| 摘要 |
<p>PURPOSE:To provide an ultrasonic learning device where the surface of a non- piezoelectric substrate provided with an ultrasonic transmission/reception means and a display screen is touched with a finger, a material, or a spot of laser light to input and display the learning information. CONSTITUTION:When a linear chirp signal having a frequency band DELTAf1-1 or DELTAf1-2 is inputted from an interdigital electrode for input, the electric signal having the frequency which is changed in accordance with the electrode period length of the interdigital electrode for input is converted to a surface acoustic wave and is propagated in a non-piezoelectric substrate 7, and the surface acoustic wave whose wavelength is approximately equal to the electrode period length of an interdigital electrode for output is converted to a delay electric signal, and this signal is outputted. When the propagation path of the surface acoustic wave on the non-piezoelectric substrate 7 is touched, the delay electric signal is attenuated by this touch. The touch position is detected by the frequency of the attenuated delay electric signal. Information in colors different by frequency bands of the input signal is displayed on the display screen in a form corresponding to the touch position in accordance with the frequency band of the input signal.</p> |
