IP Library Granted Patent US 7,898,515
Granted Patent B2
US 7,898,515 · App. 11/299,629 · Granted Mar 1, 2011

Liquid crystal display

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 7,898,515
App. No.
11/299,629
Granted
Mar 1, 2011
Kind
B2
Abstract

A liquid crystal display device includes a plurality of pixel electrodes to which a data voltage is supplied, a plurality of common electrodes arranged to form electric fields with the pixel electrodes, a plurality of common wire lines commonly connected to the common electrodes in each horizontal line, a plurality of common voltage drive circuits to supply a common voltage to each of the corresponding common wire lines, and a controller for generating clock signals to control the common voltage drive circuits to invert an electric potential of the common voltage to be output from each of the common voltage drive circuits for each frame period.

Claims (22)

1. A liquid crystal display device having a thin film transistor substrate, comprising:

a plurality of pixel electrodes to which a data voltage is supplied;

a plurality of common electrodes arranged to form horizontal electric fields with the pixel electrodes;

a plurality of common wire lines commonly connected to the common electrodes in each horizontal line;

a plurality of common voltage drive circuits to supply a first and second common voltage to each of the corresponding common wire lines in response to the clock signals for each frame period; and

a controller to generate clock signals which control the common voltage drive circuits that invert an electric potential of the common voltage to be output from each of the common voltage drive circuits for each frame period,

wherein the pixel electrodes, the common electrodes, the common wire lines, and the common voltage drive circuits are formed on the thin film transistor substrate,

wherein each of the common voltage drive circuits includes a first transistor and a second transistor commonly connected to the common wire line,

wherein a gate electrode of the first transistor is connected to a first clock signal line, a drain electrode of the first transistor is connected to a first common voltage line, and a source electrode of the first transistor is connected to the common wire line, and

a gate electrode of the second transistor is connected to a second clock signal line, a source electrode of the second transistor is connected to a second common voltage line, and a drain electrode of the second transistor is connected to the common wire line,

wherein the plurality of common voltage drive circuits to supply a first and second common voltage to each of the corresponding common wire lines in response to the clock signals for each frame period comprising a first common drive circuit of the plurality of common voltage drive circuits is connected to a first common wire line of the plurality of common wire lines supplies the first common voltage of high potential to the first common wire line of the first horizontal line during an odd-numbered frame period and a negative analog data voltage is supplied by the data drive circuit to the pixel electrodes of a liquid crystal cells included in the first horizontal line and, subsequently the first common drive circuit is supplied the second common voltage of low potential to the first common wire line during an even-numbered frame period and a positive analog data voltage is supplied to the pixel electrodes of the liquid crystal cells included in the first horizontal line,

a second common drive circuit of the plurality of common voltage drive circuits is connected to a second common wire line of the plurality of common wire lines supplies the second common voltage of low potential to the second common wire line of the second horizontal line during the odd-numbered frame period and the positive analog data voltage is supplied by the data drive circuit to the pixel electrodes of the liquid crystal cells included in the second horizontal line and, subsequently the second common drive circuit is supplies the second common voltage of high potential to the second common wire line during the even-numbered frame period and the negative analog data voltage is supplied to the pixel electrodes of the liquid crystal cells included in the second horizontal line.

2. The liquid crystal display device according to claim 1 , further including a level shifter to shift a voltage level of a clock signal generated from the controller and to supply the shifted clock signal to the common voltage drive circuits.

3. The liquid crystal display device according to claim 1 , further including:

a plurality of data lines;

a plurality of gate lines that cross the data lines;

a plurality of thin film transistors to supply a data voltage from the data line to the pixel electrodes in response to a scan voltage on the gate lines;

a data drive circuit to convert a digital image data into an analog data voltage to be supplied to the data lines; and

a gate drive circuit to sequentially supply the scan voltage to the gate lines,

wherein the controller controls the data drive circuit and the gate drive circuit.

4. The liquid crystal display device according to claim 3 , wherein the data drive circuit supplies first and second common voltages to the common voltage drive circuits.

5. The liquid crystal display device according to claim 4 , wherein the data drive circuit generates analog data voltages of the same polarity corresponding to liquid crystal cells that are horizontally adjacent, and analog data voltages of opposite polarities corresponding to liquid crystal cells that are vertically adjacent.

Assignments (2)
CHANGE OF NAME Recorded Jun 19, 2008
From: LG.PHILIPS LCD CO., LTD.
To: LG DISPLAY CO., LTD.
Reel/Frame 021147/0009 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 13, 2005
From: MOON, SU HWAN; KIM, DO HEON; CHAE, JI EUN
To: LG.PHILIPS LCD CO., LTD.
Reel/Frame 017340/0850 →