Methods for driving electro-optic displays
An electro-optic display uses first and second drive schemes differing from each other, for example a slow gray scale drive scheme and a fast monochrome drive scheme. The display is first driven to a pre-determined transition image using the first drive scheme, then driven to a second image, different from the transition image, using the second drive scheme. The display is thereafter driven to the same transition image using the second drive scheme; and from then to a third image, different from both the transition image and the second image, using the first drive scheme.
1. A method of operating an electro-optic display using first and second drive schemes differing from each other, the method comprising, in this order:
driving the display to a pre-determined transition image using the first drive scheme;
driving the display to a second image, different from the transition image, using the second drive scheme
driving the display to the same transition image using the second drive scheme; and
driving the display is driven to a third image, different from both the transition and the second image, using the first drive scheme,
wherein the transition image is only provided between transitions between the drive schemes.
2. A method according to claim 1 wherein the first drive scheme is a gray scale drive scheme capable of driving the display to at least four gray levels.
3. A method according to claim 2 wherein the first drive scheme is a gray scale drive scheme capable of driving the display to at least eight gray levels.
4. A method according to claim 1 wherein the second drive scheme is an application update drive scheme having fewer gray levels than the first drive scheme and a maximum update time less than the length of the saturation pulse of the display.
5. A method according to claim 1 wherein the transition image comprises a single tone applied to all the pixels of the display.
6. A method according to claim 1 wherein the display is provided with a plurality of transition images and a display controller is arranged to choose one transition image dependent upon the image already present on the display.
7. A method according to claim 1 wherein the display is driven successively to a plurality of transition images before being driven to the second image and/or before being driven to the third image.
8. A method according to claim 1 wherein the electro-optic display comprises a rotating bichromal member or electrochromic material.
9. A method according to claim 1 wherein the electro-optic display comprises an electrophoretic material comprising a plurality of electrically charged particles disposed in a fluid and capable of moving through the fluid under the influence of an electric field.
10. A method according to claim 9 wherein the electrically charged particles and the fluid are confined within a plurality of capsules or microcells.
11. A method according to claim 9 wherein the electrically charged particles and the fluid are present as a plurality of discrete droplets surrounded by a continuous phase comprising a polymeric material.
12. A method according to claim 9 wherein the fluid is gaseous.