JP2013521647A - Radiators with improved color rendering index through phosphor separation - Google Patents

Abstract

  Disclosed are LED packages, and LED lamps 340 and bulbs, arranged to minimize loss of CRI and efficiency resulting from overlap of conversion material emission and excitation spectra. In different devices with this overlapping conversion material, the present invention reduces the probability that light re-emitted from the first conversion material will hit the second conversion material and minimizes the risk of reabsorption. The conversion material is made into. In some embodiments, this risk is minimized by a different arrangement in which the two phosphors 342, 344 are separated from each other. In some embodiments, this separation results in less than 50% of the light re-emitted from one phosphor entering the phosphor, where there is a risk of re-absorption.

Description

  This application is based on US Provisional Patent Application No. 61 / 339,516 filed on March 3, 2010, US Provisional Patent Application No. 61 / 339,515 filed on March 3, 2010, September 2010. US Provisional Patent Application No. 61 / 386,437 filed on the 24th, US Provisional Application No. 61 / 424,665 filed on the 19th December 2010, US Provisional Application No. 61 / 424,665 filed on the 19th December 2010 61 / 424,670, US provisional patent application 61 / 434,355 filed January 19, 2011, US provisional patent application 61 / 435,326 filed January 23, 2011, 2011 Claims the benefit of US Provisional Patent Application No. 61 / 435,759, filed January 24, 2000. This application also includes US patent application Ser. No. 12 / 848,825, filed Aug. 2, 2010, U.S. Patent Application No. 12 / 889,719, filed Sep. 24, 2010, and 2010-12. This is a continuation-in-part application from US patent application Ser. No. 12 / 975,820 filed on Jan. 22, claiming their benefits.

  The present invention relates to solid state lamps and light bulbs, and more particularly, efficient and reliable light emitting diodes (CRI) with improved color rendering index (CRI) through separation of different phosphor components. LED) based lamps and light bulbs.

  Incandescent or filament-based lamps or bulbs are commonly used as light sources for residential and commercial facilities. However, such a lamp is a very inefficient light source, and about 95% of the input energy is lost mainly in the form of heat or infrared energy. Compact fluorescent lamps are more effective than incandescent lamps in terms of converting electrical power to light, but because toxic substances such as Hg must be used, such toxic substances can be used when disposing of the lamp. May contaminate the environment, including groundwater sources. One solution to improve the efficiency of a lamp or bulb is to use a solid state device such as a light emitting diode (one or more LEDs) rather than a metal filament to generate light.

  Light emitting diodes generally comprise one or more active layers of semiconductor material sandwiched between oppositely doped layers. When a bias is applied to the doped layer, holes and electrons are injected into the active layer where they recombine to generate light. Light is emitted from the active layer of the LED and from all surfaces.

  In order to use LED chips in circuits or other similar arrangements, it is known to encapsulate LED chips in packages to do environmental and / or mechanical protection, color selection, light collection, and the like. ing. The LED package also includes lead wires, contacts, or wirings for electrically connecting the LED package to an external circuit. In the exemplary LED package 10 illustrated in FIG. 1, a single LED or LED chip 12 is mounted on a reflective cup 13 using soldering or conductive epoxy. One or more wire bonds 11 connect the ohmic contacts of the LED chip 12 to leads 15A and / or 15B that can be attached to or integrated with the reflective cup 13. The reflective cup can be filled with an encapsulant 16 that can include a wavelength converting material such as a phosphor. The light emitted by the first wavelength LED can be absorbed by a phosphor capable of emitting light of the second wavelength in response. Next, the entire assembly can be encapsulated in a transparent protective resin 14, which can be molded into a lens shape so that the light emitted from the LED chip 12 is parallel. The reflection cup 13 can direct the light upward, but optical loss may occur when the light is reflected (that is, the reflectance of the practical reflector surface is less than 100%. Some can be absorbed by the reflective cup). In addition, depressive heat can be a problem for packages such as the package 10 shown in FIG. 1a because it is difficult to extract heat through the leads 15A, 15B. Because there is.

  The conventional LED package 20 illustrated in FIG. 2 may be more suitable for high power operation that may generate more heat. In the LED package 20, one or more LEDs 22 are mounted on a carrier such as a printed circuit board (PCB) carrier, substrate, or submount 23. A metal reflector 24 mounted on the submount 23 surrounds the LED chip (s) 22 and reflects light emitted by the LEDs 22 from the package 20. The reflector 24 also provides mechanical protection for the LED 22. One or more wire bond connections 27 are formed between the ohmic contacts on the LED chip 22 and the electrical wirings 25 </ b> A and 25 </ b> B on the submount 23. Subsequently, when the mounted LED 22 is covered with a sealing material 26, the sealing material 26 can provide a chip environment and mechanical protection while also functioning as a lens. The encapsulant 26 can also include one or more conversion materials (eg, phosphors) that absorb light from the LED chip and re-emit light with different wavelengths of light. The total radiation from the package 20 may be a combination of light from the LED 22 and re-emitted light from the conversion material. Metal reflector 24 is typically attached to the carrier using soldering or epoxy bonding.

  The LED as seen in the LED package 20 of FIG. 2 can also be coated with a conversion material that includes one or more phosphors, where the phosphor absorbs at least a portion of the LED light. The LEDs can emit light of different wavelengths to emit a combination of light from the LED and phosphor. LEDs can be coated with phosphors using a number of different methods, one suitable method being US Patent Application No. 11 / 656,759 to Chitnis et al. And US Patent Application No. 11 / 899,790. No., (both are the same), “Wafer Level Phosphor Coating Method and Devices Fabricated Method”. Alternatively, other methods such as electrophoretic painting (EPD) can be used to coat the LED, and this preferred EPD method is described in Tarsa et al. US patent application Ser. No. 11 / 473,089, entitled “Close Loop Electrophoretic”. “Deposition of Semiconductor Devices”.

  Lamps have also been developed that utilize solid state light sources, such as LEDs, with a conversion material that is either separated from the LEDs or remote from the LEDs. Such an arrangement is disclosed in Tarsa et al. US Pat. No. 6,350,041, entitled “High Output Radial Dispersing Lamp Using a Solid State Light Source”. The lamp described in this patent can include a solid state light source that transmits light through a separator to a diffuser having a phosphor. The diffuser can disperse light in a desired pattern and / or change its color by converting at least a portion of the light through a phosphor. In some embodiments, the separator provides sufficient spacing between the light source and the diffuser so that heat from the light source is not transferred to the diffuser when the light source is receiving a large current required for room illumination. Additional remote phosphor technology is described in Negley et al., US Pat. No. 7,614,759, entitled “Lighting Device”.

  The coded LEDs, LED packages, and solid state lamps described above can use multiple types of conversion materials, such as phosphors, to generate the desired overall radiation temperature and CRI. . Each of the phosphors can absorb light from the LED and re-emit light of a different wavelength. Some of these conventional arrangements can use green / yellow phosphors in combination with red phosphors, each of which typically absorbs blue LED light and is green / Emits yellow and red light. The re-emitted light can be combined with blue LED light to produce the desired emission characteristics.

  These conventional arrangements typically mix different phosphors at certain locations, such as LED coatings, LED package encapsulants, or lamp remote phosphors. One of the drawbacks of mixing phosphors is that there can be significant “crosstalk” or “overlap” between the emission and excitation spectra for different phosphors, which is combined Can negatively affect CRI and radiation efficiency for synchrotron radiation. FIG. 3 shows a graph 30 illustrating an example of emission and excitation characteristics for a conventional phosphor that can be mixed. The first graph 30 shows a red phosphor excitation spectrum 32, a green phosphor emission spectrum 34, and a red emission spectrum 36. The second graph 40 shows the same red phosphor emission excitation spectrum 32, yellow phosphor emission spectrum 42, and the same red phosphor emission spectrum 36. The shaded overlap regions 38, 44 show portions of the green and yellow emission spectra 34, 42 that overlap the red excitation spectrum 32. This overlap can result in “re-absorption” of the converted yellow / green phosphor light by the red phosphor. This converts some of the yellow / green color that would otherwise contribute to the overall emission to red. For lighting components that use these phosphors to produce white light obtained by combining light from LEDs and phosphors, re-absorption causes the resulting white light to be distorted on the black body curve of the CIE graph. Thus, the yellow / green peak emission can shift to red and the red peak can shift to blue. As a result, CRI can be reduced in overall radiation. There is also some efficiency loss associated with the phosphor absorption and emission process, and repeating this process through reabsorption of yellow / green light by the red phosphor results in an increase in efficiency loss.

US patent application Ser. No. 11 / 656,759 US patent application Ser. No. 11 / 899,790 US patent application Ser. No. 11 / 473,089 US Pat. No. 6,350,041 US Patent No. 7,614,759 US Provisional Patent Application No. 61 / 435,759 US Patent Application No. 2010/0155763 U.S. Patent Application No. 12 / 901,405

  The present invention is directed to LED packages and LED lamps and bulbs arranged to minimize loss of CRI and efficiency resulting from overlap of conversion material emission and excitation spectra. In different devices with this overlapping conversion material, the present invention reduces the probability that light re-emitted from the first conversion material will hit the second conversion material and minimizes the risk of reabsorption. The conversion material is configured as follows. In some embodiments, this risk is minimized by a different arrangement in which the two phosphors are separated.

  One embodiment of a solid state lamp according to the present invention comprises an LED and a first conversion material. The lamp further comprises a second conversion material positioned away from the first conversion material, and light from the LED passes through the second conversion material. The wavelength of the second conversion material is converted to re-emit at least part of the LED light, and less than 50% of the re-emitted light from the second phosphor enters the first conversion material. .

  Another embodiment of a solid state lamp according to the invention comprises a plurality of LEDs, at least one of the LEDs comprising a red phosphor. The red phosphor is arranged such that light from at least one of its LEDs passes through the red phosphor. The lamp also includes a yellow or green phosphor that is separated from the LED and rests on the LED, and the light from the LED also passes through the yellow or green phosphor.

  Yet another embodiment of a solid state lamp according to the present invention comprises an LED having a first phosphor coating, wherein the first phosphor absorbs part of the light emitted from the LED and has different wavelengths of light. Re-radiate. The lamp also includes a second phosphor disposed at a distance from the first phosphor, and light from the LED passes through the second phosphor. At least a portion of the LED light is absorbed by the second phosphor and re-emitted at each different wavelength of light. The emission spectrum of light re-emitted from the second phosphor overlaps with the excitation spectrum of the first phosphor, and most of the light from the second phosphor is in the first phosphor. I won't win.

  These and other aspects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings, which illustrate, by way of example, the features of the invention.

It is sectional drawing of one Example of a prior art LED lamp. FIG. 6 is a cross-sectional view of another embodiment of a prior art LED lamp. Fig. 3 is a graph showing the overlap between the excitation and emission spectra of two phosphors. 1 is a cross-sectional view of an embodiment of a lamp according to the present invention. FIG. 6 is a cross-sectional view of another embodiment of a lamp according to the present invention. 4 is a graph showing emission spectra of different lamps according to the present invention. FIG. 6 is a cross-sectional view of another embodiment of a lamp according to the present invention. FIG. 6 is a cross-sectional view of another embodiment of a lamp according to the present invention. FIG. 6 is a cross-sectional view of another embodiment of a lamp according to the present invention. FIG. 6 is a cross-sectional view of another embodiment of a lamp according to the present invention. FIG. 6 is a cross-sectional view of another embodiment of a lamp according to the present invention. FIG. 6 is a cross-sectional view of another embodiment of a lamp according to the present invention. 1 is a cross-sectional view of one embodiment of a lamp according to the present invention comprising an optical cavity. FIG. 6 is a cross-sectional view of another embodiment of a lamp according to the present invention that also includes an optical cavity. It is a CIE figure which shows the combination of a different illumination. FIG. 6 is a cross-sectional view of another embodiment of a lamp according to the present invention that also includes an optical cavity. FIG. 6 is a cross-sectional view of another embodiment of a lamp according to the present invention that also includes an optical cavity. FIG. 6 is a cross-sectional view of another embodiment of a lamp according to the present invention that also includes an optical cavity. FIG. 6 is an elevational view of another embodiment of a lamp according to the present invention. FIG. 20 is an exploded view of the lamp shown in FIG. 19. FIG. 6 is an exploded view of another embodiment of a lamp according to the present invention. FIG. 6 is an elevational view of yet another embodiment of a lamp according to the present invention. FIG. 6 is a perspective view of another embodiment of a lamp according to the present invention. 1 is a cross-sectional view of an embodiment of a lamp or display according to the present invention.

  The present invention is directed to different embodiments of solid state lamps, light bulbs, and LED packages that use multiple conversion materials to produce the desired overall emission characteristics, where the conversion materials are subject to overlapping emission and excitation spectra. It is separated to make it smaller. Some embodiments of the present invention reduce the warm color temperature by utilizing two individual phosphor components to eliminate or reduce reabsorption (interaction) between the two individual phosphor components. It is intended for a solid lamp arranged to generate white light having a light. As a result, warm white light with a significantly higher CRI can be emitted compared to arrangements where reabsorption is not addressed, such as mixing different phosphors.

  Reabsorption is minimized by making physical separation between the two phosphors, and interaction or crosstalk between the two phosphors is minimized. That is, the separation reduces the amount of light from the first phosphor that interacts with the second phosphor and reduces or eliminates reabsorption by the second phosphor. This in turn reduces CRI color misregistration that can be caused by this reabsorption.

  In some embodiments, the first phosphor passes through the second phosphor without the risk that light re-emitted from the first phosphor will be absorbed by the second phosphor. Thus, light having a wavelength that does not overlap with the excitation spectrum of the second phosphor can be re-emitted. However, the emission spectrum of the second phosphor may emit light that at least partially overlaps the excitation spectrum of the first phosphor. In an arrangement where the light from the second phosphor passes through the first phosphor, there may be a risk that the light from the second phosphor is reabsorbed by the first phosphor. Separating the phosphors minimizes the amount of re-radiated light that strikes the first phosphor, thereby minimizing the amount of light that may be reabsorbed by the first phosphor. To. In some embodiments, the emission spectrum of the first phosphor exceeds the excitation spectrum of the second phosphor so that light from the first phosphor can pass through the second phosphor. Materials that do not wrap may be included.

  In some embodiments, the second phosphor can include a yellow / green phosphor that absorbs blue light and re-emits yellow / green light, wherein the first phosphor is blue A red phosphor that absorbs light and emits red light can be included, and the emission spectrum of the yellow / green phosphor overlaps with the excitation spectrum of the red phosphor. In these embodiments, the first and second phosphors are separated so as to minimize the possibility that the emission of the yellow / green phosphor hits the red phosphor, and consequently The re-emitted yellow / green light is unlikely to be reabsorbed by the red phosphor. Compared to the mixed phosphor arrangement, separating the phosphor results in an overall lamp or package emission having higher CRI and higher phosphor efficiency.

  This separation can take many different forms that can provide different reductions in crosstalk between the first and second phosphors. In some embodiments, this separation can comprise a separation layer on the LED chip, each layer being a different one of the plurality of phosphors. The isolation layer can be a layer that rests on top of each other or can include layers that are aligned on the LED. This arrangement reduces the amount of crosstalk between the phosphors compared to the mixed embodiments, but a certain level of crosstalk remains because the two phosphors are close together.

  In other embodiments, one of the phosphors can be located remotely from the other phosphors, which can take many different forms. In some embodiments, one of the phosphors can comprise an insulating protective coat over one or more LEDs, and the second phosphor is like a dome over the LEDs. The shape may be at a position far away from the first phosphor. This arrangement further reduces the possibility that light emitted from the second phosphor will strike the first phosphor, thereby crossing between the first phosphor and the second phosphor. The possibility of talk is even lower.

  In yet another embodiment, the possibility of crosstalk is achieved by placing a first phosphor on the LED, such as in an LED package, and placing a second phosphor on the LED in its own package. It can be further lowered by arranging. These packages are mutually connected so that light emitted from the first phosphor in the first package is not emitted onto the second package and thus there is no opportunity for crosstalk between the two. Arranged in relation. In some embodiments, the emitters can be arranged adjacent to each other such that their emissions are combined as an overall lamp light, but not illuminating each other. There are many other arrangements that can provide such different levels of separation between the phosphors.

Other advantages may be provided by the present invention, including but not limited to cost savings. For separations where one of the phosphors is insulation protected on the LED, less insulation is typically used in the insulation protection coat. As a result, a more expensive phosphor can be used for the insulating protective coat. For example, a well-established yellow phosphor such as YAG: Ce ³⁺ is very cheap, but in contrast, a red phosphor such as a typical Eu-doped red phosphor is quite expensive. sell. By applying the red phosphor as an insulating protective coat, the amount of more expensive phosphor required for each system is reduced, resulting in cost savings.

  Another advantage of this arrangement is that placing at least one of the phosphors at a distance provides higher phosphor efficiency compared to a lamp with all phosphors on the LED chip. is there. One way to increase efficiency is to use the optical cavity effect induced in the space between the emitter and the remote phosphor. The remote phosphor configuration can provide greater flexibility in the design of highly reflective cavities compared to embodiments having a phosphor coating on the chip. Having a remote phosphor can also have thermal advantages. The remote phosphor can be insulated from chip heating, resulting in less thermal quenching of the phosphor material. A third advantage is that the quenching of the phosphor material is reduced. For some phosphors, these quantum efficiencies decrease with higher flux density through the phosphor material. By having a remote phosphor, the density of the light flux that passes through the phosphor is reduced, which can reduce quenching. When thermal quenching and quenching are reduced, a more stable light output can be obtained over time even when the operating temperature is high.

  Although the present invention has been described herein with reference to several embodiments, the present invention can be embodied in many different forms and can be embodied in the embodiments described herein. It is understood that this should not be construed as limiting. In particular, the present invention will be described below with respect to several LED packages, or several lamps having one or more LEDs or LED chips or LED packages of different configurations, although the present invention is many different configurations. It will be understood that it can be used for many other lamps having Illustrative examples of differently arranged lamps according to the present invention are described below and are incorporated herein by reference, such as Le et al., US provisional patent application 61/61, filed Jan. 24, 2011. No. 435,759, and the name “Solid State Lamp”.

  Different embodiments of the lamp can have many different shapes and sizes, and in some embodiments have dimensions that fit a standard size envelope, such as an A19 size envelope. This makes the lamp particularly useful as an alternative to conventional incandescent and fluorescent lamps or bulbs, and the lamp according to the present invention achieves a reduction in energy consumption and a longer life resulting from a solid state light source. The lamp according to the invention can also accommodate other types of standard size profiles including but not limited to A21 and A23.

  The following examples are described with reference to one or more LEDs, but it is understood that this is intended to encompass LED chips and LED packages. These components may have different shapes and larger sizes than those shown, and may include different numbers of LEDs.

  The present invention is described herein with reference to conversion materials, phosphors, phosphor layers, and related terms. The use of these terms should not be construed as limiting. The use of the term phosphor or phosphor layer is understood to mean that all wavelength converting materials are encompassed and equally applicable to them.

  The LED light source of the lamp consists of one or more LEDs, LED chips, or LED packages, and in some embodiments with multiple LEDs, the LEDs, LED chips, or LED packages have different emission wavelengths. It is also understood that Although the present invention is described below with reference to a phosphor conversion material, it is understood that many other conversion materials can be used. The present invention is described herein with reference to a conversion material, phosphor layer, that is remote from each other. Remote in this context refers to being isolated from direct thermal contact and / or not being in direct thermal contact on or in the surface. Also, although the present invention has been described with reference to LED chips, it is understood that this can include LEDs and LED packages.

  When an element such as a layer, region, or substrate is said to be “on” another element, it is understood that the element may be directly on the other element or there may be intervening elements. Furthermore, relative and similar terms such as “inner”, “outer”, “upper”, “higher”, “lower”, “below”, and “lower” are used herein to refer to one layer. Or it can be used to describe the relationship of another region. It will be understood that these terms are intended to encompass different directions of the device in addition to the directions shown in the figures.

  Although the phosphor is described herein with reference to a red-emitting phosphor, it is understood that this can include other colors that are close to red in the light spectrum, such as orange. . Phosphors are also described as emitting yellow light, but this may also include phosphors that emit green light.

  The terms first, second, etc. may be used herein to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, Layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from the other region, layer or section. As such, a first element, component, region, layer, or section described below can be referred to as a second element, component, region, layer, or section without departing from the teachings of the present invention.

  Embodiments of the present invention are described herein with reference to cross-section illustrations that are schematic illustrations of embodiments of the present invention. As such, the actual thickness of the layers may be different, for example, due to manufacturing techniques and / or tolerances, and expected to differ from the shape of the figure. Embodiments of the invention should not be construed as limited to the particular shapes of regions illustrated herein, but are to include deviations in shapes that result, for example, from manufacturing. is there. Regions illustrated or described as squares or rectangles typically have features that are rounded or curved due to normal manufacturing tolerances. As such, the regions illustrated in the figures are schematic in nature and their shapes are not intended to represent the exact shape of the region of the device and limit the scope of the invention It is not intended.

  FIG. 4 illustrates one embodiment of a lamp 40 according to the present invention comprising a plurality of LED chips 42 mounted on a carrier 44 that may comprise a printed circuit board (PCB) carrier, substrate, or submount. . The carrier 44 may include interconnecting electrical wiring (not shown) for applying electrical signals to the LED chip 42. Each of the LED chips 42 can include an LED 46, and an insulating protective coating of a first phosphor material 48 is applied on the LED 46. Many different commercially available LEDs that emit many different colors of light can be utilized, and many different phosphor materials can be used, such as one of those listed below. In some embodiments, the LED may comprise a conventional blue light emitting LED, and the conversion material includes a red phosphor that absorbs at least a portion of the blue light from the LED and re-emits red light. sell. In the illustrated embodiment, the red phosphor is arranged so that only a portion of the blue light from the LED chip is converted so that the LED chip emits both blue and red light. By passing a portion of the blue light through the red phosphor, the LED chip 42 need not operate in a state where the red phosphor is saturated. Thereby, it becomes possible to operate the LED chip 42 with higher radiation efficiency. In other embodiments, the red phosphor is arranged to operate in saturation by converting essentially all of the blue light to red, thus the LED chip emits substantially red light. be able to.

  The second phosphor 50 is provided in an isolated form on the LED chip 42, so that at least part of the light from the LED chip 42 passes through the second phosphor 50. The second phosphor 50 should be of a type that absorbs light of a wavelength from the LED chip 42 and re-radiates light of a different wavelength. In the illustrated embodiment, the second phosphor is dome-shaped on top of the LED chip, but the second phosphor takes many different shapes and sizes, such as disks or spheres. It is understood that it is possible. The second phosphor may be in the form of a phosphor carrier characterized as including a conversion material in the binder, but may also include a thermally conductive carrier and a light transmissive material. A phosphor disposed using a thermally conductive material is described in US Provisional Patent Application No. 61 / 339,516, filed March 3, 2010, which is incorporated herein by reference, under the name “LED Lamp”. Incorporating Remote Phosphor With Heat Dissipation Features ". When the second phosphor is formed in a dome shape, an open space is formed between the LED chip 42 and the second phosphor 50.

  In other examples, the encapsulant can be formed or mounted on the LED chip 42 and the second phosphor 50 can be formed or deposited as a layer on the top surface of the encapsulant. The encapsulant can take many different shapes, and in the illustrated embodiment is a dome shape. In still other embodiments having a sealant, the second phosphor 50 can be formed as a layer in the sealant or in the region of the sealant.

  Many different phosphors can be used in different embodiments according to the present invention, and the second phosphor in the illustrated embodiment absorbs blue light from the LED chip and emits yellow light. Includes light bodies. Many different phosphors can be used for the yellow conversion material comprising a commercially available YAG: Ce phosphor. As explained above, some of the blue light from the LED chip passes through the first (red) phosphor without being converted. Blue and red light from the LED chip 42 passes through the second phosphor, and part of the blue light is converted to yellow. A part of the blue light may pass through the second phosphor together with the red light from the LED chip 42. As a result, the lamp emits light that is obtained by combining blue, red, and yellow light, and in some embodiments, emits warm white light, which is a combination of light with a desired color temperature.

Blue light from the LED chip 42 can also be converted by many other phosphors that provide a full band of broad yellow spectrum radiation. Beyond the YAG: Ce mentioned above, these conversion materials can be made with phosphors based on the (Gd, Y) ₃ (Al, Ga) ₅ O ₁₂ : Ce system. Other yellow phosphors that can be used to generate white light when used with blue light emitting LED-based emitters are:
Tb _3-x RE _x O ₁₂ : Ce (TAG),
RE = Y, Gd, La, Lu, and Sr _2-xy Ba _x Ca _y SiO ₄ : Eu
Including, but not limited to.
The second phosphor 50 may also be arranged with a plurality of mixed yellow or green light emitting phosphors, or the second phosphor may comprise a plurality of layers of yellow or green light emitting phosphors. it can.

The first phosphor 48 on the LED chip 42 can include many different commercially available phosphors, such as a blue light from the LED chip and an Eu-doped red phosphor that can absorb red light.
Sr _x Ca _1-x S: Eu, Y, Y = halide,
CaSiAlN ₃ : Eu, or Sr _2-y Ca _y SiO ₄ : Eu
Other red-emitting phosphors containing can be used.

  Different sizes of phosphor particles can be used, including but not limited to particles ranging from 10 nanometers (nm) to 30 micrometers (μm), or larger. Smaller sized particles typically scatter and produce better color mixing and more uniform light generation than larger sized particles. Larger particles typically have a higher light conversion efficiency than smaller particles, but are less likely to emit uniform light. In some embodiments, the first and / or second phosphor can be provided in a binder, wherein the phosphor has different concentrations or loadings of phosphor material in the binder. Can also have. A typical concentration is a particle concentration in the range of 30-70% by weight. In one embodiment, the phosphor concentration for the first and second phosphors is about 65% by weight and is preferably uniformly dispersed. The first and second phosphors can also be formed in layers having different regions with different conversion materials and different concentrations of conversion material.

  If a phosphor is provided in the binder, different materials can be used, and the material is preferably robust after being cured and is substantially transparent in the visible wavelength spectrum. Suitable materials include silicones, epoxies, glasses, inorganic glasses, dielectrics, BCB, polyimides, polymers, and hybrids thereof, with the preferred materials being silicones that are highly transmissive and reliable in high power LEDs. Suitable phenyl and methyl-based silicones are commercially available from Dow (R) Chemical. The binder can be cured using many different curing methods depending on different factors such as the type of binder used. Different curing methods include, but are not limited to, curing with heat, ultraviolet (UV), infrared (IR), or air.

  The first phosphor 48 and the second phosphor 50 may be different processes including but not limited to spin coating, sputtering, printing, powder coating, electrophoretic coating (EPD), electrostatic coating, and the like. Can be applied using. Various painting methods and systems are described in Donofrio et al., US Patent Application Publication No. 2010/0155763, entitled “Systems and Methods for Application of Optical Materials to Optical Elements”, also in C. And is incorporated herein by reference. As mentioned above, the phosphor layer 48 can be applied with a binder material, but it is understood that a binder is not required. In yet another embodiment, the second phosphor can be separately processed into a dome shape and then mounted on the carrier layer 44 and the LED chip 42.

  The lamp is described in US Provisional Patent Application No. 61 / 339,515, entitled “LED Lamp With Remote Phosphor and Diffuser Configuration”, which is incorporated herein by reference. This application also describes a number of different shapes and sizes of the second phosphor, or phosphor carrier, that can also be used in the embodiments of the invention described herein.

  Alternatively, scattering materials can be used with the phosphor, and one such scattering material includes scattering particles. Scattering particles can also be included in a binder material that can be the same as described above with reference to the binder used with the first and second phosphors. Depending on the application and material used, different concentrations of scattering particles can be prepared. The preferred range of scattering particle concentration is from 0.01% to 0.2%, but it is understood that the concentration can be adjusted. In some embodiments, the concentration may be as low as 0.001%. It is also understood that the scattering particles can be at different concentrations within different regions. For some scattering particles, loss may increase due to absorption at higher concentrations. Therefore, the concentration of the scattering particles can be selected so as to maintain an allowable loss value, and at the same time, the light can be dispersed to obtain a desired radiation pattern.

The scattering particles can be composed of many different materials including, but not limited to:
silica,
Kaolin,
Zinc oxide (ZnO),
Yttrium oxide (Y ₂ O ₃ ),
Titanium dioxide (TiO ₂ ),
Barium sulfate (BaSO ₄ ),
Alumina (Al ₂ O ₃ ),
Fused silica (SiO ₂ ),
Fumed silica (SiO ₂ ),
Aluminum nitride,
Glass beads,
Zirconium dioxide (ZrO ₂ ),
Silicon carbide (SiC),
Tantalum oxide (TaO ₅ ),
Silicon nitride (Si ₃ N ₄ ),
Niobium oxide (Nb ₂ O ₅ ),
Boron nitride (BN) or phosphor particles (eg, YAG: Ce, BOSE)
Various scattering materials of various combinations of materials, or combinations of different forms of the same material can be used to provide a particular scattering effect. The scattering particles can take many different arrangements within the lamp.

  The lamp 40 can also include a reflective material / layer 56 on the surface of the carrier 44 that is not covered by the LED chip 42. The reflective layer 56 allows the lamp 40 to efficiently recycle photons and increases the lamp's radiation efficiency. The light emitted back toward the carrier is reflected by the reflective material / layer 56 so that absorption is reduced, and this light can contribute to useful radiation from the lamp. It is understood that the reflective layer 56 can comprise many different materials and structures, including but not limited to reflective metals such as distributed Bragg reflectors or multilayer reflective structures. It is also understood that the surface of the LED, as well as the first and second phosphors, can have a shape or texture that enhances light extraction.

  When an electrical signal is applied to the lamp 40 during operation, the LEDs in the LED chip 42 emit blue light that passes through the first phosphor 48. Part of the blue LED light is absorbed by the red phosphor 48 and re-emitted as red light. Some of the blue light also passes through the red first phosphor 48 without being converted, and the LED chip 42 emits both red and blue light. Light from the LED chip 42 is emitted through the second phosphor 50 and at least a portion of the blue light from the LED light is converted to yellow light, and in some embodiments, the light from the LED chip 42 A portion passes through the second phosphor 50 without being converted. As described above, this allows the lamp to emit white light obtained by combining blue light, red light, and yellow light.

  When the blue component of light from the LED chip is absorbed by the second phosphor 50, it is re-emitted in all directions. In the illustrated embodiment, when the phosphor particles absorb blue light, yellow light is re-emitted forward, exits the lamp, and returns toward the LED chip. The light radiated back toward the LED chip 42 may strike the first phosphor 48 on the LED chip 42. As described above, the excitation spectrum of many red phosphors overlaps with the emission spectrum of many yellow / green phosphors, so that the second phosphor 50 radiated back toward the LED chip 42. There is a risk that the light from will be absorbed by the first phosphor. This absorbed yellow light can be re-emitted as red light, which can result in a color shift in the overall lamp emission. As illustrated in the lamp 40, by spacing the second phosphor 50 (instead of mixing the phosphors), the light from the second phosphor strikes the first phosphor. The possibility is greatly reduced. Most of the emission path of yellow light from the second phosphor 50 does not hit the first phosphor and there is no risk of reabsorption. Much of the light emitted back toward the LED chip 42 is reflected from the reflective layer on the carrier 44 so as to contribute to useful radiation from the lamp.

  In some embodiments, the second phosphor is the first phosphor such that less than 50% of the re-emitted light of the second phosphor strikes or enters the first phosphor. Located away from the light body, and in other embodiments, less than 40% is placed away from or in contact with the first phosphor. In still other embodiments, less than 25% of the light of the second phosphor hits the first phosphor, and in other embodiments, less than 10% hits the first phosphor.

  Different lamps according to the present invention can be arranged in many different forms using many different characteristic shapes and materials. FIG. 5 shows another embodiment of a lamp 70 according to the present invention that has many similar features and components as the lamp 40 shown in FIG. 4 and described above, and operates in much the same way. Yes. With the understanding that the description of the lamp 40 applies equally to this embodiment using the same reference numbers, or other embodiments below, the same reference numbers are used for similar features and components.

The lamp 70 includes LED chips 42 each mounted on a carrier 44, and each LED chip 42 includes a blue light emitting LED coated with a red first phosphor 48. The uncovered surface of the carrier 44 can also be provided with a reflective layer 56. The lamp 70 comprises a second phosphor 72 on top of an LED chip that is arranged in much the same way as the second phosphor 50 described above. However, in this embodiment, the second phosphor 50 includes a phosphor material that absorbs blue light and re-emits green light. For example, the following phosphors:
SrGa ₂ S ₄ : Eu,
_{Sr 2-y Ba y SiO 4} : Eu,
SrSi ₂ O ₂ N ₂ : Eu
Lu ₃ Al ₅ O ₁₂ doped with Ce ³⁺ ,
(Ca, Sr, Ba) Si ₂ O ₂ N ₂ doped with Eu ²⁺
CaSc ₂ O ₄ : Ce 3 ⁺ and (Sr, Ba) ₂ SiO ₄ : Eu ²⁺
Can be used to generate green light.

  Lamp 70 operates in much the same way as lamp 40, but emits a combination of blue, red, and green light. In some embodiments, this combination can provide lamp emission that is warm white light having a desired temperature.

Beyond what is listed above, the following shows some additional suitable phosphors that may be used as the first or second phosphor. Each exhibits excitation in the blue and / or UV emission spectrum, yields the desired peak emission, has efficient light conversion, and has an acceptable stalk shift.
(Yellow / green)
(Sr, Ca, Ba) (Al, Ga) ₂ S ₄ : Eu ²⁺
Ba ₂ (Mg, Zn) Si ₂ O ₇ : Eu ²⁺
Gd _0.46 Sr _0.31 Al _1.23 O _x F _1.38 : Eu ²⁺ _0.06
(Ba _1-xy Sr _x Ca _y ) SiO ₄ : Eu
Ba ₂ SiO ₄ : Eu ²⁺
(red)
Lu ₂ O ₃ : Eu ³⁺
_{(Sr 2-x La x)} (Ce 1-x Eu x) O 4
Sr ₂ Ce _1-x Eu _x O ₄
Sr _2-x Eu _x CeO ₄
SrTiO ₃ : Pr ³⁺ , Ga ³⁺
CaAlSiN ₃ : Eu ²⁺
Sr ₂ Si ₅ N ₈ : Eu ²⁺

  FIG. 6 is a graph 80 showing the results of a comparison of the emission characteristics of a lamp with a mixed phosphor compared to a similar lamp with a separate phosphor described above. The first emission spectrum 82 is for a lamp with separated red and green phosphors, and the spectrum shows peaks in the blue, green, and red wavelength spectra. The second emission spectrum 84 is for a similar lamp with a mixed red and green phosphor, the blue peak drop and shift compared to the isolated spectrum 82, and even the red peak shift. Indicates. The total phosphor conversion efficiencies of both are approximately the same (42.5% for the separated phosphors and 46.1% for the mixed phosphors), but for the separated phosphors The CRI is about 88.5 of the separated phosphor relative to 78.5 of the mixed phosphor configuration.

  FIG. 7 shows yet another embodiment of a lamp 100 according to the present invention comprising a combination of different LED chips that emit different colors of light to produce the desired lamp emission. The lamp 100 comprises an LED chip 102 mounted on a carrier 104, which is similar to the carrier 44 described above. The carrier can have a reflective layer 105 covering its surface between the LED chips 102. The LED chip 102 can comprise a red light emitting LED chip 106 and a blue light emitting LED chip 108, which together can generate the desired red and blue light components of the lamp emission. The red LED chip 106 can comprise an LED 110 that is coated with a red phosphor 112 as described above, with some embodiments of the LED 110 emitting blue light, Absorbs at least part of the blue light and re-emits red light. In some embodiments, the red phosphor 112 can be arranged to absorb substantially all of the blue LED light, while in other embodiments, the red phosphor 112 can be one of the blue LED lights. It can be arranged to absorb only the part.

  Similar to the above embodiment, the second phosphor 114 is provided isolated above the LED chip 102, and the second phosphor absorbs blue light and re-emits yellow light. Including the body. In operation, red and blue light from the LED chip passes through the second phosphor and a portion of the blue light is converted to yellow. The lamp 100 emits white light obtained by combining blue, red, and yellow. As explained above, the separation between the red and yellow phosphors minimizes the risk that the red phosphor will re-absorb yellow light from the second phosphor. Can be.

  FIG. 8 shows another lamp 130 according to the present invention that is similar to the lamp 100. Instead of having a second phosphor that emits yellow, the lamp 130 is a portion of the blue light from the LED chip 102 such that the lamp emits white light obtained by combining blue, red, and green. And a second phosphor 132 that emits green light.

  As mentioned above, the lamp according to the invention can be arranged in many different forms using many different phosphor materials. FIG. 9 shows another embodiment of a lamp 140 according to the present invention comprising an LED chip 142 mounted on a carrier 144 as described above. However, in this embodiment, the LED chip comprises a blue light emitting LED 146 that uses an insulating protective coat of yellow first phosphor 148. The first phosphor 148 absorbs at least part of the light from the LED 146 and re-emits yellow light. The second phosphor 150 is in the form of a dome on the LED chip 142 and includes a red phosphor. Blue (and yellow) light from the LED chip 142 passes through the second phosphor 150 and at least a portion of the blue LED light is absorbed by the second phosphor and re-emitted as red light. . The lamp 140 emits white light obtained by combining blue, yellow, and red.

  FIG. 10 shows yet another embodiment of a lamp 160 according to the present invention having an LED chip 162 mounted on a carrier 164, each of the LED chip 162 comprising an LED 166 and a green first phosphor. 168 insulation protective coats are provided. At least a portion of the blue light from each of the LED chips 166 passes through the first phosphor 168 and is converted to green light, whereby each of the LED chips 162 emits green and blue light. The blue (and green) LED light passes through the second dome-shaped second red phosphor 170. At least a portion of the LED light is converted to red by the second phosphor, and the lamp 160 emits white light obtained by combining blue, red, and green light.

  FIG. 11 shows yet another embodiment of a lamp 180 according to the present invention having a blue light emitting LED chip 182 mounted on a carrier 184. Instead of providing an insulating protective coating on the LED chip 182, the first red phosphor 186 is provided in a dome shape on the LED chip 182, and the light from the LED chip 182 passes through the first phosphor 186. So, at least a part of it is converted to red light. A second green phosphor 188 is provided in the dome above the first phosphor 186 and the red light from the first phosphor 186 and the blue light from the LED chip 182 are second phosphor. It passes through the light body 188 where at least a portion of the light is converted to green light. The lamp emits white light obtained by combining blue, red and green light. The second phosphor 188 is shown on the first phosphor 186, but there can be a space between the first phosphor 186 and the second phosphor 188, and It is understood that the phosphors can be provided in a different order, such as a green phosphor on the inside and a red phosphor on the outside.

  FIG. 12 shows another embodiment of a lamp 190 according to the present invention having a blue light emitting LED chip 192 on a carrier 194. The lamp comprises red and green phosphors, and the phosphors shown are in different areas of the phosphor dome 196. In the illustrated embodiment, the red first phosphor 198 is at the top of the dome and the green second phosphor 200 is at the lower portion of the dome 196. Blue light from the LED chip passes through the first phosphor portion 198 and the second phosphor portion 200, where at least some of the LED light is converted into red light and green light, respectively. The lamp emits white light obtained by combining blue, red and green light. It will be understood that other embodiments may comprise different regions of the phosphor arranged differently. Each of the lamps shown in FIGS. 9-12 can include a reflective layer on the carrier as described above.

  As mentioned above, the lamps and their phosphors can be arranged in many different ways according to the invention. FIG. 13 shows yet another embodiment of a lamp 250 having an LED chip 252 mounted in the light cavity 254. Similar to the above example, the LED chip 252 can include an LED 256 that is coated with a first phosphor 258, and in some embodiments of the LED 256, emits blue light and the first phosphor. The light body is a red phosphor that absorbs at least part of the blue LED light and re-emits red light. In this embodiment, the red phosphor absorbs only a portion of the blue light from the LED, thereby causing the LED chip 252 to emit red and blue light.

  The LED chip 252 can be mounted on a carrier 260 similar to the carrier described above, and in the illustrated embodiment, the LED chip 252 and the carrier 260 can be mounted in the optical cavity 254. In other embodiments, the optical cavity can be mounted on a carrier around the LED chip. The carrier 260 can have a reflective layer 262 on the exposed surface between the LED chips 252 as described above, and the optical cavity 254 can transmit light out of the top opening of the optical cavity 254. A reflective surface 264 can be redirected.

  The second phosphor 266 is disposed over the opening of the optical cavity 254 and assumes a planar shape in the illustrated embodiment. However, it is understood that the second phosphor can take many different shapes including, but not limited to, a dome or a sphere. Similar to the above embodiment, the second phosphor 266 can include a phosphor that absorbs light from the LED chip 252 and emits light of a different color. In the illustrated embodiment, the second phosphor 266 includes one of the yellow phosphors described above that absorb blue light and re-emit yellow light. Similar to the above example, the blue and red light from the LED chip 252 passes through the second phosphor 266 and at least a portion of this blue light is absorbed by the yellow phosphor and re-generated as yellow light. Radiated. The lamp 250 can emit white light obtained by combining blue, red, and yellow light.

  The separation between the LED chip 252 and the second phosphor 266 greatly reduces the likelihood that yellow light from the second phosphor 266 will enter the red first phosphor 258. As in the above embodiment, this reduces the likelihood that yellow light will be absorbed by the red first phosphor and re-emitted as red light.

  FIG. 14 shows another embodiment of a lamp 280 according to the present invention having many of the same features as the lamp 250. However, in this embodiment, the second phosphor 282 includes a green-emitting phosphor that absorbs part of the blue light from the LED chip and re-emits green light. In operation, the lamp 280 emits white light obtained by combining the blue and red light from the LED chip and the green light from the second phosphor, and the separation between the first phosphors. As a result, reabsorption of green light by the first phosphor is minimized.

  Different embodiments can combine different lighting densities of lighting components to achieve a desired target color and temperature. FIG. 15 is a CIE diagram 290 showing different combinations of green and red illumination components combined on a blackbody curve at about 3000K. Combination 1 (Comb1) has the lowest green component in its emission spectrum, so that the spectrum needs to have a large red portion to achieve the desired color and temperature. Combination 2 (Comb2) has the largest green component and consequently has the lowest red component, while Combination 3 (Comb3) has the midpoint red and green components.

  FIG. 16 shows another embodiment of a lamp 300 according to the present invention having a blue LED chip 302 mounted on a carrier 304, the LED chip 302 being disposed in an optical cavity 306 having a reflective surface 308. The first phosphor 310 and the second phosphor 312 are configured in a planar shape of the opening of the optical cavity 306, but are arranged adjacent to each other, and the first red phosphor 310 is opened. Covering about half of the section, the second green (or yellow) phosphor 312 covers the remainder of the optical cavity opening. Blue light from the LED chip 302 passes through the phosphors 310 and 312 where some of it is converted to red light and green light, respectively. The lamp 300 emits white light obtained by combining blue, red, and green light. It will be appreciated that the phosphors can be arranged in many different arrangement areas and can be layered on top of each other.

  FIG. 17 shows another embodiment of a lamp 320 according to the present invention having a blue LED chip 322 mounted on a carrier 324, the LED chip 322 being disposed in the optical cavity 326. A planar first red phosphor 328 is disposed over the opening of the optical cavity 326 and a second green (or yellow) phosphor 330 is a dome over the first phosphor. Arranged in shape. The LED light passes through the first and second phosphors and is at least partially converted so that the lamp 320 emits white light obtained by combining blue, red, and green light.

  FIG. 18 shows another embodiment of a lamp 340 according to the present invention arranged in a manner similar to the lamp 320 shown in FIG. However, in this embodiment, the second green phosphor 342 is arranged in a spherical shape on the first phosphor 344, which is a more omnidirectional pattern of the second phosphor. Helps re-radiate light. In particular, this can facilitate the emission of downward light from the second phosphor 342.

  19 and 20 are U.S. Provisional Patent Application No. 61 / 339,515, filed March 3, 2010, the title “Lamp With Remote Phosphor and Diffuser Configuration”, and the U.S. Patent filed on Oct. 8, 2010. Shown is another embodiment of a lamp 350 according to the present invention similar to that illustrated and described in application Ser. No. 12 / 901,405, entitled “Non-Uniform Diffuser to Scatter Light In Uniform Emission Pattern”. ing. The lamp includes a submount or heat sink 352 and includes a dome shaped phosphor carrier 354 and a dome shaped diffuser 356. It also comprises an LED 358 mounted in this embodiment on the plane of the heat sink 352, with the phosphor carrier and diffuser on the LED chip 358. LED chip 358 and phosphor carrier 354 are described above, such as some embodiments having a first phosphor on LED chip 358 and a second phosphor in phosphor carrier 354. Although other arrangements and properties can be provided, other embodiments have first and second phosphors as part of the phosphor carrier 354. The lamp 350 can include a mounting mechanism of the type that fits into a conventional electrical socket. In the illustrated embodiment, the lamp 350 includes a threaded portion 360 for mounting to a standard Edison socket. Similar to the above embodiment, the lamp 350 can be equipped with a standard plug and the electrical socket can be a standard outlet or a GU24 based unit, or it can be a clip. The electrical socket can be a socket that receives and holds the clip (eg, as used in many fluorescent lamps).

  The lamp according to the present invention can include a power source or a power conversion unit that can be provided with a driver that turns on a light bulb from an AC line voltage / current and has a light control function for the light source. In some embodiments, the power supply can comprise an off-line constant current LED driver that uses a non-isolated quasi-resonant flyback topology. The LED driver can be implemented in the lamp 350, such as in the body portion 362, and can have a volume of less than 25 cubic centimeters in some embodiments, but has a volume of about 20 cubic centimeters in other embodiments. be able to. In some embodiments, the power source may be non-dimming and low cost. The power supplies used can have different topologies or geometric shapes and can be dimmable.

  The lamp embodiments described herein are adapted to meet the omnidirectional distribution standards set forth in the US Department of Energy (DOE) Energy Star, which is incorporated herein by reference. Can be arranged. One of the requirements of this standard that the lamp described herein meets is that the uniformity of radiation must be within 20% of the average viewing angle in the range of 0 to 135 °, and the lamp More than 5% of the total luminous flux from must be radiated in the radiation region of 135-180 °, and the measurements are made at azimuth angles of 0, 45, 90 °. The different lamp embodiments described herein can also include a modified A-type LED bulb that complies with the DOE Energy Star standard. The present invention provides an efficient, reliable and cost effective lamp. In some embodiments, the entire lamp can consist of five components that can be assembled quickly and easily.

  As explained above, and as shown in FIG. 16, different regions of the phosphor carrier can have different types of phosphors. In some embodiments, these different regions can result in phosphor carriers that appear to be patterned. FIGS. 21 and 22 show additional lamp embodiments 400, 450 similar to the lamp 350 shown in FIGS. The lamp also includes a submount or heat sink 352, a dome shaped diffuser 356, and an LED 358 that can be mounted on the planar surface of the heat sink 352 along with the diffuser 356 above the LED chip 358. In FIG. 21, the phosphor carrier 402 is provided between the LED 358 and the diffuser 356, and in FIG. 22, the phosphor carrier 452 is provided between the LED 358 and the diffuser 356. The LED chip 358 and the phosphor carriers 402, 452 can comprise any of the arrangements and characteristics described above. However, in these embodiments, the phosphor carriers 402, 452 comprise different first and second phosphors 404, 406, respectively, and the first and second phosphors are in different regions. For phosphor carrier 402, the first phosphor 404 covers most of the phosphor carrier region, and the second phosphor is a dot on the other regions of these phosphor carrier regions. Be placed. The entire phosphor carrier 404 appears to be patterned with dots. In other embodiments, the first phosphor can cover all of the phosphor carrier and the second phosphor can include dots on the first phosphor.

  For the phosphor carrier 452 of FIG. 22, the first phosphor 404 can cover most of the phosphor carrier and the second phosphor 406 is a stripe that covers the rest of the phosphor carrier. Can be included. In yet another embodiment, the first phosphor 404 can cover all of the phosphor carriers and the second phosphor 406 can cover the first phosphor in a stripe pattern. .

  These are just some of the many different patterns that can be provided on the phosphor carrier according to the invention. The phosphor carrier according to the invention may comprise a three-dimensional (eg dome-shaped) or planar transparent carrier material, the phosphor described above being on the outer or inner surface of the transparent carrier, or on both surfaces thereof. It is also understood that Some of the patterns described above may be on different phosphor carriers arranged in isolation. For example, the dot arrangement of one phosphor may be on a first phosphor carrier that is arranged isolated from a second phosphor carrier having the other phosphor. Different phosphor carriers can be planar or three-dimensional.

  FIG. 23 shows yet another embodiment of a lamp 460 according to the present invention comprising a first radiator package 462 comprising a green phosphor 464 and a second radiator package 466 comprising a red phosphor 468. Yes. The radiation from the packages 464, 466 is directional so that almost all of the light from each of the radiators does not enter the other. As a result, light from the green phosphor 414 does not enter the red phosphor 468, which can be reabsorbed. This type of lateral separation further reduces the amount of light that can be reabsorbed, thereby further reducing the negative impact that reabsorption can have on the lamp CRI.

  FIG. 24 illustrates yet another lamp or display 480 according to the present invention having a plurality of blue LED chips 482 spaced apart from a layer comprising a plurality of transmissive lamp / luminaire pixels 484. Show. Each pixel 484 may include red or green quantum dots or phosphors 486 and 488 that absorb blue light from LED chip 482 and emit red and green light, respectively. Diffuse or reflective material 490 is disposed between red phosphor 486 and green phosphor 488 or between adjacent pixels 484 to reduce interaction or crosstalk between adjacent conversion materials. sell. An efficiency improvement can be achieved by separating the red and green phosphors and placing a diffuser or reflective material 490 between the phosphors. The diffuser or reflective material may be optically opaque or translucent and serves to prevent light from one phosphor from being reabsorbed by another phosphor.

  Some of the above embodiments will be described with reference to a first insulating protective phosphor that is coated with a second phosphor disposed in isolation from the first phosphor, such as a dome shape. Has been. It will be appreciated that the second phosphor can be provided in many different shapes other than a dome, and that multiple phosphors can be provided in a dome shape. For example, the first phosphor can be provided in a dome shape over one or more LEDs, and the second phosphor is provided as a dome over the first dome. It is also understood that more than two phosphors can be used in different insulating protective coatings or separated in different dome-shaped arrangements. It is also understood that one or more phosphors can be used in combination with other phosphor disks, or can comprise a disk that can be used in combination with a phosphor sphere or dome. This separation can also include in-plane pixilation, such as in-plane separation of LEDs coated with different materials such as yellow and red phosphors. Also, there can be many variations on in-plane package separation as described above.

Although the present invention has been described with reference to certain preferred configurations thereof, other variations are possible. Accordingly, the spirit and scope of the present invention should not be limited to the forms described above.

Claims (49)

A solid lamp,
A light emitting diode (LED);
A first conversion material;
A second conversion material disposed away from the first conversion material, wherein light from the LED passes through the second conversion material, and the second conversion material is at least one of the LED lights. A solid-state lamp comprising a second conversion material that converts the wavelength of the light and re-radiates the light.   The lamp of claim 1, wherein light from the LED passes through the first conversion material, and at least a portion of the light from the LED is wavelength converted and re-radiated.   The lamp of claim 1, wherein the first conversion material has an excitation spectrum that overlaps a re-emission spectrum of the second conversion material.   The lamp of claim 1, wherein the first and second conversion materials comprise a phosphor.   The lamp of claim 1, wherein the second conversion material is on the first conversion material.   The lamp of claim 1, wherein the second conversion material comprises a dome over the first conversion material.   The lamp of claim 1, wherein the emission spectrum of the first conversion material does not overlap with the excitation spectrum of the second conversion material.   The lamp of claim 1, wherein the first conversion material absorbs light from the LED and re-emits red light.   The lamp of claim 1, wherein the second conversion material absorbs light from the LED and re-emits yellow or green light.   The lamp of claim 1, further comprising an optical cavity.   The lamp of claim 1, wherein less than 50% of the light re-emitted from the second conversion material falls within the first conversion material.   The lamp of claim 1, wherein less than 25% of the light re-emitted from the second conversion material enters the first conversion material.   The lamp of claim 1, which emits white light obtained by combining light from at least two of the LEDs, the first conversion material, and the light source comprising the second conversion material.   The lamp of claim 1, wherein the second phosphor is a sphere above the light emitting diode.   The lamp of claim 14, further comprising a diffuser on the sphere.   The lamp of claim 1, wherein the lamp emits light having a radiation pattern that conforms to the Energy Star standard.   The lamp of claim 1, wherein the lamp is sized to fit an A19 size profile.   The lamp of claim 1, wherein the second phosphor is planar.   The lamp of claim 1, further comprising a planar diffuser. A solid lamp,
A plurality of light emitting diodes (LEDs);
A red phosphor mounted on at least one of the LEDs, wherein the light from the at least one LED of the LEDs passes through the red phosphor; and
A solid lamp comprising a yellow or green phosphor separated from the LED and being yellow or green phosphor on the LED, wherein light from the LED passes through the yellow or green phosphor.   21. The lamp of claim 20, wherein the at least one LED of the plurality of LEDs emits blue light.   21. The lamp of claim 20, wherein the at least one LED of the plurality of LEDs is not coated with the red phosphor.   23. The lamp of claim 22, wherein the at least one uncoated LED emits blue light.   21. The lamp of claim 20, wherein the red phosphor absorbs a portion of light from at least one of the plurality of LEDs and re-emits at least a portion of red light.   21. The lamp of claim 20, wherein the yellow or green phosphor absorbs light from the LED and re-emits yellow or green light, respectively.   21. The lamp of claim 20, wherein the red phosphor has an excitation spectrum that overlaps with an emission spectrum of the yellow or green phosphor.   21. The lamp of claim 20, wherein the red phosphor comprises a conformal coat on one of the plurality of LEDs.   21. The lamp of claim 20, wherein the yellow or green phosphor is on the red phosphor.   21. The lamp of claim 20, wherein the yellow or green phosphor comprises a dome over the red phosphor.   The lamp of claim 20, further comprising an optical cavity.   21. The lamp of claim 20, wherein less than 50% of the light re-emitted from the yellow or green phosphor enters the red phosphor.   21. The lamp of claim 20, wherein less than 10% of the light re-emitted from the yellow or green phosphor enters the red phosphor.   21. The lamp of claim 20 that emits white light obtained by combining light from at least two of the LED, the red phosphor, and the yellow or green phosphor.   21. The lamp of claim 20, wherein the lamp emits light in an energy star compliant radiation pattern.   21. The lamp of claim 20, wherein the lamp is sized to fit an A19 size profile. A solid lamp,
A light emitting diode (LED) having a first phosphor coating that absorbs a portion of the light emitted from the LED and re-radiates light of a different wavelength;
A second phosphor disposed away from the first phosphor, wherein light from the LED passes through the second phosphor, and the second phosphor is the LED The emission spectrum of the light that absorbs at least part of the light, re-radiates light of each different wavelength, and is re-emitted from the second phosphor is the excitation spectrum of the first phosphor A solid-state lamp comprising: a second phosphor that overlaps with the second phosphor so that most of the light from the second phosphor does not strike the first phosphor.   37. The lamp of claim 36, wherein the second phosphor is on the first phosphor.   37. The lamp of claim 36, wherein the second phosphor comprises a dome over the first phosphor.   37. The lamp of claim 36, wherein the emission spectrum of the first phosphor does not overlap with the excitation spectrum of the second phosphor.   37. The lamp of claim 36, wherein the LED emits blue light.   37. The lamp of claim 36, wherein the first phosphor absorbs light from the LED and re-emits red light.   37. The lamp of claim 36, wherein the second phosphor absorbs light from the LED and re-emits yellow or green light.   The first phosphor comprises a red phosphor, the second phosphor comprises a yellow or green phosphor, and the red phosphor emits the light emitted by the yellow or green phosphor. 37. The lamp of claim 36, having an excitation spectrum that at least partially overlaps the spectrum.   The lamp of claim 36, further comprising an optical cavity.   37. The lamp of claim 36, wherein less than 50% of the light re-emitted from the second phosphor enters the first phosphor.   37. The lamp of claim 36, wherein less than 10% of the light re-emitted from the second phosphor enters the first phosphor.   37. The lamp of claim 36 that emits white light obtained by combining light from at least two of the LED, the first phosphor, and the second phosphor.   37. The lamp of claim 36 that emits light in an energy star compliant radiation pattern. 37. The lamp of claim 36, wherein the lamp is sized to fit an A19 size profile.