SOURCE DRIVING CIRCUIT AND LIQUID CRYSTAL DISPLAY HAVING THE SAME FOR REDUCING CURRENT CONSUMPTION AND RESTRAINING EMI CHARACTERISTIC

• Main Author: PARK, HEE BUM
• Format: Patent
• Language: English; Korean
• Published: 03.03.2005
• Edition: 7
• Subjects: DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

PURPOSE: A source driving circuit and an LCD(Liquid Crystal Display) having the source driving circuit are provided to allow a data output voltage of the source driving circuit not to be inverted during a data blank time to reduce current consumption required for an unnecessary inversion operation and restrain EMI(Electromagnetic Interference) characteristic. CONSTITUTION: A source driving circuit includes a shift register(310) for generating a pulse signal sequentially shifted in response to an external signal, a data register(320) for shifting and storing a data signal in response to the pulse signal, and a digital-analog converter(340) for converting the data signal into an analog gray scale voltage. The source driving circuit further includes a buffer(350) for inverting a data voltage in response to a polarity inversion signal, amplifying the inverted data voltage and applying the amplified data voltage to a data line of an LCD panel, and a switch(360) for enabling the output of the buffer during data valid time, and blocking the output of the buffer and applying a common voltage to the data line of the LCD panel during data blank time.