| 摘要 |
In one aspect, a speaker is provided having a coil and a diaphragm assembly coupled to the coil. The diaphragm assembly includes a piezo stiffener plate and a flexible membrane, the piezo stiffener plate including at least one piezo layer and at least one metal layer. The speaker is operable in a human audible frequency operating range and in an ultrasonic frequency operating range. In the ultrasonic frequency operating range, the piezo stiffener plate bends to extend the ultrasonic output beyond the ultrasonic range produced without the use of the piezo stiffener plate. In another aspect, a speaker is provided having a flexible membrane constructed at least partially of a piezo material. The speaker is operable in an ultrasonic frequency operating range wherein the piezo material bends to extend the ultrasonic output beyond the ultrasonic range produced without the use of the piezo material in the membrane. |
