Abstract: In each pixel region 41 of a liquid crystal TFT array substrate, formed are an ITO transparent electrode 43, a gate line 48, a data line 46, a TFT active device 45, an identification mark 50 and the like. The identification mark 50 is provided by forming a bar code made of silver on the gate line 48. Since the identification mark 50 is formed within the pixel region 41, a transistor to be repaired can be surely identified, for example, by detecting the identification mark in a repair processing of the TFT array substrate. Furthermore, in an information processing apparatus for inputting figures and characters onto a screen using a laser pen, a locus of the laser pen can be accurately specified by specifying a position of a pixel region from an identification mark detected by the laser pen, and the figures and the characters input can be recognized minutely.