Patent ID: 11860248
Assignee: SONY GROUP CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 14:
15. An apparatus for measuring magnetic characteristics, the apparatus comprising:
a first measurement section configured to apply a first magnetic field to a continuously moving magnetic recording medium to magnetically saturate the magnetic recording medium, apply a first polarized light to a surface of the magnetic recording medium to which the first magnetic field is being applied, and measure a light polarization state of a first reflected light that is reflected;
a second measurement section configured to apply a second magnetic field having an opposite direction of the first magnetic field to the continuously moving magnetic recording medium to magnetically saturate the magnetic recording medium, apply a second polarized light to the surface of the magnetic recording medium to which the second magnetic field is being applied, and measure a light polarization state of a second reflected light that is reflected;
a third measurement section configured to apply light to the surface of the continuously moving magnetic recording medium, and measure a light polarization state of a third reflected light that is reflected; and
an arithmetic section configured to calculate a ratio (ΔA20/ΔA10) of a difference ΔA20 (=A2−A0) between a mean value A0 of measurement values of the light polarization states of the first reflected light and the second reflected light and a measurement value A2 of the light polarization state of the third reflected light to a difference ΔA10 (=A1−A0) between the mean value A0 and the measurement value A1 of the light polarization state of the first reflected light.