LED driving apparatus and lighting apparatus including same

• US 9,860,955 B2
• Filed: 03/31/2016
• Issued: 01/02/2018
• Est. Priority Date: 09/02/2015
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Hyun Jung, Lee, Bong Jin
• Primary Examiner(s): Le, Tung X
• Application Number:
  US15/086,952
• Publication Number:
  US 20170064785A1
• Time in Patent Office: 642 Days
• Field of Search: 315186, 315192, 315193, 315294, 315307
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines
• CPC Class Codes: H05B 47/10 Controlling the light source

Abstract

A light emitting diode (LED) driving apparatus includes: a power supply circuit supplying driving power to a first LED group and a second LED group, the first LED group and the second LED group being configured to emit light having different color temperatures; a current controlling circuit controlling a first magnitude of a first current flowing through the first LED group and a second magnitude of a second current flowing through the second LED group; and an LED controller concurrently controlling on/off switching operations of a first LED of the first LED group and a second LED of the second LED group.

Claims

1. A light emitting diode (LED) driving apparatus comprising:

a power supply circuit configured to supply driving power to a first LED group and a second LED group, the first LED group and the second LED group being configured to emit light having different color temperatures;

a current controlling circuit configured to control a first magnitude of a first current flowing through the first LED group and a second magnitude of a second current flowing through the second LED group; and

an LED controller comprising a first common control switch configured to simultaneously change on/off switching operations of a first LED of the first LED group and a second LED of the second LED group and a second common control switch configured to simultaneously change on/off switching operations of a third LED of the first LED group and a fourth LED of the second LED group.

2. The light emitting diode (LED) driving apparatus of claim 1, wherein the current controlling circuit is further configured to receive a color temperature control signal, and to adjust the first magnitude and the second magnitude in accordance with the color temperature control signal.

3. The light emitting diode (LED) driving apparatus of claim 2, wherein the current controlling circuit comprises:

a first resistor electrically connected to the first LED group and a second resistor electrically connected to the second LED group; and

a first transistor electrically connected to the first resistor and the first LED group and a second transistor electrically connected to the second resistor and the first LED group, the first transistor and the second transistor being configured to regulate the first current and the second current flowing through the first resistor and the second resistor in response to a control signal,

wherein the current controlling circuit is further configured to determine a level of the control signal by comparing the first current and the second current to a current corresponding to the color temperature control signal.

4. The light emitting diode (LED) driving apparatus of claim 1, wherein the current controlling circuit comprises:

a current sensing circuit configured to sense the first current and the second current;

a control signal generating circuit configured to generate a first control signal based on the first current sensed by the current sensing circuit and a second control signal based on the second current sensed by the current sensing circuit; and

a current regulating circuit configured to receive the first control signal and the second control signal, and regulate the first current in accordance with the first control signal and the second current in accordance with the second control signal.

5. The light emitting diode (LED) driving apparatus of claim 1, wherein the LED controller is further configured to receive a luminous flux control signal, and adjust a first luminous flux of the first LED group and a second luminous flux of the second LED group based on the luminous flux control signal.

6. The light emitting diode (LED) driving apparatus of claim 1, further comprising a first plurality of diodes electrically connected between the first LED group and the LED controller.

7. The light emitting diode (LED) driving apparatus of claim 1, wherein the LED controller is further configured to sequentially control a first plurality of LEDs included in the first LED group and a second plurality of LEDs included in the second LED group according to a corresponding order of the first plurality of LEDs and the second plurality of LEDs, and simultaneously adjust on/off switching operations of LEDs of the first LED group and the second LED group having an identical order.

8. The light emitting diode (LED) driving apparatus of claim 1, wherein a first quantity of a first plurality of LEDs is identical to a second quantity of a second plurality of LEDs, and the LED controller is further configured to adjust on/off switching operations of the first LED together with on/off switching operation of the second LED group.

9. A lighting apparatus comprising:

a light source comprising a first LED array and a second LED array of a plurality of LED arrays configured to emit light having different color temperatures, each of the plurality of LED arrays comprising a corresponding plurality of LEDs sequentially connected to each other in series;

a power supply circuit configured to rectify power received from an alternating current (AC) power source and supply driving power to the plurality of LED arrays;

a current controlling circuit configured to control a first magnitude of a first current flowing through a first array and a second magnitude of a second current flowing through the second LED array; and

an LED controller comprising a first common control switch configured to simultaneously change on/off switching operations of a first LED of the first LED array and a second LED of the second LED array and a second common control switch configured to simultaneously change on/off switching operations of a third LED of the first LED array and a fourth LED of the second LED array.

10. The lighting apparatus of claim 9, further comprising a substrate on which the plurality of LED arrays are mounted.

11. The lighting apparatus of claim 9, wherein the first LED array is configured to emit light having one of a maximum color temperature, an intermediate color temperature, and a minimum color temperature;

and

the second LED array is configured to emit light having a first color temperature different from a second color temperature of the first LED array.

12. The lighting apparatus of claim 9, wherein the current controlling circuit comprises:

a current sensing circuit configured to sense the first current flowing through the first LED array and the second current flowing through the second LED array;

a control signal generating circuit configured to generate a first control signal based on the first current sensed by the current sensing circuit and a second control signal based on the second current sensed by the current sensing circuit; and

a current regulating circuit configured to receive the first control signal and the second control signal, and regulate the first current in accordance with the first control signal and the second current in accordance with the second control signal.

13. The lighting apparatus of claim 9, wherein the first common control switch is further configured to simultaneously adjust on/off switching operations of the first LED and the second LED, and

wherein the LED controller is further configured to receive a luminous flux control signal and control a first luminous flux of the first LED array and a second luminous flux of the second LED array based on the luminous flux control signal simultaneously.

14. The lighting apparatus of claim 9, further comprising a first plurality of diodes electrically connected between the first LED array and the LED controller.

15. A lighting apparatus comprising:

a first plurality of LEDs, the first plurality of LEDs comprising a first LED and a second LED electrically connected in series to the first LED;

a second plurality of LEDs, the second plurality of LEDs comprising a third LED and a fourth LED electrically connected in series to the third LED;

a plurality of transistors, the plurality of transistors comprising a first transistor and a second transistor,

wherein the first transistor is configured to selectively connect a power source to a first output terminal of the first LED and a third output terminal of the third LED, and the second transistor is configured to selectively connect the power source to a second output terminal of the second LED and a fourth output terminal of the fourth LED.

16. The lighting apparatus of claim 15, further comprising a control circuit configured to generate a luminous flux control signal indicating a total current flowing through the first plurality of LEDs and the second plurality of LEDs.

17. The lighting apparatus of claim 16, wherein the first transistor and the second transistor are configured to turn on and turn off in accordance with the luminous flux control signal.

18. The lighting apparatus of claim 17, wherein the first transistor has a first turn-on voltage and the second transistor has a second turn-on voltage.

19. The lighting apparatus of claim 18, wherein the first turn-on voltage is greater than the second turn-on voltage.