| 摘要 |
PURPOSE:To simplify the constitution of a telephone set without providing an electric circuit supplying a side tone, by connecting a transmitter and a receiver each other with a handset case so as to have an acoustic gap between them, and transmitting tone to the receiver mouth via a hollow part formed at the grip part of a handset. CONSTITUTION:Both a transmitter T and a receiver R are set into both end parts of a handset case H, and a gap G is formed between these T and R and the case H. Thus the tone transmitted from the T reaches the speaker's ear through the gap G at the side of the R and via a hollow part at the grip part of the H. At the same time, a sound stopper ST having a spring SP is set at the grip part in order to control the side tone. As a result, the side tone can be received with a simple constitution and without providing an electric circuit to a telephone set supplying the side tone. |
