Patent US3902169A successfully refreshed from Google Patents.
US3902169A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drive system for liquid crystal display units
Assignee: Sharp Corp
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Filing: 1973-09-19
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Granted: 1975-08-26
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Expires: 1993-09-19
Abstract
Abstract The present disclosure is directed toward a system for driving a plurality of liquid crystal display units each having a common electrode, a plurality of segment electrodes and a liquid crystal composition interposed between the said electrodes. The liquid crystal compositions are energized and activated upon the application of a voltage higher than a given threshold voltage between said electrodes which initiates scattering of light therein. When the liquid crystal display units are desired to be deenergized, a voltage lower than the threshold voltage is applied between said electrodes. In a dynamic mode of operation, as contrasted to ordinary dynamic drive systems, the less than threshold voltage is applied in an alternating fashion across the liquid crystal compositions desired not to be selected. Such application of alternating bias voltage to the liquid crystal composition in its non-selected state is to ensure a long life and a high speed of response and so on.
Inventors
- 👤 Isamu Washizuka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:58
CPC Classifications
G; G04; G04G; G04G9/00; G04G9/08; G04G9/12; G04G9/122; G09; G09G; G09G3/00; G09G3/04; G09G3/16; G09G3/18
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
57 words
A drive system for driving a liquid crystal unit having a given threshold voltage value which initiates a change in the optical characteristics of said liquid crystal unit, said drive system comprising means for applying an alternating polarity voltage lower than the threshold value to the liquid crystal unit when it is not desired to be ON.
Claim 2
Dependent Claim
57 words
A drive system for driving a liquid crystal unit having a given threshold voltage value which initiates a change in the optical characteristics of said liquid crystal unit, said drive system comprising means for applying an alternating polarity voltage lower than the threshold value to the liquid crystal unit when it is not desired to be ON.
Claim 3
Dependent Claim
32 words
A drive system as defined in claim 1 wherein the voltage to the liquid crystal unit to be selected is chosen to be more than twice as high as the threshold value.
Claim 4
Dependent Claim
193 words
A liquid crystal display system comprising a plurality of liquid crystal display units, each unit having a common electrode, a plurality of segment electrodes the combinations of which define displaying patterns, as well as a liquid crystal composition between said common and said segment electrodes having a given threshold voltage value which initiates a change in the optional characteristics of said liquid crystal unit, connection means for commonly connecting the corresponding segment electrodes in the individual display units. first selection means for repeatedly applying segment selection signals to the individual groups of the commonly connected segment electrodes, second selection means for applying timing signals to the common electrodes to enable time sharing selections of the plural display units, and amplitude determination means for so determining the relation between the applied segment selection signals and the timing signals that a voltage higher than the threshold value is applied in alternating polarities between the common electrode and selected segment electrodes when said liquid crystal is to be activated and the less than threshold value voltage is applied in alternating polarities between said common and said segment electrodes when said liquid crystal is to be non-activated.
Claim 5
Dependent Claim
193 words
A liquid crystal display system comprising a plurality of liquid crystal display units, each unit having a common electrode, a plurality of segment electrodes the combinations of which define displaying patterns, as well as a liquid crystal composition between said common and said segment electrodes having a given threshold voltage value which initiates a change in the optional characteristics of said liquid crystal unit, connection means for commonly connecting the corresponding segment electrodes in the individual display units. first selection means for repeatedly applying segment selection signals to the individual groups of the commonly connected segment electrodes, second selection means for applying timing signals to the common electrodes to enable time sharing selections of the plural display units, and amplitude determination means for so determining the relation between the applied segment selection signals and the timing signals that a voltage higher than the threshold value is applied in alternating polarities between the common electrode and selected segment electrodes when said liquid crystal is to be activated and the less than threshold value voltage is applied in alternating polarities between said common and said segment electrodes when said liquid crystal is to be non-activated.
Claim 6
Dependent Claim
208 words
A liquid crystal display system for displaying information stored in a storage register by means of a plurality of liquid crystal display units each unit having a common electrode, a plurality of segment electrodes defining representation of the information to be displayed, and a liquid crystal composition filled between the common electrode and the segment electrodes, said display system comprising timing signal generator means for generating a train of sequentially phase-shifted signals, timing signal conversion means for modifying the individual timing signals into signal waveforms of alternating polarity within each period of the timing signals, timing selecting means for applying the alternating polarity voltage timing signals to the common electrodes of the individual display unit to enable time sharing selection for the display units, decoder means for decoding the information stored in the storage register and translating the decoded information into segment selection signals for the segment type liquid crystal display units, segment selection signal conversion means for modifying the individUal segment selection signals into signal waveforms of alternating polarity within each period of the timing signals, and segment selection means for applying the alternating polarity voltage segment signals to individual segment electrodes in phase opposition to said alternating polarity voltage timing signals applied to said common electrodes.
Claim 7
Dependent Claim
208 words
A liquid crystal display system for displaying information stored in a storage register by means of a plurality of liquid crystal display units each unit having a common electrode, a plurality of segment electrodes defining representation of the information to be displayed, and a liquid crystal composition filled between the common electrode and the segment electrodes, said display system comprising timing signal generator means for generating a train of sequentially phase-shifted signals, timing signal conversion means for modifying the individual timing signals into signal waveforms of alternating polarity within each period of the timing signals, timing selecting means for applying the alternating polarity voltage timing signals to the common electrodes of the individual display unit to enable time sharing selection for the display units, decoder means for decoding the information stored in the storage register and translating the decoded information into segment selection signals for the segment type liquid crystal display units, segment selection signal conversion means for modifying the individUal segment selection signals into signal waveforms of alternating polarity within each period of the timing signals, and segment selection means for applying the alternating polarity voltage segment signals to individual segment electrodes in phase opposition to said alternating polarity voltage timing signals applied to said common electrodes.
Claim 8
Dependent Claim
183 words
In a system for driving a liquid crystal unit comprising a pair of electrodes and a liquid crystal composition held between the pair of the electrodes, said unit having a threshold voltage value at which it will turn on and below which it will turn off and exhibiting a delayed response to a voltage across said electrodes in excess of said threshold value, the improvement comprising: circuit means for producing a bipolar alternating bias voltage having a positive polarity component and a negative polarity component with reference to zero potential, both of said components having an amplitude greater than zero potential but less than the value of said threshold voltage and insufficient to turn on the liquid crystal unit; and connection means interposed between said circuit means and said liquid crystal unit for applying said bias voltage and hence said positive and negative polarity components across said electrodes of said liquid crystal unit when it is not desired to be on to substantially reduce the response delay of said liquid crystal unit to voltages across said electrodes in excess of said threshold voltage.
Claim 9
Dependent Claim
183 words
In a system for driving a liquid crystal unit comprising a pair of electrodes and a liquid crystal composition held between the pair of the electrodes, said unit having a threshold voltage value at which it will turn on and below which it will turn off and exhibiting a delayed response to a voltage across said electrodes in excess of said threshold value, the improvement comprising: circuit means for producing a bipolar alternating bias voltage having a positive polarity component and a negative polarity component with reference to zero potential, both of said components having an amplitude greater than zero potential but less than the value of said threshold voltage and insufficient to turn on the liquid crystal unit; and connection means interposed between said circuit means and said liquid crystal unit for applying said bias voltage and hence said positive and negative polarity components across said electrodes of said liquid crystal unit when it is not desired to be on to substantially reduce the response delay of said liquid crystal unit to voltages across said electrodes in excess of said threshold voltage.
Claim 10
Independent Claim
235 words
A system for driving a liquid crystal unit comprising a pair of electrodes and a liquid crystal composition held between said pair of electrodes, said unit having a threshold voltage vale at which it will turn on and below which it will turn off and exhibiting a delayed response to a voltage across said electrodes in excess of said threshold value, said system comprising: circuit means for producing bipolar alternating turnon and turn-off voltages having a positive polarity component and a negative polarity component with reference to zero potential, said positive and negative components of said turn-on voltage having an amplitude sufficient to turn-on said liquid crystal unit, said positive and negative components of said turn-off voltage having an amplitude which is intermediate said turn-on voltage level and zero potential and hence insufficient to turn on the liquid crystal unit; and connection means interposed between said circuit means and said liquid crystal unit for applying said positive and negative polarity components of said turn-on voltage across said liquid crystal unit when it is desired to be on and for applying said positive and negative polarity components of said turn-off voltage across said liquid crystal unit when it is desired to be off to increase the useful life of said liquid crystal unit and to substantially reduce the response delay of said liquid crystal unit to voltages across said electrodes in excess of said threshold voltage.
Claim 11
Independent Claim
235 words
A system for driving a liquid crystal unit comprising a pair of electrodes and a liquid crystal composition held between said pair of electrodes, said unit having a threshold voltage vale at which it will turn on and below which it will turn off and exhibiting a delayed response to a voltage across said electrodes in excess of said threshold value, said system comprising: circuit means for producing bipolar alternating turnon and turn-off voltages having a positive polarity component and a negative polarity component with reference to zero potential, said positive and negative components of said turn-on voltage having an amplitude sufficient to turn-on said liquid crystal unit, said positive and negative components of said turn-off voltage having an amplitude which is intermediate said turn-on voltage level and zero potential and hence insufficient to turn on the liquid crystal unit; and connection means interposed between said circuit means and said liquid crystal unit for applying said positive and negative polarity components of said turn-on voltage across said liquid crystal unit when it is desired to be on and for applying said positive and negative polarity components of said turn-off voltage across said liquid crystal unit when it is desired to be off to increase the useful life of said liquid crystal unit and to substantially reduce the response delay of said liquid crystal unit to voltages across said electrodes in excess of said threshold voltage.
Claim 12
Independent Claim
241 words
A system for driving cycle-by-cycle a liquid crystal unit comprising a pair of electrodes and a liquid crystal composition held between the pair of the electrodes, said unit having a threshold voltage value at which it will turn on and below which it will turn off and exhibiting a delayed response to a voltage across said electrodes in excess of said threshold value, said system comprising circuit means for producing bipolar alternating turnon and turn-off voltages having a positive polarity component and a negative polarity component with reference to zero potential within the same cycle, said positive and negative components of said turn-on voltage having an amplitude sufficient to turn-on said liquid crystal unit, said positive and negative components of said turn-off voltage having an amplitude which is intermediate said turn-on voltage level and zero potential and hence insufficient to turn on the liquid crystal unit; and connection means interposed between said circuit means and said liquid crystal unit for applYing said positive and negative polarity components of said turn-on voltage across said liquid crystal unit when it is desired to be on and for applying said positive and negative polarity components of said turn-off voltage across said liquid crystal unit when it is desired to be off to increase the useful life of said liquid crystal unit and to substantially reduce the response delay of said liquid crystal unit to voltages across said electrodes in excess of said threshold voltage.
Claim 13
Independent Claim
241 words
A system for driving cycle-by-cycle a liquid crystal unit comprising a pair of electrodes and a liquid crystal composition held between the pair of the electrodes, said unit having a threshold voltage value at which it will turn on and below which it will turn off and exhibiting a delayed response to a voltage across said electrodes in excess of said threshold value, said system comprising circuit means for producing bipolar alternating turnon and turn-off voltages having a positive polarity component and a negative polarity component with reference to zero potential within the same cycle, said positive and negative components of said turn-on voltage having an amplitude sufficient to turn-on said liquid crystal unit, said positive and negative components of said turn-off voltage having an amplitude which is intermediate said turn-on voltage level and zero potential and hence insufficient to turn on the liquid crystal unit; and connection means interposed between said circuit means and said liquid crystal unit for applYing said positive and negative polarity components of said turn-on voltage across said liquid crystal unit when it is desired to be on and for applying said positive and negative polarity components of said turn-off voltage across said liquid crystal unit when it is desired to be off to increase the useful life of said liquid crystal unit and to substantially reduce the response delay of said liquid crystal unit to voltages across said electrodes in excess of said threshold voltage.
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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |