Patent ID: 7257755

Claim:
A driver IC comprising: a plurality of output pads; and a plurality of signal switch circuits, each of the signal switch circuits being provided on one of signal paths respectively connected to the output pads, wherein each of the signal switch circuits switches between a first state in which a signal from an upstream side of the signal path is allowed to pass through the signal switch circuit and a second state in which a level pattern of signals from the output pads is fixed to an inspection level pattern, according to a control signal; wherein the inspection level pattern includes a level pattern in which signals output from adjacent two of the output pads have different signal levels; the output pads are arranged along a long side of the driver IC in M rows (M is a natural number) which are arranged along a short side of the driver IC; the inspection level pattern includes a fixed pattern in which signals output from two of the output pads which are adjacent to each other in a direction of the long side of the driver IC have different signal levels; M is a natural number greater than one; and the inspection level pattern includes a fixed pattern in which signals output from two of the output pads which are adjacent to each other in a direction of the short side of the driver IC have different signal levels.