Patent ID: 6602571
Filing Date: 2003-08-05
Classification: G01D,H01F,Y10T

Abstract:
A method for manufacturing a magnetic encoder for use with a sensor on a semiconductor chip that is placed opposite the magnetic encoder, and for producing codes as represented by a sequence of pulses generated by magnetic forces, said method comprising:providing an unvulcanized raw rubber; providing a magnetic ferrite powder; adding said magnetic ferrite powder to said unvulcanized raw rubber, thereby providing a mixture of said magnetic ferrite powder and said unvulcanized raw rubber; forming said mixture of said magnetic ferrite powder and said unvulcanized raw rubber into a sheet blank that contains said magnetic ferrite powder aligned regularly in a particular orientation; removing an annular blank from said sheet blank; associating said annular blank and a supplemental ring with one another and then applying compressive forces and heat to said annular blank and said supplemental ring, thereby vulcanizing the rubber of said annular blank and joining said annular blank to said supplemental ring so as to provide a composite annular member; and magnetizing said composite annular member such that S poles and N poles are alternately arranged around a circumference of said composite annular member.