. A method of making a light-filtering film according to claim 17 , wherein the third absorbing compound absorbs in a wavelength range of from about 400 nm to about 700 nm.
19. A method according to claim 18 , wherein the method further comprises:
coating an adhesive on the polymer substrate before applying the light-filtering film to the screen.
20. A method of making a light-filtering film comprising:
providing a screen of an electronic display device;
providing a polymer substrate, wherein the polymer substrate comprises:
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 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; and
applying the light-filtering film to the screen,
wherein the first absorbing compound absorbs in a wavelength range of from about 260 nm to about 400 nm, and the second absorbing compound absorbs in a wavelength range of from about 800 nm to about 1200 nm.
21. A method of making a light-filtering film according to claim 20 , further comprising a third absorbing compound absorbing light between the blue notch and the red notch, wherein the third absorbing compound absorbs in a wavelength range of from about 400 nm to about 700 nm.
22. 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 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, and
wherein the first absorbing compound absorbs in a wavelength range from about 420 nm to about 445 nm, and the second absorbing compound absorbs in a wavelength range of from about 630 nm to about 685 nm.
23. A light-filtering film according to claim 22 , further comprising a third absorbing compound combined with the polymer substrate, the third absorbing compound absorbing light in a band between the blue notch band and the red notch band.
24. A light-filtering film according to claim 23 , wherein the third absorbing compound absorbs in a wavelength range from about 565 nm to about 600 nm.