Abstract: An LED driving circuit having an efficiency improvement function and connected to an alternating current (AC) power supply, includes: a rectifier circuit that rectifies the AC power supply; a control circuit connected to an output of the rectifier circuit; an LED load and a constant-current circuit that are connected to an output of the control circuit in series; a capacitor that is connected in parallel to the LED load and the constant-current circuit that are connected in series to each other, the capacitor smoothing the output of the rectifier circuit; and a detection circuit that detects whether the rectified voltage exceeds a predetermined particular voltage value that is equal to or greater than the sum of a voltage applied to the LED load when the LED load is turned on and a voltage applied to the constant-current circuit at a time when the LED load starts being turned on.

Abstract: Disclosed herein is a lighting apparatus using white-light Light-Emitting Diodes (LEDs). The lighting apparatus includes white-light LEDs, first LEDs, second LEDs, a substrate, a driving unit, and wires. The white-light LEDs emit light having a first peak value in a wavelength range of about 440 to 460 nm and a second peak value in a wavelength range of about 520 to 600 nm as a main light source. The first LEDs emit light having a third peak value in a wavelength range of about 610 to 625 nm as an auxiliary light source. The second LEDs emit light having a fourth peak value in a wavelength range of about 492 to 500 nm as an auxiliary light source. The substrate allows the LEDs to be disposed thereon. The driving unit drives the LEDs. The wires connect the substrate to the driving unit.

Abstract: Disclosed herein is a power supply device capable of correcting power factor. The power supply device includes a rectification circuit, a first constant current circuit, a capacitor, and a second constant current circuit. The rectification circuit rectifies input Alternating Current (AC) voltage. The first constant current circuit is connected in series to a load. The capacitor is connected in parallel to the first constant current circuit and the load that are connected in series to each other. The second constant current circuit is disposed between the output of the rectification circuit and the capacitor.