| 摘要 |
PURPOSE:To perform reproduction with highest sensitivity even with a recording signal of a short wavelength by setting the ferromagnetic resonance magnetic field of a magnetic material at the value near a saturated magnetic field and producing the variation of high frequency characteristics corresponding to a signal magnetic field in an unsaturated region where the external magnetic field of the magnetic material reaches the saturated magnetic field. CONSTITUTION:A part of a head magnetic pole 23 consists of a thin film magnetic material 24 whose mu' and mu'' are varied in response to a signal magnetic field. A high frequency circuit 26 consists of a high frequency oscillator 27, matching capacitors 28 and 29, a resonance capacitor 30, etc. Both mu' and mu'' of the material 24 vary by the signal magnetic field given from a magnetic recording medium 21 and accordingly the impedance of a conductor bar 25 varies. Therefore the high frequency output voltage extracted out of the circuit 26 via the bar 25 varies in response to said impedance variation. Thus the high frequency output voltage is detected by a peak wave detecting circuit 34, for example, consisting of a diode 31, a resistance 32 and a capacitor 33. As a result, a signal reproduction output 35 is obtained. |
