Ad Semiconductor Co., Ltd.

Averd Co., Ltd.

Min Sung Yang

Si Youl Noh

Jae Hong Joo

Sang Bo Cheong

Seong Hyun Nam

Sang Chuel Lee

Kwang Deok Park

The present invention relates to a resistive touchscreen for recognizing touch coordinates through a capacitor charging time constant, and more specifically, the invention comprises: an equal resistance line operating means for obtaining the same resistance line according to an (R+R) value and the same resistance line according to an (R+R) value by using the charge time constant after a charge time constant measuring means measures charge time constants of capacitors CL and CR; and a coordinate calculating means for obtaining intersecting points of the resistance lines, thereby perceiving the intersecting points as touch positions. According to the present invention, a conventional ADC (analog to digital converter) is not used because the touch positions can be perceived through the capacitor charging time constants, whereby the invention is advantageous for IC integration.

Multi-touch recognition resistive touch screen for recognizing multi-touch coordinates through capacitor charging time

Disclosed is a power supply apparatus using a half-bridge type driving circuit, which is intended for the purpose of the compensation of a power factor, the achievement of a low crest factor and the maintenance of a constant output. The power supply apparatus using a half-bridge circuit for rectifying an AC power source and providing the rectified power source to a load includes a line voltage detecting means for detecting a voltage of an input power source provided to the load, an error amplifying means for comparing the voltage detected from the line voltage detecting means with a reference voltage and outputting a voltage corresponding to a difference therebetween, a pulse width modulating means for outputting a pulse having a variable width corresponding to an output level of the error amplifying means, a dead time controlling means for outputting a first pulse corresponding to a high side and a second pulse corresponding to a low side by the pulse output from the pulse width modulating means, wherein the first and second pulses have different pulse widths and different rising and falling time points, and a driving means for driving the power source supplied to the load as a constant current state by the first and second pulses.

Power supply apparatus using half-bridge circuit

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Seoul, South Korea

Min Sung Yang