Method and system for driving an active matrix display device

• US 20070120801A1
• Filed: 11/29/2006
• Published: 05/31/2007
• Est. Priority Date: 11/30/2005
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Hsieh, Yao-Jen, Ho, Yu-Hsi, Su, Fang-Yu, Chang, Wen-Chieh
• Granted Patent: US 8,749,465 B2
• Time in Patent Office: Days
• US Class Current: 345/98
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 3/3666 with the matrix divided into sections
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: G09G 3/3688 suitable for active matrices only

Abstract

A method for driving an active matrix display wherein each image frame is divided into a number of displayed frame portions, each of which is followed by a darker frame portion. The image data in the darker frame portion is removed so as to allow the pixel luminance to diminish. The temporal separation between the displayed frame portion and the following darker frame portion is smaller than a frame time. In a display where the lines are driven repetitively for forming the display image in a plurality of frame times, the image data provided to a pixel, after the luminance in that pixel changes from low to high, is adjusted so that the brightness of the pixel in the preceding frame times appear higher or not lower than that in following frames times.

Claims

1. A method for driving an active matrix display having a plurality of pixels, said method comprising:

providing image data to the pixels for producing luminance in the pixels based on the provided data in a first period of a frame time, and

removing at least part of the provided data from the pixels after the first period so as to reduce the luminance in said pixels in a second period following the first period, wherein the sum of the first period and the second period is less than or substantially equal to one frame time.

2. The method of claim 1, wherein the pixels are arranged in a plurality of lines and the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a following second group of frame times, and wherein a sum of the luminance in the first period and the luminance in the second period yields a total luminance, and the total luminance in said pixels in the first group is lower than the total luminance in said pixels in the second group, said method further comprising:

adjusting the image data provided to said pixels in the first group of frame times so as to increase the total luminance in said pixels in the first group of frame times.

3. The method of claim 2, wherein image data is so adjusted such that the total luminance in said pixels in the first group of frame times is substantially equal to the total luminance in said pixels in the second group of frame times.

4. The method of claim 2, wherein image data is so adjusted such that the total luminance in said pixels in at least some of the first group of frame times is higher than the total luminance in said pixels in the second group of frame times.

5. The method of claim 1, wherein the pixels are arranged in a plurality of lines and the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a second group of frame times following the first group, and wherein the luminance in the first period has a maximum luminance and the luminance in the second period has a minimum luminance, and the maximum value in said pixels in the first group is lower than the luminance in said pixels in the second group, said method further comprising:

adjusting the image data provided to said pixels in the first group of frame times so as to increase the maximum luminance in said pixels in the first group of frame times.

6. The method of claim 5, wherein image data is so adjusted such that the maximum luminance in said pixels in the first group of frame times is substantially equal to the maximum luminance in said pixels in the second group of frame times.

7. The method of claim 5, wherein image data is so adjusted such that the maximum luminance in said pixels in at least some of the first group of frame times is higher than the maximum luminance in said pixels in the second group of frame times.

8. The method of claim 1, wherein the pixels are arranged in a plurality of lines and the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a second group of frame times following the first group, and wherein the luminance in the first period has a maximum luminance and the luminance in the second period has a minimum luminance, and the maximum value in said pixels in the first group is lower than the luminance in said pixels in the second group, said method further comprising:

adjusting the image data provided to said pixels in the first group of frame times so as to decrease the minimum luminance in said pixels in the first group of frame times.

9. The method of claim 8, wherein image data is so adjusted such that the minimum luminance in said pixels in the first group of frame times is substantially equal to the minimum luminance in said pixels in the second group of frame times.

10. The method of claim 8, wherein image data is so adjusted such that the minimum luminance in said pixels in at least some of the first group of frame times is lower than the minimum luminance in said pixels in the second group of frame times.

11. The method of claim 1, wherein the pixels are arranged in a plurality of lines and the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a second group of frame times following the first group, and wherein a sum of the luminance in the first period and the luminance in the second period yields a total luminance, and the total luminance in said pixels in the first group is lower than the total luminance in said pixels in the second group, said method further comprising:

adjusting at least the first period in the first group of frame times so as to increase the total luminance in said pixels in the first group of frame times.

12. The method of claim 1, wherein the pixels are arranged in a plurality of lines, and the luminance in said pixels in the first period is adjustable by a charging time, and wherein the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a second group of frame times following the first group, and wherein a sum of the luminance in the first period and the luminance in the second period yields a total luminance, and the total luminance in said pixels in the first group is lower than the total luminance in said pixels in the second group, said method further comprising:

adjusting the charging time in the first period in the first group of frame times so as to increase the total luminance in said pixels in the first group of frame times.

13. The method of claim 1, wherein the pixels are arranged in a plurality of lines and the luminance in said pixels in the first period is adjustable by a charging time, and wherein the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a second group of frame times following the first group, and wherein the luminance in the first period has a maximum luminance and the luminance in the second period has a minimum luminance, and the maximum value in said pixels in the first group is lower than the luminance in said pixels in the second group, said method further comprising:

adjusting the charging time in the first period in the first group of frame times so as to increase the maximum luminance in said pixels in the first group of frame times.

14. An active matrix display having a plurality of data lines and a plurality of pixels operatively connected to the data lines to receive image data for producing luminance in the pixels, said display comprising:

a data source for providing the image data; and

a data adjustment module for adjusting the image data so that the image data is provided in a first period of a frame time, and at least part of the provided data is removed from the pixels after the first period so as to reduce the luminance in said pixels in a second period following the first period, wherein the sum of the first period and the second period is less than or substantially equal to one frame time.

15. The display of claim 14, wherein the pixels are arranged in a plurality of lines and the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a following second group of frame times, and wherein a sum of the luminance in the first period and the luminance in the second period yields a total luminance, and the total luminance in said pixels in the first group is lower than total the luminance in said pixels in the second group, wherein the data adjustment module is adapted to further adjust the image data provided to said pixels in the first group of frame times so as to increase the total luminance in said pixels in the first group of frame times.

16. The display of claim 14, wherein the pixels are arranged in a plurality of lines and the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a second group of frame times following the first group, and wherein the luminance in the first period has a maximum luminance and the luminance in the second period has minimum luminance, and the maximum value in said pixels in the first group is lower than the luminance in said pixels in the second group, wherein the data adjustment module is adapted to further adjust the image data provided to said pixels in the first group of frame times so as to increase the maximum luminance in said pixels in the first group of frame times.

17. The display of claim 14, wherein pixels are arranged in a plurality of lines and the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a second group of frame times following the first group, and wherein the luminance in the first period has a maximum luminance and the luminance in the second period has minimum luminance, and the maximum value in said pixels in the first group is lower than the luminance in said pixels in the second group, wherein the data adjustment module is adapted to further adjust the image data provided to said pixels in the first group of frame times so as to decrease the minimum luminance in said pixels in the first group of frame times.

18. The display of claim 14, wherein the pixels are arranged in a plurality of lines for forming a display image, and the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a second group of frame times following the first group, and wherein a sum of the luminance in the first period and the luminance in the second period yields a total luminance, and the total luminance in said pixels in the first group is lower than the total luminance in said pixels in the second group, wherein the data adjustment module is adapted to further adjust at least the first period in the first group of frame times so as to increase the total luminance in said pixels in the first group of frame times.

19. The display of claim 14, wherein the pixels are arranged in a plurality of lines for forming a display image and the luminance in said pixels in the first period is adjustable by a charging time, and wherein the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a second group of frame times following the first group, and wherein a sum of the luminance in the first period and the luminance in the second period yields a total luminance, and the total luminance in said pixels in the first group is lower than the total luminance in said pixels in the second group, wherein the data adjustment module is adapted to further adjust the charging time in the first period in the first group of frame times so as to increase the total luminance in said pixels in the first group of frame times.

20. The display of claim 14, wherein the pixels are arranged in a plurality of lines for forming a display image and the luminance in said pixels in the first period is adjustable by a charging time, and wherein the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a second group of frame times following the first group, and wherein the luminance in the first period has a maximum luminance and the luminance in the second period has minimum luminance, and the maximum value in said pixels in the first group is lower than the luminance in said pixels in the second group, wherein the data adjustment module is adapted to further adjust the charging time in the first period in the first group of frame times so as to increase the maximum luminance in said pixels in the first group of frame times.

21. The display of claim 14, comprising a liquid crystal display.

22. A data adjustment module for use in an active matrix display having a plurality of data lines and a plurality of pixels operatively connected to the data lines to receive image data for producing luminance in the pixels, wherein the pixels are arranged in a plurality of lines for forming display images in a plurality of frames, said data adjustment module comprising:

a timing generator, adapted to compare the image data in a current frame with the input data in one or more previous frames, for providing a signal based on said comparing; and

a timing controller for controlling the image data, based on the signal, such that the image data is provided to the pixels in a first period of a frame time, and at least part of the image data is removed from the pixels in a second period of frame time following the first period in order to reduce the luminance in said pixels in the second period, wherein the sum of the first period and the second period is less than or substantially equal to one frame time.

23. Th data adjustment module of claim 22, wherein the pixels are arranged in a plurality of lines and the lines are driven repetitively for forming the display image in a plurality of frame times, the plurality of frame times comprising a first group of frame times and a following second group of frame times, and wherein a sum of the luminance in the first period and the luminance in the second period yields a total luminance, and the total luminance in said pixels in the first group is lower than the total luminance in said pixels in the second group, wherein the data adjustment module is adapted to further adjust the image data provided to said pixels in the first group of frame times so as to increase the total luminance in said pixels in the first group of frame times.