Samsung Electro-Mechanics Co., Ltd.

University of Seoul Industry Cooperation Foundation

Yeun Joong Lee

Sang Hyun Cha

Jae Shin Lee

Deuk Hee Park

Change Seok Lee

Chang Seok Lee

Gyu Hyeong Cho

Joong Ho Choi

Jin Yong Jeon

Jun Hyeok Yang

Hyun Sik Kim

There are provided an LED driving apparatus and an LED driving method thereof. The LED driving apparatus includes: a light emitting unit including one or more LEDs, a rectifying unit rectifying an input signal to generate a first signal; a signal conversion unit inverting a waveform of a first signal to generate a second signal; and an operation unit arithmetically operating the first and second signals. A plurality of AC signals each having a different waveform are arithmetically operated to generate a signal having a small amount of a ripple component, and an LED is driven by the signal, thus preventing a lifespan of the LED from being shortened by omitting a smoothing electrolytic capacitor, one of main causes shortening the lifespan of an LED driving circuit.

LED driving apparatus and method

There is provided an LED circuit including a light emitting unit including a plurality of light emitting diodes; and a switching unit switching to apply only positive voltage of an AC power supply to an anode of the light emitting unit. Through this, the LED circuit can reduce complexity of a driving circuit. Further, lifespan and efficiency of the LED circuit may be improved since an electrolytic capacitor and a bridge circuit are not used. Further, any one light emitting diode may be prevented from determining the lifespan of all of the light emitting diodes since all of the light emitting diodes are driven at all times, thereby improving the lifespan of the light emitting diode.

LED circuit

A fixture-compatible, dimmable illumination driving apparatus including: a rectifying unit rectifying a phase-controlled waveform of an alternating current (AC) power; a comparing unit comparing an output waveform of the rectifying unit with a first voltage according to a preset reference clock; a reference voltage generating unit generating a reference voltage corresponding to the number of high signals higher than the first voltage among outputs of the comparing unit during one cycle of the output waveform; and a pulse width modulation (PWM) signal generating unit generating a PWM signal from the reference voltage and a feedback voltage.

Illumination driving apparatus

There is provided an LED circuit. The LED circuit may include 2N+2 light emitting units connected between a 2K&#x2212;1-th node and a 2K-th node among 4N+4 (N is a natural number) nodes including a first node supplied with input voltage (K is all natural numbers equal to or smaller than 2N+2); 2N+2 switches connected between a 2K-th node and a ground (K is all natural numbers equal to or smaller than 2N+2); 2N+1 switches connected between a 2L&#x2212;1-th node and a 2L+1-th node and 2N+1 switches connected between a 2L-th node and a 2L+1-th node (L is all natural numbers equal to or smaller than 2N+1); and N switches connected between the first node and a 4M+1-th node (M is all natural numbers equal to or smaller than N).

There is provided an organic light emitting diode driver capable of compensating for pixel deterioration in real time during the driving of pixels by selectively compensating pixels, requiring compensation, for the deterioration thereof, and precisely setting calibration data by removing an IR drop across a transistor, employed as a switch in the pixels, by calculating a difference between at least two representative values of different gray scale ranges among predetermined gray scale ranges.

Growing community of inventors

Seoul, South Korea

Yeun Joong Lee