Pixel circuit, display panel, and driving method thereof

• US 8,766,970 B2
• Filed: 10/24/2008
• Issued: 07/01/2014
• Est. Priority Date: 05/05/2008
• Status: Active Grant

• Current Assignee: Optronic Sciences LLC
• Original Assignee: AU Optronics Corporation
• Inventors: Chien, Chih-Yuan, Chen, Chien-Hua, Yang, Chen-Kuo, Huang, Hsueh-Ying
• Primary Examiner(s): NGUYEN, KIMNHUNG T
• Application Number:
  US12/257,397
• Publication Number:
  US 20090273592A1
• Time in Patent Office: 2,076 Days
• Field of Search: 345 87-100, 345211-213
• US Class Current: 345/213
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers

Abstract

A pixel circuit includes a first sub-pixel and a second sub-pixel. The first sub-pixel is coupled to a scan line and a data line, so as to determine whether to be enabled according to a first scan signal transmitted on the scan line, and whether to be driven according to a data signal transmitted on the data line. The second sub-pixel is coupled to the scan line, so as to determine whether to be enabled according to the first scan signal. The data signal is in a first state when the first scan signal is in a pre-charged period. The data signal is in a second state during a time interval after the pre-charged period is over and before the first scan signal enters a turn-on period. Voltage polarities of the first state and the second state are opposite. The pixel design can improve color shift and frame flicker.

Claims

1. A display panel, comprising:

a plurality of scan lines, arranged in parallel in a first direction, for transmitting a plurality of scan signals;

a plurality of data lines, arranged in parallel in a second direction, for transmitting a plurality of data signals, wherein each of the data lines and the scan lines respectively enclose a plurality of pixel regions; and

a pixel array comprising a plurality of pixels arranged in an array and correspondingly disposed in the pixel regions respectively, wherein each pixel comprises a first sub-pixel and a second sub-pixel;

wherein the first sub-pixels and the second sub-pixels of the pixels in an Mth row along a first direction are all coupled to an Mth scan line of the scan lines, at least part of the first sub-pixels and the second sub-pixels of the pixels in an Nth column along a second direction receive the data signal transmitted on an Nth data line of the data lines, where M and N are positive integers, and polarities of each first sub-pixel and each second sub-pixel are opposite.

2. The display panel according to claim 1, wherein the pixels in the N^th column along the second direction are driven according to the data signal transmitted on the N^th data line.

3. The display panel according to claim 2, wherein when the scan signals transmitted on the M^th scan line are in a pre-charged period, at least part of the data signals are in a first state, and during a time interval after the pre-charged period is over and before the scan signal transmitted on the M^th scan line enters a turn-on period, the data signal in the first state in the pre-charged period is switched to a second state, and voltage polarities of the first state and the second state are opposite.

4. The display panel according to claim 1, wherein the first sub-pixels and the second sub-pixels of the pixels in the N^th column along the second direction respectively receive the data signals transmitted on an (N−

1)^th and the N^th data line.

5. The display panel according to claim 4, wherein voltage polarities of the data signals transmitted on neighbouring data lines are opposite, and each time the display panel switches frames, each data signal switches voltage polarity thereof.

6. The display panel according to claim 1, wherein each of the first sub-pixels of the pixels in the N^th column along the second direction comprises:

a first transistor comprising a source coupled to one of the N^th and the (N−

1)^th data lines, and a gate coupled to the scan line;

a first liquid crystal capacitor for grounding a drain of the first transistor; and

a first storage capacitor for coupling the drain of the first transistor to a common voltage line to receive a common voltage.

7. The display panel according to claim 1, wherein each of the second sub-pixels of the pixels in the M^th row along the first direction comprises:

a second transistor comprising a gate coupled to the scan line, and a source coupled to the first sub-pixels of the pixels in an M+1^th row along the first direction;

a second liquid crystal capacitor for grounding a drain of the second transistor; and

a second storage capacitor for coupling the drain of the second transistor to a common voltage line to receive a common voltage.

8. The display panel according to claim 1, further comprising:

a first redundant pixel group comprising a plurality of first redundant pixels, wherein each of the first redundant pixel is correspondingly coupled to the pixels in the first row along the first direction respectively; and

a second redundant pixel group comprising a plurality of second redundant pixels, wherein each of the second redundant pixels is correspondingly coupled to the pixels in the last row along the first direction respectively.

9. The display panel according to claim 1, wherein the first direction and the second direction are perpendicular to each other.

10. A method for driving a plurality of pixels in a display panel, wherein the pixels are arranged in an array, and each pixel comprises a first sub-pixel and a second sub-pixel, the driving method comprising:

controlling polarities of driving voltages of the first sub-pixel and the second sub-pixel to be opposite;

generating a scan signal to enable pixels in an M^th row along a first direction, wherein M is a positive integer;

generating a data signal to drive pixels in an N^th column along a second direction, wherein N is a positive integer;

making the data signal to be in a first state when the scan signal is in a pre-charged period; and

making the data signal to be in a second state during a time interval after the pre-charged period is over and before the scan signal enters a turn-on period, wherein voltage polarities of the first state and the second state are opposite, such that driving voltages of the first sub-pixel and the second sub-pixel of the each pixel are opposite.

11. A method for driving a plurality of pixels in a display panel, wherein the pixels are arranged in an array, and each pixel comprises a first sub-pixel and a second sub-pixel, the driving method comprising:

controlling polarities of driving voltages of the first sub-pixel and the second sub-pixel to be opposite;

generating a scan signal to enable the pixels in an M^th row along a first direction, wherein M is a positive integer;

generating a first data signal to drive a part of the first sub-pixels and the second sub-pixels in an N^th column along a second direction, wherein N is a positive integer;

generating a second data signal to drive remaining first sub-pixels and second sub-pixels in the N^th column along the second direction, wherein the voltage polarities of the first data signal and the second data signal are opposite, such that the driving voltages of the first sub-pixel and the second sub-pixel of the each pixel are opposite; and

switching the polarities of the first data signal and the second data signal in sync when frames are switched.