Driver for liquid-filled lens generating high-voltage drive signal

A liquid-filled lens driver for receiving a lens driver control signal from an image signal processor and driving a liquid-filled lens, comprising:

• an input/output interface unit exchanging the lens driver control signal and status information of the liquid-filled lens with the image signal processor according to a certain signal transmission protocol;
• a system clock generation unit for generating a system clock;
• a high voltage generation unit for generating high voltage, which can drive the liquid-filled lens, using low voltage of a battery of a mobile information terminal;
• a voltage generation unit for providing reference voltage and bias voltage for operating the liquid-filled lens driver;
• a drive signal generation unit for generating a final drive signal for the liquid-filled lens by generating an output waveform for driving the liquid-filled lens and boosting the output waveform to a high voltage level generated by the high voltage generation unit;
• and
• a control unit for controlling the function units so that they can drive the liquid-filled lens.

A high voltage generation circuit for generating high voltage to drive a liquid-filled lens, comprising:

• a converter module for DC-converting voltage of a battery of the mobile information terminal into high voltage for driving the liquid-filled lens;
• a voltage conversion clock generation module for generating a voltage conversion clock that is used for the DC voltage conversion by the converter module;
• a voltage conversion arresting module for stopping voltage conversion by stopping operation of the converter module when the voltage conversion is performed such that the high voltage generated by the converter module exceeds voltage for driving the liquid-filled lens (reference voltage);
• a voltage division module for generating divided voltage lower than the high voltage by dividing the high voltage, which has been obtained through the conversion by the converter module, at a certain ratio;
• and
• a voltage comparison module for comparing curvature reference voltage required for operation of the liquid-filled lens with the divided voltage generated by the voltage division module, and providing an arresting signal to the voltage conversion arresting module when the divided voltage exceeds the curvature reference voltage;
• wherein the voltage conversion clock generation module generates a plurality of clocks having various frequencies so that the converter module can selectively use a voltage conversion clock;
• and
• wherein the converter module variably selects and uses the plurality of clocks, which are generated from the voltage conversion clocks, according to characteristics of electric elements (inductor, capacitor, diode) of the converter module.

A drive signal generation circuit for generating an output waveform to drive a liquid-filled lens, comprising:

• a drive signal clock generation module for generating a drive clock in a waveform period of a signal for driving the liquid-filled lens;
• a low voltage differential signal generation module for generating two low voltage differential signals having a voltage level of a battery of the mobile information terminal based on the drive clock;
• and
• a high voltage differential signal generation module for generating plus and minus differential drive signals, that is, the final drive signal for the liquid-filled lens, by increasing a voltage amplitude of the low voltage differential signal to a level of the high voltage generated by the high voltage generation unit.