US3820108A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Decoder and driver circuits particularly adapted for use with liquid crystal displays
Assignee: Refac International Ltd
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Filing: 1972-03-10
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Granted: 1974-06-25
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Expires: 1992-03-10
Abstract
Abstract A decoder-driver network for energizing a liquid crystal display used in a timepiece to cause the same to provide any one of a plurality of presentations according to any one of a number of coded formats. The decoder-driver circuit uses bidirectional devices arranged in series paths to minimize components and increase reliability.
Inventors
- 👤 N Luce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:26
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/04; G09G3/16; G09G3/18; G04; G04G; G04G9/00; G04G9/08; G04G9/12; H; H03; H03K; H03K21/00; H03K21/08
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
453 words
Apparatus used for driving a display, said display being of the type including a first common electrode and a plurality of display electrodes, said display adapted to be activated by a source of bidirectional potential having first and second terminals for being connected across said display with said first terminal connected to said common electrode of said display, said display capable of indicating any different one of a plurality of presentations according to which of said display electrodes are connected to said second terminal of said source, in combination therewith apparatus for selectively connecting said second terminal to any desired ones of said display electrodes, comprising: a. a plurality of bidirectional field effect transistors each having a source electrode, a drain electrode and a gate electrode, said field effect devices operative in a first state to provide a low impedance bidirectional current conducting path between said source and drain electrodes when said gate electrode is biased by a first operating potential and in a second state to provide a high impedance between said source and drain electrode when said gate is biased by a second operating potential, b. means for coupling said second terminal of said source to any desired one of said display electrodes including a series path formed by at least two of said field effect transistors having the source electrode of one directly connected to said desired one of said display electrodes and the drain electrode of said one directly connected to the source electrode of said other, with the drain electrode of said other directly connected to said second terminal of said source, c. a code generator capable of providing a series of codes each manifesting a different indication capable of selecting a different display presentation, said codes defined by two potential levels which correspond to either said first operating or said second operating potential dependEnt upon the code provided, said code generator having a plurality of output terminals each providing either of said operating potentials dependent upon said code provided, and d. means coupling a predetermined one of said output terminals of said code generator to said gate electrode of said one transistor and another predetermined one of said output terminals to said gate electrode of said other transistor, whereby when said code generator is providing said first operating potential at said predetermined output terminals, said display electrode is connected to said second terminal of said source through said low impedance path provided by said at least two field effect transistors both operating in said first state and to provide said high impedance path between said display electrode and said second source terminal when either of said predetermined code generator output terminals is providing said second operating potential.
Claim 2
Dependent Claim
453 words
Apparatus used for driving a display, said display being of the type including a first common electrode and a plurality of display electrodes, said display adapted to be activated by a source of bidirectional potential having first and second terminals for being connected across said display with said first terminal connected to said common electrode of said display, said display capable of indicating any different one of a plurality of presentations according to which of said display electrodes are connected to said second terminal of said source, in combination therewith apparatus for selectively connecting said second terminal to any desired ones of said display electrodes, comprising: a. a plurality of bidirectional field effect transistors each having a source electrode, a drain electrode and a gate electrode, said field effect devices operative in a first state to provide a low impedance bidirectional current conducting path between said source and drain electrodes when said gate electrode is biased by a first operating potential and in a second state to provide a high impedance between said source and drain electrode when said gate is biased by a second operating potential, b. means for coupling said second terminal of said source to any desired one of said display electrodes including a series path formed by at least two of said field effect transistors having the source electrode of one directly connected to said desired one of said display electrodes and the drain electrode of said one directly connected to the source electrode of said other, with the drain electrode of said other directly connected to said second terminal of said source, c. a code generator capable of providing a series of codes each manifesting a different indication capable of selecting a different display presentation, said codes defined by two potential levels which correspond to either said first operating or said second operating potential dependEnt upon the code provided, said code generator having a plurality of output terminals each providing either of said operating potentials dependent upon said code provided, and d. means coupling a predetermined one of said output terminals of said code generator to said gate electrode of said one transistor and another predetermined one of said output terminals to said gate electrode of said other transistor, whereby when said code generator is providing said first operating potential at said predetermined output terminals, said display electrode is connected to said second terminal of said source through said low impedance path provided by said at least two field effect transistors both operating in said first state and to provide said high impedance path between said display electrode and said second source terminal when either of said predetermined code generator output terminals is providing said second operating potential.
Claim 3
Dependent Claim
25 words
The apparatus according to claim 1 wherein said display comprises a liquid crystal display having a first common electrode and a plurality of segment electrodes.
Claim 4
Dependent Claim
46 words
The apparatus according to claim 1 wherein said plurality of bidirectional field effect transistors are a plurality of MOS devices each having a drain output electrode, a source common electrode and a gate input electrode and fabricated for bidirectional conduction between said source and drain electrodes.
Claim 5
Dependent Claim
60 words
The apparatus according to claim 1 wherein each of said plurality of transistors includes a first N channel MOS device and a second P channel MOS device each having a common connected source electrode and a common connected drain electrode, respectively corresponding to said common and output electrodes, with a separate gate input electrode, associated with each of said devices.
Claim 6
Dependent Claim
422 words
In a liquid crystal display of the type having a common electrode and a series of segment electrodes, said display adapted to be energized by a source of bidirectional potential, said source having a first terminal connected to said common electrode and a second terminal to be connected to any desired one of said segment electrodes, in combination therewith apparatus for selectively connecting said second terminal of said source to a desired one of said segment electrodes, according to a predetermined code format, comprising: a. a plurality of bidirectional field effect transistor devices, each having a gate input electrode, a source electrode and a drain electrode, and operative to provide in a first operating mode a low impedance bidirectional path between said source and drain electrode upon application of a first biasing potential to said gate electrode, and operative in a second mode presenting a high impedance between said source and drain electrodes upon application of a second biasing potential to said gate electrode, b. means for coupling at least two of said plurality of devices in a series path between a selected one of said segments and said second terminal of said bidirectional potential source, said remaining devices of said plurality being coupled in a similar series path between said other segments, each of said paths including at least two of said devices arranged with the source electrode of one of said devices connected to said selected segment, the drain of said device connected to the source of the other device and said drain of said other device connected to said second terminal of said bidirectional source, c. code generating means having a number of individual output terminals, each terminal capable of providing a first state corresponding to said first biasing potential a second state corresponding to said second biasing potential, and d. means coupling said gate electrode of said one device to a selected one of said output terminals and said gate electrode of said other device to another one of said output terminals, whereby each device has coupled to the associated gate electrode one of said output terminals of said code generating means, whereby when said code generating means is providing said first biasing potential, said selected segment is connected to said second terminal of said bidirectional source through said series low impedance path and when one of said output terminals of said code generating means is providing said second biasing potential, said selected segment is isolated from said second terminal of said bidirectional source by said high impedance.
Claim 7
Dependent Claim
422 words
In a liquid crystal display of the type having a common electrode and a series of segment electrodes, said display adapted to be energized by a source of bidirectional potential, said source having a first terminal connected to said common electrode and a second terminal to be connected to any desired one of said segment electrodes, in combination therewith apparatus for selectively connecting said second terminal of said source to a desired one of said segment electrodes, according to a predetermined code format, comprising: a. a plurality of bidirectional field effect transistor devices, each having a gate input electrode, a source electrode and a drain electrode, and operative to provide in a first operating mode a low impedance bidirectional path between said source and drain electrode upon application of a first biasing potential to said gate electrode, and operative in a second mode presenting a high impedance between said source and drain electrodes upon application of a second biasing potential to said gate electrode, b. means for coupling at least two of said plurality of devices in a series path between a selected one of said segments and said second terminal of said bidirectional potential source, said remaining devices of said plurality being coupled in a similar series path between said other segments, each of said paths including at least two of said devices arranged with the source electrode of one of said devices connected to said selected segment, the drain of said device connected to the source of the other device and said drain of said other device connected to said second terminal of said bidirectional source, c. code generating means having a number of individual output terminals, each terminal capable of providing a first state corresponding to said first biasing potential a second state corresponding to said second biasing potential, and d. means coupling said gate electrode of said one device to a selected one of said output terminals and said gate electrode of said other device to another one of said output terminals, whereby each device has coupled to the associated gate electrode one of said output terminals of said code generating means, whereby when said code generating means is providing said first biasing potential, said selected segment is connected to said second terminal of said bidirectional source through said series low impedance path and when one of said output terminals of said code generating means is providing said second biasing potential, said selected segment is isolated from said second terminal of said bidirectional source by said high impedance.
Claim 8
Dependent Claim
33 words
The apparatus according to claim 5, wherein said plurality of bidirectional devices comprises a plurality of MOS devices each having an output drain electrode, a common source electrode and an input gate electrode.
Claim 9
Dependent Claim
17 words
The apparatus according to claim 6, wherein said plurality of MOS devices are P channel MOS devices.
Claim 10
Dependent Claim
16 words
The apparatus according to claim 5, wherein said code generating means comprises a binary counting chain.
Claim 11
Dependent Claim
21 words
The apparatus according to claim 5 wherein said liquid crystal display has seven of said segment electrodes and one common electrode.
Claim 12
Dependent Claim
270 words
In a liquid crystal display of the type having a common electrode and a series of segment electrodes, said display adapted to be energized by a source of AC potential connected between said common electrode and any selected one of said segment electrodes, in combination therewith apparatus for selectively activating any segment according to a predetermined code format comprising: a. a plurality of MOS devices each having a gate, source and drain electrode, and operative to provide a low impedance bidirectional current conducting path between said source and drain electrodes, when said gate electrode is biased by a suitable operating potential, said devices arranged in a plurality of current conducting series path with at least a source electrode of a first MOS device connected to a drain electrode of another MOS device and said source electrode of said other connected to a drain electrode of a last MOS device, said series path formed between said segment electrodes and a suitable terminal associated with said source of AC potential, to provide a series of paths enabling a selected plurality of said segment electrodes to be connected to said source upon activation of said gate electrodes of said MOS devices; b. a code generator capable of providing a series of codes each manifesting a different indication capable of selecting a plurality of different segment connections to said source of AC potential; and c. means coupling certain preselected ones of said gate electrodes of said MOS devices to said code generator to cause certain of said series paths to provide said low impedance bidirectional paths for each one of said series of codes.
Claim 13
Dependent Claim
270 words
In a liquid crystal display of the type having a common electrode and a series of segment electrodes, said display adapted to be energized by a source of AC potential connected between said common electrode and any selected one of said segment electrodes, in combination therewith apparatus for selectively activating any segment according to a predetermined code format comprising: a. a plurality of MOS devices each having a gate, source and drain electrode, and operative to provide a low impedance bidirectional current conducting path between said source and drain electrodes, when said gate electrode is biased by a suitable operating potential, said devices arranged in a plurality of current conducting series path with at least a source electrode of a first MOS device connected to a drain electrode of another MOS device and said source electrode of said other connected to a drain electrode of a last MOS device, said series path formed between said segment electrodes and a suitable terminal associated with said source of AC potential, to provide a series of paths enabling a selected plurality of said segment electrodes to be connected to said source upon activation of said gate electrodes of said MOS devices; b. a code generator capable of providing a series of codes each manifesting a different indication capable of selecting a plurality of different segment connections to said source of AC potential; and c. means coupling certain preselected ones of said gate electrodes of said MOS devices to said code generator to cause certain of said series paths to provide said low impedance bidirectional paths for each one of said series of codes.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |