| 摘要 |
<p>PURPOSE:To suppress the level of a spurious signal at the time of reproducing and hence to promote the reliability by connecting a capacitor via a changeover switch to an input terminal of a recording current amplifier and connecting this with a current source which is invertible in polarity by a control signal. CONSTITUTION:The changeover switches 16 and 17 are formed on the input side of the 1st and 2nd recording current amplifiers 14 and 15 consisting of insulated gate type transistors. A power voltage 8 is connected to terminals on one side of the switches 16 and 17, while the capacitor 18 is connected to terminals on the other side, which is also connected with the current source 19 invertible in polarity with an output signal of a timing pulse producing circuit 6. Then, a voltage wave synchronized with a control signal to be generated by discharging a charge of the capacitor 18 by the current source 19 is selectively inputted to the amplifiers 14 and 15 via the switches 16 and 17. Consequently, a recording current with current changes at the end and beginning in proportion to the square of time can be impressed upon a control head 1. By this method, the level of the spurious signal at the time of reproducing is suppressed to a minimum and hence the reliability is promoted.</p> |
