Time-sharing driving method for ferroelectric liquid crystal display

• US 4,548,476 A
• Filed: 01/03/1984
• Issued: 10/22/1985
• Est. Priority Date: 01/14/1983
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kaneko, Syuzo
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Gallivan, Richard F.
• Application Number:
  US06/567,500
• Time in Patent Office: 658 Days
• Field of Search: 350/350 S, 350/333
• US Class Current: 345/97
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G06K 15/1252 using an array of light modulators, e.g. a linear array
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2320/0209 Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
• CPC Class Codes: G09G 3/3629 using liquid crystals having memory effects, e.g. ferroelectric liquid crystals
• CPC Class Codes: H04N 1/19505 Scanning picture elements spaced apart from one another in at least one direction
• CPC Class Codes: H04N 1/19515 in two directions

Abstract

In a time-sharing driving method for a device comprising electrode matrix wherein the electrode matrix comprises two electrode groups oppositely spaced from each other, each comprising a plurality of electrodes, the two electrode groups being arranged so as to intersect with each other to form matrix intersecting points, one electrode group being assigned to serve as a row electrode while the other electrode group is assigned to serve as a signal electrode, voltage being applied to each row electrode in a time-sharing manner, the time-sharing driving method is characterized in that voltage applied to a selected point in an addressed row electrode is in a direction opposite to that of voltage applied to the other matrix intersecting points.

Claims

1. In a time-sharing driving method for a device comprising an electrode matrix which comprises a pair of electrode groups oppositely spaced from each other, each comprising a plurality of electrodes, said pair of electrode groups intersecting with each other to form matrix intersecting points, one electrode group being assigned to serve as scanning electrodes,

a scanning electrode being addressed and subject to application of voltage in a time-sharing manner,

the improvement wherein

the direction of the voltage applied to a selected matrix intersecting point in the scanning electrode addressed at a time is opposite to that of the voltage applied to the other matrix intersecting points.

2. A time-sharing driving method according to claim 1, wherein a ferroelectric liquid crystal is interposed between said pair of electrode groups oppositely spaced from each other.

3. A time-sharing driving method according to claim 2, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

4. In a time-sharing driving method for a device comprising an electrode matrix comprising a pair of electrode groups oppositely spaced from each other, each comprising a plurality of electrodes, said pair of electrode groups intersecting with each other to form matrix intersecting points, one electrode group being assigned to serve as scanning electrodes while the other electrode group is assigned to serve as signal electrodes, a scanning electrode being addressed and subject to application of voltage in a time-sharing manner, the improvement wherein the voltages applied to said scanning electrodes and said signal electrodes are in such amounts that the polarity of voltage value D₂ -D₄ is different from that of the other voltage values D₂ -D₃, D₁ -D₄ and D₁ -D₃,

wherein D₄ is a voltage applied to an addressed scanning electrode, D₃ is a voltage applied to a non-addressed scanning electrode, D₂ is a voltage applied to a signal electrode selected from the plurality of signal electrodes, and D₁ is a voltage applied to the other signal electrodes.

5. A time-sharing driving method according to claim 4, wherein a ferroelectric liquid crystal is interposed between said pair of electrode groups oppositely spaced from each other.

6. A time-sharing driving method according to claim 5, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

7. In a time-sharing method for a device comprising an electrode matrix which comprises a pair of electrode groups oppositely spaced from each other, each comprising a plurality of electrodes, said pair of electrode groups intersecting with each other to form matrix intersecting points, one electrode group being assigned to serve as scanning electrodes while the other electrode group is assigned to serve as signal electrodes, a scanning electrode being addressed and subject to application of voltage in a time-sharing manner, the improvement wherein the voltages applied to said scanning electrodes and said signal electrodes are in such amounts that the following conditions are satisfied:

space="preserve" listing-type="equation">b.sub.3 <

b.sub.2 <

b.sub.4 <

b.sub.1

wherein b₄ is a voltage applied to an addressed scanning electrode, b₃ is a voltage applied to a non-addressed scanning electrode, b₂ is a voltage applied to a signal electrode selected from the plurality of signal electrodes and b₁ is a voltage applied to the other signal electrodes.

8. A time-sharing driving method according to claim 7, wherein the voltage b₄ has a positive polarity, and the voltage b₃ has a negative polarity.

9. A time-sharing driving method according to claim 7, wherein a ferroelectric liquid crystal is interposed between said two electrode groups oppositely spaced from each other.

10. A time-sharing driving method according to claim 9, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

11. In a time-sharing method for a matrix electrode array wherein the matrix electrode array comprises two electrode groups oppositely spaced from each other, each comprising a plurality of electrodes, said two electrode groups being arranged so as to intersect with each other, one electrode group being assigned to serve as scanning electrodes while the other electrode group is assigned to serve as signal electrodes,

a scanning electrode being addressed and subject to application of voltage in a time-sharing manner, the voltages applied to said scanning electrodes and said signal electrodes are in such amounts that the following conditions are satisfied:

space="preserve" listing-type="equation">B.sub.3 >

B.sub.2 >

B.sub.4 >

B.sub.1

wherein B₄ is a voltage applied to an addressed scanning electrode, B₃ is a voltage applied to a non-addressed scanning electrode, B₂ is a voltage applied to a signal electrode selected from the plurality of signal electrodes and B₁ is a voltage applied to the other signal electrodes.

12. A time-sharing driving method according to claim 11, wherein the voltage B₄ has negative polarity while the voltage B₃ has positive polarity.

13. A time-sharing driving method according to claim 11, wherein a ferroelectric liquid crystal is interposed between said two electrode groups oppositely spaced from each other.

14. A time-sharing driving method according to claim 13, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

15. In a time-sharing driving method for a device comprising an electrode matrix which comprises a pair of electrode groups oppositely spaced from each other, each comprising a plurality of electrodes, said pair of electrode groups intersecting with each other to form matrix intersecting points, one electrode group being assigned to serve as scanning electrodes while the other electrode group is assigned to serve as signal electrodes, a scanning electrode being addressed and subject to application of voltage in a time-sharing manner,

the improvement wherein

a. the direction of the voltage applied to a selected intersecting point in the scanning electrode addressed at a time is opposite to that of the voltage applied to the other matrix intersecting points, and

b. there is provided a time interval for applying an OFF signal within an addressing time interval.

16. A time-sharing driving method according to claim 15, wherein the OFF signal is applied to the scanning electrodes.

17. A time-sharing driving method according to claim 16 wherein the voltage of the OFF signal applied to the scanning electrode is the same voltage as that applied to scanning electrodes which are not addressed.

18. A time-sharing driving method according to claim 15, wherein the OFF signal is applied to the signal electrodes.

19. A time-sharing driving method according to claim 18, wherein the voltage of the OFF signal applied to signal electrodes is the same voltage as that applied to non-selected signal electrodes.

20. A time-sharing driving method according to claim 15, wherein the OFF signals are applied to the scanning electrodes and the signal electrodes.

21. A time-sharing driving method according to claim 20 wherein the voltage of the OFF signal applied to the scanning electrode is the same voltage as that applied to scanning electrodes which are not addressed.

22. A time-sharing driving method according to claim 20, wherein the voltage of the OFF signal applied to said selected signal electrode and non-selected signal electrodes is the same voltage as that applied to non-selected signal electrodes.

23. A time-sharing driving method according to claim 15, wherein said OFF signal is applied at a time interval immediately before an address is shifted to the subsequent address.

24. A time-sharing driving method according to claim 15, wherein a ferroelectric liquid crystal is interposed between said two electrode groups.

25. A time-sharing driving method according to claim 24, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

26. A time-sharing driving method for a liquid crystal device comprising shutters arranged in a plurality of rows, each shutter comprising a pair of oppositely spaced electrodes and a ferroelectric liquid crystal interposed therebetween, comprising:

addressing and subjecting said plurality of rows of shutters to application of voltage row by row in a time sharing manner, wherein a first voltage signal is applied to a shutter in an addressed row of shutters, and a second voltage signal is applied to another shutter in the addressed row of shutters, said first and second voltage signals having opposite directions with each other.

27. A time-sharing driving method according to claim 26, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

28. A time-sharing driving method according to claim 27, wherein said chiral smectic liquid crystal is a chiral smectic C liquid crystal.

29. A time-sharing driving method according to claim 26, wherein an OFF signal is applied to the respective shutters in the addressed row after the application of the first or second voltage signal.

30. A time-sharing driving method for a liquid crystal device comprising shutters arranged in a plurality of rows, each shutter comprising a pair of oppositely spaced electrodes and a ferroelectric liquid crystal interposed therebetween having a first and a second stable orientation, comprising addressing and subjecting said plurality of rows of shutters to application of voltage row by row in a time-sharing manner, wherein a first voltage signal causing the ferroelectric liquid crystal to take said first stable orientation is applied to a shutter in an addressed row of shutters and a second voltage signal causing the ferroelectric liquid crystal to take said second stable orientation is applied to another shutter in the addressed row of shutters, said first and second voltage signals having opposite directions with each other, and

a voltage signal causing the ferroelectric crystal to take said first stable orientation is applied to the shutters in the non-addressed rows of shutters.

31. A time-sharing driving method according to claim 30, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

32. A time-sharing driving method according to claim 31, wherein said chiral smectic liquid crystal is a chiral smectic C liquid crystal.

33. A time-sharing driving method according to claim 30, wherein an OFF signal is applied to the respective shutters in the addressed row after the application of the first or second voltage signal.

34. A time-sharing driving method for a liquid crystal device comprising shutters arranged in a plurality of rows and in a staggered relationship between the rows, each shutter comprising a pair of oppositely spaced electrodes and a ferroelectric liquid crystal interposed therebetween having a first and a second stable orientation, comprising:

addressing and subjecting said plurality of rows of shutters to application of voltage row by row in a time-sharing manner, wherein a first voltage signal causing the ferroelectric liquid crystal to take said first stable orientation is applied to a shutter in an addressed row of shutters, and a second voltage signal causing the ferroelectric liquid crystal to take said second stable orientation is applied to another shutter in the addressed row of shutters, said first and second voltage signals having opposite directions with each other.

35. A time-sharing driving method according to claim 34, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

36. A time-sharing driving method according to claim 35, wherein said chiral smectic liquid crystal is a chiaral smectic C liquid crystal.

37. A time-sharing driving method according to claim 34, wherein an OFF signal is applied to the respective shutters in the addressed row after the application of the first or second voltage signal.

38. A time-sharing driving method according to claim 34, wherein said shutters are arranged in 2 or 3 rows.

39. A liquid crystal apparatus, comprising:

a light source and a liquid crystal device disposed adjacent to the light source, said liquid crystal device comprising;

shutters arranged in a plurality of rows, each shutter comprising a pair of oppositely spaced electrodes and a ferroelectric liquid crystal interposed therebetween having a first stable orientation forming a light-transmissive state and a second stable orientation forming a light-interrupting state, and

means for addressing and applying voltage signals to said plurality of rows of shutters row by row in a time-sharing manner, said voltage signals comprising a first voltage signal for causing the ferroelectric liquid crystal to take said first stable orientation and a second voltage signal for causing the ferroelectric liquid crystal to take said second stable orientation, said first and second voltage signals having opposite directions with each other.

40. A liquid crystal apparatus according to claim 39, further comprising a photosensitive member disposed opposite to the light source with the liquid crystal device therebetween so that light from the light source will be selectively transmitted through the liquid crystal device and irradiated onto the photosensitive member.

41. A liquid crystal apparatus according to claim 40, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

42. A liquid crystal apparatus according to claim 41, wherein said chiral smectic liquid crystal is a chiral smectic C liquid crystal.

43. A liquid crystal apparatus, comprising:

a light source and a liquid crystal device disposed adjacent to the light source, said liquid crystal device comprising;

shutters arranged in a plurality of rows and in a staggered relationship between the rows, each shutter comprising a pair of oppositely spaced electrodes and a ferroelectric liquid crystal interposed therebetween having a first stable orientation forming a light-interrupting state and a second stable orientation forming a light-transmissive state, and

means for addressing and applying voltage signals to said plurality of rows of shutters row by row in a time-sharing manner;

said means for addressing and applying voltage signals further including means for applying to a shutter in the addressed row a first voltage signal for causing the ferroelectric liquid crystal to take said first stable orientation, applying to another shutter in the addressed row a second voltage signal for causing the ferroelectric liquid crystal to take said second stable orientation having an opposite direction to that of the first voltage signal, and applying a voltage signal having the same direction as that of the first voltage signal to the shutters in the non-addressed rows of shutters.

44. A liquid crystal apparatus according to claim 43, further comprising a photosensitive member disposed opposite to the light source with the liquid crystal device therebetween so that light from the light source will be selectively transmitted through the liquid crystal device and irradiated onto the photosensitive member.

45. A liquid crystal apparatus according to claim 43, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.

46. A liquid crystal apparatus according to claim 45, wherein said chiral smectic liquid crystal is a chiral smectic C liquid crystal.