a line scanner compries a conductive film which has been patterned to define a plurality of electrodes , each with an attached lead , is covered with a layer of photosensitive a - silicon and the silicon in turn is covered with an insulating resin . the insulating film is patterned to open a linear window which exposes equal amounts of each electrode and attached lead and a common electrode overlies the resin and contacts the electrodes and leads through the window .