D-SHAPED CROSS SECTION L.E.D. BASED LIGHT

• US 20100220469A1
• Filed: 05/12/2010
• Published: 09/02/2010
• Est. Priority Date: 05/23/2008
• Status: Abandoned Application

• Current Assignee: Ilumisys Incorporated (Altair Engineering Incorporated)
• Original Assignee: Altair Engineering Incorporated
• Inventors: Amrine, James, Ivey, John
• Application Number:
  US12/778,612
• Publication Number:
  US 20100220469A1
• Time in Patent Office: Days
• US Class Current: 362/218
• CPC Class Codes: F21K 9/27 Retrofit light sources for lighting devices with two fittings for each light source, e.g. for substitution of fluorescent tubes
• CPC Class Codes: F21V 29/507 of means for protecting lighting devices from damage, e.g. housings
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/75 with fins or blades having different shapes, thicknesses or spacing
• CPC Class Codes: F21V 29/763 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 7/0058 adapted to cooperate with light sources of shapes different from point-like or linear, e.g. circular light sources
• 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]
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A LED-based replacement light for a fluorescent socket is constructed such that a tubular housing has a D-shaped cross section with a flat base with opposing longitudinal edges, opposing sides extending generally perpendicular to the flat base from the opposing longitudinal edges, and a curved surface spanning the opposing sides opposite the flat base. A circuit board structure defines a LED-mounting side with multiple LEDs mounted on the LED-mounting side at predetermined intervals along a length of the circuit board, with at least areas of a primary heat transferring side directly underlying the respective LEDs in thermally conductive relation with the tubular housing for highly electrically insulated thermal transmission of heat generated by the multiple LEDs from the circuit board to an ambient environment surrounding an exterior of the tubular housing. At least one electrical connector is at a longitudinal end of the housing in electrical communication with the circuit board.

Claims

1. A LED-based light for replacing a conventional fluorescent light bulb in a fluorescent light fixture, the LED-based light comprising:

an elongate housing having a D-shaped cross section with a flat base having opposing longitudinal edges, opposing sides extending generally perpendicular to the flat base from the opposing longitudinal edges, and a curved surface spanning the opposing sides opposite the flat base;

multiple LEDs;

a circuit board structure defining a LED-mounting side and a primary heat transferring side opposite the LED-mounting side, the multiple LEDs mounted on the LED-mounting side at predetermined intervals along a length of the circuit board for emitting light through at least the curved surface of the elongate housing; and

at least one electrical connector at a longitudinal end of the tubular housing in electrical communication with the circuit board.

2. The LED-based light of claim 1, wherein at least a portion of an internal surface of each opposing side has a reflector.

3. The LED-based light of claim 1, wherein at least a portion of an internal surface of the curved surface has a diffuser.

4. The LED-based light of claim 1, wherein the primary heat transferring side of the circuit board directly underlying the respective LEDs is in thermally conductive relation with the elongate housing through a highly thermally conductive heat spreader positioned between at least one of the areas of the primary heat transferring side directly underlying the respective LEDs and the flat base of the elongate housing.

5. The LED-based light of claim 4, wherein the heat spreader is a monolithic mass extending substantially the length of the circuit board for conduction between all of the areas of the primary heat transferring side directly underlying the respective LEDs and the flat base of the elongate housing.

6. The LED-based light of claim 4, wherein the heat spreader is one of multiple discrete heat spreaders spaced at the predetermined intervals along the length of circuit board for conduction between one of the areas of the primary heat transferring side directly underlying the respective LEDs and the flat base of the elongate housing.

7. The LED-based light of claim 1, wherein at least the curved surface of the elongate housing is formed of a high-dielectric light transmitting material.

8. The LED-based light of claim 1, further comprising a highly thermally conductive heat sink extending substantially a length of the elongate housing.

9. The LED-based light of claim 8, wherein a lens defines the opposing sides and the curved surface of the D-shaped cross section of the elongate housing and the heat sink defines the flat base.

10. The LED-based light of claim 8, wherein the heat sink is made entirely of a high-dielectric, highly thermally conductive material.

11. The LED-based light of claim 8, wherein the thermally conductive relation includes conduction between the entire primary heat transferring side of the circuit board and a planar, interior surface of the heat sink extending substantially a length of the elongate housing along the flat base.

12. The LED-based light of claim 8, further comprising a covering overlying an outward facing portion of the heat sink, and wherein a lens defines the opposing sides and the curved surface of the D-shaped cross section of the elongate housing and the covering defines the flat base.

13. The LED-based light of claim 1, wherein the at least one electrical connector includes two bi-pin electrical connectors, one attached to each end of the tubular housing.

14. The LED-based light of claim 1, wherein each opposing side of the elongate housing includes at least one longitudinal tab projecting inward and configured to engage the LED-mounting side of the circuit board for securing the circuit board.

15. The LED-based light of claim 1, wherein the multiple LEDs are high-powered LEDs.

16. The LED-based light of claim 15, wherein the multiple LEDs include approximately thirty to sixty LEDs.

17. The LED-based light of claim 16, wherein the LEDs are arranged longitudinally along the circuit board and thermally bonded thereto, the spacing of the LEDs being such as to uniformly and fully occupy a length of the elongate housing.

18. A replacement light for a conventional fluorescent tube light usable in a conventional fluorescent fixture comprising:

a generally tubular body forming the outer surface of the light over substantially its entire length, the tubular body having a D-shaped cross section with a flat base with opposing longitudinal edges, opposing sides extending generally perpendicular to the flat base from the opposing longitudinal edges, and a curved surface spanning the opposing sides opposite the flat base;

a circuit board structure disposed within the tubular body along the flat base and thermally joined thereto while being electrically insulated therefrom;

a pair of end caps disposed on the opposite ends of the tubular body and carrying bi-pin connectors; and

an array of LEDs arranged longitudinally along the circuit board and thermally bonded thereto, the number and spacing of the LEDs being such as to uniformly and fully occupy the space between the end caps, wherein the tubular body is translucent at least in part so as to permit the transmission of light from the LEDs through the tubular body, and wherein at least some of the connectors on the end caps are electrically connected to the LEDs.

19. The replacement light of claim 18, further comprising reflectors positioned along at least a part of each opposing side.

20. A LED-based light for replacing a conventional fluorescent tube comprising:

an elongated housing having a D-shaped cross section with a flat base with opposing longitudinal edges, opposing sides extending generally perpendicular to the flat base from the opposing longitudinal edges, and a curved surface spanning the opposing sides opposite the flat base;

an elongated highly thermally conductive heat sink disposed along the flat base within the housing;

an array of high-power LEDs;

a circuit board structure extending substantially the length of the heat sink, the circuit board defining a LED-mounting side of the circuit board and a primary heat transferring side of the circuit board opposite the LED-mounting side, the LEDs mounted on the LED-mounting side at predetermined intervals along the length of the circuit board for uniformly emitting light through the curved surface of the housing, the circuit board mounted to the heat sink with the primary heat transferring side of the circuit board in thermally conductive relation with the heat sink;

a light diffusing lens positioned between the circuit board and the curved surface;

reflectors positioned along at least a portion of each opposing side of the housing; and

a pair of end caps disposed on the opposite ends of the housing and carrying bi-pin connectors, at least some of the connectors on the end caps electrically connected to the LEDs.