Luminaire with encapsulated light-emitting diodes

Abstract

A luminaire (1000) includes a housing (1005) and a light-emitting diode ("LED") assembly (1040) connected to the housing (1005). The LED assembly includes a printed circuit board assembly (1060), a plurality of LEDs connected to the printed circuit board assembly (1060), and a reflector (1055) that includes a plurality of LED receptacles (1065). Each one of the plurality of LED receptacles (1065) receives a respective one of the plurality of LEDs. An encapsulant (1070) fills each one of the plurality of LED receptacles (1065) and covers the respective one of the plurality of LEDs.

Description

LUMINAIRE WITH ENCAPSULATED LIGHT-EMITTING DIODESCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of Indian Provisional Patent Application 202411008222, filed February 7, 2024, the disclosure of which is incorporated by reference herein in its entirety.FIELD OF INVENTION

[0002] The present disclosure is directed to luminaires. More particularly, the present disclosure is directed to a luminaire with encapsulated light-emitting diodes.BACKGROUND

[0003] Luminaires are used to provide illumination to an area. Certain applications require luminaires to operate within environments that are considered hazardous due to the presence of gas, vapor, dust, etc. A number of standards have been promulgated relating to the use of electrical products, including luminaires, in hazardous environments to improve safety in view of an assessed probability of explosion or fire risk.

[0004] For example, the International Electrotechnical Commission (IEC) categorizes hazardous environments into Zone 0, Zone 1, or Zone 2. In Zone 0 environments, ignitable concentrations of flammable gases or vapors are present continuously or for long periods of time. In Zone 1 environments, ignitable concentrations of flammable gases or vapors are likely to exist because of repair or maintenance operations or because of leakage or possible release of ignitable concentrations of flammable gases or vapors. In Zone 2 environments, ignitableconcentrations of flammable gases or vapors are not likely to exist under normal operating conditions. The National Electrical Code (NEC) has similar standards, albeit using different terminology.SUMMARY OF THE INVENTION

[0005] In one embodiment, a luminaire includes a housing and a light-emitting diode (“LED”) assembly connected to the housing. The LED assembly includes a printed circuit board assembly, a plurality of LEDs connected to the printed circuit board assembly, and a reflector that includes a plurality of LED receptacles. Each one of the plurality of LED receptacles receives a respective one of the plurality of LEDs. An encapsulant fills each one of the plurality of LED receptacles and covers the respective one of the plurality of LEDs.

[0006] In another embodiment, a method of manufacturing a luminaire includes the steps of providing a housing, a printed circuit board assembly, a plurality of light-emitting diodes (“LED”), and a reflector that includes a plurality of LED receptacles. The plurality of LEDs are connected to the printed circuited board assembly. The plurality of LEDs are located in a respective one of the plurality of LED receptacles. The plurality of LED receptacles are filled with an encapsulant to cover the plurality of LEDs. The printed circuit board assembly is connected to the housing.

[0007] In yet another embodiment, a light-emitting diode (“LED”) assembly for a luminaire includes a printed circuit board assembly and a reflector connected to the circuit board assembly. The reflector includes a plurality of LED receptacles. Each one of the plurality of LED receptacles is shaped as a truncated pyramid andhas an opening. A plurality of LEDs are connected to the printed circuit board assembly. Each one of the plurality of LEDs is received in the opening of a respective one of the plurality of LED receptacles. An encapsulant covers the plurality of LEDs.BRIEF DESCRIPTION OF DRAWINGS

[0008] In the accompanying drawings, structures are illustrated that, together with the detailed description provided below, describe exemplary embodiments of the claimed invention. Like elements are identified with the same reference numerals. It should be understood that elements shown as a single component may be replaced with multiple components, and elements shown as multiple components may be replaced with a single component. The drawings are not to scale and the proportion of certain elements may be exaggerated for the purpose of illustration.

[0009] Figure 1 is a perspective view of one embodiment of a luminaire;

[0010] Figure 2 is another perspective view of the luminaire of Figure 1,

[0011] Figure 3 is an exploded perspective view of the luminaire of Figure 1,

[0012] Figure 4 is a partial, exploded, perspective view of the luminaire ofFigure 1,

[0013] Figure 5 is a perspective view of part of the luminaire of Figure 1,

[0014] Figure 6 is a top view of the luminaire of Figure 1, and

[0015] Figure 7 is a partial, sectional view of the luminaire of Figure 1.DETAILED DESCRIPTION

[0016] One embodiment of a luminaire 1000 is shown in Figures 1-6. The luminaire 1000 includes a housing 1005. The housing 1005 is substantially cuboid shaped. Cooling fins 1007 extend from a rear wall 1010 of the housing 1005. In the illustrated embodiment, the housing 1005 includes eleven substantially linear cooling fins 1007 that each run along the entire height of the rear wall 1010. A substantially U-shaped yoke 1015 is connected to mounting ears 1020 on the housing 1005. The yoke 1015 may be used to mount the luminaire 1000 to a ceiling, wall, or any other desired surface or structure. An optional sensor receptacle 1025 extends from a side wall 1030 of the housing 1005. The sensor receptacle 1025 may receive a sensor (not shown) that, for example, activates the luminaire when motion is detected or activates the luminaire a dark environment is sensed. The sensor receptacle 1025 is provided with a plug 1035 that seals the sensor receptacle 1025 for applications that do not require a sensor. In alternative embodiments, the housing may be any desired shape. In other alternative embodiments, the housing may have any number of cooling fins in any desired configuration (e.g., extend horizontally rather than vertically, extend along only part of the height of the rear wall) or the cooling fins may be omitted. In still yet other alternative embodiments, the yoke and mounting ears may have any desired configuration or may be omitted. In still yet even other alternative embodiments, the cooling fins, the yoke, or the sensor receptacle may be provided at any desired location on the luminaire other than what is shown in the drawings.

[0017] A light-emitting diode (“LED”) assembly 1040 is mounted to the housing 1005. The LED assembly 1040 includes an LED assembly base 1043. The LED assembly base 1043 and the rear wall 1010 of the housing 1005 define an interior space 1045. A driver 1050 is located in the interior space 1045. As understood by those of ordinary skill in the art, the driver 1050 rectifies higher voltage, alternating current to low-voltage, direct current that is generally needed to operate LEDs. Furthermore, the driver 1050 protects LEDs from voltage or current fluctuations. Additional electrical components may also be located in the interior space 1045. In alternative embodiments, the driver may be located at any desired location in or on the luminaire. In other alternative embodiments, the driver may be omitted and the luminaire may use, for example, driverless LED bulbs, otherwise known as driver-on-board LED bulbs.

[0018] A gasket 1051 is provided between the LED assembly base 1043 and the housing 1005. The gasket 1051 creates a seal to prevent weather, dirt, or other contaminants from entering the interior space 1045. Cooling fins 1053 extend from a rear wall 1054 of the LED assembly base 1043. In the illustrated embodiment, the LED assembly base 1043 includes eleven substantially linear cooling fins 1053 that each run along the entire height of the rear wall 1054. In alternative embodiments, the gasket may have any desired configuration or may be omitted. For example, the assembly base or housing may be dimensioned and configured such that the tolerances between the two components prevent the entrance of weather, dirt, or other contaminants without the use of a gasket. In other alternative embodiments, the LED assembly base may have any number of cooling fins in anydesired configuration (e.g., extend horizontally rather than vertically, extend along only part of the height of the rear wall) or the cooling fins may be omitted.

[0019] The LED assembly 1040 includes a reflector 1055 that is connected to a printed circuit board assembly 1060. The printed circuit board assembly 1060 is connected to the LED assembly base 1043. In the illustrated embodiment, the reflector 1055 is mounted directly to the printed circuit board assembly 1060 and includes thirty-two separate LED receptacles 1065 that are arranged in a square grid. Each LED receptacle 1065 is shaped as a truncated pyramid (i.e., square frustum). The narrower portion of the truncated pyramid faces the printed circuit board assembly 1060 and includes an opening 1067. The opening 1067 receives a single LED 1075 that is connected to the printed circuit board assembly 1060. In alternative embodiments, the reflector may be indirectly mounted to the printed circuit board assembly. In other alternative embodiments, the reflector may include a fewer or greater number of LED receptacles or the LED receptacles may be arranged in any desired grid shape. In still yet other alternative embodiments, each LED receptacle may be any desired shape. In still yet even other alternative embodiments, each opening may receive more than one LED.

[0020] Each LED receptacle 1065 is filled with an encapsulant 1070 that covers the respective LED 1075. The encapsulant 1070 may be silicone, polyurethane, or any other appropriate material. The encapsulant 1070 is fully contained within each LED receptacle 1065. In other words, the encapsulant 1070 in one LED receptacle 1065 is discrete from, and does not contact, the encapsulant 1070 of any adjacent LED receptacle 1065. In one embodiment, the encapsulant 1070 has a thickness Tof approximately three millimeters. As used herein, “thickness” refers to the distance between the LED 1075 and the upper periphery of the encapsulant 1070. In alternative embodiments, the encapsulant may have a thickness of between 3-5 mm. In other alternative embodiments, the encapsulant may have any desired thickness. The encapsulant 1070 helps to isolate the LED 1075 from the ambient environment, thereby reducing the potential for ignition of flammable gases or vapors.

[0021] The luminaire 1000 includes a transparent or translucent cover plate 1080. The cover plate 1080 may be made of glass, diffused glass, polycarbonate, or any other desired material. The LED assembly base 1043 includes a lip 1085 that supports the cover plate 1080. A flange 1095 clamps the cover plate 1080 to the lip 1085. The flange 1095 and cover plate 1080 reduce the probability of weather, dirt, or other contaminants from contacting the LED assembly 1040. In alternative embodiments, the cover plate may be connected to the luminaire using any desired arrangement. For example, an adhesive may be used to connect the cover plate to the luminaire. In other alternative embodiments, the cover plate may be omitted.

[0022] The encapsulant 1070 allows the luminaire 1000 to safely operate in IEC Zone 1 environments. Compared to known luminaires that can operate in IEC Zone 1 environments, the luminaire 1000 described herein provides a more robust arrangement. In particular, the use of discrete encapsulants 1070 for each LED receptacle 1065 reduces the possibility of encapsulant delamination. Furthermore, the reflector 1055 reduces light loss associated with known luminaires.

[0023] To the extent that the term “includes” or “including” is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use. See Bryan A. Gamer, A Dictionary of Modem Legal Usage 624 (2d. Ed. 1995). Also, to the extent that the terms “in” or “into” are used in the specification or the claims, it is intended to additionally mean “on” or “onto.” Furthermore, to the extent the term “connect” is used in the specification or claims, it is intended to mean not only “directly connected to,” but also “indirectly connected to” such as connected through another component or components.

[0024] While the present disclosure has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the disclosure, in its broader aspects, is not limited to the specific details, the representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's general inventive concept. For example, the discrete encapsulants for each LED as described herein my be utilizedwith any desired luminaire, including luminaires that use light sources other than LEDs or luminaires having a configuration that is different from what is shown in the drawings.

Claims

CLAIMSWhat is claimed is:

1. A luminaire comprising: a housing; and a light-emitting diode (“LED”) assembly connected to the housing, the LED assembly comprising: a printed circuit board assembly; a plurality of LEDs connected to the printed circuit board assembly; a reflector that includes a plurality of LED receptacles, each one of the plurality of LED receptacles receiving a respective one of the plurality of LEDs; and an encapsulant that fills each one of the plurality of LED receptacles and covers the respective one of the plurality of LEDs.

2. The luminaire of claim 1, wherein the encapsulant of one of the plurality of LED receptacles is discrete from the encapsulant of any adjacent LED receptacles.

3. The luminaire of claim 1, wherein the encapsulant is silicone or polyurethane.

4. The luminaire of claim 1, wherein the encapsulant has a thickness of between 3-5 mm.

5. The luminaire of claim 1, wherein each one of the plurality of LED receptacles is shaped as a truncated pyramid.

6. The luminaire of claim 1, wherein the plurality of LED receptacles are arranged in a square grid.

7. The luminaire of claim 1, further comprising an LED assembly base, the printed circuit board assembly being connected to the LED assembly base, the LED assembly base including cooling fins.

8. The luminaire of claim 7 further comprising a cover plate connected to the LED assembly base.

9. The luminaire of claim 8 further comprising a flange, the flange clamping the cover plate to a lip on the LED assembly base.

10. The luminaire of claim 7 further comprising a gasket between the LED assembly base and the housing.

11. A method of manufacturing a luminaire comprising the steps of: providing a housing, a printed circuit board assembly, a plurality of light-emitting diodes (“LED”), and a reflector that includes a plurality of LED receptacles; connecting the plurality of LEDs to the printed circuited board assembly; locating the plurality of LEDs in a respective one of the plurality ofLED receptacles;filling the plurality of LED receptacles with an encapsulant to cover the plurality of LEDs; and connecting the printed circuit board assembly to the housing.

12. The method of manufacturing a luminaire of claim 11, wherein the encapsulant in one of the plurality of LED receptacles is discrete from the encapsulant of any adjacent LED receptacles.

13. The method of manufacturing a luminaire of claim 11, wherein the encapsulant is silicone or polyurethane.

14. The method of manufacturing a luminaire of claim 11, wherein the encapsulant has a thickness of between 3-5 mm.

15. The method of manufacturing a luminaire of claim 11 , wherein the plurality of LED receptacles are arranged in a square grid16. A light-emitting diode (“LED”) assembly for a luminaire, the LED assembly comprising: a printed circuit board assembly; a reflector connected to the circuit board assembly, the reflector including a plurality of LED receptacles, each one of the plurality of LED receptacles being shaped as a truncated pyramid and having an opening; a plurality of LEDs connected to the printed circuit board assembly, each one of the plurality of LEDs being received in the opening of a respective one of the plurality of LED receptacles; andan encapsulant that covers the plurality of LEDs.

17. The LED assembly of claim 16, wherein the encapsulant in one of the plurality of LED receptacles is discrete from the encapsulant of any adjacent LED receptacles18. The LED assembly of claim 17, wherein the encapsulant is silicone or polyurethane.

19. The LED assembly of claim 17, wherein the encapsulant has a thickness of between 3-5 mm.

20. The LED assembly of claim 17, wherein the plurality of LED receptacles are arranged in a square grid.

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