1. Field of the Invention
The present invention relates to an electrochromic display device.
2. Description of Related Art
Along with popularization of an electronic information network, publication in the form of an electronic book, namely electronic publication, has come to be actively performed, in place of publication in the form of a book using a conventional printing technique. As a device which displays electronic information distributed by such a network, for example, a CRT (Cathode Ray Tube) display and a backlight type liquid crystal display have generally been used. However, with respect to a display using these display devices, a place where a user can read the display is more restricted and a weight, size, shape and portability are inferior in terms of handling, compared with a conventional display printed on paper. Further, since these display devices consume large electrical power, when driving them with a battery, a display time is restricted. Moreover, since these display devices are light emission type displays, they may cause too much tiredness when a user fixes the eyes on the devices for a ling time.
Accordingly, a display device which can solve the problem as described above has been desired. Further, a rewritable display device has been desired. As such display device, one referred to as a paper-like display or electronic paper has been proposed. Specifically, there have hitherto been proposed, for example, a display device of a reflection type liquid crystal system, a display device of an electrophoretic system, a display device of a system in which a dichroic grain is rotated in an electric field, a display device of an electrochromic system (e.g. see Japanese Patent Application Laid-Open Publication No. 2005-84216), and the like.
However, since the electrochromic display device of Japanese Patent Application Laid-Open Publication No. 2005-84216 supplies a scanning signal to a gate wire to sequentially scan pixels so as to rewrite the pixels on a line-by-line basis, in the case of a display device with a large number of lines, such as a large screen and a high definition screen, rewriting its screen takes a long time.
Therefore, the conventional display device is not suitable for an application requiring a faster rewriting speed and a rapid switching of a screen.