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.
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)xFyWherein 2x + y is 3, e.g. Nd4O3F6) Or neodymium fluoride containing adventitious water and/or oxygen, or neodymium oxyfluoride (e.g., Nd (OH))aFbWhere 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 IniGajAlkN, 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.