| 摘要 |
PURPOSE:To enhance the S/N by giving the blinking to the light emitting element in a high frequency and via the oscillator. CONSTITUTION:The blinking is given to light emitting element 304 by oscillator 309 and in a high frequency (several hundreds kHz-several MHz). Under these conditions, part of the light reflected by oscillating film 301 enters optical fiber 303, and this incident light is obtained in the form of the optical signal which is modulated by the sound pressure and in a certain frequency. As a result, the effect of the low frequency noise of each element, the external noise and others can be avoided easily, thus enhancing the S/N finally. |
