Electric shock resistant L.E.D. based light

• US 8,360,599 B2
• Filed: 05/23/2008
• Issued: 01/29/2013
• Est. Priority Date: 05/23/2008
• Status: Active Grant

• Current Assignee: Ilumisys Incorporated (Altair Engineering Incorporated)
• Original Assignee: Ilumisys Incorporated (Altair Engineering Incorporated)
• Inventors: Ivey, John, Siemiet, Dennis
• Primary Examiner(s): CROWE, DAVID R
• Application Number:
  US12/126,579
• Publication Number:
  US 20090290334A1
• Time in Patent Office: 1,712 Days
• Field of Search: 362/218, 362/221, 362/222, 362/223, 362/225, 362/217.1, 362/240, 362/249.02, 362/249.06
• 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: F21K 9/69 Details of refractors forming part of the light source
• CPC Class Codes: F21V 23/06 the elements being coupling devices , e.g. connectors
• CPC Class Codes: F21V 25/00 Safety devices structurally associated with lighting devices gas- tight or water-tight arrangements F21V31/00; in general F16P; protective circuit arrangements per se H02H7/00
• CPC Class Codes: F21V 29/506 of globes, bowls or cover glasses
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• 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 29/89 Metals
• 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-based replacement light for a fluorescent socket is constructed such that an entirety of a radially outer portion of a tubular housing at least partially defined by a high-dielectric light transmitting portion is formed of a high-dielectric material. Forming a radially outer portion of the tubular housing of a high-dielectric material prevents a person handling the light from being shocked as a result of capacitive coupling occurring when the LED-based replacement light is installed one end at a time. A circuit board is in thermally conductive relation with the tubular housing, allowing for conduction of heat generated by the LEDs from a side of circuit board opposite the LEDs to the tubular housing for dissipation to the ambient environment.

Claims

1. An LED-based light for replacing a conventional fluorescent tube comprising:

an elongated highly thermally conductive heat sink having a radially outer portion;

an elongated high-dielectric lens engaging the heat sink and forming a first portion of a housing for the LED-based light;

a high-dielectric cover engaging the heat sink and overlaying substantially all of the radially outer portion of the heat sink to form a second portion of the housing for the LED-based light separate from the first portion such that the cover isolates the radially outer portion of the heat sink from an ambient environment surrounding the LED-based light;

a plurality of 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 an arc of the lens, the circuit board mounted directly to the heat sink on a surface opposing the radially outer portion of the heat sink with the primary heat transferring side of the circuit board in thermally conductive relation with the heat sink and substantially all of the radially outer portion of the heat sink in thermally conductive relation with the high-dielectric cover for highly electrically insulated thermal transmission of heat generated by the LEDs from the circuit board to the ambient environment surrounding the LED-based light; and

a pair of end caps disposed on the opposite ends of the housing, at least one end cap carrying at least one connector configured to electrically connect the LEDs to an existing fixture.

2. The LED-based light of claim 1, wherein the cover includes at least one projection having a rounded end on an interior portion thereof and the radially outer portion of the heat sink includes at least one corresponding groove configured to attach the cover to the heat sink.

3. The LED-based light of claim 1, wherein the exterior of the cover is configured to highly insulate a portion of the housing from a charge occurring as a result of parasitic capacitive coupling between the heat sink and the circuit board as a result of high-frequency starting voltage designed for starting a conventional fluorescent tube being applied across the circuit board.

4. The LED-based light of claim 1, wherein the lens and the cover define an entire exterior of the housing.

5. The LED-based light of claim 1, wherein the at least one connector is a bi-pin connector.

6. An LED-based light for replacing a conventional fluorescent tube comprising:

a housing including a light transmitting high dielectric lens and a high dielectric cover separate from the lens, the lens and the cover forming an exterior of the housing;

an elongate circuit board disposed within the housing;

a plurality of LEDs mounted along a length of the circuit board;

an elongate heat sink disposed within the housing, the heat sink having an interior circuit board mounting surface opposing a radially outer surface, the circuit board mounted in thermally conductive relation to the circuit board mounting surface, the cover contoured to the radially outer surface and attached in thermally conductive relation to the radially outer surface to directly isolate the radially outer surface from an ambient environment exterior of the housing from a charge occurring in the heat sink as a result of parasitic capacitive coupling between the heat sink and the circuit board resulting from a high-frequency starting voltage designed for starting a conventional fluorescent tube being applied across the circuit board while transmitting heat from the radially outer surface to the ambient environment, and the lens attached to the heat sink and extending adjacent to the LEDs such that light generated by the LEDs transmitted through an arc of the lens; and

a pair of end caps disposed on opposing ends of the housing, each end cap including at least one connector configured to physically and electrically connect the LEDs to a conventional fluorescent light fixture.

7. The LED-based light of claim 6, wherein the LEDs are mounted along the length of the circuit board at predetermined intervals for uniformly emitting light through the arc of the lens.

8. The LED-based light of claim 6, wherein the cover includes at least one projection having a rounded end on an interior portion thereof and the radially outer surface of the heat sink includes at least one corresponding groove configured to attach the cover to the heat sink.

9. The LED-based light of claim 6, wherein the cover is composed from a low thermally conductive material.

10. The LED-based light of claim 6, wherein the cover is composed from one of a polycarbonate, acrylic or glass material.