Patent ID: 7002762

Claim:
A method for retrieving a signal corresponding to a distribution of magnetically polarized regions on a carrier of magnetically coated media by means of a magnetoresistive transducer coupled to a read channel circuit, the retrieved signal being free from intersymbol interference, the method comprising the steps of: (a). providing magnetoresistive transducer positioning means for positioning the magnetoresistive transducer to a user-selectable location over the carrier of magnetically coated media, said positioning means including drive means for producing a change in magnetic flux about the magnetoresistive transducer upon positioning thereof at said user-selectable location, said change in magnetic flux corresponding to the magnetically polarized regions on the carrier of magnetically coated media so as to produce a voltage at an output of the read channel circuit responsive thereto; (b). constructing a spatial image of a response function of the magnetoresistive transducer by measuring said voltage signal at said output of the read channel circuit responsive to a known distribution of the magnetically polarized regions disposed on a first carrier of magnetically coated media; (c). constructing a spatial image of raw read signal data by measuring said voltage signal at said output of said read channel circuit responsive to an unknown distribution of the magnetically polarized regions disposed on a second carrier of the magnetic media; (d). constructing a spatial image of a distribution of virtual magnetic charge corresponding to said unknown distribution of the magnetically polarized regions on said second carrier of magnetically coated media by spatial deconvolution of said spatial image of said response function of the magnetoresistive transducer and said spatial image of said raw read signal data; and (e). obtaining the retrieved intersymbol interference-free signal by spatially differentiating said spatial image of said distribution of virtual magnetic charge.