Patent ID: 6448792
Filing Date: 2002-09-10
Classification: G01B,G01D

Abstract:
An edge sensor device comprising:a) a pair of transmitting electrodes made of electro-conductive material, each electrode having almost identical shape of triangular plate where the electrodes are disposed parallel to the moving direction of the edge portion of an electro-conductive strip and in the opposite directions each other; b) a receiving electrode disposed facing said transmitting electrodes and with said electro-conductive strip inserted between the transmitting electrodes and said receiving electrode; c) a signal source applying respectively an alternating signal S1 with frequency f1 to one of said transmitting electrodes and an alternating signal S2 with frequency f2 to the other of said transmitting electrodes; and d) a sensor means for evaluation of the insertion extent of said electro-conductive strip between said transmitting electrodes and said receiving electrode from a current I1 with frequency f1 and a current I2 with frequency f2 generated on said receiving electrode.