Patent ID: 6955951

Claim:
A method for monitoring a liquid crystal display device, comprising: a substrate in which a display area is delimited; two series of bus-lines supported by the substrate, one ends of the bus-lines being located in proximity to one side of the display area, another ends of the bus-lines being located in proximity to another side of the display area which is opposite to the one side of the display area, the two series of bus-lines being arranged to extend over the display area in such a manner that the one series of bus-lines is orthogonal to the other series of bus-lines; and a conductive auxiliary wiring pattern supported by the substrate, which extends in such a manner that the pattern crosses another end(s) of the bus-line(s), which is/are all to be monitored, of the one series of bus-lines via an electrically insulating layer, and which is led to a predetermined location on a side of one ends of the bus-lines of the other series to form a coupling portion electrically connectable to an exterior in the predetermined location, the method comprising monitoring an electrical characteristic of any of the bus lines using the coupling portion of the device, wherein the coupling portion is connected to an extension wiring pattern which is electrically conductive and supported by a TAB tape, and wherein the electrical characteristic is monitored with an exposed surface of the extension wiring pattern.