Liquid crystal display apparatus

• US 20020047818A1
• Filed: 03/16/2001
• Published: 04/25/2002
• Est. Priority Date: 03/17/2000
• Status: Active Grant

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Yamamoto, Tsunenori, Suzuki, Nobuyuki, Hiyama, Ikuo, Tsumura, Makoto
• Granted Patent: US 6,756,954 B2
• Time in Patent Office: Days
• US Class Current: 345/87
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/103 Detection of image changes, e.g. determination of an index representative of the image change
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A liquid crystal display apparatus has scanning lines, signal lines, active elements, pixel electrodes, common lines and opposed electrodes, arranged on one of a pair of substrates.

The liquid crystal display apparatus further includes opposed electrodes, pixel electrodes corresponding to the opposed electrodes, and a plurality of second scanning lines different from said scanning lines connected through said active elements to the pixel electrodes.

Common lines corresponding to said pixel electrodes are selected between the selection pulse of the scanning line to write the picture signal in said pixel electrode and the selection pulse of said scanning line to display the following image, and a pulse to clear the picture signal applied to said pixel electrode is applied.

Claims

1. A liquid crystal display apparatus comprising:

a pair of substrates, at least one of which is transparent;

a liquid crystal layer interposed between said pair of substrates;

a plurality of scanning electrode lines and a plurality of signal electrode lines formed so as to cross each other in a matrix form;

active elements, each formed proximate to each of the crossing points of said corresponding signal lines and said scanning lines, pixel electrodes connected to said active elements, common lines formed between each of said scanning lines, and opposed electrodes, each formed between said pixel electrodes and each connected to said common lines, are arranged on one of said pair of substrates;

said liquid crystal display apparatus displaying with moving the liquid crystal molecule in the liquid crystal layer by the voltage applied to said pixel electrodes and said opposed electrodes.

further comprising;

a plurality of second active elements connected to said plural opposed electrodes, said plural pixel electrodes corresponding to the opposed electrodes, and second scanning lines different from said scanning lines connected through said active elements to the pixel electrodes, and

wherein common lines corresponding to said pixel electrodes are selected between the selection pulse of the scanning line to write the picture signal in said pixel electrode and the selection pulse of said scanning line to display the following image, and a pulse to clear the picture signal applied to said pixel electrode is applied.

2. A liquid crystal display apparatus according to claim 1, wherein said liquid crystal display apparatus has a normally black characteristic by which the black is displayed in said liquid crystal layer then the voltage is not applied to said pixel electrode and said opposed electrode.

3. A liquid crystal display apparatus according to claim 2,

wherein the scanning line with which said second active element is connected is different from the scanning line with which said first active element is connected, and

wherein said second active element is composed by extending the pixel electrode and the opposed electrode into said different scanning line.

4. A liquid crystal display apparatus according to claim 2 or 3, wherein the period from the selection pulse of the scanning line to write the picture signal in said pixel electrode to the selection pulse of the common line to clear the picture signal applied to said pixel electrode, is less than 50% of the time interval between the scanning line selection pulses.

5. A liquid crystal display apparatus according to claim 2 or 3, wherein the period from the selection pulse of the scanning line to write the picture signal in said pixel electrode to the selection pulse of the common line to clear the picture signal applied to said pixel electrode, is less than 25% of the time interval between the scanning line selection pulses.

6. A liquid crystal display apparatus according to claim 2 or 3, wherein the period from the selection pulse of the scanning line to write the picture signal in said pixel electrode to the selection pulse of the common line to clear the picture signal applied to said pixel electrode, is less than 12.5% of the time interval between the scanning line selection pulses.

7. A liquid crystal display apparatus according to claim 2 or 3, wherein the period from the selection pulse of the scanning line to write the picture signal in said pixel electrode to the selection pulse of the common line to clear the picture signal applied to said pixel electrode, is variable.

8. A liquid crystal display apparatus according to claim 7, wherein the response time of said liquid crystal layer is 10 msec or less.

9. A liquid crystal display apparatus according to claim 7, wherein the response time of said liquid crystal layer is 5 msec or less.

10. A liquid crystal display apparatus according to claim 7, wherein the response time of said liquid crystal layer is 3 msec or less.

11. A liquid crystal display apparatus according to any one of claims 7 to 10, further comprising:

a scanning line drive circuit for supplying the selection pulse to said plural scanning lines,

a signal line drive circuit for supplying the picture signal to said plural signal lines,

a common line drive circuit for supplying the selection pulse to said plural common lines, and

a liquid crystal display controller having a motion picture judgment circuit, for supplying a control signal and a picture signal to the drive circuits,

wherein said liquid crystal display controller judges the pen up speed of the motion picture by using the motion picture judgment circuit, adjusts the period from the selection pulse of said scanning line to the selection pulse of said common line according to the pen up speed, and controls the operation timing of each drive circuit.

16. A liquid crystal display apparatus according to claim 15,

wherein the scanning steps of the plural scanning lines include;

selecting said second active element after selecting said first active element, and

selecting said first active element after selecting said second active element,

17. A liquid crystal display apparatus according to claim 16,

wherein the scanning steps of the plural scanning lines include:

selecting said second active element after selecting said first active element, and

selecting said first active element after selecting said second active element

wherein said two selecting steps are carried out at the same time in connection with different scanning lines.

18. A liquid crystal display apparatus according to claim 17,

wherein two or more steps of selecting said second active element after selecting said first active element are carried out simultaneously.

19. A liquid crystal display apparatus according to claim 17 or 18,

wherein said liquid crystal has a normally black characteristic by which the black is displayed when the voltage is not applied to said pixel electrode and said opposed electrode.

20. A liquid crystal display apparatus according to claim 19,

wherein the average of the time between the step of selecting said second active element after selecting said first active element, and the step of selecting said first active element after selecting said second active element is 50% or less of one screen rewriting cycle.

21. A liquid crystal display apparatus according to claim 19,

wherein the average of the time between the step of selecting said second active element after selecting said first active element, and the step of selecting said first active element after selecting said second active element is 25% or less of one screen rewriting cycle.

22. A liquid crystal display apparatus according to claim 19,

wherein the average of the time between the step of selecting said second active element after selecting said first active element, and the step of selecting said first active element after selecting said second active element is 12.5% or less of one screen rewriting cycle.

23. A liquid crystal display apparatus according to claim 19, wherein the average of the time between the step of selecting said second active element after selecting said first active element, and the step of selecting said first active element after selecting said second active element is variable.

24. A liquid crystal display apparatus according to claim 23,

further comprising:

a scanning line drive circuit for supplying the selection pulse by which said active element is selected to said plural scanning lines,

a signal line drive circuit for supplying a picture signal to said plural signal lines, and

a liquid crystal display controller including a motion picture judgment circuit, for supplying a control signal or a picture signal to said scanning drive circuit and said signal line drive circuit,

wherein said liquid crystal display controller judges the pen up speed of the motion picture by using the motion picture judgment circuit, and controls the timing of each drive circuit by adjusting the period until the next selection pulse of said one is occurred, according to the pen up speed.

26. A liquid crystal display apparatus according to claim 25,

wherein means for controlling the hold of the control signal is connected to the scanning line forming the corresponding pixel, and means for controlling the clear of the control signal is connected with the scanning line other than said scanning line.

27. A liquid crystal display apparatus according to claim 26,

wherein said common line drive circuit transmits a clear pulse which is a control signal for a certain pixel, between a selection pulse which is a control signal for allowing a cirtain pixel to display the image and a selection pulse which is a control signal for transmitting the next display image for said cirtain pixel.

28. A liquid crystal display apparatus according to claim 27,

wherein means for controlling the hold of the control signal applied to the corresponding pixel, means for holding the control signal applied to the corresponding pixel, and means for controlling the clear of the control signal applied to the corresponding pixel.

29. A liquid crystal display apparatus according to claim 1,

wherein means for controlling the hold of the control signal applied to the corresponding pixel, means for holding the control signal applied to the corresponding pixel, and means for controlling the clear of the control signal applied to the corresponding pixel

32. A liquid crystal display apparatus according to claim 25,

wherein Liquid crystal display of claim 25 which has source of light controlled with source of light drive circuit and the source of light drive circuit connected by said liquid crystal display controller.

33. A liquid crystal display apparatus according to claim 4 or 20, wherein the response time of said liquid crystal layer is 10 msec or less.

34. A liquid crystal display apparatus according to claim 5 or 21, wherein the response time of said liquid crystal layer is 5 msec or less.

35. A liquid crystal display apparatus according to claim 1, wherein the response time of said liquid crystal layer is 3 msec or less.

36. A liquid crystal display apparatus according to claim 11 or 24,

further comprising;

an illumination unit for illuminating a pair of substrates between which said liquid crystal layer is positioned,

a drive circuit for driving said illumination unit, and

a liquid crystal display controller having a control circuit for said drive circuit,

wherein said liquid crystal display controller judges the pen up speed of the motion picture by using a motion picture judgment circuit, controls said illumination unit drive circuit according to the speed, and adjusts the brightness of said illumination unit.

37. A liquid crystal display apparatus according to claim 11 or 24,

further comprising;

an illumination unit which can adjust partially luminescence, and

a drive circuit for driving independently each of the luminescence portion of said illumination unit,

wherein said liquid crystal display controller judges the pen up speed of the motion picture by using a motion picture judgment circuit, controls said illumination unit drive circuit according to the speed, and adjusts the brightness and the luminescensce portion of said illumination unit.

12. A liquid crystal display apparatus in which the liquid crystal is sandwitched between a pair of substrates on one of which a plurality of pixel electrodes and a plurality of opposed electrodes;

further comprising

an active matrix substrate, in which said two active elements is connected to every one of said plural pixel electrodes, and a scanning line and a video signal line are connected to one of said active elements, and a scanning line different from said scanning line and a common line connected electrically to the opposed electrode are connected to the other active element.

15. A liquid crystal display apparatus according to any one of claims 12, 13 and 14,

wherein said first and second active elements provided corresponding to said pixel is connected to at least one of said two scanning lines which sandwitch said pixel electrode.

13. A liquid crystal display apparatus in which the liquid crystal is sandwitched between a pair of substrates on one of which a plurality of pixel electrodes and a plurality of opposed electrodes;

further comprising

an active matrix substrate, in which said two active elements is connected to every one of said plural pixel electrodes, and a scanning line and a video signal line are connected to one of said active elements, and a scanning line different from said scanning line and a common line connected electrically to the opposed electrode are connected to the other active element.

14. A liquid crystal display apparatus comprising a pair of substrates, at least one of which is transparent, and a liquid crystal layer interposed between said pair of substrates;

wherein a plurality of pixels and a plurality of common lines are provided on one of said pair of substrates, the plural pixels being composed of a plurality of scanning lines and a plurality of signal lines formed so as to cross with the plural scanning lines, and the common line being bridged across the plural pixels, and

wherein a first active element is arranged in the vicinity of intersection of said plural scanning line and said plural signal lines, a pixel electrode is connected to the first active element, an opposed electrode is arranged so as to connect to said common line, corresponding to the pixel electrode, and a second active element is connected to a scanning line different from the scanning line connected to said first active element.

25. A liquid crystal display apparatus including a pair of substrates, at least one of which is transparent, and a liquid crystal layer interposed between said pair of substrates, for displaying a picture according to the image data input;

further comprising;

a display part provided on one of said pair of substrates,

a liquid crystal display controller for outputting a control signal to display on said display part according to said image data,

a scanning line drive circuit, a signal line drive circuit, and a common line drive circuit, for receiving a control signal output from said liquid crystal display controller and for driving said display part according to the control signal received,

wherein said display part includes;

a plurality of scanning lines connected to said scanning line drive circuit,

a plurality of signal lines connected to said signal line drive circuit, and

a plurality of common lines connected to said common line drive circuit;

wherein each of said plural pixels formed by said plural scanning lines and said plural signal lines includes means for controlling the hold of the control signal applied to the corresponding pixel, means for holding the control signal applied to the corresponding pixel, and means for controlling the clear of the control signal applied to the corresponding pixel.

30. A liquid crystal display apparatus according to claims 25 to 29,

wherein means for controlling the hold of the control signal, and means for controlling the clear of the control signal are active elements.

31. A liquid crystal display apparatus according to claim 30,

wherein said active element is composed of a TFT, and said means for holding said control signal is composed of a capacitor.