US-12619111-B2 - Color filter enhancements for display devices

Abstract

A display system comprising a backlight device having a light emitting array, a liquid crystal panel, and a color filter having one or more absorbing dyes and, optionally, one or more dye enhancement compounds, wherein the one or more absorbing dyes and the one or more dye enhancement compounds are located in at least one color set of subpixels in the color filter. The one or more absorbing dyes may be a soluble, blue light, green light, or red light absorbing dye included in blue, green, or red subpixels of the color filter. A blue light absorbing dye may reduce transmission in a wavelength range of 410-430 nm, a green light absorbing dye may reduce transmission in a wavelength range of 490-570 nm, and a red light absorbing dye may reduce transmission of wavelengths less than 620 nm.

Inventors

• Arkady Garbar
• Derek Harris
• Davis Lee

Assignees

• EYESAFE INC.

Dates

Publication Date

20260505

Application Date

20240313

Claims (20)

1. 1 . A display system comprising: a light emitting array; and a color filter having one or more light absorbing materials, wherein the one or more light absorbing materials are one or more light absorbing dyes, the one or more light absorbing dyes comprise a soluble, primary light absorbing dye, the soluble, primary light absorbing dye has only absorption properties and absorbs light in a particular wavelength range, the color filter is comprised of a plurality of pixels, each pixel is comprised of a red, a green, and a blue subpixel, the subpixels are created from a resin and colorants such that each subpixel has resin and at least one colorant, the colorants are suspended in the resin of the subpixels, the soluble, primary light absorbing dye is dissolved in the resin of at least one color set of the red, green, and blue subpixels, and the soluble, primary light absorbing dye is a separate compound than the colorants.
2. 2 . The display system of claim 1 , further comprising light emitting diodes incorporated into the light emitting array, a reflector adjacent to the light emitting array, a diffuser opposite the reflector, a thin film transistor array layer, and a layer of cover glass.
3. 3 . The display system of claim 1 , wherein the liquid crystal panel is adjacent to the color filter and is comprised of a liquid crystal layer disposed between two panel plates.
4. 4 . The display system of claim 1 , further comprising a first brightness enhancing layer and at least one polarizer, wherein a first polarizer is located adjacent the color filter, a second brightness enhancing layer is adjacent to the first brightness enhancing layer, and a second polarizer is located next to the backlight unit.
5. 5 . The display system of claim 1 , the color filter further comprising one or more dye enhancement compounds located within the resin of at least one color set of the red, green, and blue subpixels in the color filter, wherein the one or more dye enhancement compounds are at least one of a photoinitiator, a polymerization initiation aid, a monomer, and a stabilizer.
6. 6 . The display system of claim 1 , the color filter further comprising one or more dye enhancement compounds located within the resin of at least one color set of the red, green, and blue subpixels in the color filter, wherein the one or more dye enhancement compounds are antioxidants.
7. 7 . The display system of claim 1 , wherein the soluble, primary light absorbing dye is included in blue subpixels of the color filter.
8. 8 . The display system of claim 7 , the one or more absorbing dyes further comprising a soluble, secondary light absorbing dye that only has absorption properties and that absorbs light at wavelengths below 415 nm.
9. 9 . The display system of claim 7 , the one or more absorbing dyes further comprising a soluble, secondary light absorbing dye that only has absorption properties and that absorbs light at wavelengths above 480 nm.
10. 10 . The display system of claim 7 , wherein the soluble, primary light absorbing dye reduces blue light toxicity factor by up to 20%.
11. 11 . The display system of claim 1 , wherein the soluble, primary light absorbing dye is included in green subpixels of the color filter.
12. 12 . The display system of claim 11 , the at least one absorbing dyes further comprising a first, soluble, secondary light absorbing dye that only has absorption properties and that absorbs light at wavelengths below 500 nm or a second, soluble, secondary light absorbing dye that only has absorption properties and that absorbs light at wavelengths above 575 nm.
13. 13 . The display system of claim 1 , wherein the soluble, primary light absorbing dye is included in red subpixels of the color filter.
14. 14 . The display system of claim 13 , the one or more absorbing dyes further comprising a soluble, secondary light absorbing dye that only has absorption properties and that absorbs light at wavelengths below 590 nm.
15. 15 . The display system of claim 1 , the one or more absorbing dyes further comprising a second, soluble, primary light absorbing dye that only has absorption properties, wherein a first, soluble primary light absorbing dye absorbs in the wavelength range 410-430 nm, and a second, soluble primary light absorbing dye absorbs in the wavelength range of 470-495 nm.
16. 16 . The display system of claim 1 , wherein the one or more absorbing dyes are at least one of organic dyes, metal complex dyes, porphyrin-based compounds, coumarins, retinal pigments, and phthalocyanine compounds.
17. 17 . The display system of claim 1 , wherein there is a reduction in luminance of no more than 10% compared to a display system without the one or more absorbing dyes.
18. 18 . The display system of claim 1 , wherein there is a change in color gamut of no more than 5%.
19. 19 . The display system of claim 1 , wherein the absorbing dyes combined with the dye enhancement compounds are heat resistant and resist color gamut coordinate changes more than 0.005 along the X-axis and 0.005 along the Y-axis after being exposed to temperatures of at least 200 degrees Celsius for at least 30 minutes.
20. 20 . The display system of claim 1 , wherein the soluble, primary light absorbing dye is a first soluble, primary light absorbing dye, the one or more light absorbing dyes further comprise a second and a third soluble, primary light absorbing dye, the first soluble, primary light absorbing dye is a blue-light absorbing dye located within the resin of blue subpixels of the color filter, the second soluble, primary light absorbing dye is a green-light absorbing dye located within the resin of green subpixels of the color filter, and the third soluble, primary light absorbing dye is a red-light absorbing dye located within the resin of red subpixels of the color filter.

Description

FIELD The present disclosure relates to backlight modules for electronic display systems that include light management materials. BACKGROUND Blue light has become a health concern with the emergence of light-emitting diodes (LEDs) and their increasing use in electronic display products such as LCD displays. Short-wavelength blue light or high energy natural blue light has been linked to photo retinal damage and thought to be a causal component in the onset of macular degeneration following a long-term exposure to daylight. With daily screen time continuing to increase, especially since the beginning of the COVID-19 pandemic, users are being increasingly exposed to high-energy blue light emitted by their devices. Long-term health implications are now being studied, but eye strain and other immediate effects of display use affect people daily, with an increase in ocular symptoms such as asthenopia and dry eyes, in addition to the recognized impacts of devices' use on circadian rhythms and sleep patterns. Lowering the emission of high energy blue light from devices is thus of great importance, and selective solutions can be implemented within the components of the display panels. Handhelds, tablets, computers, and other device displays have trended toward higher resolutions and truer color balance. While a variety of methods can be used to achieve resolution and color, many high-performance displays include LEDs that can result in high levels of blue within the output spectrum. Many of these devices are battery-powered and users, typically, desire long battery life. Longer battery life generally calls for low power consumption, as well as various means for light conservation. Frequently these displays have not prioritized eye safety as a design goal. A growing body of medical research indicates that a “toxic” blue portion of the color spectrum can have adverse effects on the eye, in such a way that in the longer term, vision troubles and impairment could result. In addition, a new body of knowledge is showing that adverse effects can occur on the natural circadian rhythm of individuals from certain portions of the optical spectrum. The present disclosure describes materials and incorporation of these materials in mobile phones, tablets or monitors built with an LED backlit system, that are highly selective in their ability to reduce exposure to harmful blue and UV light. These materials can be optimized as a function of wavelength and quantity to maintain color white point. Many of these materials reduce total light transmission. However, some of these materials, as described in the present disclosure, can reduce harmful portions of the spectrum to a range of optical wavelengths that are less harmful. In this manner, a balance of reduction of harmful color frequencies, maintenance of optical clarity, and maintenance of true white color balance can be achieved with minimal loss in display brightness. In light of recent medical findings, increasingly ubiquitous displays, and consumer demand for high quality in displays, systems of the present disclosure solve multiple needs in a unique way. Described herein are approaches to blue light emission mitigation that are based upon absorption of light. In some instances, removal of light or conversion of light, without subsequent emission of light in the visible region of the electromagnetic spectrum, can generally result in a decrease in the brightness (measured and/or perceived) of a display, as compared with an otherwise identical reference display without such absorption features. In some cases, to compensate for such an absorption-related brightness decrease, the power input to a display is increased. This may be relative to the power input to a reference display. Generally, increases in display power consumption can be undesirable, particularly in portable devices where they may negatively impact battery life. In this present disclosure, the selective application of color absorption dyes within each color of the display color filters presents great benefits, in terms of reduction of blue light hazard, minimizing negative impacts on luminance change and of the increase in the total color gamut. This is particularly notable when compared to the resulting effects obtained with an implementation at the backlight unit (hereinafter “BLU”) level. SUMMARY To address eye safety, display systems are provided that incorporate materials into mobile, tablet, or personal computer displays that can reduce exposure to harmful or toxic blue and ultraviolet light. The instant disclosure provides backlight modules (units) for display systems that include materials that can convert or recycle harmful portions of the visible electromagnetic spectrum into optical wavelengths that are less harmful while maintaining a balance of reduction in harmful color frequencies, maintenance of optical clarity, and maintenance of true white color balance with minimum loss in display brightness. The