Red color filter element
View Patent ↗A red color filter having a red filter layer comprising a pigment having a maximum absorption at a wavelength within the range of from 450 to 575 nm, wherein the red filter layer has chromaticity coordinates (x, y) in the 1931 CIE XYZ calorimetric system, calculated using CIE Standard illuminant D65, that satisfy the expressions 0.665≦x≦0.68 and 0.30≦y≦0.34.
1. A red color filter having a red filter layer comprising:
a. a pigment having a maximum absorption at a wavelength within the range of from 450 to 575 nm wherein at least 90 volume percent of the pigment particles have a particle size less than 100 nm; and
b. the red filter layer has a transmittance of 80% or more at a wavelength of 650 nm, no more than 10% at a wavelength of 585 nm, and no more than 5% at all wavelengths in the range from 580 to 410 nm and has chromaticity coordinates (x, y) in the 1931 CIE XYZ colorimetric system, calculated using CIE Standard Illuminant D65, that satisfy the expressions 0.665≦x≦0.68 and 0.30≦y≦0.34,
wherein no more than 10 volume percent of the pigment particles have a particle size less than 5 nm.
2. The red color filter of claim 1 wherein the red filter layer has a transmittance of no more than 2% at all wavelengths in the range from 580 to 410 nm.
3. The red color filter of claim 2 wherein the red filter layer has a transmittance of no more than 1% at all wavelengths in the range from 575 to 410 nm.
4. The red color filter of claim 3 wherein the red filter layer has a transmittance of no more than 2% at 400 nm.
5. The red color filter of claim 1 wherein at least 90 volume percent of the pigment particles have a particle size less than 50 nm.
6. The red color filter of claim 1 wherein the pigment particles are produced by micromedia milling wherein the grinding media comprises beads of a polymeric resin which are substantially spherical in shape and have sizes in the range of 10 to 100 microns.
7. A display device comprising the red color filter of claim 1 .
8. The display device of claim 7 wherein the display device is an electronic display.
9. The display device of claim 8 wherein the electronic display is an OLED display.
10. The red color filter of claim 1 wherein the red filter layer comprises at least 10% pigment by weight.
11. The red color filter of claim 10 wherein the red filter layer comprises at least 25% pigment by weight.
12. A red color filter having a red filter layer comprising:
a. a pigment having a maximum absorption at a wavelength within the range of from 450 to 575 nm wherein at least 90 volume percent of the pigment particles have a particle size less than 100 nm; and
b. the red filter layer has a transmittance of 80% or more at a wavelength of 650 nm, no more than 10% at a wavelength of 585 nm, and no more than 5% at all wavelengths in the range from 580 to 410 nm and has chromaticity coordinates (x, y) in the 1931 CIE XYZ colorimetric system, calculated using CIE Standard Illuminant D65, that satisfy the expressions 0.665≦x≦0.68 and 0.30≦y≦0.34,
wherein the pigment consists essentially of a single red pigment.
13. The red color filter of claim 12 wherein the red pigment is a diketopyrrolopyrrole pigment.
14. The red color filter of claim 13 wherein the red pigment is Pigment Red 254.
15. The red color filter of claim 12 , wherein no more than 10 volume percent of the pigment particles have a particle size less than 5 nm and wherein at least 90 volume percent of the pigment particles have a particle size less than 50 nm.
16. A display device comprising the red color filter of claim 12 , wherein the display device is an OLED display.