| 摘要 |
PURPOSE:To prevent the third person from using a telephone set by decoding a user's characteristic number that is set prior to origination. CONSTITUTION:A number, once inputted from dial 14, converted by keyboard deciphering circuit 16 into a fixed code, which is stored in memory circuit 18. The output of this circuit 18 is compared to the contents of characteristic memories 19-21 of comparators 22-24. When the dialed characteristic number agrees with the contents of memory 19, one of FFs 25-27 is set and central processing circuit 28 is informed of the identity. After the information, circuit 28 resets circuit 18. In accordance with states of FFs 25-27, circuit 28 limits a dialing available area with regard to a call following the characteristic-number input operation. Thus, while the third person is inhibited from using the telephone set, indivicual services can be offered to many users. |
