| 摘要 |
PURPOSE:To improve reliability for transmission, by inputting an individual selection call signal and a voice signal outputted from an individual selection call apparatus from a microphone, and transmitting those signals after modulating. CONSTITUTION:The individual selection call signal with a selected frequency is outputted from the speaker 14d of the individual selection call apparatus 14 as a sound wave. The signal is inputted from the microphone 3a to a transmitter 3 with the voice signal, and after being modulated by the transmitter 3, is transmitted from a transmission antenna 6. In other words, the individual selection call signal is inputted to the transmitter 3 as the sound wave, therefore, it is not required to connect the transmitter 3 to the apparatus 4 mutually with a signal line. Thereby, no problem exists in the difference of the kind of device or the attachment of form qualification, and also. imperfect connection is out of question, then, the reliability for the transmission can be improved. |
