| 摘要 |
PURPOSE: To avoid the trouble due to the existence or a cord to enable a rider to safely drive his motorcycle by performing transmission/reception between a microphone with a receiver and a radio machine through infrared rays to eliminate a need of the cord connecting both of them. CONSTITUTION: The voice of the motorcycle rider is picked up as bone- conduction tone by an ear microphone and is inputted to the transmission circuit of a first light emitting optical unit. It is emitted from a light emitting element 7 as, for example, 2.3MHz FM wave. These infrared rays are received by a light receiving element in a second light receiving optical unit on the motorcycle side and are demodulated and are inputted to the AF line of the radio machine. Transmission from the radio machine is started by the start of the voice or rider's switch operation. The tone received by the radio machine is received as the FM wave modulated to, for example, 2.8MHz by the light receiving element in the second light receiving optical unit and is emitted from the receiver in the ear microphone after demodulation. |
