Patent ID: 7332718

Claim:
A method for finding disconnection of a plurality of conductive wires that are formed on a vehicular plate glass and are parallel with each other, the method comprising the steps of: (a) applying a voltage to the conductive wires; (b) imaging thermal radiation from a surface of the conductive wires by an infrared image sensor, while the step (a) is conducted, thereby producing a temperature distribution image; (c) selecting an inspection portion from the temperature distribution image, the inspection portion having a size to cover only a portion of each conductive wire; (d) subjecting only the inspection portion of the temperature distribution image having a size less than the entirety of each conductive wire to a binarization by an image processor, thereby producing a binarized temperature distribution image of only the inspection portion; and (e) comparing the binarized temperature distribution image with a data representing a pattern of the conductive wires to determine whether a disconnection exists anywhere in the entirety of the conductive wires, based on the binarized temperature distribution image of only the inspection portion.