Telephone system

Claim 2

A telephone system characterized by comprising: a plurality of telephones (20) each assigned with a telephone number and provided with input means (16, 18) for inputting a personal ID number of a person who wants to use the telephone; and exchange means (10) including a reference table means for storing data representing the telephone num­bers and the personal ID numbers, and means of con­necting any calling telephone to a called telephone in accordance with the data stored in the reference table means.

Claim 3

The telephone system according to claim 1, characterized in that said input means includes means (16) for reading a personal ID number from a first memory means (18) storing the personal ID number.

Claim 4

The telephone system according to claim 2, characterized in that said first memory means (18) is an IC card device containing a semiconductor IC chip (18A) storing the personal ID number.

Claim 5

The telephone system according to claim 1, characterized in that said reference table means (7) has a second memory means for storing the numbers of said telephones and the personal ID numbers associated with these telephone numbers, respectively.

Claim 6

The telephone system according to claim 4, characterized by further comprising means (4) for enabling said second memory means to store a personal ID number when this personal ID number is input from said input means (16, 18).

Claim 7

The telephone system according to claim 5, characterized in that said exchange means (10) further includes: detecting means (4) for detecting whether or not said second memory means stores a personal ID number identical to the personal ID number input from said input means; means (4) for clearing the personal ID number stored in said second memory means (7) when said detect­ing means detects that this personal ID number is iden­tical to the personal ID number input from said input means; and means (4) for writing the personal ID number input from said input means, into an area of said second memory means (7) which is assigned to the number of the telephone having said input means.

Claim 8

The telephone system according to claim 6, characterized in that each of said telephones (20) has means (12, 14) for setting the telephone in a dial-in mode when the personal ID number input from said input means is written into said second memory means, so that the telephone is connected to a calling telephone on which the personal ID number is dialed.

Claim 9

The telephone system according to claim 4, characterized in that said reference table means (7) further includes a third memory means for storing per­sonal ID numbers in association with telephone numbers, said exchange means (10) further includes date-change detecting means (4a) for detecting changes of dates, and control means (4) for clearing the data stored in said second memory means when said date-change detecting means (4a) detects a change of date.