Edge-lit luminaire with capability for secondary services - Patent Application 20070122967

Abstract

A lighting fixture is disclosed that includes a light-emitting diode (LED) engine including a plurality of LEDs that emit visible light, and a waveguide, where the plurality of LEDs surround the waveguide and emit visible light in the direction of the waveguide. The lighting fixture also includes a secondary element that provides secondary services. The lighting fixture also includes a housing defining a cavity, where the LED engine and waveguide are positioned within the cavity near the front of the lighting fixture and the secondary element is positioned within the cavity toward the rear of the lighting fixture. [Selected Figure] Figure 2

Description

Technical Field

[0001] The present disclosure generally relates to lighting fixtures, and more particularly to lighting fixtures that include a light-emitting element and at least one other element that provides a secondary service, with both elements being housed within the housing of the lighting fixture.

Background Art

[0002] Light-emitting diodes (LEDs) based on lighting systems can offer several energy and reliability advantages over other types of lighting systems, such as incandescent or fluorescent lighting. Thus, LEDs based on lighting systems are increasingly being used to replace other existing lighting technologies. Furthermore, it should be understood that LEDs based on lighting systems are also being used as other components, such as in home automation systems.

[0003] Automation systems are used to control various systems typically found in homes and office buildings, such as lighting, heating, security systems, and household appliances. Some examples of devices that can be controlled by an automation system include washing machines, dryers, ovens, and refrigerators. In fact, often, lighting fixtures include a light-emitting element, such as an LED light engine, and another element that provides a different function. For example, a lighting fixture may include a speaker that generates sound, or a microphone that detects the user's voice or other sounds.

[0004] Often, difficulties are encountered when trying to provide different functions within a single lighting fixture. This is because lighting fixtures typically have standard dimensions, and thus the amount of space available for accommodating various components is limited. Furthermore, often, additional components can prevent the ability to radiate light in a manner that is not only effective but also aesthetically appealing. Also, providing other functions within a lighting fixture poses challenges. For example, the sound quality or level of a speaker can be degraded in order to meet the lumen requirements of the lighting fixture. [Brief explanation of the drawing]

[0005] [Figure 1] This is a cross-sectional perspective view of the disclosed lighting fixture. [Figure 2] Figure 1 is an exploded view of the lighting fixture shown. [Figure 3] Figure 1 is a magnified view of a portion of the lighting fixture shown. [Figure 4] Another perspective view of the disclosed lighting fixture. [Modes for carrying out the invention]

[0006] The following detailed description illustrates the general principles of the present invention, and examples of the present invention are further shown in the accompanying drawings. In the drawings, the same reference numerals indicate identical or functionally similar elements.

[0007] Figure 1 is a cross-sectional perspective view of an exemplary luminaire 10. The luminaire 10 includes a bezel 20, a waveguide 22, a secondary element 26, a secondary element holder 28, a light-emitting diode (LED) engine 30, a first driver board 32, a driver board holder 34, a second driver board holder 36, a housing 40, an end cap or cover 42, and one or more mounting features such as a mounting spring. Although the luminaire 10 shown in Figure 1 represents a downlight, the embodiment in Figure 1 is by its nature illustrative. For example, in other embodiments, the luminaire 10 may be a parabolic aluminum reflector (PAR) type luminaire or a bulge reflector (BR) type luminaire.

[0008] In addition to generating light, the luminaire 10 also includes a secondary element 26, which is used to provide another secondary service in addition to generating light. In the non-limiting embodiments described, the secondary element 26 is a speaker for generating sound. In other embodiments, for example, the secondary element 26 may be a microphone or a motion detector.

[0009] The housing 40 constitutes a cavity 50 shaped to house a secondary element 26, a secondary element holder 28, an LED engine 30, a first driver board 32, a driver board holder 34, and a second driver board holder 36. In an unrestrictive embodiment as shown in Figure 1, the housing 40 includes a heat sink 46 made of a thermally conductive metal. The heat sink 46 is aligned with the inner surface of the housing 40. In another embodiment, the housing 40 is made of a conductive material that allows radio frequency (RF) signals to pass through, such as a thermally conductive plastic. The housing 40 constitutes a first end portion 52 and a second end portion 54. The first end portion 52 of the housing 40 constitutes a first opening 56 of the housing 40, and the second end portion 54 of the housing 40 constitutes a second opening 58 of the housing 40. As can be seen in Figure 1, a portion 41 of the housing 40 preferably has a roughly truncated conical contour, and the first opening 56 of the housing 40 is larger in dimensions than the second opening 58.

[0010] In the non-restrictive embodiment shown, the first end portion 52 of the housing 40 is attached to the bezel 20, and the second end portion 54 of the housing 40 is attached to the cover 42. The bezel 20 is preferably attached to the first end portion 52 of the housing 40 by a snap-fit ​​engagement. However, it should be understood that the bezel 20 and the housing 40 are not limited to the snap-fit ​​engagement, and the bezel 20 may be attached to the housing 40 using other fastening techniques. Furthermore, in alternative embodiments, the bezel 20 and the housing 40 may be integrated with each other within a single component. The cover 42 can be used to close and seal the second opening 58 of the housing 40.

[0011] Figure 2 is an exploded view of the luminaire 10 shown in Figure 1. Now referring to both Figures 1 and 2, the cover 42 may include one or more positioning features 60 for engaging with and positioning the second driver board 36. The second driver board 36 may include the LED engine 30 and various power electronics 62 required for the electrical operation of the luminaire 10. The driver board holder 34 may include one or more legs 70 that project toward the second end portion 54 of the luminaire 10 and toward the cover 42 when assembled. The legs 70 of the driver board holder 34 may act as positioning pins or features used to engage with the driver board holder 34 and mount the driver board holder 34 in place within the cavity 50 of the housing 40.

[0012] The driver board holder 34 may also constitute a shelf 72, the shelf 72 having a recessed surface 74 (a corresponding position on the outside of the holder 34 shown in Figure 2) on which the first driver board 32 can be seated. The first driver board 32 may be a printed circuit board (PCB) and may include an antenna (not shown), such as a trace antenna. However, those skilled in the art will understand that this disclosure should not be limited to trace antennas and PCBs. In one embodiment, it may be configured to receive short-range RF signals, such as Bluetooth® signals conforming to the Institute of Electrical and Electronics Engineers (IEEE) standard 802.1.5.

[0013] Referring to Figure 1, the secondary element 26 includes a first end portion 76 and a second end portion 78. The first end portion 76 of the secondary element 26, shown as a speaker, is seated on the front surface 80 of the driver board holder 34. Now referring to both Figures 1 and 2, the secondary element holder 28 comprises a first end portion 82, a second end portion 84, and a cavity 86 extending axially along the central axis AA of the luminaire 10. The first end portion 82 of the secondary element holder 28 includes one or more retaining flanges 90. As can be seen in Figure 1, the flanges 90 of the secondary element holder 28 allow the holder 28 to engage with retaining features 92 located along the inner surface 48 of the housing 40.

[0014] The second end portion 84 of the holder 28 constitutes a flange 96 that extends inward with respect to the axis AA of the luminaire 10. As can be seen in Figure 1, the flange 96 constitutes an opening 100 that is smaller in dimension than the second end portion 78 of the secondary element 26. Thus, the rear surface 98 of the flange 96 of the secondary element holder 28 holds the secondary element 26 in place within the housing 40 of the luminaire 10. For example, in the embodiment shown, the luminaire 10 is a downlight. Therefore, when the downlight is installed in a building, the end cap 42 is positioned on the top or upper end of the luminaire 10. When the downlight is installed, the flange 96 of the secondary element holder 28 prevents the secondary element 26 from moving downward and coming into contact with the waveguide 22.

[0015] The illuminator 10 is an edge-illuminated illuminator. That is, the LED engine 30 surrounds the waveguide 22 in the plane of the waveguide, i.e., surrounds the side edges of the waveguide 22 with respect to the central axis AA of the illuminator. The waveguide 22 is made of a material that has the property of illuminating its entire surface 102 (Figures 1 and 4) using the light generated by the LED engine 30. The advantage of using an edge-illuminated device is cost reduction, because fewer LEDs are typically required to produce the same lumen output. Referring to Figures 1 and 3, the LED engine 30 includes a backing material 104 and a plurality of LEDs 106 mounted on the backing material 104. The backing material 104 is preferably a selectively flexible material. In particular, the backing material 104 is preferably formed as a strip, and the strip is preferably bent into an annular or ring shape, as can be seen in Figure 3. Thus, the LED light engine 30 is best when it extends completely around the circumference 100 of the waveguide 22. In other words, the multiple LEDs 106 surround the waveguide 22 and transmit visible light in the direction toward the waveguide 22.

[0016] Referring now to Figure 4, the waveguide 22 can also be called an optical guide. The waveguide 22 is used to collect light generated by multiple LEDs 106 and direct the light to the front surface 102 of the waveguide 22 to provide illumination. The waveguide 22 often includes multiple polarizing elements (not shown), which are also called microstructures or three-dimensional elements. In one embodiment, the polarizing elements are prism-shaped cavities formed in the longitudinal direction of the waveguide 22 and are used to illuminate the entire surface 102 of the waveguide 22. The polarizing elements are distributed along the front surface 102 of the waveguide 22.

[0017] The waveguide 22 often comprises a plurality of holes 112, which are distributed in a predetermined pattern along the front surface 102 of the waveguide 22. In embodiments such as those shown, the holes 102 allow sound generated by a secondary element 26 (Figures 1 and 2), shown as a speaker, to be transmitted to the environment. The holes 112 are often arranged in a star pattern, in which the holes 102 are arranged to radiate outward from a central point along the front surface 102 of the waveguide 22. However, it should be understood that the embodiment in Figure 4 is merely illustrative in nature, and the holes 112 can be arranged in various patterns and shapes.

[0018] It should be understood that the holes 112 are positioned to provide acceptable sound quality and aesthetic appeal, as well as to meet any light output or lumen requirements. In other words, the holes 112 are positioned to create a light pattern that is considered visually appealing to consumers.

[0019] Referring to the drawings as a whole, the disclosed lighting assembly provides consumers with at least one other, i.e., secondary, service. For example, in the embodiment shown, the secondary service is a speaker for emitting sound. The LED light engine is positioned around a waveguide and directs light toward the waveguide. Edge-illuminated luminaires require less package space than conventional board-type LED light engines, which are typically mounted around the central part of the luminaire. Thus, edge-illuminated LEDs allow for sufficient package space for elements related to the secondary service. In other words, the edge-illuminated LED shape increases the package space for housing the speaker. Furthermore, the sound quality and level of the speaker are not compromised to meet the lumen requirements of the luminaire.

[0020] Although the forms of apparatus and methods described herein constitute preferred embodiments of the present invention, it should be understood that the present invention is not limited to these forms of apparatus and methods and can be modified without departing from the scope of the invention. [Explanation of Symbols]

[0021] 10 Lighting fixtures 20 Bezel 22 Waveguide 26 Secondary elements 28 Secondary element holder 30 LED Engine 32 First Driver Board 34 Driver Board Holder 36. Second driver board holder 40 Housing 42 End caps or covers 46 Heatsink 50 Cavity 104 Backing material 106 LED

Claims

1. A lighting fixture comprising: an LED engine including a plurality of LEDs configured to emit visible light; a housing defining a cavity, the LED engine and the waveguide being positioned within a first end portion of the housing that includes a front portion of the lighting fixture; the LEDs of the LED engine are configured to circumferentially surround a side edge of the waveguide relative to a central axis of the lighting fixture and to emit visible light in a direction toward the waveguide; a secondary element configured to provide secondary services, the secondary element being disposed aft of the waveguide and positioned within the cavity between the first end portion of the housing and a second end portion of the housing that includes a rear of the luminaire; A lighting fixture, wherein the waveguide includes a plurality of holes penetrating a front surface of the waveguide, the plurality of holes allowing sound to be transmitted from the secondary element to an environment of the lighting fixture or to be received by the secondary element from the environment of the lighting fixture.

2. 10. The lighting fixture of claim 1, wherein the waveguide includes a plurality of polarizing elements including prismatic cavities formed along a length of the waveguide, the polarizing elements configured to illuminate an entire front surface of the waveguide in response to receiving visible light from the plurality of LEDs.

3. The luminaire of claim 1 , wherein the secondary element comprises a microphone or a speaker.

4. 2. The lighting fixture of claim 1, further comprising a driver board holder interposed between a first driver board and a second driver board, the driver board holder including a shelf portion defining a recessed surface on which the first driver board rests, the driver board holder including one or more legs protruding in a direction toward the second end portion of the housing, the one or more legs mounting the second driver board within the cavity.

5. The luminaire of claim 1 , wherein the luminaire is a downlight.

6. 10. The lighting fixture of claim 1, wherein the LEDs of the LED engine are mounted on a backing material, the backing material being shaped as an annular ring extending around a circumference of the waveguide.

7. 10. The lighting fixture of claim 1, wherein the first end portion of the housing includes a heat sink made of a thermally conductive metal conforming to an interior surface of the housing.

8. The luminaire includes first and second driver boards positioned with the cavity between the second end portion and the secondary element; a driver board holder interposed between the first and second driver boards and the secondary element, the secondary element resting against a front surface of the driver board holder; 10. The lighting fixture of claim 1, further comprising a secondary element holder interposed between said secondary element and said waveguide.

9. 9. The lighting fixture of claim 8, wherein the front surface of the driver board holder defines a ledge, the ledge defining a recessed surface upon which the first driver board rests.

10. 10. The lighting fixture of claim 9, wherein the first driver board includes an antenna configured to receive short-range radio frequency (RF) signals.

11. 10. The lighting fixture of claim 9, wherein the driver board holder includes one or more legs that protrude in a direction toward the second end of the housing, the one or more legs mounting the second driver board within the cavity.

12. 12. The lighting fixture of claim 11, further comprising an end cap attached to the second end portion of the housing, the end cap including a positioning feature that engages the second driver board.

13. 9. The lighting fixture of claim 8, wherein the secondary element holder includes a first end portion including one or more retention flanges that engage retention features located along an interior surface of the housing.

14. 14. The lighting fixture of claim 13, wherein the secondary element holder includes a second end portion positioned forward of the first end portion, the second end portion including an inwardly extending flange defining a smaller opening than the second end portion.

15. 15. The lighting fixture of claim 14, wherein the secondary element holder is seated between a front surface of the driver board holder and a rear surface of the inwardly extending flange.

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