Display apparatus and driving method of same

• US 20020093473A1
• Filed: 01/08/2002
• Published: 07/18/2002
• Est. Priority Date: 01/12/2001
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Tanaka, Kyoushi, Nagata, Hisashi
• Granted Patent: US 6,795,066 B2
• Time in Patent Office: Days
• US Class Current: 345/87
• CPC Class Codes: G09G 2310/02 Addressing, scanning or driving the display screen or processing steps related thereto
• CPC Class Codes: G09G 2310/065 Waveforms comprising zero voltage phase or pause
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• 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 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A method of driving a display apparatus including a screen which has pixels arranged in a matrix applies a scanning signal to scanning signal lines connected to the pixels and thus selects each line to scan the screen and also supplies a data signal to those pixels on the selected line via data signal lines, so as to produce a display. Under these conditions, after the screen is scanned twice or more, there is provided a idle period T2 in which all the scanning signal lines are caused to be in a non-scanning state for a period longer than a scanning period T1 in which the screen is scanned once.

Claims

1. A method of driving a display apparatus including a screen which has pixels arranged in a matrix, said method producing a display by applying a scanning signal to scanning signal lines connected to the pixels and thus selecting a line to scan the screen and also by supplying a data signal to those pixels on the selected line via data signal lines,

said method comprising the step of providing, after scanning the screen twice or more, an idle period in which all the scanning signal lines are caused to be in a non-scanning state for a period longer than a time taken to scan the screen once.

2. The method as set forth in claim 1, wherein

the idle period is provided after a. scanning period in which the screen is scanned once is provided twice or more successive times.

3. The method as set forth in claim 1, wherein

in the idle period, there is provided a suspension period in which a circuit irrelevant to display is stopped operating.

4. The method as set forth in claim 1, wherein:

in repeating the step of providing the idle period after a scanning period in which the screen is scanned once is provided twice or more, the idle period is provided after the scanning period is provided an odd number of times; and

a potential of a pixel electrode and/or that of an opposite electrode of each of the pixels is/are controlled so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which alternates from one scanning period to next.

5. The method as set forth in claim 1, wherein:

in repeating the step of providing the idle period after a scanning period in which the screen is scanned once is provided twice or more, the idle period is provided after the scanning period is provided an even number of times; and

a potential of a pixel electrode and/or that of an opposite electrode of each of the pixels is/are controlled so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which remains unchanged throughout the idle period and the scanning period which immediately follows the idle period and alternates from one scanning period to next for each scanning period before a next idle period.

6. The method as set forth in claim 1, wherein

in repeating the step of providing the idle period after a scanning period in which the screen is scanned once is provided twice or more, a potential of a pixel electrode and/or that of an opposite electrode of each of the pixels is/are controlled so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which differs in the idle period and in the scanning period which immediately follows the idle period and remains unchanged throughout scanning periods before a next idle period.

7. The method as set forth in claim 1, wherein

the display apparatus is a liquid crystal display.

8. A method of driving a display apparatus including a screen which has pixels arranged in a matrix, said method producing a display by applying a scanning signal to scanning signal lines connected to the pixels and thus selecting a line to scan the screen and also by supplying a data signal to those pixels on the selected line via data signal lines,

said method comprising the step of providing, when there is no change in an image to be displayed, an idle period in which all the scanning signal lines are caused to be in a non-scanning state for a period longer than a scanning period in which the screen is scanned once after the scanning period and when there has been a change in an image to be displayed, the idle period after the screen is scanned twice or more.

9. The method as set forth in claim 8, wherein

when there has been a change in an image to be displayed, the idle period is provided after the scanning period is provided twice or more successive times.

10. The method as set forth in claim 8, wherein

in the idle period, there is provided a suspension period in which a circuit irrelevant to display is stopped operating.

11. The method as set forth in claim 8, wherein:

in repeating the step of providing the idle period after the scanning period in which the screen is scanned once is provided twice or more, the idle period is provided after the scanning period is provided an odd number of times; and

a potential of a pixel electrode and/or that of an opposite electrode of each of the pixels is/are controlled so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which alternates from one scanning period to next.

12. The method as set forth in claim 8, wherein:

in repeating the step of providing the idle period after the scanning period in which the screen is scanned once is provided twice or more, the idle period is provided after the scanning period is provided an even number of times; and

a potential of a pixel electrode and/or that of an opposite electrode of each of the pixels is/are controlled so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which remains unchanged throughout the idle period and the scanning period which immediately follows the idle period and alternates from one scanning period to next for each scanning period before a next idle period.

13. The method as set forth in claim 8, wherein

in repeating the step of providing the idle period after the scanning period in which the screen is scanned once is provided twice or more, a potential of a pixel electrode and/or that of an opposite electrode of each of the pixels is/are controlled so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which differs in the idle period and in the scanning period which immediately follows the idle period and remains unchanged throughout scanning periods before a next idle period.

14. The method as set forth in claim 8, wherein

the display apparatus is a liquid crystal display.

16. The method as set forth in claim 15, wherein

the screen is scanned twice or more at the predetermined rewrite cycle only when there has been a change in an image to be displayed.

18. The display apparatus as set forth in claim 17, wherein

the control means causes all the scanning signal lines to be in a non-scanning state for a period longer than a scanning period in which the screen is scanned once after the scanning period in which the screen is scanned once is provided twice or more successive times.

19. The display apparatus as set forth in claim 17, wherein

the control means provides a suspension period in which a circuit irrelevant to display is stopped operating in a period in which all the scanning signal lines are caused to be in a non-scanning state for a period longer than a scanning period in which the screen is scanned once.

20. The display apparatus as set forth in claim 17, wherein

in repeating an operation of providing, after a scanning period in which the screen is scanned once is provided twice or more, an idle period in which all the scanning signal lines are caused to be in a non-scanning state for a period longer than the scanning period in which the screen is scanned once, the control means provides the idle period after the scanning period is provided an odd number of times and controls a potential of a pixel electrode and/or that of an opposite electrode of each of the pixels so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which alternates from one scanning period to next.

21. The display apparatus as set forth in claim 17, wherein

in repeating an operation of providing, after a scanning period in which the screen is scanned once is provided twice or more, an idle period in which all the scanning signal lines are caused to be in a non-scanning state for a period longer than the scanning period in which the screen is scanned once, the control means provides the idle period after the scanning period is provided an even number of times and controls a potential of a pixel electrode and/or that of an opposite electrode of each of the pixels so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which remains unchanged throughout the idle period and the scanning period which immediately follows the idle period and alternates from one scanning period to next for each scanning period before a next idle period.

22. The display apparatus as set forth in claim 17, wherein

in repeating an operation of providing, after a scanning period in which the screen is scanned once is provided twice or more, an idle period in which all the scanning signal lines are caused to be in a non-scanning state for a period longer than the scanning period in which the screen is scanned once, the control means controls a potential of a pixel electrode and/or that of an opposite electrode of each of the pixels so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which differs in the idle period and in the scanning period which immediately follows the idle period and remains unchanged throughout scanning periods before a next idle period.

23. The display apparatus as set forth in claim 17, wherein

the display apparatus is a liquid crystal display.

25. The display apparatus as set forth in claim 24, wherein

the control means causes, when there Las been a change in an image to be displayed, all the scanning signal lines to be in a non-scanning state for a period longer than the scanning period in which the screen is scanned once after the scanning period in which the screen is scanned once is provided twice or more successive times.

26. The display apparatus as set forth in claim 24, wherein

the control means provides a suspension period in which a circuit irrelevant to display is stopped operating in a period in which all the scanning signal lines are caused to be in a non-scanning state for a period longer than the scanning period in which the screen is scanned once.

27. The display apparatus as set forth in claim 24, wherein

in repeating an operation of providing, after the scanning period in which the screen is scanned once is provided twice or more, an idle period in which all the scanning signal lines are caused to be in a non-scanning state for a period longer than the scanning period in which the screen is scanned once, the control means provides the idle period after the scanning period is provided an odd number of times and controls a potential of a pixel electrode and/or and that of opposite electrode of each of the pixels so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which alternates from one scanning period to next.

28. The display apparatus as set forth in claim 24, wherein

in repeating an operation of providing, after the scanning period in which the screen is scanned once is provided twice or more, an idle period in which all the scanning signal lines are caused to be in a non-scanning state for a period longer than the scanning period in which the screen is scanned once, the control means provides the idle period after the scanning period is provided an even number of times and controls a potential of a pixel electrode and/or that of an opposite electrode of each of the pixels so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which remains unchanged throughout the idle period and the scanning period which immediately follows the idle period and alternates from one scanning period to next for each scanning period before a next idle period.

29. The display apparatus as set forth in claim 24, wherein

in repeating an operation of providing, after the scanning period in which the screen is scanned once is provided twice or more, an idle period in which all the scanning signal lines are caused to be in a non-scanning state for a period longer than the scanning period in which the screen is scanned once, the control means controls a potential of a pixel electrode and/or that of an opposite electrode of each of the pixels so that the pixel electrode and the opposite electrode develop a potential difference having a polarity which differs in the idle period and in the scanning period which immediately follows the idle period and remains unchanged throughout scanning periods before a next idle period.

30. The display apparatus as set forth in claim 24, wherein

the display apparatus is a liquid crystal display.

15. A method of driving a display apparatus including a screen which has pixels arranged in a matrix, said method producing a display by applying a scanning signal to scanning signal lines connected to the pixels and thus selecting a line to scan the screen at a predetermined rewrite cycle and also by supplying a data signal to those pixels on the selected line via data signal lines,

said method comprising the step of scanning the screen at a rewrite cycle longer than the predetermined rewrite cycle when there is no change in an image to be displayed and at the predetermined rewrite cycle only when there has been a change in an image to be displayed.

17. A display apparatus including a screen which has pixels arranged in a matrix, said apparatus producing a display by applying a scanning signal to scanning signal lines connected to the pixels and thus selecting a line to scan the screen and also by supplying a data signal to those pixels on the selected line via data signal lines,

said apparatus comprising control means for controlling drive of the display apparatus, wherein

the control means causes all the scanning signal lines to be in a non-scanning state for a period longer than a time taken to scan the screen once after the screen is scanned twice or more.

24. A display apparatus including a screen which has pixels arranged in a matrix, said apparatus producing a display by applying a scanning signal to scanning signal lines connected to the pixels and thus selecting a line to scan the screen and also by supplying a data signal to those pixels on the selected line via data signal lines,

said apparatus comprising:

control means for controlling drive of the display apparatus; and

detection means for detecting a change in an image to be displayed, wherein according to a result of the detection by

the detection means, the control means causes, when there is no change in an image to be displayed, all the scanning signal lines to be in a non-scanning state for a period longer than a scanning period in which the screen is scanned once after the screen is scanned once and, when there has been a change in an image to be displayed, all the scanning signal lines to be in a non-scanning state for a period longer than a scanning period in which the screen is scanned once after the screen is scanned twice or more.

31. A display apparatus including a screen which has pixels arranged in a matrix, said apparatus producing a display by applying a scanning signal to scanning signal lines connected to the pixels and thus selecting a line to scan the screen at a predetermined rewrite cycle and also by supplying a data signal to those pixels on the selected line via data signal lines,

said apparatus comprising:

control means for controlling drive of the display apparatus; and

detection means for detecting a change in an image to be displayed,

wherein the control means controls application of the scanning signal to the scanning signal lines according to a result of the detection by the detection means so that the screen is scanned at a rewrite cycle longer than the predetermined rewrite cycle when there is no change in an image to be displayed and at the predetermined rewrite cycle only when there has been a change in an image to be displayed.

32. The display apparatus as set forth in claim 31, wherein

the control means controls application of the scanning signal to the scanning signal line according to a result of the detection by the detection means so that the screen is scanned twice or more at the predetermined rewrite cycle only when there has been a change in an image to be displayed.