US6137462A
Expired / Lapsed
US
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Liquid crystal display driving circuit
Assignee: LG Display Co Ltd
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Filing: 1997-05-01
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Granted: 2000-10-24
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Expires: 2017-05-01
Abstract
Abstract Liquid crystal display (LCD) driving circuit in which a small number of voltage sources enable multi-gradation display and gamma correction without extra gamma correction circuits is disclosed. The LCD driving circuit includes a ramp wave generator for generating a plurality of ramp waves each having an appropriate tilt for each section along a T axis of a T-V (transmission-voltage) curve representing the light transmittivity of an LCD according to an applied voltage, a ramp wave selector for selecting one of the plurality of ramp waves according to input data, and a counter for adjusting the time the ramp wave outputted by the ramp wave selector is applied.
Inventors
- 👤 Jun-Hee Kim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:20
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/2007; G09G3/2011; G09G3/3611; G09G3/3685; G09G3/3688; G09G2310/00; G09G2310/02; G09G2310/0243; G09G2310/0259; G09G2320/00; G09G2320/02; G09G2320/0271; G09G2320/0276
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
87 words
A liquid crystal display (LCD) driving circuit comprising: a ramp wave generating means for generating a plurality of ramp waves each having an appropriate tilt for each section along a T axis of a T-V (transmission-voltage) curve representing the light transmittivity of an LCD according to an applied voltage; a ramp wave selecting means for selecting one of the plurality of ramp waves according to input data; and, a count means for adjusting the time the ramp wave outputted by the ramp wave selecting means is applied.
Claim 2
Dependent Claim
87 words
A liquid crystal display (LCD) driving circuit comprising: a ramp wave generating means for generating a plurality of ramp waves each having an appropriate tilt for each section along a T axis of a T-V (transmission-voltage) curve representing the light transmittivity of an LCD according to an applied voltage; a ramp wave selecting means for selecting one of the plurality of ramp waves according to input data; and, a count means for adjusting the time the ramp wave outputted by the ramp wave selecting means is applied.
Claim 3
Dependent Claim
66 words
The LCD driving circuit as claimed in claim 1, wherein the count means comprises: a counter for counting the input data in sequence; a switching part responsive to the counter for outputting the ramp wave selected by the ramp wave selecting means; and, a buffer for maintaining the ramp wave outputted by the switching part for a predetermined time after the switching part is turned off.
Claim 4
Dependent Claim
105 words
A liquid crystal display (LCD) driving circuit comprising: a voltage generating means for generating voltage sources each corresponding to sections along a T axis of a T-V (transmissivity-voltage) curve representing the light transmittivity of an LCD according to an applied voltage; a ramp wave generating means for generating ramp waves each having an appropriate tilt for each of the sections; an adding means for adding the voltage source and ramp wave generated from the voltage generating means and the ramp wave generating means, respectively, for a corresponding section; and, a count means for adjusting the time an adding result of the adding means is applied.
Claim 5
Dependent Claim
105 words
A liquid crystal display (LCD) driving circuit comprising: a voltage generating means for generating voltage sources each corresponding to sections along a T axis of a T-V (transmissivity-voltage) curve representing the light transmittivity of an LCD according to an applied voltage; a ramp wave generating means for generating ramp waves each having an appropriate tilt for each of the sections; an adding means for adding the voltage source and ramp wave generated from the voltage generating means and the ramp wave generating means, respectively, for a corresponding section; and, a count means for adjusting the time an adding result of the adding means is applied.
Claim 6
Dependent Claim
53 words
The LCD driving circuit as claimed in claim 3, wherein the voltage generating means comprises: a voltage generating part for generating a voltage source for each section along the a T axis of the T-V curve; and, a selecting part for outputting one of the plurality of voltage sources according to input data.
Claim 7
Dependent Claim
58 words
The LCD driving circuit as claimed in claim 3, wherein the ramp wave generating means comprises: a ramp wave generating part for generating a plurality of ramp waves having appropriate tilts at the sections set by the voltage generating means; and, a selecting part for selecting one of the plurality of ramp waves according to the input data.
Claim 8
Dependent Claim
74 words
The LCD driving circuit as claimed in claim 3, wherein each of the tilts of the ramp waves generated by the ramp wave generating means is ((V i+1 +V i )×1 H), in which V i+1 is a voltage of a section right after a predetermined number of the sections, and V i is a voltage of a section just prior to the section, and 1 H is a selecting time of line 1.
Claim 9
Dependent Claim
20 words
The LCD driving circuit as claimed in claim 3, wherein the adding means inlcudes an adder using an operational amplifier.
Claim 10
Dependent Claim
80 words
The LCD driving circuit as claimed in claim 3, wherein the count means comprises: a counter for counting a predetermined number of as many as predetermined steps between the sections set according to the input data; a switching means for outputting an adding result of the adding means when activated by the counter; and, a latch for maintaining the adding result of the adding means for a predetermined time after the switching means is turned off by the count means.
Claim 11
Dependent Claim
34 words
The LCD driving circuit as claimed in claim 8, wherein the time for counting by the counter plus the time for maintaining by the latch equals the selecting time 1 H of line 1.
Claim 12
Dependent Claim
34 words
The LCD driving circuit as claimed in claim 8, wherein while the counter is counting, an output of the adding means is increased from the selected voltage source to the selected ramp wave form.
Claim 13
Independent Claim
76 words
A method for driving a liquid crystal display (LCD) comprising the steps of: generating a plurality of ramp waves each having an appropriate tilt for each section along a T axis of a T-V (transmission-voltage) curve representing the light transmittivity of an LCD according to an applied voltage; selecting one of the plurality of ramp waves according to input data; and, adjusting a time the ramp wave outputted by the ramp wave selecting means is applied.
Claim 14
Independent Claim
76 words
A method for driving a liquid crystal display (LCD) comprising the steps of: generating a plurality of ramp waves each having an appropriate tilt for each section along a T axis of a T-V (transmission-voltage) curve representing the light transmittivity of an LCD according to an applied voltage; selecting one of the plurality of ramp waves according to input data; and, adjusting a time the ramp wave outputted by the ramp wave selecting means is applied.
Claim 15
Independent Claim
88 words
A method for driving an LCD comprising the steps of: generating voltage sources each corresponding to sections along a T axis of a T-V (transmissivity-voltage) curve representing the light transmittivity of an LCD according to an applied voltage; generating ramp waves each having an appropriate tilt for each of the sections; adding the voltage source and ramp wave generated from the voltage generating means and the ramp wave generating means, respectively, for a corresponding section; and, adjusting the time an adding result of the adding means is applied.
Claim 16
Independent Claim
88 words
A method for driving an LCD comprising the steps of: generating voltage sources each corresponding to sections along a T axis of a T-V (transmissivity-voltage) curve representing the light transmittivity of an LCD according to an applied voltage; generating ramp waves each having an appropriate tilt for each of the sections; adding the voltage source and ramp wave generated from the voltage generating means and the ramp wave generating means, respectively, for a corresponding section; and, adjusting the time an adding result of the adding means is applied.
Claim 17
Dependent Claim
74 words
A liquid crystal display (LCD) driving circuit comprising: a ramp wave generator producing a plurality of ramp waves, the ramp waves having different tilts; a ramp wave selector receiving the plurality of ramp waves and selecting one ramp wave corresponding to a first digital data; and a switching part applying the selected ramp wave to a panel of the LCD for a predetermined time, the predetermined time being determined by a second digital data.
Claim 18
Dependent Claim
74 words
A liquid crystal display (LCD) driving circuit comprising: a ramp wave generator producing a plurality of ramp waves, the ramp waves having different tilts; a ramp wave selector receiving the plurality of ramp waves and selecting one ramp wave corresponding to a first digital data; and a switching part applying the selected ramp wave to a panel of the LCD for a predetermined time, the predetermined time being determined by a second digital data.
Claim 19
Dependent Claim
26 words
The liquid crystal display (LCD) driving circuit in claim 13, the circuit further including a counter receiving the second digital data and controlling the switching part.
Claim 20
Dependent Claim
56 words
The liquid crystal display (LCD) driving circuit in claim 13, the circuit further including: a voltage generator producing a plurality of DC voltages; a voltage selector receiving the plurality of DC voltages and selecting one DC voltage corresponding to the first digital data; and an adder adding the selected ramp wave and the selected DC voltage.
Claim 21
Dependent Claim
25 words
The liquid crystal display (LCD) driving circuit in claim 15, wherein the first digital data and second digital data comprise all bits of display data.
Claim 22
Dependent Claim
26 words
The liquid crystal display (LCD) driving circuit in claim 15, the circuit further including a counter receiving the second digital data and controlling the switching part.
Claim 23
Dependent Claim
25 words
The liquid crystal display (LCD) driving circuit in claim 13, wherein the first digital data and second digital data comprise all bits of display data.
Claim 24
Dependent Claim
23 words
The liquid crystal display (LCD) driving circuit in claim 13, the circuit further including a buffer between the switching part and the panel.
Claim 25
Dependent Claim
20 words
The liquid crystal display (LCD) driving circuit in claim 13, wherein the second digital data includes the first digital data.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-10-24 | 2004-04-24 | 2004-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-10-24 | 2008-04-24 | 2008-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-10-24 | 2012-04-24 | 2012-10-24 | $7700.00 | Window Closed / Lapsed |