| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an acoustoelectric transducer that can reproduce sound with high S/N. SOLUTION: The acoustoelectric transducer provided with a diaphragm vibrated by sound, a light emitting element that makes light incident onto the diaphragm, a photodetector that transducers a displacement of the diaphragm by sound into a change in an electric signal and provides an output, and a lens element that converges the incident light from the light emitting element and leads the converged light to the diaphragm, converges a divergent reflecting light from the diaphragm between a 1st focal position and a 2nd focal position on an optical axis and leads the converged light to the light receiving element, is provided with a shade means that shades part of the divergent reflecting light converged between the 1st focal position and the 2nd focal position.</p> |
