Shinnosuke Taniishi

Acoustic output device and electronic apparatus using the acoustic output device

Sound waves from a plate-shaped acoustic source, which generates fundamental waves (sound waves) having at least two frequencies, propagate through a propagating portion. The propagating portion consists of a medium in which a non-linear interaction is induced by the fundamental waves. A secondary sound wave having a frequency conforming to the difference between the two fundamental waves is generated by the medium. Fundamental wave components other than the secondary sound wave are absorbed by an acoustic absorber so that only the secondary sound wave is delivered as an output. The acoustic source, propagating portion and acoustic absorber are substantially transparent and stacked in three layers. This allows the resulting acoustic output device to be incorporated in the display unit of an electronic apparatus.

Acoustic coordinate input device using a roughened surface to attenuate the surface wave component

A coordinates input device comprises vibration means for generating vibration, a pin having an end to which the vibration generated by said vibration means is transmitted, and a vibration transmission plate having a roughened surface or resin coating on a pen abutment surface thereof, for transmitting the vibration.

Lamb Wave and its Application to a Digitizer

An anti-symmetric mode Lamb wave with different phase velocity Vp and group velocity Vg has been studied. An algorithm for accurate measurement of the distance between two points is established using Lamb wave of low frequency and measuring both phase delay time Tp and group delay time Tg.