LED LIGHTING APPARATUS

• US 20130320867A1
• Filed: 05/31/2013
• Published: 12/05/2013
• Est. Priority Date: 05/31/2012
• Status: Active Grant

• Current Assignee: Silicon Works Co., Ltd.
• Original Assignee: Silicon Works Co., Ltd.
• Inventors: KIM, Yong Guen, LEE, Sang Young
• Granted Patent: US 9,237,618 B2
• Time in Patent Office: Days
• US Class Current: 315/186
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H05B 45/345 Current stabilisation; Maintaining constant current
• CPC Class Codes: H05B 45/355 Power factor correction [PFC]; Reactive power compensation
• CPC Class Codes: H05B 45/395 Linear regulators
• CPC Class Codes: H05B 45/40 Details of LED load circuits
• CPC Class Codes: H05B 45/44 with an active control inside an LED matrix
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines
• CPC Class Codes: H05B 45/48 having LEDs organised in strings and incorporating parallel shunting devices

Abstract

Disclosed is an LED lighting apparatus capable of improving a power factor and temperature characteristics. The LED lighting apparatus according to a preferred embodiment of the present invention includes a light source having a plurality of LED channels and performs a current regulating operation to allow a light source to emit light. The light source uses a current path provided by current regulating to emit light.

Claims

1. An LED lighting apparatus comprising:

a power supply unit configured to convert an AC voltage and provide a rectified voltage;

a light source configured to include N LED channels (N is a natural number) including at least one LED; and

a current control circuit configured to divide a varying width of the rectified voltage into N periods in response to a light-emitting voltages for each LED channel, detect a current flowing in the LED channels corresponding to the period, and control the light source to emit light by using a current detection voltage corresponding to the detected current,

wherein the N LED channels are arranged within a predetermined region on a substrate and have a heat radiating priority determined depending on a heat value by light output and a position of the LED channels on the substrate is determined depending on the heat radiating priority.

2. The LED lighting apparatus of claim 1, wherein the current control circuit comprises:

N switching circuits each configured to correspond to each LED channel and be connected to each LED channel in parallel to form current paths;

a current detection resistor configured to be commonly connected between the N switching circuits and a ground to provide the current detection voltage; and

a reference voltage generation circuit configured to provided a plurality of reference voltages having different levels corresponding to each switching circuit, and

the N switching circuits compare the reference voltage corresponding thereto with the current detection voltage to selectively provide the current paths.

3. The LED lighting apparatus of claim 2, wherein the reference voltage generation circuit provides the reference voltage to the switching circuit connected to the LED channel having a high light-emitting voltage and provides the reference voltage to the switching circuit connected to the LED channel having a low light-emitting voltage.

4. The LED lighting apparatus of claim 2, wherein the N switching circuits gradually shift a position of the current path to the LED channel having the high light-emitting voltage when the rectified voltage rises and gradually shift a position of the current path to the LED channel having the low light-emitting voltage when the rectified voltage falls.

5. The LED lighting apparatus of claim 2, wherein the N switching circuits comprise:

a comparator configured to compare the reference voltage with the current detection voltage to output the compared results; and

a switching element configured to turn on/off the current path between the LED channel connected to thereto and the current detection resistor in response to an output of the comparator.

6. The LED lighting apparatus of claim 1, wherein the current control circuit comprises:

N switching circuits each configured to correspond to each LED channel and be connected to each LED channel in parallel to form current paths;

N current detection resistors configured to be independently connected between the N switching circuits and a ground to provide the current detection voltage; and

a reference voltage generation circuit configured to provide a plurality of reference voltages corresponding to each switching circuit, and

the N switching circuits compare the reference voltage corresponding thereto with the current detection voltage to selectively provide the current paths.

7. The LED lighting apparatus of claim 6, wherein the N current detection resistors have uniform resistance values so as to satisfy turn on conditions for each of the N switching circuits.

8. The LED lighting apparatus of claim 6, wherein the reference voltage generation circuit provides the reference voltage to the switching circuit connected to the LED channel having a high light-emitting voltage and provides the reference voltage to the switching circuit connected to the LED channel having a low light-emitting voltage.

9. The LED lighting apparatus of claim 1, wherein the current control circuit comprises:

N switching circuits configured to correspond to each LED channel and be connected to each LED channel in parallel to form current paths;

N current detection resistors configured to independently connect between the N switching circuits and a ground to provide the current detection voltage;

a reference voltage generation circuit configured to commonly provide a reference voltage having a fixed level to the N switching circuits, and

the N switching circuits compare the reference voltage with the current detection voltage corresponding thereto to selectively provide the current paths.

10. The LED lighting apparatus of claim 9, wherein the N current detection resistors have low resistance values as being far away from a position at which the rectified voltage is applied.

11. The LED lighting apparatus of claim 1, wherein the LED channel having the high heat radiating priority is arranged at an outer side and the LED channel having the low heat radiating priority is arranged in an inner side.

12. The LED lighting apparatus of claim 1, wherein the light source comprises first to third LED channels connected to each other in series and the second LED channel is disposed between the first LED channel and the third LED channel.

13. The LED lighting apparatus of claim 1, wherein the LED channels are disposed in a helical form within the region.

14. The LED lighting apparatus of claim 11, wherein the LED channels are disposed so that spacing between the LEDs included in the LED channel located at the outer side is gradually wider than spacing between the LED channels included in the LED channel located in the inner side.

15. A LED lighting apparatus comprising:

a light source configured to include N LED channels (N is a natural number) including at least one LED configured in series, the N LED channels being arranged in each region on a substrate depending to a heat radiating priority and the heat radiating priority being determined depending on a heat value by light output; and

a current regulating circuit configured to provide current paths for the N LED channels at different positions in response to a variation of a rectified voltage provided to the light source,

wherein the current regulating circuit comprises;

N switching circuits configured to be connected to each output terminal of the N LED channels in parallel to form the current paths;

N current detection resistors configured to be independently connected to the N switching circuits and a ground to provide a current detection voltage; and

a reference voltage generation circuit configured to generate and provide reference voltages having different levels for each of the N switching circuits, and

the N switching circuits compare their own reference voltage with the current detection voltage corresponding thereto to selectively provide the current paths.

16. An LED lighting apparatus comprising:

a light source configured to include N LED channels (N is a natural number) including at least one LED configured in series, the N LED channels being arranged in each region on a substrate depending to a heat radiating priority and the heat radiating priority being determined depending on a heat value by light output; and

a current regulating circuit configured to provide current paths for the N LED channels at different positions in response to a variation of a rectified voltage provided to the light source,

wherein the current regulating circuit comprises;

N switching circuits configured to be connected to each output terminal of the N LED channels in parallel to form the current paths;

N current detection resistors configured to be independently connected to the N switching circuits and a ground to provide a current detection voltage; and

a reference voltage generation circuit configured to commonly provide a reference voltage having a fixed level to each switching circuit, and

the N switching circuits compare the reference voltage with the current detection voltage corresponding thereto to selectively provide the current paths.