| 摘要 |
PURPOSE:To eliminate the influence to a screen at a drive time by driving an elastic wave motor associated in a television camera during a vertical blanking period of a video signal. CONSTITUTION:A drive signal outputted from an oscillator 6 is applied through an analog switch 21, an amplifier 22 and an inductor 24 to a piezoelectric unit 5B of a phase B. Simultaneously, the drive signal is shifted by a 90 deg. phase shifter 7, and applied through an amplifier 23 and an inductor 25 to a piezoelectric unit 5A of the phase A. The switch 21 is controlled by a switch pulse 2 outputted from a monostable multivibrator 27 triggered by a vertical synchronizing signal obtained from a synchronizing signal generator 26. This switch pulse has a pulse width slightly narrower than the vertical blanking period of a video signal obtained from a television camera. As a result, an elastic wave motor is driven only during the vertical blanking period. |
