IMPROVED SCROLLING FUNCTION IN AN ELECTROPHORETIC DISPLAY DEVICE

摘要

Bi-stable electrophoretic display device (1) having a normal mode and a scrolling mode, in which image transitions are effected by causing the charged particles (8,9) to toggle between the intermediate optical states (e.g. grey-to-grey) or between an extreme optical state and an intermediate optical state (e.g. white-to-light grey), with a corresponding short update time tscroll. When the device (1) enters a scrolling mode in response to a scrolling command from a user, picture elements are first driven to a special scrolling optical. state, after which drive waveforms for scrolling mode are used for fast toggling between two scrolling states. An increased scrolling speed and very short scrolling time can be realized, without adversely affecting image quality during a normal mode.