Himax Technologies, Inc.

Yu-Pei Huang

Shwang-Shi Bai

Shen-Yao Liang

Shu-Ming Chang

The present invention is directed to an apparatus that drives a lighting system with multiple lamps. A phase shift mechanism is produced either by a digital method, an analog method, or a mixture of the two methods. In a digital method, phase shifts are generated by digital circuits comprising counters, a divider, an adder, and a comparator. The digital circuits analyze the signal and use the necessary information to form a series of phased driving signals. In an analog method, phase shifts are generated by analog circuits comprising ramp waveform generators, comparators, and at least one shot generator. Also, an apparatus for driving a lighting system with multiple lamps can be realized by mixing the two methods mentioned above.

Control system for multiple fluorescent lamps

The invention is a driving apparatus and circuit for efficiently converting a direct current (DC) signal into an alternating current (AC) signal to drive a fluorescent lamp. A semi class E configuration which utilizes only one transistor is employed in the invention. The invention comprises a power transistor, a transformer wherein a primary winding is used as a load for the power transistor and a secondary winding is used to transfer energy to the load for the driving apparatus, i.e. the CCFL tube, and control means which extracts the frequency and current of the power transistor and corrects the deviation between the frequency of the power transistor and that of the control means.

High efficiency and low cost cold cathode fluorescent lamp driving apparatus for LCD backlight

An inverter has an inductor, a capacitor, a switching device, a driving circuit and a transformer. A first terminal of the capacitor is connected to the inductor, and the switching device is connected between the first terminal of the capacitor and a ground terminal. The driving circuit is connected to the switching device, wherein the driving circuit is arranged to control the switching device to turn on or turn off; and a primary side of the transformer is connected between a second terminal of the capacitor and the ground terminal.

Inverter having single switching device

A lamp driving device has a pulse width modulation circuit, a phase splitter and several switching circuits. The pulse width modulation circuit is arranged to generate a pulse width modulation signal. The phase splitter is coupled to the pulse width modulation circuit and arranged to split the pulse width modulation signal into several phased signals having different phases, wherein pulses of each phased signal are non-overlapping with those of another phased signal. The switching circuits are coupled to the phase splitter and are arranged to respectively receive one of the phased signals, wherein each switching circuit is controlled by the received phased signal.

Lamp driving device and method

A backlight driver circuit has a transformer, a switching circuit and a plurality of switch devices. The switching circuit couples a DC voltage to a primary side of the transformer and alternates polarities thereof so that an AC voltage is generated on a secondary side of the transformer to turn on the backlight blocks. The switch devices are respectively connected between one of the backlight blocks and the transformer, and the AC voltage turns the backlight blocks on when the switch devices are turned on.

Backlight module driver circuit

A method for driving a fluorescent lamp and an inverter circuit for performing the same are used to reduce an amount of electromagnetic interference (EMI) generated by a transformer and an instantaneous loading of a DC voltage source. The inverter circuit comprises a DC square wave voltage source, a bridge DC/AC converter, a transformer, a feedback control unit and a voltage control circuit wherein the voltage control circuit is coupled to the DC voltage source, the bridge DC/AC converter and the feedback control unit. The voltage control circuit is used to convert DC voltage provided by the DC voltage source into a two-level DC square wave, which in turn converts the two-level DC square wave into an AC quasi-sine wave to drive the fluorescent lamp through the bridge DC/AC converter and the transformer. The feedback control unit generates signals to control the voltage control circuit and the bridge DC/AC converter.

Growing community of inventors

Hsinhua, Taiwan

Yu-Pei Huang