Lighting apparatus

Patent metadata

Field	Value
Publication number	US-9538591-B2
Application number	US-201514807023-A
Country	US
Kind code	B2
Filing date	Jul 23, 2015
Priority date	Jul 29, 2014
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

Provided is a lighting apparatus using an LED as a lighting source. The lighting apparatus may distribute a current corresponding to a rectified voltage to a lighting unit and a secondary current circuit, perform primary light emission at low luminance, and reduce an optical deviation between LED groups through secondary light emission. Thus, the lighting apparatus can reduce an optical deviation corresponding to dimming and one cycle of rectified voltage.

First claim

What is claimed is:

1. A lighting apparatus comprising:
a lighting unit comprising a plurality of LED groups each having one or more LEDs and configured to emit light in response to a rectified voltage, the plurality of LED groups including a first LED group which first emits light in response to the rectified voltage and provides a path for a first current;
a driving circuit configured to provide one or more current paths to the plurality of LED groups, the one or more current paths being changed in response to a change of the rectified voltage; and
one or more secondary current sources coupled to one or more of the plurality of LED groups excluding the first LED group, and each configured to provide a second current which differs according to the change of the rectified voltage,
wherein the rectified voltage is distributed and supplied to the lighting unit and the secondary current source, and
wherein the LED group coupled to the secondary current source performs primary light emission using the first current and the second current in response to the rectified voltage having a level equal to or more than the level which the first current provided through the first LED group reaches, and performs secondary light emission using the second current in response to the rectified voltage having a lower level than the level for the primary light emission.

2. The lighting apparatus of claim 1 , wherein the secondary current source provides the second current at the same time as the first LED group emits light or after the first LED group emits light.

3. The lighting apparatus of claim 1 , wherein the driving circuit performs current regulation on the current path.

4. The lighting apparatus of claim 1 , wherein the secondary current source provides a constant amount of second current while the level of the rectified voltage is maintained at more than the level at which the first current reaches the LED group coupled thereto, and provides the second current which increases or decreases in response to the change of the rectified voltage when the level of the rectified voltage is lower than the level at which the first current reaches the LED group coupled thereto.

5. The lighting apparatus of claim 4 , wherein the secondary current source provides the constant amount of second current corresponding to the level of the rectified voltage, at which the first current reaches the LED group coupled thereto, when the level of the rectified voltage is maintained at more than the level at which the first current reaches the LED group coupled thereto.

6. The lighting apparatus of claim 1 , wherein the secondary current source provides a constant amount of second current while the level of the rectified voltage is maintained at more than the level at which the first current reaches the LED group coupled thereto.

7. The lighting apparatus of claim 1 , wherein each of the secondary current sources is coupled to two or more LED groups, and provides the second current while the level of the rectified voltage is maintained at more than the level at which the first current reaches the LED group coupled thereto.

8. The lighting apparatus of claim 1 , wherein the secondary current source provides the second current in response to a preset voltage.

9. The lighting apparatus of claim 8 , wherein the secondary current source provides the second current using a voltage applied to the first LED group.

10. A lighting apparatus comprising:
a lighting unit comprising a plurality of LED groups each having one or more LEDs, and configured to emit light in response to a rectified voltage, the plurality of LED groups including a first LED group which first emits light in response to the rectified voltage and provides a path for a first current;
a driving circuit configured to provide one or more current paths to the plurality of LED groups, the one or more current paths being changed in response to a change of the rectified voltage; and
one or more secondary current sources coupled to one or more of the plurality of LED groups excluding the first LED group, and each configured to provide a constant amount of second current in response to the rectified voltage having a level at which the first current provided through the first LED group reaches the LED group coupled thereto, and provide the second current which increases or decreases in response to a change of the rectified voltage having a lower level than the level at which the first current reaches the LED group coupled thereto,
wherein the rectified voltage is distributed and supplied to the lighting unit and the secondary current source, and
wherein the LED group coupled to the secondary current source performs primary light emission using the first current and the second current in response to the level of the rectified voltage equal to or more than the level which the first current reaches, and performs secondary light emission using the second current in response to the rectified voltage lower than the level which the first current reaches.

11. The lighting apparatus of claim 10 , wherein the secondary current source provides the second current at the same time as the first LED group emits light or after the first LED group emits light.

12. The lighting apparatus of claim 10 , wherein the driving circuit performs current regulation on the current path.

13. A lighting apparatus comprising:
a lighting unit comprising a plurality of LED groups each having one or more LEDs, and configured to emit light in response to a rectified voltage, the plurality of LED groups including a first LED group which first emits light in response to the rectified voltage and provides a path for a first current;
a driving circuit configured to provide one or more current paths to the plurality of LED groups, the one or more current paths being changed in response to a change of the rectified voltage; and
one or more secondary current sources coupled to one or more of the plurality of LED groups excluding the first LED group, and each configured to provide a constant amount of second current,
wherein the rectified voltage is distributed and supplied to the lighting unit and the secondary current source, and
wherein the LED group coupled to the secondary current source performs primary light emission using the first current and the second current in response to the rectified voltage having a level equal to or more than the level which the first current provided through the first LED group reaches, and performs secondary light emission using the second current in response to the rectified voltage having a lower level than the level which the first current reaches.

14. The lighting apparatus of claim 13 , wherein the secondary current source provides the second current at the same time as the first LED group emits light or after the first LED group emits light.

15. The lighting apparatus of claim 13 , wherein the driving circuit performs current regulation on the current path.

16. The lighting apparatus of claim 13 , wherein the secondary current source provides the second current using a voltage applied to the first LED group.

Assignees

• Silicon Works Co Ltd

Inventors

• Kim Yong Geun

Classifications

• H05B45/48

  having LEDs organised in strings and incorporating parallel shunting devices · CPC title

• H05B45/395 Primary

  Linear regulators · CPC title

• H05B47/10 Primary

  Controlling the light source · CPC title

• H05B45/46

  having LEDs disposed in parallel lines · CPC title

• H05B45/00

  Circuit arrangements for operating light-emitting diodes [LED] · CPC title