Electro-acoustic transducer e.g., microphone, for converting e.g. speech, into electrical signal, has base plate reflecting impinging sound, where light beam is modulated by sound according to frequency and amplitude of sound

摘要

The transducer has mirrors (B, C) arranged in plane parallel positions and fastened to a base plate (G). The plate reflects an impinging sound, where a light beam (D) from a pulsed light source (A) undergoes multiple reflections and is modulated by the sound according to a frequency and an amplitude of sound. The beam impinges on an opto-electric transducer having an electrical output voltage that varies in direct proportion to the progression of pressure in the sound. A light detector (E) outputs an electrical parameter, which is proportional to the intensity of light.