Active matrix liquid crystal display and method of driving the same

Claim 2

An active matrix liquid crystal display comprising: a liquid crystal panel having a liquid crystal layer, display electrodes to which data voltages are selectively applied and a common electrode to which a common voltage is applied, said liquid crystal layer being disposed between said display electrodes and said common electrode to define liquid crystal cells and said liquid crystal display being driven by common and data voltages, the polarity of the data voltage, relative to the common voltage, periodically inverting; detection means for detecting distortion of a common voltage applied to said common electrode and producing a detected distortion waveform of the common voltage; an integration circuit which receives the detected distortion waveform of the common voltage detected by the detection means and produces a correction voltage output by averaging the detected distortion waveform of the common voltage as an integration waveform, and which correction voltage output is supplied thereby to said common electrode to correct the distortion of said common voltage; and said detection means further comprises a monitoring resistor which couples the correction voltage output of said integration circuit to said common electrode, a connection between said monitoring resistor and said common electrode being used for detecting distortion of said common voltage.

Claim 3

An active matrix liquid crystal display as claimed in claim 1, wherein: said detection means further comprises a differential amplifier coupled to said common electrode and said monitoring resistor; said monitoring resistor is coupled between said common electrode and the output of said correction circuit; and an output of said differential amplifier is coupled to said integration circuit and is used to detect distortion of said common voltage.

Claim 4

An active matrix liquid crystal display as claimed in claim 1, wherein said integration circuit further comprises reset means for periodically resetting and initializing the correction voltage output produced by said integration circuit.

Claim 5

An active matrix liquid crystal display as claimed in claim 3, wherein said integration circuit is reset during a period starting when a corresponding gate is turned OFF and ending when a polarity of a data voltage is inverted.

Claim 6

An active matrix liquid crystal display comprising: a liquid crystal panel having a liquid crystal layer, display electrodes to which data voltages are selectively applied and a common electrode to which a common voltage is applied, said liquid crystal layer being disposed between said display electrodes and said common electrode to define liquid crystal cells and said liquid crystal display being driven by common and data voltages, the polarity of the data voltage, relative to the common voltage, periodically inverting; detection means for detecting distortion of a common voltage applied to said common electrode and producing a detected distortion waveform of the common voltage; and an integration unit which receives the detected distortion waveform of the common voltage detected by the detection means and produces a correction voltage output by averaging the detected distortion waveform of the common voltage as an integration waveform, and which correction voltage output is supplied thereby to said common electrode to correct the distortion of said common voltage, said integration unit further comprising reset means for periodically resetting and initializing the correction voltage output by said integration unit, a first integration circuit receiving a first reset signal for resetting a first output voltage of said first integration circuit, a second integration circuit receiving a second reset signal for resetting a second output voltage of said second integration circuit, and a selector for selecting one of the first output voltage and the second output voltage which is not reset, said selector providing the correction voltage output.

Claim 7

An active matrix liquid crystal display comprising: a liquid crystal panel having a liquid crystal layer, display electrodes to which data voltages are selectively applied and a common electrode to which a common voltage is applied, said liquid crystal layer being disposed between said display electrodes and said common electrode to define liquid crystal cells and said liquid crystal display being driven by common and data voltages, the polarity of the data voltage, relative to the common voltage, periodically inverting; detection means for detecting distortion of a common voltage applied to said common electrode and producing a detected distortion waveform of the common voltage; and an integration unit which receives the detected distortion waveform of the common voltage detected by the detection means and produces a correction voltage output by averaging the detected distortion waveform of the common voltage as an integration waveform, and which correction voltage output is supplied thereby to said common electrode to correct the distortion of said common voltage, said integration unit further comprising reset means for periodically resetting and initializing the correction voltage output by said integration unit, a first integration circuit receiving a first reset signal for resetting a first output voltage of said first integration circuit, a second integration circuit receiving a second reset signal for resetting a second output voltage of said second integration circuit, and a selector for selecting one of the first output voltage and the second output voltage which is not reset, said selector providing the correction voltage output.

Claim 8

An active matrix liquid crystal display comprising: a liquid crystal panel having a liquid crystal layer, display electrodes to which data voltages are selectively applied and a common electrode to which a common voltage is applied, said liquid crystal layer being disposed between said display electrodes and said common electrode to define liquid crystal cells and said liquid crystal display being driven by common and data voltages, the polarity of the data voltage, relative to the common voltage, periodically inverting; detection means for detecting distortion of said common voltage applied to said common electrode and producing a detected distortion waveform of the common voltage; a correction circuit comprising an integration circuit producing a correction voltage output by averaging the detected distortion waveform of the common voltage as an integration waveform, and providing the correction voltage output to said common electrode to correct the distortion of said common voltage; and said detection means further comprises a monitoring resistor which couples the correction voltage output of said integration circuit to said common electrode, a connection between said monitoring resistor and said common electrode being used for detecting distortion of said common voltage.

Claim 9

An active matrix liquid crystal display comprising: a liquid crystal panel having a liquid crystal layer, display electrodes to which data voltages are selectively applied and a common electrode to which a common voltage is applied, said liquid crystal layer being disposed between said display electrodes and said common electrode to define liquid crystal cells and said liquid crystal display being driven by common and data voltages, the polarity of the data voltage, relative to the common voltage, periodically inverting; detection means for detecting distortion of said common voltage applied to said common electrode and producing a detected distortion waveform of the common voltage; a correction circuit comprising an integration circuit producing a correction voltage output by averaging the detected distortion waveform of the common voltage as an integration waveform, and providing the correction voltage output to said common electrode to correct the distortion of said common voltage; and said detection means further comprises a monitoring resistor which couples the correction voltage output of said integration circuit to said common electrode, a connection between said monitoring resistor and said common electrode being used for detecting distortion of said common voltage.

Claim 10

An active matrix liquid crystal display as recited in claim 6, wherein said detection means further comprises a differential amplifier having a first input, a second input and an output, said output coupled to said correction circuit, said first input coupled to a reference common voltage source, said common electrode and said monitoring resistor, and said second input coupled to said monitoring resistor and said common electrode, said differential amplifier producing a detected common voltage.

Claim 11

An active matrix liquid crystal display as recited in claim 7, wherein a resistor is coupled to said second input of said differential amplifier and said output of said differential amplifier.

Claim 12

An active matrix liquid crystal display as recited in claim 6, wherein said detection means further comprises: a differential amplifier having a first input for receiving a detected common voltage, a second input for receiving a reference common voltage, and an output for supplying a correction voltage; and a variable resistor for adjusting an amplification factor of the differential amplifier, said variable resistor being coupled to said first input of said differential amplifier and to said output of said differential amplifier.

Claim 13

An active matrix liquid crystal display as recited in claim 9, wherein said integration circuit further comprises a capacitor coupled to said first input of said differential amplifier and said output of said differential amplifier.

Claim 14

An active matrix liquid crystal display comprising: a liquid crystal panel having a liquid crystal layer, display electrodes to which data voltages are selectively applied and a common electrode to which a common voltage is applied, said liquid crystal layer being disposed between said display electrodes and said common electrode to define liquid crystal cells and said liquid crystal display being driven by common and data voltages, the polarity of the data voltage, relative to the common voltage, periodically inverting; a detector detecting distortion of a common voltage applied to said common electrode and producing a detected distortion waveform of the common voltage; an integration circuit receiving the detected distortion waveform of the common voltage detected by the detector and producing a correction voltage output by averaging the detected distortion waveform of the common voltage as an integration waveform, and which correction voltage output is supplied thereby to said common electrode to correct the distortion of said common voltage; and said detector further comprises a monitoring resistor which couples the correction voltage output of said integration circuit to said common electrode, a connection between said monitoring resistor and said common electrode being used for detecting distortion of said common voltage.

Claim 15

An active matrix liquid crystal display comprising: a liquid crystal panel having a liquid crystal layer, display electrodes to which data voltages are selectively applied and a common electrode to which a common voltage is applied, said liquid crystal layer being disposed between said display electrodes and said common electrode to define liquid crystal cells and said liquid crystal display being driven by common and data voltages, the polarity of the data voltage, relative to the common voltage, periodically inverting; a detector detecting distortion of a common voltage applied to said common electrode and producing a detected distortion waveform of the common voltage; an integration circuit receiving the detected distortion waveform of the common voltage detected by the detector and producing a correction voltage output by averaging the detected distortion waveform of the common voltage as an integration waveform, and which correction voltage output is supplied thereby to said common electrode to correct the distortion of said common voltage; and said detector further comprises a monitoring resistor which couples the correction voltage output of said integration circuit to said common electrode, a connection between said monitoring resistor and said common electrode being used for detecting distortion of said common voltage.

Claim 16

An active matrix liquid crystal display as claimed in claim 11, wherein: said detector further comprises a differential amplifier coupled to said common electrode and said monitoring resistor; said monitoring resistor is coupled between said common electrode and the output of said correction circuit; and an output of said differential amplifier is coupled to said integration circuit and is used to detect distortion of said common voltage.

Claim 17

An active matrix liquid crystal display as claimed in claim 11, wherein said integration circuit further comprises a reset circuit periodically resetting and initializing the correction voltage output produced by said integration circuit.

Claim 18

An active matrix liquid crystal display as claimed in claim 13, wherein said integration circuit is reset during a period starting when a corresponding gate is turned OFF and ending when a polarity of a data voltage is inverted.

Claim 19

An active matrix liquid crystal display comprising: a liquid crystal panel having a liquid crystal layer, display electrodes to which data voltages are selectively applied and a common electrode to which a common voltage is applied, said liquid crystal layer being disposed between said display electrodes and said common electrode to define liquid crystal cells and said liquid crystal display being driven by common and data voltages, the polarity of the data voltage, relative to the common voltage, periodically inverting; a detector detecting distortion of a common voltage applied to said common electrode and producing a detected distortion waveform of the common voltage; and an integration unit which receives the detected distortion waveform of the common voltage detected by the detector and produces a correction voltage output by averaging the detected distortion waveform of the common voltage as an integration waveform, and which correction voltage output is supplied thereby to said common electrode to correct the distortion of said common voltage, said integration unit further comprising a reset circuit periodically resetting and initializing the correction voltage output by said integration unit, a first integration circuit receiving a first reset signal resetting a first output voltage of said first integration circuit, a second integration circuit receiving a second reset signal resetting a second output voltage of said second integration circuit, and a selector selecting one of the first output voltage and the second output voltage which is not reset, said selector providing the correction voltage output.

Claim 20

An active matrix liquid crystal display comprising: a liquid crystal panel having a liquid crystal layer, display electrodes to which data voltages are selectively applied and a common electrode to which a common voltage is applied, said liquid crystal layer being disposed between said display electrodes and said common electrode to define liquid crystal cells and said liquid crystal display being driven by common and data voltages, the polarity of the data voltage, relative to the common voltage, periodically inverting; a detector detecting distortion of a common voltage applied to said common electrode and producing a detected distortion waveform of the common voltage; and an integration unit which receives the detected distortion waveform of the common voltage detected by the detector and produces a correction voltage output by averaging the detected distortion waveform of the common voltage as an integration waveform, and which correction voltage output is supplied thereby to said common electrode to correct the distortion of said common voltage, said integration unit further comprising a reset circuit periodically resetting and initializing the correction voltage output by said integration unit, a first integration circuit receiving a first reset signal resetting a first output voltage of said first integration circuit, a second integration circuit receiving a second reset signal resetting a second output voltage of said second integration circuit, and a selector selecting one of the first output voltage and the second output voltage which is not reset, said selector providing the correction voltage output.

Claim 21

An active matrix liquid crystal display comprising: a liquid crystal panel having a liquid crystal layers display electrodes to which data voltages are selectively applied and a common electrode to which a common voltage is applied, said liquid crystal layer being disposed between said display electrodes and said common electrode to define liquid crystal cells and said liquid crystal display being driven by common and data voltages, the polarity of the data voltage, relative to the common voltage, periodically inverting; a detector detecting distortion of said common voltage applied to said common electrode and producing a detected distortion waveform of the common voltage; a correction circuit comprising an integration circuit producing a correction voltage output by averaging the detected distortion waveform of the common voltage as an integration waveform, and providing the correction voltage output to said common electrode to correct the distortion of said common voltage; said detector further comprises a monitoring resistor which couples the correction voltage output of said integration circuit to said common electrode, a connection between said monitoring resistor and said common electrode being used for detecting distortion of said common voltage.

Claim 22

An active matrix liquid crystal display comprising: a liquid crystal panel having a liquid crystal layers display electrodes to which data voltages are selectively applied and a common electrode to which a common voltage is applied, said liquid crystal layer being disposed between said display electrodes and said common electrode to define liquid crystal cells and said liquid crystal display being driven by common and data voltages, the polarity of the data voltage, relative to the common voltage, periodically inverting; a detector detecting distortion of said common voltage applied to said common electrode and producing a detected distortion waveform of the common voltage; a correction circuit comprising an integration circuit producing a correction voltage output by averaging the detected distortion waveform of the common voltage as an integration waveform, and providing the correction voltage output to said common electrode to correct the distortion of said common voltage; said detector further comprises a monitoring resistor which couples the correction voltage output of said integration circuit to said common electrode, a connection between said monitoring resistor and said common electrode being used for detecting distortion of said common voltage.

Claim 23

An active matrix liquid crystal display as recited in claim 16, wherein said detector further comprises a differential amplifier having a first input, a second input and an output, said output coupled to said correction circuit, said first input coupled to a reference common voltage source, said common electrode and said monitoring resistor, and said second input coupled to said monitoring resistor and said common electrode, said differential amplifier producing a detected common voltage.

Claim 24

An active matrix liquid crystal display as recited in claim 17, wherein a resistor is coupled to said second input of said differential amplifier and said output of said differential amplifier.

Claim 25

An active matrix liquid crystal display as recited in claim 18, wherein said detector further comprises: a differential amplifier having a first input for receiving a detected common voltage, a second input for receiving a reference common voltage, and an output for supplying a correction voltage; and a variable resistor for adjusting an amplification factor of the differential amplifier, said variable resistor being coupled to said first input of said differential amplifier and to said output of said differential amplifier.

Claim 26

An active matrix liquid crystal display as recited in claim 19, wherein said integration circuit further comprises a capacitor coupled to said first input of said differential amplifier and said output of said differential amplifier.