Patent Application
20140232288
The present subject matter generally relates to lighting apparatuses and related methods and, more particularly, to solid state lighting apparatuses and related methods.
Solid state lighting arrays are used for a number of lighting applications. For example, lighting panels including arrays of solid state light emitting devices have been used as direct illumination sources in applications including architectural and/or accent lighting. A solid state light emitting device may include, for example, a packaged light emitting device including one or more light emitting diodes (LEDs), which may include inorganic LED chips and/or organic LED chips (OLEDs). Typically, solid state light emitting devices generate light through the recombination of electronic carriers (electrons and holes) in a light emitting layer or region of a LED chip. LEDs have significantly longer lifetimes and typically have significantly greater luminous efficiency than conventional incandescent and fluorescent light sources; however, LEDs are narrow-band emitters, and it can be challenging to simultaneously provide good color rendering in combination with high luminous efficacy.
Aspects relating to the subject matter disclosed herein may be better understood with reference to the 1931 CIE (Commission International de I'Eclairage) Chromaticity Diagram, which is well-known and readily available to those of ordinary skill in the art. The 1931 CIE Chromaticity Diagram maps out the human color perception in terms of two CIE parameters x and y. The spectral colors are distributed around the edge of the outlined space, which includes all of the hues perceived by the human eye. The boundary line represents maximum saturation for the spectral colors. The chromaticity coordinates (i.e., color points) that lie along the blackbody locus obey Planck's equation: E(λ)=A λ−5/(eB/T−1) 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 1931 CIE Diagram includes temperature listings along the blackbody locus (embodying a curved line emanating from the right corner). 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 bluish. 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 that is on or near the blackbody locus can thus be described in terms of their color temperature.
LEDs typically receive a direct current (DC) input signal or a modulated square wave input signal so that a constant current flows through the LEDs when in an “on” state. A current value is typically set to provide high conversion efficiency. LED light sources with variable intensity may be controlled by changing duty factor of a modulated square wave input signal.
Conventional lighting systems for use in buildings are powered by an alternating current (AC) source; accordingly, a LED-based light source for use in buildings typically includes an AC-DC power converter. An AC-DC power converter often represents a significant fraction of the overall cost of a LED-based light source, and power losses inherent to such a power converter reduces overall efficiency of the light source. Additionally, AC-DC power converters are generally not as reliable as LEDs, and therefore can limit the operating lifetime of a LED light source.
To avoid disadvantages associated with use of AC-DC power converters, it has been proposed to operate a LED light source directly from an AC power source without AC-DC conversion. Multiple groups or sets of series-connected LEDs may be powered by different portions of an AC waveform. For instance, one group may be powered on when the amplitude of the AC waveform is positive, and another group may be powered on when the amplitude of the AC waveform is negative; however, this simple driving scheme typically suffers from flicker and reduced efficiency. To provide somewhat improved efficiency, a full-wave rectifier may be used; however, the resulting light source still has limited efficiency and may exhibit flicker.
Since LEDs emit light with narrow wavelength spectrum, it is often necessary to utilize LEDs having different peak wavelengths (e.g., different colors) in a single LED light source in order to generate light with desirably high color rendering characteristics. If multiple groups of LEDs including LEDs having different peak wavelengths are utilized in a light source lacking an AC-DC power converter, however, then it may be challenging to avoid perceptible variations in color of light (e.g., with respect to area) output by such a light source, particularly if multiple LEDs having different peak wavelengths are distributed over a large area. Whether or not LEDs have different peak wavelengths, another challenge with utilizing multiple groups of LEDs in a light source lacking an AC-DC power converter (particularly when multiple LEDs distributed over a large area) is avoiding perceptible variations in intensity of light (e.g., with respect to area) output by such a light source.
Still another challenge associated with utilizing multiple groups of LEDs in a light source lacking an AC-DC power converter is thermal management—including efficiently dissipating heat generated by LEDs without overheating individual LEDs (which would shorten LED lifetime) and without needlessly increasing heatsink area (which would increase cost and size of a light source).
Another challenge associated with solid state lighting apparatuses includes providing the ability to vary beam patterns while avoiding use of mechanical elements that would require periodic maintenance and/or would be subject to failure long before the service life of solid state light emitters. Still another challenge associated with solid state light apparatuses includes providing the ability to vary color temperature without unduly increasing cost or complexity of a lighting apparatus.
Accordingly, a need exists for improved solid state lighting apparatuses and/or improved methods including use of solid state lighting apparatuses that can be directly coupled to an AC voltage signal, without requiring use of an on-board switched mode power supply. Desirable solid state lighting apparatuses and methods would exhibit reduced flicker, reduced variation in color with respect to area, reduced variation in light intensity with respect to area, and/or improved thermal management.
Solid state lighting apparatuses adapted to operate with alternating current (AC) received directly from an AC power source and related methods are disclosed. In one aspect, an exemplary solid state lighting apparatus can comprise a substrate and multiple sets of one or more solid state light emitters arranged on or supported by the substrate. At least first and second sets of the multiple sets of solid state light emitters can be configured to be activated and/or deactivated at different times relevant to one another during a portion of an AC cycle. The first and second sets of the multiple sets of solid state light emitters can also comprise different duty cycles.
Notably, solid state lighting apparatuses described herein can comprise various emitter configurations, color combinations, and/or circuit components adapted to reduce perceivable flicker, perceivable color shifts, and/or perceivable spatial variations in luminous flux that could potentially occur during activation and/or deactivation of multiple sets of different solid state light emitters. Solid state lighting apparatus described herein may also permit color temperature and/or beam pattern to be adjusted.
In one aspect, a solid state lighting apparatus is adapted to operate with alternating current (AC) received from an AC power source, the lighting apparatus comprising: a substrate; and multiple sets of one or more solid state light emitters arranged on or supported by the substrate, wherein at least first and second sets of the multiple sets of solid state light emitters are configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, and wherein the first and second sets of the multiple sets of solid state light emitters comprise different duty cycles; wherein at least one solid state light emitter of the first set of solid state light emitters comprises a largest duty cycle of the different duty cycles and is arranged closer in proximity to at least one solid state emitter of the second solid state light emitter set comprising a smallest duty cycle of the different duty cycles than in proximity to any other solid state light emitter of the multiple sets of solid state light emitters.
In another aspect, a solid state lighting apparatus is adapted to operate with alternating current (AC) received from an AC power source, the lighting apparatus comprising: a substrate; and an array of solid state light emitters arranged on or supported by the substrate, wherein the array includes a plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle; wherein, within the array of solid state light emitters, at least one solid state light emitter of a first solid state light emitter set is arranged closer to at least one solid state emitter of a second solid state light emitter set than to any other solid state light emitter of the first solid state light emitter set.
In another aspect, a solid state lighting apparatus is adapted to operate with alternating current (AC) received from an AC power source, the lighting apparatus comprising: an array of solid state light emitters arranged on or supported by a substrate, the array comprising a plurality of mutually exclusive solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the plurality sets are adapted to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, and wherein the at least two different solid state light emitter sets comprise different duty cycles; wherein the array comprises multiple solid state light emitters distributed across a central portion of the substrate, and comprises multiple solid state light emitters distributed across a peripheral portion of the substrate; and wherein the central portion comprises more solid state light emitters than the peripheral portion.
In yet another aspect, a lighting apparatus adapted to operate with alternating current (AC) received from an AC power source, the lighting apparatus comprising: an array of solid state light emitters arranged on or supported by a common substrate and including a plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle; wherein the array is distributed across a region of the substrate; and wherein, for each set of the solid state light emitter sets, the multiple solid state light emitters are symmetrically arranged within or along the region.
In still another aspect, lighting apparatus is adapted to operate with alternating current (AC) received from an AC power source, the lighting apparatus comprising: an array of solid state light emitters arranged on or supported by a common substrate and including a plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle; wherein the lighting device comprises at least one of the following features (a) and (b): (a) at least one solid state light emitter set of the plurality of solid state light emitter sets is arranged to emit at least one peak wavelength that differs by at least 30 nm from at least one peak wavelength emitted by at least one other solid state light emitter set of the plurality of solid state light emitter sets; and (b) at least one solid state light emitter set of the plurality of solid state light emitter sets is arranged to emit a first peak wavelength and to emit a second peak wavelength that differs from the first peak wavelength by at least 30 nm.
In another aspect, a lighting apparatus adapted to operate with alternating current (AC) received from an AC power source, the lighting apparatus comprising: an array of solid state light emitters arranged on or supported by a common substrate and including a plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least three different solid state light emitter sets of the plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle; and wherein each solid state light emitter set of the at least three different solid state light emitter sets is independently arranged to emit light having x, y color coordinates within four MacAdam step ellipses of a reference point on the blackbody locus of a 1931 CIE Chromaticity Diagram and having a color temperature that differs by at least 400 K relative to a color temperature of each other solid state light emitter set of the at least three different solid state light emitter sets.
In yet another aspect, a lighting apparatus is adapted to operate with alternating current (AC) received from an AC power source, and the lighting apparatus comprises: an array of solid state light emitters arranged on or supported by a body structure and including a plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle; at least one reflector and/or at least one optical element arranged to receive emissions from the plurality of solid state light emitter sets, and arranged to affect a beam pattern generated by the lighting device; and a control element arranged to permit adjustment of duty cycle of each solid state light emitter set of the at least two solid state light emitter sets, and thereby permit adjustment of said beam pattern.
In yet another aspect, a lighting apparatus is adapted to operate with alternating current (AC) received from an AC power source, and the lighting apparatus comprises: a first array of solid state light emitters arranged on or supported by a first substrate and including a first plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the first plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle; a second array of solid state light emitters arranged on or supported by a second substrate and including a second plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the second plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle; and a support plate comprising a plurality of substrate mounting regions including a first substrate mounting region arranged to receive the first substrate and including a second substrate mounting region arranged to receive the second substrate.
In another aspect, the invention relates to a solid state lighting apparatus adapted to operate with alternating current (AC) received from an AC power source, the lighting apparatus including: a substrate; and multiple sets of solid state light emitters, each including multiple solid state light emitters, arranged on or supported by the substrate, wherein at least first and second sets of the multiple sets of solid state light emitters are configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, and wherein the at least first and second sets of the multiple sets of solid state light emitters comprise different duty cycles; the apparatus comprising at least one of the following features (i) and (ii): the first set of solid state light emitters comprises a largest duty cycle of the different duty cycles and consists of a greater number of solid state light emitters than any other set of the multiple sets of solid state light emitters; and the second set of solid state light emitters comprises a smallest duty cycle of the different duty cycles and consists of a smaller number of solid state light emitters of the multiple sets of solid state light emitters.
In yet another aspect, the invention relates to a solid state lighting apparatus adapted to operate with alternating current (AC) received from an AC power source, the lighting apparatus including: multiple substrate regions; and multiple sets of one or more solid state light emitters arranged on or supported by the multiple substrate regions, wherein at least first and second sets of the multiple sets of solid state light emitters are configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, wherein the first and second sets of the multiple sets of solid state light emitters comprise different duty cycles; and wherein the lighting apparatus comprises at least one of the following features (i) to (iii): (i) a first substrate region of the multiple substrate regions includes one or more solid state light emitters of the first set of solid state light emitters and includes one or more solid state light emitters of the second set of solid state light emitters; and a second substrate region of the multiple substrate regions is non-coplanar with the first substrate region and includes one or more solid state light emitters of the first set of solid state light emitters and includes one or more solid state light emitters of the second set of solid state light emitters; (ii) at least one first solid state light emitter of the first set of solid state light emitters is arranged on a first substrate region of the multiple substrate regions that is substantially parallel to a first plane, at least one second solid state light emitter of the second set of solid state light emitters is arranged on a second substrate region of the multiple substrate regions that is substantially parallel to a second plane that is non-coplanar with the first plane but oriented less than 30 degrees apart from the first plane, and at least a portion of emissions of the at least one first solid state emitter are arranged to mix or overlap with at least a portion of emissions of the at least one second solid state emitter; and (iii) at least one first solid state light emitter of the first set of solid state light emitters is arranged on a first substrate region of the multiple substrate regions and is arranged to output a first beam centered in a first direction, and at least one second solid state light emitter of the second set of solid state light emitters is arranged on a second substrate region of the multiple substrate regions and is arranged to output a second beam centered in a second direction that is non-parallel to the first direction but oriented less than 30 degrees apart from the first direction.
In another aspect, the invention relates to a method comprising illuminating an object, a space, or an environment, utilizing at least one lighting apparatus as described herein.
In another aspect, any of the foregoing aspects, and/or various separate aspects and features as described herein, may be combined for additional advantage. Any of the various features and elements as disclosed herein may be combined with one or more other disclosed features and elements unless indicated to the contrary herein.
Other aspects, features and embodiments of the invention will be more fully apparent from the ensuing disclosure and appended claims.
A full and enabling disclosure of the present subject matter is set forth more particularly in the remainder of the specification, including reference to the accompanying figures relating to one or more embodiments, in which:
The present invention relates in certain aspects to solid state lighting apparatuses adapted to operate with alternating current (AC) received directly from an AC power source and related methods. Exemplary solid state lighting apparatuses can comprise a substrate and multiple sets of one or more solid state light emitters arranged on or supported by the substrate. At least first and second sets of the multiple sets of solid state light emitters can be configured to be activated and/or deactivated at different times relevant to one another during a portion of an AC cycle. More than two sets of solid state light emitters may be provided, and different sets of solid state light emitters may also comprise different duty cycles. Notably, solid state lighting apparatuses described herein can comprise various emitter configurations, color combinations, and/or circuit components adapted to reduce perceivable flicker, perceivable color shifts, and/or perceivable spatial variations in luminous flux that could potentially occur during activation and/or deactivation of multiple sets of different solid state light emitters. Solid state lighting apparatus described herein may also permit color temperature and/or beam pattern to be adjusted.
Unless otherwise defined, terms used herein should be construed to have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Embodiments of the invention are described herein with reference to cross-sectional, perspective, elevation, and/or plan view illustrations that are schematic illustrations of idealized embodiments of the invention. Variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected, such that embodiments of the invention should not be construed as limited to particular shapes illustrated herein. This invention may be embodied in different forms and should not be construed as limited to the specific embodiments set forth herein. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity.
Unless the absence of one or more elements is specifically recited, the terms “comprising,” “including,” and “having” as used herein should be interpreted as open-ended terms that do not preclude the presence of one or more elements.
The terms “LEDs” and “LED chips” are synonymous and refer to solid state light emitting devices or solid state light emitters as described hereinbelow.
It will be understood that when an element such as a layer, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present. Moreover, relative terms such as “on”, “above”, “upper”, “top”, “lower”, or “bottom” are used herein to describe one structure's or portion's relationship to another structure or portion as illustrated in the figures. It will be understood that relative terms such as “on”, “above”, “upper”, “top”, “lower” or “bottom” are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, structure or portion described as “above” other structures or portions would now be oriented “below” the other structures or portions.
The terms “electrically activated emitter” and “emitter” as used herein refers to any device capable of producing visible or near visible (e.g., from infrared to ultraviolet) wavelength radiation, including but not limited to, xenon lamps, mercury lamps, sodium lamps, incandescent lamps, and solid state emitters, including diodes (LEDs), organic light emitting diodes (OLEDs), and lasers.
The terms “solid state light emitter” or “solid state emitter” may include a light emitting diode, laser diode, organic light emitting diode, and/or other semiconductor device preferably arranged as a semiconductor chip that includes one or more semiconductor layers, which may include silicon, silicon carbide, gallium nitride and/or other semiconductor materials, a substrate which may include sapphire, silicon, silicon carbide and/or other microelectronic substrates, and one or more contact layers which may include metal and/or other conductive materials.
It will be understood that the terms “groups”, “segments”, or “sets” as used herein are synonymous terms. As used herein, these terms generally describe how multiple LED chips can be electrically connected in series, in parallel, or in mixed series/parallel configurations among mutually exclusive groups/segments/sets.
The term “substrate” as used herein in connection with lighting apparatuses refers to a mounting element on which, in which, or over which multiple solid state light emitters (e.g., emitter chips) may be arranged or supported (e.g., mounted). Exemplary substrates useful with lighting apparatuses as described herein include printed circuit boards (including but not limited to metal core printed circuit boards, flexible circuit boards, dielectric laminates, and the like) having electrical traces arranged on one or multiple surfaces thereof, support panels, and mounting elements of various materials and conformations arranged to receive, support, and/or conduct electrical power to solid state emitters. A unitary substrate may be used to support multiple groups of solid state emitter components, and may further be used to support related circuits and/or circuit elements, such as driver circuit elements, rectifier circuit elements (e.g., a rectifier bridge), current limiting circuit elements, current diverting circuit elements, and/or dimmer circuit elements. In certain embodiments, a substrate may include multiple emitter mounting regions each arranged to receive one or more solid state light emitters or sets of solid state light emitters. In certain embodiments, substrates may include conductive regions arranged to conduct power to solid state light emitters or solid state light emitter groups arranged thereon or thereover. In other embodiments, substrates may be insulating in character, and electrical connections to solid state emitters may be provided by other means (e.g., via conductors not associated with substrates).
Solid state light emitting devices according to embodiments of the invention may include III-V nitride (e.g., gallium nitride) based LED chips or laser chips fabricated on a silicon, silicon carbide, sapphire, or III-V nitride growth substrate, including (for example) devices manufactured and sold by Cree, Inc. of Durham, N.C. Such LEDs and/or lasers may be configured to operate such that light emission occurs through the substrate in a so-called “flip chip” orientation. Such LED and/or laser chips may also be devoid of growth substrates (e.g., following growth substrate removal).
LED chips useable with lighting devices as disclosed herein may include horizontal devices (with both electrical contacts on a same side of the LED) and/or vertical devices (with electrical contacts on opposite sides of the LED). A horizontal device (with or without the growth substrate), for example, may be flip chip bonded (e.g., using solder) to a carrier substrate or printed circuit board (PCB), or wire bonded. A vertical device (without or without the growth substrate) may have a first terminal solder bonded to a carrier substrate, mounting pad, or printed circuit board (PCB), and have a second terminal wire bonded to the carrier substrate, electrical element, or PCB.
Electrically activated light emitters (including solid state light emitters) may be used individually or in groups to emit one or more beams to stimulate emissions of one or more lumiphoric materials (e.g., phosphors, scintillators, lumiphoric inks, quantum dots) to generate light at one or more peak wavelength, or of at least one desired perceived color (including combinations of colors that may be perceived as white). Inclusion of lumiphoric (also called ‘luminescent’) materials in lighting devices as described herein may be accomplished by direct coating on lumiphor support elements or lumiphor support surfaces (e.g., by powder coating, inkjet printing, or the like), adding such materials to lenses, and/or by embedding or dispersing such materials within lumiphor support elements or surfaces. Other materials, such as light scattering elements (e.g., particles) and/or index matching materials may be associated with a lumiphoric material-containing element or surface. In certain embodiments, one or more lumiphoric materials may be located remotely from (e.g., spatially segregated from) multiple sets of one or more solid state emitters and supported by a lumiphor support element (e.g., transparent or other light transmissive support), with the at least one lumiphoric material being arranged to be stimulated by emissions of at least some solid state light emitters of multiple sets of solid state light emitters. LED devices and methods as disclosed herein may include have multiple LEDs of different colors, one or more of which may be white emitting (e.g., including at least one LED with one or more lumiphoric materials).
In certain embodiments, one or more short wavelength solid state emitters (e.g., blue and/or cyan LED) may be used to stimulate emissions from a mixture of lumiphoric materials, or discrete layers of lumiphoric material, including red, yellow, and green lumiphoric materials. In certain embodiments, multiple groups of solid state emitters may include at least three independently controlled short wavelength (e.g., blue or cyan) LEDs, with a first short wavelength LED arranged to stimulate emissions of a first red lumiphor, a second short wavelength LED arranged to stimulate emissions of a second yellow lumiphor, and a third short wavelength LED arranged to stimulate emissions of a third red lumiphor. Such LEDs of different wavelengths may be present in the same group of solid state emitters, or may be provided in different groups of solid state emitters.
The expression “peak wavelength”, as used herein, means (1) in the case of a solid state light emitter, to the peak wavelength of light that the solid state light emitter emits if it is illuminated, and (2) in the case of a lumiphoric material, the peak wavelength of light that the lumiphoric material emits if it is excited.
A wide variety of wavelength conversion materials (e.g., luminescent materials, also known as lumiphors or luminophoric media, e.g., as disclosed in U.S. Pat. No. 6,600,175 and U.S. Patent Application Publication No. 2009/0184616), are well-known and available to persons of skill in the art. Examples of luminescent materials (lumiphors) include phosphors, scintillators, day glow tapes, nanophosphors, quantum dots (e.g., such as provided by NNCrystal US Corp. (Fayetteville, Ark.)), and inks that glow in the visible spectrum upon illumination with (e.g., ultraviolet) light. One or more luminescent materials useable in devices as described herein may be down-converting or up-converting, or can include a combination of both types.
Some embodiments of the present invention may use solid state emitters, emitter packages, fixtures, luminescent materials/elements, power supply elements, control elements, and/or methods such as described in U.S. Pat. Nos. 7,564,180; 7,456,499; 7,213,940; 7,095,056; 6,958,497; 6,853,010; 6,791,119; 6,600,175, 6,201,262; 6,187,606; 6,120,600; 5,912,477; 5,739,554; 5,631,190; 5,604,135; 5,523,589; 5,416,342; 5,393,993; 5,359,345; 5,338,944; 5,210,051; 5,027,168; 5,027,168; 4,966,862, and/or 4,918,497, and U.S. Patent Application Publication Nos. 2009/0184616; 2009/0080185; 2009/0050908; 2009/0050907; 2008/0308825; 2008/0198112; 2008/0179611, 2008/0173884, 2008/0121921; 2008/0012036; 2007/0253209; 2007/0223219; 2007/0170447; 2007/0158668; 2007/0139923, and/or 2006/0221272; with the disclosures of the foregoing patents and published patent applications being hereby incorporated by reference as if set forth fully herein.
The expression “lighting device” or “lighting apparatus,” as used herein, is not limited, except that it is capable of emitting light. That is, a lighting device or lighting apparatus can be a device or apparatus that illuminates an area or volume, e.g., a structure, a swimming pool or spa, a room, a warehouse, an indicator, a road, a parking lot, a vehicle, signage, e.g., road signs, a billboard, a ship, a toy, a mirror, a vessel, an electronic device, a boat, an aircraft, a stadium, a computer, a remote audio device, a remote video device, a cell phone, a tree, a window, an LCD display, a cave, a tunnel, a yard, a lamppost, or a device or array of devices that illuminate an enclosure, or a device that is used for edge or back-lighting (e.g., backlight poster, signage, LCD displays), light bulbs, bulb replacements (e.g., for replacing AC incandescent lights, low voltage lights, fluorescent lights, etc.), outdoor lighting, security lighting, exterior residential lighting (wall mounts, post/column mounts), ceiling fixtures/wall sconces, under cabinet lighting, lamps (floor and/or table and/or desk), landscape lighting, track lighting, task lighting, specialty lighting, rope lights, ceiling fan lighting, archival/art display lighting, high vibration/impact lighting-work lights, etc., mirrors/vanity lighting, or any other light emitting device. In certain embodiments, lighting devices or lighting apparatuses as disclosed herein are self-ballasted.
The inventive subject matter further relates in certain embodiments to an illuminated enclosure (the volume of which can be illuminated uniformly or non-uniformly), comprising an enclosed space and at least one lighting device or lighting apparatus as disclosed herein, wherein the lighting device or apparatus illuminates at least a portion of the enclosure (uniformly or non-uniformly). The inventive subject matter further relates to an illuminated area, comprising at least one item, e.g., selected from among the group consisting of a structure, a swimming pool or spa, a room, a warehouse, an indicator, a road, a parking lot, a vehicle, signage, e.g., road signs, a billboard, a ship, a toy, a mirror, a vessel, an electronic device, a boat, an aircraft, a stadium, a computer, a remote audio device, a remote video device, a cell phone, a tree, a window, a LCD display, a cave, a tunnel, a yard, a lamppost, etc., having mounted therein or thereon at least one lighting device or apparatus as described herein. Methods include illuminating an object, a space, or an environment, utilizing one or more lighting devices or apparatuses as disclosed herein.
In certain embodiments, lighting devices as described herein including multiple groups of one electrically activated (e.g., solid state) light emitters with peak wavelengths in the visible range. In certain embodiments, multiple electrically activated (e.g., solid state) emitters are provided, with groups of emitters being separately controllable relative to one another. In certain embodiments, one or more groups of solid state emitters as described herein may include at least a first LED comprising a first LED peak wavelength, and include at least a second LED comprising a second LED peak wavelength that differs from the first LED peak wavelength by at least 20 nm, or by at least 30 nm. In such a case, each of the first wavelength and the second wavelength is preferably within the visible range.
In certain embodiments, control of one or more solid state emitter groups or sets may be responsive to a control signal (optionally including at least one sensor arranged to sense electrical, optical, and/or thermal properties and/or environmental conditions), and a control system may be configured to selectively provide one or more control signals to at least one current supply circuit. In various embodiments, current to different circuits or circuit portions may be pre-set, user-defined, or responsive to one or more inputs or other control parameters.
In certain embodiments, each set of solid state light emitters comprises at least one electrostatic discharge protection element in electrical communication therewith.
In certain embodiments, multiple solid state emitters (e.g., LEDs) arranged to emit similar or different peak wavelengths are arranged on a common substrate, with different individual emitters or sets of emitters being separately controllable from other individual emitters or sets of emitters. Emitters having similar output wavelengths may be selected from targeted wavelength bins. Emitters having different output wavelengths may be selected from different wavelength bins, with peak wavelengths differing from one another by a desired threshold (e.g., at least 20 nm, at least 30 nm, at least 50 nm, or another desired threshold).
In certain embodiments, one or more sets of solid state emitter includes at least one BSY or white emitter component (including a blue solid state emitter arranged to stimulate emissions of a yellow lumiphor) and at least one red emitter (e.g., a red LED and/or a LED (e.g., UV, blue, cyan, green, etc.) arranged to stimulate emissions of a red lumiphor). Addition of at least one red emitter may be useful to enhance warmth of the BSY or white emissions and improve color rendering, with the resulting combination being termed BSY+R or warm white. In certain embodiments, red and BSY components may be separately controlled, as may be useful to adjust color temperature and/or to maintain a desired color point as temperature increases. In various embodiments, BSY components and red components may be controlled together in a single group or set, or may be aggregated into separate groups or sets that are separately controlled. One or more supplemental solid state emitters and/or lumiphors of any suitable color (or peak wavelength) may be substituted for one or more red light-emitting components, or may be provided in addition to one or more red light-emitting components. In certain embodiments, a blue LED may be arranged to stimulate emissions of both yellow and red phosphors, to yield a BS(Y+R) emitter.
In certain embodiments, a solid state lighting device may include one or more groups or sets of BSY light emitting components supplemented with one or more supplemental emitters, such as long wavelength blue, cyan, green, yellow, amber, orange, red or any other desired colors. Presence of a cyan solid state emitter (which is preferably independently controllable) is particularly desirable in certain embodiments to permit adjustment or tuning of color temperature of a lighting device, since the tie line for a solid state emitter having a ˜487 nm peak wavelength is substantially parallel to the blackbody locus for a color temperature of less than 3000K to about 4000K. Different groups of solid state light emitters are preferably controlled separately, such as may be useful to adjust intensity, adjust beam pattern, permit tuning of output color, permit tuning of color temperature, and/or affect dissipation of heat generated by the light emitting components.
In certain embodiments, solid state light emitters comprising a larger duty cycle may be positioned close to solid state emitters comprising a smaller duty cycle (e.g., with emitters comprising the largest duty cycle positioned closer to emitters comprising the smallest duty cycle than to any other emitters of a lighting device), such as may be beneficial to avoid perceptible spatial variations in light intensity and/or color, and/or may be beneficial for managing heat dissipation from a lighting device. In certain embodiments, a set of solid state light emitters having a smallest duty cycle of multiple sets of solid state light emitters is disposed proximate to a center of a substrate on or over which multiple sets of solid state emitters are arranged.
In one embodiments, a solid state lighting apparatus adapted to operate with alternating current (AC) received from an AC power source may include: multiple sets of one or more solid state light emitters arranged on or supported by a substrate, wherein at least first and second sets of the multiple sets of solid state light emitters are configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, and wherein the first and second sets of the multiple sets of solid state light emitters comprise different duty cycles; and wherein at least one solid state light emitter of the first set of solid state light emitters comprises a largest duty cycle of the different duty cycles and is arranged closer in proximity to at least one solid state emitter of the second solid state light emitter set comprising a smallest duty cycle of the different duty cycles than in proximity to any other solid state light emitter of the multiple sets of solid state light emitters. In certain embodiments, the multiple sets of solid state light emitters may include at least three different sets of solid state light emitters adapted to be activated and/or deactivated at different times relative to one another.
In certain embodiments, multiple sets of solid state light emitters that are configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle are configured to operate preferably within 15 percent, more preferably within 10 percent, more preferably within 5 percent, and more preferably within 3 percent, of a root mean square (RMS) voltage of the AC power source. In certain embodiments, the AC power source has frequency of 16.7 Hz, 50 Hz, 60 Hz, or 400 Hz, or any intermediate value between two or more of the foregoing frequency values. In certain embodiments, the AC cycle comprises a substantially sinusoidal waveform cycling between positive and negative voltages. In certain embodiments, the AC power source has a nominal RMS voltage of at least about 100V, such as including approximate values of 40V, 90V, 110V, 120V, 170V, 220V, 230V, 240V, 277V, 300V, 480V, 600V higher voltages, or any approximate or subset of voltage as previously recited. Operation of solid state light emitters at elevated voltages contradicts the traditional practice of converting power received from an AC source to substantially lower voltage DC power using an AC/DC converter in order to power solid state emitters (e.g., LEDs).
In certain embodiments, an AC voltage signal supplied to a lighting apparatus as described herein may include single phase AC voltage signal. In other embodiments the AC voltage signal may be obtained from multiple leads of a three phase AC voltage signal. Accordingly, the AC voltage signal can be provided from higher voltage AC voltage signals, regardless of the phase type. For example, in some embodiments of the present subject matter, the AC voltage signal can be provided from a three phase 600 VAC signal. In still further embodiments of the present subject matter, the AC voltage signal can be a relatively low voltage signal, such as approximately 12 VAC.
In certain embodiments, a lighting apparatus as described herein receives an AC input signal from an AC power source via an AC power cord arranged to plug into a conventional wall receptacle, with one end of the power cord comprising a two- or three-conductor male plug, and the other end of the power cord terminating in or on the lighting apparatus.
In certain embodiments, a lighting apparatus as described herein is devoid of any AC-to-DC converter in electrical communication between the AC power source and multiple sets (e.g., disposed in an array) of solid state light emitters. In certain embodiments, a lighting apparatus as described herein comprises at least one current diversion circuit (or multiple current diversion circuits in certain embodiments) arranged in electrical communication between an AC source and multiple sets of solid state light emitters. In certain embodiments, a lighting apparatus as described herein comprises at least one current limiting circuit (or multiple current limiting circuits in certain embodiments) arranged in electrical communication between an AC source and multiple sets of solid state light emitters. In certain embodiments, a lighting apparatus as described herein comprises at least one driving circuit (or multiple driving circuits in certain embodiments) arranged in electrical communication between an AC source and multiple sets of solid state light emitters. In certain embodiments, a lighting apparatus as described herein comprises at least one rectifier bridge (or multiple rectifier bridges in certain embodiments) arranged in electrical communication between an AC source and multiple sets of solid state light emitters.
In certain embodiments, a lighting apparatus as described herein includes multiple sets of solid state light emitters that are configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, and each set of the multiple sets comprises at least a first solid state light emitter of a first color and at least a second solid state light emitter of a second color that is different than the first color. In certain embodiments, each set of the multiple sets comprises at least two solid state light emitters of a first color. In certain embodiments, each set of the multiple sets of solid state emitters is adapted to emit one or more of the same color(s) of light (e.g., to emit one or more peak wavelengths that coincide among multiple sets of emitters). In certain embodiments, each set of the multiple sets of solid state emitters is adapted to emit one or more color(s) of light that differ relative to one another. (e.g., with each set of solid state emitters emitting at least one peak wavelength that is not emitted by another set of solid state emitters).
In certain embodiments, a lighting apparatus as described herein includes multiple sets of solid state light emitters that are configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, and the lighting apparatus comprises an output of preferably at least about 70 lumens per watt (LPW), more preferably at least about 80 LPW, more preferably at least about 90 LPW, and still more preferably at least about 100 LPW. Preferably, one or more of the foregoing LPW thresholds are attained for emissions having at least one of a cool white color temperature and a warm white color temperature. Preferably, white emissions have x, y color coordinates within four MacAdam step ellipses of a reference point on the blackbody locus of a 1931 CIE Chromaticity Diagram. In certain embodiments, such a reference point on the blackbody locus may have a color temperature of preferably less than or equal to 5000 K, more preferably less than or equal to 4000 K, more preferably less than or equal to 3500 K, or more preferably less than or equal to 3000 K. In certain embodiments, combined emissions from a lighting apparatus as described herein embody at least one of (a) a color rendering index (CRI Ra) value of at least 85, and (b) a color quality scale (CQS) value of at least 85.
In certain embodiments, a lighting apparatus as described herein includes an array of solid state light emitters arranged on or supported by a substrate, with the array including a plurality of solid state light emitter sets each comprising multiple solid state emitters, wherein multiple sets of solid state light emitters are configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, and within the array, at least one solid state light emitter of a first solid state light emitter set is arranged closer to at least one solid state emitter of a second solid state light emitter set than to any other solid state light emitter of the first solid state light emitter set. Such placement may be beneficial to avoid or reduce perceptible spatial variations in light intensity and/or color, and/or may be beneficial for managing heat dissipation from a lighting device. In certain embodiments, the multiple sets of solid state light emitters include at least two sets having different duty cycles (e.g., including a largest duty cycle and a smallest duty cycle). In certain embodiments, at least a majority of solid state light emitters comprising the smallest duty cycle are arranged in a central region of a substrate, and at least a majority of solid state light emitters comprising the largest duty cycle are arranged in a peripheral region of the substrate.
In certain embodiments, a lighting apparatus as described herein includes multiple sets of solid state light emitters that are configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, wherein, for a majority of solid state light emitters of a first solid state emitter set, each solid state light emitter of the majority of solid state light emitters is arranged closer to at least one solid state emitter of a second solid state light emitter set than to any other solid state light emitter of the first solid state light emitter set.
In certain embodiments, a lighting apparatus as described herein includes an array of solid state light emitters arranged on or supported by a substrate, with the array including a plurality of solid state light emitter sets each comprising multiple solid state emitters, wherein at least two different solid state light emitter sets of the plurality sets are adapted to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, wherein the at least two different solid state light emitter sets comprise different duty cycles, wherein the array comprises multiple solid state light emitters distributed across a central portion of the substrate, and comprises multiple solid state light emitters distributed across a peripheral portion of the substrate, and wherein the central portion comprises more solid state light emitters than the peripheral portion. In certain embodiments, the central portion of the substrate comprises less than or equal to about 65%, less than or equal to about 50%, less than or equal to about 40%, less than or equal to about 30%, less than or equal to about 15%, or less than or equal to about 10% of a total surface area of one face of the substrate. In certain embodiments, the peripheral portion circumscribes the central portion of the substrate. In certain embodiments, the central portion and the peripheral portion in combination comprise at least one of the following: concentric circles, concentric squares, concentric rectangles, or other concentric polygonal shapes of the same type.
In certain embodiments, a first solid state light emitter set of the at least two different solid state emitter sets comprises a smallest duty cycle of the different duty cycles, a second solid state light emitter set of the at least two different solid state emitter sets comprises a largest duty cycle of the different duty cycles, at least a majority of solid state emitters of the first solid state light emitter set is disposed in the central portion of the substrate, and at least a majority of solid state emitters of the second solid state light emitter set is disposed in the peripheral portion of substrate. In certain embodiments, a central portion of a substrate of a solid state lighting apparatus contains solid state emitters having a greater aggregated light emission area than a peripheral portion of the substrate. In certain embodiments, a plurality of solid state light emitter sets comprises at least three different solid state light emitter sets arranged to be activated and/or deactivated at different times relative to one another.
In certain embodiments, a lighting apparatus includes an array of solid state light emitters arranged or supported by a common substrate and including a plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, wherein the array is distributed across a region of the substrate, and wherein, for each set of the solid state light emitter sets, the multiple solid state light emitters are symmetrically arranged within or along the region. In certain embodiments, for each solid state light emitter set, the multiple solid state light emitters are arranged with azimuthal or rotational symmetry within or along the region. In certain embodiments, for each solid state light emitter set, the multiple solid state light emitters are arranged with lateral symmetry within or along the region.
In certain embodiments, a lighting apparatus includes an array of solid state light emitters arranged or supported by a common substrate and including a plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, wherein the lighting device comprises at least one of the following features: (a) at least one solid state light emitter set of the plurality of solid state light emitter sets is arranged to emit at least one peak wavelength that differs by at least 30 nm from at least one peak wavelength emitted by at least one other solid state light emitter set of the plurality of solid state light emitter sets; and (b) at least one solid state light emitter set of the plurality of solid state light emitter sets is arranged to emit a first peak wavelength and to emit a second peak wavelength that differs from the first peak wavelength by at least 30 nm. In certain embodiments, both of the foregoing features (a) and (b) may be present. In certain embodiments, at least two different solid state emitter sets comprise different duty cycles relative to one another, or at least three different solid state light emitter sets arranged to be activated and/or deactivated at different times relative to one another.
In certain embodiments, a first solid state light emitter set includes a plurality of LED chips adapted to generate peak emissions in a blue range and arranged to stimulate at least one phosphor adapted to generate peak emissions in a yellow range or a green range, and a second solid state light emitter set includes a plurality of LED chips adapted to generate peak emissions in an orange range or a red range.
In certain embodiments, color temperature of aggregated emissions of a lighting apparatus adapted to operate with alternating current (AC) received from an AC power source may be adjusted by adjusting duty cycle of one or more sets of multiple sets of solid state emitters that are each separately arranged to emit white light but at different color temperatures.
In certain embodiments, a lighting apparatus includes an array of solid state light emitters arranged or supported by a common substrate and including a plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least three different solid state light emitter sets of the plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, and wherein each solid state light emitter set of the at least three different solid state light emitter sets is independently arranged to emit light having x, y color coordinates within four MacAdam step ellipses of a reference point on the blackbody locus of a 1931 CIE Chromaticity Diagram and having a color temperature that differs by at least 400 K relative to a color temperature of each other solid state light emitter set of the at least three different solid state light emitter sets. Utilization of multiple sets of solid state emitters with each set arranged to generate white light of different color temperatures permits color temperature of the aggregated emissions to be adjusted by varying the duty cycle of the respective solid state emitter sets. In certain embodiments, a control element may be arranged to permit adjustment of duty cycle of each solid state light emitter set of the at least three different solid state light emitter sets, and thereby permit adjustment of color temperature. In certain embodiments, at least three different solid state light emitter sets in combination are arranged to emit light having x, y color coordinates within two MacAdam step ellipses of a reference point on the blackbody locus of a 1931 CIE Chromaticity Diagram.
In certain embodiments, beam patterns output from a solid state lighting device may be adjusted by adjusting duty cycles of different solid state light emitter sets, preferably without use of any mechanical elements. In certain embodiments, different sets of solid state light emitters are arranged differently with respect to at least one reflector and/or at least one optical element to permit such beam pattern adjustment.
In certain embodiments, a lighting apparatus includes an array of solid state light emitters arranged on or supported by a body structure and including a plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle; at least one reflector and/or at least one optical element arranged to receive emissions from the plurality of solid state light emitter sets, and arranged to affect a beam pattern generated by the lighting device; and a control element arranged to permit adjustment of duty cycle of each solid state light emitter set of the at least two solid state light emitter sets, and thereby permit adjustment of said beam pattern. In certain embodiments, both at least one reflector and at least one optical element may be provided. In certain embodiments, a first reflector or first reflector portion may be arranged to receive emissions from a first solid state light emitter set of the plurality of solid state light emitter sets, and a second reflector or second reflector portion may be arranged to receive emissions from a second solid state light emitter set of the plurality of solid state light emitter sets. In certain embodiments, a first optical element portion may be arranged to receive emissions from a first solid state light emitter set, and a second optical element portion may be arranged to receive emissions from a second solid state light emitter set.
In certain embodiments, a lighting apparatus is adapted to operate with alternating current (AC) received from an AC power source, and the lighting apparatus includes: a first array of solid state light emitters arranged on or supported by a first substrate and including a first plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the first plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle; a second array of solid state light emitters arranged on or supported by a second substrate and including a second plurality of solid state light emitter sets each comprising multiple solid state light emitters, wherein at least two different solid state light emitter sets of the second plurality of solid state light emitter sets are arranged to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle; and a support plate comprising a plurality of substrate mounting regions including a first substrate mounting region arranged to receive the first substrate and including a second substrate mounting region arranged to receive the second substrate. In certain embodiments, the first substrate may include a first circuit board (e.g. a PCB, including but not limited to a metal core PCB), and the second substrate may include a second printed circuit board. In certain embodiments, the support plate may include a heatsink in conductive thermal communication with the first substrate and the second substrate. Such heatsink may include multiple fins arranged to dissipate heat into a heat exchange apparatus or an ambient environment (e.g., an ambient air environment). In certain embodiments, the support plate may include a reflector arranged to reflect emissions from at least some emitters of the first array of solid state emitters, and to reflect emissions from at least some emitters of the second array of solid state emitters. In certain embodiments, the first substrate mounting region may include a first plurality of electrical conductors or contacts arranged in electrical communication with the first substrate and the first array of solid state emitters, and the second substrate mounting region may include a second plurality of electrical conductors or contacts arranged in electrical communication with the second substrate and the second array of solid state emitters. In certain embodiments, the first substrate mounting region may include a first socket, and the second substrate mounting region may include a second socket.
Various illustrative features are described below in connection with the accompanying figures.
The LED driver circuit 12 can be coupled to an AC voltage power source, which can provide an alternating electrical signal (current and voltage) to at least one LED string circuit 14, and other circuits included in the solid state lighting apparatus 10, to cause light to be emitted from solid state lighting apparatus 10. The at least one LED string circuit 14 can comprise multiple solid state light emitters, such as LED chips, preferably arranged as multiple groups or sets of LEDs, wherein each group or set is preferably separately controllable relative to each other group or set. In certain embodiments, LED string circuit 14 can comprise a multi-dimensional (e.g., two-dimensional) array of LED chips. The LED chips can be optionally arranged in one or more mutually exclusive groups, segments, or sets of LED chips. In one aspect, LED string circuit 14 comprises an array of LED chips arranged in mutually exclusive sets of one or more (preferably multiple) LED chips.
It will be appreciated that various embodiments described herein can make use of the direct application of AC voltage to apparatus 10 (e.g., from an outside power source, not shown) without the inclusion of an “on-board” switched mode power supply. That is, various embodiments relate to devices that are devoid of any AC-to-DC converter in electrical communication between the AC power source (not shown) and multiple groups of LED chips. In certain embodiments, a LED driver circuit 12 can output current including a rectified AC waveform to LED string circuit 14 to generate acceptable light output from the lighting apparatus 10. It can further be appreciated that solid state lighting apparatus 10 can be utilized in light bulbs, lighting devices, and/or lighting fixtures of any suitable type, such as, for example and without limitation, the various lighting devices illustrated in
In certain embodiments, a LED driver circuit 12 can include one or more of the following: components used to rectify the AC voltage signal, components to provide an electrical current source to at least one LED string circuit 14, components for at least one current diversion circuit, components for at least one current limiting circuit (e.g., to limit the amount of current passing through at least one LED chip and/or set of LED chips in LED string circuit 14), and at least one energy storage device, such as a capacitor 32 (such as shown in
LED string circuit 14 can include a plurality of “chip-on-board” (COB) LED chips and/or packaged LED chips that can be electrically coupled or connected in series or parallel with one another and mounted on a portion of substrate 16. In certain embodiments, COB LED chips can be mounted directly on portions of substrate 16 without the need for additional packaging. In certain embodiments, LED string circuit 14 can make use of packaged LED chips in place of the COB LED chips. For example, in certain embodiments, LED string circuit 14 can comprise serial or parallel arrangements of XLamp XM-L High-Voltage (HV) LED packages available from Cree, Inc. of Durham N.C.
In certain embodiments, a solid state lighting apparatus 10 can comprise a relatively small form factor board or substrate 16, which can be directly coupled to an AC voltage signal and can provide a rectified AC voltage signal to string circuit 14 without the use of an on-board switched mode power supply. COB LED chips and/or LED packages within circuit 14 can be electrically connected in serial arrangements, parallel arrangements, or combinations thereof.
In certain embodiments, a substrate 16 can be provided in any relatively small form factor (e.g., square, round, non-square, non-round, symmetrical, and/or asymmetrical) such as those described herein in reference to
In other embodiments, a substrate 16 may comprise a larger form factor, such as may be suitable for replacement of elongated fluorescent tube-type bulbs or replacement of fluorescent light fixtures.
Current diversion circuit 22 can be configured to operate responsive to a bias state transition of those sets of respective LED chips or LED packages across which current diversion circuit 22 is coupled. In certain embodiments, LED chips or packages within string circuit 14 can be incrementally activated and de-activated responsive to the forward biasing of LED sets as a rectified AC voltage is applied to LED string circuit 14. For example, current diversion circuit 22 can include transistors configured to provide respective controllable current diversion paths around certain LED sets disposed between the selected nodes to which current diversion circuit 22 is coupled. Such transistors can be turned on or off by the biasing transitions of LED sets which can be used to affect the biasing of the transistors. Current diversion circuits 22 operating in conjunction with a LED string circuit 14 are further described, for example, in commonly assigned co-pending U.S. application Ser. No. 13/235,127, the entirety of which is incorporated by reference herein. Current diversion circuit 22 can activate and/or deactivate different LED sets at different times relative to one another during a portion of an AC cycle as explained further below. In certain embodiments, and as explained below, solid state lighting apparatus 10 can comprise multiple LED sets having different duty cycles. In various embodiments, multiple LED sets can be provided and strategically positioned over portions of substrate 16 to reduce perceived flicker, perceived color shifts, and/or perceived (e.g., positional or directional) flux variation during activation and/or deactivation of the respective LEDs.
As further shown in
In certain embodiments, some or all of the components described in reference to
In certain embodiments, solid state lighting apparatus 10 can may include one or more current diversion circuits 22 coupled to portions of string circuit 14 alone without use of a current limiter circuit 30 (
In certain embodiments, apparatuses 10 as described herein can provide at least about 700 lumens (lm), or provide approximately 700 lumens (lm) to approximately 820 lm, an efficacy ranging from between about 71 LPW and about 80 LPW at cool or warm white color temperatures. It will be understood that in certain embodiments, however, that greater output may be achieved by, for example, increasing the number of LED chips and/or packages or by increasing the current signal or level used to drive the LED chips or packages.
It will be understood that current limiter circuit 30 and capacitor 32 according to certain embodiments can advantageously reduce flicker which may otherwise result from the AC voltage provided directly to solid state light emitters of solid state lighting apparatus 10. For example, capacitor 32 can be used to store energy (e.g., near peak voltage) and use that stored energy to drive portions of LED string 14 (e.g., one or more LED sets) when the AC voltage magnitude is less than what may be required to forward bias the LED chips or packages in string circuit 14. Still further, current limiter circuit 30 can be configured to direct current to capacitor 32 so that energy is stored therein or configured to discharge the charge in capacitor 32 through LED string circuit 14. Although
In certain embodiments, the components shown in
Where multiple LED chips 40 are used, chips 40 within a given set S1, S2, . . . , SN can be arranged in series, parallel, and/or combinations thereof. In certain embodiments, each LED set S1, S2, . . . , SN can be configured to be activated and/or deactivated at different times. In certain embodiments, LED sets S1, S2, . . . , SN can be sequentially activated and deactivated in the reverse order. Notably, LED sets S1, S2, . . . , SN can be strategically arranged on portion of substrate 16 such that color and light output from apparatus 10 can be consistently maintained (e.g., with no perceived flicker, perceived color shift, and/or perceived positional or directional flux variation) during activation and/or deactivation of different LED sets S1, S2, . . . , SN at different times. In certain embodiments, each LED set S1, S2, . . . , SN can comprise a plurality of LED chips arranged in one or more arrays comprised of serial and/or parallel arrangements.
In certain embodiments, LED chips 40 of each LED set S1, S2, . . . , SN can comprise one or more chips of the same color (e.g., S1, S2, . . . , SN can be the same color) or different colors (e.g., S1, S2, . . . , SN can each be a different color). In certain embodiments, one or more LED sets S1, S2, . . . , SN can comprise differently colored LED chips 40 within that set (e.g., intra-set). In certain embodiments each LED set S1, S2, . . . , SN can comprise the same color combination as other sets (e.g., S1, S2, . . . , SN can each have a blue, red, and green chip) or at least one set can have a color combination that differs from at least one other set (e.g., S1 can have a blue, red, and green chip and S2 can have a blue shifted yellow (BSY), cyan, and amber chip). In certain embodiments, multiple LED chips 40 having the same and/or any different combinations of color, wavelength, color temperature, and/or brightness may be provided.
As illustrated in
In certain embodiments, electrical power or signal can be provided to LED string 14 by a driver circuit 20 comprising a rectifier circuit 20 that is configured to be coupled to an AC power source 42 and to produce a rectified voltage VR and current IR therefrom. In certain embodiments, rectifier circuit 20 can comprise four diodes which prevent current from flowing in the negative direction, thereby producing a rectified AC waveform (e.g., 50,
In certain embodiments, apparatus 10 may include respective current diversion circuits 22-1, 22-2, . . . , 22-N connected to respective nodes and/or LED sets S1, S2, . . . , SN of string circuit 14. Current diversion circuits 22-1, 22-2, . . . , 22-N can be configured to provide current paths that bypass respective LED sets S1, S2, . . . , SN. The current diversion circuits 22-1, 22-2, . . . , 22-N can each include at least one transistor Q1 configured to provide a controlled current path that may be used to selectively bypass one or more LED sets S1, S2, . . . , SN. Transistors Q1 can be biased using one or more second transistors Q2, one or more resistors R1, R2, . . . , RN and/or one or more diodes D. Second transistors Q2 can be configured to operate as diodes, with base and collector terminals connected to one another. Differing numbers of diodes D can be connected in series with second transistors Q2 in respective ones of current diversion circuits 22-1, 22-2, . . . , 22-N, such that the base terminals of current path transistors Q1 in the respective current diversion circuits 22-1, 22-2, . . . , 22-N can be biased at different voltage levels. Resistors R1, R2, . . . , RN can limit base currents for current path transistors Q1. Current path transistors Q1 of the respective current diversion circuits 22-1, 22-2, . . . , 22-N can turn off at different emitter bias voltages, which can be determined by a current flowing through apparatus resistor R0. Accordingly, current diversion circuits 22-1, 22-2, . . . , 22-N can be configured to operate in response to bias state transitions of the LED sets S1, S2, . . . , SN as the rectified voltage VR increases and decreases such that the LED sets S1, S2, . . . , SN can be incrementally and selectively activated and deactivated as the rectified voltage VR rises and falls. Current path transistors Q1 can be turned on and off as bias states of LED sets S1, S2, . . . , SN change.
In certain embodiments, string circuit 14, including serially connected LED sets S1, S2, . . . , SN, can also be coupled in series with current limiter circuit 30. In certain embodiments, current limiter circuit 30 can comprise a current mirror circuit, although current limiter circuits of any suitable type may be used. In certain embodiments, current limiter circuit 30 can be connected at nodes 44 and 46 of apparatus 10 as shown in
In certain embodiments, current limiter circuit 30 can include first and second transistors Q1, Q2 and one or more resistors R1, R2, R3 connected in a current mirror configuration. The current mirror circuit can provide a current limit of approximately (VLED−0.7)/(RI+R2)×(R2/R3). A voltage limiter circuit 48, e.g., a Zener diode, can also be provided to limit the voltage developed across the one or more storage capacitors 32. In this manner, the one or more storage capacitors 32 can be alternately charged via the driver circuit 12 comprised of the rectifier circuit and discharged via string circuit 14 of serially connected LED sets S1, S2, . . . , SN, which may provide more uniform illumination. In certain embodiments, current limiter circuit 30 can also be coupled to a LED set SX, which is included among the plurality of LED sets S1, S2, . . . , SN in string circuit 14. It is understood that LED set SX can include single LED chips 40 or multiple LED chips 40 coupled in parallel and/or series with one another. As noted earlier, each LED set S1, S2, . . . , SN can be mutually exclusive and coupled in series with one another.
In certain embodiments, each LED set can be “on” or active for a given time portion or time interval. For example, first LED set S1 is active for a first time interval Δt1 which is longer than second and third time intervals Δt2 and Δt3 that are associated with second and third LED sets S2 and S3, respectively. As
In certain embodiments, current (generally designated 52 in
In various embodiments, apparatuses described herein can be configured to activate and/or deactivate different LED sets at different and/or overlapping times to avoid perceptible flicker and to maintain color point (e.g., turn on/off the right color combinations to maintain a constant color point). For illustration purposes, only three LED sets have been illustrated as being activated and/or deactivated twice during one cycle of an input AC waveform; however, in certain embodiments, any suitable number of LED sets (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10 or more LED sets) may be provided. In certain embodiments, LED sets may be activated and/or deactivated more than twice per cycle, and any suitable AC input frequency may be used to achieve a desired frequency of activation and/or deactivation for one or more LED sets of a solid state lighting apparatus.
In certain embodiments, LED sets are activated and deactivated at least 50, 60, 80, 100, 120, 160, 200, 240, or more time per second. Any suitable frequency of activation and deactivation of one or more LED sets be used to reduce and/or eliminate perceived flicker, perceived color shift, and/or perceived differences in luminous flux. In certain embodiments, LED sets S1, S2, . . . , SN can also comprise overlapping duty cycles, where different LED sets can be activated (e.g., “on”) and/or deactivated (e.g., “off”) during portions of the same cycle and/or fraction of time.
In certain embodiments, the multiple sets can be configured to operate within (+/−) approximately 15 percent (%) of a root mean square (RMS) voltage VRMS of the AC power source. For illustration purposes in
In certain embodiments, relative numbers of solid state light emitters (e.g., LEDs) in different LED sets may be adjusted to enhance efficacy, with at least two different sets of LEDs in a single device embodying different numbers of LEDs. The inventors have discovered that in order to enhance efficacy, it is desirable to pick the LED counts in each LED set (e.g., string) such that n1>=n2>=n3>= . . . nX, were n1 is the number of LEDs in the set that are on the longest (i.e., having the largest duty cycle), n2 is the number of LEDs in the set that is on the next longest (i.e., having the second largest duty cycle), n3 is the number of LEDs in the set that is on the next longest (i.e., having the third largest duty cycle), and so on, subject to the constraint that n1+n2+n3 . . . nX=total, where Ntotal is the total number of LED desired to be included in the lighting apparatus. Accordingly, in a solid state lighting apparatus adapted to operate with alternating current (AC) received from an AC power source, including multiple sets of solid state light emitters (e.g., arranged on or supported by a substrate), wherein at least first and second sets of the multiple sets of solid state light emitters are configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, and wherein the at least first and second sets of the multiple sets of solid state light emitters comprise different duty cycles, the apparatus preferably includes at least one of the following features (i) and (ii): (i) the first set of solid state light emitters comprises a largest duty cycle of the different duty cycles and consists of a greater number of solid state light emitters than any other set of the multiple sets of solid state light emitters; and (ii) the second set of solid state light emitters comprises a smallest duty cycle of the different duty cycles and consists of a smaller number of solid state light emitters of the multiple sets of solid state light emitters. In certain embodiments, at least a third set of solid state emitters (e.g., having a duty cycle intermediate between the first set and the second set) may be provided, with the third set of solid state emitters preferably having a number of solid state emitters intermediate (a) the number of solid state emitters contained in the first set and (b) the number of solid state emitters contained in the second set.
In certain embodiments, LED chip colors may be uniform (e.g., the same) within a set, but may differ from set to set. As illustrated in
In certain embodiments, any combination and/or variation of one or more color of LED chips intra-set and/or inter-set are contemplated herein, whether provided as combinations of LED chip and/or LEDs in combination with differently colored lumiphors (e.g. phosphors). Certain embodiments may utilize LED chips that can individually be adapted to generate peak emissions and/or a peak wavelength in a blue range, a green range, cyan, a red range, red-orange, orange, amber, and/or in a yellow range light upon activation by electrical current. In certain embodiments, LED chips can be used alone or in combination with one or more lumiphors (e.g., phosphors) configured to generate peak emissions in a red range, a green range, a blue range, a yellow range, or any other desired color range upon activation or stimulation by light from one or more LED chips. At least one LED set can be adapted to emit at least one peak wavelength that differs by at least 30 nm from at least one peak wavelength emitted by at least one other LED chip in at least one other LED set. In further aspects, at least one LED set can be adapted to emit a first peak wavelength and to emit a second peak wavelength that differs from the first peak wavelength by at least 30 nm. Notably, driver circuit 12 can be configured to activate and/or deactivate different sets of LED chips without a perceptible shift in color point, color temperature, and/or without perceptible flicker. In part, this can be accomplished by intra-set and inter-set color selection, and/or by relative positioning of LED sets and/or their constituent LEDs.
In certain embodiments, during activation and deactivation of one or more LED sets, a color point of a lighting apparatus can be maintained (e.g., without a perceptible color shift). This can also be achieved in part by board or substrate 16 designs, and/or relative placement, LED chips having different colors and/or duty cycles. For example, as described below in
In certain embodiments, a lighting apparatus may include multiple sets of solid state emitters, wherein various sets include intra-set emitter color variation, together with variation in color between sets (inter-set color variation).
In certain embodiments, emitter sets separately arranged to generate white emissions of different color temperatures may be combined in a lighting apparatus to permit color temperature of aggregated emissions to be varied.
In certain embodiments, lighting apparatuses described herein can comprise multiple sets of solid state light emitters, such as and without limitation, LED chips. In addition, different LED sets can comprise different ratios of differently colored LED chips, for example, different ratios of BSY chips, B(Y+R) chips, red chips, green chips, cyan chips, and/or combinations thereof, such that some activated sets can compensate for and/or maintain an overall color of apparatus 10 when other LED sets deactivate. Still referring to color choice for one or more LED chips and/or LED sets, three different LED emitter sets can be independently arranged to emit light having x, y color coordinates within approximately four MacAdam step ellipses of a reference point on the blackbody locus of a 1931 CIE Chromaticity Diagram and have a color temperature that differs by at least 400 K relative to a color temperature of each other LED set of the at least three different LED sets. More than three LED sets are contemplated.
Different LED sets can be arranged over different portions of substrate 16. IN certain embodiments, one or more LED chips of one LED set can be physically intermingled, adjacent, and closely packed proximate one or more other LED chips of one or more other LED sets. In certain embodiments, LED chips of different sets form a singular, uniform array of LED chips. For example, and as
In certain embodiments, LED chips (e.g., LED1, LED2, . . . , LEDN) of first LED set S1 can be adjacent and/or closest to LED chips of second LED set S2. LED chips of second LED set S2 can be disposed between LED chips of first LED set S1 and third LED set S3. As known in the art, LED chips heat up during operation. Thus, in certain embodiments, LED chips of each LED set can comprise a staggered and/or physically intermingled arrangement for spreading heat across different portions of substrate 16 to improve heat dissipation therefrom 16 and/or to prevent hot spots from occurring in concentrated areas or regions of substrate 16, such as regions directly under the LED chips. In certain embodiments, LED chips of some LED sets can be intermingled and/or positioned adjacent LED chips of other LED sets in any suitable method, for example, by overlapping strings of LED chips, using flex circuitry components, and/or cross-circuitry components such as embedded electrical traces, conductive vias, and jumper elements to transfer current through and/or across portions of substrate 16 and into respective LED chips of different LED sets.
As shown in
Positioning emitters having smaller duty cycles closer to a center of a substrate may aid in thermal dissipation and in promoting longevity of solid state emitters, by reducing thermal load (and reducing hot spots) proximate to the center of the substrate. Second LED set S2, having the second longest duty cycle and on for the second longest (or shortest) time Δt2 (
In certain embodiments, first, second, and third portions 62, 64, and 66, respectively, can also comprise concentric shapes that are substantially square, rectangular, or non-circular. In other aspects, the portions can be non-concentric, for example, parallel strips or other adjacent portions of substrate 16. LED chips of first LED set S1 can be adjacent LED chips of both second LED set S2 and third LED set S3 to form a pattern or array. Any arrangement of LED sets S1, S2, . . . , SN over portions of substrate 16 is contemplated. In certain embodiments, substrate 16 can comprise only two or more than three portions for receiving only two or more than three sets of LED chips. In certain embodiments, the number of substrate portions or regions corresponds to the number of LED sets.
In certain embodiments, traces 68 and 70 can comprise crossing circuitry components utilizing electrically conductive vias or through-holes adapted to convey electrical current internally and/or to different surfaces of the substrate 16. In certain embodiments, portions of first and second traces 68 and 70 can indirectly overlap, and at least one LED chip of first LED set S1 can be disposed proximate at least one LED chip of third LED set S3. In certain embodiments, at least one insulating material (e.g., an insulating layer of substrate 16) can be physically arranged between overlapping portions of traces 68 and 70 such that electrical traces remain electrically insulated from each other. In certain embodiments, traces 68 and 70 can comprise overlapping and/or braided portions of electrically insulated flexible conductors or circuit-containing substrates (e.g., circuit boards). In certain embodiments, third LED set S3 can be disposed along portions of a third trace 72, which can be disposed proximate a center line or center portion of substrate 16. In certain embodiments, LED chips of first LED set S1 comprising a longest duty cycle can be positioned directly adjacent to, and/or closely packed with, LED chips of third LED set S3 comprising a shortest duty cycle. Any number of LED chips and/or LED sets can be used to place LED chips that are active the longest amount of time next to LED chips that are active the least amount of time to alleviate noticeable color shifts, flux variations, and/or flicker during operation. Such placement can also advantageously improve thermal management of lighting apparatuses disclosed herein by efficiently spreading heat across different regions and away from the center of substrate 16, and avoiding or reducing hot spots during operation
In certain embodiments, at least a portion of substrate 16 can comprise a MCPCB, such as a “Thermal-Clad” (T-Clad) insulated substrate material, available from The Bergquist Company of Chanhassen, Minn. A “Thermal Clad” substrate may reduce thermal impedance and conduct heat more efficiently than standard circuit boards. In certain embodiments, a MCPCB can also include a base plate on the dielectric layer, opposite the LED string circuit, and can comprise a thermally conductive material to assist in heat spreading. In certain embodiments, the base plate can comprise different material such as copper, aluminum or aluminum nitride. The base plate can have different thicknesses, such an in the range of 100 to 2000 μm. Substrate 16 can comprise any suitable material and any suitable thickness (e.g., approximately 0.5 mm to more than 5 mm as previously described).
In certain embodiments, a solid state lighting apparatus 80 can comprise a string circuit of multiple solid state light emitters, such as LED chips 82, arranged in multiple mutually exclusive sets. In certain embodiments, each LED chip 82 can be directly disposed over portions of substrate 16 (e.g., COB LED chips) or each LED chip 82 can be disposed in a LED package generally designated 84. In certain embodiments, LED package 84 can comprise a package submount 86 and an optional optical element 88. Optical element 88 can comprise a layer of silicone encapsulant or a glass or overmolded silicone lens. Submount 86 can comprise any suitable material, for example, a metal, plastic, ceramic, or combinations thereof. In certain embodiments, a submount 86 may include a ceramic based submount comprising alumina (Al2O3), or aluminum nitride AlN, however, any material is contemplated. In certain embodiments, a submount 86 can comprise a body structure including a reflector having multiple reflector portions adapted to affect a beam pattern generated by apparatus 80.
In certain embodiments, electrical traces and/or other circuitry components can be used to permit electrical communication with solid state light emitters arranged in multiple sets of LED chips 82 over submount 16. As described earlier, in certain embodiments each LED set can comprise one or more packaged or unpackaged LED chips 82 electrically connected in parallel. In certain embodiments, each LED set can be connected in series with other LED sets. In certain embodiments LED chips 82 can comprise the same color intra-set and/or inter-set. In certain embodiments, LED chips 82 can comprise different colors intra-set and/or inter-set. Any combination of intra- and inter-set colors, color points, and color temperatures are contemplated. In certain embodiments, current diversion circuits comprised of at least one transistor 90, resistor 92, and diode 94 can be arranged in parallel with each LED set to divert current about and thereby activate and/or deactivate the LED sets during portions of an AC cycle. Current diversion circuits can also comprise multiple transistors 90, resistors 92, and/or diodes 94. To reduce flicker and/or color shifting during activation and deactivation, LED sets can be placed such that LED chips that are “on” the most amount of time or can be directly adjacent LED chips that are “on” the least amount of time. Stated differently, LED chips having the largest duty cycle can be placed closer (e.g., directly adjacent in a closely packed array) to LED chips having a shorter duty cycle and, optionally the shortest duty cycle of multiple duty cycles. Such placement can also improve thermal management and reduce substrate 16 from accumulating hot spots during elevated operating temperatures.
In certain embodiments, solid state lighting apparatus 80 can comprise a rectifier circuit in the form of a rectifier bridge 96. Rectifier bridge 96 can comprise a portion of the drive circuit of apparatus 10 for supplying power to LED chips 82. An input connector 98 can receive AC signal directly from an AC power source (not shown). Rectifier bridge 96 can then convert the sinusoidal AC waveform into a rectified AC waveform without requiring an on-board switched mode power supply. Input connector 98 can comprise a housing having two inlets for receiving and mechanically and electrically coupling with two electrical wires (not shown) arranged to carry an AC input signal from an AC electrical power source. LED chips 82 can be activated and/or deactivated during different portions of the AC cycle. Solid state lighting apparatus 80 can also be modular in the fact that it can easily be mounted to and/or affixed within any suitable lighting fixture by insertion of attachment members (e.g., fasteners, screws, nails, etc.) into portions of attachment member receiving areas 100.
In certain embodiments, solid state lighting apparatus 80 can deliver approximately 70 LPW or more in select color temperatures, such as cool or warm white color temperatures (e.g., from approximately 2700 to 7000 K). In embodiments where COB LED chips are used, apparatus 80 can further comprise one or more optional optical elements and/or reflectors for being positioned over and/or cover portions of LED chips to affect the beam pattern generated by apparatus 80. In certain embodiments, at least one reflector can comprise more than one portion for receiving light from LED sets
In certain embodiments, one or more substrates (e.g., modules) bearing multiple sets of separately controllable LEDs as described herein may be affixed to a support plate or other superstructure (optionally including heat dissipating elements) arranged to receive the substrate(s). Such approach enables fabrication of a modular lighting device.
In certain embodiments, a lighting panel can further comprise attachment sockets 114 configured to receive modular solid state lighting apparatuses. In certain embodiments, sockets 114 can comprise flush, inset, or raised regions of panel 110 such that apparatuses 80 can be mechanically and/or be electrically connected by plugging electrical connectors into input connectors 98 (
In certain embodiments, lighting panels, lighting fixtures, and/or apparatuses described herein may comprise a control element or controller 116. In certain embodiments, controller 116 can be configured to store programs configured to control the selective activation and/or deactivation of different LED sets. In certain embodiments, controller 116 can be programmed such that each LED set switches on/off based upon on a different duty cycle. In certain embodiments, controller 116 can be programmed such that each LED set switches on/off based upon variables associated with voltage, time, AC cycle, duty cycles, and/or combinations thereof. In certain embodiments, controller 116 can be adapted to controllably switch and/or cycle different LED sets on and off based upon any suitable and/or different input variables and any combinations thereof. In certain embodiments, a user can program controller 116 using any desired input variable for selectively controlling activation and deactivation of LED sets within one or more apparatuses 80 disposed in or on panel 110. In certain embodiments, controller 116 can be adapted to permit adjustment of a duty cycle for each LED set of one or more LED sets, and thereby permit adjustment of overall perceived color temperature and/or a beam pattern generated by one or more apparatuses 80. In certain embodiments, a user can select different operating modes based upon desired color rendering and/or efficiency desired from lighting panel 110.
In certain embodiments lighting panel 110 can comprise thermal management members such as fins 118 and/or heatpipes (not shown) for improved spreading and/or dissipation of heat generated by solid state lighting apparatuses 80 disposed thereon.
As shown in
In certain embodiments, at least one solid state light emitter of a first set of solid state light emitters that comprises a largest duty cycle is arranged closer in proximity to at least one solid state emitter of a second solid state light emitter set that comprises a smallest duty cycle. As shown in
In certain embodiments as shown in
In certain embodiments, at least one solid state light emitter of a first solid state light emitter set is arranged closer to at least one solid state emitter of a second solid state light emitter set than to any other solid state light emitter of the first solid state light emitter set.
As shown in
In certain embodiments, portions different emitter sets may be dispersed in subgroups that with constituents arranged equidistantly and/or symmetrically relative to a center of a substrate of a light emitting apparatus.
In certain embodiments, multiple solid state light emitters are distributed across a peripheral portion of the substrate, and a central portion of the substrate comprises a larger number of solid state light emitters than a peripheral portion of the substrate (such that a majority of the emitters are arranged in the central portion).
As shown in
In certain embodiments, at least one reflector and/or at least one optical element arranged to receive emissions from multiple solid state light emitter sets adapted to operate with alternating current (AC) received from an AC power source and configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, wherein the light emitter sets are arranged to affect a beam pattern generated by a lighting device; and a control element is arranged to permit adjustment of duty cycle of the solid state light emitter sets to permit adjustment of a beam pattern output by a lighting device.
In certain embodiments, different reflectors and different optical elements may be associated with different groups of solid state emitters.
Although
In certain embodiments, to a solid state lighting apparatus adapted to operate with alternating current (AC) received from an AC power source, the lighting apparatus including: multiple substrate regions; and multiple sets of one or more solid state light emitters arranged on or supported by the multiple substrate regions, wherein at least first and second sets of the multiple sets of solid state light emitters are configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle, wherein the first and second sets of the multiple sets of solid state light emitters comprise different duty cycles; and wherein the lighting apparatus comprises at least one of the following features (i) to (iii): (i) a first substrate region of the multiple substrate regions includes one or more solid state light emitters of the first set of solid state light emitters and includes one or more solid state light emitters of the second set of solid state light emitters; and a second substrate region of the multiple substrate regions is non-coplanar with (and preferably non-parallel to) the first substrate region and includes one or more solid state light emitters of the first set of solid state light emitters and includes one or more solid state light emitters of the second set of solid state light emitters; (ii) at least one first solid state light emitter of the first set of solid state light emitters is arranged on a first substrate region of the multiple substrate regions that is substantially parallel to a first plane, at least one second solid state light emitter of the second set of solid state light emitters is arranged on a second substrate region of the multiple substrate regions that is substantially parallel to a second plane that is non-coplanar with the first plane but oriented less than 30 degrees apart from the first plane, and at least a portion of emissions of the at least one first solid state emitter are arranged to mix or overlap with at least a portion of emissions of the at least one second solid state emitter; and (iii) at least one first solid state light emitter of the first set of solid state light emitters is arranged on a first substrate region of the multiple substrate regions and is arranged to output a first beam centered in a first direction, and at least one second solid state light emitter of the second set of solid state light emitters is arranged on a second substrate region of the multiple substrate regions and is arranged to output a second beam centered in a second direction that is non-parallel to the first direction but oriented less than 30 degrees apart from the first direction. One, two, or three of the foregoing features (i) to (iii) may be present in a single apparatus. In certain embodiments, multiple substrate regions comprise different regions of a substantially continuous substrate. In certain embodiments, a substantially continuous substrate comprises a curved, concave, or convex surface including the different regions. In certain embodiments, multiple substrate regions comprise regions of different substrates. In certain embodiments, a support element may be arranged to support each substrate of the different substrates. In certain embodiments, a reflector may be arranged to reflect emissions of one or more solid state light emitters of the first set of solid state light emitters and arranged to reflect emissions of one or more solid state light emitters of the second set of solid state light emitter. In certain embodiments, a globe, diffuser, or optical element arranged to transmit and/or diffuse emissions of one or more solid state light emitters of the first set of solid state light emitters and arranged to transmit and/or diffuse emissions of one or more solid state light emitters of the second set of solid state light emitter. Such a globe, diffuser, or optical element may be arranged to bound a cavity containing the multiple sets of one or more solid state light emitters, and wherein a plurality of conductors conducting AC power are arranged within the cavity. In certain embodiments, a driving circuit including a rectifier bridge may be arranged within the cavity. In certain embodiments, a lumiphor support element may be spatially segregated from the multiple sets of one or more solid state emitters, and at least one lumiphor supported by the lumiphor support element, wherein the at least one lumiphor is arranged to be stimulated by emissions of at least some solid state light emitters of the multiple sets of solid state light emitters. In certain embodiments, multiple sets of solid state light emitters are configured to operate within 15 percent (%) of a root mean square (RMS) voltage of the AC power source. In certain embodiments, multiple sets of solid state light emitters comprise at least three different sets of solid state light emitters adapted to be activated and/or deactivated at different times relative to one another. In certain embodiments, each set of the multiple sets comprises at least a first solid state light emitter of a first color and at least a second solid state light emitter of a second color that is different than the first color. In certain embodiments, each set of the multiple sets comprises at least two solid state light emitters of a first color. In certain embodiments, the lighting apparatus is devoid of any AC-to-DC converter in electrical communication between the AC power source and the multiple sets of solid state light emitters.
In certain embodiments, as illustrated in
In some embodiments, substrate 2410 may be include multiple integrally formed panel portions 2430A to 2430F which may be bendable, flexible, pivotable, or otherwise movable along (or proximate to) the areas indicated in broken lines in
In certain embodiments, at least one control circuit element 2450 (such as, but not limited to, a driver circuit previously described in connection with
In certain embodiments, at least one panel or substrate portion can comprise a heat conduit panel portion 2430F for conductive thermal communication with the solid state emitters 2420 and optionally having mounting elements (e.g., holes or protrusions) arranged therein. Following various planar processing steps (e.g., deposition of insulating material, formation of electrical traces, mounting or addition of control circuit element(s) 2450, and optionally mounting solid state emitters 2420 (since such mounting may be performed after cutting and/or shaping steps), substrate 2410 may be cut, scribed, or otherwise processed or manipulated as necessary (e.g., to form and/or segregate the substrate and panel from adjacent portions of a carrier). Upon bending or other shaping of substrate 2410, the substrate panel portions 2430A-2430F may be arranged in a multi-planar conformation to yield a substantially rigid upright support structure or apparatus with multiple non-coplanar substrate portions arranged as illustrated in
In certain embodiments, multiple sets of solid state light emitters 2420 configured to be activated and/or deactivated at different times relative to one another during a portion of an AC cycle as previously described (see e.g.,
Light bulb 2500 includes a globe, diffuser, and/or other optical element 2510 (e.g., arranged to transmit, mix, and/or diffuse emissions of LEDs of multiple emitter sets S1 to S3) disposed over a base portion 2520. Each LED 2420 may be arranged over an emitter mounting area 2450. In certain embodiments, the globe 2510 may serve as a lumiphor support element that is spatially segregated from the multiple emitter sets S1 to S3 and that supports (e.g., is coated with) at least one lumiphoric material arranged to be stimulated by emissions of at least some solid state light emitters of the multiple emitter sets S1 to S3. Globe portion 2510 may promote color mixing of light emitted by multiple LEDs 2420. Apparatus 2400 can be arranged below globe portion 2510 to enable multi-directional transmission of light through globe portion 2510. In certain embodiments, globe portion 2510 can be faceted and/or textured to produce a desired pattern or directional output of light.
As shown in
In certain embodiments, multiple LEDs 2830 can be provided in multiple rows or multiple arrays over each portion of substrate 2810. LEDs 2830 can be arranged in multiple mutually exclusive set S1, S2, and S3 having varying duty cycles. LEDs 2830 of different duty cycles and, therefore, LEDs of different sets S1, S2, and S3 can be provided over each portion of substrate 2810. LEDs 2830 of different sets S1, S2, and S3 can be intermixed over portions of substrate 2810 for improving light emission and for reducing perceptible flicker and/or color variation during turning on and/or off various sets S1, S2, and S3.
As illustrated in
In certain embodiments, apparatus 2800 can comprise a support element 2840 extending below centralized portion 2820 and/or below peripheral portions of substrate 2810, with the support element 2840 optionally being arranged to contain or support at least one driver circuit element (not shown). The support element 2840 or circuit element(s) therein can receive electrical signal or power directly from an AC power source via pins or connectors proximate to the support element 2840.
As
In certain embodiments, apparatus 3300 can comprise at least one remotely located driver circuit element. That is, one or more circuit elements adapted to control apparatus 3300 and/or sets of LEDs 3320 disposed thereon can be disposed at a remote location and away from the substrate 3310 and LEDs 3320 arranged thereon.
Embodiments as disclosed herein may provide one or more of the following beneficial technical effects: reduced cost of solid state lighting devices; reduced size or volume of solid state lighting devices; reduced perceptibility of flicker of solid state lighting devices operated with AC power; reduced perceptibility of variation in intensity (e.g., with respect to area and/or direction) of light output by solid state lighting devices operated with AC power; reduced perceptibility of variation (e.g., with respect to area and/or direction) in output color and/or output color temperature of light output by solid state lighting devices operated with AC power; improved dissipation of heat (and concomitant improvement of operating life) of solid state lighting devices operated with AC power; improved manufacturability of solid state lighting devices operated with AC power; improved ability to vary color temperature of emissions of solid state lighting devices operated with AC power; improved ability to vary beam size, beam pattern, and/or direction of light output by solid state lighting devices operated with AC power.
While the invention has been has been described herein in reference to specific aspects, features, and illustrative embodiments, it will be appreciated that the utility of the invention is not thus limited, but rather extends to and encompasses numerous other variations, modifications and alternative embodiments, as will suggest themselves to those of ordinary skill in the field of the present invention, based on the disclosure herein. Various combinations and sub-combinations of the structures and features described herein are contemplated and will be apparent to a skilled person having knowledge of this disclosure. Any of the various features and elements as disclosed herein may be combined with one or more other disclosed features and elements unless indicated to the contrary herein. Correspondingly, the invention as hereinafter claimed is intended to be broadly construed and interpreted, as including all such variations, modifications and alternative embodiments, within its scope and including equivalents of the claims.
Subject matter disclosed herein relates at least in part to U.S. patent application Ser. No. 13/192,755 [P1364] (published as U.S. Patent Application Publication No. 2013/0026925), U.S. patent application Ser. No. 13/339,974 [P1454], U.S. patent application Ser. No. 13/235,103 [P1459], U.S. patent application Ser. No. 13/235,127 [P1461], and U.S. patent application Ser. No. 13/360,145 [P1556]. The disclosures of the foregoing patent applications are hereby incorporated by reference as if set forth fully herein.
