| 摘要 |
PURPOSE:To control an electromechanical transducer well by eliminating a high frequency part from a signal, which does not include a negative feedback signal, with an LPF in the input side of a driving circuit and attenuating a feedback circuit and providing an HPF. CONSTITUTION:The output signal of an LPF2 has a feedback signal subtracted in a subtracting circuit 3 and is raised to a voltage required for driving a bimorph by a high voltage drive amplifier 4 and is applied to the bimorph. A strain gauge 11 senses the displacement of the bimorph, and this sense voltage is inputted to an HPF13 after a gain is attained in an amplifier 12. The output of the HPF13 has the gain adjusted in a gain adjusting means 14, and the damping coefficient at the first resonance point is increased in a differentiation circuit 15. An RF signal is sampled at intervals of one field to correct the head position, and the head is always placed on a track at the slow still reproducing time to obtain one-field components of picture without noise bars. |
