1. Technical Field
The present invention relates to control devices, display devices and methods for controlling a display device.
2. Related Art
Among electrophoretic type display devices, there is a type that performs each rewriting operation by applying voltages multiple times. Such a rewriting operation may be performed when it takes a relatively long time for display elements to change their display state (i.e., gradation). When such a rewriting operation is performed, unless one rewriting operation is completed (in other words, unless the time for multiple voltage applications has elapsed), the next rewriting operation cannot be started.
Japanese Laid-open Patent Application JP-A-2009-251615 (Patent Document) describes a technology for rewriting an image at each of divided regions by a pipeline processing in a display device such as an electrophoretic display device or the like. By using such a method, a rewriting operation can be started on a region where rewriting is not performed, without depending on the rewriting state of other regions, such that the time required for rewriting may be made shorter, compared to the case where the entire image is rewritten at once.
Incidentally, in an area of the electrophoretic display device where rewriting is performed a plurality of times, an afterimage of the image may remain due to operation failure of the electrophoretic particles. In order to erase such an afterimage, the entire target area is displayed in black or the entire target area is displayed in white, a so-called refreshing operation may be performed. However, according to the technology described in the Patent Document, partial refreshing is not described, but refreshing is performed over the entire display area. Therefore, while refreshing is performed, other rewriting operations are stopped.