Logah Technology Corp.

Yun-Ching Wu

Cheng-Chia Hsu

Teng-Kang Chang

Yu-Cheng Pan

A lamp driving structure for backlight module includes a backlight module implemented for disposing a first circuit board and a second circuit board thereon, the first circuit board couples with the second circuit board through a transmission line; the structure further includes at least a square wave controller, two square wave switches, a mutually coupled transformer, a plurality of driving transformers and a plurality of connectors disposed selectively on the first circuit board and the second circuit board, thereby reducing the number of driving transformers and connectors and the area of circuit boards to further reduce the manufacturing cost of the lamp driving device.

Lamp driving structure for backlight module

The locked phase active power current control circuit is composed of a DC source, an electronic switch, a driving transformer, a phase detecting unit, a current intercepting unit and a square wave controller. A DC signal provided by the DC source is converted into a square wave signal by the electronic switch for the driving transformer to operate a load. The electronic switch outputs the square wave signal to the phase detecting unit whereat a phase signal of the square wave is detected and the detected signal is transmitted to the current intercepting unit whereat the detected signal is compared with the current intercepted at the electronic switch, the driving transformer, or the load, and the comparison result is fed back to the square wave controller so as to set the operation frequency of the electronic switch. The essential principle of the present invention is based on the fact that the square wave is in phase with the first harmonic wave.

Locked phase active power current control circuit

A two-end driven lamp controlling device includes a direct-current (DC) power supply, square wave switches, a square wave controller, a plurality of lamps, a plurality of starting transformers and a plurality of lamps commonly connective transformers, wherein the plurality of starting transformers or the plurality of lamps commonly connective transformers are disposed besides the plurality of lamps and the square wave switches are connected to the sides of the plurality of starting transformers or the plurality of lamps commonly connective transformers and to the DC power supply and can receive signals from the square wave controller. The present invention utilizes a circuitry design of a plurality of lamps, a plurality of starting transformers and a plurality of lamps commonly connective transformers so as to make the brightness of the plurality of lamps effectively homogenized and balanced and, moreover, to solve the problem of high cost for conventional devices, which use too many components for maintaining the brightness of the lamps.

Two-end driven lamp controlling device

A control device for multiple lamp currents of a liquid crystal display (LCD) backlight source, comprising an electronic power switch, a transformer, an inverter and an integrated circuit (IC) feedback control module. The transformer has a primary side connected to the electronic power switch and a secondary side having two ends each connected to an end of a set of lamp composed of two lamps. The inverter has three sets of coil connected to the other end of the two sets of lamp. The IC feedback control module is connected between the inverter and the electronic power switch and through which currents flown through the two sets of lamp may be balanced. Meanwhile, the current flown through the inverter is feedback to the IC feedback control module by which a control signal is outputted to the electronic power switch by determining and processing the feedback current, thereby controlling an output signal from the electronic power switch. Therefore, luminance of the multiple lamps in the LCD backlight source may be controlled and maintained.

Control device for multiple lamp currents of liquid crystal display backlight source

A lamp current balancing device comprises an electronic power switch, a transformer, a current transformer and a pulse width modulation (PWM) IC; the transformer having a primary side connected to the electronic power switch and both ends of a secondary side connected to one end of each one of two lamps respectively, with another end of each one of the two lamps connecting to one end of a primary side of the current transformer respectively, the PWM IC being coupled between a secondary side of the current transformer and the electronic power switch; since the two lamps being cascaded in series with a same current flowing through them, thus providing current balancing capability, furthermore, the current transformer being used to detect an operating current of the lamps and to feed back the operating current to the PWM IC, the PWM IC receiving and processing the operating current to obtain a control signal, then outputting the control signal to the electronic power switch to control a pulse width outputted by the electronic power switch, thereby controlling and maintaining a uniform brightness of the lamps.

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Hsinchu, Taiwan

Yun-Ching Wu