| 摘要 |
PURPOSE:To insulate a high molecular piezoelectric film from external acoustic sound and light rays by setting the main direction of propagating vibration wave produced at an input electrode perpendicularly to an electrode confronting direction and reducing the reflecting noise applied to an output electrode. CONSTITUTION:Since the elongating and contracting motion of a film due to reverse piezoelectricity produced at input side electrodes 1, 1' occur in the main orientation axial direction (an MD direction of arrow) of the film when electrode pairs 1, 1' and 2, 2' are confronted in the vicinity at an equal interval, the vibration wave is propagated in the MD direction, and is reflected at both ends of the film in the MD direction. If the MD direction of the film is a direction perpendicular to the electrode confronting direction as designated by an arrow (b), the main direction of the vibration wave propagating from the electrodes 1, 1' is a direction as designated by (b), and almost no reflecting wave noise is applied to the electrodes 2, 2'. Thus, the film can be insulated from external acoustic sound and light rays. |
