| 摘要 |
PURPOSE:To eliminate a shift of tracking in the course of scanning by supplying the distortion erasing voltage for eliminating the residual distortion due to hysteresis of an electrostrictive element, to the element, in a non-scanning period Tn of a magnetic head, and also correcting a waveform of tracking correcting voltage Et. CONSTITUTION:Distortion erasing voltage E22 is supplied to a trap circuit 26, and is supplied to an amplifier 28 after the resonance frequency component of an element 11 is eliminated. Also, in a forming circuit 20, saw tooth voltage Eh which starts from ''0'' and ends in a level 2Es only in a period Tt is formed, and this voltage Eh is supplied to a non-linear circuit 27. This non-linear circuit 27 has an input/output characteristic being complementary to a non-linear characteristic of the element 11, and in accordance with the non-linear characteristic of the element, the voltage Eh whose amplitude (waveform) is corrected is fetched. Subsequently, the corrected voltage Eh is supplied to the amplifier 28, and tracking correcting voltage Et having distortion erasing voltage Ed being added voltage of the voltage E22 and Eh is fetched, and is supplied to the element 11 for supporting heads 1A, 1B. |
