1. Field of the Invention
The present invention relates to a liquid crystal display device with a touch panel.
2. Description of the Related Art
An information communication terminal such as a computer, in which a touch panel arranged so as to be overlapped on a display screen is used as an input device has widely been used. A liquid crystal display device which is widely used as a display device is a device which displays an image by changing the orientation of liquid crystal compositions sealed between two substrates, namely a thin film transistor substrate (hereinafter, referred to as a “TFT substrate”) and a color filter substrate, by variations in an electric field and controlling the degree of light transmission passing through a liquid crystal panel. According to an in-plane switching (IPS) scheme in which both a pixel electrode and a common electrode are arranged on the side of the TFT substrate, in particular, a so-called lateral electric field is formed, and display with a wide view angle is realized.
A touch panel is an input device which causes a processing apparatus to perform processing by recognizing coordinates on the panel touched with a finger or the like of a user. For the touch panel, a resistance film scheme in which variations in a resistance value at a touched part is detected, an optical sensor scheme in which variations in light amount at a part blocked by touching is detected, an electrostatic capacity coupling scheme in which variations in capacity are detected, and the like are known. The electrostatic capacity coupling scheme has been widely used in terms of high transmittance of the panel without degrading display quality, and there is no occurrence of contact with other electrodes, which brings about high durability, for example.
JP 2009-244958A discloses a liquid crystal display device with a touch panel of the IPS scheme, the thickness of which is reduced by using a common electrode of the liquid crystal display device as a drive electrode of the touch panel. JP 2007-095190A discloses a shift register circuit which is used in a display device such as a liquid crystal display device.