Patent ID: 7511485

Claim:
A magnetic filed measurement method using a magnetic field sensor of a detection width L, the method comprising the steps of: scanning the magnetic field sensor in a direction of the detection width; measuring a magnetic field strength at each spacing s which is smaller than the detection width L; performing arithmetic processing including addition and subtraction in relation to the magnetic field strength values measured at the each spacing s; and determining the magnetic field strength at the detection width of the spacing s along a scanning direction, wherein the arithmetic processing: determines a difference between the magnetic field strength value measured at a desired position and the magnetic field strength value at an adjacent position separated from the desired position by the spacing s, determines the differences between the magnetic field strength values at a plurality of third positions separated from the desired position by an integer multiple of the detection width L and the magnetic field strength values at a plurality of fourth positions corresponding to the plurality of third positions with each fourth position being separated from a respective third position by the spacing s, and adds these differences to determine the magnetic field strength at the desired position.