Display apparatus and drive control method thereof

• US 20060050011A1
• Filed: 09/07/2005
• Published: 03/09/2006
• Est. Priority Date: 09/09/2004
• Status: Active Grant

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Kamio, Tomomi
• Granted Patent: US 7,714,833 B2
• Time in Patent Office: Days
• US Class Current: 345/1.100
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3666 with the matrix divided into sections

Abstract

A display apparatus which displays an image corresponding to a display signal comprising a plurality of display panels which have, respectively, a plurality of display pixels; and•• a control means which sets at least one display panel among the plurality of display panels in a display state and sets the plurality of display panels other than the at least one display panel in a non-display state, drives the display panel which has been set in the display state based on the display signal for each of a plurality of constant frame periods, and drives the display panel which has been set in the display state based on the display signal and performs a refresh operation of the display panel which has been set in the non-display state only in a specific frame period from the plurality of constant frame periods.

Claims

1. A display apparatus which displays an image corresponding to a display signal, comprising at least:

a plurality of display panels which have, respectively, a plurality of display pixels; and

a control means which sets at least one display panel among the plurality of display panels in a display state and sets the plurality of display panels other than the at least one display panel in a non-display state, drives the display panel which has been set in the display state based on the display signal for each of a plurality of constant frame periods, and drives the display panel which has been set in the display state based on the display signal and performs a refresh operation of the display panel which has been set in the non-display state only in a specific frame period from the plurality of constant frame periods.

2. The display apparatus according to claim 1, wherein the display apparatus has two display panels;

and

the control means sets one of the two display panels in the display state and sets the other of the two display panels in the non-display state.

3. The display apparatus according to claim 1, wherein each of the display panels have a plurality of scanning lines and a plurality of signal lines, the plurality of display pixels have a pixel electrode arranged in matrix form near each intersection point of the plurality of scanning lines and the plurality of signal lines, and a common electrode arranged in an opposed position to each of the pixel electrodes;

the display apparatus further comprising;

a scan driver which applies a scanning signal sequentially to each of the plurality of scanning lines of each of the display panels;

a signal driver which applies a display signal voltage corresponding to the display signal to the plurality of signal lines of each of the display panels; and

a common electrode driver which applies a common electrode signal that reverses polarity in a predetermined cycle to the common electrode of each of the display panels.

4. The display apparatus according to claim 3, wherein the control means controls each applied timing of the scanning signal applied to each of the scanning lines of the display panel which has been set in the display state by the scan driver;

the common electrode signal applied to the common electrode of the display panel which has been set in the display state by the common electrode driver and performs polarity reversals during each of the plurality of constant frame periods.

5. The display apparatus according to claim 3, wherein at least a portion of the plurality of signal lines are mutually wired together between each of the display panels.

6. The display apparatus according to claim 3, wherein the signal driver applies the display signal voltage to the plurality of signal lines of the display panel which has been set in the non-display state to change the display panel to a white display state during a period which performs the refresh operation in the specific frame period in order to perform the refresh operation.

7. The display apparatus according to claim 3, wherein the control means applies the scanning signal simultaneously to all the scanning lines of the display panel which has been set in the non-display state by the scan side driver means during a period in the specific frame period which performs the refresh operation in order to perform the refresh operation.

8. The display apparatus according to claim 3, wherein the control means applies the scanning signal simultaneously to each of a predetermined number of scanning lines which are divided into plural segments of the plurality of scanning lines of the display panel which has been set in the non-display state by the scan driver during a period in the specific frame period which performs the refresh operation.

9. The display apparatus according to claim 8, wherein the predetermined number of scanning lines to which the scanning signal is applied simultaneously in the refresh operation, the plurality of scanning lines of the display panel which has been set in the non-display state are divided into two segments of even lines and odd lines.

10. The display apparatus according to claim 3, wherein the control means controls the common electrode driver to perform polarity reversals of the common electrode signal to the display panel which has been set in the non-display state in each of the specific frame period which performs the refresh operation.

11. The display apparatus according to claim 3, wherein the control means lengthens a cycle of polarity reversals of the common electrode signal to the display panel which has been set in the display state in a plurality of frame periods that do not perform the refresh operation of the display panel which has been set in the non-display state more than a cycle of polarity reversals of the common electrode signal to the display panel which has been set in the display state in the specific frame period which performs the refresh operation.

12. The display apparatus according to claim 3, wherein the control means controls to set the cycle of polarity reversals of the common electrode signal to the display panel which has been set in the display state as the same value in the plurality of frame periods that do not perform the refresh operation and in the specific frame period which performs the refresh operation of the display panel which has been set in the non-display state.

13. An electronic apparatus having a display apparatus which displays an image corresponding to a display signal, comprising at least:

two display panels which have a plurality of display pixels; and

a control means which sets one of the two display panels in a display state and sets the other of the two display panels in a non-display state, drives the display panel which has been set in the display state based on the display signal for each of a plurality of constant frame periods, and drives the display panel which has been set in the display state based on the display signal and performs a refresh operation of the display panel which has been set in the non-display state only in a specific frame period from the plurality of constant frame periods.

14. The electronic apparatus according to claim 13 is a cellular phone which uses one of the two display panels as a main screen and the other of the two display panels as a sub-screen.

15. The electronic apparatus according to claim 13, wherein each of the display panels is a liquid crystal display having a plurality of scanning lines and a plurality of signal lines, the plurality of display pixels have a pixel electrode arranged in matrix form near each intersection point of the plurality of scanning lines and the plurality of signal lines, and a common electrode arranged in an opposed position to each of the pixel electrodes;

the display apparatus further comprising;

a scan driver which applies a scanning signal sequentially to each of the plurality of scanning lines of each of the display panels;

a signal driver which applies a display signal voltage corresponding to the display signal to the plurality of signal lines of each of the display panels; and

a common electrode driver which applies a common electrode signal that reverses polarity in a predetermined cycle to the common electrode of each of the display panels.

16. The electronic apparatus according to claim 15, wherein the control means controls each applied timing of the scanning signal applied to each of the scanning lines of the display panel which has been set in the display state by the scan driver;

the common electrode signal applied to the common electrode of the display panel which has been set in the display state by the common electrode driver and performs polarity reversals during each of the plurality of constant frame periods.

17. The electronic apparatus according to claim 15, wherein•

•

at least a portion of the plurality of signal lines are mutually wired together between each of the display panels.

18. The electronic apparatus according to claim 15, wherein the signal driver applies the display signal voltage to the plurality of signal lines of the display panel which has been set in the non-display state to change the display panel to a white display state during a period which performs the refresh operation in the specific frame period in order to perform the refresh operation.

19. The electronic apparatus according to claim 15, wherein the control means applies the scanning signal simultaneously to all the scanning lines of the display panel which has been set in the non-display state by the scan driver during a period in the specific frame period which performs the refresh operation in order to perform the refresh operation.

20. The electronic apparatus according to claim 15, wherein the control means applies the scanning signal simultaneously to each of a predetermined number of scanning lines which are divided into plural segments of the plurality of scanning lines of the display panel which has been set in the non-display state by the scan driver during a period in the specific frame period which performs the refresh operation.

21. The electronic apparatus according to claim 20, wherein the predetermined number of scanning lines to which the scanning signal is applied simultaneously in the refresh operation, the plurality of scanning lines of the display panel which has been set in the non-display state are divided into two segments of even lines and odd lines.

22. The electronic apparatus according to claim 15, wherein the control means controls the common electrode driver to perform polarity reversals of the common electrode signal to the display panel which has been set in the non-display state in each of the specific frame period which performs the refresh operation.

23. The electronic apparatus according to claim 15, wherein the control means lengthens a cycle of polarity reversals of the common electrode signal to the display panel which has been set in the display state in a plurality of frame periods that do not perform the refresh operation of the display panel which has been set in the non-display state more than a cycle of polarity reversals of the common electrode signal to the display panel which has been set in the display state in the specific frame period which performs the refresh operation.

24. The electronic apparatus according to claim 15, wherein the control means controls the cycle of polarity reversals of the common electrode signal to the display panel which has been set in the display state as the same value in the plurality of frame periods that do not perform the refresh operation and the specific frame period which performs the refresh operation of the display panel which has been set in the non-display state.

25. A drive control method for a display apparatus which performs an image display comprising a plurality of display panels having a plurality of scanning lines and a plurality of signal lines, a plurality of display pixels which have a pixel electrode arranged in matrix form near each intersection point of the plurality of scanning lines and the plurality of signal lines, and a common electrode arranged in an opposed position to each of the pixel electrodes, comprising at least:

a process for setting at least one display panel among the plurality of display panels in a display state and setting the plurality of display panels other than the at least one display panel in a non-display state;

a process for driving the display panel which has been set in the display state for each of a plurality of constant frame periods; and

a process for performing a refresh operation of the display panel which has been set in the non-display state only in a specific frame period from the plurality of constant frame periods.

26. The drive control method according to claim 25, wherein the refresh operation of the display panel which has been set in the non-display state, comprises:

a process for applying a display signal voltage to the plurality of signal lines of the display panel which has been set in the non-display state to change the display panel to a white display state.

27. The drive control method according to claim 25, wherein the refresh operation of the display panel which has been set in a non-display state, further comprises:

a process for applying the scanning signal simultaneously to the plurality of scanning lines of the display panel which has been set in the non-display state.

28. The drive control method according to claim 25, wherein the refresh operation of the display panel which has been set in a non-display state, further comprises:

a process for applying the scanning signal simultaneously to each of a predetermined number of scanning lines which are divided into plural segments of the plurality of scanning lines of the display panel which has been set in the non-display state.

29. The drive control method according to claim 25, further comprises a process for performing polarity reversals of the common electrode signal applied to the common electrode of the display panel which has been set in the non-display state in each of the specific frame period which performs the refresh operation.

30. The drive control method according to claim 25, further comprises:

a process for lengthening a cycle of polarity reversals of the common electrode signal applied to the common electrode of the display panel which has been set in the display state in the plurality of constant frame periods that do not perform the refresh operation of the display panel which has been set in the non-display state more than a cycle of polarity reversals of the common electrode signal applied to the common electrode of the display panel which has been set in the display state in the specific frame period which performs the refresh operation.

31. The drive control method according to claim 25, further comprises:

a process for setting the cycle of polarity reversals of the common electrode signal applied to the common electrode of the display panel which has been set in the display state as the same value in the plurality of frame periods that do not perform the refresh operation and in the specific frame period which performs the refresh operation of the display panel which has been set in the non-display state.