| 摘要 |
PURPOSE:To displace a video head as an object displacement by providing a moving head displacing the position of a head gap in response to an impressed drive signal, a drive amplifier generating its driven signal and a nonlinear amplifier connected to a pre-stage of the drive amplifier. CONSTITUTION:A moving head drive signal fed to an input terminal 11 is provided with a nonlinear characteristic by a nonlinear amplifier 12, amplified to an amplitude of several hundreds vp-p by the drive amplifier 13 and outputted from an output terminal 14. A bimorph plate is connected to the output terminal 14 and the video head fitted to the tip of the moving head is displaced by the deflection of the bimorph plate. When the amplitude of the drive voltage is comparatively small, the video head is displaced linearly proportional to the driven voltage. When the amplitude of the drive voltage is comparatively large, the displacement of the video head is too large with respect to the drive voltage and the sensitivity of the bimorph plate is increased and the nonlinear amplifier acts like cancelling the nonlinear characteristic of the video head displacement.
|
