Abstract: A piezoelectric device is provided with a sound source IC, an amplifier for amplifying a sound source from the sound source IC, a piezoelectric speaker for generating sound based on a drive signal from amplifier, an MPU for performing a predetermined control process on the drive signal, a memory for storing temperature dependency information about the piezoelectric constant (d14) and Young's modulus E of the piezoelectric speaker, and a temperature sensor for detecting an ambient temperature. MPU has correcting unit, compares a detected result of the temperature sensor with the temperature dependency information, and performs temperature correction on the drive signal serving as an acoustic signal based on a compared result. The piezoelectric speaker outputs the acoustic signal temperature-corrected by correcting unit.

Abstract: A touch panel capable of detecting a pen and a finger, capable of corresponding to multi-touch, capable of detecting pressing force, and capable of reducing the use amount of a transparent electrode as much as possible. The touch panel has a piezoelectric sheet of poly-L-lactic acid having a predetermined stretching axial direction, electrodes that are opposed to each other and formed on the piezoelectric sheet do not cover the entire surface of the piezoelectric sheet and are formed so that they are discretely distributed in plural positions. The piezoelectric sheet is brought into the condition that tension is imparted in directions not coincident with the stretching axial direction.

Abstract: A power generation apparatus includes a dielectric, a movable member being opposed to the dielectric with a predetermined distance, and an electret and an opposing electrode that are formed on the surface of the movable member facing the dielectric so as to generate a fringe electric field penetrating the dielectric between the two electrodes. When the volume occupancy of the dielectric between the electret and the opposing electrode varies in accordance with a displacement of the movable member, the power generation apparatus outputs the electric charge induced in the opposing electrode as electric current.