Claims
- 1. A driving method for driving an optical modulation device, wherein the device comprises a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns, and a chiral smectic liquid crystal, the picture elements in each row being selectively supplied with either a voltage for orienting the chiral smectic liquid crystal to one display state, or another voltage for orienting the chiral smectic liquid crystal to another display state, said driving method comprising the steps of:
- sequentially and periodically applying a scanning selection signal to the scanning electrodes to periodically select a particular scanning electrode, said scanning selection signal comprising a former voltage signal of a first voltage and a latter voltage signal of a second voltage different from the first voltage;
- applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode and an auxiliary signal having a waveform different from that of the information signal,
- wherein the picture elements on each periodically selected particular scanning electrode supplied with the former voltage signal are non-selectively erased into one display state,
- wherein a selected picture element on the particular scanning electrode supplied with the latter voltage signal is changed into the other display state depending on the selected information signal, and
- wherein a non-selected picture element on the particular scanning electrode supplied with the latter voltage signal is held in said one display state, thereby providing a periodically refreshed display picture.
- 2. A method according to claim 1, wherein said auxiliary signal has a voltage polarity opposite to that of the information signal with reference to a voltage level of a scanning electrode when not supplied with the scanning selection signal.
- 3. A method according to claim 1, wherein said chiral smectic liquid crystal is a liquid crystal developing ferroelectricity.
- 4. A display apparatus, comprising
- (a) a liquid crystal device including a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns, and a chiral smectic liquid crystal,
- (b) first means for sequentially and periodically applying a scanning selection signal comprising a first voltage signal and a second voltage signal to periodically select a particular scanning electrode, and
- (c) second means for applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode and an auxiliary signal having a waveform different from that of the information signal,
- wherein the picture elements on each periodically selected particular scanning electrode supplied with the former voltage signal are non-selectively erased into one display state,
- wherein a selected picture element on the particular scanning electrode supplied with the latter voltage signal is changed into the other display state depending on the selected information signal, and
- wherein a non-selected picture element on the particular scanning electrode supplied with the latter voltage signal is held in said one display state, thereby providing a periodically refreshed display picture.
- 5. An apparatus according to claim 4, wherein said auxiliary signal has a voltage polarity opposite to that of said information signal with reference to a voltage level of a scanning electrode when not supplied with said scanning selection signal.
- 6. An apparatus according to claim 4 wherein said chiral smectic liquid crystal is a liquid crystal developing ferroelectricity.
- 7. An driving method for driving an optical modulation device, wherein the device comprises a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns, and a chiral smectic liquid crystal, the picture elements in each row being selectively supplied with either a voltage for orienting the chiral smectic liquid crystal to one display state, or another voltage for orienting the chiral smectic liquid crystal to another display state, said driving method comprising the steps of:
- sequentially and periodically applying a scanning selection signal to the scanning electrodes to periodically select a particular scanning electrode, the scanning selection signal comprising a former voltage signal of a first voltage and a latter voltage signal of a second voltage different from the first voltage;
- applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, each data signal having a waveform so as to provide an alternating voltage applied to the picture element on a scanning electrode not supplied with said scanning selection signal,
- wherein the picture elements on each periodically selected particular scanning electrode supplied with the former voltage are non-selectively erased into one display state,
- wherein a selected picture element on the particular scanning electrode supplied with the latter voltage signal is changed into the other display state depending on the selected information signal, and
- wherein a non-selected picture element on the particular scanning electrode supplied with the latter voltage signal is held in said one display state, thereby providing a periodically refreshed display picture.
- 8. A method according to claim 7, wherein the alternating voltage has an average voltage value of zero.
- 9. A method according to claim 7, wherein said chiral smectic liquid crystal is a liquid crystal developing ferroelectricity.
- 10. A display apparatus, comprising:
- (a) a liquid crystal device including a plurality of picture elements arranged in the form of a matrix having a plurality of rows and a plurality of columns defined by intersections of scanning electrodes arranged in rows and signal electrodes arranged in columns, and a chiral smectic liquid crystal,
- (b) first means for sequentially and periodically applying a scanning selection signal comprising a first voltage signal and a second voltage signal to periodically select a particular scanning electrode, and
- (c) second means for applying data signals to the signal electrodes, each data signal comprising an information signal for selecting a display state of a picture element on the particular scanning electrode, each data signal having a waveform so as to provide an alternating voltage applied to the picture element on a scanning electrode not supplied with said scanning selection signal,
- wherein the picture elements on each periodically selected particular scanning electrode supplied with the former voltage signal are non-selectively erased into one display state,
- wherein a selected picture element on the particular scanning electrode supplied with the latter voltage signal is changed into the other display state depending on the selected information signal, and
- wherein a non-selected picture element on the particular scanning electrode supplied with the latter voltage signal is held in said one display state, thereby providing a periodically refreshed display picture.
- 11. An apparatus according to claim 10, wherein the alternative voltage has an average voltage value of zero.
- 12. An apparatus according to claim 10 wherein said chiral smectic liquid crystal is a liquid crystal developing ferroelectricity.
- 13. A liquid crystal apparatus, comprising:
- a liquid crystal device comprising a group of scanning electrodes and a group of signal electrodes intersecting each other to form an electrode matrix, and a liquid crystal having a memory function disposed so as to form a picture element at each intersection of the scanning electrodes and the signal electrodes; and
- drive means for:
- (a) sequentially and periodically applying a scanning selection signal, said scanning selection signal comprising a first voltage signal and a second voltage having a waveform different from that of the first voltage signal, and being applied in a period for one scanning electrode,
- (b) in a period of applying said first voltage signal, applying signals to the signal electrodes for uniformly causing an orientation state of said liquid crystal, thereby non-selectively erasing the picture elements on a scanning electrode to which the first voltage signal is applied,
- (c) in a period of applying said second voltage signal, applying signals to the signal electrodes for selectively causing either one orientation state or another orientation state of said liquid crystal, thereby selectively writing in the picture elements on the scanning electrode to which the second voltage signal is applied, and
- (d) applying an alternating voltage to the picture elements on the scanning electrodes not supplied with the scanning selection signal.
- 14. A liquid crystal apparatus according to claim 13, wherein said liquid crystal is a liquid crystal developing ferroelectricity.
- 15. A liquid crystal apparatus according to claim 13, wherein said liquid crystal is a chiral smectic liquid crystal.
- 16. A liquid crystal apparatus according to claim 13, wherein the voltage magnitude of said first voltage signal is larger than that of said second voltage signal.
- 17. A liquid crystal apparatus according to claim 13, wherein said alternating voltage has an average value of zero.
- 18. A driving method for a liquid crystal device comprising a group of scanning electrodes and a group of signal electrodes intersecting each other to form an electrode matrix, and a liquid crystal having a memory function disposed so as to form a picture element at each intersection of the scanning electrodes and the signal electrodes, said driving method comprising:
- (a) sequentially and periodically applying a scanning selection signal, the scanning selection signal comprising a first voltage signal and second voltage signal having a waveform different from that of the first voltage signal, and being applied in a period for one scanning electrode;
- (b) in a period of applying the first voltage signal, applying signals to the signal electrodes for uniformly causing an orientation state of the liquid crystal, thereby non-selectively erasing the picture elements on a scanning electrode to which the first voltage signal is applied;
- (c) in a period of applying the second voltage signal, applying signals to the signal electrodes for selectively causing either one orientation state or another orientation state of the liquid crystal, thereby selectively writing in the picture elements on the scanning electrode to which the second voltage signal is applied; and
- (d) applying an alternating voltage to the picture elements on the scanning electrodes not supplied with the scanning selection signal.
- 19. A driving method according to claim 18, wherein the liquid crystal is a liquid crystal developing ferroelectricity.
- 20. A driving method according to claim 18, wherein the liquid crystal is a chiral smectic liquid crystal.
- 21. A driving method according to claim 18, wherein the voltage magnitude of the first voltage signal is larger than that of the second voltage signal.
- 22. A driving method according to claim 18, wherein the alternating voltage has an average value of zero.
Priority Claims (4)
Number |
Date |
Country |
Kind |
59-10503 |
Jan 1984 |
JPX |
|
59-10504 |
Jan 1984 |
JPX |
|
59-263662 |
Dec 1984 |
JPX |
|
59-272357 |
Dec 1984 |
JPX |
|
Parent Case Info
This application is a division of application Ser. No. 08/206,211 filed on Mar. 3, 1994, now U.S. Pat. No. 5,559,616, which is a division of Ser. No. 08/079,215 filed on Jun. 21, 1993, now U.S. Pat. No. 5,296,953 which is a continuation of application Ser. No. 07/919,381 filed Jul. 29, 1992, now abandoned, which is a continuation of application Ser. No. 07/760,504 filed Sep. 16, 1991, now abandoned, which is a division of application Ser. No. 07/390,922 filed Aug. 8, 1989, now U.S. Pat. No. 5,092,665, which is a division of application Ser. No. 07/320,798 filed Mar. 9, 1989, now abandoned, which is a continuation of application Ser. No. 07/135,535 filed Dec. 17, 1987, now abandoned, which is a continuation of application Ser. No. 06/691,761 filed Jan. 15, 1985 now abandoned.
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Divisions (4)
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206211 |
Mar 1994 |
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79215 |
Jun 1993 |
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390922 |
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Continuations (4)
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919381 |
Jul 1992 |
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760504 |
Sep 1991 |
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135535 |
Dec 1987 |
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691761 |
Jan 1985 |
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