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US6300928B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Scanning circuit for driving liquid crystal display

Assignee: LG Display Co Ltd
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Filing: 1998-07-09
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Granted: 2001-10-09
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Expires: 2018-07-09
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Abstract

Abstract A scanning circuit that can minimize the number of input signals and switch signals applied to row lines of a liquid crystal panel, and reduce deterioration of a circuit is disclosed. The circuit includes input signal lines and a plurality of substantially identical stages cascade-connected to the input signal lines to produce a plurality of phase delayed scanning signals. Each stage has an input terminal and an output terminal. Also, each stage is provided with output circuitry comprising a push-pull amplifier including pull-up and pull-down transistors having respective conduction paths connected in series with the output terminal thereof and respective control electrodes, the push-pull amplifier having a supply terminal for applying one of the phase delayed scanning signals, input circuitry responsive to scanning pulse applied to the input terminal for generating first and second control signals which are coupled to the control electrodes of the pull-up and pull-down transistors for conditioning the push-pull amplifier to provide output scanning pulses, and means for raising a voltage of the first control signal to be applied to the control electrode of the pull-up transistor.

Inventors

  • 👤 Young Dae Kim

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 12:36
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G11; G11C; G11C19/00; G11C19/18; G11C19/182; G11C19/184; G09G3/3611; G09G3/3674; G09G3/3677; G11C19/28

Claims Analysis

Total Claims: 29
Claim 1
Independent Claim 176 words
A scanning circuit comprising a plurality of cascaded scanning stages, each of the scanning stages having an input terminal and an output terminal, the scanning circuit including means for generating phase delayed scanning signals and means for receiving an input signal, the scanning stages comprising: output circuitry comprising a push-pull amplifier including a pull-up transistor and a pull-down transistor having respective conduction paths connected in series with the output terminal, the pull-up transistor having a control electrode and the pull-down transistor having a control electrode, the push-pull amplifier having a supply terminal for receiving one of the phase delayed scanning signals; input circuitry responsive to a scanning pulse applied to the input terminal for generating first and second control signals that are respectively coupled to the control electrodes of the pull-up transistor and a pull-down transistor for conditioning the push-pull amplifier to provide output scanning pulses; and means responsive to a signal at the output terminal for raising a voltage of the first control signal to be applied to the control electrode of the pull-up transistor.
Claim 2
Dependent Claim 176 words
A scanning circuit comprising a plurality of cascaded scanning stages, each of the scanning stages having an input terminal and an output terminal, the scanning circuit including means for generating phase delayed scanning signals and means for receiving an input signal, the scanning stages comprising: output circuitry comprising a push-pull amplifier including a pull-up transistor and a pull-down transistor having respective conduction paths connected in series with the output terminal, the pull-up transistor having a control electrode and the pull-down transistor having a control electrode, the push-pull amplifier having a supply terminal for receiving one of the phase delayed scanning signals; input circuitry responsive to a scanning pulse applied to the input terminal for generating first and second control signals that are respectively coupled to the control electrodes of the pull-up transistor and a pull-down transistor for conditioning the push-pull amplifier to provide output scanning pulses; and means responsive to a signal at the output terminal for raising a voltage of the first control signal to be applied to the control electrode of the pull-up transistor.
Claim 3
Dependent Claim 75 words
The scanning circuit as set forth in claim 1 , wherein the input circuitry includes a first transistor having a conduction path connected to the control electrode of the pull-up transistor, and a control electrode and a first electrode that are connected to the input terminal; and a second transistor having a conduction path coupled in series with the conduction path of the first transistor and connected to the control electrode of the pull-up transistor.
Claim 4
Dependent Claim 82 words
The scanning circuit as set forth in claim 2 , wherein the input circuitry further includes a third transistor having a conduction path connected to the control electrode of the pull-down transistor and a control electrode connected to the input terminal; and a fourth transistor having a conduction path coupled in series with the conduction path of the third transistor and the control electrode of the pull-down transistor, and a control electrode connected to the output terminal of a subsequent cascaded stage.
Claim 5
Dependent Claim 38 words
The scanning circuit as set forth in claim 3 , further comprising means for supplementing a potential to the control electrode of the pull-down transistor periodically during a time interval at which the pull-up transistor is turned off.
Claim 6
Dependent Claim 49 words
The scanning circuit as set forth in claim 4 , wherein the potential supplementing means includes a fifth transistor having a conduction path connected between the control electrode of the fourth transistor and the supply terminal, and a control electrode connected to the control electrode of the pull-down transistor.
Claim 7
Dependent Claim 22 words
The scanning circuit as set forth in claim 3 , further comprising means for accelerating a turning-off speed of the pull-down transistor.
Claim 8
Dependent Claim 46 words
The scanning circuit as set forth in claim 6 , wherein the accelerating means includes a fifth transistor having a conduction path coupled in parallel with the conduction path of the third transistor, and a control electrode connected to the control electrode of the pull-up transistor.
Claim 9
Dependent Claim 45 words
The scanning circuit as set forth in claim 7 , wherein the accelerating means further includes a sixth transistor having a conduction path cascade-connected to the conduction path of the fifth transistor, and a control electrode connected to the conduction path of the fifth transistor.
Claim 10
Dependent Claim 69 words
The scanning circuit as set forth in claim 1 , wherein the input circuitry includes a diode having a conduction path connected between the input terminal and the control electrode of the pull-up transistor, and an electrode connected to the input terminal; and a transistor having a conduction path coupled in series with the conduction path of the diode and connected to the control electrode of the pull-up transistor.
Claim 11
Dependent Claim 31 words
The scanning circuit as set forth in claim 1 , wherein the voltage raising means includes a capacitor connected to the output terminal and the control electrode of the pull-up transistor.
Claim 12
Dependent Claim 161 words
A scanning circuit comprising a plurality of cascaded scanning stages, each of the scanning stages having an input terminal and an output terminal, the scanning circuit including means for generating phase delayed scanning signals and means for receiving an input signal, the scanning stages comprising: output circuitry comprising a push-pull amplifier including a pull-up transistor and a pull-down transistor having respective conduction paths connected in series with the output terminal and respective control electrodes, the push-pull amplifier having a supply terminal for receiving one of the phase delayed scanning signals; input circuitry responsive to a scanning pulse applied to the input terminal for generating first and second control signals that are coupled to the control electrodes of the pull-up and pull-down transistors for conditioning the push-pull amplifier to provide output scanning pulses; and means for accelerating a tuming-off speed of the pull-down transistor by discharging a voltage at the control electrode of the pull-down transistor selectively in one of two paths.
Claim 13
Dependent Claim 161 words
A scanning circuit comprising a plurality of cascaded scanning stages, each of the scanning stages having an input terminal and an output terminal, the scanning circuit including means for generating phase delayed scanning signals and means for receiving an input signal, the scanning stages comprising: output circuitry comprising a push-pull amplifier including a pull-up transistor and a pull-down transistor having respective conduction paths connected in series with the output terminal and respective control electrodes, the push-pull amplifier having a supply terminal for receiving one of the phase delayed scanning signals; input circuitry responsive to a scanning pulse applied to the input terminal for generating first and second control signals that are coupled to the control electrodes of the pull-up and pull-down transistors for conditioning the push-pull amplifier to provide output scanning pulses; and means for accelerating a tuming-off speed of the pull-down transistor by discharging a voltage at the control electrode of the pull-down transistor selectively in one of two paths.
Claim 14
Dependent Claim 75 words
The scanning circuit as set forth in claim 11 , wherein the input circuitry includes a first transistor having a conduction path connected to the control electrode of the pull-up transistor, and a control electrode and a first electrode that are connected to the input terminal; and a second transistor having a conduction path coupled in series with the conduction path of the first transistor and connected to the control electrode of the pull-up transistor.
Claim 15
Dependent Claim 85 words
The scanning circuit as set forth in claim 12 , wherein the input circuitry further includes a third transistor having a conduction path connected to the control electrode of the pull-down transistor and a control electrode connected to the input terminal; and a fourth transistor having a conduction path coupled in series with the conduction path of the third transistor and the control electrode of the pull-down transistor, and a control electrode connected to the output terminal of one of the plurality of cascaded stages.
Claim 16
Dependent Claim 38 words
The scanning circuit as set forth in claim 13 , further comprising means for supplementing a potential to the control electrode of the pull-down transistor periodically during a time interval at which the pull-up transistor is turned off.
Claim 17
Dependent Claim 49 words
The scanning circuit as set forth in claim 14 , wherein the potential supplementing means includes a fifth transistor having a conduction path connected between the control electrode of the fourth transistor and the supply terminal, and a control electrode connected to the control electrode of the pull-down transistor.
Claim 18
Dependent Claim 46 words
The scanning circuit as set forth in claim 13 , wherein the accelerating means includes a fifth transistor having a conduction path coupled in parallel with the conduction path of the third transistor, and a control electrode connected to the control electrode of the pull-up transistor.
Claim 19
Dependent Claim 45 words
The scanning circuit as set forth in claim 16 , wherein the accelerating means further includes a sixth transistor having a conduction path cascade-connected to the conduction path of the fifth transistor, and a control electrode connected to the conduction path of the fifth transistor.
Claim 20
Dependent Claim 69 words
The scanning circuit as set forth in claim 11 , wherein the input circuitry includes a diode having a conduction path connected between the input terminal and the control electrode of the pull-up transistor, and an electrode connected to the input terminal; and a transistor having a conduction path coupled in series with the conduction path of the diode and connected to the control electrode of the pull-up transistor.
Claim 21
Dependent Claim 158 words
A scanning circuit comprising a plurality of cascaded scanning stages, each of said scanning stages having an input terminal and an output terminal, the scanning circuit including means for generating phase delayed scanning signals and means for receiving an input signal, the scanning stages comprising: output circuitry comprising a push-pull amplifier including a pull-up transistor and a pull-down transistor having respective conduction paths connected in series with the output terminal and respective control electrodes, the push-pull amplifier having a supply terminal for receiving one of the phase delayed scanning signals; input circuitry responsive to a scanning pulse applied to the input terminal for generating first and second control signals that are coupled to the control electrodes of the pull-up and pull-down transistors for conditioning the push-pull amplifier to provide output scanning pulses; and means for supplementing a potential to the control electrode of the pull-down transistor during a time interval at which the pull-up transistor is turned off.
Claim 22
Dependent Claim 158 words
A scanning circuit comprising a plurality of cascaded scanning stages, each of said scanning stages having an input terminal and an output terminal, the scanning circuit including means for generating phase delayed scanning signals and means for receiving an input signal, the scanning stages comprising: output circuitry comprising a push-pull amplifier including a pull-up transistor and a pull-down transistor having respective conduction paths connected in series with the output terminal and respective control electrodes, the push-pull amplifier having a supply terminal for receiving one of the phase delayed scanning signals; input circuitry responsive to a scanning pulse applied to the input terminal for generating first and second control signals that are coupled to the control electrodes of the pull-up and pull-down transistors for conditioning the push-pull amplifier to provide output scanning pulses; and means for supplementing a potential to the control electrode of the pull-down transistor during a time interval at which the pull-up transistor is turned off.
Claim 23
Dependent Claim 75 words
The scanning circuit as set forth in claim 19 , wherein the input circuitry includes a first transistor having a conduction path connected to the control electrode of the pull-up transistor, and a control electrode and a first electrode that are connected to the input terminal; and a second transistor having a conduction path coupled in series with the conduction path of the first transistor and connected to the control electrode of the pull-up transistor.
Claim 24
Dependent Claim 82 words
The scanning circuit as set forth in claim 20 , wherein the input circuitry further includes a third transistor having a conduction path connected to the control electrode of the pull-down transistor and a control electrode connected to the input terminal; and a fourth transistor having a conduction path coupled in series with the conduction path of the third transistor and the control electrode of the pull-down transistor, and a control electrode connected to the output terminal of a subsequent cascaded stage.
Claim 25
Dependent Claim 22 words
The scanning circuit as set forth in claim 21 , further comprising means for accelerating a turning-off speed of the pull-down transistor.
Claim 26
Dependent Claim 46 words
The scanning circuit as set forth in claim 22 , wherein the accelerating means includes a fifth transistor having a conduction path coupled in parallel with the conduction path of the third transistor, and a control electrode connected to the control electrode of the pull-up transistor.
Claim 27
Dependent Claim 44 words
The scanning circuit as set forth in claim 23 , wherein the accelerating means further includes a sixth transistor having a conduction path cascade-connected to the conduction path of the fifth transistor, and a control electrode connected to the conduction path of the transistor.
Claim 28
Dependent Claim 69 words
The scanning circuit as set forth in claim 19 , wherein the input circuitry includes a diode having a conduction path connected between the input terminal and the control electrode of the pull-up transistor, and an electrode connected to the input terminal; and a transistor having a conduction path coupled in series with the conduction path of the diode and connected to the control electrode of the pull-up transistor.
Claim 29
Dependent Claim 49 words
The scanning circuit as set forth in claim 21 , wherein the potential supplementing means includes a fifth transistor having a conduction path connected between the control electrode of the fourth transistor and the supply terminal, and a control electrode connected to the control electrode of the pull-down transistor.

References Cited (Backward Citations)

US5410583A Cited
US5510805A Cited
US5434899A Cited
US5701136A Cited
US5859630A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2004-10-08 2005-04-09 2005-10-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2008-10-08 2009-04-09 2009-10-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2012-10-08 2013-04-09 2013-10-09 $7700.00 Window Closed / Lapsed

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