Patent ID: 7764028

Claim:
An LED drive circuit, comprising: a switch circuit having a secondary side connected in series between an LED unit and an alternating-current power source that supplies power to the LED unit to drive the LED unit, the switch circuit controlling an electrical connection between the alternating-current power source and the LED unit; and a driver circuit controlling timing with which the secondary side of the switch circuit is brought into/out of conduction by feeding a control signal to a primary side of the switch circuit every half wave of alternating-current power from the alternating-current power source, wherein the LED unit is composed of a first LED group in which a plurality of first LEDs are connected in series in a same forward direction and a second LED group in which a plurality of second LEDs are connected in series in a forward direction that is opposite to the forward direction of the first LEDs, the first LED group and the second LED group being connected in parallel in such a way as to point in different directions, wherein the driver circuit separately controls durations of light emission of the first and second LED groups by controlling the timing with which the secondary side of the switch circuit is brought into/out of conduction.