Driving process for liquid crystal display

• US 6,819,311 B2
• Filed: 12/07/2000
• Issued: 11/16/2004
• Est. Priority Date: 12/10/1999
• Status: Active Grant

• Current Assignee: Gold Charm Limited (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Nose, Takashi, Hayama, Hiroshi
• Primary Examiner(s): Liang, Regina
• Assistant Examiner(s): Dinh, Duc Q
• Application Number:
  US09/730,610
• Publication Number:
  US 20010003448A1
• Time in Patent Office: 1,440 Days
• Field of Search: 345/87, 345/90, 345/89, 345/94-96, 345/98-99, 345/209, 345/214
• US Class Current: 345/100
• CPC Class Codes: G09G 2310/02 Addressing, scanning or driving the display screen or processing steps related thereto
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• 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 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3677 suitable for active matrices only

Abstract

The provision of a liquid crystal display driving process which prevents the appearance of motion blur without any increase in circuit size or any reduction in panel numerical aperture. A driving process for a liquid crystal display in which a plurality of scanning lines 2 and a plurality of signal lines 3 are disposed in a grid like arrangement, and display of an image corresponding with image data is performed by selecting any one of the scanning lines 2 at one time, and altering the state of a liquid crystal via the signal line 3, wherein an image data selection period t1 and a black display selection period t2 are set within a time frame shorter than the time necessary for scanning any one of the aforementioned scanning lines 2, and an image corresponding with the aforementioned image data is displayed via the aforementioned signal line 3 during the image data selection period t1, and a monochromatic image is displayed via the aforementioned signal line 3 during the black display selection period t2.

Claims

1. A driving process for a liquid crystal display in which a plurality of scanning lines and a plurality of signal lines are disposed in a grid arrangement, and display of an image corresponding with image data is performed by selecting any one of said scanning lines at one time, and altering a state of a liquid crystal via a signal line, the driving process comprising:

setting a first scanning period and a second scanning period within a time frame for scanning any one of said scanning lines;

displaying an image corresponding with said image data via said signal line during said first scanning period of said time frame on a first of said scanning lines;

displaying a monochromatic image via said signal line during said second scanning period on a second of said scanning lines within said time frame, wherein said first and second scanning lines are separated by a predetermined number of scanning lines; and

applying a varying voltage to a common electrode to allow the voltage of said signal line to be reduced, wherein the varying voltage is applied to the common electrode for one scanning period for displaying image data and another period for displaying a black image.

2. The driving process of claim 1, wherein said monochromatic image is sequentially displayed across a predetermined number of consecutive scanning lines.

3. The driving process of claim 1, wherein signals relating to an image corresponding with said image data and a monochromatic image are output alternately to said signal line, and said signal relating to an image corresponding with said image data is output with an inversion in polarity at every said first scanning period, and a signal relating to said monochromatic image is output with an inversion in polarity at every said second scanning period.

4. The driving process of claim 1, wherein said monochromatic image comprises a black image.

5. The driving process of claim 4, wherein said liquid crystal is constructed so that a display state thereof is white when no voltage is applied thereto and gradually alters to a black display state in accordance with an applied voltage, said liquid crystal is positioned between said pixel electrode and said common electrode, and a voltage applied between said pixel electrode and said common electrode when displaying a black image during said second scanning period is greater than a voltage applied between said pixel electrode and said common electrode when producing a display during said first scanning period.

6. The driving process of claim 5, further comprising increasing a voltage applied to said pixel electrode via said signal line.

7. The driving process of to claim 5, further comprising applying a voltage to said pixel electrode via said signal line.

8. The driving process of claim 1, wherein said scanning lines are connected to a plurality of scanning line driving circuits,

wherein two of said plurality of scanning line driving circuits are selected for scanning,

wherein one of said two scanning line driving circuits scans scanning lines, which are connected to said one scanning line driving circuit during said first scanning period, and

wherein the other of said two scanning line driving circuits scans scanning lines which are connected to said other scanning line driving circuit during said second scanning period.

9. The process of claim 1, wherein said scanning lines are connected to at least four scanning line driving circuits, wherein scanning lines are scanned in sequence by two of said four scanning line driving circuits during one of said first and second scanning periods and by the other two of said four scanning line driving circuits during the other of said first and second scanning periods.

10. The process of claim 1, wherein the monochromatic image comprises a black image that is displayed for a short period of time.

11. The process of claim 1, wherein the liquid crystal display is driven by a low voltage.

12. The process of claim 1, wherein the liquid crystal display rapidly displays the monochromatic image.

13. The process of claim 1, wherein the varying voltage is applied during at least one of said first scanning period and said second scanning period.

14. The process of claim 1, wherein said monochromatic image is processed during the period of time said monochromatic image display is selected without increasing the range of the voltage to said signal line.

15. The process of claim 1, wherein said displaying of said monochromatic image is completed even when a monochromatic image portion of said display is reduced.

16. A driving process for a liquid crystal display in which a plurality of scanning lines and a plurality of signal lines are disposed in a grid arrangement, and display of an image corresponding with image data is performed by selecting any one of said scanning lines at one time, and altering a state of a liquid crystal via a signal line, the driving process comprising:

setting a first scanning period and a second scanning period within a time frame for scanning any one of said scanning lines;

displaying an image corresponding with said image data via said signal line during said first scanning period; and

displaying a monochromatic image via said signal line during said second scanning period, wherein said first scanning period and said second scanning period are separated by a predetermined time on at least one of said plurality of scanning lines, wherein said displaying said image and displaying said monochromatic image comprise applying a varying voltage to a common electrode to allow the voltage of said signal line to be reduced, wherein the varying voltage is applied to the common electrode for one scanning period for displaying image data and another period for displaying a black image.

17. The process of claim 16, wherein said monochromatic image is sequentially displayed across a predetermined number of consecutive scanning lines.

18. The process of claim 16, wherein signals relating to an image corresponding with said image data and a monochromatic image are output alternately to said signal line, and said signal relating to an image corresponding with said image data is output with an inversion in polarity between each said first scanning period, and a signal relating to said monochromatic image is output with an inversion in polarity between each said second scanning period.

19. The process of claim 16, wherein said monochromatic image comprises a black image.

20. The process of claim 19, wherein said liquid crystal is constructed so that a display state thereof is white when no voltage is applied and gradually alters to a black display state in accordance with an applied voltage, said liquid crystal being positioned between a pixel electrode and a common electrode, and a voltage applied between said pixel electrode and said common electrode when displaying a black image during said second scanning period is greater than a voltage applied between said pixel electrode and said common electrode when producing a black display during said first scanning period.

21. The process of claim 20, wherein a voltage applied between said pixel electrode and said common electrode is made variable by applying a varying voltage to said pixel electrode via said signal line.

22. A driving process for a liquid crystal display in which a plurality of scanning lines and a plurality of signal lines are disposed in a grid arrangement, and display of an image corresponding with image data is performed by selecting any one of said scanning lines at one time, and altering a state of a liquid crystal via a signal line, the driving process comprising:

setting a first scanning period and a second scanning period within a time frame for scanning any one of said scanning lines;

displaying an image corresponding with said image data via said signal line during said first scanning period of said time frame on a first of said scanning lines;

displaying a monochromatic image via said signal line during said second scanning period on a second of said scanning lines within said time frame, wherein said first and second scanning lines are separated by a predetermined number of scanning lines; and

applying a varying voltage to a common electrode, wherein the varying voltage is applied to the common electrode for one scanning period for displaying image data and another period for displaying a black image.