Systems and methods for high output, high color quality light

Patent metadata

Field	Value
Publication number	US-10045418-B2
Application number	US-201715421999-A
Country	US
Kind code	B2
Filing date	Feb 1, 2017
Priority date	Apr 4, 2008
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

Systems and methods for a high output, high color quality light are disclosed. In some embodiments, such a light may include a light fixture including one or more LEDs configured to output a cumulative light output; wherein the cumulative light output comprises an intensity of greater than or equal to 10,000 lumens; and wherein the cumulative light output comprises a CRI of at least 90.

First claim

What is claimed:

1. A light fixture comprising:
a plurality of LEDs configured to output a cumulative light output;
a current control device configured to control a drive current provided to the plurality of LEDs, wherein the drive current comprises at least 700 mA; and
wherein the cumulative light output comprises an intensity of greater than or equal to 10,000 lumens and a color temperature of greater than or equal to 4000° K.

2. The light fixture of claim 1 , wherein the a plurality of LEDs comprise two or more strings of LEDs.

3. The light fixture of claim 2 , wherein at least two of the two or more strings of LEDs comprise different color LEDs.

4. The light fixture of claim 3 , wherein at least one of the strings comprises a Blue Shifted Yellow String and at least one of the strings comprises a Red String.

5. The light fixture of claim 3 , wherein each of the strings comprises a Blue Shifted Yellow String with a different color temperature.

6. The light fixture of claim 3 , wherein the two or more strings of LEDs comprise a first string of LEDs and a second string of LEDs connected in parallel with the first string of LEDs, and wherein the light fixture further comprises:
a first current control device connected in series with the first string of LEDs;
a second current control device connected in series with the second string of LEDs;
a first voltage measurement device coupled to the first string of LEDs and the second string of LEDs, the first voltage measurement device coupled to the first current control device and configured to control the first current control device; and
a second voltage measurement device coupled to the first string of LEDs and the second string of LEDs, the second voltage measurement device coupled to the second current control device and configured to control the second current control device.

7. The light fixture of claim 6 , wherein each of the first and second current control devices comprise: a Bipolar Junction Transistor (BJT); a MOSFET; a junction gate field-effect transistor (JFET); or an insulated gate field effect transistor (IGFET).

8. The light fixture of claim 7 , wherein each of the first and second voltage measurement devices comprise: a comparator and an op-amp.

9. The light fixture of claim 6 , further comprising a third string of LEDs connected in series with the first and second string of LEDs.

10. The light fixture of claim 6 , further comprising:
a pulse generator;
an RC circuit coupled to the pulse generator; and
a third current control device coupled to the RC circuit, the third current control device configured to vary the voltage measured by the second voltage measurement device.

11. The light fixture of claim 1 , further comprising:
a plurality of heat-sink-mounted LED array modules, each module engaging an LED-adjacent surface of a heat-sink base for transfer of heat from the module;
a heat-sink heat-dissipating surface extending away from the modules;
at least one venting aperture through the heat-sink base to provide air ingress to the heat-dissipating surfaces adjacent to the aperture.

12. The light fixture of claim 1 , further comprising:
a housing and an LED assembly secured with respect thereto and open to permit air/water-flow over the LED assembly, the LED assembly comprising:
an LED-array;
an extruded heat sink that has a base and heat-transfer surfaces extending from the base, wherein the heat-transfer surfaces are surfaces of a plurality of fins extending away from the base in a first direction, the fins including first and second fins along the opposite edges of the base, the first and second edge-adjacent fins also extending from the base in a second direction opposite to the first direction.

13. A light fixture comprising:
a plurality of LEDs configured to output a cumulative light output at an efficiency;
a current control device configured to control a drive current provided to the plurality of LEDs, wherein the drive current comprises at least 700 mA; and
wherein the cumulative light output comprises an intensity of greater than or equal to 10,000 lumens and a color temperature of greater than or equal to 4000° K.

14. The light fixture of claim 13 , wherein the a plurality of LEDs comprise two or more strings of LEDs.

15. The light fixture of claim 14 , wherein the two or more strings of LEDs comprise a first string of LEDs and a second string of LEDs connected in parallel with the first string of LEDs, and wherein the light fixture further comprises:
a first current control device connected in series with the first string of LEDs;
a second current control device connected in series with the second string of LEDs;
a first voltage measurement device coupled to the first string of LEDs and the second string of LEDs, the first voltage measurement device coupled to the first current control device and configured to control the first current control device; and
a second voltage measurement device coupled to the first string of LEDs and the second string of LEDs, the second voltage measurement device coupled to the second current control device and configured to control the second current control device.

16. The light fixture of claim 15 , wherein each of the first and second current control devices comprise: a Bipolar Junction Transistor (BJT); a MOSFET; a junction gate field-effect transistor (JFET); or an insulated gate field effect transistor (IGFET).

17. The light fixture of claim 16 , wherein each of the first and second voltage measurement devices comprise: a comparator and an op-amp.

18. The light fixture of claim 15 , further comprising a third string of LEDs connected in series with the first and second string of LEDs.

19. The light fixture of claim 15 , further comprising:
a pulse generator;
an RC circuit coupled to the pulse generator; and
a third current control device coupled to the RC circuit, the third current control device configured to vary the voltage measured by the second voltage measurement device.

20. The light fixture of claim 13 , further comprising:
a plurality of heat-sink-mounted LED array modules, each module engaging an LED-adjacent surface of a heat-sink base for transfer of heat from the module;
a heat-sink heat-dissipating surfaces extending away from the modules;
at least one venting aperture through the heat-sink base to provide air ingress to the heat-dissipating surfaces adjacent to the aperture.

21. The light fixture of claim 13 , further comprising:
a housing and an LED assembly secured with respect thereto and open to permit air/water-flow over the LED assembly, the LED assembly comprising:
an LED-array;
an extruded heat sink that has a base and heat-transfer surface extending from the base, wherein the heat-transfer surfaces are surfaces of a plurality of fins extending away from the base in a first direction, the fins including first and second fins along the opposite edges of the base, the first and second edge-adjacent fins also extending from the base in a second direction opposite to the first direction.

22. The light fixture of claim 1 , wherein the cumulative light output comprises an intensity from 10,000 lumens to 74,468 lumens.

23. The light fixture of claim 1 , wherein the light fixture is configured to operate based on a drive current comprising a current from 700 mA to 1000 mA.

24. The light fixture of claim 1 , wherein the cumulative light output comprises a total r

Assignees

• Cree Inc

Inventors

• Kinnune Brian
• Goelz David
• Lay James
• Miletich Don
• Ruud Alan
• Wilcox Kurt
• Hu Yuequan
• Ni Liqin
• Medendorp Jr Nicholas William
• Karpichev Boris

Classifications

• H05B45/46

  having LEDs disposed in parallel lines · CPC title

• F21V23/007

  enclosed in a casing · CPC title

• F21V29/74

  with fins or blades · CPC title

• F21Y2115/10

  Light-emitting diodes [LED] · CPC title

• F21W2131/103

  of streets or roads · CPC title