Light color and intensity adjustable LED

• US 9,125,272 B2
• Filed: 10/27/2014
• Issued: 09/01/2015
• Est. Priority Date: 05/28/2010
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: TSMC Solid State Lighting Ltd. (Epistar Corporation)
• Inventors: Huang, Hsin-Chieh
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): PHAM, THAI N
• Application Number:
  US14/524,060
• Publication Number:
  US 20150054412A1
• Time in Patent Office: 309 Days
• Field of Search: 315/149, 315/151, 315/185.R, 315/192, 315/291, 315/294, 315/297, 315/307, 315/308, 315/152, 315/312, 345/98, 345/99, 345/102, 345/204, 345/206, 345/207, 345/690
• US Class Current: 1/1
• CPC Class Codes: F21V 23/0457 the sensor sensing the operating status of the lighting device, e.g. to detect failure of a light source or to provide feedback to the device
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/22 using optical feedback

Abstract

A lighting apparatus includes a board, a first light-emitting diode (LED) bank disposed on the board, a second LED bank disposed on the board, a light detector coupled to the first LED bank, and a driver coupled to the light detector and to each of the first and second LED banks. The first LED bank includes a plurality of first LEDs. The second LED bank includes a plurality of second LEDs, and is electrically coupled to the first LED bank. The light detector is configured to detect an output decay of light from each of the first LEDs. The second LEDs in the second LED bank are initially deactivated and are subsequently activated in response to light output decay of the first LEDs.

Claims

1. A lighting apparatus, comprising:

a board;

a first light-emitting diode (LED) bank disposed on the board, the first LED bank including a plurality of first LEDs;

a second LED bank disposed on the board, the second LED bank including a plurality of second LEDs, wherein the second LED bank is electrically coupled to the first LED bank;

a light detector coupled to the first LED bank, wherein the light detector is configured to detect a light output decay from each of the first LEDs; and

a driver coupled to the light detector and to each of the first and second LED banks;

wherein the second LEDs in the second LED bank are initially deactivated and are subsequently activated in response to light output decay of the first LEDs.

2. The lighting apparatus of claim 1, wherein each of the first LEDs is electrically coupled to a counterpart one of the second LEDs.

3. The lighting apparatus of claim 2, wherein in response to a detected light output decay of one of the first LEDs, its counterpart second LED is activated.

4. The lighting apparatus of claim 2, wherein in response to a detected light output decay of one of the first LEDs, a non-counterpart second LED is activated.

5. The lighting apparatus of claim 1, wherein the entire second LED bank is activated in response to the light output decay of the first LEDs.

6. The lighting apparatus of claim 2, wherein the counterpart first and second LEDs are mounted in pairs on the board.

7. The lighting apparatus of claim 1, wherein the light output decay occurs when the light output of any of the first LEDs cannot meet a predefined light output threshold even when driven at a maximum current.

8. A lighting apparatus, comprising:

a board;

a primary light-emitting diode (LED) bank disposed on the board, the primary LED bank including a plurality of primary LEDs;

a backup LED bank disposed on the board, the backup LED bank including a plurality of backup LEDs, wherein each of the primary LEDs is electrically coupled to a respective one of the backup LEDs;

a light detector coupled to the primary LED bank, wherein the light detector is configured to detect a light output decay from each of the primary LEDs; and

a driver coupled to the light detector and to the primary and backup LED banks;

wherein the backup LEDs in the backup LED bank are initially deactivated and are subsequently activated in response to detected light output decay of the primary LEDs.

9. The lighting apparatus of claim 8, wherein in response to a detected light output decay of one of the primary LEDs, its respective backup LED is activated.

10. The lighting apparatus of claim 8, wherein the entire backup LED bank is activated in response to the light output decay of the primary LEDs.

11. The lighting apparatus of claim 8, wherein the light detector detects light output decay when the light output of any of the primary LEDs cannot meet a predefined light output threshold while being driven at a maximum current.

12. The lighting apparatus of claim 8, wherein each primary LED and its respective backup LED electrically coupled thereto are mounted on the board as a pair.

13. A method, comprising:

providing a lighting apparatus that includes a board, a first light-emitting diode (LED) bank disposed on the board, and a second LED bank disposed on the board, the first LED bank and the second LED bank including a plurality of first LEDs and second LEDs, respectively, wherein the second LED bank is electrically coupled to the first LED bank;

activating the first LED bank while deactivating the second LED bank;

thereafter detecting a light output decay from the first LED bank; and

selectively activating one or more of the second LEDs based on the detected light output decay from the first LED bank.

14. The method of claim 13, further comprising:

electrically coupling each of the first LEDs to a counterpart one of the second LEDs.

15. The method of claim 14, wherein the selectively activating comprises activating a counterpart second LED of the first LED whose light output decay has been detected.

16. The method of claim 14, wherein the counterpart first and second LEDs are mounted in pairs on the board.

17. The method of claim 15, wherein the selectively activating further comprises activating one of the second LEDs that is not a counterpart of the first LED whose light output decay has been detected.

18. The method of claim 13, further comprising activating the entire second LED bank based on the detected light output decay from the first LED bank.

19. The method of claim 13, wherein the detecting of the light output decay comprises detecting that a light output of any of the first LEDs fails to meet a predefined light output threshold while being driven at a maximum current.

20. The method of claim 13, wherein the activating of the first LED bank and the selectively activating one or more of the second LEDs comprises driving the first LED bank and driving the one or more of the second LEDs by a driver.