Abstract: Disclosed is a compensation circuit for a common voltage according to a gate voltage, which compensates the common voltage in accordance with variation in gate high voltage, to obtain an optimal common voltage. The compensation circuit includes a divider to divide a gate high voltage, an adder to add a fed-back common voltage to a voltage output from the divider, and a differential amplifier to differentially amplify a voltage output from the adder, and to output the amplified voltage as a compensated common voltage.

Abstract: A welding portion inspection system includes a sensing head, and first and second electrodes that are disposed a predetermined distance from each other at one side of the sensing head, where front end portions of the first and second electrodes contact both sides of a welding portion to apply current such that a temperature of the welding portion is heated, and an infrared camera is disposed on the sensing head and detects a temperature distribution of the welding portion.

Abstract: Disclosed is a compensation circuit for a common voltage according to a gate voltage, which compensates the common voltage in accordance with variation in gate high voltage, to obtain an optimal common voltage. The compensation circuit includes a divider to divide a gate high voltage, an adder to add a fed-back common voltage to a voltage output from the divider, and a differential amplifier to differentially amplify a voltage output from the adder, and to output the amplified voltage as a compensated common voltage.

Abstract: An apparatus and a method recognizes stamped characters, detects stamped depths of characters using the same, and/or accurately recognizes characters even when an image distortion occurs at stamped portion due to different stamped depths of characters.

Abstract: A method of driving a lamp of a liquid crystal display device includes generating a control signal; generating a first drive signal using the control signal; generating a second drive signal by shifting a voltage level of the first drive signal; selectively outputting one of a high potential supply voltage and a low potential supply voltage in response to the second drive signal; transforming the selectively outputted voltage; and supplying the transformed voltage to a lamp.

Abstract: A method of driving a lamp of a liquid crystal display device includes generating a control signal; generating a first drive signal using the control signal; generating a second drive signal by shifting a voltage level of the first drive signal; selectively outputting one of a high potential supply voltage and a low potential supply voltage in response to the second drive signal; transforming the selectively outputted voltage; and supplying the transformed voltage to a lamp.

Abstract: A method of driving a lamp of a liquid crystal display device includes generating a control signal; generating a first drive signal using the control signal; generating a second drive signal by shifting a voltage level of the first drive signal; selectively outputting one of a high potential supply voltage and a low potential supply voltage in response to the second drive signal; transforming the selectively outputted voltage; and supplying the transformed voltage to a lamp.

Abstract: A lamp driving apparatus of a liquid crystal display includes a plurality of lamps arranged with a predetermined distance between adjacent lamps; a comparator to compare output voltages of lamps that are separated by more than the lamp distance; and a power interceptor to cut off the power supply of a lamp where mis-discharge is generated, in accordance with a comparison result of the comparator. A lamp driving method of a liquid crystal display which includes: comparing a designated reference voltage with lamp output voltages, and intercepting the power supply of the lamp of which the output voltage is different from the reference voltage to stop mis-discharge between lamps.