LED lighting unit including elongated heat sink and elongated lens

• US 7,815,338 B2
• Filed: 03/02/2008
• Issued: 10/19/2010
• Est. Priority Date: 03/02/2008
• Status: Active Grant

• Current Assignee: Ilumisys Incorporated (Altair Engineering Incorporated)
• Original Assignee: Altair Engineering Incorporated
• Inventors: Simon, David L, Yuan, Huaiyao, Siemiet, Dennis
• Primary Examiner(s): Husar; Stephen F
• Assistant Examiner(s): CRANSON JR, JAMES W
• Application Number:
  US12/040,901
• Publication Number:
  US 20090219713A1
• Time in Patent Office: 961 Days
• Field of Search: 362/218, 362/294, 362/373, 362/249.02, 362/800
• US Class Current: 362/218
• CPC Class Codes: F21K 9/275 Details of bases or housings, i.e. the parts between the light-generating element and the end caps; Arrangement of components within bases or housings F21K9/278 takes precedence
• CPC Class Codes: F21K 9/66 Details of globes or covers forming part of the light source
• CPC Class Codes: F21S 4/28 rigid, e.g. LED bars
• CPC Class Codes: F21V 15/013 the housing being an extrusion
• CPC Class Codes: F21V 17/104 using feather joints, e.g. tongues and grooves, with or without friction
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/76 with essentially identical parallel planar fins or blades, e.g. with comb-like cross-section
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A LED lighting unit including an elongated heat sink having two spaced apart longitudinal grooves, the grooves facing tangentially or at an angle greater than an angle between a tangent of the lighting unit at the groove and a radius of the lighting unit at the groove. At least one LED is mounted to the heat sink between the grooves, and the at least one LED is enclosed by a lens having bulged longitudinal edges by sliding the bulged longitudinal edges into the grooves.

Claims

1. A LED lighting unit comprising:

an elongated heat sink having two spaced apart longitudinal grooves and forming a single cavity with a flat surface therebetween, wherein an angle between a facing direction of each groove and a radius extending from a center of the lighting unit to an opening of the groove is at least as large as the angle between a tangent of the lighting unit at the opening of the groove and the radius;

at least one LED mounted to the flat surface of the heat sink between the grooves and within the cavity; and

an elongated lens having bulged longitudinal edges, each edge slidably engaged with the groove on the heat sink such that the elongated lens encloses the at least one LED.

2. The LED lighting unit of claim 1, wherein the facing direction of the each groove is tangential relative to a perimeter of the lighting unit.

3. The LED lighting unit of claim 1, wherein the facing directions of the grooves oppose each other, and wherein the lens includes a bend toward an interior of the lighting unit near each bulged longitudinal edge.

4. The LED lighting unit of claim 3, wherein the grooves face ninety degrees to the exterior of the tangent, and the angle of the bend is ninety degrees.

5. The LED lighting unit of claim 1, wherein the lens has a constant cross-section along its longitudinal length.

6. The LED lighting unit of claim 5, wherein the lens has a substantially U-shaped cross-section along its longitudinal length.

7. The LED lighting unit of claim 5, wherein the bulges on the bulged longitudinal edges have a circular cross-section, and wherein the cross-section of the grooves includes a circular-shaped section.

8. The LED lighting unit of claim 1, wherein the at least one LED includes at least one of an LED emitting ultraviolet light and an LED emitting colored light.

9. The LED lighting unit of claim 1, further comprising:

a printed circuit board electrically connecting the LEDs and mounted on the flat surface of the heat sink between the grooves.

10. The LED lighting unit of claim 1, wherein the heat sink has a constant cross-section along its longitudinal length.

11. The LED lighting unit of claim 10, further comprising:

at least one additional groove in a surface of the heat sink between the flat surface and the grooves, each additional groove configured to accept a screw to secure an end cap to the heat sink.

12. The LED lighting unit of claim 11, wherein the at least one additional groove opens to the exterior of the heat sink and extends the length of the heat sink.

13. The LED lighting unit of claim 10, further comprising:

a printed circuit board electrically connecting the LEDs and mounted to the flat surface between the two grooves.

14. The LED lighting unit of claim 10, wherein the heat sink includes a plurality of heat dissipating structures.

15. The LED lighting unit of claim 14, wherein the heat dissipating structures include fins projecting from an opposing side of the flat surface of the heat sink in a direction opposite from the LEDs.

16. The LED lighting unit of claim 1, further comprising:

an elongated sheet of diffusing film inserted between the heat sink and the lens.

17. The LED lighting unit of claim 16, wherein longitudinal edges of the diffusing film are located between the lens and the heat sink adjacent to the bulged edges.

18. The LED lighting unit of claim 1, further comprising:

two bi-pin electrical connectors disposed at opposing ends of the lens and heat sink, and wherein the lens and heat sink are configured to be part of a bulb placed in a conventional fluorescent tube socket.

19. The LED lighting unit of claim 1, wherein the thickness of the bulges is the same as the thickness of the lens.

20. An LED light tube configured to replace a conventional fluorescent light tube in a conventional fluorescent light socket, the LED light tube comprising:

an elongated heat sink having a constant cross-section along its longitudinal length, the heat sink including two spaced apart, tangentially facing, longitudinal grooves, a flat strip between the grooves, and a plurality of fins projecting from the flat strip on the opposite side as the grooves, the grooves each having a cross-section including a circular portion;

a plurality of LEDs in electrical communication with a printed circuit board, the printed circuit board mounted on the flat strip;

an elongated, substantially U-shaped lens having a constant cross-section including bulged longitudinal edges having a circular cross-section, the edges slidably engaged with the grooves on the heat sink to form a housing that covers the LEDs;

a sheet of diffusing film inserted between the heat sink and the lens; and

at least one electrical connector in electrical communication with the printed circuit board, the electrical connector attached to an end of the housing.

21. An LED light tube configured to replace a conventional fluorescent light tube in a conventional fluorescent light socket, the LED light tube comprising:

an elongated heat sink having a constant cross-section, the heat sink including two spaced apart longitudinal grooves facing in opposing directions and having a cross-section including a circular portion, a flat strip between the grooves, and a plurality of fins projecting from the heat sink on the opposite side as the flat strip;

a plurality of LEDs in electrical communication with a printed circuit board, the printed circuit board mounted on the flat strip;

an elongated, substantially U-shaped lens having a constant cross-section including bulged longitudinal edges having a circular cross-section, the lens including a bend toward the interior of the light tube near the bulged longitudinal edge, the edges slidably engaged with the grooves in the heat sink to form a housing that covers the LEDs;

a sheet of diffusing film inserted between the heat sink and the lens; and

at least one electrical connector in electrical communication with the printed circuit board, the electrical connector attached to an end of the housing.