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US3903518A
Expired / Lapsed
US
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Driving system for liquid crystal display device
Assignee: Hitachi Ltd
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Filing: 1973-11-27
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Granted: 1975-09-02
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Expires: 1993-11-27
Abstract
Abstract A driving system for liquid crystal display devices comprises a plurality of sets of liquid crystal display devices. Each set includes a liquid crystal whose state changes visually at a visual threshold voltage and first and second electrodes which serve to apply potential differences to the liquid crystal. Potentials of a high level, a low level and a medium level are selectively applied to the respective first electrodes, and the potentials of the high level and the low level are selectively applied to the respective second electrodes. The potential difference between the high level potential to be applied to the first electrodes and the low level potential to be applied to the second electrode, and the potential difference between the low level potential to be applied to the first electrodes and the high level potential to be applied to the second electrodes have values larger than the visual threshold voltage. The potential difference between the medium level potential to be applied to the first electrodes and the high or low level potential to be applied to the second electrodes has a value smaller than the visual threshold voltage.
Inventors
- 👤 Yoshikazu Hatsukano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:19
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/13306; G04; G04G; G04G9/00; G04G9/02; G04G9/06; G04G9/062
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
196 words
A system for selectively driving a plurality of liquid crystal display devices, each liquid crystal display device including a first common electrode, a plurality of second electrodes spaced apart from said first electrode and from each other, and a liquid crystal medium the visible state of which changes from a first state to a second state at a predetermined voltage difference thereacross, said liquid crystal medium being interposed between said first and second electrodes, said system comprising: first means, coupled to a first common electrode of one of said display devices, for selectively applying thereto a voltage corresponding to a selected one of first, second and third voltage levels; and second means, coupled to selected ones of the second electrodes of said plurality of liquid crystal display devices for selectively applying thereto a voltage corresponding to a selected one of said first, second and third voltages; wherein the absolute value of the difference between said first and second voltages is equal to at least said predetermined voltage difference, and the respective absolute values of the differences between said first and third voltage and between said second and third voltages is less than said predetermined voltage difference.
Claim 2
Independent Claim
196 words
A system for selectively driving a plurality of liquid crystal display devices, each liquid crystal display device including a first common electrode, a plurality of second electrodes spaced apart from said first electrode and from each other, and a liquid crystal medium the visible state of which changes from a first state to a second state at a predetermined voltage difference thereacross, said liquid crystal medium being interposed between said first and second electrodes, said system comprising: first means, coupled to a first common electrode of one of said display devices, for selectively applying thereto a voltage corresponding to a selected one of first, second and third voltage levels; and second means, coupled to selected ones of the second electrodes of said plurality of liquid crystal display devices for selectively applying thereto a voltage corresponding to a selected one of said first, second and third voltages; wherein the absolute value of the difference between said first and second voltages is equal to at least said predetermined voltage difference, and the respective absolute values of the differences between said first and third voltage and between said second and third voltages is less than said predetermined voltage difference.
Claim 3
Dependent Claim
64 words
A system according to claim 1, further including means for controlling the application of said first, second and third voltages by said first and second means, so that said third voltage is supplied by said first and second means simultaneously, and exclusively of the application of said first or second voltage and said second or first voltage by said first and second means, respectively.
Claim 4
Independent Claim
347 words
A system for selectively driving a plurality of liquid crystal display devices, each liquid crystal display device including a first common electrode, a plurality of second electrodes spaced apart from said first electrode and from each other, and a liquid crystal medium the visible state of which changes from a first state to a second state at a predetermined voltage difference thereacross, said liquid crystal medium being interposed between said first and second electrodes, said system comprising: first means, coupled to a first common electrode of one of said display devices, for selectively applying thereto a voltage corresponding to a selected one of first, second and third voltage levels, said first means including first and second switching elements, each Having an input electrode, an output electrode, and a control electrode, the input electrodes of said elements being respectively connected to said first and second voltages, the output elelctrodes of said elements being connected to said first common electrode, and a first logic means, connected to the control electrodes of said first and second switching elements, for making said first switching element conductive in a first period of time to supply said first voltage to said first common electrode, for making said second switching element conductive in a second period of time to supply said second voltage to said second common electrode, and for making both of said first and second switching elements simultaneously conductive to supply said third voltage which is an intermediate value between said first and second value determined by the resistance ratio of the first and second switching elements; and second means, coupled to selected ones of the second electrodes of said plurality of crystal display devices, for selectively applying thereto a voltage corresponding to a selected one of said first and second voltages; wherein the absolute value of the difference between said first and second voltages is equal to at least said predetermined voltage difference, and the respective absolute values of the differences between said first and third voltage and between said second and third voltages is less than said predetermined voltage difference.
Claim 5
Independent Claim
347 words
A system for selectively driving a plurality of liquid crystal display devices, each liquid crystal display device including a first common electrode, a plurality of second electrodes spaced apart from said first electrode and from each other, and a liquid crystal medium the visible state of which changes from a first state to a second state at a predetermined voltage difference thereacross, said liquid crystal medium being interposed between said first and second electrodes, said system comprising: first means, coupled to a first common electrode of one of said display devices, for selectively applying thereto a voltage corresponding to a selected one of first, second and third voltage levels, said first means including first and second switching elements, each Having an input electrode, an output electrode, and a control electrode, the input electrodes of said elements being respectively connected to said first and second voltages, the output elelctrodes of said elements being connected to said first common electrode, and a first logic means, connected to the control electrodes of said first and second switching elements, for making said first switching element conductive in a first period of time to supply said first voltage to said first common electrode, for making said second switching element conductive in a second period of time to supply said second voltage to said second common electrode, and for making both of said first and second switching elements simultaneously conductive to supply said third voltage which is an intermediate value between said first and second value determined by the resistance ratio of the first and second switching elements; and second means, coupled to selected ones of the second electrodes of said plurality of crystal display devices, for selectively applying thereto a voltage corresponding to a selected one of said first and second voltages; wherein the absolute value of the difference between said first and second voltages is equal to at least said predetermined voltage difference, and the respective absolute values of the differences between said first and third voltage and between said second and third voltages is less than said predetermined voltage difference.
Claim 6
Dependent Claim
94 words
A system according to claim 3, wherein said second means includes third and fourth switching elements, each having an input electrode, an output electrode, and a control electrode, the input electrodes of said third and fourth switching elements being respectively connected to said first and second voltages, the output electrodes of said third and fourth switching elements being connected to a selected one of said second electrodes, and a second logic means connected to the control electrodes of said third and fourth switching elements for making said third and fourth switch elements conductive complementarily.
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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) | 1978-09-01 | 1979-03-03 | 1979-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-01 | 1983-03-03 | 1983-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-01 | 1987-03-03 | 1987-09-02 | $7700.00 | Window Closed / Lapsed |