LIGHT EMITTING DIODE LIGHTING DEVICE

• US 20090195186A1
• Filed: 02/04/2009
• Published: 08/06/2009
• Est. Priority Date: 02/06/2008
• Status: Active Grant

• Current Assignee: C Crane Company Incorporated
• Original Assignee: C Crane Company Incorporated
• Inventors: Johansen, Jarl J., Guest, Ralph E., Nelson, Theodore G.
• Granted Patent: US 8,274,241 B2
• Time in Patent Office: Days
• US Class Current: 315/294
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/238 Arrangement or mounting of circuit elements integrated in the light source
• CPC Class Codes: F21V 17/164 the parts being subjected to bending, e.g. snap joints
• CPC Class Codes: F21V 23/002 Arrangements of cables or conductors inside a lighting device, e.g. means for guiding along parts of the housing or in a pivoting arm
• CPC Class Codes: F21V 23/006 the substrate being distinct from the light source holder
• CPC Class Codes: F21V 29/77 with essentially identical diverging planar fins or blades, e.g. with fan-like or star-like cross-section
• CPC Class Codes: F21V 3/061 the material being glass
• CPC Class Codes: F21V 3/062 the material being plastics
• CPC Class Codes: F21Y 2107/40 on the sides of polyhedrons, e.g. cubes or pyramids
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/32 Pulse-control circuits
• CPC Class Codes: H05B 45/355 Power factor correction [PFC]; Reactive power compensation
• CPC Class Codes: H05B 45/3577 Emulating the dimming characteristics, brightness or colour temperature of incandescent lamps
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/56 involving measures to prevent abnormal temperature of the LEDs
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A lighting device comprises a mounting head having multiple facets each configured to retain an associated Light Emitting Diode (LED). The LEDs are mounted to the facets with a thermally conductive metal pad and thermally conductive adhesive. A connector for the lighting device inserts into a light socket and receives power for operating the LEDs. A heat transfer body is coupled between the mounting head and the connector and transfer heat generated by the LEDs downward from the mounting head and then radially outward. The mounting head, adhesive, metal pad, and heat transfer body form a heat transfer structure that more effectively removes heat generated by the LEDs. In one embodiment, a dimmer circuit is also provided that allows the LED lighting device to operate with conventional dimmer switches.

Claims

1. A lighting device, comprising:

a mounting head having multiple facets each configured to retain an associated Light Emitting Diode (LED), the facets having upwardly inclining angles that extend radially outward;

a light cover extending over the mounting head;

a connector configured to insert into a light socket and receive power for operating to the LEDs; and

a heat transfer body located between the mounting head and the connector configured to transfer heat generated by the LEDs downward and outward from the mounting head.

2. The lighting device according to claim 1 wherein the heat transfer body has a continuous outside surface that extends from the mounting head to the connector for radiating heat radially away from the lighting device.

3. The lighting device according to claim 2 wherein the heat transfer body includes elongated ridges that are extend vertically along substantially an entire vertical length of the outside surface of the heat transfer body, the ridges also extending radially around the outside surface of the heat transfer body.

4. The lighting device according to claim 1 wherein the facets located on sides of the mounting head each have an incline angle of and a top facet located on a top surface of the mounting head is substantially horizontal.

5. The lighting device according to claim 1 further comprising a metal thermal transfer pad coupled between the facets and the associated LEDs.

6. The lighting device according to claim 5 further comprising a thermally conductive adhesive configured to provide a thermally conductive path between the metal thermal transfer pad and the facets.

7. The lighting device according to claim 6 wherein the thermally conductive adhesive is glue with high thermal conductivity, high electrical insulation, and low out gassing.

8. The lighting device according to claim 1 wherein the mounting head and heat transfer body integrally formed from a continuous piece of material that includes a center cavity that extends from the connector up to the mounting head.

9. The lighting device according to claim 8 further comprising a controller that inserts up into the cavity, the controller including a dimmer circuit for dimming the LEDs.

10. A control circuit for a lighting devices comprising:

Light Emitting Diodes (LEDs);

a rectifier circuit for converting an Alternating Current (AC) power source into a Direct Current (DC) power source;

a power conditioning circuit coupled across the rectifier circuit and configured to condition the DC power source;

a controller configured to monitor a reference signal corresponding with the DC power source and generate pulses according to the reference signal that enable current from the DC power source to activate the LEDs; and

a dimmer circuit configured to reduce the reference signal and cause the controller to reduce a duty cycle of the generated pulses that reduce an amount of light generated by the LEDs.

11. The control circuit according to claim 10 further comprising a low pass filter coupled to the dimmer circuit configured to delay a time response for changing the reference signal.

12. The control circuit according to claim 10 wherein the dimmer circuit reduces an amount of light output by the LEDs responsive to a conventional incandescent light dimmer switch until the LEDs are substantially turned off causing the control circuit to operate with the dimmer circuit in a manner similar to an incandescent light bulb.

13. The control circuit according to claim 10 wherein the dimmer circuit comprises:

a diode coupled across the rectifier circuit and configured to generate a negative voltage; and

a voltage divider coupled between the diode and the controller and configured to reduce the reference signal monitored by the controller.

14. The control circuit according to claim 13 wherein the voltage divider comprises:

a first resistor coupled at a first end to a first end of the diode and coupled at a second end to a voltage monitoring input of the controller;

a second resistor coupled at a first end to a second end of the diode and coupled at a second end to the voltage monitoring input of the controller; and

a third resistor coupled at a first end to the rectifier circuit and coupled at a second end to the voltage monitoring input of the controller.

15. The control circuit according to claim 14 further comprising a delay capacitor coupled at a first end to the second end of the diode and coupled at a second end to the voltage monitoring input of the controller.

16. The control circuit according to claim 15 wherein the delay capacitor and the third resistor cause the control circuit to appear more inductive and change a power factor toward one when powering the LEDs.

18. The lighting device according to claim 19 further comprising elongated ridges that are extend vertically along substantially an entire vertical length of the outside surface of the heat transfer body, the ridges also extending radially around the outside surface of the heat transfer body.

19. The lighting device according to claim 16 wherein the mounting head and the heat transfer body are integrally formed together for aluminum and a thermally conductive adhesive is used to attach the LEDs to the mounting head.

17. A Light Emitting Diode (LED) lighting device, comprising:

a mounting head configured to hold multiple different LEDs radially around a top end of the lighting device; and

a heat transfer body extending from the mounting head down to the connector and having an outside surface that transfers heat generated by the LEDs radially out and 360 degrees around a bottom portion of the lighting device.