Patent ID: 8350973

Claim:
A liquid crystal display device having an area sensor function for detecting an external input position by detecting an image on a panel surface, the liquid crystal display device comprising: a liquid crystal panel including: an active matrix substrate; a counter substrate; and a liquid crystal layer provided between the active matrix substrate and the counter substrate; a backlight illuminating the liquid crystal panel; a position detecting section (i) including a plurality of optical sensor elements each detecting an intensity of received light and (ii) detecting the external input position according to detection of the image on the panel surface by use of the plurality of optical sensor elements; and a reflectance changing section reducing a reflectance of light from the backlight in response to application of pressure on the panel surface, the reflectance changing section including at least two elastic films, the reflectance changing section being configured so that in a state where no pressure is applied on the panel surface, an air layer is formed between the two elastic films whereas in a case where pressure is applied on the panel surface, the two elastic films contact each other.