LED LIGHTING DEVICE AND ILLUMINATION APPARATUS INCLUDING SAME

• US 20120153863A1
• Filed: 12/13/2011
• Published: 06/21/2012
• Est. Priority Date: 12/20/2010
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Inventors: HAMAMOTO, Katunobu, YAMAMOTO, Masafumi, UEDA, Keisuke, TAKIKITA, Hisaya
• Granted Patent: US 8,836,239 B2
• Time in Patent Office: Days
• US Class Current: 315/291
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]

Abstract

An LED lighting device includes a converter for converting a power source voltage into a DC voltage and outputting it to an LED unit; and a controller for controlling an output of the converter. The converter has a chopper circuit including a series circuit of an inductance element and a capacitor; a switching element connected to the inductance element in series and turned on/off by the controller; and a diode as discharging path of the inductance element during an OFF state of the switching element. The controller controls an on/off time of the switching element such that a current supplied to the LED unit during a specific time period after a lighting operation is started becomes smaller than a current supplied to the LED unit in a steady state by using a voltage generated in a secondary coil of the inductance coil as an operating voltage thereof.

Claims

1. An LED lighting device comprising:

a power converting unit for converting a power source voltage to a DC voltage and outputting the DC voltage to an LED unit; and

an output control unit for controlling an output of the power converting unit,

wherein the power converting unit has a chopper circuit including a series circuit of an inductance element and a capacitor;

a switching element which is connected to the inductance element in series and turned on and off by the output control unit; and

a diode serving as a discharging path of the inductance element during an OFF state of the switching element, and

the output control unit controls an on and off time of the switching element in such a way that a current supplied to the LED unit during a specific time period after a lighting operation is started becomes smaller than a current supplied to the LED unit in a steady state by using a voltage generated in a secondary coil of the inductance coil as an operating voltage thereof.

2. The device of claim 1, wherein the output control unit uses a positive voltage generated in the secondary coil is used as the operating voltage thereof when charges accumulated in the inductance element are discharged.

3. The device of claim 1, wherein the output control unit controls the operation of the switching element in a critical mode where the switching element is turned on at the time when a current flowing through the inductance element becomes zero, and uses the secondary coil to detect the current flowing through the inductance element.

4. The device of claim 2, wherein the output control unit controls the operation of the switching element in a critical mode where the switching element is turned on at the time when a current flowing through the inductance element becomes zero, and uses the secondary coil to detect the current flowing through the inductance element.

5. An illumination apparatus comprising:

the LED lighting device of claim 1;

lamp sockets to which the LED unit is mechanically electrically connected; and

an apparatus body for holding the LED lighting device and the lamp sockets.

6. An illumination apparatus comprising:

the LED lighting device of claim 2;

lamp sockets to which the LED unit is mechanically electrically connected; and

an apparatus body for holding the LED lighting device and the lamp sockets.

7. An illumination apparatus comprising:

the LED lighting device of claim 3;

lamp sockets to which the LED unit is mechanically electrically connected; and

an apparatus body for holding the LED lighting device and the lamp sockets.

8. An illumination apparatus comprising:

the LED lighting device of claim 4;

lamp sockets to which the LED unit is mechanically electrically connected; and

an apparatus body for holding the LED lighting device and the lamp sockets.