Patent ID: 7298579

Claim:
A method of recording/reproducing comprising: reproducing on a magnetic recording medium that includes a servo area where servo data used for detecting a position of a magnetic head on the magnetic recording medium is recorded, and a writable data area, arranged side by side with the servo area in the track direction, on which user data is written by the magnetic head, the servo area including a preamble area where a preamble recording pattern that represents data used for providing a clock synchronization of the servo data is formed by a plurality of magnetic sections, and a burst area where data used for detecting a relative position of the magnetic head with respect to a track center position of the servo data is recorded and on which a single burst recording pattern which is a layout pattern that tilts to the preamble recording pattern with a predetermined tilt angle is formed by a plurality of magnetic sections, wherein reproducing includes detecting a phase difference of a burst reproduced signal of the burst area from a reproduced signal of the preamble area, based upon sample values at respective points in the preamble area, which are sampled by using a synchronous clock determined by a reproduced signal processing of the preamble area and a plurality of predetermined coefficients, as phase difference information corresponding to a plurality of phase differences; and detecting position deviation information indicating a relative distance of the magnetic head from the track center position based upon the phase difference information, wherein detecting a phase difference includes calculating a first inner product value obtained by multiplying the sample value at each of the points by a sine wave value serving as the coefficient; calculating a second inner product value obtained by multiplying the sample value at each of the points by a cosine wave value serving as the coefficient; calculating a third inner product value obtained by multiplying the sample value at each of the points by a sine wave value having a phase difference of 180 degrees serving as the coefficient, integrating the first inner product value; integrating the second inner product value; integrating the third inner product value; dividing the integrated second inner product value by the integrated first inner product value to find a first divided value, and outputting resulting the first divided value as the phase information; and dividing the integrated third inner product value by the integrated second inner product value to find a second divided value, and outputting resulting the second divided value as the phase difference information.