Electric shock resistant L.E.D. based light

• US 8,807,785 B2
• Filed: 01/16/2013
• Issued: 08/19/2014
• 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): BANNAN, JULIE A
• Application Number:
  US13/742,678
• Publication Number:
  US 20130128574A1
• Time in Patent Office: 580 Days
• Field of Search: 36221701-219, 36221712-21717
• 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

An LED-based light comprises: a tubular housing formed of a high-dielectric material and defined at least in part by a light transmitting portion; an elongate circuit board disposed within the housing; at least one LED mounted on 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, substantially all of the radially outer surface of the heat sink in thermally conductive relation with the tubular housing for electrically insulated thermal transmission of heat generated by the LED from the circuit board to an ambient environment surrounding the LED-based light; and a pair of end caps disposed on opposing ends of the housing with connectors configured to physically connect the LED-based light to a conventional fluorescent light fixture.

Claims

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

a tubular housing formed of a high-dielectric material and defined at least in part by a light transmitting portion;

an elongate circuit board disposed within the housing;

at least one LED mounted on the circuit board;

an elongate heat sink disposed within the housing, the heat sink having a circuit board mounting surface opposing a radially outer surface, the circuit board mounted in thermally conductive relation to the circuit board mounting surface, substantially all of the radially outer surface of the heat sink in thermally conductive relation with the tubular housing for electrically insulated thermal transmission of heat generated by the at least one LED from the circuit board to an ambient environment surrounding the LED-based light, wherein the housing 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 engage the at least one projection to attach the heat sink to the housing; and

a pair of end caps disposed on opposing ends of the housing, each end cap including at least one connector configured to physically connect the LED-based light to the fluorescent light fixture.

2. The LED-based light of claim 1, wherein the housing is configured to isolate the radially outer surface of the heat sink from the ambient environment surrounding the LED-based light 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.

3. The LED-based light of claim 1, wherein the housing has a substantially continuous circular cross section along a length of the housing.

4. The LED-based light of claim 1, wherein a plurality of LEDs are mounted along a length of the circuit board at predetermined intervals for uniformly emitting light through the light transmitting portion.

5. The LED-based light of claim 1, further comprising:

a lens positioned between the at least one LED and the light transmitting portion.

6. The LED-based light of claim 5, wherein the lens is configured to diffuse a light generated by the at least one LED.

7. The LED-based light of claim 1, wherein the heat sink is composed of an electrically conductive material.

8. The LED-based light of claim 1, wherein at least a portion of the housing that is in the thermally conductive relation with the radially outer surface of the heat sink is composed of a low thermally conductive material.

9. The LED-based light of claim 1, wherein the housing is composed of one of a polycarbonate, acrylic or glass material.

10. The LED-based light of claim 1, wherein the at least one connector is further configured to electrically connect the at least one LED to the fluorescent light fixture.

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

12. An LED-based light for replacing a conventional fluorescent tube in a conventional fluorescent light fixture, the LED-based light comprising:

a tubular housing formed of a high-dielectric material, the housing having a substantially continuous circular cross section and defined at least in part by a light transmitting portion;

an elongate circuit board disposed within the housing;

at least one LED mounted on the circuit board;

an elongate heat sink disposed within the housing, the heat sink having a circuit board mounting surface opposing a radially outer surface, the circuit board mounted in thermally conductive relation to the circuit board mounting surface, the housing contoured to the radially outer surface and attached in thermally conductive relation to the radially outer surface to 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, wherein the housing 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 engage the at least one projection to attach the heat sink to the housing;

a light diffusing lens positioned between the at least one LED and the light transmitting portion; and

a pair of end caps disposed on opposing ends of the housing, each end cap including at least one connector configured to physically connect the LED-based light to the fluorescent light fixture.

13. The LED-based light of claim 12, wherein a plurality of LEDs are mounted along a length of the circuit board at predetermined intervals for uniformly emitting light through the light transmitting portion.

14. The LED-based light of claim 12, wherein the heat sink is composed of an electrically conductive material.

15. The LED-based light of claim 12, wherein a portion of the housing that is in the thermally conductive relation with the radially outer surface of the heat sink is composed of a low thermally conductive material.

16. The LED-based light of claim 12, wherein the housing is composed of one of a polycarbonate, acrylic or glass material.

17. The LED-based light of claim 12, wherein the at least one connector is a bi-pin connector further configured to electrically connect the at least one LED to the conventional fluorescent light fixture.