Patent ID: 7365530

Claim:
Apparatus for detecting a vibration of an object adapted for rotation, comprising: a plurality of magnetic field sensors for generating an RDIFF signal proportional to a magnetic field at a first location relative to the object and an LDIFF signal proportional to a magnetic field at a second location relative to the object; at least two rotation detectors, wherein a first one of the rotation detectors is coupled to at least one of the magnetic field sensors and is responsive to the RDIFF signal for providing a first output signal indicative of rotation of the object and wherein a second one of the rotation detectors is coupled to at least one of the magnetic field sensors and is responsive to the LDIFF signal for providing a second output signal indicative of rotation of the object; and a vibration processor responsive to the first and second output signals from the at least two rotation detectors for detecting the vibration of the object, the vibration processor comprising one or more vibration detectors including: a phase-overlap processor to identify a first signal region associated with the RDIFF signal and a second signal region associated with the LDIFF signal, to identify a first overlap as an overlap of the first signal region and the second signal region, and to generate a phase-overlap output signal indicative of the vibration of the object in response to the first overlap.