CN108369983B

CN108369983B - LED device employing tunable color filtering using various neodymium and fluorine compounds

Info

Publication number: CN108369983B
Application number: CN201680072489.0A
Authority: CN
Inventors: K.J.本纳; G.R.艾伦; 蔡登科; T.克林; 何建民
Original assignee: GE Lighting Solutions LLC
Current assignee: Home Lighting Usa Co ltd; Karent Lighting Solutions Co ltd; Saiwante Technology Co ltd
Priority date: 2015-12-11
Filing date: 2016-12-06
Publication date: 2021-05-07
Anticipated expiration: 2036-12-06
Also published as: MX389576B; CA3007011C; TWI772277B; CN113130721B; KR20180093989A; JP2019501526A; MX2018007034A; KR102726002B1; CN113130721A; TW201739895A; WO2017100190A1; CN108369983A; CA3007011A1; JP7005494B2

Abstract

The description and drawings present a new device, such as a lighting device, comprising: at least one LED (or OLED) module configured to generate visible light, eg white light; and at least one component, eg an optical component, It includes a plurality (two or more) of compounds, each compound comprising neodymium (Nd) and at least one compound comprising fluorine (F), for imparting a desired color filtering effect to provide a desired spectrum, 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.

Description

LED device employing tunable color filtering using various neodymium and fluorine compounds

Cross Reference to Related Applications

This application is a continuation-in-part application of co-pending, co-owned U.S. patent application serial No. 14/876366 filed on 6/10/2015, the teachings of which are incorporated herein by reference in their entirety. This application is a continuation-in-part application of co-pending, commonly owned international application PCT/CN2014/088116 filed on 8/10/2014, the teachings of which are incorporated herein by reference.

Technical Field

The present invention relates generally to lighting applications and related technologies, and more particularly, but not exclusively, to the use of various compounds including neodymium (Nd) and fluorine (F) to impart a desired color filtering effect in LED lighting devices.

Background

Light Emitting Diodes (LEDs) as used herein also include organic LEDs (oleds), which are solid state semiconductor devices that convert electrical energy into electromagnetic radiation including visible light (wavelengths of about 400 to 750 nm). LEDs typically comprise a chip (die) of semiconductor material that is doped with impurities to create a p-n junction. The LED chip is electrically connected to an anode and a cathode, all of which are typically mounted within the LED package. LEDs that emit visible light are more directional in a narrower beam of light than other lamps, such as incandescent or fluorescent lamps.

OLEDs typically comprise at least one light-emitting electroluminescent layer (organic semiconductor film) located between electrodes (at least one of which is transparent). The electroluminescent layer emits light in response to current flowing between the electrodes.

LED/OLED light sources (lamps) offer various advantages over conventional 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.

Although LED/0LED lighting is attractive in efficiency, lifetime, flexibility, and other advantages, there is a continuing need to improve the color characteristics of LED lighting, particularly in white LED/PLED devices for general lighting and display applications.

Fig. 1 is a perspective view of a conventional LED-based lighting device 10 suitable for area lighting applications. The lighting device (which may also be 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 enclosure 12 and the connector 14.

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

To enhance the ability of the lighting device 10 to emit visible light in an almost omnidirectional manner, the enclosure 12 shown in fig. 1 may be substantially spherical or elliptical. To further enhance nearly omnidirectional illumination capabilities, the enclosure 12 may include materials that enable the enclosure 12 to function as an optical diffuser. Materials used to make diffusers may include polyamides (e.g., nylon), Polycarbonate (PC), polypropylene (PP), and the like. These polymeric materials may also include SiO₂To promote refraction of light to obtain a white reflective appearance. The inner surface of the enclosure 12 may be provided with a coating (not shown) comprising a phosphor composition.

While the ability of an LED lamp to produce a white light effect may be enhanced with the use of a combination of different LED devices and/or phosphors, alternatively or in addition, other methods are desired to improve the color characteristics of the white light produced by the LED devices.

Disclosure of Invention

According to one aspect of the invention, an apparatus comprises: 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 compound of the two or more compounds further comprising fluorine (F), the at least one component configured to provide a desired spectrum by filtering the generated visible light using the two or more compounds, wherein a color of the desired spectrum in a color space is determined by a relative amount of the two or more compounds in the at least one component.

Further according to the method of the inventionThe at least one compound of the two or more compounds may be neodymium fluoride (NdF)₃). Further, at least one additional compound of the two or more compounds may include neodymium oxide (Nd)₂O₃). In addition, the two or more compounds may contain Nd³⁺Ions and F ions.

Further according to this aspect of the invention, the color of the desired spectrum in the color space may 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. Further, the predetermined area in the color space may be limited to about 12 macadam ellipses (etc.).

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

According further to this aspect of the invention, the at least one component may be an encapsulation layer deposited on top of the at least one LED module. Further, the at least one component may comprise a material selected from the group consisting of TiO₂、SiO₂And Al₂O₃An additive of the group to increase the diffusivity of two or more compounds in the at least one component. Further, the encapsulation layer may be a low temperature glass, a polymer precursor, a polycarbonate, a thermoplastic or thermoset polymer or resin, a siloxane or siloxane epoxy. Further, the at least one component may further include a phosphor.

Still further according to this aspect of the invention, the at least one component may be an encapsulation layer deposited on a further encapsulation layer comprising phosphor, the further encapsulation layer being deposited on top of the at least one LED module.

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

Still further according to this aspect of the 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 the desired spectrum by filtering the generated visible light. Further, the thickness of the coating may be in the range of about 50nm to about 1000 μm. Furthermore, the coating may further comprise an additive having a refractive index higher than the two or more compounds, and wherein the additive is selected from the group comprising at least TiO₂，SiO₂And Al₂O₃Metal oxides and non-metal oxides of (a). Further, the coating may be disposed on an inner surface of the substrate. Further, 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.

Further according to this aspect of the invention, the at least one component may be deposited using injection molding or similar techniques.

Drawings

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 characters represent like parts throughout the drawings, wherein:

fig. 1 is a perspective view of a conventional LED-based lighting device 10.

FIG. 2 is Nd₂O₃And NdF₃A graph of the transmission in the visible spectrum of (a);

FIG. 3 is a color space diagram showing Nd incorporated into an optical component (e.g., siloxane or polycarbonate) and deposited on a standard LED package (e.g., 80CRI with 3000K CCT)₂O₃And NdF₃How the compound can follow the Nd₂O_aAnd NdF₃The spectral absorption of the compound shifts the color point of the light source by a defined vector;

FIG. 4a is a graph containing varying amounts of Nd, according to an embodiment of the invention₂O₃And NdF₃Of the Nd compound mixtureLine drawing;

fig. 4b is a graph of simulated emissions of a lamp (e.g., an LED lamp) in the visible spectrum using a filter with the various Nd compound mixtures shown in fig. 4a, in accordance with an embodiment of the present invention;

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

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

FIG. 7 is a cross-sectional view of an LED-based lighting device according to one embodiment of the present invention;

FIG. 8 is a cross-sectional view of an LED-based lighting device according to another embodiment of the present invention;

FIG. 9 is a perspective view of an LED based illumination device according to yet another embodiment of the present invention;

FIG. 10 is a perspective view of an LED based illumination device according to yet another embodiment of the invention.

Detailed Description

A new device, for example a lighting device, is proposed herein, which comprises: at least one LED (or OLED) module configured to generate visible light, such as white light; and at least one component, such as an optical component, comprising a plurality (two or more) of compounds, each compound comprising neodymium (Nd) and at least one compound comprising 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.

For example, according to one embodiment of the present invention, the at least one component (optical component) may be a polymeric substrate (e.g., siloxane, polycarbonate, etc.) comprising two compounds: the first compound may be neodymium oxide(Nd₂O₃) And the second compound may be neodymium fluoride (NdF)₃) This is the case as described in detail herein. The neodymium compound absorbs yellow light in the range 560-600nm, which changes the color point of the LED system. The addition of 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 "color space"). This allows a greater degree of customization of the color of the LED system for a particular application, as shown in fig. 3 herein.

In other words, a neodymium compound (e.g., Nd in the above-described embodiment)₂O₃And NdF₃) Can be added in various amounts to vary the composition of the optical components used to control the color point of the resulting light. When 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 of the various compounds described herein, including Nd and F, 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.

According to another embodiment, a material such as titanium dioxide (TiO2), aluminum oxide (Al)₂O₃) Silicon dioxide (SiO)₂) The iso-scattering elements are added to the polymer matrix to increase the diffusivity of various Nd and F compounds in the optical component. Three variables (e.g., TiO2, NdF3, and Nd in the above examples₂O₃Weight loading) may allow for the creation of a variety of specialized optical components to achieve a desired spectrum and distribution.

Further, according to an embodiment of the invention, the at least one compound (or more than one compound) may comprise elements of neodymium (Nd) and fluorine (F), and optionally one or more other elements. Typically, such compounds contain Nd³⁺Ions and F ions. For the purposes of the present invention, the expression "Nd-F compound" is to be interpreted broadly as including the inclusion of neodymium and fluoride and optionally other elementsA compound of the formula (I).

According to another embodiment, the component may comprise a composite/encapsulation layer on the surface of an led (oled) chip, such that various compounds including Nd and F disclosed herein may be blended (dispersed) in the encapsulation layer, e.g. together with phosphors, to achieve a favorable visible light absorption profile. The composite/encapsulation layer may be formed using low temperature glass, polymers (e.g., polycarbonate), polymer precursors, siloxane (polymer) or siloxane epoxy resins or precursors (precursor), and the like.

According to another embodiment, the optical component may be a transparent, semi-transparent reflective or semi-transmissive (partially reflective and transmissive) substrate, and the coating on the surface of the substrate contains various Nd and F components as described herein, which may impart a color filtering effect on the visible light produced by the LED module as it passes through the optical component, e.g., filtering visible light in the yellow wavelength range (e.g., wavelengths from about 560nm to about 600nm) to provide a desired spectrum.

Further, the transparent or translucent substrate of the optical component may be a diffuser, such as a bulb, a lens and an envelope surrounding the at least one LED chip. Further, the substrate may be a reflective substrate, and the LED chip may be disposed outside the substrate. A multi-compound coating (comprising Nd and F multi-compounds as described herein) can be disposed on the surface of the substrate, and the thickness of the coating should be sufficient to achieve a color filtering effect. The thickness may typically be in the range of 50nm to 1000 μm, preferably between 100nm and 500 μm.

The resulting devices can exhibit improvements in optical parameters through filtering using Nd and Nd-F compounds/materials with intrinsic absorption in the visible region between about 530nm and 600nm to enhance CSI (color saturation index), CRI (color rendering index), R9 (color rendering value), rendering (lighting preference index, LPI), and the like. R9 is defined as one of the 6 saturated test colors that are not used in the calculation of CRI. "degrees of visualization" is a LPI version based parameter of emitted light, described in co-pending, commonly owned international application PCT/US2014/054868 (published as WO2015/035425 on 12/3/2015) filed on 9/2014, and incorporated herein by reference in relevant parts.

In one embodiment, at least one of the plurality of compounds described herein can comprise Nd³⁺Ions and F-ions, and may be Nd-F compounds or Nd-X-F compounds. As used herein, "Nd-F compound" should be broadly construed to include compounds comprising neodymium and fluoride, and optionally other elements. Such neodymium and fluoride containing compounds may comprise neodymium fluoride or neodymium oxyfluoride (e.g., NdO)_xF_yWherein 2x + y is 3, e.g. Nd₄O₃F₆) Or neodymium fluoride containing adventitious water and/or oxygen, or neodymium oxyfluoride (e.g., Nd (OH))_aF_bWhere a + b ═ 3), or a variety of other compounds containing neodymium and fluoride, as will become apparent from the description below.

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

As noted above, one component/optical component may be a polymeric substrate (e.g., siloxane, polycarbonate, etc.) that contains, for example, two compounds Nd₂O₃And NdF₃. FIG. 2 is Nd, represented by curve 22₂O₃(1.0% in 1.3mm thick siloxane having a refractive index of 1.54) and NdF represented by Curve 20₃(2.9% in 1.3mm thick silicone with refractive index of 1.54) in the visible spectrum. It can be seen that the various materials share many similar absorption characteristics, particularly in the yellow (e.g., yellow)About 570nm to about 600 nm). The different absorption peaks shown in fig. 2 drive each component (Nd) in the color space₂O₃And NdF₃) As further shown in fig. 3. By combining these two compounds, a single Nd compound or neodymium glass (SiO) can be obtained₂Nd in (1)₂O₃) Color points cannot be obtained.

In use, the LED chip/die may be encapsulated with an encapsulant (e.g., silicone, epoxy, acrylic, etc.); the sealant may include Nd₂O₃And NdF₃Materials or Nd and F-based compounds as generally described herein, such as Nd in siloxane₂O₃And NdF₃Can be deposited directly on the LED chip or on an array of LED chips (e.g., chip-on-board array, COB array), as further detailed herein.

FIG. 3 is a color space diagram showing Nd incorporated into an optical component (e.g., siloxane or polycarbonate) and deposited on a standard LED package (e.g., 80CRI with 3000K CCT)₂O₃And NdF₃How the compounds can be bound by Nd respectively₂O₃And NdF₃The spectral absorption of the compounds defines

vectors

30 and 32 that shift the color point of the light source.

As is clear from the graph in fig. 3, by changing Nd₂O₃And NdF₃Relative amount of compound, i.e. along each Nd₂P₃And NdF₃The spectral absorption of the

compounds defining vectors

30 and 32 shifts the color point of the emitter, and the system can theoretically allow any color point in the triangle ABC produced by the standard 3000 KLED. However, since large energy losses due to high filtering are undesirable, the system can be practically limited to smaller regions 34, such as 12 macadam ellipses, or some other region size chosen arbitrarily based on the application and end user's desire to sacrifice LPW (lumens per watt) to achieve color points that are very far from the starting color. Area 34 is defined by lines BD, BE and curve 36. Any actual color point in region 34 may be in Nd₂O₃And NdF₃Wide range of relative amounts and expansions of compoundsThe implementation of the dispersion level allows to apply a given color point in different LED systems requiring different beam shaping characteristics of the optics. In contrast, adding neodymium glass (conventional method) only allows the color point to move to a single point 38 (or along a vector if the thickness of the glass changes). Fig. 4a, 4b, and 5 illustrate further examples for practicing embodiments disclosed herein.

FIG. 4a is a graph of varying amounts of Nd contained in a siloxane tape, according to one embodiment of the present invention₂O₃And NdF₃An exemplary plot of transmission in the visible spectrum of the neodymium compound mixture of (1). Curve 42a corresponds to a curve containing 4% NdF₃And 1% of Nd₂O₃1.3mm thick silicone tape, curve 44a corresponding to a silicone tape containing 5% NdF₃And 0.5% Nd₂O₃1.3mm thick silicone tape, curve 46a corresponding to a silicone tape containing 3% NdF₃And 0.5% Nd₂O₃1.3mm thick silicone tape, curve 48a corresponding to a silicone tape containing 3.5% NdF₃And 1.8% of Nd₂O₃1.3mm thick silicone tape.

Fig. 4b is a graph of simulated emissions of a lamp (e.g., an LED lamp) in the visible spectrum using filters with various Nd compound mixtures shown in fig. 4a, according to an embodiment of the invention. In FIG. 4b, curve 42b is for a sample having a composition containing 4% NdF₃And 1% of Nd₂O₃A simulated LED lamp with 1.3mm thick silicone tape, curve 44b for a lamp with a coating containing 5% NdF₃And 0.5% Nd₂O₃A simulated LED lamp with 1.3mm thick silicone tape, curve 46b for a lamp with a coating containing 3% NdF₃And 0.5% Nd₂O₃A simulated LED lamp with 1.3mm thick silicone tape, curve 48b for a lamp with a coating containing 3.5% NdF₃And 1.8% Nd₂O₃1.3mm thick silicone tape.

Fig. 5 is a color space diagram comparing the color point of a standard 3000K LED lamp with the color points of LED lamps comprising filters with various Nd compound mixtures shown in fig. 4a and 4b, respectively, according to an embodiment of the present invention. In fig. 5, color point 52 is for a color having a composition containing 4% NdF₃And 1% of Nd₂O₃1.3mm thick silicone tape, color point 54 for a simulated LED lamp having a coating containing 5% NdF₃And 0.5% Nd₂O₃1.3mm thick silicone tape, color point 56 for a simulated LED lamp having a coating containing 3% NdF₃And 0.5% Nd₂O₃1.3mm thick silicone tape, color point 58 for a simulated LED lamp having a coating containing 3.5% NdF₃And 1.8% Nd₂O₃1.3mm thick silicone tape.

FIGS. 4a, 4b and 5 show the NdF modification in the filter member of a (LED) lamp₃And Nd₂O₃Can change the color temperature of the lamp and change its emission spectrum (e.g. absorption peaks around the wavelength range of 570-600 nm) to provide a desired lamp spectrum (e.g. "whitening" of the light source) with a desired color temperature and a sufficient level of transmitted lumen power, so that other light parameters such as CSI, CRI, R9 and rendering can be further improved. "degrees of visualization" is a LPI version based parameter of emitted light, described in co-pending, commonly owned international application PCT/US2014/054868 (published as WO2015/035425 on 12/3/2015) filed on 9/2014, and incorporated herein by reference in relevant parts.

In another embodiment, a corresponding relative amount of a plurality of Nd and F compounds may be blended into an encapsulant material along with one or more luminescent materials (e.g., phosphors). For example, corresponding relative amounts of Nd and F various compounds may be blended with the yellow-green phosphor and/or the red phosphor. For example, a plurality of Nd and F compounds may be mixed with Ce-doped YAG phosphor and/or conventional red nitride phosphor (e.g., Eu²⁺Doped CaAlSiN red phosphor). In another example, Nd and F multiple compounds can be blended with YAG: Ce phosphor and red nitride phosphor in silicone, encapsulating a blue/ultraviolet emitting LED.

Fig. 6a-6d illustrate different non-limiting examples of LED-based

illumination devices

60a, 60b, 60c, and 60d, respectively, incorporating Nd and F multiple compounds, as described herein, and phosphors to achieve advantageous visible light absorption/generation characteristics, according to various embodiments of the present invention. In fig. 6a-6d, LED-based lighting devices 60a, 60db. 60c or 60d includes a dome 62, which dome 62 may 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 may be any semiconductor light source, in particular a blue or ultraviolet light source capable of producing white light when its emitted radiation is directed onto a phosphor. In particular, the semiconductor light source may be based on being generalized to In_iGa_jAl_kN, wherein I, j and k are integers each having a value of 1 or 0 (including, for example, InGaN, AlN, AlGaN, AlGaInN device structures), with emission wavelengths greater than about 200nm and less than about 550 nm. More specifically, the chip may be a near-UV or blue light emitting LED having a peak emission wavelength from about 400nm to about 500 nm. Even more particularly, the chip may 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.

According to one embodiment shown in fig. 6a, the polymer composite layer (encapsulant compound) 64a may include Nd and F multiple compounds, as described herein, blended with phosphors to impart advantageous visible light absorption/generation characteristics according to various embodiments described herein. The compound layer 64a may be disposed directly on the surface of the LED chip 65 and radiatively coupled to the chip. By "radiationally coupled" is meant that radiation from the LED chip is transmitted to the phosphor, and the phosphor emits radiation at a different wavelength. In particular embodiments, the LED chip 65 may be a blue LED, and the polymer composite layer may include a blend of a corresponding relative amount of a plurality of 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 Nd and F various compounds. Thus, the LED chip 65 may be surrounded by the encapsulant material layer 64 a. The sealant material may be low temperature glass, a thermoplastic or thermoset polymer or resin, or a silicone or epoxy resin. The LED chip 65 and the layer of encapsulant material 64a may be encapsulated within a housing (bounded by the dome 62). Alternatively, the LED device 60a may be packaged onlyIncluding sealant layer 64a and not outer housing/dome 62. Furthermore, as described herein, scattering particles may be embedded in the encapsulant material to increase the diffusivity of the Nd and F multiple compounds. The scattering particles may be, for example, alumina (Al)₂O₃) Silicon dioxide (SiO)₂) Or titanium dioxide (TiO)₂). Furthermore, the scattering particles may effectively scatter the directional light emitted from the LED chip, preferably with a negligible amount of absorption.

To form a polymer composite layer containing a corresponding relative amount of a plurality of Nd and F compounds described herein on the surface of an LED chip, the particles can be dispersed in a polymer or polymer precursor, particularly a siloxane, polycarbonate, siloxane epoxy, or a precursor thereof. Such materials are well known for LED packages. The dispersed mixture may be coated on the chip by any suitable process, for example using injection molding (or cast and extruded optics or similar techniques), and the particles having the greater density or size, or both, preferentially settle in the region near the LED chip, forming a layer having a graded composition. Sedimentation may occur during coating or curing of the polymer or precursor, and may be facilitated by centrifugation processes known in the art. It should also be noted that the dispersion parameters of the phosphor and the Nd and F multiple compounds, including, for example, particle density and particle size and process parameters, may be selected to provide a phosphor material that is closer to the LED chip 65 than the Nd and F multiple compounds so as to provide proper filtering of the light generated by the phosphor component by the Nd and F multiple compounds.

In an alternative exemplary embodiment shown in fig. 6b, the phosphor layer 64b may be a conventionally fabricated encapsulant layer, and a separate encapsulant layer 68b having Nd and F multiple compounds may be deposited on top of the phosphor layer 64b, for example: suitable conventional deposition/particle dispersion techniques are used in the polymer or polymer precursor.

In another exemplary embodiment shown in fig. 6c, a composite layer 68c containing multiple compounds of Nd and F may be coated on the outer surface of the dome (shell) 62. The properties of the coating layer 68b are similar to those of the sealant layer 68b having Nd and F compounds in fig. 6 b. Alternatively, coating 68c in fig. 6c may be deposited on the inner surface of dome 62. Further implementation details regarding the coating of the dome/substrate will be discussed with reference to fig. 7-10. Note that dome 62 itself may be transparent or translucent.

In yet another exemplary embodiment, as shown in fig. 6d, dome (shell) 62 may be used to deposit a plurality of Nd and F compound composite layers/coatings 68d on the outer surface of dome 62 and phosphor coating 64d on the inner surface of dome 62. It should also be noted that this method may be varied. For example, both

coatings

64d and 68d may be deposited on one surface (outer or inner) of dome 62, with phosphor coating 64d being closer to LED chip 65 than coating 68 d. In addition,

coatings

64d and 68d (when deposited on one surface of dome 62) may be combined in one layer, similar to sealant compound layer 64a in fig. 6 a. Note that dome 62 itself may be transparent, translucent, or semi-transmissive to achieve different variations of the example shown in fig. 6 d.

The following are a few non-limiting examples of LED-based illumination devices that use coatings containing Nd and F multiple compounds described herein that result in the desired color filter effect.

Fig. 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 capability. As shown in fig. 7, the LED lamp 70 includes a bulb 72, a connector 74, and a base 76 between the bulb 72 and the connector 74, and a coating 78 on an outer surface of the bulb 72. Coating 78 includes a plurality of compounds Nd and F as described herein. In other embodiments, the bulb 72 may be replaced by other transparent or translucent substrates. Alternatively, the coating 78 may be applied to the inner surface of the bulb 72, which may be transparent or translucent.

Fig. 8 is an LED-based lighting device 80 according to another embodiment of the present invention. As shown in fig. 8, the LED based lighting device is a pendant lamp 80 (LED chip not shown). The pendant 80 includes a hemispherical base 82 and a coating 88 comprising a plurality of compounds Nd and F as described herein; a coating 88 is on the interior surface of the hemispherical base 82. Alternatively, the coating 88 may be applied to the outer surface of the hemispherical substrate 82, which may be transparent or translucent.

Fig. 9 is an LED-based lighting device according to another embodiment of the present invention. As shown in fig. 9, the LED-based illumination device is a lens 90, and the lens 90 includes a flat substrate 92. In this embodiment, the flat substrate 92 includes a coating of a plurality of compounds Nd and F (not shown) on its outer surface.

Fig. 10 is an LED-based lighting device 100 according to another embodiment of 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 certain embodiments, the reflective substrate 106 includes a coating (not shown) of Nd and F multiple compounds on its outer surface to provide the desired filtering. In fig. 10, the dome (102) may be composed of a diffusing material, such 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 high the diffusivity of 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 may be constructed of a broadband semi-reflective material to provide the same function.

The coating materials described herein, including compounds containing Nd3+ ions and F ions, may have little optical scattering (diffusion) effect; or alternatively, may cause substantial optical scattering on light passing therethrough. To increase the scattering angle, the coating may comprise discrete particles of organic or inorganic material. Alternatively, the organic or inorganic material may consist of discrete particles of the Nd and F multiple compounds described herein alone, and/or a mixture of discrete particles of the Nd and F multiple compounds and particles formed of at least one other different material.

In one embodiment, a suitable particle size for the organic or inorganic material may be from about 1nm to about 10 μm. For the LED lamp 70 shown in fig. 7, to maximize the scattering angle to enable omnidirectional illumination by the LED lamp 70, the particle size may be selected to be much less than 300nm to maximize the efficiency of rayleigh scattering.

While not intending to be limiting, the Nd and F multi-compound coatings may be applied by, for example, spraying, roll coating, meniscus (meniscus) or dipping, stamping, screen coating, dispensing (spreading), roll coating, brushing, bonding, electrostatic coating, or any other method that can provide a coating of uniform thickness. Three non-limiting examples of how to provide coatings of Nd and F multiple compounds on a substrate will be described below.

In one embodiment, as shown in FIG. 7, coating 37 may be applied to bulb 72 by a bonding process. 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 binder may include epoxy resin, silicone resin binder, acrylic resin, and the like. The inorganic binder may include silicate inorganic binders, sulfate binders, phosphate binders, oxide binders, borate binders, and the like.

In another embodiment, as shown in FIG. 7, the coating 78 may be applied to the outer surface of the bulb 72 by a spray coating process. First, a liquid mixture is formed which contains, for example, a corresponding relative amount of Nd₂O₃And NdF₃Compound, silica, dispersant such as DISPEX a40, water and optionally TiO₂Or Al₂O₃. Subsequently, the formed liquid mixture is sprayed onto the bulb 72. Finally, the bulb 72 is cured to obtain the coated LED lamp 70.

In one embodiment, as shown in FIG. 7, the coating 78 may be applied to the outer surface of the bulb 72 by an electrostatic coating process. First, a mixture of, for example, a corresponding relative amount of Nd is prepared₂O₃And NdF₃Compound, SiO₂And Al₂O₃Charged powder of composition. The powder is then coated onto the oppositely charged bulb 72.

In another embodiment of the present invention, both the spray coating method and the electrostatic coating method may use materials that do not contain organic solvents or organic compounds, which may extend the lifetime of the LED lighting device and avoid discoloration that is typically caused by sulfonation.

In another embodiment, to promote refraction of light to obtain a white reflective appearance, the coating may further include additives having higher refractive indices relative to the plurality of Nd and F compounds. The additive may be selected from at least one of metal oxides or non-metal oxides, e.g. TiO₂、SiO₂And Al₂O₃。

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," and the like, as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Furthermore, the terms "a" and "an" do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms "connected" and "coupled" are not restricted to physical or mechanical connections or couplings, and can include electrical and optical connections or couplings, whether direct or indirect.

Furthermore, the skilled person will recognize the interchangeability of various features from different embodiments. Those of ordinary skill in the art may 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.

In describing alternative embodiments of the claimed apparatus, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. It is therefore to be understood that each specific element includes all technical equivalents which operate in a similar manner to accomplish a similar function.

It is to 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 following claims.

It should be noted that the various non-limiting embodiments described and claimed herein can be used alone, combined, or selectively combined for specific applications.

Furthermore, some of the various features of the non-limiting embodiments described above could be used to advantage without the corresponding use of other described features. Accordingly, 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. An apparatus, comprising:

at least one Light Emitting Diode (LED) module configured to generate visible light;

a phosphor; and

at least one component comprising two or more compounds,

wherein one compound of the two or more compounds comprises Nd₂O₃；

Wherein at least one additional compound of the two or more compounds comprises a compound having the formula NdO_xF_yWherein 2x + y is 3; or of the formula Nd (OH)_aF_bThe neodymium oxyfluoride of (1), wherein a + b is 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;

the at least one component comprises neodymium oxyfluoride or neodymium oxyfluoride in an amount greater than Nd₂O₃In an amount of said neodymium oxyfluoride having the formula NdO_xF_yWherein 2x + y is 3; or said neodymium oxyhydroxide fluoride has the formula Nd (OH)_aF_bWherein a + b is 3; and

wherein the at least one component comprises a material selected fromFrom TiO₂、SiO₂And Al₂O₃An additive of the group to increase the diffusivity of the two or more compounds in the at least one component.

2. The apparatus of claim 1, wherein the color of the desired spectrum in the color space varies within a predetermined region in the color space defined at least by absorption vectors of the two or more compounds.

3. The apparatus of claim 2, wherein the predetermined region in the color space is limited to about 12 macadam ellipses.

4. The apparatus of claim 1, wherein the two or more compounds comprise Nd³⁺Ions and F^-Ions.

5. The apparatus of claim 1, wherein the at least one component is an encapsulation layer deposited on top of the at least one LED module.

6. The apparatus of claim 5, wherein the encapsulation layer is a low temperature glass, a polymer precursor, a polycarbonate, a thermoplastic or thermoset polymer or resin, a siloxane, or a siloxane epoxy.

7. The apparatus of claim 1, wherein the at least one component is 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.

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

9. The apparatus of claim 1, wherein the coating has a thickness in a range from about 50 nanometers to about 1000 micrometers.

10. The apparatus of claim 9, 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 the group consisting of at least TiO₂、SiO₂And Al₂O₃Metal oxides and non-metal oxides of (a).

11. The apparatus of claim 9, wherein the coating is disposed on an inner surface of the substrate.

12. The apparatus of claim 9, 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.

13. The apparatus of claim 1, wherein the apparatus comprises an integrated circuit containing a plurality of LED modules having a corresponding plurality of components.

14. The apparatus of claim 1, wherein the at least one component is deposited using injection molding.