Method of and apparatus for driving ferroelectric liquid crystal display device

• US 5,289,175 A
• Filed: 09/08/1992
• Issued: 02/22/1994
• Est. Priority Date: 04/03/1989
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kawagishi, Hideyuki
• Primary Examiner(s): Weldon, Ulysses
• Application Number:
  US07/942,130
• Time in Patent Office: 532 Days
• Field of Search: 340/765, 340/784, 340/811, 340/813, 340/814, 359/55, 359/56, 359/84
• US Class Current: 345/97
• 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

Abstract

A method and an apparatus of driving a ferroelectric liquid crystal display device are provided having N scanning electrodes, and M data electrodes arranged in the form of an N×M matrix, N and M being positive integers, and a pixel being formed at each intersection of the scanning electrodes and the data electrodes of the matrix. The method comprises the step of applying a selected scanning signal to a Kth selected scanning electrode in a time period, wherein K is a positive integer and K≦N. A selected data signal is applied to a data electrode in the time period to form a synthetic voltage at a selected pixel, and an auxiliary signal voltage is applied to a (K-A) scanning electrode in the time period, wherein A is a positive integer and 1<A<N.

Claims

1. A method of driving a ferroelectric liquid crystal display device having N scanning electrodes, and M data electrodes arranged in the form of an N×

M matrix, N and M being positive integers, and a pixel being formed at each intersection of the scanning electrodes and the data electrodes of the matrix, said method comprising the steps of;

applying a selected unipolar scanning signal to a Kth selected scanning electrode in a time period, wherein K is a positive integer and K≦

N;

applying a selected data signal to a data electrode in the time period to form a synthetic voltage at a selected pixel;

applying an auxiliary signal voltage polarized opposite to the selected unipolar scanning signal on the basis of a non-selected scanning signal to a (K-A) scanning electrode in the time period, wherein A is a positive integer and 1<

A<

N; and

applying a non-selected scanning signal different from the auxiliary signal voltage to each of the remaining scanning electrodes in the time period.

2. A method according to claim 1, wherein the selected scanning signal has one polarity with respect to the non-selected scanning signal, and wherein the auxiliary signal voltage has the opposite polarity with respect to the non-selected scanning signal.

3. A method according to claim 1, wherein an erasing voltage is applied to the selected pixel on the Kth scanning electrode prior to the application of the selected scanning signal.

4. A method according to claim 1, wherein an erasing voltage is applied to the pixels on the scanning electrodes of the matrix prior to the application of the selected scanning signal voltage.

5. A method according to claim 1, wherein A is equal to 2.

6. A method according to claim 1, further comprising the step of:

applying an additional auxiliary signal to the data electrode, after the application of the selected data signal to the data signal corresponding to the selected

7. An apparatus for driving and controlling a ferroelectric liquid crystal display device having N scanning electrodes and M data electrodes arranged in the form of an N×

M matrix, N and M being positive integers, and a pixel being formed at each intersection of the scanning electrodes of the matrix, said apparatus comprising;

first means applying a selected unipolar scanning signal to a Kth selected scanning electrode in a time period, wherein K is a positive integer and K≦

N;

second means applying a selected data signal to a data electrode in the time period to from a synthetic voltage at a selected pixel;

third means for applying an auxiliary signal voltage polarized opposite to the selected unipolar scanning signal on the basis of a non-selected scanning signal to a (K-A) scanning electrode in the time period, wherein A is a positive integer and 1<

A<

N; and

fourth means for applying a non-selected scanning signal different from the auxiliary signal voltage to each of the remaining scanning electrodes.

8. An apparatus according to claim 7, wherein the selected scanning signal has one plurality with respect to the non-selected scanning signal, and wherein said auxiliary signal voltage has the opposite polarity with respect to the non-selected scanning signal.

9. An apparatus according to claim 7, wherein an erasing voltage is applied to the selected pixel on the Kth scanning electrode prior to the application of the selected scanning signal voltage.

10. An apparatus according to claim 7, wherein an erasing voltage is applied to the pixels on the scanning electrodes of the matrix prior to the application of the selected scanning signal voltages.

11. An apparatus according to claim 7, wherein A is equal to 2.

12. An apparatus according to claim 7, further comprising:

fifth means for applying an additional auxiliary signal to the data electrodes, after the application of the selected data signal to the data signal corresponding to the selected pixel.

13. A method of driving a ferroelectric liquid crystal display device having N scanning electrodes, and M data electrodes arranged in the form of an N×

M matrix, N and M being positive integers, and a pixel being formed at each intersection of the scanning electrodes and the data electrodes of matrix, said method comprising the steps of;

applying a selected unipolar scanning signal of a first frequency to a Kth selected scanning electrode line in a time period, wherein K is a positive integer and K<

N;

applying a selected data signal to a data electrode in the time period to form a synthetic voltage at a selected pixel;

applying an auxiliary signal voltage polarized opposite to the selected unipolar scanning signal on the basis of a non-selected scanning signal of the frequency to a (K-A) scanning electrode in the time period, wherein A is a positive integer and A<

N; and

applying a non-selected scanning signal different from the auxiliary signal voltage to each of the remaining scanning electrodes.

14. A method according to claim 13, wherein the selected scanning signal has one polarity with respect to the non-selected scanning signal, and wherein the auxiliary signal voltage has the opposite polarity with respect to the non-selected scanning signal.

15. A method according to claim 13, wherein an erasing voltage is applied to the selected pixel on the Kth scanning electrode prior to the application of the selected scanning signal.

16. A method according to claim 13, wherein an erasing voltage is applied to the pixels on the scanning electrodes of the matrix prior to the application of the selected scanning signal voltage.

17. A method according to claim 13, wherein A is equal to 1.

18. A method according to claim 13, further comprising the step of:

applying an additional auxiliary signal to the data electrodes, after the application of the selected data signal to the data signal corresponding to the selected pixel.

19. An apparatus for driving and controlling a ferroelectric liquid crystal display device having N scanning electrodes and M data electrodes arranged in the form of an N×

M matrix, N and M being positive integers, and a pixel being formed at each intersection of the scanning electrodes of the matrix, said apparatus comprising;

first means applying a selected unipolar scanning signal of a frequency to a Kth selected scanning electrode in a time period, wherein K is a positive integer and K<

N;

second means applying a selected data signal to a data electrode in the time period to form a synthetic voltage at a selected pixel;

third means for applying an auxiliary signal voltage polarized opposite to the selected unipolar scanning signal on the basis of a non-selected scanning signal of the frequency to a (K-A) scanning electrode in the time period, wherein A is a positive integer and A<

N; and

fourth means for applying a non-selected scanning signal different from the auxiliary signal voltage to each of the remaining electrodes.

20. An apparatus according to claim 19, wherein the selected scanning signal has one polarity with respect to the non-selected scanning signal, and wherein said auxiliary signal voltage has the opposite polarity with respect to the non-selected scanning signal.

21. An apparatus according to claim 19, wherein an erasing voltage is applied to the selected pixel on the Kth scanning electrode prior to the application of the selected scanning signal voltage;

22. An apparatus according to claim 19, wherein an erasing voltage is applied to the pixels on the scanning electrodes of the matrix prior to the application of the selected scanning signal voltage.

23. An apparatus according to claim 19, wherein A is equal to 1.

24. An apparatus according to claim 19, further comprising fifth means for applying an additional auxiliary signal to the data electrodes, after the application of the selected data signal to the data signal corresponding to the selected pixel.