| 摘要 |
PROBLEM TO BE SOLVED: To optimally maintain reproducing signal grade by setting the optimum reproducing power based on an amplitude ratio of a reproducing signal amplitude by magnetic wall transfer from the front to the same from the rear both in the advancing direction of a reproducing optical beam. SOLUTION: The ratio of an amplitude difference between prescribed two magnetic domain lengths to a specific amplitude is equivalent to the ratio Vβ/Vα, assuming that Vαis a reproducing signal amplitude by magnetic wall transfer from the front in the advancing direction of an optical beam and that Vβis the amplitude of a ghost waveform by magnetic wall transfer from the rear in the advancing direction of the optical beam. By the dependency of reproducing power, the relation of this amplitude ratio Vβ/Vαis uniquely determined by the reproducing power. Consequently, by detecting this amplitude ratio of Vβ/Vα, condition of the reproduction can be discriminated to be good or not. On the basis of this principle, the amplitude ratio Vβ/Vαis detected, on which the optimum reproducing power is set.
|
