Patent ID: 7193412

Claim:
An apparatus for sensing the position of a seat in a vehicle, said apparatus comprising: a permanent magnet having a direction of magnetization and establishing a magnetic field; a single pole spaced from said permanent magnet and having a surface in opposed facing relationship with one magnetic pole of said permanent magnet, said single pole disposed in said magnetic field; a magnetic sensor element disposed in said magnetic field and adjacent an end of said single pole, said magnetic sensor element having a flux receiving surface, said flux receiving surface in opposed facing relationship to said end of said single pole and being positioned substantially parallel to said direction of magnetization; and a target comprising a ferromagnetic material, at least one of said target and a sensor assembly, comprising said permanent magnet, said single pole and said magnetic sensor element, being configured for movement with said seat relative to the other of said target and said sensor assembly, whereby in at least one position of said at least one movable one of said target and said sensor assembly said target is disposed in said magnetic field and said magnetic sensor element is disposed between said end of said single pole and said target with no intervening ferromagnetic pole between said magnetic sensor element and said target, said sensor element being configured to provide a first output in response to a first level of magnetic flux from said magnet directed to said sensor element when said sensor element is disposed between said end of said single pole and said target and a second output different from said first output in response to a second level of magnetic flux from said magnet directed to said sensor element when said sensor element is not disposed between said end of said single pole and said target.