High efficiency LED lamp

• US 10,094,548 B2
• Filed: 07/30/2012
• Issued: 10/09/2018
• Est. Priority Date: 05/09/2011
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Draper, Charles, Wilcox, Kurt, Taylor, Jason, Pickard, Paul Kenneth, Negley, Gerald H., Edmond, Mark
• Primary Examiner(s): RAABE, CHRISTOPHER M
• Application Number:
  US13/561,874
• Publication Number:
  US 20130051002A1
• Time in Patent Office: 2,262 Days
• Field of Search: 36224902
• 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 9/90 Methods of manufacture
• CPC Class Codes: F21V 29/58 characterised by the coolants
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• 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 29/773 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21V 3/06 characterised by the material
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2105/12 characterised by the geometrical disposition of the light-generating elements, e.g. arranging light-generating elements in differing patterns or densities
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

A high-efficiency LED lamp is disclosed. Embodiments of the invention provide a high-efficiency, high output solid-state lamp. The lamp includes an LED assembly, an optical element disposed to receive light from the LED assembly, and an optical overlay. The optical element includes a primary exit surface, wherein the primary exit surface is at least about 1.5 inches from the LED assembly. In example embodiments, the optical element is roughly cylindrical in shape, but can take other shapes and be made from various materials. An LED lamp according to some embodiments of the invention has an efficiency of at least about 160 lumens per watt. In some embodiments, the lamp has a light output of at least 1200 lumens. In some embodiments, the LED lamp produces light with a color rendering index (CRI) of at least 90 and a warm white color.

Claims

1. An LED lamp comprising:

a plurality of LEDS, each of the plurality of LEDs comprising an at least 1.4mm square LED chip die;

a diffuser including a cylindrical surface defining a first end and a second end and a primary exit surface through which light exits the LED lamp, the primary exit surface closing the first end of the cylindrical surface and being substantially flat over its entire area, wherein the primary exit surface is spaced between about 1.5 and about 8 inches from the plurality of LEDs; and

a flat, reflective, annular-shaped member surrounding and external to the diffuser, the flat, reflective, annular-shaped member being disposed adjacent the second end and being exposed to light emitted from the diffuser to reflect the light;

wherein the lamp produces at least 170 Lumens per Watt.

2. The LED lamp of claim 1 wherein the plurality of LEDS further comprises at least two groups of LEDs, wherein one group, when illuminated, emits light having a dominant wavelength from 435 to 490 nm, and another group, when illuminated, emits light having a dominant wavelength from 600 to 640 nm, one group being packaged with a phosphor, which, when excited, emits light having a dominant wavelength from 540 to 585 nm.

3. The LED lamp of claim 2 wherein the one group, when illuminated, emits light having a dominant wavelength from 440 to 480 nm, the other group, when illuminated, emits light having a dominant wavelength of about 610 nm, and the phosphor, when excited, emits light having a dominant wavelength from 560 to 580 nm.

4. An LED lamp comprising:

an LED assembly including at least first and second LEDs operable to emit light of at least two different colors;

a cylindrical optical element disposed to receive light from the LED assembly, the optical element including a cylindrical curved surface defining a first end and a second end and a primary exit surface through which light exist the LED lamp, the primary exit surface closing the first end of the cylindrical curved surface and being substantially flat over its entire area, and the primary exit surface spaced at least about 1.5 inches from the LED assembly; and

a flat, white reflective, annular-shaped member surrounding and external to the optical element and the LED assembly, the flat, white reflective, annular shaped member being disposed adjacent the second end and being exposed to light emitted from the optical element to reflect the light;

wherein the lamp produces at least 170 Lumens/Watt.

5. The LED lamp of claim 4 wherein the first and second LEDs, when illuminated, emit light having a dominant wavelength from 435 to 490 nm and a dominant wavelength from 600 to 640 nm, respectively, and at least one of the first and second LEDs is packaged with a phosphor, which, when excited, emits light having a dominant wavelength from 540 to 585 nm.

6. The LED lamp of claim 5 wherein the first and second LEDs, when illuminated, emit light having a dominant wavelength from 440 to 480 nm, and a dominant wavelength of about 610 nm, respectively and the phosphor, when excited, emits light having a dominant wavelength from 560 to 580 nm.

7. The LED lamp of claim 4 further comprising a heatsink adjacent to the flat, white reflective, annular-shaped member, the heatsink including a plurality of substantially white fins.

8. The LED lamp of claim 7 wherein the primary exit surface is spaced from about 1.5 to about 8 inches away from the LED assembly.

9. The LED lamp of claim 8 further comprising a power supply portion including a power supply in thermal communication with the heatsink and electrically connected to the LED assembly.

10. The LED lamp of claim 9 wherein the LED assembly further comprises:

a plurality of red-emitting LED devices; and

a plurality of blue-shifted-yellow (BSY) emitting LED devices.

11. The LED lamp of claim 10 wherein the plurality of each of the red-emitting LED devices and BSY-emitting LED devices comprises at least 12 LED devices.

12. The LED lamp of claim 11 wherein the plurality of the red-emitting LED devices comprises 13 LED devices and the plurality of BSY-emitting LED devices comprises 31 LED devices.

13. A method of assembling a high-efficiency LED lamp, the method comprising:

providing an LED assembly comprising a plurality of LEDs mounted on a flat carrier;

connecting the LED assembly to a line-voltage power supply;

providing a heatsink in thermal communication with at least one of the line-voltage power supply and the LED assembly;

installing a flat, white reflective, annular-shaped member adjacent to the heatsink; and

installing a cylindrical optical element disposed to receive light from the LED assembly, the optical element including a cylindrical surface defining a first end and a second end and a primary exit surface through which light exits the LED lamp, the primary exit surface closing the first end of the cylindrical surface and being substantially flat over its entire area and being substantially parallel to the carrier over its entire area, the optical element being positioned so that the flat, reflective, white reflective, annular-shaped member is external to and surrounds the optical element adjacent the second end and is exposed to light emitted from the diffuser to reflect the light., the primary exit surface also positioned so that the primary exit surface is spaced at least about 1.5 inches from the LED assembly wherein the lamp produces at least 170 Lumens/Watt.

14. The method of claim 13 wherein the primary exit surface is spaced from about 1.5 to about 8 inches away from the LED assembly.

15. The method of claim 14 wherein the providing of the LED assembly further comprises:

providing first and second LEDs operable to emit light of at least two different colors; and

packaging one of the first and second LEDs with a phosphor.

16. The method of claim 15 wherein the first and second LEDs, when illuminated, emit light having a dominant wavelength from 435 to 490 nm and a dominant wavelength from 600 to 640 nm, respectively, and the phosphor, when excited, emits light having a dominant wavelength from 540 to 585 nm.

17. The method of claim 16 wherein the first and second LEDs, when illuminated, emit light having a dominant wavelength from 440 to 480 nm, and a dominant wavelength of about 610 nm, respectively and the phosphor, when excited, emits light having a dominant wavelength from 560 to 580 nm.

18. An LED lamp comprising:

a plurality of LEDs mounted on a flat carrier, wherein the plurality of LEDS comprises at least two groups of LEDs, wherein one group, when illuminated, emits light having a dominant wavelength from 435 to 490 nm, and another group, when illuminated, emits light having a dominant wavelength from 600 to 640 nm, one group being packaged with a phosphor, which, when excited, emits light having a dominant wavelength from 540 to 585 nm, the plurality of LEDs each having a square area of approximately 2.0 mm²;

a heat sink thermally coupled to the plurality of LEDs;

a diffuser including a curved cylindrical surface defining a first end and a second end and a primary exit surface through which light exits the LED lamp, the primary exit surface closing the first end of the curved cylindrical surface and being substantially parallel to the carrier over its entire area such that a primary portion of the light from the plurality of LEDs reflects off of the cylindrical surface and exits the lamp through the primary exit surface, the primary exit surface spaced at least 1.5 inches from the LED assembly; and

a flat, reflective, annular-shaped member surrounding and external to the diffuser, the flat, reflective, annular-shaped member being disposed adjacent the second end for reflecting light emitted from the diffuser,

whereby the lamp produces at least 1200 Lumens with a CRI of at least 90 with a luminous efficacy of at least 170 Lumens per Watt.