PURPOSE: To monitor variations in floating height of a head facing a disk surface by identifying a sample value according to sampling of reading signals detected from a fixed area on a disk surface and calculating the variations in the floating height by using the frequency equalization numbers according to the sample values.
CONSTITUTION: A 6-bit sample value is obtained by converting a signal detected with head & disk 308 from a fixed area on a disk surface by an A/D converter 312 via a LPF 310. This sample value is made to pass through a cosine equalizer 314 and a digital filter 316 and is processed for a maximum likelihood detection by Viterbi decoder 318 and decoder 320. After the equalizer 314 has read frequency adjustment values K given to each transducer head into a microprocessor 322, they are used for a calculation of a floating height by a floating height measurement part 324. Thus, it is possible to monitor a floating height of a head without reduction in the function.
RICHIYAADO REO GARUBUREISU
POORU FUIRITSUPU HAWAADO
GUREGORII JIYON KAAUIN
GOODON JIEIMUSU SUMISU
