Improving the performance of color filters for display devices

Abstract

To provide a display system that reduces the hazards of blue light, minimizes the adverse effects of luminance changes, and expands the total color gamut. The display system includes a backlight having an array of light emitters, a liquid crystal panel, and a color filter having one or more absorbing dyes and, optionally, one or more dye enhancement compounds disposed in at least one color set of subpixels in the color filter. The one or more absorbing dyes may be soluble blue, green, or red light absorbing dyes in blue, green, or red subpixels of the color filter. The blue light absorbing dyes can reduce the transmittance in the wavelength range of 410-430 nm, the green light absorbing dyes can reduce the transmittance in the wavelength range of 490-570 nm, and the red light absorbing dyes can reduce the transmittance of wavelengths less than 620 nm.

Description

[Technical field]

[0001] The present disclosure relates to backlight modules for electronic display systems that include light management materials. [Background technology]

[0002] With the advent of light-emitting diodes (LEDs) and their increasing use in electronic display products such as LCD displays, blue light has become a health concern. Short wavelength blue light or high energy natural blue light has been associated with retinal photodamage and is believed to be a causative factor in the development of macular degeneration after prolonged exposure to sunlight. As daily screen time continues to increase, especially since the start of the COVID-19 pandemic, users are increasingly exposed to high energy blue light emitted by devices. While long term health effects are currently under study, eye fatigue and other immediate effects of display use affect people on a daily basis, with an increase in ocular symptoms such as eye strain and dry eyes, in addition to the recognized impact of device use on circadian rhythms and sleep patterns. Therefore, it is crucial to limit the emission of high energy blue light from devices, and selective solutions can be implemented within the components of the display panel.

[0003] Displays for handhelds, tablets, computers, and other devices are becoming higher resolution and more faithful color balance. While various methods can be used to achieve resolution and color, many high performance displays include LEDs that can provide high levels of blue in the output spectrum. Many of these devices are battery powered, and users typically desire long battery life. Long battery life typically requires low power consumption and various light saving measures. These displays often do not prioritize eye safety as a design goal. A growing body of medical research shows that the "toxic" blue portion of the color spectrum can have adverse effects on the eye, causing vision impairment and loss in the long term. Additionally, a new body of knowledge shows that certain parts of the light spectrum can have adverse effects on an individual's natural circadian rhythm. This disclosure describes materials with the ability to very selectively reduce exposure to harmful blue and ultraviolet light, and the incorporation of these materials into a mobile phone, tablet, or monitor built with an LED backlight system. These materials can be optimized as a function of wavelength and amount to maintain the white point of the color. Many of these materials reduce the total light transmission. However, as described in this disclosure, some of these materials can reduce the harmful portions of the spectrum to a less harmful range of light wavelengths. In this way, a balance of reduced harmful color frequencies, maintaining optical transparency, and maintaining true white balance can be achieved while minimizing loss of brightness in the display. Given recent medical findings, the increasing prevalence of displays, and consumer demand for high quality displays, the system of the present disclosure solves multiple needs in a unique way. Summary of the Invention

[0004] This disclosure describes methods of mitigating blue light emissions based on the absorption of light. In some cases, removing or converting light in the visible region of the electromagnetic spectrum without subsequent light emission may reduce the brightness (measured and / or perceived) of the display compared to an otherwise identical reference display lacking such absorption characteristics. In some cases, to compensate for the reduction in brightness associated with such absorption, the power input to the display is increased, which may be relative to the power input to the reference display. In general, increasing the power consumption of the display may be undesirable and may adversely affect battery life, especially in portable devices.

[0005] In the present disclosure, the selective application of color absorbing dyes within each color of a display color filter provides significant advantages in reducing blue light hazards, minimizing adverse effects on luminance change, and increasing total color gamut, especially when compared to the resulting benefits achieved with implementation at the backlight unit (hereinafter "BLU") level.

[0006] To address eye safety, a display system is provided that incorporates materials into a mobile, tablet, or personal computer display that can reduce exposure to harmful or toxic blue and ultraviolet light. The present disclosure provides a backlight module (unit) for the display system that includes materials that can convert or recycle harmful portions of the visible electromagnetic spectrum into less harmful wavelengths of light while maintaining a balance between reducing harmful color frequencies, maintaining optical transparency, and maintaining true white balance with minimal loss of display brightness.

[0007] The present disclosure provides for modification of the resulting spectral emissions of LCD displays or systems with LED backlight systems, including the use of dyes or combinations of dyes at the color filter level of these display systems that can absorb harmful portions of the visible electromagnetic spectrum while maintaining a balance between reducing harmful color frequencies, maintaining optical transparency, and maintaining true white balance with minimal loss of display brightness.

[0008] The present disclosure improves color transmission and can also improve color. Improvements in the color filter layer of the display system improve transmission, brightness, and color gamut. In one embodiment, there are high transmission or low color gamut filters. In another embodiment, the color filters improve transmission. The color filter layer may contain specific dyes, pigments, or compounds that affect specific wavelengths and reduce blue light toxicity. The dyes narrow the color value range of the emission to reduce overlap / leakage between subpixels, improving the color gamut of the resulting emission.

[0009] In one embodiment, a display system is disclosed that includes a backlight unit having a light-emitting array, a liquid crystal panel, and a color filter having one or more absorbing dyes disposed within at least one color set of subpixels in the color filter. The system may further include a light-emitting diode incorporated in 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 cover glass layer. The liquid crystal panel may be comprised of a liquid crystal layer adjacent to the color filter and disposed between two panel plates.

[0010] In some embodiments, the system further includes a first brightness enhancing layer and at least one polarizer, the first polarizer being disposed adjacent to the color filter. Additionally, a second brightness enhancing layer may be disposed adjacent to the first brightness enhancing layer. Additionally, the second polarizer may be disposed next to the backlight unit.

[0011] In some cases, the one or more absorbing dyes are soluble blue light absorbing dyes in the blue subpixels of the color filter, where the blue light absorbing dyes can absorb blue light and reduce the transmittance in the wavelength range of 415-435 nm. The system can further include a short wavelength absorber that absorbs light with wavelengths less than 415 nm. Alternatively, or in addition, the system can further include a long wavelength absorber that absorbs light with wavelengths greater than 480 nm. In some cases, the blue light absorbing dye can reduce the toxicity factor of blue light by up to 20%.

[0012] In some cases, the one or more absorbing dyes are soluble green light absorbing dyes in the green subpixels of the color filter, where the green light absorbing dyes can absorb green light and reduce transmittance in the wavelength range of 490 to 570 nm. Further, the one or more absorbing dyes can include a short wavelength absorber that absorbs light with wavelengths less than 500 nm, a long wavelength absorber that absorbs light with wavelengths greater than 575 nm, or both.

[0013] In some cases, the one or more absorbing dyes are soluble red light absorbing dyes in the red subpixels of the color filter, where the red light absorbing dye absorbs red light and can reduce the transmittance of wavelengths less than 620 nm. Additionally, the one or more absorbing dyes include a short wavelength absorber that absorbs light at wavelengths less than 590 nm.

[0014] In some cases, the one or more absorbing dyes can be at least one of a soluble blue dye absorbing in the wavelength range of 415-435 nm, a soluble green dye absorbing in the wavelength range of 520-550 nm, and any combination thereof. The one or more absorbing dyes can be at least one of an organic dye, a metal complex dye, a porphyrin-based compound, a coumarin, a retinal pigment, and a phthalocyanine compound.

[0015] In some cases, the luminance may be reduced by 10% or less compared to a display system lacking one or more absorbing dyes, and / or the color gamut may change by 5% or less.

[0016] In some cases, the one or more absorbing dyes may be disposed in at least one of the blue subpixels, the red subpixels, the green subpixels, and any combination thereof.

[0017] In another aspect, a method of using color filters in a display system is disclosed, in which a backlight unit having a light-emitting array is illuminated, light is emitted through a liquid crystal panel, and the light is absorbed by a color filter having one or more absorbing dyes, the one or more absorbing dyes being disposed in at least one color set of subpixels in the color filter.

[0018] In this disclosure, The term "light absorbing material" or "light absorbing layer" refers to an optical management material that absorbs only light in a specific wavelength range. The term "light absorbing material" or "light absorbing layer" refers to an optical management material that absorbs light in a particular wavelength range and re-emits light in a different (eg, higher) wavelength range. The term "optical film" refers to a light-absorbing or light-converting material disposed adjacent to or on a transparent carrier layer. The term "adjacent" refers to layers that are either immediately adjacent to one another or separated by at most one additional layer. The terms "blue light" or "toxic blue light" refer to light having a wavelength range of about 400 nm to about 500 nm or about 415 nm to about 455 nm, respectively. The term "disposed" refers to a layer that is in direct contact with or adjacent to another layer. The term "light emitting diode array" refers to one or more light emitting diodes in a matrix, usually two dimensional. The term "color filter" refers to an array of blue, red, and green subpixels arranged in a single layer in the optical stack. The term "optical stack" refers to layers in a backlight unit that emit light, are optically transparent to that light, or modify the properties of that light. These layers may be adjacent to one another. "Blue light ratio" refers to a ratio of display emission light in the range of 415-455 nm to display emission light in the range of 400-500 nm that is less than 50%. Formula 1

[0019] JPEG0003250559000002.jpg18160 Here, L(λ) is μWcm -2 nm -1 is the spectral irradiance in units of blue light. The term "Blue Light Toxicity Factor" (BLTF) refers to the weighted harmful blue light ratio B(λ) compared to the display luminance calculated according to the toxicity weighting factor B(λ). Equation 2

[0020] JPEG0003250559000003.jpg18160 where: Δλ = 1 L(λ): Spectral radiance (μW cm -2 nm -1 ) B(λ): Blue light hazard function g(λ): CIE 1931 RGB lightness function 683 - Maximum Spectral Luminous Efficiency Constant (683 lumens per watt at 555 nm). The term "color gamut" refers to the full range of colors available on a particular device. The term "luminance" refers to the intensity of light emitted from a surface per unit area in a particular direction.

[0021] The features and advantages of the present disclosure will be more readily understood from the following detailed description, which should be read in conjunction with the accompanying drawings. [Brief description of the drawings]

[0022] The drawings are schematic and are not intended to limit the scope of the disclosure in any way. Also, the drawings are not necessarily to scale.

[0023] [Figure 1] FIG. 2 is a non-limiting diagram showing an exploded view of the different layers of a display panel.

[0024] [Diagram 2] FIG. 2 is a non-limiting example of a transmittance spectrum of a blue dye modified color filter.

[0025] [Diagram 3] FIG. 2 is a non-limiting diagram of the spectral power distribution of a display with simulated blue dye absorption on a color filter.

[0026] [Figure 4] FIG. 2 is a non-limiting diagram of the spectral power distribution of a display with simulated blue dye absorption at the backlight unit level.

[0027] [Diagram 5] FIG. 2 is a non-limiting example of a transmittance spectrum of a green dye modified color filter.

[0028] [Figure 6] FIG. 2 is a non-limiting diagram of the spectral power distribution of a display with simulated green dye absorption on a color filter.

[0029] [Figure 7] FIG. 2 is a non-limiting diagram of the spectral power distribution of a display with simulated green dye absorption at the backlight unit level.

[0030] [Figure 8] FIG. 2 is a non-limiting example of a transmittance spectrum of a red dye modified color filter.

[0031] [Figure 9] FIG. 2 is a non-limiting diagram of the spectral power distribution of a display simulating the absorption of a red dye on a color filter.

[0032] [Figure 10] FIG. 2 is a non-limiting diagram of the spectral power distribution of a display with simulated red dye absorption at the backlight unit level.

[0033] [Figure 11] FIG. 2 is a non-limiting diagram of possible transmittance spectra for a color filter with both blue and green dye modifications.

[0034] [Figure 12] FIG. 2 is a non-limiting diagram of the spectral power distribution of a display simulating the absorption of blue and green dyes on a color filter.

[0035] [Figure 13] FIG. 2 is a non-limiting diagram of the spectral power distribution of a display with simulated blue and green dye absorption at the backlight unit level.

[0036] [Figure 14a] FIG. 2 is a non-limiting diagram of a display of simulated spectral power distribution of red, blue and green dye absorption at the backlight unit level with original unmodified color filters.

[0037] [Figure 14b] FIG. 13 is a non-limiting diagram of a display of spectral power distribution with simulation of red, blue, and green dye absorption at the backlight unit level with dye modification.

[0038] [Figure 15a]1 is a non-limiting diagram of a display of simulated spectral power distribution of blue dye absorption at the backlight unit level by dye type. [Figure 15b] FIG. 13 is a non-limiting display diagram of simulated spectral power distribution of red dye absorption at the backlight unit level for each dye type. [Figure 15c] FIG. 13 is a non-limiting diagram of a display of simulated spectral power distribution of green dye absorption at the backlight unit level, by dye type.

[0039] [Figure 16a] 1 is a non-limiting diagram of a display of simulated spectral power distributions of red, blue, and green color filter modifications with original unmodified RGB.

[0040] [Figure 16b] 1 is a non-limiting diagram of a simulated spectral power distribution display of modified RGB red, blue, and green color filters. FIG.

[0041] [Figure 17a] 13A-13C are non-limiting diagrams of simulated spectral power distribution displays of blue dye in color filter modifications for each of the identified color targeting dyes. [Figure 17b] 13A-13C are non-limiting diagrams of simulated spectral power distribution displays of red dye in color filter modifications for each of the identified color targeting dyes. [Figure 17c] 13A-13C are non-limiting diagrams of simulated spectral power distribution displays of green dye in color filter modifications for each of the identified color targeting dyes.

[0042] [Figure 17d] FIG. 1 is a non-limiting diagram showing the color gamut of a color filter without and with the addition of modified dyes.

[0043] [Figure 18a] FIG. 1 is a non-limiting diagram of a display of simulated spectral power distributions of unmodified red, green, and blue dye ink pigment dispersions.

[0044] [Figure 18b] FIG. 1 is a non-limiting diagram of a display of simulated spectral power distributions of dye-modified blue and green dye ink pigment dispersions.

[0045] [Figure 19a] FIG. 13 is a non-limiting diagram of a display of simulated spectral power distributions of a blue pigment dye dispersion for each of the identified color target dyes. [Figure 19b] FIG. 13 is a non-limiting diagram of a display of simulated spectral power distributions of a red pigment dye dispersion for each of the identified color target dyes. [Figure 19c] FIG. 13 is a non-limiting diagram of a display of simulated spectral power distributions of a green pigment dye dispersion for each of the identified color target dyes.

[0046] [Figure 20a] FIG. 1 shows a non-limiting display of simulated spectral power distributions of red, blue and green pigment dispersions without modification.

[0047] [Figure 20b] FIG. 1 is a non-limiting diagram of a display of simulated spectral power distributions of dye-modified red, blue, and green pigment dye dispersions.

[0048] [Figure 21a] FIG. 1 is a non-limiting illustration of a display of simulated spectral power distribution of a blue dye pigment dispersion using dye at the backlight unit level. [Figure 21b] FIG. 1 is a non-limiting illustration of a display of simulated spectral power distribution of a red dye pigment dispersion using dye at the backlight unit level. [Figure 21c] FIG. 13 is a non-limiting illustration of a display of simulated spectral power distribution of a green dye pigment dispersion using dye at the backlight unit level.

[0049] [Figure 21d] FIG. 2 is a non-limiting diagram showing the color gamut of a color filter without and with the addition of a modified pigment.

[0050] [Figure 22a] FIG. 1 is a non-limiting diagram of a display of simulated spectral power distributions of unmodified red, green, and blue dye ink pigment dispersions.

[0051] [Figure 22b] FIG. 13 is a non-limiting diagram of a display of simulated spectral power distributions of dye-modified blue and green dye ink pigment dispersions.

[0052] [Figure 23a] FIG. 13 is a non-limiting diagram of a display of simulated spectral power distributions of a blue pigment dye dispersion for each of the identified color target dyes. [Figure 23b] FIG. 13 is a non-limiting diagram of a display of simulated spectral power distributions of a red pigment dye dispersion for each of the identified color target dyes. [Figure 23c] FIG. 13 is a non-limiting diagram of a display of simulated spectral power distributions of a green pigment dye dispersion for each of the identified color target dyes.

[0053] [Figure 24a]FIG. 1 shows a non-limiting display of simulated spectral power distributions of red, blue and green pigment dispersions without modification.

[0054] [Figure 24b] FIG. 1 is a non-limiting diagram of a display of simulated spectral power distributions of dye-modified red, blue, and green pigment dye dispersions.

[0055] [Figure 25a] FIG. 1 is a non-limiting illustration of a display of simulated spectral power distribution of a blue dye pigment dispersion using dye at the backlight unit level. [Figure 25b] FIG. 1 is a non-limiting illustration of a display of simulated spectral power distribution of a red dye pigment dispersion using dye at the backlight unit level. [Figure 25c] FIG. 13 is a non-limiting illustration of a display of simulated spectral power distribution of a green dye pigment dispersion using dye at the backlight unit level.

[0056] [Fig. 25d] FIG. 1 is a non-limiting illustration of the color gamut with and without the addition of modified dyes and pigments to a color filter.

[0057] [Figure 26] 1 is a schematic cross-sectional view of a display system according to the present disclosure.

[0058] [Figure 27] FIG. 1 is a schematic cross-sectional view of a display system showing standard pigments within each set of sub-pixels of a color display.

[0059] [Figure 28] 1 is a schematic cross-sectional view of a display system of the present disclosure showing the presence of an additional dye in one of the subpixel color sets.

[0060] [Figure 29] 1 is a schematic cross-sectional view of a display system of the present disclosure showing the presence of an additional dye in one of the subpixel color sets.

[0061] [Diagram 30] 1 is a schematic cross-sectional view of a display system of the present disclosure showing the presence of an additional dye in one of the subpixel color sets.

[0062] [Diagram 31] FIG. 2 is a schematic cross-sectional view of a display system of the present disclosure illustrating the presence of additional dyes in two subpixel color sets.

[0063] [Diagram 32] FIG. 2 is a schematic cross-sectional view of a display system of the present disclosure illustrating the presence of additional dyes in two subpixel color sets.

[0064] [Diagram 33] FIG. 2 is a schematic cross-sectional view of a display system of the present disclosure illustrating the presence of additional dyes in two subpixel color sets.

[0065] [Diagram 34] 1 is a schematic cross-sectional view of a display system of the present disclosure showing the additional presence of dyes in all of the sub-pixel color sets.

[0066] [Diagram 35] 1 is a schematic cross-sectional view of a display system of the present disclosure illustrating the further presence of a primary dye in all of the subpixel color sets and the presence of a secondary dye in one of the subpixel color sets.

[0067] [Diagram 36] 1 is a schematic cross-sectional view of a display system of the present disclosure illustrating the further presence of a primary dye in all of the subpixel color sets and the presence of a secondary dye in one of the subpixel color sets.

[0068] [Figure 37] 1 is a schematic cross-sectional view of a display system of the present disclosure illustrating the further presence of a primary dye in all of the subpixel color sets and the presence of a secondary dye in one of the subpixel color sets.

[0069] [Figure 38] FIG. 2 is a schematic cross-sectional view of a display system of the present disclosure illustrating the further presence of a primary dye in all of the subpixel color sets and the presence of a secondary dye in two of the subpixel color sets.

[0070] [Figure 39] FIG. 2 is a schematic cross-sectional view of a display system of the present disclosure illustrating the additional presence of a primary dye in all of the subpixel color sets and the presence of a secondary dye in two of the subpixel color sets.

[0071] [Diagram 40] FIG. 2 is a schematic cross-sectional view of a display system of the present disclosure illustrating the further presence of a primary dye in all of the subpixel color sets and the presence of a secondary dye in two of the subpixel color sets.

[0072] [Diagram 41] FIG. 2 is a schematic cross-sectional view of a display system of the present disclosure illustrating the further presence of a primary dye in all of the subpixel color sets and the presence of a secondary dye in all of the subpixel color sets.

[0073] [Diagram 42] FIG. 2 is a schematic cross-sectional view of a display system of the present disclosure illustrating the additional presence of primary color dyes in all of the subpixel color sets and the presence of dye enhancement compounds in all of the subpixel color sets.

[0074] [Figure 43a]2 is a schematic cross-sectional partial view of a display system of the present disclosure showing the further presence of dyes and dye enhancement compounds in one of the subpixel color sets.

[0075] [Figure 43b] 2 is a schematic cross-sectional partial view of a display system of the present disclosure showing the further presence of dyes and dye enhancement compounds in one of the subpixel color sets.

[0076] [Figure 43c] 2 is a schematic cross-sectional partial view of a display system of the present disclosure showing the further presence of dyes and dye enhancement compounds in one of the subpixel color sets.

[0077] [Figure 44a] 2 is a schematic partial cross-sectional view of a display system of the present disclosure illustrating the further presence of a primary dye, a secondary dye, and a dye enhancement compound in one of the subpixel color sets.

[0078] [Figure 44b] 2 is a schematic partial cross-sectional view of a display system of the present disclosure illustrating the further presence of a primary dye, a secondary dye, and a dye enhancement compound in one of the subpixel color sets.

[0079] [Fig. 44c] 2 is a schematic partial cross-sectional view of a display system of the present disclosure illustrating the further presence of a primary dye, a secondary dye, and a dye enhancement compound in one of the subpixel color sets.

[0080] [Diagram 45] 1 is a non-limiting graph showing dye absorption after heat stress in the absence of a dye enhancing compound.

[0081] [Diagram 46] FIG. 2 is a non-limiting graphical depiction of dye absorption after heat stress in the presence of a dye enhancing compound.

[0082] [Figure 47] 1 is a non-limiting graph showing dye absorbance over time for varying amounts of dye enhancing compound.

[0083] [Figure 48] 1 is a non-limiting graph showing dye absorbance after heat stress in the absence of a dye enhancing compound.

[0084] [Figure 49] FIG. 2 is a non-limiting graphical depiction of dye absorbance after heat stress in the presence of a dye enhancing compound.

[0085] [Figure 50] 1 is a non-limiting graph showing dye absorbance over time for varying amounts of dye enhancing compound.

[0086] [Figure 51] 1 is a non-limiting graph showing transmission across the wavelength spectrum from a device including a blue filter ink before and after being subjected to thermal stress.

[0087] [Figure 52] 1 is a non-limiting graph showing the transmission across the wavelength spectrum of devices including blue filter inks, dyes, and dye enhancement compounds before and after thermal stress.

[0088] [Figure 53] 1 is a non-limiting graph showing transmission across the wavelength spectrum from a device including a red filter ink before and after being subjected to thermal stress.

[0089] [Figure 54] 1 is a non-limiting graph showing the transmission across the wavelength spectrum of a device including a red filter ink, dye, and dye enhancement compound before and after thermal stress.

[0090] [Figure 55] 1 is a non-limiting graph showing transmission across the wavelength spectrum in the presence of a dye in a blue filter ink before and after thermal stress.

[0091] [Figure 56] 1 is a non-limiting graph showing transmission across the wavelength spectrum in the presence of a dye in a red filter ink before and after thermal stress. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0092] Various embodiments will be described in detail with reference to the drawings. Reference to various embodiments does not limit the scope of the claims appended hereto. Also, any examples described herein are not intended to be limiting, but merely illustrate some of the many possible embodiments of the appended claims. It is understood that various omissions and substitutions of equivalents are contemplated where the circumstances suggest or are expedient, but these are intended to encompass applications or embodiments without departing from the spirit or scope of the claims appended hereto. It should also be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting.

[0093] The present disclosure relates to the application of light filtering materials onto color filters in panel displays. Color filters are an important component in color reproduction in LCD TVs, computer monitors, and mobile devices such as smartphones and tablets. In a typical display panel, light emitted from LEDs is distributed by a backlight unit (BLU) to a series of functional layers and a color filter layer. The color filter layer is composed of an arrangement of three primary colors of light: red, blue, and green. In the present disclosure, dyes can be added to the color filters or color filter layers to tailor the filtering of light (especially high-energy blue light) to produce less harmful and more color-efficient blue light. Furthermore, the addition of dyes to the color filters or color filter layers can improve color gamut while minimizing luminance loss. Additional modifications to color filters are described herein that can provide additional benefits to color gamut and selectivity.

[0094] The disclosed color filter performance enhancements include dyes or one or more light absorbing materials that can absorb light of specific wavelengths and are used to modify the elements of the LCD display panel, particularly the color filters or backlight units (BLUs). The wavelength ranges of interest are 415 nm to about 435 nm for the blue light range, 490 nm to 570 nm for the green light range, and 620 nm and above for the red light range. Thus, various dyes with selected wavelength absorption characteristics are disclosed in this application. These selected dyes can modify the emission of the LED display panel to reduce the amount of blue light, even the amount of toxic blue light, with minimal impact on color properties such as brightness and color gamut. Examples of dyes with such properties include, but are not limited to, porphyrin-based compounds, coumarins, retinal pigments, phthalocyanine compounds, and other additives.

[0095] This disclosure describes the selective reduction of toxic blue light, primarily using dyes and / or pigments, and color enhancement with organic or metal complex dyes at the level of color filters. The unique properties of selected organic and metal complex dyes provide excellent absorption at desired wavelengths. However, there is secondary and undesirable absorption in other parts of the spectrum by these same dyes. The ability to filter where desired and avoid undesirable absorption and / or filtering is particularly suited to color filters and is unique to this disclosure. More specifically, this disclosure can reduce the toxicity of blue light and reduce overlap of color emissions. Color filters can also improve the color gamut of the resulting emission.

[0096] A backlight unit with the disclosed light management materials can absorb light in a first wavelength range and re-emit light in a second wavelength range having a different (e.g., higher) wavelength. The present disclosure contemplates light management materials that absorb blue light, particularly toxic blue light. Useful light conversion and light absorption materials are described, for example, in commonly owned U.S. Patent No. 10,901,125, entitled "Emission-Reducing Compounds for Electronic Devices," which is incorporated herein by reference.

[0097] The embodiment of FIG. 1 shows an exploded view of the various layers of a display system made up of a panel including a color filter 112 and a backlight unit ("BLU") 102, and each panel in its relative position. FIG. 1 shows one embodiment of a schematic diagram of an embodiment of a display system according to the present disclosure, showing where a light conversion layer or a light absorbing layer (blue filtering) layer can be inserted, in addition to possible color filter layers. In the figure, the color filter system 100 includes a backlight unit 102, which in some embodiments can include at least one other BLU component 104, such as a light guide, a reflector, a diffuser, a brightness enhancement film, a polarization control layer, etc. Typically, a light guide can include at least one other BLU component 104, such as a reflector, a diffuser, a brightness enhancement film, a polarization control layer, etc. It is a transparent or translucent, colorless block of material (glass or polymer) that can conduct light. A light guide can be made of a variety of materials, such as glass, polyacrylate (acrylic), polycarbonate, and other transparent polymers. The other display components disperse the light, spreading it throughout the backlight units 102-104 (and any other components that make up the backlight units).

[0098] More specifically, Figure 26 illustrates an example of a display system incorporating a backlight unit. The display system 300 may include a liquid crystal (LC) panel 350 and an illumination assembly 301 arranged to provide illumination light to the LC panel 350. The LC panel 350 includes an LC layer 352 arranged between panel plates 354. The plates 354 may include electrode structures and alignment layers on their inner surfaces to control the orientation of liquid crystals in the LC layer 352. These electrode structures may be arranged to define pixels of the LC panel. One or more of the plates 352 may also include color filters that impart color to the image displayed by the LC panel 350.

[0099] The LC panel 350 can be disposed between an upper absorbing polarizer 356 and a lower absorbing polarizer 358. The combination of the absorbing polarizers 356, 358 and the LC panel 350 can control the transmission of light from the illumination assembly 301 to a viewer, who is generally located at the top of FIG. 26 and generally looking down (with respect to FIG. 26) at the display system 300. The controller 304 can selectively activate pixels of the LC layer 352 to form an image seen by the viewer. One or more optional layers 357 can be provided over the upper absorbing polarizer 356, for example, to provide optical functionality and / or mechanical and / or environmental protection to the display.

[0100] The illumination assembly 301 may include a backlight 308 and one or more light management films 340 disposed between the backlight 308 and the LC panel 350. The backlight 308 of the display system 300 may include a light source 312 that generates light to illuminate the LC panel 350. The light source 312 may include any suitable illumination technology. In some embodiments, the light source 312 may be a light emitting diode (LED), and in some cases a white LED. The illustrated backlight 308 may be a "direct-lit" backlight in which an array of light sources 312 is disposed across most or all of the panel area behind the LC panel 350. However, the illustrated backlight 308 is merely schematic, and many other backlight configurations are possible. For example, some display systems may include a "side-lit" backlight in which light sources (such as LEDs) are disposed on one or more sides of a light guide, allowing light from the light sources to be distributed across most or all of the area of ​​the LC panel 350. The backlight 308 also includes a reflective substrate 302 for reflecting light from the light source 312 away from the LC panel 350. The reflective substrate 302 also helps to recycle light within the display system 300.

[0101] An arrangement of light management films 340, also referred to as a film stack, backlight film stack, or light management unit, can be disposed between the backlight 308 and the LC panel 350. The light management film 340 can affect illumination light propagating from the backlight 308 to improve the operation of the display system 300. It is noted that the light management film 340 need not include all of the components shown and described herein.

[0102] The arrangement of light management films 340 may include a diffuser plate 320. The diffuser plate 320 may diffuse the light received from the light source 312 and increase the uniformity of the illumination light incident on the LC panel 350. The diffuser plate 320 may be any suitable diffuser film or plate.

[0103] The light management unit 340 may include a reflective polarizer 342. The light source 312 typically produces unpolarized light, but the low absorption polarizer 358 may transmit only a single polarization state, so that approximately half of the light generated by the light source 312 may not be transmitted through the LC layer 352. However, the reflective polarizer 342 may be used to reflect light that is absorbed by the low absorption polarizer 358. This light may then be recycled by reflection between the reflective polarizer 342 and the underlying display components, including the reflective substrate 302. At least a portion of the light reflected by the reflective polarizer 342 may be depolarized and then returned to the reflective polarizer 342 in a polarization state that is transmitted through the reflective polarizer 342 and the low absorption polarizer 358 to the LC layer 352. In this manner, the use of the reflective polarizer 342 may increase the proportion of light emitted by the light source 312 that reaches the LC layer 352, resulting in a brighter display output. The reflective polarizer 342 may be any suitable type of reflective polarizer.

[0104] In some embodiments, a polarization control layer 344 can be provided between the diffuser 320 and the reflective polarizer 342. The polarization control layer 344 can be used to change the polarization of the light reflected from the reflective polarizer 342, thereby increasing the percentage of recycled light that passes through the reflective polarizer 342.

[0105] The light management film 340 arrangement also includes one or more brightness enhancing layers. Brightness enhancing layers include surface structures that redirect off-axis light closer to the axis of the display. This increases the amount of light that propagates on-axis through the LC layer 152, increasing the brightness of the image seen by the viewer. One example of a brightness enhancing layer is a prismatic brightness enhancing layer, which has a number of prismatic ridges that redirect the illumination light through refraction and reflection. An example of a prismatic brightness enhancing layer is BEF prismatic film available from 3M. Other types of brightness enhancing layers can incorporate non-prismatic structures.

[0106] In the embodiment shown in FIG. 26, a first brightness enhancing layer 346a is disposed between the reflective polarizer 342 and the liquid crystal panel 350. The prismatic brightness enhancing layer 346a typically provides optical enhancement in one dimension. An optional second brightness enhancing layer 346b may also be included in the light management layer arrangement 340, with its prismatic structure orthogonal to the prismatic structure of the first brightness enhancing layer 346a. Such a configuration increases the optical enhancement of the display system 300 in two dimensions. In other exemplary embodiments, the brightness enhancing layers 346a, 346b may be disposed between the backlight 308 and the reflective polarizer 342.

[0107] As a schematic diagram, it should be understood that the components of display system 300 are not shown to scale and are generally shown greatly exaggerated in thickness (top to bottom in FIG. 26) compared to width (side to side). Many elements of display system 300 (including, but not limited to, 302, 320, 342, 344, 346a, 346b, 352, 354, 356, and 357) can extend in two dimensions generally orthogonal to their thickness (i.e., perpendicular to the plane of FIG. 26) across an area approximately equal to the viewable area of ​​the display (which may be referred to as the "display area").

[0108] Returning to FIG. 1, the BLU 102 may be adjacent to or in close proximity to one or more polarizing filters 106 that pass light of certain polarizations and block light waves of other polarizations. In some embodiments, the polarizing filters 106 help reduce reflections and glare by filtering light that is polarized due to reflection from non-metallic surfaces. The purpose of the color filter backlight unit system 100 is to provide light for displaying images across the display by using color dyes in at least one layer to absorb the light passing through the system and distribute the light evenly across the two-dimensional plane of a portion of the BLU, such as a light guide plate.

[0109] In one embodiment, a thin film transistor (hereafter "TFT") array 108 is adjacent or proximate to the polarizer layer 106. The TFT array layer 108 can be a layered or thin arrangement and can have a photosensitive array and / or detector elements organized into small pixels. A pixel includes a photodiode (or a charge collector electrode and possibly a storage capacitor) and other elements that absorb electrons to create a charge. The TFT array layer 108 is controllable, which helps control the redraw output of the display seen by the user, and in some cases can be controlled to help reduce light transmission and color.

[0110] Near or adjacent to the TFT array layer 108 of the display system 100 is a liquid crystal panel 110. The display system 100 may optionally include a liquid crystal (LC) panel 110 and a lighting assembly arranged to provide illumination light to the LC panel (not shown). The LC panel may include an LC layer arranged between panel plates, which may include electrode structures and alignment layers on their inner surfaces to control the alignment of liquid crystals in the LC panel 110. These illuminators may be arranged to define pixels of the LC panel. Color filters 112 may also be included in one or more plates to impart color to the image displayed by the LC panel 110. In some embodiments, dyes may be included in the additional or existing plates. Dyes or sometimes pigments may be included to selectively improve the absorption and / or emission and transmission of light as seen by a user of the display system. Depending on the dyes or pigments included in the layers or plates, depending on the materials or compounds used and the amounts used, a X% decrease in brightness or light transmission will result in a reduction in the materials or compounds used and the amounts used. This improves the resulting color, glare, brightness, and other aspects of the resulting display light.

[0111] Display system 100 is merely exemplary, and the systems of the present disclosure are not limited to use in systems similar to display system 100. The systems of the present disclosure may also be beneficially used in other types of display systems that do not necessarily involve liquid crystal display technology.

[0112] The display system may include another layer that is a color filter. The color filter layer 112 includes an array of pixels, where each pixel is made up of color subpixels (e.g., red subpixels, green subpixels, and blue subpixels). As shown in FIG. 1, a black matrix may separate the spaces between each subpixel. The red, green, and blue subpixels may obtain their color using inks and pigments suspended in the matrix. In this disclosure, the term pigment is frequently used to describe the color provided to the subpixels, but this term is expected to include what is also known in the art as "ink." Thus, unless otherwise stated herein, both pigment and ink refer to the color used to create a subpixel of a particular color.

[0113] For example, FIG. 27 is a schematic cross-sectional view of a display system showing standard pigments within each set of subpixels of a color display. Specifically, the display system may include a backlight unit 402 with a reflective substrate 404 and a light source 406. Adjacent to the backlight unit 402 is a glass substrate 408 followed by an electrode 410. A liquid crystal layer 412 may be disposed between the electrode 410 and an electrode 414. Adjacent to the electrode 414 is a color filter with a black matrix 416 that separates the spaces between the subpixels 418. In some cases, as shown in FIGS. 27-34, the black matrix 416 may be interspersed between at least some of the subpixels 418. However, in other cases, the black matrix 416 may be a separate layer adjacent to the subpixels 418. A glass substrate 420 may be disposed adjacent to the black matrix 416 and / or the subpixels 418, through which transmitted light 424 passes to the user's eye. In some embodiments, additional layers may be present, such as, but not limited to, one or more polarizing layers, a diffusing layer, one or more brightness enhancing layers, or any other display layer.

[0114] 27, each subpixel 418 can be comprised of a matrix that includes a colored pigment / ink 422 suspended within the matrix that provides the color of that particular subpixel. For example, red subpixel 418a can have red pigment / ink 422a suspended within its matrix, green subpixel 418b can have green pigment / ink 422b suspended within its matrix, and blue subpixel 418c can have blue pigment / ink 422c suspended within its matrix.

[0115] The color filter layer 112 may further include dyes (such as soluble dyes), pigments, compounds, or any combination thereof that may affect the color transmittance of the color filter layer 112. The effect depends on the type of dye, pigment, or compound and the amount present. In one example, the toxicity of blue light may be reduced. The color may affect the resulting display, with blue dyes reducing the transmittance of blue light, green dyes reducing the transmittance of green light, and red dyes reducing the transmittance of red light.

[0116] When dyes are incorporated into the color filters 112, the inherent properties of the color filters 112 can improve the color gamut and effectively reduce the toxicity of blue light. In some cases, the color filters 112 can modify the emission at the light level. When dyes such as blue dyes are added, secondary absorption may occur, and adding blue dyes to the color filters 112 will primarily affect the blue color. Also, the three sub-pixels (e.g., red, green, blue) within each pixel will correspond or be affected depending on the dyes selected and their placement.

[0117] In some embodiments, blue dyes may be added to layers such as color filters 112 and / or pixels or subpixels with layers to prevent secondary absorption between other light regions. The dyes improve display quality and light transmission by reducing light leakage (such as green light entering blue pixels and / or blue light entering green pixels) and narrowing the color gamut. Thus, dyes at wavelengths above 500 nm in blue pixels reduce light leakage into green, and dyes near 491 nm in green pixels reduce light leakage into blue wavelengths 575 nm. Similarly, dyes may be added to red pixels to prevent green light from leaking into red light. Additionally, color control or limitation can reduce toxicity by widening the color gamut without brightness loss.

[0118] Dyes may be added to specific locations and layers of the display stack. In one embodiment, a blue light filtering dye can be added to the blue subpixels (to filter out harmful blue light). The blue dye filters light on the short wavelength side of the blue range, the blue dye filters light on the long wavelength side of the blue range, the green dye filters light on the short wavelength side of the green range, the green dye filters light on the long wavelength side of the green range, and the red dye can filter light in the red wavelength range. All of these function to expand the color gamut and separate the color peaks. Thus, different dye selections affect the resulting wavelengths. Dyes may result in different colors such as short wavelength blue, long wavelength blue, short wavelength green, long wavelength green, and short wavelength red.

[0119] 28-41 show various examples of dyes that are incorporated directly into the pixels and / or subpixels of the color filter (e.g., dyes that are part of the solution on a molecular basis, rather than dissolved in and adjacent to the subpixel matrix). In some embodiments, additional molecules can be added to the subpixels along with the dyes to improve performance of the final color filter. These performance improvements can include, but are not limited to, optimal coating viscosities that allow for coating optimization and facilitate component compatibility, more robust final coatings that are solvent and scratch resistant, and dye improvements that keep dyes 426a-c, 428, 430, and / or 432 stable when exposed to heat and light.

[0120] 28 illustrates color filter subpixels 418, where each subpixel includes a corresponding pigment to impart its color (i.e., red pigment 422a forms red subpixel 418a, green pigment 422b forms green subpixel 418b, and blue pigment 422c forms blue subpixel 418c), and further, blue subpixel 418c can include a primary dye 426c that can absorb light in a specific wavelength range at or near the blue wavelength range, such as 400nm-430nm, 410nm-430nm, 415nm-435nm, 415nm-455nm, 490nm-520nm, and / or 510nm-530nm. In some cases, a specific wavelength, such as 450nm, may be targeted to remove dyes that may have high transmittance and adversely affect color gamut. Thus, as shown in Figure 28, a blue subpixel 418c can include a blue pigment 422c, which gives the subpixel its color, and a primary color dye 426c, which absorbs at least a portion of the blue light spectrum. The blue pigment 422c can be suspended in a matrix for the blue subpixel 418c, while the primary color dye 426c can be dissolved in the matrix and become part of the matrix solution.

[0121] Similarly, FIG. 29 illustrates color filter subpixels 418, each of which includes a corresponding pigment that gives it its color (as described above), and further includes a green subpixel 418b. The green subpixel 418b may include a primary color dye 426b that can absorb light in a particular wavelength range within or near the green wavelength range. For example, but not limited to, 445 nm to 455 nm, 470 nm to 495 nm, 470 nm to 500 nm, 490 nm to 570 nm, 520 nm to 550 nm, 590 nm to 640 nm, and / or 600 nm to 640 nm. In some cases, specific wavelengths may be targeted, such as, but not limited to, 530 nm, to remove pigments that may have high transmission and adversely affect color gamut. Thus, as shown in FIG. 29, the green subpixel 418b may include a green pigment 422b that gives the subpixel its color, and a primary color dye 426b that absorbs at least a portion of the spectrum of green light. The green pigment 422b may be suspended within the matrix of the green subpixel 418b, while the primary color dye 426b may be dissolved within the matrix and become part of the matrix solution.

[0122] Similarly, FIG. 30 illustrates color filter subpixels 418, each of which includes a corresponding pigment to give it its color (as discussed above), and further includes a red subpixel 418a that may include a primary dye 426a capable of absorbing light in a particular wavelength range within or near a red wavelength range, such as 440 nm to 460 nm, 520 nm to 540 nm, 570 nm to 600 nm, 580 nm to 600 nm, and / or 580 nm to 620 nm. Thus, as shown in FIG. 3, the red subpixel 418a may include a red pigment 422a that gives the subpixel its color, and a primary dye 426a that absorbs at least a portion of the spectrum of red light. The red pigment 422a may be suspended within the matrix of the red subpixel 418a, while the primary dye 426a may be dissolved within the matrix and become part of the matrix solution.

[0123] As shown in Figures 31-34, some embodiments of the disclosed color filters may include dyes in two or more of the corresponding subpixels. For example, as shown in Figure 31, the blue subpixel 418c may include a primary color dye 426c, and the green subpixel 418b may include a primary color dye 426b. In another example shown in Figure 32, the blue subpixel 418c may include a primary color dye 426c, and the red subpixel 418a may include a primary color dye 426a. As shown in Figure 33, the green subpixel 418b may include a primary color dye 426b, and the red subpixel 418a may include a primary color dye 426a. Also, as shown in Figure 34, the green subpixel 418b may include a primary color dye 426b, and the red subpixel 418a may include a primary color dye 426a. As shown in FIG. 34, all three subpixels 418a-418c include primary color dyes, with blue subpixel 418c including primary color dye 426c, green subpixel 418b including primary color dye 426b, and red subpixel 418a including primary color dye 426a. The absorption ranges of these primary color dyes 426a-426c are similar to those described above, and depending on the selected absorption ranges, the primary color dyes 426a-426c can reduce the transmission of harmful / toxic blue light (blue light between 415 nm and 435 nm), improve the color gamut of the resulting emission, reduce light leakage / overlap of color emission between subpixels (i.e., blue subpixels do not leak green or red light, green subpixels do not leak blue or red light, red subpixels do not leak blue or green light, etc.), and separate color peaks to brighten the primary colors. Specific examples of these improvements are described in more detail below and further illustrated in the figures.

[0124] In some embodiments, one or more of the subpixels 418a-418c may include a corresponding primary dye 426a-426c, and further, one or more of the subpixels 418a-418c may include a secondary dye. For example, as shown in FIG. 35, the blue subpixel 418c may include a primary dye 426c and a secondary dye 430, where both dyes 426c and 430 are part of a solution that is dissolved in the subpixel matrix to create the blue subpixel 418c. The secondary dye 430 may be a dye that absorbs in a different wavelength range than the primary dye 426c, which absorbs near or within the blue wavelength range. More specifically, the primary dye 426c absorbs in a short wavelength blue range, such as 400 nm to 430 nm, and the secondary dye 430 absorbs in a long wavelength blue range, such as 490 nm to 520 nm, to aid in color correction or leakage reduction. Alternatively, the secondary dye 430 absorbs at a different color wavelength, such as green, to aid in reducing leakage of non-blue light through the blue subpixel 418c. Thus, the secondary dye 430 serves to separate the color peaks between the blue, green, and / or red peaks. Although the secondary dye 430 is sometimes referred to herein in the singular, it is contemplated that one or more dyes may comprise a secondary dye.

[0125] In another example, as shown in FIG. 36, the green subpixel 418b includes a primary dye 426b and a secondary dye 428, where both dyes 426b and 428 are dissolved in the subpixel matrix and are part of the solution creating the green subpixel 418b. The secondary dye 428 may be a dye that absorbs in a different wavelength range than the primary dye 426b, which absorbs near or within the green wavelength range. More specifically, the primary dye 426b may absorb in a short wavelength green range, such as 470 nm to 500 nm, and the secondary dye 428 may absorb in a long wavelength green range, such as 565 nm to 590 nm or 600 nm to 640 nm, to assist in color correction or leakage reduction. Alternatively, the secondary dye 428 may absorb a different color wavelength, such as blue or red, to help reduce leakage of non-green light through the green subpixel 418b. Thus, the secondary dye 428 helps separate color peaks between the blue, green, and / or red peaks. Although secondary dye 428 is sometimes referred to herein in the singular, it is contemplated that one or more dyes may comprise a secondary dye.

[0126] Further, as shown in FIG. 37, red subpixel 418a includes a primary dye 426a and a secondary dye 432, where both dyes 426a and 432 are dissolved in the subpixel matrix and are part of the solution creating red subpixel 418a. Secondary dye 432 may be a dye that absorbs at a different wavelength range than primary dye 426a, which absorbs near or within the red wavelength range. More specifically, primary dye 426a may absorb in a short wavelength red range, such as 570 nm to 600 nm, and secondary dye 432 may absorb in a long wavelength red range, such as 620 nm to 600 nm, to aid in color correction. Alternatively, secondary dye 432 may absorb at a different color wavelength, such as blue or green, to aid in reducing leakage of non-red light through red subpixel 418a. For example, many red filter inks transmit light in the wavelength range of 440 nm to 460 nm, so incorporating a secondary dye 432 into a subpixel can block that wavelength range and sharpen the color emission from the display. The secondary dye 432 thus serves to separate the color peaks between the blue, green, and / or red peaks. Although the secondary dye 432 is sometimes referred to herein in the singular, it is envisioned that one or more dyes may comprise the secondary dye.

[0127] Although an example is shown here in which secondary dyes 430, 428, 432 are present in a color filter having all three primary dyes 426a-c, secondary dyes may be present in a color filter regardless of whether primary dyes are present in the non-corresponding subpixels 418a-418c. For example, secondary dye 430 may be present in blue subpixel 418c even if there are no primary dyes 426a or 426b corresponding to red subpixel 418a and / or green subpixel 418b. Similarly, secondary dye 428 may be present in green subpixel 418b even if there are no primary dyes 426a or 426c corresponding to red subpixel 418a and / or blue subpixel 418c, and secondary dye 432 may be present in red subpixel 418a even if there are no primary dyes 426b or 426c corresponding to green subpixel 418b and / or blue subpixel 418c.

[0128] Additionally, some embodiments of the disclosed color filters may include a secondary dye in two or more of the corresponding subpixels, as shown in Figures 38-41. For example, as shown in Figure 38, blue subpixel 418c may include secondary dye 430 and green subpixel 418b may include secondary dye 428. In another example shown in Figure 39, blue subpixel 418c may include secondary dye 430 and red subpixel 418a may include secondary dye 432. As shown in Figure 40, green subpixel 418b may include secondary dye 428 and red subpixel 418a may include secondary dye 432. Also, as shown in Figure 41, secondary dyes may be included in all three subpixels 418a-418c, such that blue subpixel 418c includes secondary dye 430, green subpixel 418b includes secondary dye 428, and red subpixel 418a includes secondary dye 432.

[0129] In some embodiments, the dyes added to the subpixels of the color filters are heat resistant / stable and can maintain their ability to absorb the intended wavelength range even after exposure to high temperatures (e.g., 200-250° C.) for extended periods of time (e.g., 2-3 hours). More specifically, light transmitted from a display incorporating the disclosed color filters and dyes 426a-426c and / or secondary dyes 430, 428, 432 can minimally change location on the color gamut chart, with the X and Y coordinates / values ​​shifting no more than 1% along the X axis and no more than 1% along the Y axis. In some cases, the shift along one or both axes is 0.6% or less. For example, the shift along the Y axis for blue subpixels is 0.2-0.3%. The shift along the Y axis for red subpixels can be 0.5-0.6%.

[0130] As mentioned above, additional molecules can be added to the subpixels along with the dyes to improve the performance of the final color filter. These molecules / additives are referred to here as dye-enhancing compounds and include photoinitiators, co-initiators, monomers, stabilizers, co-initiators, etc.

[0131] Photoinitiators include, but are not limited to, oxime compounds, ketones, triazine compounds, phosphine oxide compounds, biimidazole compounds, benzoin compounds, quinone compounds, thioxanthone compounds, triazine-based photoinitiators, and coumarin compounds.

[0132] Examples of the polymerization initiator aid include, but are not limited to, amine compounds, alkoxyanthracene compounds, thioxanthone compounds, carboxylic acid compounds, amide compounds, triethylbenzylammonium chloride, imidazole compounds, triphenylphosphine, and triazine compounds.

[0133] The monomers are composed of unsaturated monocarboxylic acids and may include, but are not limited to, acrylic acid, methacrylic acid, crotonic acid, α-chloroacrylic acid, cinnamic acid, dicarboxylic acid diesters, bicyclo compounds, and the like. The unsaturated dicarboxylic acids may include, for example, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, and the like. The unsaturated polycarboxylic acids may be anhydrides of the acids. Additionally, the unsaturated polycarboxylic acids may be monoesters thereof. Additionally, the unsaturated polycarboxylic acids may be monoacrylates having polymeric dicarboxylic acid groups at both ends thereof. In some embodiments, other types of multifunctional monomers include, but are not limited to, one or more of trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, propoxylated dipentaerythritol hexa(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0134] Stabilizers include, but are not limited to, antioxidants such as hindered phenols, hindered amines, phosphorus-based antioxidants, sulfide-based antioxidants, or combinations thereof. There may be one or more primary antioxidants and / or one or more secondary antioxidants present in the disclosed subpixels. In some cases, the antioxidant may have a phenolic antioxidant functional group and a phosphorus-based antioxidant functional group, or both a phenolic antioxidant functional group and a sulfur-based antioxidant functional group in one molecule. It is expected that the phenolic antioxidants can be used independently or two or more types can be used together. Similarly, the amine-based antioxidants can be used independently or two or more types can be used together. The adverse effects of the inclusion of stabilizers can be countered by photoinitiators or co-initiators.

[0135] In some embodiments, the dyes may not be heat stable by themselves, so dye strengthening compounds can be added to the subpixels of the color filter to increase the heat resistance / stability of the dyes. The dye strengthening compounds can protect the dyes so that they maintain their ability to absorb the intended wavelength range even after exposure to high temperatures (e.g., 200-250° C.) for extended periods of time (e.g., 2-3 hours).

[0136] More specifically, many dyes are not heat resistant and may experience a decrease in light absorption levels over time. For example, as shown in Figure 1, as can be seen from Figures 45 and 48, after only 30 minutes of thermal stress, a dye with strong absorption that typically peaks near 435 nm (e.g., a dye with an absorption range of 400 nm to 450 nm, a full width at half maximum of 50 nm or less, an absorbance peak of 425 nm to 440 nm, and a low transmittance of 35% to 45% at the peak absorbance) may experience a 20% to 40% higher transmittance at the peak absorbance point (i.e., a dye that may have a 35% to 40% light transmittance from the device near 435 nm before thermal stress may experience a 75% to 80% transmittance after thermal stress, and a dye that may have a 40% to 45% light transmittance from the device before thermal stress may experience a 60% to 65% transmittance after thermal stress). As shown in Figure 45 and Figure 48, after 180 minutes of thermal stress, the same dyes have less noticeable absorption of blue light and the transmission curve is relatively flat across the visible light spectrum (i.e., less than 5% variation in transmission). In some cases, these dyes may have secondary absorption peaks between 530-580 nm (with full width at half maximum of 50 nm or less and peaks near 545-560 nm) that are also adversely affected by thermal stress. With these dyes, the light transmission from the device before thermal stress can be around 95% at these green absorption peaks, and after 30 minutes of thermal stress the transmission can be close to 97-99%, and after 180 minutes of thermal stress the transmission can be close to 100%.

[0137] Therefore, as mentioned above, a dye enhancing compound can be added to mitigate the decrease in the dye's absorption ability. As shown in Figures 46 and 49, when comparing the transmission and absorption characteristics before and after the thermal test when a dye enhancing compound is added, the transmission and absorption characteristics of the dye are relatively unchanged. For example, as shown in Figure 46, the transmittance from a device containing a composite dye and a dye enhancing compound in the color filter is 35-40% (full width at half maximum is 50 nm or less, peak absorbance is 425-440 nm, and absorption range is 400-450 nm) before thermal stress and remains at 35-40% after 30 minutes of thermal stress. After 180 minutes of thermal stress, the transmittance from a device containing a composite dye and a dye enhancing compound in the color filter moves minimally to 40-45%. Thus, the overall transmittance in the blue range from a device combining a dye and a dye enhancing compound in the color filter can change within 10% between the original value and the value after thermal stress. As shown in Figure 46, the transmittance in the green range from a device that combines dye and dye-enhancing compounds in the color filters (absorption at 530-580 nm, half-width less than 50 nm, peak near 545-560 nm) is 93-97% before thermal stress and remains at 93-97% after 30 minutes and 180 minutes of thermal stress. As shown in the figure, the absorption level in the green range may not change at all.

[0138] In another example, as shown in FIG. 49, the transmittance from a device with dye and dye-enhancing compounds in the color filters is 30-35% before thermal stress (full width at half maximum 50 nm or less, peak absorbance at 425-440 nm, absorption range 400-450 nm) and remains at 30-35% after 30 minutes of thermal stress. After 180 minutes of thermal stress, the transmittance from a device with dye and dye-enhancing compounds in the color filters increases to a minimum of 35-40%. Thus, the overall transmittance in the blue range from a device with dye and dye-enhancing compounds in the color filters does not change by more than 10% between the original value and the value after thermal stress. As shown in Figure 49, the transmittance in the green range from a device that combines dye and dye-enhancing compounds in the color filters (absorption at 530-580 nm, full width at half maximum less than 50 nm, peak near 545-560 nm) is 92-96% before thermal stress and may remain at 92-96% after 30 minutes and 180 minutes of thermal stress. As shown in the figure, the absorption level in the green range may not change at all.

[0139] To prevent the absorption value from decreasing, the amount of dye enhancing compound incorporated in the subpixel may be 2-5%. The addition of dye enhancing compound (e.g., 5%) increases the absorption capacity of the dye, but amounts as low as 2% can have a positive effect. For example, as shown in FIG. 47, 2% of the dye in one embodiment combined with the dye enhancing compound reduces the absorption capacity of the dye by about 10-15%, 3% reduces the absorption capacity of the dye by less than 6%, and 5% reduces the absorption capacity by less than 3%. As shown in FIG. 50, as little as 1% of another embodiment of the dye enhancing compound reduces the absorption capacity of the dye by about 4-7%. Similarly, 2% of the dye enhancing compound combined with that embodiment of the dye can cause the dye to lose about 4-7% of its absorption capacity, and 5% can cause less than 3% loss of absorption capacity. As shown in both FIG. 47 and 50, without the dye enhancing compound, the dye can lose all of its absorption capacity after 100-150 minutes (e.g., after 125 minutes).

[0140] Figures 45-50 show the absorption efficiency of the dye in combination with the dye enhancing compound even after thermal stress, while Figures 52 and 54 show the absorption efficiency when a combination of the dye and the dye enhancing compound is added to the color filter ink. Specifically, as shown in Figure 51, the transmission of light through the blue color filter ink is only minimally affected even after thermal stress. However, the blue color filter ink has a high transmission of blue wavelengths between 400-500 nm. Therefore, as described further herein, a blue dye can be added to the blue subpixels of the color filter to absorb harmful blue wavelengths. As shown in Figure 52, the addition of the blue dye and the dye enhancing compound to the color filter ink of the blue subpixels significantly increases the absorption of blue wavelengths between 410 nm and 46 nm. Furthermore, even after thermal stress, the absorption properties of the dye are only minimally affected, remaining similar (e.g., within 5%) in the range of 410-460 nm.

[0141] Similarly, as shown in FIG. 53, there is minimal transmission of light through the red color filter ink in the blue wavelength range after thermal stress. As further shown in FIG. 53, there remains some blue light transmitted through the red color filter ink in the wavelength range of 380 nm to 460 nm. Thus, as further described herein, blue dyes can be added to the red subpixels of the color filter to absorb blue wavelengths and reduce leakage of blue wavelengths into the red subpixels to increase the vividness of the colors emitted by the display. Thus, it is desirable to absorb lower spectral wavelengths in the red subpixels. As shown in FIG. 54, if blue dyes and dye enhancing compounds are added to the color filter ink of the red subpixels, there is increased absorption of blue wavelengths from 400 nm to 470 nm and very little light is transmitted (e.g., less than 2%) from 420 nm to 470 nm. Furthermore, after thermal stress, the absorption characteristics of the dye are only minimally affected, and a similar amount of absorption remains in the range of 420 nm to 470 nm (e.g., within 1%).

[0142] Additionally, light transmitted from a display incorporating the disclosed color filters and dyes 426a-426c, secondary dyes 430, 428, 432, and / or dye enhancement compounds 434a-434c may experience minimal change in location on the color gamut chart, with the X and Y coordinates / values ​​shifting by no more than 0.75% along the X axis and no more than 0.75% along the Y axis, in some cases shifting no more than 0.6% along either or both axes.

[0143] For example, in one embodiment of blue subpixel 418c having blue ink 422c, the incorporation of dye enhancing compound 434c along with dye 426c and / or secondary dye 430 allows the subpixel to resist movement along the Y-axis of the color gamut chart after heat treatment, and the transmitted light can move along the Y-axis by no more than 0.1-0.5% (e.g., 0.2-0.3%). Additionally, ΔEab is 2-3 (e.g., 2.2-2.4, more specifically 2.3). In one embodiment, the dye and dye enhancing compound limit movement in the color gamut chart to Δx of 0.0002, Δy of 0.0030, ΔY,% of 0.219%, and ΔEab of 2.2986.

[0144] Similarly, in one embodiment of red subpixel 418a having red ink 422a, the incorporation of dye enhancing compound 434a along with dye 426a and / or secondary dye 432 enables the subpixel to resist movement along the Y-axis of the color gamut chart after thermal processing, such that the transmitted light moves no more than 0.3-0.8% (e.g., 0.45-0.55%) along the Y-axis. Additionally, ΔEab is 0.5-1.5 (e.g., 0.75-0.95, more specifically 0.9). In one embodiment, the dye and dye enhancing compound limit movement in the color gamut chart to Δx -0.0020, ΔY 0.0008, ΔY,% 0.504%, and ΔEab 0.8637.

[0145] Figures 55-56 show examples of transmittance measurements where the effect of the dye on absorption is decoupled from the presence of the color filter ink and dye enhancing compound. Thus, Figures 55-56 show that the dye performs as expected and changes are negligible after being combined with the dye enhancing compound and color filter ink and subjected to thermal stress. Specifically, the ability of the dye in the blue color filter ink to absorb light between 400nm and 460nm changes very little before and after thermal testing (e.g., less than 5% at the peak absorption wavelength). Similarly, the ability of the dye in the red color filter ink to absorb light between 400nm and 460nm changes very little before and after thermal testing (e.g., less than 10% at the peak absorption wavelength).

[0146] These dye enhancement compounds can be present in any subpixel that contains a light absorbing dye. For example, as shown in Figure 42, red, green, and blue subpixels 418a-418c are shown having pigments 422a-422c, absorbing dyes 426a-426c, and dye enhancement compounds 434a-434c, respectively. It should be noted that while dye enhancement compounds 434a-434c are shown as a single compound in the figure, they could be one or more compounds.

[0147] 43a-43c show example embodiments in which only one of the subpixel color sets (blue subpixel 418c in FIG. 43a, green subpixel 418b in FIG. 43b, and red subpixel 418a in FIG. 43c) has a corresponding absorbing dye 426a-426c, and therefore the dye enhancement compound 434a-434c of that corresponding subpixel color set is the only dye enhancement compound (or combination of compounds) present in the color filter. In embodiments in which the blue, green, or red subpixels include more than one dye, as shown in FIG. 44a-44c, the dye enhancement compound (or combination of compounds) 434a-434c may also be included. The examples shown in FIG. 43a-43c show example embodiments in which only the absorbing dyes 426a-426c have a corresponding absorbing dye 426a-426c. Although Figures 43-44 show only an embodiment having one subpixel with a dye and a dye enhancement compound, it is anticipated that some embodiments of the disclosed color filters will have multiple subpixel color sets with dyes, where the dye enhancement compound is present in one or more of the subpixel color sets in which the dye is disposed. More specifically, the embodiments shown in Figures 43a-43c and 44a-44c, and Figures 28-30 and 35-37, may be used "in combination" with one another.

[0148] For example, an embodiment may incorporate the dyes and compounds shown in Figures 44a and 44b, where one or more dyes 426b-426c, 430, 428 in the blue subpixel 418c and the green subpixel 418b have corresponding dye enhancement compounds 434c, 434b in one or both of the blue and green subpixels, and the dye enhancement compounds may be comprised of one or more different types of dye enhancement compounds. Similarly, in embodiments with dyes 426c, 426a, 430, 432 in the blue and red subpixels 418c, 418a (or dyes 426b, 426a, 428, 432 in the green and red subpixels 418b, 418a), one or both of the blue and red subpixels may be provided with dye enhancement compounds 434a, 434c (or dye enhancement compounds 434b, 434a in one or both of the green and red subpixels), which may be comprised of one or more different types of dye enhancement compounds. This effectively becomes a combination of Figures 44a and 44c (blue and red subpixels 418c, 418a have dyes 426, 426a and compounds 434c, 434a) and Figures 44b and 44c (green and red subpixels 418b, 418a have dyes 426b, 426a and compounds 434b, 434a). In another example, one embodiment of a color filter might have a single dye 426c and dye enhancement compound 434c in the blue subpixel 418c (Figure 43a) and two dyes 426b, 428 and no enhancement compound in the green subpixel 418b (Figure 36).

[0149] It is envisioned that the disclosed color filters may further be combined with all of the embodiments of Figures 28-30, 35-37, 43a-43c, and 44a-44c. Thus, the embodiment of Figure 28 may be combined with any of the embodiments of Figures 29-30, 36-37, 43b-43c, and 44b-44c, the embodiment of Figure 29 may be combined with any of the embodiments of Figures 28, 30, 35, 37, 43a, 43c, 44a, and 44a, the embodiment of Figure 30 may be combined with any of the embodiments of Figures 28-29, 35-36, 43a-43b, and 44a-44b, and the embodiment of Figure 35 may be combined with any of the embodiments of Figures 36-38, 47-50, and 48-52. The embodiment of Fig. 36 can be combined with any of the embodiments of Figs. 28, 30, 35, 37, 43a, 43c, 44a, and 44a, the embodiment of Fig. 37 can be combined with any of the embodiments of Figs. 28-29, 35-36, 43a-43b, and 44a-44b, and the embodiment of Fig. 43a can be combined with any of the embodiments of Figs. 29-30, 36-37, 43b-43c, and 44b-44c. the embodiment of Fig. 43b can be combined with any of the embodiments of Figs. 28, 30, 35, 37, 43a, 43c, 44a, and 44a; the embodiment of Fig. 38 can be combined with any of the embodiments of Figs. 38-40, 35, 37, 43a, 43c, 44a, and 44a; and the embodiment of Fig. 39 can be combined with any of the embodiments of Figs. 39-40, 35, 37, 43a, 43c, 44a, and 44a. FIG. 43c can be combined with any of the embodiments of FIGS. 28-29, 35-36, 43a-43b, and 44a-44b; the embodiment of FIG. 44a can be combined with any of the embodiments of FIGS. 29-30, 36-37, 43b-43c, and 44b-44c; the embodiment of FIG. 44b can be combined with any of the embodiments of FIGS. 28, 30, 35, 37, 43a, 43c, 44a, and 44a; and the embodiment of FIG. 44c can be combined with any of the embodiments of FIGS. 28-29, 35-36, 43a-43b, and 44a-b.

[0150] In some embodiments, there may be a second polarizing layer (or more) 114. The polarizing layer 114 passes light of a particular polarization received after the color filters and blocks light waves of other polarizations. In other words, the polarizing layer reduces glare and helps form the image seen by the user of the computing device. In some embodiments, next to or adjacent to the polarizing layer, there may be a glass layer or glass cover 116. This layer not only protects the layers of the display but also provides additional control over glare and light transmission. In some embodiments, a multi-stack display configuration not only improves the color of the display but also reduces glare. Different layers control the transmission and emission of light as the emitted light passes through different stack layers. Thus, modifying the color filters 112 reduces toxic blue light and improves the color quality of the display, thereby improving adverse effects and health for the user.

[0151] In other embodiments, a light emitting diode array (not shown) can be arranged in strips as the light source, with light entering the backlight unit 102 from one edge of the light guide plate. Alternatively, the light emitting diode array can be positioned below the light guide plate. The light guide plate can be adjacent to a reflector plate (not shown) on one or more sides to direct the light from the light emitting diode array upwards and through the backlight unit 102. The light guide plate can be positioned between the reflector plate and the diffuser plate. The effect of this type of structure is to redirect the light from the light source to the edge of the display screen and spread it evenly across the display surface.

[0152] In embodiments where a diffuser is present (not shown), the diffuser can distribute the light evenly and eliminate bright spots. Diffusers can be of various types, such as holographic, white diffused glass, and frosted glass. The diffuser can be translucent and can reflect light in various directions. A brightness enhancing layer (not shown) can be present, which can be a prismatic brightness enhancing film. Adjacent to the backlight unit 102 (on top of which can be the first or second brightness enhancing layer) can be a first polarizing filter 106 (polarizing filter 114 may also be present in the display stack) that passes light of a particular polarization and blocks light waves of other polarizations. In some embodiments, the polarizing filter can help reduce reflections and glare by filtering light that is polarized due to reflection from non-metallic surfaces. The purpose of the backlight unit 102 is to distribute light evenly across the two-dimensional plane of the light guide plate and provide light for displaying images across the display.

[0153] As noted above, Figure 1 is a schematic exploded view of an embodiment of an exemplary display system 100 in which the display system of the present invention may be advantageously used. Display system 100 may be used, for example, in a liquid crystal display (LCD monitor, LCD-TV, handheld, tablet, laptop, headset, VR / XR / AR display equipment, or other computing device. However, display system 100 of Figure 1 is merely exemplary, and systems of the present invention are not limited to use in systems similar to display system 100. Systems of the present invention may be advantageously used in a variety of other display systems that do not necessarily include liquid crystal display technology.

[0154] In the present disclosure, several examples of dyes (see Table 1) that absorb in the blue, red, and green ranges can be used to modify the color filter 112. Modifying the blue, red, and green emissions can be a more precise way to filter out toxic blue light while minimizing brightness loss and improving the resulting color gamut.

[0155] As further described herein, the blue, green, and red dyes can be applied at the level of the color filter or backlight unit (BLU). When applied to the color filter, the dyes are confined to the corresponding subpixels. More specifically, the color filter is composed of blue, green, and red subpixels, and the dyes can be applied accordingly. Thus, the blue dyes can be applied to the blue subpixels, the green dyes can be applied to the green subpixels, and the red dyes can be applied to the red subpixels. There can be many combinations of application. For example, the blue and green dyes can be applied to the corresponding subpixels, the blue and red dyes can be applied to the corresponding subpixels, the green and red dyes can be applied to the corresponding subpixels, or all three dyes can be applied to the corresponding subpixels. Application of dyes to subpixels, and combinations of the above, can help reduce toxic blue light emitted from the display device and can also help improve brightness and color gamut.

[0156] [Table 1] Table 1: Dyes and associated maximum absorption wavelengths (nm) Example of dys:Dye example;Dye Name:Dye name;Absorbing wavelengths (nm);Absorbing wavelengths (nm)

[0157] Application of select dyes and / or dye formulations to the color filters or backlight units of the disclosed display panels can modify said data to relate to spectral emission, luminance, blue toxicity ratio, blue phototoxicity factor, and ranges covering standard color gamut systems such as Adobe RGB, DCI-P3, sRGB, BT.2020, NTSC, etc., as shown in Table 2. Table 2 is one embodiment of one type of display monitor that was measured. Many different types of monitors are available and the measured values ​​will vary depending on the display light measurement.

[0158] [Table 2] Table 2: Dye modification in the blue region of color filters and backlight units Treat ID:Treat ID;Dye:Dye;Dye absorption peak, nm:Dye absorption peak, nm;Toxicity factor:Toxicity factor;Change %:Change %;Toxicity Blue Ratio:Blue light toxicity ratio;Change %;Luminance:Luminance;Adobe RCB Coverage:Adobe RGB Coverage;Change %;DCI-P3 Coverage:DCI-P3 Coverage;Change %;sRGB Coverage:sRGB Coverage;Change %;BT.2020 Coverage:BT.2020 Coverage;Change %;Change %;NTSC Coverage:NTSC Coverage;Change %;Change %

[0159] In the first example, the selected dye absorbs in the toxic blue range with a maximum absorption centered around 430 nm (see Table 2, absorption peak between 420 and 435), but may also show a second absorption peak in a second color range (e.g., green or red) (see Table 2, second peak between 525 and 560). In some cases, a single dye can be applied to the color filter or backlight unit, while in other cases, two or more dyes may be combined and applied together to the color filter or backlight unit in order to increase the absorption of toxic blue light and lower the blue phototoxicity ratio. When these dyes are applied to the color filter, the blue phototoxicity factor can be reduced by up to about 20%, which is an improvement compared to the same modification in the backlight unit.

[0160] As shown in Table 2, modifications at the color filter ("CF") level result in a more significant reduction in blue phototoxicity than modifications at the backlight unit (BLU) level. Additionally, the luminance loss of the display is less significant with modified color filters than with modified BLUs, and overall, the changes introduced by the dyes on the color filters result in improved color gamut, as evidenced by measurements of each standard color gamut system included in Table 2. More specifically, when the disclosed dyes are applied to color filters, the percentage coverage of the color gamut generally increases (i.e., there is a positive rate of change).

[0161] In some embodiments, light conversion materials (filters) placed at various locations within the backlight unit have been shown to amplify absorption by up to 10-12 times, which greatly increases the efficiency of selective light conversion or light absorbing materials that can filter, for example, blue light or toxic blue light.

[0162] The graph in FIG. 2 is for the transmittance spectrum of a color filter with blue dye modification. In FIG. 2, the blue spectrum before dye modification is represented by dots with "X"s, and the solid black curve represents the blue spectrum of the color filter with blue dye modification. The graph shows that the blue dye modification reduces the wave height (representing transmittance) and absorbs toxic blue light, as seen at wavelengths around 430 nm. The effectiveness of the dye range varies depending on the type of display, the amount of dye, and the combination of dyes (if any). In the embodiment of FIG. 2, the blue subpixel transmits in the range of 350-530 nm and has multiple peaks within this range. The green subpixel transmits in the range of 460-630 nm and has multiple peaks within this range. The red subpixel transmits in the range above 570 nm and has multiple peaks within this range. This creates an opportunity to amplify the effect of selective light conversion or light absorbing materials that block blue or toxic blue light, or other films or layers that can modify the spectrum. These selective light converting or light absorbing materials can be included as separate films or can be coated onto or added within any of the layers that make up the disclosed backlight units.

[0163] Figure 2 shows three effective transmittance curves for three different subpixels of a color filter. In Figure 2, one curve is the absorption curve of a blue dye added to the blue subpixel of the color filter of Figure 1. The second absorption curve is the measured transmittance of a green subpixel of the same color filter. The third absorption curve is the transmittance of a red subpixel of the same color filter. All three curves have peaks adjacent to each other and represent the light absorption of the backlight unit for all three subpixels, but in different ranges associated with wavelengths of light of a particular color.

[0164] As shown in FIG. 2, in some embodiments, adding blue dye to a color filter may change the appearance of the transmittance spectrum of the display. More specifically, FIG. 20 shows that applying an additive blue dye to a color filter (e.g., at the level of the blue subpixel) may reduce the light emitted in the toxic blue range of about 430 nm (+ / - 30 nm). The transmittance graph may represent the overall effect on light of a color filter with and without blue dye. The blue dye curve from 428-500 nm shows that the impact of blue light on radiance may be less than the shape of the original curve without the blue dye. Specifically, when modifying the dye at the color filter level (line labeled "Blue & dyes"), the resulting blue peak emission (from the measured white light emission of the display after dye modification) may be narrower than the blue peak emission of the original display (from the measured white light emission of the display before dye modification) (line labeled "Blue"), and may shift toward longer blue wavelengths.

[0165] FIG. 3 further illustrates the spectrum and measurements of light (Spectral Power Distribution (SPD)) when blue dye is added to the color filters. The light of the display can be measured with a radiometer, and the intensity measurements are shown on the Y-axis. In FIG. 3, the wavelength of light from the display is shown on the X-axis. In some cases, the type of display can affect the resulting X-axis and Y-axis values. Applying blue dye at the level of the color filters can result in a blue light peak between 380-500 nm, a green light peak between 500-600 nm, a red light peak between 600-660 nm, and combinations thereof. The graph in FIG. 3 illustrates one embodiment of the inherent spectrum when blue dye is added to the color filters of a display system.

[0166] Figure 3 shows the Spectral Power Distribution (SPD) of a display with blue dye modification on the color filters. More specifically, Figure 3 shows the effective transmittance of a light conversion or light absorbing material (blue light filtering layer) across the visible spectrum as a function of where the light conversion or light absorbing material is located within the display (in this case the color filters). The effective transmittance is calculated by dividing the emission from the display with the light conversion or light absorbing material by the emission of the display without the light conversion or light absorbing material. The various spectra shown in Figure 3 show the effect of the light conversion or light absorbing material layer when placed at various locations (positions) within the display (outside and inside the color filters). Figure 3 includes the amplitude associated with absorption on the X-axis and the wavelength values ​​shown on the Y-axis.

[0167] FIG. 4 shows the SPD of a display with blue dye modification at the BLU level. More specifically, FIG. 4 shows the effective transmittance of a light converting or absorbing material (blue light filtering layer) across the visible spectrum as a function of the location of the light converting or absorbing material in the display (in this case the BLU). The light of the display can be measured with a radiometer. The absorption measurements can be recorded on the Y-axis. In FIG. 4, the wavelength of light from the display is recorded on the X-axis. In some cases, the type of display can affect the resulting X-axis and Y-axis values. When the blue dye is applied at the BLU level, a blue light peak can occur between 430-470 nm, a green light peak between 490-580 nm, a red light peak between 600-660 nm, and combinations thereof. The graph in FIG. 4 shows the transmittance of the blue light or absorbing material. FIG. 4 shows one embodiment of a unique spectrum with blue dye added to the BLU of a display system.

[0168] In some embodiments, the dye applied at the color filter level (or in some cases at the backlight unit) can have at least two absorption peaks, namely a main absorption peak in the blue light range and a secondary absorption peak that can exceed 500 nm. Because this secondary absorption peak exceeds 500 nm, the leakage of green light (i.e., light with longer wavelengths) into the blue subpixels can be reduced, the blue emission spectrum can be narrowed, and the blue Y-axis coordinate / value in the color gamut can be moved to a lower value. The harmful blue light from the main peak can be filtered, the Y-axis coordinate / value can be increased, the blue emission peak can be narrowed, the saturation can be increased, and the blue X-axis coordinate / value can be advantageously moved to the left. Other pigments or other absorbers with wavelengths above 495 nm (+ / - 15 nm) can be used to reduce the leakage of longer wavelength light into the blue subpixels.

[0169] As mentioned above (as shown in Table 2), adding a second dye to the first dye in either the color filter or BLU brings more significant difference in the reduction of blue phototoxicity coefficient, difference in luminance loss, and difference in color gamut area. Therefore, it can be seen that the modification of the color filter leads to a better overall performance of the display.

[0170] In another embodiment (see Table 3 below), the color filters and / or BLUs can be modified with dyes that absorb in the green range between 490nm and 610nm. Modification of the green range does not significantly affect the blue emission, but the brightness and color gamut can be affected by the modification. Table 3 is one embodiment of values ​​measured on one type of display. Measured values ​​will vary for different types of monitors.

[0171] [Table 3] Table 3: Dye modifications in the green range for color filters and backlight units Dye:Dye;Dye absorption peak, nm:Dye absorption peak, nm;Toxicity factor:Toxicity factor;Change %:Change %;Toxicity Blue Ratio:Blue light toxicity ratio;Change %;Luminance:Luminance;Adobe RCB Coverage:Adobe RGB coverage;Change %;DCI-P3 Coverage:DCI-P3 coverage;Change %;sRGB Coverage:sRGB coverage;Change %;BT.2020 Coverage:BT.2020 coverage;Change %;Change %;NTSC Coverage:NTSC coverage;Change %;Change %

[0172] In some embodiments, a green dye that absorbs below 500 nm is used. In other embodiments, a green dye that absorbs above 575 nm is used. Using a dye that absorbs below 500 nm in the green filter reduces leakage of short wavelength light into the green subpixels, while using a dye that absorbs above 575 nm in the green filter reduces leakage of long wavelength light into the green subpixels.

[0173] Short wavelength light leaking into the green subpixel can desaturate the green primary color, negatively shifting its Y-axis coordinate / value, and potentially unfavorably shifting its X-axis coordinate / value, depending on the target gamut value. Alternatively, or in addition to dyes, other pigments or other absorbers with wavelengths below 500 nm can be used to reduce leakage of short wavelength light into the green subpixel and improve the saturation of the green subpixel.

[0174] Similar to short-wavelength light, leakage of long-wavelength light into the green subpixel can desaturate the green primary color, shifting its Y-axis value or coordinate in a negative direction, and may also unfavorably shift its X-axis coordinate / value, depending on the target gamut value. Other pigments or other absorbers with wavelengths above 590 nm can be used instead of or in addition to dyes to reduce leakage of long-wavelength light into the green subpixel.

[0175] The graph in FIG. 5 is for the transmittance spectrum of a color filter with green dye modification. In FIG. 5, the green spectrum before dye modification is represented by the dots with "crosshairs" and the curve of white dots represents the green spectrum of the color filter with green dye modification. The graph shows that the green dye modification reduces the wave height. The green dye modification range can occur in the range of 470-620 nm. The effectiveness of the dye range varies based on the type of display, the amount of dye, and the combination of dyes (if any). In the embodiment of FIG. 5, the blue subpixel transmits in the range of 350-530 nm and can have multiple peaks in this range. The green subpixel transmits in the range of 460-630 nm and can have multiple peaks in this range. The red subpixel transmits in the range of 570 nm and above and can have multiple peaks in this range. This creates an opportunity to amplify the impact of selective light conversion materials or light absorbing materials. For example, leakage into the subpixels can be reduced, improving brightness and color gamut. These selective light converting or light absorbing materials can be included as separate films or can be coated onto or added within any of the layers that make up the disclosed backlight units.

[0176] In some embodiments, adding a green dye to a color filter can change aspects of the transmittance spectrum of a display, as shown in Figure 5. More specifically, Figure 5 shows that applying an added green dye to a color filter (e.g., at the level of the green subpixel) can reduce the light emitted in the green range of 510nm to 580nm (+ / -30nm). A transmittance graph can represent the overall effect of the color filter on light with and without the green dye.

[0177] FIG. 6 shows the SPD of a display with green dye added to the color filters. The light of the display can be measured with a radiometer, and as previously described, the intensity measurements are shown on the Y-axis. In FIG. 6, as previously described, the wavelength of the light from the display is shown on the X-axis. The graph shows that the model spectrum resembles the measured light values. The central peak is in the range of 510-560 nm. There is a slight drop or absorption near 540 nm, where the spectral model is slightly less than the actual measurement (higher absorption). Similarly, the spectral model is slightly less near 580-605 nm. If green dye is applied at the level of the color filters, there may be a blue light peak between 430-470 nm, a green light peak between 490-580 nm, a red light peak between 600-660 nm, and combinations thereof. The graph in FIG. 6 shows that the model spectrum resembles the measured light values. FIG. 6 shows one embodiment of a unique spectrum with green dye added to the color filters of a display system.

[0178] FIG. 7 shows the SPD of a display with green dye modification at the BLU level. Similar to FIG. 6, FIG. 7 shows a graphical representation of predicted values ​​measured after modeling the actual light and measured light. More specifically, FIG. 7 shows the effective transmittance across the visible spectrum of a light converting or absorbing material (green light filtering layer) as a function of where the light converting or absorbing material is located within the display (in this case the BLU). The light of the display can be measured with a radiometer. The absorption measurements can be recorded on the Y-axis. In FIG. 7, the wavelength of light from the display is recorded on the X-axis. In some cases, the type of display can affect the resulting X-axis and Y-axis values. When the green dye is applied at the BLU level, the blue light peaks between 420-470 nm, the green light peaks between 490-590 nm, the red light peaks between 600-660 nm, and combinations of these may exist. The graph in FIG. 7 shows one embodiment of a unique spectrum with green dye added to the BLU of a display system.

[0179] In another embodiment (see Table 4 below), the color filter and / or BLU can be modified with a dye that absorbs in the red range below 590 nm. Modification of the red range at the color filter level can reduce the leakage of short wavelength light into the red subpixel. This leakage desaturates the red primary color. Therefore, using a red dye in the red subpixel also helps manage the x,y coordinates (axes) for optimal color gamut coverage. Table 4 shows how various measurements such as brightness and color gamut change when a red dye is added to one type of display. There are different types of monitors that show different values ​​when measured.

[0180] [Table 4] Table 4: Dye modification in the red region of color filters and backlight units Dye:Dye;Dye absorption peak, nm:Dye absorption peak, nm;Toxicity factor:Toxicity factor;Change %:Change %;Toxicity Blue Ratio:Blue light toxicity ratio;Change %;Luminance:Luminance;Adobe RCB Coverage:Adobe RGB coverage;Change %;DCI-P3 Coverage:DCI-P3 coverage;Change %;sRGB Coverage:sRGB coverage;Change %;BT.2020 Coverage:BT.2020 coverage;Change %;Change %;NTSC Coverage:NTSC coverage;Change %;Change %

[0181] The values ​​listed show the result of adding a red dye to the red subpixel in terms of its effect on the toxic-blue ratio, toxicity coefficient, luminance, and change in gamut. As with the green subpixel, leakage of short-wavelength light into the red subpixel can desaturate the red primary color, negatively moving the Y-axis coordinate / value. It can also adversely shift the X-axis coordinate / value, depending on the target gamut value. Other pigments or other absorbers with wavelengths below 600 nm can be used instead of or in addition to the dye to reduce leakage of short-wavelength light into the red subpixel and improve the saturation of the red subpixel.

[0182] The graph in FIG. 8 is of the transmittance spectrum of a color filter with red dye modification. The graph illustrates one non-limiting embodiment where red, blue, and green dyes are added to a color filter. In FIG. 8, the red spectrum before dye modification is represented as a curve made up of dots with a "right slash" and the curve made up of dots with a left slash represents the red spectrum from the color filter (or, more specifically, the red subpixel) with red dye modification. The modification of the color filter with a red dye suggests that red light is absorbed at wavelengths above 580 nm.

[0183] In some embodiments, the added dyes may affect the graph by narrowing and reducing the crossover of green and red. The separation between colors may be improved, improving color gamut. The modified range of the red dye may occur within the range of 560-750 nm. The effectiveness of the dye range will vary based on the type of display, the amount of dye, and the combination of dyes (if any). In the embodiment of FIG. 8, the blue subpixel transmits in the range of 380-530 nm and may have one or more peaks within this range. The green subpixel transmits in the range of 460-63 nm and may have one or more peaks within this range. The red subpixel transmits in the range of 560 nm and above and may have one or more peaks within this range. This may create an opportunity to amplify the impact of selective light conversion or light absorbing materials. For example, leakage into the subpixels may be reduced, improving brightness and color gamut. These selective light conversion or light absorbing materials may be included as separate films or may be coated on or added within any of the layers that make up the disclosed backlight units.

[0184] In some embodiments, adding a red dye to the color filters can shift aspects of the transmittance spectrum of the display, as shown in Figure 8. More specifically, Figure 8 shows that applying a red dye to a color filter (e.g., at the level of the red subpixel) can result in a shift in the light emitted in the red range. More specifically, the lower end of the red range without the red dye can start between 560nm-570nm, whereas the lower end of the red range with the red dye can start between 570nm-580nm (+ / -30nm). The transmittance graph represents the overall effect of the color filters on the light with and without the red dye.

[0185] FIG. 9 shows the SPD of a display when a red dye is added to the color filters. The light of the display can be measured with a radiometer, and as previously described, the intensity measurements are shown on the Y-axis. In FIG. 9, as previously described, the wavelength of the light from the display is shown on the X-axis. The graph shows that the model spectrum resembles the measured light values. The modification with the red dye begins at about 580 nm. The graph shows one embodiment of the original color filter and the values ​​after modification of the color filter with the red dye. As a result, there may be multiple peaks in the red dye values. For example, there may be a first peak between 600 nm and 620 nm and a second peak between 625 nm and 645 nm. In the embodiment of FIG. 9, the absorption range appears to be down at 670 nm. If the red dye is applied at the color filter level, there may be a blue peak between 420-475 nm, a green peak between 490-580 nm, a red peak between 600-620 nm, an alternative or additional red peak between 625-645 nm, and combinations thereof. The graph in Figure 9 shows one embodiment of a unique spectrum with the red dye added to the color filters of a display system.

[0186] Figure 10 shows the SPD of a display with red dye absorption at the BLU level. Similar to Figure 9, Figure 10 shows a graphical representation of the predicted values ​​measured after modeling the actual light and the measured light. More specifically, Figure 10 shows the effective transmittance across the visible spectrum of a light converting or light absorbing material (red light filtering layer) as a function of where the light converting or light absorbing material is located within the display (in this case the BLU). The light of the display can be measured with a radiometer. The absorption measurements can be recorded on the Y-axis. In Figure 10, the wavelength of light from the display is recorded on the X-axis. In some cases, the type of display can affect the resulting X-axis and Y-axis values. When red dye is applied at the BLU level, there may be a blue light peak at approximately 430-470 nm, a green light peak between 490-580 nm, a red light peak between 600-620 nm, a red light peak between 625-645 nm, and combinations thereof. Some ranges have multiple peaks within the range. In some embodiments, there may also be a decrease in transmission or absorption, such as a modification in the green range of 515-580 nm and a modification in the red range of 580-620 nm. The graph in Figure 10 shows one embodiment of a unique spectrum where a red dye is added to the BLU of the display system.

[0187] In another embodiment (see Table 5 below), combinations of dyes can be used to modify the color filters, the backlight units, or both simultaneously. Measurements of blue phototoxicity factor, luminance, and color gamut coverage show that modification of blue absorbing dyes at the color filter level (e.g., blue subpixels) is favorable for reducing toxicity factors. It also results in lower luminance loss when compared to modification of BLUs only, or when compared to modification of both color filters and BLUs. Different combinations of dyes can also be used to customize the final color performance of the display. For example, short and long wavelength light leakage into the subpixels can be reduced. Table 5 shows how different measurements, including but not limited to luminance and color gamut, change when multiple dyes are added to the color filters and / or BLUs in one type of display. There are different types of monitors that have different values ​​when measured.

[0188] [Table 5] Table 5: Dye modifications in the blue and green range for color filters and backlight units Dye:Dye;Dye absorption peak, nm:Dye absorption peak, nm;Toxicity factor:Toxicity factor;Change %:Change %;Toxicity Blue Ratio:Blue light toxicity ratio;Change %;Luminance:Luminance;Adobe RCB Coverage:Adobe RGB coverage;Change %;DCI-P3 Coverage:DCI-P3 coverage;Change %;sRGB Coverage:sRGB coverage;Change %;BT.2020 Coverage:BT.2020 coverage;Change %;Change %;NTSC Coverage:NTSC coverage;Change %;Change %

[0189] [Table 6] Table 6: Dye absorption peaks (nm) related to Table 5 Dyes: Dye;Dye absorption peak (nm): Dye absorption peak (nm)

[0190] In some cases, there are multiple dye absorption peaks (nm) depending on the dye used. Overall, dye modification at the BLU level can affect all primaries, potentially affecting light in the green range and, to a lesser extent, the blue range, resulting in reduced luminance. This potential emission reduction correlates closely with the photopic sensitivity curve, resulting in a greater reduction in luminance. However, dye modification at the color filter level can only affect one primary at a time, allowing for better optimization of the color emission of each primary and customization of the SPD of the resulting display. Table 6 shows some values ​​for dye modification in both the blue and green ranges for color filters and backlight units using various dye combinations.

[0191] Figure 11 represents the transmittance spectrum of the color filters after both blue and green dye modification. The graph shows the effect of dye modification on the overall luminance in the color filters. In Figure 11, data points related to the transmittance curves of the blue, green, and red subpixels before the addition of dyes are indicated by "x", "crosshair", and "right slash", respectively, while data points related to the transmittance curves of the blue, green, and red subpixels after the addition of dyes are indicated by solid black lines, solid white lines, and "left slash", respectively. The peaks of the dye-modified color filters occur at approximately 440-490 nm, 500-80 nm, and 600-680 nm (+ / - 30 nm) in the display measurements. The peaks of the color filters before dye modification occur at approximately 400-480 nm, 500-590 nm, and 600-680 nm (+ / - 30 nm) in the display measurements. In some embodiments, the added dyes can affect the graph by narrowing and reducing blue-green and green-red crossovers, thus improving the separation between subpixel transmittances and therefore reducing leakage into the subpixels and improving brightness and color gamut. The effectiveness of the dye range varies depending on the type of display and the amount of dye and combination of dyes, if any. The selective light conversion or light absorbing materials can be included as a separate film or can be coated on or added within any of the layers that make up the disclosed backlight units.

[0192] FIG. 12 shows the SPD of a display when both blue and green dyes are added to the color filters. The light of the display can be measured with a radiometer and the intensity measurements are shown on the Y-axis as previously described. In FIG. 12, the wavelength of the light from the display is shown on the X-axis as previously described. The graph shows one embodiment of the original color filter and the resulting values ​​after modifying the color filter with blue and green dyes. The dye modification (i.e., adding blue and green dyes to the color filter) results in a blue light absorption peak between 430 nm and 470 nm, a green light absorption peak between 484 nm and 588 nm, a red light absorption peak between 600 nm and 620 nm, an alternative or additional red light absorption peak between 625 nm and 645 nm, and combinations thereof. The solid lines show the measured modified color filter absorption values.

[0193] Figure 13 shows the SPD of a display with blue and green dye absorption at the BLU level. Similar to Figure 12, Figure 13 shows a graphical representation of the predicted values ​​measured after modeling the actual light and the measured light. More specifically, Figure 13 shows the effective transmittance of a light converting or absorbing material across the visible spectrum as a function of where the light converting or absorbing material is located within the display (in this case the BLU). The light of the display can be measured with a radiometer. The measured absorption can be recorded on the Y-axis. In Figure 13, the wavelength of light from the display is recorded on the X-axis. In some cases, the type of display can affect the resulting X-axis and Y-axis values. After adding both blue and green dyes to its color filters, the difference between the measured and actual values ​​becomes larger. When blue and green dyes are applied at the BLU level, the blue light absorption peak is near 450 (+ / - 15 nm), the green light peak is at 500-510 nm and 540-560 nm (+ / - 15 nm), the red light peak is at 610-620 nm and 630-640 nm (+ / - 5 nm), and combinations of these exist. As shown, some ranges have multiple peaks within the range. The graph in Figure 13 shows one embodiment of a unique spectrum with blue and green dyes added to the BLU of a display system.

[0194] Embodiments further demonstrate that display systems can reduce blue light toxicity while increasing brightness and expanding or shifting the color gamut. The examples described so far have primarily demonstrated how including certain dyes in the color filters is an improvement over including them in a layer within the backlight unit. The comparisons show some improvement in color gamut over the original display performance, with the primary comparison being with dyes in the backlight unit. The resins here can be cured thermally or photolithographically, although most color filter materials are cured photolithographically (due to the very narrow dimensions of modern displays).

[0195] Figures 14-25 show the brightness, toxic blue light, and color gamut data for various color filter modifications. One common way manufacturers increase the transmittance or brightness of color filters is to reduce the coating thickness, shortening the light path and reducing absorption through lower dye coverage per square area. The figures shown here show, with various representative lines, the corresponding color filter ("CF") transmittance / brightness increase for various wavelengths associated with a particular color, mathematically simulating a thinner coating. In some cases, the color filter thickness can be reduced to improve brightness, while the color performance can be maintained or even improved by adding dyes or pigments at the color filter level. The spectra for blue, green, and red dyes or pigments added to the color filters are shown in their respective (separate) graphs. These individual graphs (see, for example, Figures 15a-15c, Figures 19a-19c, and Figures 23a-23c) show that the transmission peaks increase while the overall width decreases, thereby enhancing color clarity by reducing low / high wavelength leakage into each subpixel. The selective filtering of toxic blue light is shown by the decrease in transmission especially between 415-435 nm in Figures 15a, 19a, and 23a. The maintained or improved color gamut is most clearly shown in the comparison of color changes shown in Figures 17a-17c, Figures 21a-21c, and Figures 25a-25c, and in the color gamut charts in Figures 17d, 21d, and 25d. Figures 17d, 21d, and 25d show the different display spectra over color separation and color gamut.

[0196] Figure 14a (without dye) and Figure 14b (color filter with dye) show the change in transmittance before and after including dye in the color filter. Comparing Figure 14a and Figure 14b, adding dye clearly improves the separation between different transmittance peaks. For example, there is overlap between the blue and green transmittance curves in Figure 14a, which is significantly reduced in Figure 14b. Comparing the overlap between the green and red curves, the overlap is similar, but less pronounced. This reduction in overlap improves the color gamut. Furthermore, as can be seen from the comparison of Figure 14a and Figure 14b, adding dye does not affect the overall transmittance of each color. In fact, the green and red transmittance curves show a significant improvement in transmittance. Therefore, as shown in the figure, the color gamut is improved without any reduction in transmittance or brightness.

[0197] Figures 15a-15c compare the individual color filters of graphs 14a and 14b. The color filters are associated with specific wavelength ranges, and the isolated color filters show the changes between the unmodified and dye-modified color filters. Specifically, Figure 15a compares the transmission curve of the original blue filter with the transmission curve of the modified blue filter. Similarly, Figure 15b compares the transmission curve of the original red filter with the transmission curve of the modified red filter, and Figure 15c compares the transmission curve of the original green filter with the transmission curve of the modified green filter. The maintenance and / or improvement of the transmission after the addition of the dye is clearly shown in Figures 15a-15c by comparing the peaks of each graph for the unmodified and modified filters.

[0198] Figures 16a-16b show the effect of adding dyes to the color filters on the saturation of the red, green, and blue primary colors. More specifically, Figures 16a-16b are graphs of the color gamut that is maintained (or improved), as can also be seen in the color gamut chart in Figure 17d. These figures show that adding dyes to the color filters brightens the primary colors. Figures 16a (without dyes) and 16b (color filters with dyes) show the change in color after adding dyes to the color filters. As with the previous Figures 14-15, Figures 16a and 16b are broken down by color in Figures 17a-17c, and it is clear that adding dyes to the color filters maintains (but does not improve) the color saturation and clarity. Figure 17d shows the color gamut charts of the original (no dyes added) and modified (dyes added to the color filters) display panels. As is well known, the color gamut chart shows the three primary colors: red, green, and blue. Although the diagrams shown here are in black and white, they are interpreted as incorporating the color gradations of a standard color gamut chart, as shown in the following figure. https: / / upload.wikimedia.org / wikipedia / commons / 9 / 91 / SRGB_chromaticity_CIE1931.svg

[0199] [Table 7] Table 7: Breakdown of the data presented in Figure 17d.

[0200] Thus, Figures 14-17 show that, overall, adding dyes to color filters (e.g., at the subpixel level as shown above, one can add blue dye to blue subpixels, green dye to green subpixels, red dye to red subpixels, and combinations thereof) can lead to an overall increase in brightness, a reduction in toxic blue light, and a maintenance or improvement in color gamut. More specifically, it can reduce the blue phototoxicity factor by 7.6% and increase brightness by 9.3%. As shown in Table 8 below, the color gamut coverage percentage is most relevant to show the improvement in various standard color gamut charts (NTSC, sRGB, etc.). Some of the standards measured (see NTSC and Adobe RGB) show effective maintenance of the color gamut, while others show increases in the range of 2-3%. Thus, adding dyes to color filters can clearly increase brightness while at least maintaining the color gamut.

[0201] [Table 8] Table 8: Color gamut measurement of dye-containing color filters CIE 1931 Color Gamut: CIE 1931 color gamut; Original panel: Original panel; Modified panel: Modified panel; Ratio %: Ratio %; Coverage %: Coverage %

[0202] Figures 18-21 show the same type of information as Figures 14-17, but with pigments rather than dyes used for the color filters. As shown, pigment dispersions perform better than standard color filters. However, pigments are not optimized for the photolithography required for modern displays. Therefore, while described and potentially usable, the preferred embodiment of the disclosed system uses dyes. Baseline performance shows that pigments alone can reduce toxicity factors by almost 10% and also provide improved color gamut coverage.

[0203] Figure 18a (without pigment) and Figure 18b (color filter with pigment) show the change in transmittance before and after the pigment is included in the color filter. Comparing Figure 18a and Figure 18b, the addition of pigment clearly improves the separation between different transmittance peaks. For example, there is an overlap between the blue and green transmittance curves in Figure 18a, but the overlap is reduced in Figure 18b. The same is true, and even more pronounced, when comparing the overlap of the green and red curves. As mentioned above, this reduction in overlap improves the color gamut. Furthermore, as can be seen from the comparison of Figure 18a and Figure 18b, the overall transmittance of each color is not affected by the addition of pigment. In fact, the transmittance is significantly improved in the green and red transmittance curves. Therefore, as shown in the figure, the improvement in the color gamut does not result in a decrease in transmittance or brightness.

[0204] Figures 19a-19c compare the individual color filters of graphs 18a and 18b. The color filters are associated with specific wavelength ranges, and the isolated color filters show the changes between the unmodified and pigment-modified color filters. Specifically, Figure 19a compares the transmission curve of the original blue filter with the transmission curve of the modified blue filter. Similarly, Figure 19b compares the transmission curve of the original red filter with the transmission curve of the modified red filter, and Figure 19c compares the transmission curve of the original green filter with the transmission curve of the modified green filter. The enhancement in transmission after adding pigment is clearly shown in Figures 19a-19c by comparing the peaks of each graph for the unmodified and modified filters.

[0205] Figures 20a-20b show the effect of adding pigments to the color filters on the saturation of the red, green, and blue primary colors. More specifically, Figures 20a-20b are graphs of the color gamut that is maintained (or improved), as can also be seen in the color gamut chart in Figure 21d. These figures show that adding pigments to the color filters brightens the primary colors. (Color filters with pigments) shows the change in color after adding pigments to the color filters. As in the previous Figures 18-19, Figures 20a and 20b are categorized by color in Figures 21a-21c, and it is clear that adding pigments to the color filters maintains (but does not improve) the color saturation and clarity. Figure 21d shows the color gamut charts of the original (no pigments added) and modified (pigments added to the color filters) display panels. As is well known, the color gamut chart shows the three primary colors: red, green, and blue. Although the diagram shown here is in black and white, it is interpreted as incorporating the color gradations of a standard color gamut chart, as shown in the following figure. https: / / upload.wikimedia.org / wikipedia / commons / 9 / 91 / SRGB_chromaticity_CIE1931.svg

[0206] [Table 9] Table 9: Breakdown of the data presented in Figure 21d.

[0207] Thus, Figures 18-21 show that, overall, adding pigments to color filters (e.g., at the subpixel level mentioned above, blue dyes and / or pigments can be added to blue subpixels, green dyes and / or pigments can be added to green subpixels, red dyes and / or pigments can be added to red subpixels, and combinations thereof) can lead to an overall increase in brightness, a reduction in toxic blue light, and a maintenance or improvement in color gamut. More specifically, it can reduce the blue phototoxicity factor by 9.79% and increase brightness by 1.0%. As shown in Table 10 below, color gamut coverage percentages are most relevant to show improvements in various standard color gamut charts (NTSC, sRGB, etc.). All standards measured show increases ranging from 6% to 21%. Thus, adding pigments to color filters can significantly improve color gamut while effectively maintaining brightness.

[0208] [Table 10] Table 10: Gamut measurements for pigmented color filters CIE 1931 Color Gamut: CIE 1931 color gamut; Original panel: Original panel; Modified panel: Modified panel; Ratio %: Ratio %; Coverage %: Coverage %

[0209] Figures 22-25 show the same type of information as Figures 14-17 and 18-21, but instead of either dyes or pigments being present in the color filters, both dyes and pigments are used. Thus, in the figures, Figure 22a (no dyes / pigments) and Figure 22b (color filters with dyes and pigments) show the change in transmittance before and after the dyes and pigments are included in the color filters. Comparing Figures 22a and 22, the addition of dyes / pigments clearly improves the separation between the different transmittance peaks. For example, there is an overlap between the blue and green transmittance curves in Figure 22a, which is clearly reduced in Figure 22b. This is also true and even more pronounced when comparing the overlap of the green and red curves. As mentioned before, this reduction in overlap improves the brightness and color gamut. Furthermore, as can be seen from the comparison of Figures 22a and 22b, the overall transmittance of each color is not affected by the addition of dyes or pigments. In fact, the green and red transmittance curves show a significant improvement in transmittance. Therefore, as shown in the figure, even though the color gamut is improved, there is no decrease in transmittance or brightness.

[0210] Figures 23a-23c compare the individual color filters of Figures 22a and 22b. The color filters are associated with specific wavelength ranges, and the isolated color filters show the changes between the unmodified and dye / pigment modified color filters. Specifically, Figure 23a compares the transmission curve of the original blue filter with the modified blue filter. Similarly, Figure 23b compares the transmission curve of the original red filter with the modified red filter, and Figure 23c compares the transmission curve of the original green filter with the modified green filter. The enhancement in transmission after the addition of dyes and pigments is clearly shown in Figures 23a-23c by comparing the peaks of each graph for the unmodified and modified filters.

[0211] Figures 24a-24b show the effect of adding dyes and pigments to the color filters on the saturation of the red, green, and blue primary colors. More specifically, Figures 24a-24b are graphs of the maintained (or improved) color gamut, as seen in the color gamut chart in Figure 25d. These figures show that adding dyes and pigments to the color filters brightens the primary colors. Figure 24a (no dyes / pigments) and Figure 24b (color filters with dyes and pigments) show the change in color after adding dyes and pigments to the color filters. As with Figures 22-23 above, Figures 24a and 24b are categorized by color in Figures 22-23. It is clear in Figures 25a-25c that the saturation and clarity of the colors are maintained or improved by adding dyes and pigments to the color filters. Figure 25d shows the color gamut chart of the original display panel (no dye / pigment added) and the modified display panel (dye and pigment added to the color filter). As is well known, the color gamut chart shows three primary colors: red, green, and blue. Although the diagram shown here is in black and white, it is interpreted as incorporating the color gradation of the standard color gamut chart, as shown in the following figure. https: / / upload.wikimedia.org / wikipedia / commons / 9 / 91 / SRGB_chromaticity_CIE1931.svg

[0212] [Table 11] Table 11: Breakdown of the data shown in Figure 25d.

[0213] Thus, overall, Figures 22-25 show that the addition of dyes and pigments to color filters (e.g., at the subpixel level described above, blue dyes and / or pigments can be added to blue subpixels, green dyes and / or pigments can be added to green subpixels, red dyes and / or pigments can be added to red subpixels, and combinations thereof) can result in increased overall brightness, reduced toxic blue light, and maintained or improved color gamut.

[0214] Specifically, it can reduce the blue phototoxicity factor by 7.41% and improve brightness by 3.7%. As shown in Table 12 below, the color gamut coverage percentage is most relevant in showing the improvement for the various standard color gamut charts (NTSC, sRGB, etc.). All standards measured show improvements ranging from 6-13%. Thus, the addition of dyes and pigments to the color filters clearly improves brightness and significantly improves color gamut.

[0215] [Table 12] Table 12: Gamut measurements for dye and pigment color filters CIE 1931 Color Gamut: CIE 1931 color gamut; Original panel: Original panel; Modified panel: Modified panel; Ratio %: Ratio %; Coverage %: Coverage %

[0216] Other features may be added to optimize the stack. Display systems according to the present disclosure may include backlight units that include optical stacks. The disclosed optical stacks may include light emitting systems such as light emitting diodes, arrays of light emitting diodes, or other sources of substantially white light. These optical stacks may include layers of optical films that can transmit light or modify the properties of the light passing through them. This includes reflective layers, diffusing layers, brightness enhancing layers (usually prisms), and polarizing filters. In some embodiments, the optical stacks may include at least one optical film with at least one light conversion layer therein. Additionally, the same at least one optical film may include a light absorbing layer thereon or therein. Alternatively, the optical stacks may include at least one optical film with at least one light conversion material therein and at least one optical film with at least one light absorbing material disposed thereon or therein. The stacks may also reduce glare, providing additional benefits to the appearance of the resulting display.

[0217] In other embodiments, depending on the dyes or pigments used and the amounts used in the layers of color filters, the resulting color seen by the user is changed by modifying the color gamut of the emitted light passing through the filter layers. Adding certain compounds, such as dyes or pigments, in certain amounts, changes the color of the resulting light passing through the color filters within the color gamut. In other embodiments, the additional compounds also result in a decrease in the transmittance and emissivity values ​​of the color filters, decreasing the color values ​​that represent the emission, transmittance, intensity, etc. of the colors. The decrease in color values ​​reduces color overlap and improves the clarity between colors, allowing for better color control and image clarity.

[0218] The color filters may also include dyes that affect the particular color of the associated subpixel in some embodiments. For example, a dye may be added to a blue subpixel because the selected dye or pigment affects the color blue. In some cases, the dye absorbs blue light, while in other cases, the dye increases or improves the transmission of blue wavelengths. In some embodiments, the dye affects other wavelengths besides blue light, while in other embodiments, the light increases or improves the transmission of blue light wavelengths (particularly light of a particular wavelength that the user associates with blue light). In other embodiments, the same or different dyes, pigments, or compounds may be added to other colored subpixels (not limited to red and green subpixels) to further control color, color contrast, and image sharpness, and to reduce toxicity of particular light in particular wavelength ranges. Adding red and green dyes, compounds, pigments, etc. to the red and green subpixels, respectively, shifts the color gamut and modifies the light filtered to improve the resulting display of the light. In this case, the expanded color gamut or modified color definition area improves the user's adverse effects and enhances the resulting emission. Improved display images and safer light emission reduce adverse effects on users, improving their health and well-being.

[0219] Methods of mitigating blue light emissions based on absorbing (or eliminating) light, without subsequent emission of light in the visible region of the electromagnetic spectrum, generally result in a decrease in the brightness (measured and / or perceived) of the display compared to an otherwise identical reference display lacking such absorption characteristics. In some cases, the power input to the display may be increased (compared to the power input to a reference display) to compensate for the decrease in brightness associated with such absorption. In general, increasing the power consumption of the display may be undesirable and may adversely affect battery life, especially in portable devices.

[0220] In this disclosure, a system for modifying the emission of light from a display is disclosed in which a light converting or light absorbing material can be used at a location remote from the display's light source (such as color filter 112 in FIG. 1). A light converting material can generally absorb light in a first wavelength range and emit light in a second wavelength range (thus "converting" light from one wavelength range to another). A light absorbing material absorbs light in one wavelength range. In this disclosure, conversion from a shorter wavelength to a longer wavelength can be referred to as "up-conversion" and conversion from a longer wavelength to a shorter wavelength can be referred to as "down-conversion". However, these definitions may not be universal and other documents may define up-conversion and down-conversion inversely (e.g., some documents may define such terms for frequency inversely proportional to wavelength).

[0221] Systems that use light conversion materials away from the display light source can be used to absorb light in less useful or harmful wavelength ranges, such as the UV and blue light ranges (especially below about 455 nm), and re-emit light in more useful (from a health perspective) more harmless wavelength ranges, such as the green and red wavelength ranges. In some cases, light can be upconverted from shorter blue wavelengths (below about 455 nm) to longer blue wavelengths that are less harmful and also useful for display illumination. In this way, systems that use light conversion materials away from the light source can modify the emission of light from the display system compared to display systems that do not use such light conversion materials.

[0222] In some examples, a system that uses light conversion or light absorbing materials away from the display's light source can be employed in an electronic device display to reduce blue light emissions. The resulting display system can achieve brightness comparable to a reference display that does not have a light conversion material or light absorbing layer away from the light source, while consuming no more than 10% more energy than the reference display.

[0223] A system using a light conversion material or light absorbing material away from the light source can improve the color balance of a display compared to some known conventional approaches to reducing blue light emission from a display that does not use a light conversion material or light absorbing material away from the light source. Some such known conventional approaches can reduce blue light emission and modify the spectral balance of the light emitted from the display by absorbing or otherwise removing a portion of the blue light from the spectrum. In the systems of the present disclosure, in addition to reducing the amount of harmful blue light emitted from the electronic display device, the light conversion material away from the light source can re-emit light that can contribute to, assist, or improve the color balance of the light emitted from the electronic display device compared to other similar displays with blue light reduction that do not include such light conversion materials. In some embodiments, a display system including a system of the present disclosure incorporating a light conversion material or light absorbing material away from the light source can maintain a D65 white point. In some embodiments, a display system including a system of the present disclosure incorporating a light conversion material or light absorbing material away from the light source can maintain substantially the same correlated color temperature (CCT) as a reference display system that does not include the blue light reduction system of the present disclosure.

[0224] In some embodiments of the systems of the present disclosure, at least one light conversion material can be used in combination with at least one light absorbing material to reduce harmful blue light emissions from the display system and improve or maintain the color balance of the display system.

[0225] The systems of the present disclosure can include multiple light converting or light absorbing materials capable of absorbing light from multiple wavelength ranges, including wavelength ranges other than the UV or blue wavelength ranges.

[0226] The light conversion or light absorbing material can be included or provided in any suitable manner within, on, or with the light management film, reflector, or another layer of the film. In some embodiments, the light conversion or light absorbing material can be extruded, cast, or diffused with the film. In some embodiments, the light conversion or light absorbing material can be coated onto the film. In some embodiments, the light conversion or light absorbing material can be included as a separate film layer or coated onto any of the layers that make up the backlight unit. In some embodiments, the light conversion or light absorbing material can be provided within or with one or more layers of the display system, such as an adhesive used to bond or laminate any suitable layer or film of the display system 100. Such adhesives incorporating light conversion or light absorbing materials are substantially optically clear and exhibit negligible scattering of light transmitted through the adhesive, except for the redirection of light associated with absorption and re-emission by the light conversion material.

[0227] In some embodiments, the light conversion material or light absorbing material can be soluble or insoluble dispersed or dispersed throughout the materials that are components or precursors of any suitable film or layer of the display system 100. The disclosed systems incorporating light conversion materials or light absorbing materials can be custom designed to be retrofitted to existing display systems using selectable design parameters including the selection of light conversion materials, light absorbing materials, and other non-converting blocking or filtering compounds. In other examples, new display systems can be designed that use the disclosed systems incorporating light conversion materials and / or light absorbing materials. By carefully selecting LEDs (and / or other light sources), light conversion materials, light absorbing materials, and other non-converting blocking or filtering compounds, and other optical films and devices, a number of combination approaches can be developed to provide displays that address eye health concerns while providing high display quality.

[0228] While the disclosed and improved embodiments have been shown and described, it will be apparent that various modifications are possible without departing from the scope of the invention. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the disclosed embodiments can be combined with or substituted for one another to form various aspects of the embodiments. Accordingly, no limitations to the disclosed improvements are intended, except as provided by the appended claims. All references cited are incorporated herein by reference in their entirety.

Claims

1. a backlight unit having a light emitting array; A liquid crystal panel; a color filter having one or more absorbing dyes and one or more dye enhancing compounds; The color filter is composed of a plurality of pixels, Each pixel is made up of red, green and blue subpixels. the subpixels are made of a resin; The one or more absorbing dyes and one or more dye enhancement compounds are disposed within a resin of at least one color set of red, green, and blue subpixels within the color filter.

2. 10. The display system of claim 1 further comprising light emitting diodes integrated into the light emitting array, a reflector adjacent to the light emitting array, a diffuser disposed opposite the reflector, a thin film transistor array layer, and a cover glass layer.

3. 2. The display system of claim 1, wherein the liquid crystal panel is adjacent to the color filter and comprises a liquid crystal layer disposed between two panel plates.

4. a first brightness enhancing layer and at least one polarizer; a first polarizer disposed adjacent to the color filter; a second brightness enhancing layer adjacent to the first brightness enhancing layer; 10. The display system of claim 1, wherein a second polarizer is disposed adjacent to the backlight unit.

5. 10. The display system of claim 1, wherein the one or more dye enhancing compounds are at least one of a photoinitiator, a co-initiator, a monomer, and a stabilizer.

6. 10. The display system of claim 1, wherein said one or more dye-strengthening compounds is an antioxidant.

7. 2. The display system of claim 1, wherein said one or more absorbing dyes are soluble primary light absorbing dyes in blue subpixels of said color filter.

8. 8. The display system of claim 7, wherein the one or more absorbing dyes further comprise a secondary light absorbing dye that absorbs light at wavelengths less than 415 nm.

9. 8. The display system of claim 7, wherein the one or more absorbing dyes further include a secondary light absorbing dye that absorbs light at wavelengths greater than 480 nm.

10. 8. The display system of claim 7, wherein the primary light absorbing dye reduces blue light toxicity factor by up to 20%.

11. 2. The display system of claim 1, wherein the one or more absorbing dyes are soluble primary light absorbing dyes in the green subpixels of the color filter.

12. 12. The display system of claim 11, wherein the one or more absorbing dyes further comprise a first secondary light absorbing dye that absorbs light at wavelengths less than 500 nm, a second secondary light absorbing dye that absorbs light at wavelengths greater than 575 nm, or both.

13. 2. The display system of claim 1, wherein said one or more absorbing dyes are soluble primary light absorbing dyes in red subpixels of said color filter.

14. 14. The display system of claim 13, wherein the one or more absorbing dyes further comprise a secondary light absorbing dye that absorbs light at wavelengths less than 590 nm.

15. 2. The display system of claim 1, wherein the one or more absorbing dyes are at least one of a first soluble primary dye that absorbs in the wavelength range of 410-430 nm, a second soluble primary dye that absorbs in the wavelength range of 470-495 nm, and any combination thereof.

16. 10. The display system of claim 1, wherein the one or more absorbing dyes are at least one of an organic dye, a metal complex dye, a porphyrin-based compound, a coumarin, a retinal pigment, and a phthalocyanine compound.

17. 10. The display system of claim 1, wherein the luminance is reduced by no more than 10% compared to a display system not including the one or more absorbing dyes.

18. 2. The display system of claim 1, wherein the color gamut varies by less than 5%.

19. 2. The display system of claim 1, wherein the combination of the one or more absorbing dyes and the one or more dye enhancement compounds is heat resistant and resists a change in gamut coordinates of more than 0.005 along the X-axis and more than 0.005 along the Y-axis after exposure to a temperature of at least 200° C. for at least 30 minutes.

20. 2. The display system of claim 1, wherein the one or more absorbing dyes and the one or more dye enhancement compounds comprise at least one absorbing dye and at least one dye enhancement compound disposed within a resin of each of red, green and blue subpixels within the color filter.

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