Microphone

摘要

A microphone uses an infrared light emitting element and an infrared light receiving element as a proximity sensor. The microphone can avoid the adverse effect of disturbing light without the need for a special optical filter to enable a person (speaker) to be reliably sensed. The microphone includes a microphone unit which converts a sound wave into an electric signal to output the signal from a microphone output section 151 , and a proximity sensor. An output signal from the proximity sensor controllably turns on and off the microphone output section 151 . The proximity sensor includes an infrared light receiving element 131 tuned only to a particular frequency to output a light reception signal and infrared light emitting elements 121 and 122 which emit infrared rays at the frequency to which the infrared light receiving element is tuned.