Liquid crystal display device

• US 6,535,191 B1
• Filed: 03/13/2000
• Issued: 03/18/2003
• Est. Priority Date: 03/29/1999
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Miyachi, Koichi
• Primary Examiner(s): CHANG, KENT WU
• Application Number:
  US09/524,333
• Time in Patent Office: 1,100 Days
• Field of Search: 345/87, 345/94, 345/95, 345/96, 345/99, 345/208, 345/210, 345/89, 345/97
• US Class Current: 345/94
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2310/066 Waveforms comprising a gently increasing or decreasing portion, e.g. ramp
• CPC Class Codes: G09G 3/2007 Display of intermediate tones
• CPC Class Codes: G09G 3/3651 using multistable liquid crystals, e.g. ferroelectric liquid crystals

Abstract

A liquid crystal display device of the present invention includes: a main substrate having a main electrode; a counter substrate having a counter electrode; a liquid crystal material interposed between the main substrate and the counter substrate; and a control section for controlling a response start time of the liquid crystal material by a potential difference between a main electrode voltage that is applied to the main electrode during one frame and a counter electrode voltage that changes in a substantially continuous manner during the one frame, and for changing a transmissivity of the liquid crystal display device based on a magnitude of the main electrode voltage.

Claims

1. A liquid crystal display device comprising:

a main substrate having a main electrode;

a counter substrate having a counter electrode;

a liquid crystal material interposed between the main substrate and the counter substrate; and

a control section for controlling a response start time of the liquid crystal material by a potential difference between a main electrode voltage that is applied to the main electrode during one frame and a counter electrode voltage that changes in a substantially continuous manner during the one frame, and for changing a transmissivity of the liquid crystal display device based on a magnitude of the main electrode voltage.

2. A liquid crystal display device according to claim 1, wherein the control section changes the transmissivity of the liquid crystal display device by changing a direct-current voltage component of the main electrode voltage that is applied to the main electrode.

3. A liquid crystal display device according to claim 1, wherein the control section changes the transmissivity of the liquid crystal display device by changing a direct-current voltage component of the counter electrode voltage that is applied to the counter electrode.

4. A liquid crystal display device according to claim 1, wherein the control section changes the transmissivity of the liquid crystal display device by changing a slope angle of a waveform of the counter electrode voltage with respect to the passage of time.

10. A liquid crystal display device according to claim 1, wherein the one frame includes a period during which at least one of the voltage to be applied to the counter electrode and the voltage to be applied to the main electrode resets the orientation of the liquid crystal material to the initial state.

22. A liquid crystal display device according to claim 1, wherein the liquid crystal material is a ferroelectric liquid crystal material.

26. A liquid crystal display device according to claim 1, wherein the liquid crystal material is an antiferroelectric liquid crystal material.

30. A liquid crystal display device according to claim 1, wherein the liquid crystal material has a liquid crystal mode including two or more stable states.

34. A liquid crystal display device according to claim 1, comprising a light source which is off for a predetermined period within the one frame.

38. A liquid crystal display device according to claim 1, wherein:

the liquid crystal display device includes a red light source, a green light source, and a blue light source, and

field serial color display is performed by sequentially switching from one to another among the light sources for each frame, whereby a single color image is obtained from a plurality of frames.

5. A liquid crystal display device comprising:

a TFT substrate having thin film transistors arranged in a matrix;

a counter substrate having a transparent electrode;

a liquid crystal material interposed between the TFT substrate and the counter substrate; and

a control section for applying a voltage that changes in a substantially continuous manner to a storage capacitor line during a period within one frame, thereby writing a drain voltage in a drain electrode during the one frame,

wherein a response start time of the liquid crystal material is determined by a magnitude of the drain voltage, and

a transmissivity of the liquid crystal display device is determined by a potential difference between a potential of the storage capacitor line and a potential of the drain electrode.

6. A liquid crystal display device according to claim 5, wherein the storage capacitor line is connected to a power supply which can be controlled independently of the power supply for applying the voltage to the counter substrate.

7. A liquid crystal display device according to claim 5, wherein:

an odd-numbered line storage capacitor line to be connected to pixels of odd-numbered lines is connected to a first power supply;

an even-numbered line storage capacitor line to be connected to pixels of even-numbered lines is connected to a second power supply; and

the first power supply is different from the second power supply.

8. A liquid crystal display device according to claim 5, wherein the one frame includes a period during which a voltage for resetting an orientation of the liquid crystal material to the initial state is applied to the storage capacitor line.

9. A liquid crystal display device according to claim 5, wherein the control section applies the voltage for resetting the orientation of the liquid crystal material to the initial state to the liquid crystal material through a source line during the one frame.

11. A liquid crystal display device according to claim 5, wherein, during the one frame, after a signal has been written in the thin film transistor element, the voltage that changes in a substantially continuous manner is applied to the storage capacitor line.

12. A liquid crystal display device according to claim 5, wherein the one frame includes a period during which a signal is written in the thin film transistor element, a period during which a voltage to be applied to the storage capacitor line changes in a substantially continuous manner, and a period during which the orientation of the liquid crystal material is reset to the initial state.

23. A liquid crystal display device according to claim 5, wherein the liquid crystal material is a ferroelectric liquid crystal material.

27. A liquid crystal display device according to claim 5, wherein the liquid crystal material is an antiferroelectric liquid crystal material.

31. A liquid crystal display device according to claim 5, wherein the liquid crystal material has a liquid crystal mode including two or more stable states.

35. A liquid crystal display device according to claim 5, comprising a light source which is off for a predetermined period within the one frame.

39. A liquid crystal display device according to claim 5, wherein:

the liquid crystal display device includes a red light source, a green light source, and a blue light source, and

field serial color display is performed by sequentially switching from one to another among the light sources for each frame, whereby a single color image is obtained from a plurality of frames.

42. A liquid crystal display device according to claim 5,

wherein the control section controls a waveform of a voltage to be applied to the storage capacitor line, thereby adjusting at least one gray scale property of the liquid crystal display device.

45. A liquid crystal display device according to claim 5,

wherein the control section adjusts a source signal voltage to be written corresponding to a gray scale signal, thereby adjusting at least one gray scale property of the liquid crystal display device.

13. A liquid crystal display device comprising:

a main substrate having a main electrode;

a counter substrate having a counter electrode;

a liquid crystal material interposed between the main substrate and the counter substrate; and

a control section for applying a voltage that changes in a substantially continuous manner to the liquid crystal material for a predetermined period within one frame,

wherein a response start time of the liquid crystal material and a transmissivity of the liquid crystal display device are changed by changing an amplitude of the voltage.

15. A liquid crystal display device according to claim 13, wherein:

the control section includes a first power supply for applying a voltage to the liquid crystal display material through an odd-numbered line and a second power supply for applying a voltage to the liquid crystal display material through an even-numbered line; and

the first power supply is different from the second power supply.

16. A liquid crystal display device according to claim 13, wherein the one frame includes a period during which a voltage for resetting an orientation of the liquid crystal material to an initial state is applied to the liquid crystal material.

17. A liquid crystal display device according to claim 13, wherein the one frame includes a period during which a voltage for resetting an orientation of the liquid crystal material to an initial state is applied to the element.

24. A liquid crystal display device according to claim 13, wherein the liquid crystal material is a ferroelectric liquid crystal material.

28. A liquid crystal display device according to claim 13, wherein the liquid crystal material is an antiferroelectric liquid crystal material.

32. A liquid crystal display device according to claim 13, wherein the liquid crystal material has a liquid crystal mode including two or more stable states.

36. A liquid crystal display device according to claim 13, comprising a light source which is off for a predetermined period within the one frame.

40. A liquid crystal display device according to claim 13, wherein:

the liquid crystal display device includes a red light source, a green light source, and a blue light source, and

field serial color display is performed by sequentially switching from one to another among the light sources for each frame, whereby a single color image is obtained from a plurality of frames.

43. A liquid crystal display device according to claim 13,

wherein the control section controls a waveform of a voltage to be applied to the liquid crystal material, thereby adjusting at least one gray scale property of the liquid crystal display device.

14. A liquid crystal display device comprising:

a TFT substrate having thin film transistors arranged in a matrix;

a counter substrate having a transparent electrode;

a liquid crystal material interposed between the TFT substrate and the counter substrate;

an element having a resistance value that changes in accordance with a voltage applied to a memory capacitor of a pixel; and

a control section for applying a voltage that changes in a substantially continuous manner to the element during a period within one frame,

wherein the liquid crystal material is connected in series to the element, and

a response start time of the liquid crystal material and a transmissivity of the liquid crystal display device are changed by changing an amplitude of the voltage that changes in a substantially continuous manner.

18. A liquid crystal display device according to claim 14, wherein the one frame includes a period during which a voltage for resetting an orientation of the liquid crystal material to an initial state is applied to the element.

19. A liquid crystal display device according to claim 14, wherein the control section applies a voltage for resetting to an initial state an orientation of the liquid crystal material to the liquid crystal material through a source line.

20. A liquid crystal display device according to claim 14, wherein, during the one frame, after a signal has been written in the thin film transistor element, the voltage that changes in a substantially continuous manner is applied to the element.

21. A liquid crystal display device according to claim 14, wherein the one frame includes a first period during which a signal is written in the thin film transistor element, a second period during which a voltage to be applied to the element changes in a substantially continuous manner, and a third period during which the orientation of the liquid crystal material is reset to the initial state.

25. A liquid crystal display device according to claim 14, wherein the liquid crystal material is a ferroelectric liquid crystal material.

29. A liquid crystal display device according to claim 14, wherein the liquid crystal material is an antiferroelectric liquid crystal material.

33. A liquid crystal display device according to claim 14, wherein the liquid crystal material has a liquid crystal mode including two or more stable states.

37. A liquid crystal display device according to claim 14, comprising a light source which is off for a predetermined period within the one frame.

41. A liquid crystal display device according to claim 14, wherein:

the liquid crystal display device includes a red light source, a green light source, and a blue light source, and

field serial color display is performed by sequentially switching from one to another among the light sources for each frame, whereby a single color image is obtained from a plurality of frames.

44. A liquid crystal display device according to claim 14,

wherein the control section controls a waveform of a voltage to be applied to the element, thereby adjusting at least one gray scale property of the liquid crystal display device.

46. A liquid crystal display device according to claim 14,

wherein the control section adjusts a source signal voltage that is to be written in the element and that corresponds to a gray scale signal, thereby adjusting at least one gray scale property of the liquid crystal display device.