PURPOSE: To obtain a wrist watch which has a selective calling system without new facilities and applying a legal procedure, by utilizing an existent broadcasting network.
CONSTITUTION: The output of a private broadcasting device 201 is connected through cables 210 to respective loud speakers in private broadcasting networks 217 and 218 in respective buildings and rooms. When a calling subscriber calls an operator from an extension telephone to tell a called subscriber, the operator sets an input signal changeover switch 209 and inputs the called-subscriber's number. This number is displayed on a display 206 and a transmission button 205 is then operated to send a modulated signal from a broadcasting device 209 to the loud speakers of respective rooms. A call signal from each loud speaker is received by the microphone 304 of the wrist watch 301 that the called subscriber carries to discriminate the signal, obtaining information 307 on the reception of the call signal.
TAKAGI MICHIAKI
HAMA TERUYASU
KOGURE SHIGERU
| JPS5320366A | 1978-02-24 | |||
| JPS4860984A | 1973-08-27 | |||
| JPS5437517A | 1979-03-20 | |||
| JP54038420B | ||||
| JPS5535515A | 1980-03-12 |