Cordless telephone system

Claim 2

A cordless telephone system comprising a radio telephone set and a connection unit connected to a wire telephone circuit and also connected through a radio communication circuit to said radio telephone set, for performing interconnection control between said wire telephone circuit and said radio telephone set, characterized in that there are provided: transmission means provided in said connection unit, for sending a disconnecting signal from the connection unit to said radio telephone set to cut off said raido communication circuit when a signal on the radio communication circuit is put in an unreceivable state; and disconnection means provided in said radio telephone set, for forcibly cutting off said radio communication circuit when said disconnection means receives said disconnect signal.

Claim 3

A cordless telephone system as set forth in claim 1, wherein said transmission means transmits said disconnect signal when a received electric field of said radio communication circuit is reduced to a predetermined level or less.

Claim 4

A cordless telephone system as set forth in claim 1, wherein said transmission means transmits said disconnect signal when the received electric field of said radio communication circuit is reduced to a predetermined level or less and kept at said level continuously for a predetermined time or more.

Claim 5

A cordless telephone system comprising a radio telephone set and a connection unit connected to a wire telephone circuit and also connected through a radio communication circuit to said radio telephone set, for performing interconnection control between said wire telephone circuit and said radio telephone set, characterized in that there are provided: first transmission means provided in said radio telephone set, for sending a first disconnecting signal from said radio telephone set to the connection unit when a signal on the radio communication circuit is put in an unreceivable state; second transmission means provided in said connection unit, for sending a second disconnect signal from said connection unit to said radio telephone set when the signal on the radio communication circuit is put in an unreceivable state; first disconnection means provided in said connection unit, for forcibly cutting off said radio communication circuit when said first disconnection means receives said first disconnect signal; and second disconnection means provided in said radio telephone set, for forcibly cutting off said radio communication circuit when said second disconnection means receives said second disconnect signal.

Claim 6

A cordless telephone system comprising a radio telephone set and a connection unit connected to a wire telephone circuit and also connected through a radio communication circuit to said radio telephone set, for performing interconnection control between said wire telephone circuit and said radio telephone set, characterized in that there are provided: first transmission means provided in said radio telephone set, for sending a first disconnecting signal from said radio telephone set to the connection unit when a signal on the radio communication circuit is put in an unreceivable state; second transmission means provided in said connection unit, for sending a second disconnect signal from said connection unit to said radio telephone set when the signal on the radio communication circuit is put in an unreceivable state; first disconnection means provided in said connection unit, for forcibly cutting off said radio communication circuit when said first disconnection means receives said first disconnect signal; and second disconnection means provided in said radio telephone set, for forcibly cutting off said radio communication circuit when said second disconnection means receives said second disconnect signal.

Claim 7

A cordless telephone system as set forth in claim 4, wherein said first disconnection means generates said first disconnect signal when a received electric field of said radio communication circuit is reduced to a first predetermined level or less, said second disconnection means generates said second disconnect signal when the received electric field of said radio communication circuit is reduced to a second predtermined level or less, said first predetermined level being set to be larger than said second predetermined level.

Claim 8

A cordless telephone system as set forth in claim 4, wherein said first disconnection means generates said first disconnect signal when the received electric field of said radio communication circuit is reduced to said first predetermined level or less and kept at said level continuously for a first set time or more, and said second disconnection means generates said second disconnect signal when the received electric field of said radio communication circuit is reduced to said second predtermined level or less and kept at said level continuously for a second set time or more, said first predetermined level being set to be larger than said second predetermined level, said first set time being set to be larger than said second set time.

Claim 9

A cordless telephone system comprising a radio telephone set and a connection unit connected to a wire telephone circuit and also connected through a radio communication circuit to said radio telephone set, for performing interconnection control between said wire telephone circuit and said radio telephone set, characterized in that there are provided: first transmission means provided in said radio telephone set, for sending a first disconnect signal from said radio telephone set to the connection unit when a signal on the radio communication circuit is put in an unreceivable state; second transmission means provided in said connection unit, for sending an alarm signal from said connection unit to said radio telephone set when the signal on the radio communication circuit is put in a first unreceivable state and for sending a second disconnect signal when said signal on the radio communication circuit is put in a second unreceivable state; first disconnection means provided in said connection unit for forcibly cutting off said radio communication circuit when said first disconnection means receives said first disconnect signal; means provided in said radio telephone set, for generating an alarm when receiving said alarm signal; and second disconnection means provided in said radio telephone set, for forcingly cutting off said radio communication circuit when said second disconnection means receives said second disconnect signal.

Claim 10

A cordless telephone system comprising a radio telephone set and a connection unit connected to a wire telephone circuit and also connected through a radio communication circuit to said radio telephone set, for performing interconnection control between said wire telephone circuit and said radio telephone set, characterized in that there are provided: first transmission means provided in said radio telephone set, for sending a first disconnect signal from said radio telephone set to the connection unit when a signal on the radio communication circuit is put in an unreceivable state; second transmission means provided in said connection unit, for sending an alarm signal from said connection unit to said radio telephone set when the signal on the radio communication circuit is put in a first unreceivable state and for sending a second disconnect signal when said signal on the radio communication circuit is put in a second unreceivable state; first disconnection means provided in said connection unit for forcibly cutting off said radio communication circuit when said first disconnection means receives said first disconnect signal; means provided in said radio telephone set, for generating an alarm when receiving said alarm signal; and second disconnection means provided in said radio telephone set, for forcingly cutting off said radio communication circuit when said second disconnection means receives said second disconnect signal.

Claim 11

A cordless telephone system as set forth in claim 7, wherein said first disconnection means generates said first disconnect signal when a received electric field of said radio communication circuit is reduced to a first predetermined level or less, said second disconnection means includes means for generating an alarm signal when the received electric field of said radio communication circuit is reduced to a second predetermined level or less and also includes means for generateing said second disconnect signal when the received electric field is reduced to a third predetermined level or less, said first predetermined level being set to be larger than said second predetermined level, said second predetermined level being set to be smallr than said third predetermined level.

Claim 12

A cordless telephone system as set forth in claim 7, wherein said first disconnection means generates said first disconnect signal when when the received electric field of said radio communication circuit is reduced to said first predetermined level or less and kept at said level continuously for a first set time or more, said second disconnection means includes alarm means for generating an alarm signal when when the received electric field of said radio communication circuit is reduced to said second predtermined level or less and kept at said level continuously for a second set time or more and also includes means for generating said second disconnect signal when the received electric field of said radio communication circuit is reduced to said second predetermined level or less and kept at said level continuously for a third set time or more, said first predetermined level being set to be larger than said second predetermined level, said first set time being set to be larger than said second set time, said second set time being set to be smaller than said third set time.

Claim 13

A cordless telephone system as set forth in claim 9, wherein said alarm means generates said alarm signal when the received electric field of said radio communication circuit is reduced to said first predetermined level or less and kept at the said level continuously for a fourth set time or more.

Claim 14

A cordless telephone system comprising a radio telephone set and a connection unit connected to a wire telephone circuit and also connected through a radio communication circuit to said radio telephone set, for performing interconnection control between said wire telephone circuit and said radio telephone set, characterized in that there are provided: transmission means provided in said connection unit for sending a disconnect signal for the connection unit to said radio telephone set to cut off said raido communication circuit when said wire telephone circuit is put in an unusable state; and disconnection means provided in said radio telephone set for forcibly cutting off said radio communication circuit when said disconnection means receives said disconnect signal.

Claim 15

A cordless telephone system comprising a radio telephone set and a connection unit connected to a wire telephone circuit and also connected through a radio communication circuit to said radio telephone set, for performing interconnection control between said wire telephone circuit and said radio telephone set, characterized in that there are provided: transmission means provided in said connection unit for sending a disconnect signal for the connection unit to said radio telephone set to cut off said raido communication circuit when said wire telephone circuit is put in an unusable state; and disconnection means provided in said radio telephone set for forcibly cutting off said radio communication circuit when said disconnection means receives said disconnect signal.

Claim 16

A cordless telephone system as set forth in claim 11, wherein said connection unit has a wire telephone set and said transmission means transmits said disconnect signal when said wire telephone circuit is connected to said wire telephone set.

Claim 17

A cordless telephone system comprising a radio telephone set, a connection unit connected to a wire telephone circuit and also connected through a radio communication circuit to said radio telephone set, for performing interconnection control between said wire telephone circuit and said radio telephone set, and a wire telephone set provided in said connection unit, characterized in that there are provided: first transmission means provided in said radio telephone set, for sending a first disconnect signal from said radio telephone set to the connection unit to cut off said raido communication circuit when a signal on the radio communication circuit is put in an unreceivable state or when said wire telephone circuit is connected to said wire telephone set; second transmission means provided in said connection unit, for sending a second disconnect signal from said connection unit to radio telephone set to cut off said raido communication circuit when the signal on the radio communication circuit is put in an unreceivable state; first disconnection means provided in said connection unit, for forcibly cutting off said radio communication circuit when said first disconnection means receives said first disconnect signal; and second disconnection means provided in said radio telephone set for forcibly cutting off said radio communication circuit when said second disconnection means receives said second disconnect signal.

Claim 18

A cordless telephone system comprising a radio telephone set, a connection unit connected to a wire telephone circuit and also connected through a radio communication circuit to said radio telephone set, for performing interconnection control between said wire telephone circuit and said radio telephone set, and a wire telephone set provided in said connection unit, characterized in that there are provided: first transmission means provided in said radio telephone set, for sending a first disconnect signal from said radio telephone set to the connection unit to cut off said raido communication circuit when a signal on the radio communication circuit is put in an unreceivable state or when said wire telephone circuit is connected to said wire telephone set; second transmission means provided in said connection unit, for sending a second disconnect signal from said connection unit to radio telephone set to cut off said raido communication circuit when the signal on the radio communication circuit is put in an unreceivable state; first disconnection means provided in said connection unit, for forcibly cutting off said radio communication circuit when said first disconnection means receives said first disconnect signal; and second disconnection means provided in said radio telephone set for forcibly cutting off said radio communication circuit when said second disconnection means receives said second disconnect signal.

Claim 19

A cordless telephone system as set forth in claim 13, wherein said first disconnection means generates said first disconnect signal when a received electric field of said radio communication circuit is reduced to a first predetermined level or less, said second disconnection means generates said second disconnect signal when the received electric field of said radio communication circuit is reduced to a second predetermined level or less, said first predetermined level being set to be larger than said second predetermined level.

Claim 20

A cordless telephone system as set forth in claim 13, wherein said first disconnection means generates said first disconnect signal when the received electric field of said radio communication circuit is reduced to said first predetermined level or less and kept at said level continuously for a first set time or more, said second disconnection means generates said second disconnect signal when the received electric field of said radio communication circuit is reduced to said second predetermined level or less and kept at said level continuously for a second set time or more, said first predetermined level being set to be larger than said second predetermined level, said first set time being set to be larger than said second set time.