Patent ID: 6356076
Filing Date: 2002-03-12
Classification: G01D

Abstract:
A magnetic incremental motion detection system for outputting a plurality of signals as a collective representation of an incremental movement of an object, said magnetic incremental motion detection system comprising:a target having a surface, said target adjoined to the object to thereby synchronously move with the object; a first set of indications adjoined to said surface of said target, said first set of indications being serially and uniformly disposed along a first area of said surface, said first set of indications having identical widths; a first magnetic sensor spatially positioned from said first area of said surface to thereby define a first air gap area therebetween, said first magnetic sensor being operable to output a first analog signal having a first duty cycle in response to a synchronous movement of said target with the object; a second magnetic sensor spatially positioned from said first area of said surface to thereby define a second air gap area therebetween, said second magnetic sensor being operable to output a second analog signal having a second duty cycle in response to said synchronous movement of said target with the object, wherein said first duty cycle and said second duty cycle are identical, and wherein said second analog signal is consistently out of phase by a same degree with said first analog signal; and a third magnetic sensor spatially positioned from said first area of said surface to thereby define a third air gap area therebetween, said third magnetic sensor being operable to output a third analog signal having a third duty cycle in response to a synchronous movement of said target with the object, wherein said third duty cycle is identical to said first duty cycle and to said second duty cycle.