DISPLAY AND METHOD OF DRIVING THE DISPLAY CAPABLE OF REDUCING CURRENT AND POWER CONSUMPTION WITHOUT DETERIORATING QUALITY OF DISPLAYED IMAGES

• US 20010040536A1
• Filed: 10/29/1998
• Published: 11/15/2001
• Est. Priority Date: 03/26/1998
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Fujitsu Limited
• Inventors: TANAKA, SHINSUKE, KONDO, NOBUYOSHI, FUJISAKI, TAKASHI, TAKATA, KIYOSHI, OKAYASU, JUNICHI, MATSUI, NAOKI, ASAMI, FUMITAKA, AWATA, YOSHIMASA, ISHIDA, KATSUHIRO, TAJIMA, MASAYA
• Granted Patent: US 6,636,187 B2
• Time in Patent Office: Days
• US Class Current: 345/55
• CPC Class Codes: G09G 2310/0213 controlling the sequence of the scanning lines with respect to the patterns to be displayed, e.g. to save power
• CPC Class Codes: G09G 2310/0227 related to multiple interlacing, i.e. involving more fields than just one odd field and one even field
• CPC Class Codes: G09G 2310/0267 Details of drivers for scan electrodes, other than drivers for liquid crystal, plasma or OLED displays
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2932 Addressed by writing selected cells that are in an OFF state

Abstract

A display has a panel, and first and second electrodes. The first and second electrodes define a matrix of cells on the panel. The second electrodes, which correspond to lines of the cells, are scanned to select the cell lines one by one. The first electrodes are driven to set display data for a selected one of the cell lines. The display also has a sequence setting unit for setting sequences of scanning the second electrodes, and a sequence selection unit for selecting one of the sequences that minimizes the current and power consumption of a first-electrode driver without deteriorating the quality of the displayed images.

Claims

1. A display having a panel, and first and second electrodes;

said first and second electrodes defining a matrix of cells on said panel;

said second electrodes, which correspond to lines of said cells, being scanned to select cell lines one by one;

said first electrodes being driven to set display data for a selected one of said cell lines, wherein said display comprises;

a sequence setting unit for setting sequences of scanning said second electrodes; and

a sequence selection unit for selecting one of the sequences.

2. A display as claimed in

claim 1

, wherein said display further comprises:

a difference detection unit for detecting differences between display data set for said cell lines so that one of the sequences that minimizes the differences is selected.

3. A display as claimed in

claim 1

, wherein said display further comprises:

a difference detection unit for detecting differences between display data set for said cell lines; and

an upper limit setting unit for setting an upper limit so that one of the sequences that suppresses the differences to below the upper limit is selected.

4. A display as claimed in

claim 1

, wherein the sequences are set based on powers of two.

5. A display as claimed in

claim 1

, wherein:

said sequence setting unit divides said second electrodes into blocks and sets sequences of scanning said second electrodes block by block; and

said sequence selection unit selects one of the sequences in each of said blocks.

6. A display as claimed in

claim 1

, wherein said first electrodes are addressing electrodes, and said second electrodes are scan electrodes.

7. A display as claimed in

claim 6

, wherein said display further comprises:

an address driver for driving said addressing electrodes;

a current/power value detection unit for detecting a current or power value of said address driver; and

a sequence changing unit for changing a sequence of scanning said second electrodes to minimize the current or power value.

8. A display as claimed in

claim 7

, wherein said display further comprises:

a current/power value evaluation unit for evaluating a current or power value of said address driver according to display data set for said cell lines so that one of the sequences that minimizes the current or power value is selected.

9. A display as claimed in

claim 7

, wherein said display further comprises:

a reference value setting unit for setting a reference value so that one of the sequences that suppresses the current or power value to below the reference value is selected.

10. A display as claimed in

claim 7

, wherein said display further comprises:

a current/power value evaluation unit for evaluating a current or power value of said address driver according to display data set for said cell lines; and

a reference value setting unit for setting a reference value so that one of the sequences that suppresses the current or power value to below the reference value is selected.

11. A display as claimed in

claim 7

, wherein said display further comprises:

a current/power value evaluation unit for evaluating a current or power value of said address driver beforehand according to display data set for said cell lines; and

a reference value setting unit for setting a reference value so that one of the sequences that suppresses the current or power value to below the reference value is selected.

12. A display as claimed in

claim 1

, wherein said display further comprises:

a display data supplying unit for supplying display data line by line to said first electrodes according to the selected sequence of scanning said second electrodes.

13. A display as claimed in

claim 1

, wherein said display is a plasma display;

a frame of display data is divided into a plurality of sub-frames that are selectively combined to display gradations; and

each of the sub-frames at least includes an addressing period and a sustain period.

14. A display as claimed in

claim 13

, wherein said panel is a three-electrode surface-discharge alternating-current plasma display panel having third electrodes that run in parallel with said second electrodes and applying an alternating voltage to said second and third electrodes to repeat a sustain discharge.

15. A display having a panel, and first and second electrodes;

said first and second electrodes defining a matrix of cells on said panel;

said second electrodes, which correspond to lines of said cells, being scanned to select cell lines one by one;

said first electrodes being driven to set display data for a selected one of said cell lines, wherein said display comprises;

a sequence setting unit for optionally setting a sequence of scanning said second electrodes.

16. A display as claimed in

claim 15

, wherein said display further comprises:

a difference detection unit for detecting differences between display data set for said cell lines so that said second electrodes are scanned in a sequence to minimize the differences.

17. A display as claimed in

claim 15

, wherein said display further comprises:

a difference detection unit for detecting differences between display data set for said cell lines; and

an upper limit setting unit for setting an upper limit so that said second electrodes are scanned in a sequence to suppress the differences to below the upper limit.

18. A display as claimed in

claim 15

, wherein said sequence setting unit divides said second electrodes into blocks and sets a sequence of scanning said second electrodes in each of said blocks.

19. A display as claimed in

claim 15

, wherein said first electrodes are addressing electrodes, and said second electrodes are scan electrodes.

20. A display as claimed in

claim 19

, wherein said display further comprises:

an address driver for driving said addressing electrodes;

a current/power detection unit for detecting a current or power value of said address driver; and

a sequence changing unit for changing a sequence of scanning said second electrodes to minimize the current or power value.

21. A display as claimed in

claim 20

, wherein said display further comprises:

a current/power evaluation unit for evaluating a current or power value of said address driver according to display data set for said cell lines so that said second electrodes are scanned in a sequence to minimize the current or power value.

22. A display as claimed in

claim 20

, wherein said display further comprises:

a reference value setting unit for setting a reference value so that said second electrodes are scanned in a sequence to suppress the current or power value to below the reference value.

23. A display as claimed in

claim 20

, wherein said display further comprises:

a current/power evaluation unit for evaluating a current or power value of said address driver according to display data set for said cell lines; and

a reference value setting unit for setting a reference value so that said second electrodes are scanned in a sequence to suppress the current or power value to below the reference value.

24. A display as claimed in

claim 20

, wherein said display further comprises:

a current/power evaluation unit for evaluating a current or power value of said address driver beforehand according to display data set for said cell lines; and

a reference value setting unit for setting a reference value so that said second electrodes are scanned in a sequence to suppress the current or power value to below the reference value.

25. A display as claimed in

claim 15

, wherein said display further comprises:

a display data supplying unit for supplying display data line by line to said first electrodes according to the determined sequence of scanning said second electrodes.

26. A display as claimed in

claim 15

, wherein said display is a plasma display;

a frame of display data is divided into a plurality of sub-frames that are selectively combined to display gradations; and

each of the sub-frames at least includes an addressing period and a sustain period.

27. A display as claimed in

claim 26

, wherein said panel is a three-electrode surface-discharge alternating-current plasma display panel having third electrodes that run in parallel with said second electrodes and applying an alternating voltage to said second and third electrodes to repeat a sustain discharge.

28. A method of driving a display having a panel, and addressing and scan electrodes, said addressing and scan electrodes defining a matrix of cells on said panel;

said scan electrodes, which correspond to lines of said cells, being scanned to select said cell lines one by one;

said addressing electrodes being driven to set display data for a selected one of said cell lines, wherein said method comprises the steps of;

setting sequences of scanning said scan electrodes;

detecting a current or power value of an address driver for driving said addressing electrodes; and

selecting one of the sequences in accordance with the detected current or power value.

29. A method of driving a display as claimed in

claim 28

, wherein the sequences are set based on powers of two.

30. A method of driving a display having a panel, and addressing and scan electrodes, said addressing and scan electrodes defining a matrix of cells on said panel;

said scan electrodes, which correspond to lines of said cells, being scanned to select said cell lines one by one;

said addressing electrodes being driven to set display data for a selected one of said cell lines, wherein said method comprises the steps of;

detecting a current or power value of an address driver for driving said addressing electrodes; and

optionally setting a sequence of scanning said scan electrodes in accordance with the detected current or power value.

31. A method of driving a display as claimed in

claim 30

, wherein said method further comprises the steps of:

dividing said scan electrodes into blocks; and

setting a sequence of scanning said scan electrodes in each of said blocks.