| 摘要 |
<p>PURPOSE:To detect abnormality such as a crack on an ultrasonic vibrater or defective contact between the ultrasonic vibrater and a guide by detecting a distortion component in a drive signal to be supplied to the ultrasonic vibrater by a distortion detecting means. CONSTITUTION:In a tape guide device capable of vibrating tape guides 114a and 114t with a standing wave by the ultrasonic vibrater 113s and 113t fixed to the tape guides 114s and 114t, the drive signal from a drive circuit 112s is taken in voltage by an amplifier circuit 130 of a distortion detecting circuits 121s and 121t, and supplied via an HPF 131 and a band elimination filter (BEF) 132 to a peak hold circuit 133. The voltage signal removed in its resonance frequency component is turned into an approximately DC voltage signal by the circuit 133, and the presence of a higher harmonic component in the drive signal is detected by a control part 100 with this voltage signal. By this method, abnormality of a crack of the ultrasonic vibrater or defective contact with the tape guides, etc., can be detected in its early stages.</p> |
