Liquid crystal display thin film transistor driving circuit

• US 6,466,191 B1
• Filed: 12/14/1999
• Issued: 10/15/2002
• Est. Priority Date: 12/24/1998
• Status: Expired due to Term

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choi, Jae-Jin, Moon, Seung-Hwan, Kim, Jung-Hwan
• Primary Examiner(s): Shankar, Vijay
• Assistant Examiner(s): Patel, Nitin
• Application Number:
  US09/459,924
• Time in Patent Office: 1,036 Days
• Field of Search: 345/94, 345/95, 345/98, 345/89, 345/99
• US Class Current: 345/94
• CPC Class Codes: G09G 2320/0209 Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers

Abstract

A liquid crystal display of the present invention comprises a panel on which are formed a plurality of thin film transistors, a plurality of gate lines connected to gate electrodes of the thin film transistors, a plurality of data lines connected to source lines of the thin film transistors, a gate driver that applies a gate signal to the gate lines of the panel, a data voltage generator that generates data voltages which has many voltage levels, a data driver that applies to the data lines a data voltage for displaying picture signals on the liquid crystal display, a common electrode voltage generator that generates a common electrode voltage applied to a common electrode of the panel, a compensator for a distortion of common electrode voltage that is connected between the panel and the data voltage generator and compensates for the distortion of common electrode voltage by changing the data voltage. The crosstalk phenomenon of the LCD can be decreased in accordance with the present invention.

Claims

1. A liquid crystal display comprising:

a liquid crystal panel having a plurality of thin film transistors, a plurality of gate lines connected to gate electrodes of the thin film transistors, a plurality of data lines connected to source electrodes of the thin film transistors;

a gate driver that applies a gate signal to the gate lines;

a gray voltage generator for generating a gray voltage representing image signal;

a data driver that applies to the data lines the gray voltage for displaying an image on the liquid crystal display;

a common electrode voltage generator that generates a common electrode voltage applied to the common electrode; and

a compensator connected between said liquid crystal display panel and said gray voltage generator, said compensator compensating for the distortion of the common electrode voltage by modifying the gray voltage,

wherein said compensator compensates for the distortion of the common electrode voltage by coupling the waveform of the gray voltage to the waveform of the common electrode voltage, and

wherein said compensator comprises a capacitor connected between said common electrode and said gray voltage generator.

2. A liquid crystal display comprising:

a liquid crystal panel having a plurality of thin film transistors, a plurality of gate lines connected to gate electrodes of the thin film transistors, a plurality of data lines connected to source electrodes of the thin film transistors;

a gate driver that applies a gate signal to the gate lines;

a gray voltage generator for generating a gray voltage representing image signal;

a data driver that applies to the data lines the gray voltage for displaying an image on the liquid crystal display;

a common electrode voltage generator that generates a common electrode voltage applied to the common electrode; and

a compensator connected between said liquid crystal display panel and said gray voltage generator, said compensator compensating for the distortion of the common electrode voltage by modifying the gray voltage,

wherein said gray voltage generator comprises a plurality of resistors that are serially connected between a voltage source and a ground terminal, said gray voltage generator dividing the voltage of the voltage source to generate a plurality of gray voltages of different voltage levels, and

wherein said compensator comprises a capacitor connected between said common electrode and said gray voltage generator.

3. A liquid crystal display comprising:

a liquid crystal panel having a plurality of thin film transistors, a plurality of gate lines connected to gate electrodes of the thin film transistors, a plurality of data lines connected to source electrodes of the thin film transistors;

a gate driver that applies a gate signal to the gate lines;

a gray voltage generator for generating a gray voltage representing image signal;

a data driver that applies to the data lines the gray voltage for displaying an image on the liquid crystal display;

a common electrode voltage generator that generates a common electrode voltage applied to the common electrode; and

a compensator connected between said liquid crystal display panel and said gray voltage generator, said compensator compensating for the distortion of the common electrode voltage by modifying the gray voltage,

wherein said compensator comprises a capacitor that is connected between the common electrode and said gray voltage generator.

4. The liquid crystal display of claim 3, wherein said compensator further comprises an amplifier connected between the common electrode and the capacitor, the amplifier amplifying the distorted common electrode voltage to compensate for the distorted common electrode voltage measured at the common electrode.

5. The liquid crystal display of claim 3, wherein the capacitor is connected between the common electrode and the gray voltage output terminals that are provided between resistors of said gray voltage generator.

6. The liquid crystal display of claim 5, wherein the capacitance of the capacitor is bigger than the value of the horizontal synchronization period divided by the least resistance value of the resistor in said gray voltage generator.

7. The liquid crystal display of claim 5, wherein a plurality of capacitors are connected between the common electrode and a plurality of gray voltage output terminals provided between the resistors of said gray voltage generator.

8. The liquid crystal display of claim 7, wherein the capacitor comprises:

a first capacitor connected between the common electrode and a first gray voltage output terminal of said gray voltage generator; and

a second capacitor connected between the common electrode and a second gray voltage output terminal of said gray voltage generator.

9. The liquid crystal display of claim 8, wherein the first gray voltage output terminal is the output terminal of the maximum plus gray voltage and the second gray voltage output terminal is the output terminal of the maximum minus gray voltage.

10. The liquid crystal display of claim 8, wherein the first gray voltage output terminal is the output terminal of the second maximum plus gray voltage and the second gray voltage output terminal is the output terminal of the second maximum minus gray voltage.