AC Direct Drive Lighting System for Providing Uniform Light Distribution

• US 20150137696A1
• Filed: 11/19/2014
• Published: 05/21/2015
• Est. Priority Date: 11/20/2013
• Status: Active Grant

• Current Assignee: Altoran Chips & Systems, Inc.
• Original Assignee: Altoran Chips & Systems, Inc.
• Inventors: Jeong, Jae Hong, Kim, Minjong, Moon, Kyeongtae, Chen, Weifeng, Jeong, Juhwan
• Granted Patent: US 9,386,644 B2
• Time in Patent Office: Days
• US Class Current: 315/250
• CPC Class Codes: H05B 45/44 with an active control inside an LED matrix

Abstract

An AC lighting system for providing uniform light distribution is disclosed. According to one embodiment, the AC lighting system includes an AC driver and LED packages electrically connected to the AC driver. Each LED package includes a plurality of LED elements and is physically distributed over an illuminating surface of the AC lighting system. The AC driver has a first current sink that drives a first LED group and a second current sink that drives the first LED group and a second LED group. The first LED group includes at least one LED element from each of the LED packages, and the second LED group includes at least one LED element other that the first set of LED elements from each of the LED packages.

Claims

1. An alternating current (AC) lighting system comprising:

an AC power source;

a plurality of LED packages, each of the LED packages includes a plurality of LED elements, the plurality of LED packages are physically distributed over an illuminating surface of the AC lighting system; and

a plurality of LED groups comprising a first LED group and a second LED group; and

an AC driver comprising a first current sink and a second current sink and connected between the AC power source and the plurality of LED groups,

wherein the first LED group comprises a first set of LED elements including at least one LED element from each of the plurality of LED packages; and

wherein the second LED group comprises a second set of LED elements including at least one LED element other that the first set of LED elements from each of the plurality of LED packages.

2. The AC lighting system of claim 1, wherein the first current sink controls a first LED current flowing through the first LED group, and wherein the second current sink controls a second LED current flowing through the second LED group.

3. The AC lighting system of claim 2, wherein the first current sink is connected to the first LED group, and wherein the second LED group is serially connected to the first LED group via the first current sink.

4. The AC lighting system of claim 2, wherein the plurality of LED groups further comprise a third LED group, and wherein the third LED group comprises a third set of LED elements including at least one LED element other that the first set of LED elements and the second set of LED elements from each of the plurality of LED packages.

5. The AC lighting system of claim 4, wherein the AC driver further comprising a third current sink, and wherein the third current sink controls a third LED current flowing through the third LED group.

6. The AC lighting system of claim 5, wherein the first LED group, the second LED group, and the third LED group are serially connected via the first current sink, the second current sink and the third current sink.

7. The AC lighting system of claim 1, wherein the first set of LED elements of the first LED group includes a first row of LED elements from a first group of LED packages, and a second row of LED elements from a second group of LED packages.

8. An AC lighting driver comprising:

a voltage input for receiving AC power from an AC power source; and

a plurality of current sinks comprising a first current sink and a second current sink;

wherein the first current sink is connected to and drives a first LED group of a plurality of LED groups,

wherein the second current sink is connected to and drives a second LED group of the plurality of LED groups,

wherein the first LED group comprises a first set of LED elements including at least one LED element from each of the plurality of LED packages, and

wherein the second LED group comprises a second set of LED elements including at least one LED element other that the first set of LED elements from each of the plurality of LED packages.

9. The AC lighting driver of claim 8, wherein the first current sink controls a first LED current flowing through the first LED group, and wherein the second current sink controls a second LED current flowing through the second LED group.

10. The AC lighting driver of claim 9, wherein the first current sink is connected to the first LED group and, and wherein the second LED group is serially connected to the first LED group via the first current sink.

11. The AC lighting driver of claim 8, wherein the plurality of LED groups further comprising a third LED group, and wherein the third LED group comprising a third set of LED elements including at least one LED element other that the first set of LED elements and the second set of LED elements from each of the plurality of LED packages.

12. The AC lighting driver of claim 11, wherein the AC driver further comprising a third current sink, and wherein the third current sink controls a third LED current flowing through the third LED group.

13. The AC lighting driver of claim 12, wherein the first LED group, the second LED group, and the third LED group are serially connected via the first current sink, the second current sink and the third current sink.

14. The AC lighting driver of claim 8, wherein the first set of LED elements of the first LED group includes a first row of LED elements from a first group of LED packages, and a second row of LED elements from a second group of LED packages.

15. A method for driving a plurality of LED groups comprising:

providing an LED driver that is configured to control an LED current flowing through a corresponding LED group of the plurality of LED groups using a plurality of current sinks;

grouping a first LED group comprising a first set of LED elements, wherein the first set of LED elements includes at least one LED element from each of the plurality of LED packages; and

grouping a second LED group comprising a second set of LED elements, wherein the second set of LED elements includes at least one LED element other that the first set of LED elements from each of the plurality of LED packages.

16. The method of claim 15 further comprising:

controlling a first LED current flowing through the first LED group using a first current sink of the plurality of current sinks, and

controlling a second LED current flowing through the second LED group using a second current sink of the plurality of current sinks.

17. The method of claim 16, wherein the first current sink is connected to the first LED group, and wherein the second LED group is serially connected to the first LED group via the first current sink.

18. The method of claim 16, further comprising grouping a third LED group comprising a third set of LED elements, wherein the third set of LED elements includes at least one LED element other that the first set of LED elements and the second set of LED elements from each of the plurality of LED packages.

19. The method of claim 18, further comprising controlling a third LED current flowing through the third LED group using a third current sink of the plurality of current sinks.

20. The method of claim 19, further comprising serially connecting the first LED group, the second LED group, and the third LED group.

21. The method of claim 15, wherein the first set of LED elements of the first LED group includes a first row of LED elements from a first group of LED packages, and a second row of LED elements from a second group of LED packages.