WO2017060210A1

WO2017060210A1 - Shock-preventing lighting units

Info

Publication number: WO2017060210A1
Application number: PCT/EP2016/073615
Authority: WO
Inventors: Brian David CLARKE
Original assignee: Philips Lighting Holding B.V.
Priority date: 2015-10-07
Filing date: 2016-10-04
Publication date: 2017-04-13

Abstract

In various embodiments, an LED-based lighting unit (100, 200, 300, 400) may include: a base (102, 202, 402) shaped for removable insertion into a socket of a luminaire. The base may define a base exterior and a base interior, and may include a conductive path (108, 408) passing from the base exterior into the base interior. One or more exposed electrical components (118-126, 226, 470, 474) and/or one or more light-emitting diodes (116, 416) may be in electrical communication with the conductive path. A frangible outer envelope (104, 204, 304, 404) may be directly or indirectly mounted on the base. An inner envelope (106, 206, 306, 406) may be directly or indirectly mounted on the base and may define an inner chamber (107, 207, 307, 407) that houses the one or more exposed electrical components. The frangible outer envelope may be spaced from the inner envelope to define an intermediate chamber (114, 214, 314, 414) therebetween. The inner envelope may shield the one or more exposed electrical components from human touch on rupture of the outer envelope.

Description

SHOCK-PREVENTING LIGHTING UNITS

Technical Field

[0001] The present invention is directed generally to lighting units. More particularly, various inventive apparatus disclosed herein relate to lighting units configured to shield exposed electrical components from human contact in the event of rupture.

Background

[0002] Digital lighting technologies, i.e., illumination based on semiconductor light sources, such as light-emitting diodes (LEDs), offer a viable alternative to traditional fluorescent, HID, and incandescent lamps. Functional advantages and benefits of LEDs include high energy conversion and optical efficiency, durability, lower operating costs, and many others. Recent advances in LED technology have provided efficient and robust full-spectrum lighting sources that enable a variety of lighting effects in many applications. Some of the fixtures embodying these sources feature a lighting module, including one or more LEDs capable of producing different colors, e.g., red, green, and blue, as well as a processor for independently controlling the output of the LEDs in order to generate a variety of colors and color-changing lighting effects, for example, as discussed in detail in U .S. Patent Nos. 6,016,038 and 6,211,626, incorporated herein by reference.

[0003] Various safety regulations require that some products be provided with some sort of protective enclosure to prevent human contact with electrically live components that present a risk of shock. For example, U nderwriter's Laboratories, Inc. ("U L") standard 1993, which is used as the ANSI Standard for Safety for Self-Ballasted Lamps and Lamp Adapters, requires that a self-ballasted lamp or lighting unit, such as an LED lighting unit, must pass a so-called "drop im pact" test. This test requires that the lighting unit be dropped from a specific height onto a hardwood surface a number of times. The lighting unit passes the test if no live electrical components are exposed to potential human contact after the drops. [0004] LED lighting units are typically more expensive than other types of lighting units, such as incandescents, compact fluorescents, halogen, etc. Part of the reason is that LED lighting units are often constructed with non-frangible or break-resistant plastic coverings, or

"envelopes," in order to satisfy the various regulations described above. Plastic is relatively expensive, especially compared to the glass used to manufacture other, less expensive types of lighting units. Accordingly, there is a need to reduce costs associated with LED lighting units in order to make them more competitive with other types of lighting units while still satisfying various safety regulations.

Summary

[0005] The present disclosure is directed to inventive methods and apparatus for a lighting unit, often an LED lighting unit, that is designed to shield exposed (and potentially live) electrical components from human contact in the event of a rupture of an outermost envelope. For example, an LED lighting unit may be constructed with a frangible outer envelope and an inner envelope configured to shield one or more exposed electrical components from human contact on rupture of the outer envelope.

[0006] Generally, in one aspect, an LED-based lighting unit may include: a base shaped for removable insertion into a socket of a luminaire, the base defining a base exterior and a base interior; a conductive path passing from the base exterior into the base interior, the conductive path configured make contact with a conductive path of the luminaire socket when the base is inserted into the luminaire socket; one or more exposed electrical components in electrical communication with the conductive path; one or more light emitting diodes in electrical communication with the one or more exposed electrical components; a frangible outer envelope coupled to the base and having an exterior surface and an interior surface; and an inner envelope coupled to the base and defining an inner chamber that houses the one or more exposed electrical components, wherein at least a portion of the interior surface of the frangible outer envelope is spaced from the inner envelope to define an intermediate chamber between the interior surface of the outer envelope and the inner envelop, wherein the inner envelope shields the one or more exposed electrical components from human touch on rupture of the outer envelope.

[0007] In various embodiments, the frangible outer envelope is directly or indirectly mounted to the base and the inner envelope is directly or indirectly mounted to the base.

[0008] In various embodiments, the inner envelope defines at least one passage to provide gaseous communication between the inner chamber and the intermediate chamber. In various versions, the intermediate chamber is filled with a gas. In various versions, the at least one passage is located on an end of the inner envelope that is distal from the base. In various embodiments, the at least one passage is a slot that extends along a side of the inner envelope. In various versions, the slot extends parallel to an axis between a first end of the inner envelope that is adjacent the base and a second, opposite end of the inner envelope. In various versions, the at least one passage includes a plurality of perforations in the inner envelope.

[0009] In various embodiments, the inner envelope may be comprised at least partially of a polymeric material. In various embodiments, the inner envelope may be comprised at least partially of glass. In various embodiments, the inner and outer envelopes form a single, integral unit that is mounted to the base. In various embodiments, the inner envelope may include a metallic reinforcing structure. In various versions, the metallic reinforcing structure may include a plurality of metal rods spaced apart to define one or more gaps through which light passes from the one or more LED-based light sources.

[0010] In various embodiments, the outer envelope may be comprised of glass. In various versions, the metallic reinforcing structure may be spaced from the one or more exposed electrical components. In various embodiments, the one or more exposed electrical components may include one or more of an LED, a ballast, an LED controller, and an AC-to-DC converter.

[0011] As used herein for purposes of the present disclosure, the term "LED" should be understood to include any electroluminescent diode or other type of carrier injection/junction- based system that is capable of generating radiation in response to an electric signal. Thus, the term LED includes, but is not limited to, various semiconductor-based structures that emit light in response to current, light emitting polymers, organic light emitting diodes (OLEDs), electroluminescent strips, and the like. In particular, the term LED refers to light emitting diodes of all types (including semi-conductor and organic light emitting diodes) that may be configured to generate radiation in one or more of the infrared spectrum, ultraviolet spectrum, and various portions of the visible spectrum (generally including radiation wavelengths from approximately 400 nanometers to approximately 700 nanometers). Some examples of LEDs include, but are not limited to, various types of infrared LEDs, ultraviolet LEDs, red LEDs, blue LEDs, green LEDs, yellow LEDs, amber LEDs, orange LEDs, and white LEDs (discussed further below). It also should be appreciated that LEDs may be configured and/or controlled to generate radiation having various bandwidths (e.g., full widths at half maximum, or FWHM) for a given spectrum (e.g., narrow bandwidth, broad bandwidth), and a variety of dominant wavelengths within a given general color categorization.

[0012] For example, one implementation of an LED configured to generate essentially white light (e.g., a white LED) may include a number of dies which respectively emit different spectra of electroluminescence that, in combination, mix to form essentially white light. In another implementation, a white light LED may be associated with a phosphor material that converts electroluminescence having a first spectrum to a different second spectrum. In one example of this implementation, electroluminescence having a relatively short wavelength and narrow bandwidth spectrum "pumps" the phosphor material, which in turn radiates longer wavelength radiation having a somewhat broader spectrum.

[0013] It should also be understood that the term LED does not limit the physical and/or electrical package type of an LED. For example, as discussed above, an LED may refer to a single light emitting device having multiple dies that are configured to respectively emit different spectra of radiation (e.g., that may or may not be individually controllable). Also, an LED may be associated with a phosphor that is considered as an integral part of the LED (e.g., some types of white LEDs). In general, the term LED may refer to packaged LEDs, non-packaged LEDs, surface mount LEDs, chip-on-board LEDs, T-package mount LEDs, radial package LEDs, power package LEDs, LEDs including some type of encasement and/or optical element (e.g., a diffusing lens), etc. [0014] The term "light source" should be understood to refer to any one or more of a variety of radiation sources, including, but not limited to, LED-based sources (including one or more LEDs as defined above), incandescent sources (e.g., filament lamps, halogen lamps), fluorescent sources, phosphorescent sources, high-intensity discharge sources (e.g., sodium vapor, mercury vapor, and metal halide lamps), lasers, other types of electroluminescent sources, pyro-luminescent sources (e.g., flames), candle-luminescent sources (e.g., gas mantles, carbon arc radiation sources), photo-luminescent sources (e.g., gaseous discharge sources), cathode luminescent sources using electronic satiation, galvano-luminescent sources, crystallo- luminescent sources, kine-luminescent sources, thermo-luminescent sources, triboluminescent sources, sonoluminescent sources, radioluminescent sources, and luminescent polymers.

[0015] A given light source may be configured to generate electromagnetic radiation within the visible spectrum, outside the visible spectrum, or a combination of both. Hence, the terms "light" and "radiation" are used interchangeably herein. Additionally, a light source may include as an integral component one or more filters (e.g., color filters), lenses, or other optical components. Also, it should be understood that light sources may be configured for a variety of applications, including, but not limited to, indication, display, and/or illumination. An

"illumination source" is a light source that is particularly configured to generate radiation having a sufficient intensity to effectively illuminate an interior or exterior space. In this context, "sufficient intensity" refers to sufficient radiant power in the visible spectrum generated in the space or environment (the unit "lumens" often is employed to represent the total light output from a light source in all directions, in terms of radiant power or "luminous flux") to provide ambient illumination (i.e., light that may be perceived indirectly and that may be, for example, reflected off of one or more of a variety of intervening surfaces before being perceived in whole or in part).

[0016] The terms "lighting fixture" and "luminaire" are used herein to refer to an

implementation or arrangement of one or more lighting units in a particular form factor, assembly, or package. The term "lighting unit" is used herein to refer to an apparatus including one or more light sources of same or different types. A given lighting unit may have any one of a variety of mounting arrangements for the light source(s), enclosure/housing arrangements and shapes, and/or electrical and mechanical connection configurations. Additionally, a given lighting unit optionally may be associated with (e.g., include, be coupled to and/or packaged together with) various other components (e.g., control circuitry) relating to the operation of the light source(s). An "LED-based lighting unit" refers to a lighting unit that includes one or more LED-based light sources as discussed above, alone or in combination with other non LED-based light sources. A "multi-channel" lighting unit refers to an LED-based or non LED-based lighting unit that includes at least two light sources configured to respectively generate different spectrums of radiation, wherein each different source spectrum may be referred to as a "channel" of the multi-channel lighting unit.

[0017] The term "controller" is used herein generally to describe various apparatus relating to the operation of one or more light sources. A controller can be implemented in numerous ways (e.g., such as with dedicated hardware) to perform various functions discussed herein. A "processor" is one example of a controller which employs one or more microprocessors that may be programmed using software (e.g., microcode) to perform various functions discussed herein. A controller may be implemented with or without employing a processor, and also may be implemented as a combination of dedicated hardware to perform some functions and a processor (e.g., one or more programmed microprocessors and associated circuitry) to perform other functions. Examples of controller components that may be employed in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs).

[0018] In various implementations, a processor or controller may be associated with one or more storage media (generically referred to herein as "memory," e.g., volatile and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM, floppy disks, compact disks, optical disks, magnetic tape, etc.). In some implementations, the storage media may be encoded with one or more programs that, when executed on one or more processors and/or controllers, perform at least some of the functions discussed herein. Various storage media may be fixed within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor or controller so as to implement various aspects of the present invention discussed herein. The terms "program" or "computer program" are used herein in a generic sense to refer to any type of computer code (e.g., software or microcode) that can be employed to program one or more processors or controllers.

[0019] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.

Brief Description of the Drawings

[0020] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.

[0021] Fig.1 schematically illustrates an example LED lighting unit configured with selected aspects of the present disclosure, in accordance with various embodiments.

[0022] Figs.2A-E depict various embodiments of LED lighting units configured with selected aspects of the present disclosure.

[0023] Fig.3 depicts an example integral outer and inner envelop for a lighting unit, in accordance with various embodiments.

[0024] Fig.4 depicts an example lighting unit configured with selected aspects of the present disclosure, in accordance with various embodiments. Detailed Description

[0025] Various regulations require that products with electrically live components that present a risk of shock be provided with some sort of protective enclosure to prevent human contact with those electrical components. To satisfy such regulations, LED lighting units may be manufactured with materials that are more expensive than materials used to manufacture other types of lighting units, such as incandescents, compact fluorescents, halogen, etc.. For example, there is a push within the LED lamp design community to use glass as much as possible for the entire LED lamp structure/enclosure because of its inexpensive nature and the existing glass lamp manufacturing infrastructure. This can present a problem with regulation and preventing human contact, because glass lamps constructed similar to existing general purpose incandescent lamps typically fail regulation tests by breaking and exposing electrically live parts that are a risk of electric shock.

[0026] Accordingly, there is a need to reduce costs associated with LED lighting units in order to make them more competitive with other types of lighting units, while still satisfying various safety regulations. In view of the foregoing, various embodiments and

implementations of the present invention are directed to LED lighting units that include an outer envelope (which may constructed with material generally considered to be frangible) and an inner envelope designed to shield one or more exposed and potentially live electrical components from human contact in the event of rupture of the outer envelope. The outer envelope is sacrificial and breaks if subjected to impact. The inner envelope is contracted such that it remains intact if subjected to impact in order to prevent contact with the electrically live parts.

[0027] Fig. 1 schematically depicts an LED lighting unit 100 according to one embodiment. LED lighting unit 100 may include a base 102, an outer envelope 104 directly or indirectly mounted to base 102, and an inner envelope 106 directly or indirectly mounted to base 102. In various embodiments, inner envelope 106 may define an inner chamber 107. In various embodiments, base 102 may be shaped for removable insertion into a socket (not depicted) of a luminaire (also not depicted). For example, in Fig.1, base 102 includes threads that enable LED lighting unit 100 to be screwed into a similarly-threaded luminaire socket. In other embodiments, base 102 may be secured within a luminaire socket using other mechanisms, such as snaps, locks, and so forth. In various embodiments, a conductive path 108 may pass from an exterior of base 102 into an interior of base 102. Conductive path 108 may be configured make contact with a corresponding conductive path (not depicted) of a luminaire socket when base 102 is inserted into the luminaire socket.

[0028] In various embodiments, outer envelope 104 may be constructed with various materials. Some of these materials may be frangible. For example, in some embodiments, outer envelope 104 is constructed with glass, which is typically less expensive than materials (e.g., plastic) traditionally used to construct LED lighting unit housings. In other embodiments, outer envelope 104 may be constructed with other materials, such as ceramics. In some embodiments, outer envelope 104 may be constructed with electrically insulate materials, although this is not required. Outer envelope may include an exterior surface 110 and an interior surface 112. In various embodiments, at least a portion of interior surface 112 of outer envelope 104 may be spaced from inner envelope 106 to define an intermediate chamber 114 between interior surface 112 of outer envelope 104 and inner envelope 106.

[0029] In various embodiments, in the event LED lighting unit 100 is dropped, outer envelope 104 may absorb the kinetic energy and may rupture as a result. To prevent human contact with various electrical components that may present a shock risk if live, various electrical components may be housed within inner chamber 107 of inner envelope 106. In this sense, outer envelope 104 may be "sacrificial," and inner envelop 106 may remain intact in the event of a drop to shield electrical components from human contact.

[0030] In some embodiments, inner envelope 106 may be mounted directly or indirectly to base 102. In other embodiments, inner envelope 106 may be directly or indirectly mounted on other components typically found in light bulbs, such as contact wires, button rods, stem presses, heat deflectors, exhaust tubes, and so forth. In some embodiments, such as that shown in Fig.2A, inner envelop 106 may be mounted on one or more pins. As noted above, inner envelope 106 may shield one or more exposed electrical components it encloses from human touch in the event of rupture of outer envelope 104. Inner envelope may take various forms, including those depicted in Fig.1 and Figs.2A-E. For example, the inner envelop 106 shown to be a rectangular shape, completely enclosing electrical components. Inner envelope 106 may be constructed from various materials. In some embodiments, inner envelope 106 may be constructed with insulate materials, such as ceramics, polymeric material, and/or glass. In some embodiments, inner envelope 106 may be constructed with break-resistant materials such as plastic or metal. Various examples of how inner envelope 106 may be constructed are described below.

[0031] In Fig.1, inner envelope 106 encloses one or more LEDs 116, a ballast 118, an LED driver 120, an AC-to-DC power converter 122, and a heat sink 124, all of which are mounted on a printed circuit board ("PCB") 126. In other embodiments, some of these components, such as heat sink 124, may not be mounted on PCB 126. Some LEDs 116 may be covered in materials such as silicone phosphor, and hence may not necessarily present a shock risk (although such materials are not designed to prevent shock, and may not be considered sufficient by safety regulators). However, the other components 118-126 may include various exposed electrical features (e.g., PCB 126 may include any number of exposed surface mount contacts, solder pads, or leads) that could shock someone who touches them. Accordingly, PCB 126 and other electrical components are enclosed within inner chamber 107 of inner envelope 106, shielded from human contact in the event outer envelope 104 ruptures.

[0032] This example is not meant to be limiting. In other embodiments, other electrical components that may present a shock risk may also be enclosed within inner envelop 106, including but not limited to an electrically live heat sink, spring connectors, and so forth. Also, Fig.1 is schematic, which means the components are not necessarily going to be physically arranged as shown. For example, in some embodiments, PCB 126 may be mounted within base 102 (as is the case in the embodiment of Fig.4).

[0033] The interior of some lighting units may be filled with various gases (e.g., helium) to aid in heat dissipation through processes such as convection and/or conduction. However, if inner chamber 107 is sealed from intermediate chamber 114, the benefits of including gases within LED lighting unit 100 would be diminished. Accordingly, in various embodiments, one or more passages may be defined between inner envelope 106 and intermediate chamber 114 to provide gaseous communication therebetween. Examples of such passages are depicted in Figs. 2A-E, in which gas is permitted to pass between an intermediate chamber 214 and an inner chamber 207 of inner envelope 206 through various types of passages. I n Figs. 2A-E, LED lighting unit 200 includes many components similar to those depicted in Fig. 1, and so those components are labeled similarly. For example, in Fig. 1, the outer envelope was labeled with 104; in Figs. 2A-E, the outer envelope is labeled with 204. And so on.

[0034] In Fig. 2A, inner envelope 206 is supported by pins 230a and 230b that pass through inner envelope 206. Pins 230a and 230b may be connected to various components, such as PCB 226, which in turn may be supported on base 202 by other structure 260. Other structure 260 may include a variety of components, including but not limited to a button rod, stem press, or lead wires. Air may be permitted to pass between intermediate chamber 214 and the inner chamber of inner envelope 206 through a space 262 between a bottom of inner envelope 206 and outer envelope 204. Inner envelop 206 have comprise a tube construction having a cylindrical sides and a rounded end located distal from the bases 202.

[0035] In Figs. 2B-E, electrical components housed within inner envelope 206 (e.g., 116-126 in Fig. 1, 226 in Fig. 2A) are not depicted to better visualize features of inner envelope 206. In Fig. 2B, inner envelope 206 is a tube construction having a rounded end located distal from the base 202. The inner envelope 206 defines one or more slots 232 that extend along sides of inner envelope 206, of which two (232a and 232b) are visible in Fig. 2B. In some embodiments, the slots 232 may extend parallel to an axis between a first end of inner envelope 206 that is adjacent base 202 and a second, opposite end of inner envelope 206 that is distal from base 202, although this is not required. These slots 232a and 232b may operate as passages through which gas may pass between intermediate chamber 214 and the inner chamber 207 of inner envelope 206. These slots may be dimensioned so that gas may pass through but human appendages (e.g., a small child's fingers) will not fit.

[0036] In Fig. 2C, inner envelope 206 similarly comprises a tube construction having a rounded end located distal from the base 202. A series of perforations 234a-234d are defined through inner envelope 206. These perforations may be sized to permit passage of gas but to prevent passage of a human appendage. While four perforations are depicted, there may be more or less perforations in inner envelope 206 to permit passage of gas. Additionally, the perforations 234 may be uniformly sized and/or shaped, or non-uniformly sized and/or shaped. Perforations 234 may be placed uniformly on the inner envelope 206. Alternatively, they may be concentrated in one particular area or non-uniformly located.

[0037] In some embodiments, the inner envelope 206 comprises other shapes. In Fig. 2D for instance, inner envelope 206 comprises a rectangular shape. In some embodiments, at least one passage is located on or near an end of inner envelope 206 that is distal from base 202. In Fig. 2D, for instance, inner envelope 206 includes a series of vents depicted at 236a-d to permit passage of gas. In one embodiment depicted, two of these vents, 236a and 236b, are located at an end of inner envelope 206 that is distal from base 202. Two of these vents 236c and 236d, are located proximate to the base 202. In other embodiments, vents 236a-d may be located in other locations of the inner envelope 206 such as in the middle of the inner envelope 206. As with passages of other embodiments, vents 236a-d are sized so that gas may pass through, but human appendages may not.

[0038] In Fig. 2E, inner envelope 206 comprises a reinforcing structure 238 that acts as a "cage" to prevent contact with electrical components in the event of rupture of outer envelope 204. Reinforcing structure 238 may be constructed of various materials, such as plastic, ceramic, or metal. In some embodiments, reinforcing structure 238 may include a plurality of rods spaced apart from each other to define one or more gaps that are sized so that gas can pass through but human appendages cannot. In embodiments where reinforcing structure 238 is metallic, it may be spaced from any electrical components contained within inner envelope 206 in order to avoid contact. Reinforcing structure 238 may surround the electrical components forming a circular perimeter. Alternatively, reinforcing structure 238 may form other shapes forming perimeters and individual rods may be placed in different proximity to the electrical components.

[0039] Different mechanisms are depicted in each of Figs. 2A-E to demonstrate how passages between an inner chamber of inner envelope 206 and intermediate chamber 214 may be defined. However, this is not meant to be limiting. In some embodiments, more than one of the depicted mechanisms may be included in a single LED lighting unit. For example, both slots 232 of Fig. 2B and perforations 234 of Fig. 2C may be included in a single lighting unit.

Additionally, while inner envelope 206 in Figs. 2A-C and 2E have distal ends (i.e., distal from base 202) that are rounded, this is not meant to be limiting, and other shapes, such as the relatively flat distal ends of Figs. 1 and 2D, may be used instead.

[0040] In some embodiments, the inner and outer envelopes of a lighting unit may form a single, integral unit. An example of such an embodiment is depicted in Fig. 3, in which LED lighting unit 300 includes inner envelope 306 and outer envelope 304 that are integral. While not depicted in Fig. 3, inner envelope 306 may include one or more of the structures depicted in Figs. 2A-E in order to permit gas to pass between inner chamber 307 and intermediate chamber 314. In some embodiments, inner envelope 306 may be closed off with some sort of blocking member 340. In other embodiments, inner envelope 306 may be closed off by virtue of being inserted into a base (not shown in Fig. 3).

[0041] Fig. 4 depicts another embodiment of an LED-based lighting unit 400 configured with selected aspects of the present disclosure. Lighting unit 400 is similar to lighting unit 100 in many respects, and so various components are labeled similarly. I n this example, one or more LEDs are included in an LED assembly 416. LED assembly 416 is mounted via structure 460 that includes one or more lead wires 470 that pass through a stem press 472. I n this example, the LED packages themselves are not live (and thus do not pose a shock risk) because their solder pads (not visible in Fig. 4) are underneath the packages. However, pairs of rectangular jumpers 474 may be live. Accordingly, LED assembly 416 (including pairs of rectangular jumpers 474), lead wires 470, and a PCB that is within base 402 and thus not visible, are all contained in inner chamber 407 and thus shielded by inner envelope 406. In the event outer envelope 404 is ruptured, e.g., as a result of a drop or collision, inner envelope 406 will continue to shield live electrical components such as lead wires 470 and rectangular jumpers 474 from exposure.

[0042] While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

[0043] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

[0044] The indefinite articles "a" and "an," as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean "at least one."

[0045] The phrase "and/or," as used herein in the specification and in the claims, should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with "and/or" should be construed in the same fashion, i.e., "one or more" of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the "and/or" clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to "A and/or B", when used in conjunction with open-ended language such as "comprising" can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0046] As used herein in the specification and in the claims, "or" should be understood to have the same meaning as "and/or" as defined above. For example, when separating items in a list, "or" or "and/or" shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as "only one of" or "exactly one of," or, when used in the claims, "consisting of," will refer to the inclusion of exactly one element of a number or list of elements. In general, the term "or" as used herein shall only be interpreted as indicating exclusive alternatives (i.e. "one or the other but not both") when preceded by terms of exclusivity, such as "either," "one of," "only one of," or "exactly one of." "Consisting essentially of," when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0047] As used herein in the specification and in the claims, the phrase "at least one," in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B," or, equivalently "at least one of A and/or B") can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc. [0048] It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

[0049] In the claims, as well as in the specification above, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," "composed of," and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03. It should be understood that certain expressions and reference signs used in the claims pursuant to Rule 6.2(b) of the Patent Cooperation Treaty ("PCT") do not limit the scope

Claims

CLAIMS:

1. An LED-based lighting unit (100, 200, 300, 400) comprising:

a base (102, 202, 402) shaped for removable insertion into a socket of a luminaire, the base defining a base exterior and a base interior;

a conductive path (108, 408) passing from the base exterior into the base interior, the conductive path configured make contact with a conductive path of the luminaire socket when the base is inserted into the luminaire socket;

one or more exposed electrical components (116-126, 226, 416, 470, 474) in electrical communication with the conductive path;

one or more light emitting diodes (116, 216, 416) in electrical communication with the one or more exposed electrical components;

a frangible outer envelope (104, 204, 304, 404) coupled to the base and having an exterior surface (110, 410) and an interior surface (112, 412); and

an inner envelope (106, 206, 306, 406) coupled to the base and defining an inner chamber (107, 207, 307, 407) that houses the one or more exposed electrical components, wherein at least a portion of the interior surface of the frangible outer envelope is spaced from the inner envelope to define an intermediate chamber (114, 214, 314, 414) between the interior surface of the outer envelope and the inner envelop, wherein the inner envelope shields the one or more exposed electrical components from human touch on rupture of the outer envelope.

2. The LED-based lighting unit of claim 1, wherein the inner envelope defines at least one passage (232, 234, 236, 260) to provide gaseous communication between the inner chamber and the intermediate chamber.

3. The LED-based lighting unit of claim 2, wherein the intermediate chamber is filled with a gas.

4. The LED-based lighting unit of claim 2, wherein the at least one passage is located on an end of the inner envelope that is distal from the base.

5. The LED-based lighting unit of claim 2, wherein the at least one passage comprises a slot (232) that extends along a side of the inner envelope.

6. The LED-based lighting unit of claim 5, wherein the slot extends parallel to an axis between a first end of the inner envelope that is adjacent the base and a second, opposite end of the inner envelope.

7. The LED-based lighting unit of claim 2, wherein the at least one passage comprises a plurality of perforations (234) in the inner envelope.

8. The LED-based lighting unit of claim 1, wherein the inner envelope is comprised at least partially of a polymeric material.

9. The LED-based lighting unit of claim 1, wherein the inner envelope is comprised at least partially of glass.

10. The LED-based lighting unit of claim 1, wherein the inner and outer envelopes form a single, integral unit that is mounted to the base.

11. The LED-based lighting unit of claim 1, wherein the inner envelope comprises a metallic reinforcing structure (238).

12. The LED-based lighting unit of claim 11, wherein the metallic reinforcing structure comprises a plurality of metal rods spaced apart to define one or more gaps through which light passes from the one or more LED-based light sources.

13. The LED-based lighting unit of claim 11, wherein the metallic reinforcing structure is spaced from the one or more exposed electrical components.

14. The LED-based lighting unit of claim 1, wherein the outer envelope is comprised of glass.

15. The LED-based lighting unit of claim 1, wherein the one or more exposed electrical components include one or more of an LED (116, 416), a ballast (118), an LED driver (120), and an AC-to-DC converter (122).