Source: https://patents.google.com/patent/WO2007139781A2/en
Timestamp: 2019-04-23 08:16:23
Document Index: 652209278

Matched Legal Cases: ['Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60']

WO2007139781A2 - Lighting device - Google Patents
WO2007139781A2
WO2007139781A2 PCT/US2007/012159 US2007012159W WO2007139781A2 WO 2007139781 A2 WO2007139781 A2 WO 2007139781A2 US 2007012159 W US2007012159 W US 2007012159W WO 2007139781 A2 WO2007139781 A2 WO 2007139781A2
PCT/US2007/012159
WO2007139781A3 (en
2006-05-23 Priority to US60/802,709 priority
2006-05-26 Priority to US60/808,702 priority
2007-05-22 Application filed by Cree Led Lighting Solutions, Inc. filed Critical Cree Led Lighting Solutions, Inc.
2007-12-06 Publication of WO2007139781A2 publication Critical patent/WO2007139781A2/en
2008-05-15 Publication of WO2007139781A3 publication Critical patent/WO2007139781A3/en
Field of the Invβntioa
A large proportion (some estimates are as high as twenty-five percent) of the electricity generated in the United States each year goes to lighting. Accordingly, there is an ongoing need to provide lighting which is more energy-efficient. It is well-known that incandescent light bulbs are very energy-inefficient light sources — about ninety percent of the electricity they consume is released as heat rather than light. Fluorescent light bulbs are more efficient than incandescent light bulbs (by a factor of about 10) but are still less efficient as compared to solid state light emitters, such as light emitting diodes.
Color reproduction is typically measured using the Color Rendering Index (CRI Ra). CRI Ra is a modified average of the relative measurements of how the color rendition of an illumination system compares to that of a reference radiator when illuminating eight reference colors, i.e., it is a relative measure of the shift in surface color of an object when lit by a particular lamp. The CRI Ra equals 100 if the color coordinates of a set of test colors being illuminated by the illuminatipn system are the same as the coordinates of the same test colors being irradiated by the reference radiator. Daylight has a high CRI (Ra of approximately 100), with incandescent bulbs also being relatively close (Ra greater than 95), and fluorescent lighting being less accurate (typical Ra of 70-80). Certain, types of specialized lighting have very low CRI (e.g., mercury vapor or sodium lamps, have Ra as low as about 40 or even lower).
Accordingly, for these and other reasons, efforts have been ongoing to develop ways by which light emitting diodes and other solid state light emitters can be used in place of incandescent lights, fluorescent lights and other light-generating devices in a wide variety of applications, hi addition, where light emitting diodes (or other solid state light emitters) are already being used, efforts are ongoing to provide light emitting diodes (or other solid state light emitters) which are improved, e.g., with respect to energy efficiency, color rendering index (CRI Ra), contrast, efficacy (lm/W), cost, and/or duration of service.
More specifically, light emitting diodes are semiconducting devices that emit light (ultraviolet, visible, or infrared) when a potential difference is applied across a p-n junction structure. There are a number of well-known ways to make light emitting diodes and many associated structures, and the present invention can employ any such devices. By way of example, Chapters 12-14 of Sze, Physics of Semiconductor Devices, (2d Ed. 1981) and Chapter 7 of Sze, Modern Semiconductor Device Physics (1998) describe a variety of photonic devices, including light emitting, diodes.
The expression "light emitting diode" is used herein to refer to the basic semiconductor diode structure (i.e., the chip). The commonly recognized and commercially available "LED" that is sold (for example) in electronics stores typically represents a "packaged" device made up of a number of parts. These packaged devices typically include a semiconductor based light emitting diode such as (but not limited to) those described in U.S. Pat. Nos. 4,918,487; 5,631,190; and 5,912,477, various wire connections, and a package that encapsulates the light emitting diode.
Aspects related to the present invention can be represented on either the 1931 CIE (Commission International de I'Eclairage) Chromaticity Diagram or the 1976 CIE Chromaticity Diagram. Fig. 1 shows the 1931 CIE Chromaticity Diagram. Fig. 2 shows the 1976 Chromaticity Diagram. Fig. 3 shows an enlarged portion of the 1976 Chromaticity Diagram, in order to show the blackbody locus in more detail. Persons of skill in the art are familiar with these diagrams, and these diagrams are readily available (e.g., by searching "CDE Chromaticity Diagram" on the internet).
Since similar distances on the 1976 Diagram represent similar perceived differences in color, deviation from a point on the 1976 Diagram can be expressed in terms of the coordinates, u' and v', e.g., distance from the point = (Δu'2 ■+■ Δv'2)'Λ, and the hues defined by a locus of points which are each a common distance from a specified hue consist of hues which would each be perceived as differing from the specified hue to a common extent.
The chromaticity coordinates and the CEE chromaticity diagrams illustrated in Figs. 1- 3 are explained in detail in a number of books and other publications, such as pages 98-107 of K. H. Butler, "Fluorescent Lamp Phosphors" (The Pennsylvania State University Press 1980) and pages 109-110 of G. Blasse et al., "Luminescent Materials" (Springer-Verlag 1994), both incorporated hereinby reference.
The chromaticity coordinates (i.e., color points) that lie along the blackbody locus obey Planck's equation: E(λ)=A λ"5/(e(B/T)-l), where E is the emission intensity, λ is the emission wavelength, T the color temperature of the blackbody and A and B are constants. Color coordinates that lie on or near the blackbody locus yield pleasing white light to a human observer. The 1976 CEE Diagram includes temperature listings along the blackbody locus. These temperature listings show the color path of a blackbody radiator that is caused to increase to such temperatures. As a heated object becomes incandescent, it first glows reddish, then yellowish, then white, and finally blueish. This occurs because the wavelength associated with the peak radiation of the blackbody radiator becomes progressively shorter with increased temperature, consistent with the Wien Displacement Law. Illuminants which produce light which is on or near the blackbody locus can thus be described in terms of their color temperature.
Also depicted on the 1976 CIE Diagram are designations A, B, C5 D and E, which refer to light produced by several standard illuminants correspondingly identified as illuminants A, B, C, D and E, respectively.
For example, U.S. Patent No. 6,963,166 (Yano '166) discloses that a conventional light emitting diode lamp includes a light emitting diode chip, a bullet-shaped transparent housing to cover the light emitting diode chip, leads to supply current to the light emitting diode chip, and a cup reflector for reflecting the emission of the light emitting diode chip in a uniform direction, in which the light emitting diode chip is encapsulated with a first resin portion, which is further encapsulated with a second resin portion. According to Yano c 166, the first resin portion is obtained by filling the cup reflector with a resin material and curing it after the light emitting diode chip has been mounted onto the bottom of the cup reflector and then has had its cathode and anode electrodes electrically connected to the leads by way of wires. According to Yano '166, a phosphor is dispersed in the first resin portion so as to be excited with the light A that has been emitted from the light emitting diode chip, the excited phosphor produces fluorescence ("light B") that has a longer wavelength than the light A, a portion of the light A is transmitted through the first resin portion including the phosphor, and as a result, light C, as a mixture of the light A and light B3 is used as illumination.
As noted above, "white LED lamps" (i.e., lights which are perceived as being white or near-white) have been investigated as potential replacements for white incandescent lamps. A representative example of a white LED lamp includes a package of a blue light emitting diode chip, made of indium gallium nitride (InGaN) or gallium nitride (GaN), coated with a phosphor such as YAG. In such an LED lamp, the blue light emitting diode chip produces an emission with a wavelength of about 450 rim, and the phosphor produces yellow fluorescence with a peak wavelength of about 550 nm on receiving that emission. For instance, in some designs, white light emitting diode lamps are fabricated by forming a ceramic phosphor layer on the output surface of a blue light-emitting semiconductor light emitting diode. Part of the blue ray emitted from the light emitting diode chip passes through the phosphor, while part of the blue ray emitted from the light emitting diode chip is absorbed by the phosphor, which becomes excited and emits a yellow ray. The part of the blue light emitted by the light emitting diode which is transmitted through the phosphor is mixed with the yellow light emitted by the phosphor. The viewer perceives the mixture of blue and yellow light as white light.
In a second aspect of the present invention, there is provided a lighting device comprising at least one encapsulant region, at least one plural cavity element (having at least two optical cavities), and a plurality of solid state light emitters, at least one solid state light emitter being present in each of at least two of the optical cavities. In this aspect of the present invention, at least a portion of the plural cavity element, with the solid state light emitters mounted on optical cavities of the plural cavity element, is surrounded by the encapsulant region, hi some embodiments according to this aspect of the invention, the plural cavity element is embedded in the encapsulant region. hi some embodiments according to the present invention, at least one broad spectrum light emitter (defined below) is provided in a first of the optical cavities and at least one narrow spectrum light emitter (defined below) is provided in a second of the optical cavities.
In some embodiments according to the present invention, the plural cavity element comprises a first surface, the first surface being substantially planar, the first surface having a surface area which is at least five times as large as a combined surface area of the solid state light emitters. In some such embodiments,- each of the optical cavities formed in the plural cavity element comprises a substantially planar mounting surface on which at least one of the solid state light emitters is mounted.
Fig. 3 shows an enlarged portion of the 1976 Ghromaticity Diagram, in order to show the blackbody locus in detail.
In some embodiments of the present invention, each of the cavities in a plural cavity element has substantially the same shape. As used herein, the term "substantially," e.g., in the expressions "substantially planar", "substantially flat", "substantially coplanar", "substantially the same shape", "substantially transparent", means at least about 90 % correspondence with the feature recited, e.g.: the expressions "substantially planar" and "substantially flat", as used herein, mean that at least 90% of the points in the surface which is characterized as being substantially flat are located on one of or between a pair of planes which are parallel and which are spaced from each other by a distance of not more than 5% of the largest dimension of the surface; the expression "substantially coplanar", as used herein, means that at least 90% of the points in each of the surfaces which are characterized as being substantially coplanar are located on one of or between a pair of planes which are parallel and which are spaced from each other by a distance of not more than 5% of the largest dimension of the surface; the expression "substantially the same shape", as used herein, means that angles and radii of curvature defined by respective surfaces on the respective items which are characterized as being substantially the same shape differ by not more than 5 %; the expression "substantially transparent", as used herein, means that the structure which is characterized as being substantially transparent allows passage of at least 90 % of the light having a wavelength within the range emitted by the solid state light emitter.
In some embodiments of the present invention, at least one (and, in some embodiments, all) of the optical cavities formed in the plural cavity element comprises a substantially planar mounting surface on which at least one of the solid state light emitters is mounted. In some embodiments of the present invention, each optical cavity in the plural cavity element comprises a substantially flat mounting surface, and each of the mounting surfaces are substantially coplanar.
In some embodiments according to the present invention, at least one of the optical cavities can have mounted therein plural solid state light emitters of a single color or of plural colors, hi some such embodiments, at least one of the optical cavities can have mounted therein two or more saturated solid state light emitters of a single color or of plural colors.
As noted above, in some embodiments according to the present invention, at least one broad spectrum light emitter is provided in a first of the optical cavities and at least one narrow spectrum light emitter is provided in a second of the optical cavities, hi some such embodiments, there are provided a plurality of optical cavities in which at least one broad spectrum light emitter (wherein the respective broad spectrum light emitters in the different optical cavities are all similar, are all different or are any possible combination of similar and different) is provided and a plurality of optical cavities in which at least one narrow spectrum light emitter (wherein the respective narrow spectrum light emitters in the different optical cavities are all similar, are all different or are any possible combination of similar and different) is provided (optionally, there may further be other optical cavities in which other light emitters are provided).
In some embodiments of the second aspect of the present invention, the light exiting the respective solid state light emitters (and any lumiphors) contained in an encapsulant region is approximately 80 % mixed by the time the light exits the encapsulant region, and such light is nearly completely mixed 5 cm away from the surface of the encapsulant region.
Specific examples of combinations of light emitters and/or lumiphors are described in U.S. Patent Application No. 60/752,555, filed December 2.1, 2005, entitled "Lighting Device and Lighting Method" (inventors: Antony Paul Van de Ven and Gerald H. Negley), the entirety of which is hereby incorporated by reference).
(a) U.S. Patent Application No. 60/752,555, filed December 21, 2005, entitled "Lighting Device and Lighting Method" (inventors: Antony Paul Van de Ven and Gerald H. Negley), the entirety of which is hereby incorporated by reference,
(b) U.S . Patent Application No. 60/793,524, filed April 20, 2006, entitled "Lighting Device" (inventors: Antony Paul Van de Ven and Gerald H. Negley), the entirety of which is hereby incorporated by reference, and
(c) U.S. Patent Application No. 60/793,518, filed April 20, 2006, entitled "Lighting Device" (inventors: Antony Paul Van de Ven and Gerald H. Negley), the entirety of which is hereby incorporated by reference.
.Included among such combinations of light emitters and/or lumiphors are:
(1) a combination including: a first group of light emitting diodes; a first group of lumiphors; and a second group of light emitting diodes; wherein: each of the first group of light emitting diodes, if illuminated, would emit light having a peak wavelength in the range of from 430 nm to 480 run; each of the first group of lumiphors, if excited, would emit light having a dominant wavelength in the range of from about 555 nm to about 585 nm; and each of the second group of light emitting diodes, if illuminated, would emit light having a dominant wavelength in the range of from 600 nm to 630 nm;
(2) a combination including: a first group of light emitting diodes; a first group of lumiphors; a second group of light emitting diodes; a second group of lumiphors; and a third group of light emitting diodes; wherein: each of the first group of light emitting diodes and each of the second group of light emitting diodes, if illuminated, would emit light having a peak wavelength in the range
each of the first group of lumiphors and each of the second group of lumiphors, if excited, would emit light having a dominant wavelength in the range of from about 555 nm to about 585 nm; and if each of the first group of light emitting diodes is illuminated and each of the first group of lumiphors is excited, a mixture of light emitted from the first group of light emitting diodes and the first group of lumiphors would, in the absence of any additional light, have a first group mixed illumination corresponding to a first point on a 1931 CIE Chromaticity Diagram, the first point having a first correlated color temperature; if each of the second group of light emitting diodes is illuminated and each of the second group of lumiphors is excited, a mixture of light emitted from the second group of light emitting diodes and the second group of lumiphors would, in the absence of any additional light, have a second group mixed illumination corresponding to a second point on a 1931 CIE Chromaticity Diagram, the second point has a second correlated color temperature, the first correlated color temperature differs from the second correlated color temperature by at least 500K; and each of the second group of light emitting diodes, if illuminated,- would emit light having a dominant wavelength in the range of from 600 nm to 630 nm;
(3) a combination including: a first group of light emitting diodes; a first group of lumiphors; and a second group of light emitting diodes; wherein: each of the first group, of light emitting diodes, if illuminated, would emit light having a peak wavelength in the range of from 430 nm to 480 nm; each of the first group of lumiphors, if excited, would emit light having a dominant wavelength in the range of from about 555 nm to about 585 nm; each of the second group of light emitting diodes, if illuminated, would emit light having a dominant wavelength in the range of from 600 nm to 630 nm; and if each of the first group of light emitting diodes is illuminated and each of the first group of lumiphors is excited, a mixture of light emitted from the first group of light emitting diodes and the first group of lumiphors would, in the absence of any additional light, have a first group mixed illumination having x, y color coordinates which are within an area on a 1931 CIE Chromaticity Diagram enclosed by first, second, third, fourth and fifth line segments, the first line segment connecting a first point to a second point, the second line segment connecting the second point to a third point, the third line segment connecting the third point to a fourth point, the fourth line segment connecting the fourth point to a fifth point, and the fifth line segment connecting the fifth point to the first point, the first point having x, y coordinates of 0.32, 0.40, the second point having x, y coordinates of 0.36, 0.48, the third point having x, y coordinates of 0.43, 0.45, the fourth point having x, y coordinates of 0.42, 0.42, and the fifth point having x, y coordinates of 0.36, 0.38; and
(4) a combination including: a first group of light emitting diodes; a first group of lumiphors; a second group of light emitting diodes; a second group of lumiphors; and a third group of light emitting diodes; wherein: each of the first group of light emitting diodes and each of the second group of light emitting diodes, if illuminated, would emit light having a peak wavelength in the range of from 430 nm to 480 nm; each of the first group of lumiphors and each of the second group of lumiphors, if excited, would emit light having a dominant wavelength in the range of from about 555 nm to about 585 nm; and if each of the first group of light emitting diodes is illuminated and each of the first group of lumiphors is excited, a mixture of light emitted from the first group of light emitting diodes and the first group of lumiphors would have a first group mixed illumination corresponding to a first point on a 1931 CEE Chromaticity Diagram, the first point having a first correlated color temperature; if each of the second group of light emitting diodes is illuminated and each of the second group of lumiphors is excited, a mixture of light emitted from the second group of light emitting diodes and the second group of lumiphors would have a second group mixed illumination corresponding to a second point on a 1931 CIE Chromaticity Diagram, the second point has a second correlated color temperature, the first correlated color temperature differs from the second correlated color temperature by at least 500K; each of the third group of light emitting diodes, if illuminated, would emit light having a dominant wavelength in the range of from 600 nm to 630 nm; and if each of the first group of light emitting diodes is illuminated, each of the first group of lumiphors is excited, each of the second group of light emitting diodes is excited and each of the second group of lumiphors is excited, a mixture of light emitted from the first group of light emitting diodes, the first group of lumiphors, the second group of light . emitting diodes and the second group of lumiphors, in the absence of any other light, would have a first group-second group mixed illumination which, in the absence of any other light, would have x, y color coordinates which are within an area on a 1931 CIE Chromaticity Diagram enclosed by first, second, third, fourth and fifth line segments, the first line segment connecting a first point to a second point, the second line segment connecting the second point to a third point, the third line segment connecting the third point to a fourth point, the fourth line segment connecting the fourth point to a fifth point, and the fifth line segment . connecting the fifth point to the first point, the first point having x, y coordinates of 0.32, 0.40, the second point having x, y coordinates of 0.36, 0.48, the third point having x, y coordinates of 0.43, 0.45, the fourth point having x, y coordinates of 0.42, 0.42, and the fifth point having x, y coordinates of 0.36, 0.38.
(1) a combination including: a first group of light emitting diodes; a first group of lumiphors; and' a second group of light emitting diodes; wherein: each of the first group of light emitting diodes, if illuminated, would emit light haying a peak wavelength in the range of from 430 run to 480 nm; each of the first group of lumiphors, if excited, would emit light having a dominant wavelength in the range of from about 555 nm to about 585 nm; and each of the second group of light emitting diodes, if illuminated, would emit light having a dominant wavelength in the range of from 610 nm to 630 nm;
(2) a combination including: a first group of light emitting diodes; a first group of lumiphors; a second group of light emitting diodes; a second group of lumiphors; and a third group of light emitting diodes; wherein: each of the first group of light emitting diodes and each of the second group of light emitting diodes, if illuminated, would emit light having a peak wavelength in the range of from 430 nm to 480 run; each of the first group of lumiphors and each of the second group of lumiphors, if excited, would emit light having a dominant wavelength in the range of from about 555 nm to about 585 nm; and if each of the first group of light emitting diodes is illuminated and each of the first group of lumiphors is excited, a mixture of light emitted from the first group of light emitting diodes and the first group of lumiphors -would, in the absence of any additional light, have a first group mixed illumination corresponding to a first point on a 1931 CIE Chromaticity Diagram, the first point having a first correlated color temperature; if each of the second group of light emitting diodes is illuminated and each of the second group of lumiphors is excited, a mixture of light emitted from the second group of light emitting diodes and the second group of lumiphors would, in the absence of any additional light, have a second group mixed illumination corresponding to a second point on a 1931 CIE Chromaticity Diagram, the second point has a second correlated color temperature, the first correlated color temperature differs from the second correlated color temperature by at least 500K; and each of the second group of light emitting diodes, if illuminated, would emit light having a dominant wavelength in the range of from 610 nm to 630 nm;
(3) a combination including: a first group of light emitting diodes; a first group of lumiphors; a second group of light emitting diodes; and a third group of light emitting diodes, wherein: if each of the first group of light emitting diodes is illuminated and each of the first group of lumiphors is excited, a mixture of light emitted from the first group of light emitting diodes and the first group of lumiphors would, in the absence of any additional light, have a first group mixed illumination having x, y color coordinates which are within an area on a 1931 CIE Chromaticity Diagram enclosed by first, second, third and fourth line • ■ segments, the first line segment connecting a first point to a second point, the second line segment connecting the second point to a third point, the third line segment connecting the third point to a fourth point, and the fourth line segment connecting the fourth point to the first point, the first point having x, y coordinates of 0.30, 0.27, the second point having x, y coordinates of 0.30, 0.37, the third point having x, y coordinates of 0.34, 0.27, and the fourth point having x, y coordinates of 0.34, 0.37; each of the second group of light emitting diodes, if illuminated, would emit light having a dominant wavelength in the range of from 600 nm to 630 nm; and each of the third group of light emitting diodes, if illuminated, would emit light having a dominant wavelength in the range of from 490 nm to 510 nm;
(4) a combination including: a first group of light emitting diodes; a first group of lumiphors; a second group of light emitting diodes; and a third group of light emitting diodes, wherein: if each of the first group of light emitting diodes is illuminated and each of the first group of lumiphors is excited, a mixture of light emitted from the first group of light emitting diodes and the first group of lumiphors would, in the absence of any additional light, have a first group mixed illumination having x, y color coordinates which, are within an area on a 1931 CIE Chromaticity Diagram enclosed by first, secondj third and fourth line segments, the first line segment connecting a first point to a second point, the second line segment connecting the second point to a third point, the third line segment connecting the third point to a fourth point, and the fourth line segment connecting the fourth point to the first point, the first point having x, y coordinates of 0.30, 0.27, the second point having x, y coordinates of 0.30, 0.37, the third point having x, y coordinates of 0.34, 0.27, and the fourth point having x, y coordinates of 0.34, 0.37; each of the second group of light emitting diodes, if illuminated, would emit light having a dominant wavelength in the range of from 600 nm to 630 nm; and each of the third group of light emitting diodes, if illuminated, would emit light having a dominant wavelength in the range of from 520 nm to 550 nm;
(5) a combination including: a first group of light emitting diodes; a first group of lumiphors; a second group of light emitting diodes; and a third group of light emitting diodes wherein: each of the first group of light emitting diodes, if illuminated, would emit light having a peak wavelength in the range of from 430 nm to 480 nm; each of the first group of lumiphors, if excited, would emit light having a dominant wavelength in the range of from about 555 nm to about 5S5 nm; and each of the second group of light emitting diodes, if illuminated, would emit light having a dominant wavelength in the range of from 610 nm to 630 nm; each of the third group of light emitting diodes, if illuminated, would emit light having a peak wavelength in the range of from 430 nm to 480 nm;
(6) a combination including: a first group of light emitting diodes; a first group of lumiphors; a second group of light emitting diodes; a second group of lumiphors; a third group of light emitting diodes; and a fourth group of light emitting diodes; wherein: each of the first group of light emitting diodes and each of the second group of light emitting diodes, if illuminated, would emit light having a peak wavelength in the range of from 430 nm to 480 nm; each of the first group of lumiphors and each of the second group of lumiphors, if excited, would emit light having a dominant wavelength in the range of from about 555 nm to about 585 nm; and if each of the first group of light emitting diodes is illuminated and each of the first group of lumiphors is excited, a mixture of light emitted from the first group of light emitting diodes and the first group of lumiphors would, in the absence of any additional light, have a first group mixed illumination corresponding to a first point on a 1931 CIE Chromaticity Diagram, the first point having a first correlated color temperature; if each of the second group of light emitting diodes is illuminated and each of the second group of lumiphors is excited, a mixture of light emitted from the second group of light emitting diodes and the second group of lumiphors would, in the absence of any additional light, have a second group mixed illumination corresponding to a second point on a 1931 CIE Chromaticity Diagram, the second point has a second correlated color temperature, the first correlated color temperature differs from the second correlated color temperature by at least 500K; and each of the third group of light emitting diodes, if illuminated, would emit light having a dominant wavelength in the range of from 610 nm to 630 nm; each of the fourth group of light emitting diodes, if illuminated, would emit light having a peak wavelength in the range of from 430 nm to 480 nm;
As noted above, in some embodiments according to the present invention, the lighting device further comprises at least one lumiphor (i.e., luminescence region or luminescent element which comprises at least one luminescent material). The one or more luminescent materials, when provided, can be in any desired form and can be selected from among phosphors, scintillators, day glow tapes, inks which glow in the visible spectrum upon illumination with ultraviolet light, etc. The luminescent element can, if desired, be embedded in a resin (i.e., a polymeric matrix), such as a silicone material, an epoxy, a substantially transparent glass or a metal oxide material. The expression "lumiphor", as used herein, refers to any luminescent element, i.e., any element which includes a luminescent material, a variety of which are readily available and well-known to those skilled in the art.
Devices in which a lumiphor is provided can, if desired, further comprise one or more clear encapsulant (comprising, e.g., one or more silicone materials) positioned between the solid state light emitter (e.g., light emitting diode) and the lumiphor. The or each of the one or more lumiphors can, independently, further comprise any of a number of well-known additives, e.g., diffusers, scatterers, tints, etc.
One or more brightness enhancement films can optionally further be included in the lighting devices according to this aspect of the present invention. Such films are well-known in the art and are readily available. Brightness enhancement films (e.g., BEF films commercially available from 3M) are optional - when employed, they provide a more directional light source by limiting the acceptance angle. Light not "accepted" is recycled by the highly reflective light source enclosure. Preferably, the brightness enhancement films (which can optionally be replaced by one or more extraction films, such as by WFT), if employed, are optimized to limit the viewing angle of the emitted source and to increase the probability of extracting light on the first (or earliest possible) pass.
Representative examples of arrangements of lighting devices, schemes for mounting lighting devices, apparatus for supplying electricity to lighting devices, housings for lighting devices, fixtures for lighting devices and power supplies for lighting devices, all of which are suitable for the lighting devices of the present invention, are described in U.S. Patent Application No. 60/752,753, filed on December 21, 2005, entitled "Lighting Device" (inventors: Gerald H. Negley, Antony Paul Van de Ven and Neal Hunter), the entirety of which is hereby incorporated by reference, and in U.S. Patent Application No. 60/798,446, filed on May 5, 2006, entitled "Lighting Device" (inventor: Antony Paul Van de Ven and Neal Hunter) (attorney docket number 931_008), the entirety of which is hereby incorporated by reference.
The devices according to the present invention can further comprise one or more long- life cooling device (e.g., a fan with an extremely high lifetime). Such long-life cooling device(s) can comprise piezoelectric or magnetorestrictive materials (e.g., MR, GMR, and/or HMR materials) that move air as a "Chinese fan". In cooling the devices according to the present invention, typically only enough air to break the boundary layer is required to induce temperature drops of 10 to 15 degrees C. Hence, in such cases, strong 'breezes" or a large fluid flow rate (large CFM) are typically not required (thereby avoiding the need for conventional fans).
The devices according to the present invention can further comprise secondary optics to further change the projected nature of the emitted light. Such secondary optics are well- known to those skilled in the art, and so they do not need to be described in detail herein — any, such secondary optics can, if desired, be employed.
(4) a plural cavity element having at least one of a first type of optical cavity, at least one of a second type of optical cavity and at least one of a third type of optical cavity, the first type of optical cavity having mounted therein a blue light emitting diode with a yellow phosphor , the second type of optical cavity having mounted therein a blue light emitting diode, the third type of optical cavity having mounted therein a red light emitting diode;
(6) a plural cavity element having at least one of a first type of optical cavity, at least one of a second type of optical cavity and'at least one of a third type of optical cavity, the first type of optical cavity having mounted therein a light emitting diode and a green phosphor, the second type of optical cavity having mounted therein a red light emitting diode, the third type of optical cavity having mounted therein a blue light emitting diode;
(8) a plural cavity element having at least one of a first type of optical cavity, at least one of a second type of optical cavity and at least one of a third type of optical cavity, the first type of optical cavity having mounted therein a cyan light emitting diode, the second type of optical cavity having mounted therein an orange light emitting diode, the third type of optical cavity having mounted therein a "white" light emitting diode;
(9) a plural cavity element having at least one of a first type of optical cavity, at least one of a second type of optical cavity and at least one of a third type of optical cavity, the first type of optical cavity having mounted therein a cyan light emitting diode, the second type of optical cavity having mounted therein a red light emitting diode, the third type of optical cavity having mounted therein a "white" light emitting diode;
(11) a plural cavity element having at least one of a first type of optical cavity and at least one of a second type of optical cavity, the first type of optical cavity having mounted therein a cyan light emitting diode and a yellow phosphor, the second type of optical cavity having mounted therein a red light emitting diode; and (12) packaged devices including any of the above plural cavities (i.e., (1) - (11)) embedded in an encapsulant region.
1. A lighting device comprising: at least one plural cavity element, said plural cavity element having at least two optical cavities, each of said optical cavities comprising a concave region in said plural cavity element; and a plurality of solid state light emitters, at least one of said solid state light emitters being present in each of at least two of said optical cavities.
5. A lighting device as recited in claim 1, wherein said plural cavity element comprises a first side and a second side, said first side comprising a substantially planar first surface and a plurality of substantially flat mounting surfaces, at least one of said solid state light emitters being mounted on each of said mounting surfaces, each of said mounting surfaces being substantially coplanar, said first surface and said mounting surfaces together comprising not less than 75 % of a surface area of said first side of said plural cavity element. •
11. A lighting device comprising: at least one plural cavity element, said plural cavity element having at least two optical cavities, each of said optical cavities comprising a concave region in said plural cavity element; a plurality of solid state light emitters, at least one of said solid state light emitters being present in each of at least two of said optical cavities; and at least one encapsulant region, at least a portion of said plural cavity element being surrounded by said encapsulant region.
15. A lighting device as recited in claim 11 , wherein walls of each of said optical cavities are reflective.
18. A lighting device as recited in claim 11, wherein said plural cavity element comprises a first side and a second side, said first side comprising a substantially planar first surface and a plurality of substantially flat mounting surfaces, at least one of said solid state light emitters being mounted on each of said mounting surfaces, each of said mounting surfaces being substantially coplanar, said first surface and said mounting surfaces together comprising not less than 75 % of a surface area of said first side of said plural cavity element.
PCT/US2007/012159 2006-05-23 2007-05-22 Lighting device WO2007139781A2 (en)
US60/802,709 2006-05-23
US60/808,702 2006-05-26
EP07795158.0A EP2027412B1 (en) 2006-05-23 2007-05-22 Lighting device
JP2009512102A JP2009538532A (en) 2006-05-23 2007-05-22 Lighting device
WO2007139781A2 true WO2007139781A2 (en) 2007-12-06
WO2007139781A3 WO2007139781A3 (en) 2008-05-15
See also references of EP2027412A4
SZE: "Modern Semiconductor Device Physics", 1998, article "Chapters 7"
SZE: "Physics of Semiconductor Devices. 2nd ed.", 1981, article "Chapters 12-14"
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