Display apparatus and drive control method thereof

• US 7,714,833 B2
• Filed: 09/07/2005
• Issued: 05/11/2010
• Est. Priority Date: 09/09/2004
• Status: Expired due to Fees

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Kamio, Tomomi
• Primary Examiner(s): Mengistu, Amare
• Assistant Examiner(s): SHARIFI-TAFRESHI, KOOSHA
• Application Number:
  US11/220,862
• Publication Number:
  US 20060050011A1
• Time in Patent Office: 1,707 Days
• Field of Search: 345 11- 13, 345 87-103, 345/30, 345/211, 345/204, 349/142, 349150-152
• US Class Current: 345/103
• 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 wherein signal lines of a first active-matrix type display panel are electrically connected to signal lines of a second active-matrix type display panel, the apparatus comprising:

a control section which, when controlling the first active-matrix type display panel to be put into a display state and the second active-matrix type display panel to be put into a non-display state, performs refresh operations of the second active-matrix type display panel every predetermined number of frames and controls a frequency of voltage switching at a common electrode of the first active-matrix type display panel in a period corresponding to the predetermined number of frames to become less than a frequency of voltage switching when putting both of the first active-matrix type display panel and the second active-matrix type display panel into display states.

2. The display apparatus according to claim 1, wherein the control section controls a first frame, in which a refresh period to perform a refresh operation of the second active-matrix type display panel within a frame period thereof is provided, to be inserted in a plurality of second frames in which the refresh period is not provided within a frame period thereof.

3. The display apparatus according to claim 2, wherein the control section controls the second active-matrix type display panel so as to perform scanning of scan lines during a period corresponding to the first frame and stop scanning of scan lines during a period corresponding to the second frames.

4. The display apparatus according to claim 2, wherein the control section carries out a refresh operation of the second active-matrix type display panel by performing scanning of scan lines during a period corresponding to the first frame to the second-active-matrix type display panel.

5. The display apparatus according to claim 2, wherein the control section controls each selection time in each scan line of the first active-matrix type display panel so that a selection time in the second frame becomes longer than a selection time in the first frame.

6. The display apparatus according to claim 5, wherein the control section performs control so that a voltage switching timing at the common electrode of the first active-matrix type display panel synchronizes with scanning of scan lines of the first active-matrix type display panel.

7. The display apparatus according to claim 3, wherein the control section controls the second active-matrix type display panel so that during periods corresponding to the first frame, the selection period of each scan line becomes equal.

8. The display apparatus according to claim 7, wherein the control section performs control so that between first frames that are adjacent in time a polarity of the common electrode in the second active-matrix type display panel differs.

9. The display apparatus according to claim 3, wherein the control section controls the second active-matrix type display panel so that during periods corresponding to the first frame a selection period of any one of scan lines becomes equal to a selection period of another scan line.

10. The display apparatus according to claim 3, wherein the control section controls the second active-matrix type display panel so that during a period corresponding to the first frame each selection period of odd number scan lines becomes equal and does not overlap with a selection period of even number scan lines.

11. The display apparatus according to claim 1, wherein the control section performs control so that a voltage switching timing at the common electrode of the second active-matrix type display panel synchronizes with scanning of scan lines of the second active-matrix type display panel.

12. An electronic device having a display apparatus wherein signal lines of a first active-matrix type display panel are electrically connected to signal lines of a second active-matrix type display panel, the electronic device comprising:

a control section which, when controlling the first active-matrix type display panel to be put into a display state and the second active-matrix type display panel to be put into a non-display state, performs refresh operations of the second active-matrix type display panel every predetermined number of frames and controls a frequency of voltage switching at a common electrode of the first active-matrix type display panel in a period corresponding to the predetermined number of frames to become less than a frequency of voltage switching when putting both of the first active-matrix type display panel and the second active-matrix type display panel into display states.

13. The electronic device according to claim 12, wherein the electronic device is a cellular phone comprising as a main screen one of the first active-matrix type display panel and the second active-matrix type display panel, and as a sub-screen the other of the first active-matrix type display panel and the second active-matrix display panel.

14. A drive method for a display apparatus, wherein signal lines of a first active-matrix type display panel are electrically connected to signal lines of a second active-matrix type display panel, the drive method comprising:

when controlling the first active-matrix type display panel to be put into a display state and the second active-matrix type display panel to be put into a non-display state, performing refresh operations of the second active-matrix type display panel every predetermined number of frames and controlling a frequency of voltage switching at a common electrode of the first active-matrix type display panel in a period corresponding to the predetermined number of frames to become less than a frequency of voltage switching when putting both of the first active-matrix type display panel and the second active-matrix type display panel into display states.

15. The drive method according to claim 14, wherein further comprising:

controlling a first frame, in which a refresh period to perform a refresh operation of the second active-matrix type display panel within a frame period thereof is provided, to be inserted in a plurality of second frames in which the refresh period is not provided within a frame period thereof.