LED device using tunable color filters using various neodymium and fluorine compounds

Abstract

The specification and the drawings propose a new device, such as a lighting device, comprising: at least one LED (or OLED) module, which is configured to generate visible light, such as white light; and at least one component, such as an optical component, which comprises a plurality of (two or more) compounds, each compound containing neodymium (Nd) and at least one compound containing fluorine (F), for imparting a desired color filtering effect to provide a desired spectrum, wherein the color of the desired spectrum in the color space is determined by the relative amounts of the two or more compounds in the at least one component.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is a continuation-in-part of co-pending, commonly owned U.S. patent application Ser. No. 14 / 876,366, filed on October 6, 2015, the teachings of which are incorporated herein by reference in their entirety. This application is a continuation-in-part of co-pending, commonly owned International Application No. PCT / CN2014 / 088116, filed on October 8, 2014, the teachings of which are incorporated herein by reference. Technical Field

[0003] The present invention relates generally to lighting applications and related technologies, and more particularly, but not exclusively, to the use of various compounds containing neodymium (Nd) and fluorine (F) to impart desirable color filtering effects in LED lighting devices. Background Art

[0004] As used herein, light emitting diodes (LEDs) also include organic LEDs (OLEDs), which are solid-state semiconductor devices that convert electrical energy into electromagnetic radiation, including visible light (wavelengths of approximately 400 to 750 nm). LEDs typically include a chip (die) of semiconductor material doped with impurities to create a pn junction. The LED chip is electrically connected to an anode and cathode, all of which are typically mounted within an LED package. Compared to other lamps such as incandescent or fluorescent lamps, LEDs that emit visible light are more directional in a narrower beam.

[0005] OLEDs typically include at least one light-emitting electroluminescent layer (organic semiconductor film) positioned between electrodes (at least one of which is transparent). The electroluminescent layer emits light in response to an electric current flowing between the electrodes.

[0006] LED / OLED light sources (lamps) offer various advantages over traditional incandescent and fluorescent lamps, including but not limited to longer life expectancy, higher energy efficiency, and full brightness without the need for warm-up time.

[0007] While LED / OLED lighting is attractive in terms of efficiency, lifetime, flexibility, and other advantages, there remains a need for continued improvement in the color characteristics of LED lighting, particularly in white LED / OLED devices for general lighting and display applications.

[0008] FIG1 is a perspective view of a conventional LED-based lighting device 10 suitable for area lighting applications. The lighting device (also referred to as a "lighting unit" or "lamp") 10 includes a transparent or translucent cover or enclosure 12, a threaded base connector 14, and a housing or base 16 between the cover 12 and the connector 14.

[0009] The LED-based light source (not shown) can be an LED array comprising a plurality of LED devices, which are located at the lower end of the enclosure 12 and adjacent to the base 16. Because LED devices emit visible light in a narrow band of wavelengths, such as green, blue, red, etc., a combination of different LED devices is often used in LED lamps to produce various light colors, including white light. Alternatively, light that appears substantially white can be produced by a combination of light from a blue LED and a phosphor (such as yttrium aluminum garnet:cerium, abbreviated as YAG:Ce) that converts at least some of the blue light of the blue LED into a different color; the combination of the converted light and the blue light can produce light that appears white or substantially white. The LED device can be mounted on a carrier within the base 16 and can be encapsulated on the carrier with a protective cover comprising a refractive index matching material to improve the efficiency of extracting visible light from the LED device.

[0010] In order to improve the ability of the lighting device 10 to emit visible light in an almost omnidirectional manner, the enclosure 12 shown in Figure 1 can be substantially spherical or elliptical. In order to further improve the almost omnidirectional lighting capability, the enclosure 12 can include a material that enables the enclosure 12 to act as an optical diffuser. The material used to make the diffuser can include polyamide (e.g., nylon), polycarbonate (PC), polypropylene (PP), etc. These polymer materials can also include SiO2 to promote the refraction of light, thereby obtaining a white reflective appearance. The inner surface of the enclosure 12 can be provided with a coating (not shown) comprising a phosphor composition.

[0011] While the ability of an LED lamp to produce a white light effect can be enhanced using a combination of different LED devices and / or phosphors, other methods are alternatively or additionally desirable to improve the color characteristics of white light produced by LED devices. Summary of the Invention

[0012] According to one aspect of the present invention, a device includes: at least one light emitting diode (LED) module configured to generate visible light; and at least one component comprising two or more compounds, each compound comprising neodymium (Nd), and at least one of the two or more compounds further comprising fluorine (F), the at least one component being configured to provide a desired spectrum by filtering the generated visible light using the two or more compounds, wherein the color of the desired spectrum in a color space is determined by the relative amounts of the two or more compounds in the at least one component.

[0013] Further in accordance with this aspect of the invention, at least one of the two or more compounds may be neodymium fluoride (NdF3). Additionally, at least one additional compound of the two or more compounds may comprise neodymium oxide (Nd2O3). Additionally, the two or more compounds may comprise Nd3+ ions and F ions.

[0014] Further according to this aspect of the invention, the color of the desired spectrum in the color space can vary within a predetermined region in the color space, the predetermined region being defined at least by the absorption vectors of the two or more compounds. Furthermore, the predetermined region in the color space can be limited to approximately 12 MacAdam ellipses (or the like).

[0015] According further to this aspect of the invention, the at least one LED module may comprise an organic LED. Additionally, the device may comprise an integrated circuit comprising a plurality of LED modules with a corresponding plurality of components.

[0016] Further according to this aspect of the present invention, the at least one component may be an encapsulation layer deposited on top of the at least one LED module. Furthermore, the at least one component may include an additive selected from the group consisting of TiO2, SiO2, and Al2O3 to increase the diffusivity of two or more compounds in the at least one component. Furthermore, the encapsulation layer may be a low-temperature glass, a polymer, a polymer precursor, a polycarbonate, a thermoplastic or thermosetting polymer or resin, a silicone, or a silicone epoxy. Furthermore, the at least one component may also include a phosphor.

[0017] According still further to this aspect of the invention, the at least one component can be an encapsulation layer deposited on another encapsulation layer comprising phosphor, the other encapsulation layer being deposited on top of the at least one LED module.

[0018] Still further according to this aspect of the invention, at least one of the two or more compounds may comprise one or more of Nd-F and Nd-XF compounds, wherein X is one or more of the elements O, N, S, Cl, OH, Na, K, Al, Mg, Li, Ca, Sr, Ba, and Y.

[0019] Further according to this aspect of the present invention, the at least one component may be an optical component comprising a transparent, translucent, or reflective substrate having a coating on a surface thereof, the coating comprising the two or more compounds to provide a desired spectrum by filtering the generated visible light. Furthermore, the coating may have a thickness in the range of about 50 nm to about 1000 μm. Furthermore, the coating may further comprise an additive having a higher refractive index than the two or more compounds, wherein the additive is selected from metal oxides and non-metal oxides comprising at least TiO2, SiO2, and Al2O3. Furthermore, the coating may be disposed on an inner surface of the substrate. Furthermore, the substrate may be a diffuser selected from the group consisting of a bulb, a lens, and a dome surrounding the at least one LED module.

[0020] Further in accordance with this aspect of the invention, the at least one component may be deposited using injection molding or a similar technique. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] These and other features and aspects of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings, in which like numerals represent like parts throughout the figures, wherein:

[0022] FIG. 1 is a perspective view of a conventional LED-based lighting device 10 .

[0023] Figure 2 is a graph of the transmittance of Nd2O3 and NdF3 in the visible spectrum;

[0024] Figure 3 is a color space diagram showing how Nd2O3 and NdF3 compounds incorporated into an optical component (e.g., silicone or polycarbonate) and deposited on a standard LED package (e.g., 80 CRI with a 3000K CCT) can shift the color point of the light source along a vector defined by the spectral absorption of the Nd2O3 and NdF3 compounds;

[0025] 4a is a graph showing transmittance in the visible spectrum of Nd compound mixtures containing different amounts of Nd2O3 and NdF3 according to an embodiment of the present invention;

[0026] 4b is a graph of simulated emission of a lamp (e.g., an LED lamp) in the visible spectrum using filters having various Nd compound mixtures shown in FIG. 4a, according to an embodiment of the present invention;

[0027] Figure 5 is a color space diagram comparing the color point of a standard 3000K LED lamp with simulated color points of LED lamps including filters with various Nd compound mixtures shown in Figures 4a and 4b, respectively, according to an embodiment of the present invention;

[0028] 6a-6d are non-limiting examples of LED-based lighting devices incorporating ND-F compounds (or more generally ND-XF compounds as described herein) and phosphors to impart favorable visible absorption / generation characteristics according to various embodiments of the present invention;

[0029] Figure 7 is a cross-sectional view of an LED-based lighting device according to one embodiment of the present invention;

[0030] Figure 8 is a cross-sectional view of an LED-based lighting device according to another embodiment of the present invention;

[0031] Figure 9is a perspective view of an LED-based lighting device according to yet another embodiment of the present invention;

[0032] Figure 10 is a perspective view of an LED-based lighting device according to yet another embodiment of the present invention. DETAILED DESCRIPTION

[0033] This article proposes a new device, such as a lighting device, which includes: at least one LED (or OLED) module, which is configured to generate visible light, such as white light; and at least one component, such as an optical component, which includes a plurality of (two or more) compounds, each compound containing neodymium (Nd) and at least one compound containing fluorine (F), for imparting a desired color filtering effect to provide a desired spectrum, wherein the color of the desired spectrum in a color space is determined by the relative amounts of the two or more compounds in the at least one component.

[0034] For example, according to one embodiment of the present invention, the at least one component (optical component) can be a polymer substrate (e.g., silicone, polycarbonate, etc.) comprising two compounds: the first compound can be neodymium oxide (Nd2O3), and the second compound can be neodymium fluoride (NdF3), as is described in detail herein. Neodymium compounds absorb yellow light in the 560-600nm range, which changes the color point of the LED system. Adding a single compound can shift the color point along a line in the CIE 1931 color space (with chromaticity coordinates CCX and CCY). By using two or more compounds, the color point can be shifted anywhere within the area of ​​the CIE color space (hereinafter referred to as the "color space"). This allows for a greater degree of customization of the color of the LED system for specific applications, as described herein. Figure 3 shown.

[0035] In other words, neodymium compounds (e.g., Nd2O3 and NdF3 in the above-described embodiments) can be added in various amounts to alter the composition of the optical components used to control the color point of the resulting light. As each component is added, the different absorption spectra of the two (or more) components cause the color point of the LED system to shift in different directions (i.e., in both the CCX and CCY directions). The color point shift vectors for the various compounds comprising Nd and F described herein can then define a region within the CIE color space within which any color point can be achieved with the same LED by varying the relative amounts of the two or more compounds, as described herein.

[0036] According to another embodiment, scattering elements such as titanium dioxide (TiO2), aluminum oxide (Al2O3), silicon dioxide (SiO2), etc. can be added to the polymer matrix to increase the diffusivity of various Nd and F compounds in the optical component. Variation of the three variables (e.g., the weight loading of TiO2, NdF3, and Nd2O3 in the above example) can allow the creation of a variety of specialized optical components to achieve the desired spectrum and distribution.

[0037] Furthermore, according to one embodiment of the present invention, at least one compound (or more than one) may contain the elements of neodymium (Nd) and fluorine (F), and optionally one or more other elements. Typically, such a compound contains Nd 3+ ions and F ions. For the purposes of the present invention, "Nd-F compounds" should be interpreted broadly to include compounds comprising neodymium and fluoride and optionally other elements.

[0038] According to another embodiment, the component may include a composite / encapsulation layer on the surface of the LED (OLED) chip, such that various compounds including Nd and F disclosed herein may be blended (dispersed) in the encapsulation layer, for example, together with a phosphor, to achieve a favorable visible light absorption profile. The composite / encapsulation layer may be formed using low-temperature glass, a polymer (e.g., polycarbonate), a polymer precursor, a siloxane (polymer), or a siloxane epoxy resin or precursor, etc.

[0039] According to another embodiment, the optical component can be a transparent, translucent reflective, or translucent (partially reflective and transmissive) substrate, and the coating on the surface of the substrate contains a plurality of Nd and F components as described herein. When the visible light passes through the optical component, the coating can exert a color filtering effect on the visible light generated by the LED module, for example, filtering visible light within the yellow light wavelength range (e.g., wavelengths from about 560 nm to about 600 nm) to provide a desired spectrum.

[0040] In addition, the transparent or translucent substrate of the optical component can be a diffuser, such as a bulb, lens, and an envelope surrounding at least one LED chip. Furthermore, the substrate can be a reflective substrate, and the LED chip can be arranged on the exterior of the substrate. A multi-compound coating (comprising the Nd and F multi-compounds described herein) can be provided on the surface of the substrate, and the thickness of the coating should be sufficient to achieve a color filtering effect. The thickness can generally be in the range of 50 nm to 1000 μm, with a preferred thickness between 100 nm and 500 μm.

[0041] The resulting devices can exhibit improvements in optical parameters through filtering using Nd and Nd-F compounds / materials that have intrinsic absorption in the visible light region between approximately 530 nm and 600 nm to enhance CSI (color saturation index), CRI (color rendering index), R9 (color rendering value), and color rendering (lighting preference index, LPI). R9 is defined as one of six saturated test colors not used in calculating CRI. "Color rendering" is a parameter of emitted light based on the LPI version, which is described in co-pending, commonly owned International Application No. PCT / US2014 / 054868, filed on September 9, 2014 (published as WO2015 / 035425 on March 12, 2015), and is incorporated herein by reference in relevant portions.

[0042] In one embodiment, at least one of the various compounds described herein may contain Nd 3+ ions and F - ions, and may be a Nd-F compound or a Nd-XF compound. As used herein, "Nd-F compound" should be broadly interpreted to include compounds comprising neodymium and fluoride and optionally other elements. Such a compound comprising neodymium and fluoride may comprise neodymium fluoride or neodymium oxyfluoride (e.g., NdO x F y , wherein 2x+y=3, such as Nd4O3F6) or neodymium fluoride containing adventitious water and / or oxygen, or neodymium hydroxide fluoride (e.g., Nd(OH) a F b , where a+b=3), or various other compounds comprising neodymium and fluoride, which will become apparent from the description below.

[0043] In some embodiments, one of the multiple compounds may be NdF3 or NdFO. For Nd-XF compounds, X is at least one element selected from the group consisting of: an element that forms a compound with neodymium, such as oxygen, nitrogen, sulfur, and chlorine; or at least one metal element that forms a compound with fluorine, such as Na, K, Al, Mg, Li, Ca, Sr, Ba, and Y, or a combination of these elements, the metal element being different from neodymium. Specific examples of Nd-XF compounds may include: neodymium oxyfluoride (Nd-OF) compounds; Nd-XF compounds in which X may be Mg and Ca or may be Mg, Ca, and O; and other compounds containing Nd-F, including perovskite structures doped with neodymium. Certain Nd-XF compounds may advantageously achieve broader absorption at a wavelength of approximately 580 nm.

[0044] As mentioned above, one component / optical component may be a polymer substrate (eg silicone, polycarbonate, etc.) comprising, for example, the two compounds Nd2O3 and NdF3. Figure 2 is a graph of the transmittance in the visible spectrum of Nd2O3 (1.0% in 1.3 mm thick silicone with a refractive index of 1.54), represented by curve 22, and NdF3 (2.9% in 1.3 mm thick silicone with a refractive index of 1.54), represented by curve 20. As can be seen, the various materials share many similar absorption features, especially in the yellow region (e.g., about 570 nm to about 600 nm). Figure 2 The different absorption peaks shown drive different color shift vectors for each component (Nd2O3 and NdF3) in the color space, as shown in Figure 3 As further shown, by combining these two compounds, color points can be achieved that cannot be achieved with a single Nd compound or neodymium glass (Nd2O3 in SiO2).

[0045] In use, the LED chip / die can be encapsulated with an encapsulant (e.g., silicone, epoxy resin, acrylic resin, etc.); the encapsulant may include Nd2O3 and NdF3 materials or generally Nd and F-based compounds described herein, so that, for example, Nd2O3 and NdF3 in silicone can be deposited directly on the LED chip or on an LED chip array (e.g., chip-on-board array, COB array), as further described herein.

[0046] Figure 3 is a color space diagram showing how Nd2O3 and NdF3 compounds incorporated into an optical component (such as silicone or polycarbonate) and deposited on a standard LED package (e.g., 80 CRI, which has a 3000K CCT) can shift the color point of the light source along vectors 30 and 32 defined by the spectral absorption of the Nd2O3 and NdF3 compounds, respectively.

[0047] from Figure 3As can be clearly seen in the diagram, by varying the relative amounts of Nd2O3 and NdF3 compounds—that is, by shifting the emitter's color point along vectors 30 and 32 defined by the spectral absorption of the Nd2O3 and NdF3 compounds, respectively—this system theoretically allows for any color point within the triangle ABC produced by a standard 3000K LED. However, because large energy losses due to high filtering are undesirable, this system can be practically limited to a smaller region 34, such as 12 MacAdam ellipses, or some other region size arbitrarily chosen based on the application and the end user's willingness to sacrifice LPW (lumens per watt) to achieve a color point very far from the starting color. Region 34 is defined by lines BD and BE and curve 36. Any practical color point within region 34 can be achieved over a wide range of relative amounts and diffusion levels of the Nd2O3 and NdF3 compounds, allowing a given color point to be applied in different LED systems requiring different beam-shaping properties of the optics. In contrast, adding neodymium glass (the conventional approach) only allows the color point to be shifted to a single point 38 (or along a vector if the glass thickness is varied). 4a, 4b and 5 show further examples for practicing the embodiments disclosed herein.

[0048] FIG4a is an exemplary graph of transmittance in the visible spectrum of neodymium compound mixtures containing varying amounts of Nd2O3 and NdF3 in a silicone tape according to one embodiment of the present invention. Curve 42a corresponds to a 1.3 mm thick silicone tape containing 4% NdF3 and 1% Nd2O3, curve 44a corresponds to a 1.3 mm thick silicone tape containing 5% NdF3 and 0.5% Nd2O3, curve 46a corresponds to a 1.3 mm thick silicone tape containing 3.5% NdF3 and 0.5% Nd2O3, and curve 48a corresponds to a 1.3 mm thick silicone tape containing 3.5% NdF3 and 1.8% Nd2O3.

[0049] FIG4 b is a graph of simulated emission in the visible spectrum of a lamp (e.g., an LED lamp) using filters having various Nd compound mixtures as shown in FIG4 a, according to an embodiment of the present invention. In FIG4 b , curve 42 b is for a simulated LED lamp having a 1.3 mm thick silicone ribbon containing 4% NdF3 and 1% Nd2O3, curve 44 b is for a simulated LED lamp having a 1.3 mm thick silicone ribbon containing 5% NdF3 and 0.5% Nd2O3, curve 46 b is for a simulated LED lamp having a 1.3 mm thick silicone ribbon containing 3% NdF3 and 0.5% Nd2O3, and curve 48 b is for a simulated LED lamp having a 1.3 mm thick silicone ribbon containing 3.5% NdF3 and 1.8% Nd2O3.

[0050] Figure 5is a color space diagram comparing the color point of a standard 3000K LED lamp with the color points of LED lamps including filters with various Nd compound mixtures shown in Figures 4a and 4b, respectively, according to an embodiment of the present invention. Figure 5 , color point 52 is used for a simulated LED lamp having a 1.3 mm thick silicone ribbon containing 4% NdF3 and 1% Nd2O3, color point 54 is used for a simulated LED lamp having a 1.3 mm thick silicone ribbon containing 5% NdF3 and 0.5% Nd2O3, color point 56 is used for a simulated LED lamp having a 1.3 mm thick silicone ribbon containing 3% NdF3 and 0.5% Nd2O3, and color point 58 is used for a simulated LED lamp having a 1.3 mm thick silicone ribbon containing 3.5% NdF3 and 1.8% Nd2O3.

[0051] Figures 4a, 4b, and 5 illustrate how varying the relative amounts of NdF3 and Nd2O3 in the filter component of an (LED) lamp can alter the lamp's color temperature and shift its emission spectrum (e.g., absorption peak near the 570-600 nm wavelength range) to provide a desired lamp spectrum with a desired color temperature and a sufficient level of transmitted lumen power (e.g., "whitening" the light source), thereby further improving other light parameters such as CSI, CRI, R9, and renderability. "Renderability" is a parameter of emitted light based on an LPI version described in co-pending, commonly owned International Application No. PCT / US2014 / 054868, filed September 9, 2014 (published as WO2015 / 035425 on March 12, 2015), and incorporated herein by reference in relevant portions.

[0052] In another embodiment, corresponding relative amounts of multiple Nd and F compounds can be blended into the packaging material together with one or more luminescent materials (e.g., phosphors). For example, corresponding relative amounts of multiple Nd and F compounds can be blended with a yellow-green phosphor and / or a red phosphor. For example, multiple Nd and F compounds can be blended with a Ce-doped YAG phosphor and / or a conventional red nitride phosphor (e.g., Eu 2+ In another example, Nd and F compounds can be blended with YAG:Ce phosphor and red nitride phosphor in siloxane to encapsulate blue / UV emitting LEDs.

[0053] Figures 6a-6d show different non-limiting examples of LED-based lighting devices 60a, 60b, 60c and 60d, respectively, according to various embodiments of the present invention, which incorporate various compounds of Nd and F, as described herein, and phosphors to achieve favorable visible light absorption / generation characteristics. In Figures 6a-6d, the LED-based lighting device 60a, 60b, 60c or 60d includes a dome 62, which can be an optically transparent or translucent substrate surrounding an LED chip 65 mounted on a printed circuit board (PCB) 66. The leads provide current to the LED chip 65, causing it to emit radiation. The LED chip can be any semiconductor light source, especially a blue or ultraviolet light source that can produce white light when the radiation it emits is directed onto the phosphor. In particular, the semiconductor light source can be based on a semiconductor light source that is generalized as In i Ga j Al k

[0014] A blue / ultraviolet (UV) emitting LED based on a nitride compound semiconductor of InGaN, wherein I, j, and k are integers each having a value of 1 or 0 (including, for example, InGaN, AlN, AlGaN, AlGaInN device structures), having an emission wavelength greater than about 200 nm and less than about 550 nm. More specifically, the chip can be a near-UV or blue emitting LED having a peak emission wavelength from about 400 nm to about 500 nm. Even more specifically, the chip can be a blue emitting LED having a peak emission wavelength in the range of about 440-460 nm. Such LED semiconductors are known in the art.

[0054] According to one embodiment shown in FIG6a , a polymer composite layer (encapsulant compound) 64a may include various Nd and F compounds, as described herein, blended with a phosphor to impart advantageous visible light absorption / generation properties according to various embodiments described herein. This compound layer 64a may be disposed directly on the surface of an LED chip 65 and radiatively couple to the chip. “Radiatively coupling” means that radiation from the LED chip is transferred to the phosphor, and the phosphor emits radiation of a different wavelength. In a specific embodiment, the LED chip 65 may be a blue LED, and the polymer composite layer may include a blend of corresponding relative amounts of various Nd and F compounds with a yellow-green phosphor (e.g., cerium-doped yttrium aluminum garnet, Ce:YAG). The blue light emitted by the LED chip mixes with the yellow-green light emitted by the phosphor of the polymer composite layer, and the net emission appears as white light filtered by the various Nd and F compounds. Thus, the LED chip 65 may be surrounded by a layer of encapsulant material 64a. The encapsulant material may be a low-temperature glass, a thermoplastic or thermosetting polymer or resin, or a silicone or epoxy resin. The LED chip 65 and the sealant material layer 64a can be encapsulated within the housing (confined by the dome 62). Alternatively, the LED device 60a can include only the sealant layer 64a without the outer housing / dome 62. In addition, as described herein, scattering particles can be embedded in the sealant material to increase the diffusivity of various compounds of Nd and F. The scattering particles can be, for example, aluminum oxide (Al2O3), silicon dioxide (SiO2), or titanium dioxide (TiO2). In addition, the scattering particles can effectively scatter the directional light emitted from the LED chip, preferably with negligible absorption.

[0055] In order to form a polymer composite layer containing a plurality of Nd and F compounds in corresponding relative amounts as described herein on the surface of the LED chip, the particles can be dispersed in a polymer or polymer precursor, in particular a silicone, polycarbonate, silicone epoxy resin or its precursor. Such materials are well known for LED packaging. The dispersed mixture can be applied to the chip by any suitable process, such as using injection molding (or casting and extrusion optical components or similar techniques), and particles with greater density or particle size, or greater density and greater particle size, preferentially settle in the area near the LED chip to form a layer with a gradient composition. Sedimentation can occur during coating or curing of the polymer or precursor and can be promoted by centrifugation processes known in the art. It should also be noted that the dispersion parameters of the phosphor and the Nd and F compounds, such as particle density and particle size and process parameters, can be selected to provide the phosphor material closer to the LED chip 65 than the Nd and F compounds, so as to provide appropriate filtering of the light generated by the phosphor components by the Nd and F compounds.

[0056] In an alternative exemplary embodiment shown in Figure 6b, the phosphor layer 64b can be a conventionally manufactured encapsulant layer, and a separate encapsulant layer 68b having various compounds of Nd and F can be deposited on top of the phosphor layer 64b, for example: using appropriate conventional deposition / particle dispersion techniques in a polymer or polymer precursor.

[0057] In another exemplary embodiment shown in FIG6c, a composite layer 68c comprising various compounds of Nd and F can be coated on the outer surface of dome (shell) 62. The properties of coating layer 68b are similar to the properties of sealant layer 68b having various compounds of Nd and F in FIG6b. Alternatively, coating layer 68c in FIG6c can be deposited on the inner surface of dome 62. Figure 7-10 Further implementation details regarding the coating of the dome / substrate are discussed. Note that the dome 62 itself can be transparent or translucent.

[0058] In yet another exemplary embodiment, as shown in FIG6 d , a dome (housing) 62 can be used to deposit multiple Nd and F compound composite layers / coatings 68 d on the outer surface of the dome 62, and a phosphor coating 64 d is deposited on the inner surface of the dome 62. It should also be noted that this approach can have different variations. For example, both coatings 64 d and 68 d can be deposited on one surface (either the outer or inner surface) of the dome 62, with the phosphor coating 64 d being closer to the LED chip 65 than the coating 68 d. Furthermore, the coatings 64 d and 68 d (when deposited on one surface of the dome 62) can be combined in one layer, similar to the sealant compound layer 64 a in FIG6 a. Note that the dome 62 itself can be transparent, translucent, or translucent in order to achieve different variations of the example shown in FIG6 d .

[0059] Below are several non-limiting examples of LED-based lighting devices using coatings described herein comprising various compounds of Nd and F that result in a desired color filter effect.

[0060] Figure 7 is an LED-based lighting device suitable for area lighting applications according to one embodiment of the present invention. The LED-based lighting device (which may also be referred to as a "lighting unit" or "lamp") is an LED lamp 70 configured to provide nearly omnidirectional lighting capabilities. Figure 7 As shown, LED lamp 70 includes a bulb 72, a connector 74, a base 76 located between bulb 72 and connector 74, and a coating 78 on the outer surface of bulb 72. Coating 78 includes various compounds of Nd and F as described herein. In other embodiments, bulb 72 can be replaced by other transparent or translucent substrates. Alternatively, coating 78 can be applied to the inner surface of bulb 72, which can be transparent or translucent.

[0061] Figure 8 FIG. 8 is an LED-based lighting device 80 according to another embodiment of the present invention. Figure 8 As shown, the LED-based lighting device is a pendant lamp 80 (LED chips not shown). Pendant lamp 80 includes a hemispherical substrate 82 and a coating 88 comprising various compounds of Nd and F as described herein; coating 88 is on the inner surface of hemispherical substrate 82. Alternatively, coating 88 can be applied to the outer surface of hemispherical substrate 82, which can be transparent or translucent.

[0062] Figure 9 is an LED-based lighting device according to another embodiment of the present invention. Figure 9 As shown, the LED-based lighting device is a lens 90, and the lens 90 includes a flat substrate 92. In this embodiment, the flat substrate 92 includes a Nd and F multi-compound coating (not shown) on its outer surface.

[0063] Figure 10 FIG1 is another embodiment of an LED-based lighting device 100 according to the present invention. The LED-based lighting device 100 includes a bulb 102, at least one LED chip 105, and a reflective substrate 106. The reflective substrate 106 is configured to reflect visible light generated by the LED chip 105. In some embodiments, the reflective substrate 106 includes a coating (not shown) of a plurality of Nd and F compounds on its outer surface to provide desired filtering. Figure 10 In the embodiment of the present invention, the dome (102) can be constructed of a diffusive material so that a certain amount of light from the LED will pass through and a certain amount of light will be reflected back into the cavity (these amounts depend on how diffusive the dome material is). Depending on the diffusivity of the dome 102, the reflected light will be specularly or diffusely reflected. These diffuse and / or specular reflections from the dome 102 will be incident on a reflective substrate 106 coated according to one of the embodiments described herein. Alternatively, the dome 102 can be constructed of a broadband semi-reflective material to provide the same functionality.

[0064] The coating materials described herein, including compounds containing Nd3+ ions and F ions, may have minimal optical scattering (diffusion) effects; alternatively, they may induce substantial optical scattering of light passing therethrough. To increase the scattering angle, the coating may include discrete particles of an organic or inorganic material. Alternatively, the organic or inorganic material may consist solely of discrete particles of the various Nd and F compounds described herein, and / or a mixture of discrete particles of the various Nd and F compounds and particles of at least one other different material.

[0065] In one embodiment, a suitable particle size of the organic or inorganic material may be from about 1 nm to about 10 μm. Figure 7For the LED lamp 70 shown, in order to maximize the scattering angle so that the LED lamp 70 can achieve omnidirectional illumination, the particle size can be selected to be much smaller than 300 nm to maximize the efficiency of Rayleigh scattering.

[0066] Although not intended to be limiting, the Nd and F multiple compound coating can be applied by, for example, spraying, roller coating, meniscus or dipping, stamping, screen coating, dispensing, rolling, brushing, bonding, electrostatic coating, or any other method that can provide a coating of uniform thickness. Three non-limiting examples of how to provide a Nd and F multiple compound coating on a substrate are described below.

[0067] In one embodiment, Figure 7 As shown, the coating 37 can be applied to the bulb 72 by a bonding method. The LED lamp 70 may include a bonding layer (not shown) between the bulb 72 and the coating 78, and the bonding layer may include an organic adhesive or an inorganic adhesive. The organic adhesive may include epoxy resin, silicone resin adhesive, acrylic resin, etc. The inorganic adhesive may include silicate inorganic adhesive, sulfate adhesive, phosphate adhesive, oxide adhesive, borate adhesive, etc.

[0068] In another embodiment, Figure 7 As shown, coating 78 can be applied to the outer surface of bulb 72 by a spray coating method. First, a liquid mixture is formed, which contains, for example, corresponding relative amounts of Nd2O3 and NdF3 compounds, silica, a dispersant such as DISPEX A40, water, and optionally TiO2 or Al2O3. Subsequently, the formed liquid mixture is sprayed onto bulb 72. Finally, bulb 72 is cured to obtain coated LED lamp 70.

[0069] In one embodiment, Figure 7 As shown, coating 78 can be applied to the outer surface of bulb 72 by electrostatic coating. First, a charged powder composed of, for example, Nd2O3 and NdF3 compounds, SiO2, and Al2O3 in corresponding relative amounts is prepared. The powder is then applied to bulb 72, which has an opposite charge.

[0070] In another embodiment of the present invention, both the spray coating method and the electrostatic coating method can use materials that do not contain organic solvents or organic compounds, which can extend the service life of LED lighting equipment and avoid discoloration typically caused by sulfonation.

[0071] In another embodiment, in order to promote the refraction of light to obtain a white reflective appearance, the coating may further include an additive having a higher refractive index than various Nd and F compounds. The additive may be selected from at least one of metal oxides or non-metal oxides, such as TiO2, SiO2, and Al2O3.

[0072] Unless otherwise defined, the technical and scientific terms used herein have the same meanings as those generally understood by those of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," etc., used herein do not represent any order, quantity, or importance, but are used to distinguish one element from another. In addition, the terms "one" and "a kind of" do not represent a quantitative limitation, but rather represent the presence of at least one of the cited items. The use of "including," "comprising," or "having" and variations thereof herein is intended to encompass the items listed thereafter and their equivalents, as well as additional items. The terms "connect" and "couple" are not limited to physical or mechanical connections or couplings, and may include electrical and optical connections or couplings, whether direct or indirect.

[0073] In addition, the skilled person will recognize the interchangeability of various features from different embodiments. Those skilled in the art can mix and match the various features described, as well as other known equivalents for each feature, to construct additional systems and techniques in accordance with the principles of this disclosure.

[0074] When describing alternative embodiments of the claimed apparatus, specific terminology is employed for clarity. However, the present invention is not intended to be limited to the specific terminology so selected. Therefore, it should be understood that each specific element includes all technical equivalents that operate in a similar manner to achieve similar functions.

[0075] It should be understood that the foregoing description is intended to illustrate and not to limit the scope of the invention, which is defined by the scope of the appended claims. Other embodiments are within the scope of the appended claims.

[0076] It should be noted that the various non-limiting embodiments described and claimed herein can be used alone, in combination, or in selective combination for specific applications.

[0077] Furthermore, some of the various features of the above-described non-limiting embodiments may be used to advantage without the corresponding use of other described features. Therefore, the foregoing description should be considered as merely illustrative of the principles, teachings, and exemplary embodiments of this invention, and not in limitation thereof.

Claims

1. A device comprising: at least one light emitting diode (LED) module configured to generate visible light; Phosphors; and At least one component comprising two or more compounds, wherein at least one of the two or more compounds comprises Nd2O3, and wherein at least one other of the two or more compounds comprises a x F y Neodymium oxyfluoride, wherein 2x+y=3; or having the formula Nd(OH) a F b Neodymium hydroxide fluoride, where a+b=3, The at least one component is configured to provide a desired spectrum by filtering the generated visible light using the two or more compounds, wherein the color of the desired spectrum in color space is determined by the relative amounts of the two or more compounds in the at least one component; and wherein the at least one component comprises an amount of neodymium oxyfluoride or neodymium hydroxide fluoride greater than the amount of Nd2O3, the neodymium oxyfluoride having the formula NdO x F y wherein 2x+y=3; or the neodymium hydroxide fluoride has the formula Nd(OH) a F b , where a+b=3.

2. The device according to claim 1, wherein: The at least one compound of the two or more compounds is neodymium fluoride (NdF3).

3. The device according to claim 1, wherein: The color of the desired spectrum in the color space varies within a predetermined region in the color space, the predetermined region being defined at least by absorption vectors of the two or more compounds.

4. The device according to claim 3, wherein: The predetermined area in the color space is limited to approximately 12 MacAdam ellipses.

5. The device according to claim 1, wherein: The two or more compounds include Nd 3+ Ions and F - ion.

6. The device according to claim 1, wherein: The at least one component is an encapsulation layer deposited on top of the at least one LED module.

7. The device according to claim 6, wherein: The encapsulation layer is low temperature glass, polymer, polymer precursor, polycarbonate, thermoplastic or thermosetting polymer or resin, siloxane or siloxane epoxy resin.

8. The device according to claim 1, wherein: The at least one component is an encapsulation layer deposited on another encapsulation layer comprising a phosphor, the other encapsulation layer being deposited on top of the at least one LED module.

9. The device according to claim 1, wherein: At least one of the two or more compounds comprises one or more of Nd-F and Nd-XF compounds, wherein X is one or more of the elements O, N, S, Cl, OH, Na, K, Al, Mg, Li, Ca, Sr, Ba, and Y.

10. The device according to claim 1, wherein: The at least one component is an optical component, the optical component includes a transparent, translucent or reflective substrate, and a coating is provided on a surface of the substrate, the coating comprising the two or more compounds to provide the desired spectrum by filtering the generated visible light.

11. The device according to claim 10, wherein: The coating has a thickness in the range of about 50 nanometers to about 1000 micrometers.

12. The device according to claim 11, wherein The coating further comprises an additive having a higher refractive index than the two or more compounds, and wherein the additive is selected from metal oxides and non-metal oxides including at least TiO2, SiO2 and Al2O3.

13. The device according to claim 11, wherein: The coating is disposed on the inner surface of the substrate.

14. The device according to claim 11, wherein: The substrate is a diffuser selected from the group consisting of a bulb, a lens, and a dome surrounding the at least one LED module.

15. The apparatus according to claim 1, wherein: The apparatus includes an integrated circuit containing a plurality of LED modules having a corresponding plurality of components.

16. The apparatus according to claim 1, wherein: The at least one component is deposited using injection molding.

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