Driving methods for electrophoretic displays
View Patent ↗The driving system and methods of the present invention enable interruption of updating images. The system and methods not only have the advantage that they can prevent overdriving of an electrophoretic display, but they also allow updating images in the highest speed possible.
1. A driving method for a display device comprising a plurality of pixels for updating a current image being displayed on the display device to a next image, wherein the method comprises:
a) comparing the two images to identify current color state of each pixel in the current image and next color state of the pixel in the next image;
b) determining driving data for the pixels of the display device wherein the driving data for each pixel are expressed in number of frames required for a positive pulse or a negative pulse to drive the pixel from its current color state to its next color state;
c) determining existing driving data for the pixels of the display device in a pixel counter table; and
d) replacing the existing driving data of (c) with the sum of the driving data of (b) and the driving data of (c), in the pixel counter table; and
e) displaying the next image on the display device by driving the pixels of the display device towards their respective next color states until the driving data reach 0 for all the pixels in the pixel counter table.
2. The driving method of claim 1 wherein pixels of a first color are driven to a second color in a first phase and pixels of the second color are driven to the first color in a second phase.
3. The driving method of claim 2 wherein a driving sequence comprises one or more of the first phases and one or more of the second phases.
4. The driving method of claim 3 wherein the order in which the first phase and the second phase are carried out depends on timing of an interrupting command.
5. The driving method of claim 4 wherein after receiving the interrupting command, the first phase is completed before the second phase.
6. The driving method of claim 4 wherein after receiving the interrupting command, the second phase is completed before the first phase.
7. The driving method of claim 4 wherein immediately before and after the interrupting command, the driving is carried out in the same phase.
8. The driving method of claim 3 wherein the first phase and the second phase are carried out in an interleaving manner.
9. The driving method of claim 1 wherein driving pixels of a first color to a second color and driving pixels of the second color to the first color take place in the same phase.
10. The driving method of claim 1 in step (e), pixels having driving data expressed in number of frames for a positive pulse are driven to 0 before pixels having driving data expressed in number of frames for a negative pulse are driven to 0.
11. The driving method of claim 1 in step (e), pixels having driving data expressed in number of frames for a positive pulse are driven to 0 before initiating driving pixels having driving data expressed in number of frames for a negative pulse.
12. The driving method of claim 1 in step (e), pixels having driving data expressed in number of frames for a negative pulse are driven to 0 before pixels having driving data expressed in number of frames for a positive pulse are driven to 0.
13. The driving method of claim 1 in step (e), pixels having driving data expressed in number of frames for a negative pulse are driven to 0 before initiating driving pixels having driving data expressed in number of frames for a positive pulse.
14. The driving method of claim 1 in step (e), pixels having driving data expressed in number of frames for a positive pulse and pixels having driving data expressed in number of frames for a negative pulse are driven at the same time.