| 摘要 |
PURPOSE:To form a speaker whose directivity is controllable in a wide range with a simple constitution by combining a parametric speaker and a reflecting plate. CONSTITUTION:A sound generated by an ultrasonic generator 1 is reflected by the reflecting plate 2 made of aluminum. The plate 2 provided with a moving mechanism and is movable in angular motion. When the plate 2 is in position A as shown by full lines, the coverage A' is the audible range, but when in position B, the coverage B' is the audible range. In case the audible range is fixed, the reflecting plate 2 is fixed at a specified angle. |
