| 摘要 |
PURPOSE:To realize proper copying corresponding to the material of each recording medium to be used by pressurizing a master recording medium contact with a slave recording medium, and adjusting the phase difference of the AC exciting currents of two exciting means interposing both planes. CONSTITUTION:Magnetic heads H1 and H2 are provided so that mutual gap can be confronted with the inside of drums D1 and D2 consisting of nonmagnetic material. A master tape M and a sleeve tape S are pressurized contact by the drums D1 and D2 with a driving tape T, and are fed by applying a bias magnetic field for copying from the heads H1 and H2. The serial resonant oscillation circuit OSC of a bias magnetic field generation device oscillates by the winding coil L1 of the head H1 and the serial resonance frequency of a capacitor C1, and oscillation output is inputted to a phase shifter circuit (phi). And a phase shift characteristic is adjusted by a variable resistor R in the circuit (phi), and the head H2 can be driven via a power amplifier PW. In such a way, it is possible to change the bias magnetic field by adjusting the resistor R, and to perform the copying suitable for tapes of various kinds. |
