Patent US3877016A successfully refreshed from Google Patents.
US3877016A
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Driver circuit for liquid crystal display
Assignee: Omron R&D Inc
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Filing: 1973-10-04
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Granted: 1975-04-08
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Expires: 1993-10-04
Abstract
Abstract A circuit for driving liquid crystal displays in which numerals or symbols are made up of a plurality of segments in which one terminal of like segments of each of a plurality of numerals or symbols are simultaneously energized with an a.c. voltage from a plurality of segment circuits which energize selected segments and in which the other terminals of all of the segments of each numeral or symbol are energized with an a.c. voltage from a plurality of digit circuits which energize selected numerals or symbols whereby the selected segments of selected digits display responsive to simultaneous application of a.c. voltages to the one and the other terminal.
Inventors
- 👤 Arnold J Jorgensen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:20
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/04; G09G3/16; G09G3/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
334 words
A driver circuit for a liquid crystal display having a predetermined threshold voltage and adapted to be connected to a d.c. voltage source, first and second a.c. voltage sources having substantially 180.degree. phase relationship, and a source of segment select pulses including a plurality of segment voltage control means, one for each segment of a numeral or symbol, one segment voltage control means connected to each of first terminals of like segments of a plurality of display numbers or symbols for controlling application of the d.c. voltage to said first terminals of like segments responsive to a segment select signal and said first a.c. voltage source to alternately apply said d.c. voltage to each of said first terminals, means responsive to the complement of the segment select pulses in the absence of segment select pulses to apply only a portion of said d.c. voltage to said first terminal of each of said like segments, said driver circuit also adapted to be connected to said second a.c. voltage source and a source of numeral or symbol select pulses, and also including a plurality of digit voltage control means one for each numeral or symbol, one digit voltage control means connected to second terminals of all segments in each one of said numerals or symbols for controlling application of voltage from said d.c. source to said second terminals responsive to a digit select pulse and said second a.c. voltage source to alternately apply said d.c. voltage to said plurality of second terminals, and means responsive to the complement of the digit select pulses in the absence of digit select pulses to apply only a portion of the d.c. voltage to said second terminals, whereby when the first and second terminals of a segment both have alternating d.c. voltage applied, the predetermined threshold of the segments is exceeded and the predetermined threshold of the segments is not exceeded when the alternating d.c. voltage is applied only to one or the other of said first and second terminals.
Claim 2
Dependent Claim
334 words
A driver circuit for a liquid crystal display having a predetermined threshold voltage and adapted to be connected to a d.c. voltage source, first and second a.c. voltage sources having substantially 180.degree. phase relationship, and a source of segment select pulses including a plurality of segment voltage control means, one for each segment of a numeral or symbol, one segment voltage control means connected to each of first terminals of like segments of a plurality of display numbers or symbols for controlling application of the d.c. voltage to said first terminals of like segments responsive to a segment select signal and said first a.c. voltage source to alternately apply said d.c. voltage to each of said first terminals, means responsive to the complement of the segment select pulses in the absence of segment select pulses to apply only a portion of said d.c. voltage to said first terminal of each of said like segments, said driver circuit also adapted to be connected to said second a.c. voltage source and a source of numeral or symbol select pulses, and also including a plurality of digit voltage control means one for each numeral or symbol, one digit voltage control means connected to second terminals of all segments in each one of said numerals or symbols for controlling application of voltage from said d.c. source to said second terminals responsive to a digit select pulse and said second a.c. voltage source to alternately apply said d.c. voltage to said plurality of second terminals, and means responsive to the complement of the digit select pulses in the absence of digit select pulses to apply only a portion of the d.c. voltage to said second terminals, whereby when the first and second terminals of a segment both have alternating d.c. voltage applied, the predetermined threshold of the segments is exceeded and the predetermined threshold of the segments is not exceeded when the alternating d.c. voltage is applied only to one or the other of said first and second terminals.
Claim 3
Dependent Claim
35 words
A driver circuit as in claim 1 wherein said segment voltage and digit voltage control means each include a switching transistor serving to alternately apply said d.c. voltage to the respective first and second terminals.
Claim 4
Dependent Claim
55 words
A driver circuit as in claim 2 wherein said segment voltage and digit voltage control means each include a second switching transistor connected in parallel with said first switching transistor to provide the response to absence of segment and digit select voltages to apply only a portion of said d.c. voltage to the respective terminals.
Claim 5
Dependent Claim
291 words
A driver circuit for liquid crystal displays including a d.c. voltage source, a first a.c. voltage source, a source of segment select pulses and a plurality of segment voltage control means, one for each segment of a numeral or symbol, one segment voltage control means connected to each of first terminals of like segments of a plurality of display numbers or symbols for controlling application of voltage from said d.c. source to said first terminals of like segments responsive to a segment select signal and the voltage from said first a.c. voltage source to alternately apply said d.c. voltage to said terminals, said control means being responsive to absence of segment select pulses to apply only a portion of said d.c. voltage to said first terminal of each of said like segments, a second a.c. voltage source having a 180.degree. phase relationship to said first a.c. voltage source, a source of numeral or symbol select pulses and a plurality of digit voltage control means one for each numeral or symbol, one digit voltage control means connected to second terminals of all segments of each of said numerals or symbols for controlling application of voltage from said source to said second terminals responsive to a digit select pulse and to said second a.c. voltage source to alternately apply said d.c. voltage to said second terminals, and means responsive to the absence of digit select pulses to apply only a portion of the d.c. voltage to said segments, whereby when the first and second terminals of a segment both have alternating d.c. voltage applied, the segments are energized and said segments are not energized when the alternating d.c. voltage is applied only to one or the other of said first and second terminals.
Claim 6
Dependent Claim
291 words
A driver circuit for liquid crystal displays including a d.c. voltage source, a first a.c. voltage source, a source of segment select pulses and a plurality of segment voltage control means, one for each segment of a numeral or symbol, one segment voltage control means connected to each of first terminals of like segments of a plurality of display numbers or symbols for controlling application of voltage from said d.c. source to said first terminals of like segments responsive to a segment select signal and the voltage from said first a.c. voltage source to alternately apply said d.c. voltage to said terminals, said control means being responsive to absence of segment select pulses to apply only a portion of said d.c. voltage to said first terminal of each of said like segments, a second a.c. voltage source having a 180.degree. phase relationship to said first a.c. voltage source, a source of numeral or symbol select pulses and a plurality of digit voltage control means one for each numeral or symbol, one digit voltage control means connected to second terminals of all segments of each of said numerals or symbols for controlling application of voltage from said source to said second terminals responsive to a digit select pulse and to said second a.c. voltage source to alternately apply said d.c. voltage to said second terminals, and means responsive to the absence of digit select pulses to apply only a portion of the d.c. voltage to said segments, whereby when the first and second terminals of a segment both have alternating d.c. voltage applied, the segments are energized and said segments are not energized when the alternating d.c. voltage is applied only to one or the other of said first and second terminals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |