JP3026529B2 - Cordless telephone - Google Patents

Abstract

PURPOSE:To always use a cordless telephone set even when any equipment to always transmit the same noise frequency as a control channel signal is existent by performing control by means of intermittently transmitting/receiving plural frequencies as the control channel signals. CONSTITUTION:When a mobile equipment 3 receives the control signal with a control channel circuit 9 and responds to it, a calling signal is sent from a control channel circuit 5, after the mobile equipment 3 receives this signal and confirms the ID, a speech channel is confirmed, a bell 12 is rung, and the speaking operation is performed by offhook. When the both frequencies or either of the frequencies are/is detected, an intermi detection circuit 15 investigates whether the interval of incoming output signals is any value decided in advance or not and when they are coincident, the detecting operation is continue until the time-out. When they are discordant within the detecting operation period of time, the control channel signals are sent from oscillation circuits 5a and 5a' inside the control channel circuit 5 through an antenna 7, and the connection with the mobile equipment 3 is operated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless telephone, and more particularly to a cordless telephone that can be expected to operate stably even when a noise source having the same frequency as a control channel is present in the vicinity.

[0002]

2. Description of the Related Art The use of cordless telephones tends to increase because of the convenience of being able to talk while moving indoors. However, in order to use a limited radio frequency band, measures have been taken to prevent interference with other cordless telephones.

FIG. 2 is a diagram for explaining an incoming call operation of a conventional cordless telephone. Reference numeral 21 denotes a line, 22 denotes a connection device connected to the line 21, 23 denotes a mobile unit that performs a call while moving, 24 Is an IR detector for detecting a call signal from the exchange, 25 is a control channel circuit comprising a transmitter and a signal detector when performing a connection operation with the mobile device 23, 26 is a voice signal between the mobile device 23 A communication channel circuit for transmitting and receiving data; 27, an antenna of a connection device; 28, an antenna of a mobile device 23;
Reference numeral 3 denotes a control channel circuit, reference numeral 30 denotes a communication channel circuit of the mobile device 23, reference numeral 31 denotes a handset, and reference numeral 32 denotes a bell circuit. Hereinafter, an operation sequence of a conventional cordless telephone will be described with an example of an incoming call operation.

[0004] When a call signal from the exchange arrives via the line 21, the IR detector 22 detects the signal.
At this time, the connection device 22 does not send a signal indicating that there is an incoming call to the mobile device 23, but determines whether or not another cordless telephone nearby is performing a call operation. 27, a signal of about 250 MHz, which is a control channel signal of the mobile station 23, is detected.

[0005] This operation is for preventing interference with other cordless telephones. The control channel circuit 25 transmits the control channel signal of about 250 M
If the signal of the frequency band is not detected, it is determined that another nearby cordless telephone is on standby and the control channel circuit 25
Transmits a control signal via the antenna 27.

Thereafter, a call signal is transmitted from the control channel circuit 25 via the antenna 27, and after the mobile station 23 receives this signal and performs ID confirmation and the like, the communication channel is confirmed and the bell of the bell circuit 32 rings. Then, when the user goes off-hook on the mobile device, a call operation is performed by the handset 31.

On the other hand, when the control channel circuit 25 detects a signal of about 250 MHz, which is a control channel signal, it determines that it is based on another cordless telephone, and
Until the control channel operation elapses about 200 msec, the connection device 22 does not transmit a signal indicating that there is an incoming call to the mobile device 23. The standby time of the connection device 22 is about 4 seconds, and the control channel operation of the other cordless telephone is completed within about 4 seconds, so that no problem occurs in the call operation.

[0008]

The connection operation of a normal cordless telephone is performed as described above.
If there is an electrical device such as a facsimile or a personal computer that constantly emits a noise radio wave of about 250 MHz, which is a control channel signal of the mobile device 23, even if it is weak, the control of other cordless telephones may occur. The connection operation is not performed because it is erroneously recognized as a channel signal. Therefore, even if there is an incoming call to the connection device 22, the connection operation is not performed, and the bell of the mobile device does not ring. On the other hand, since the connection device 22 is operating normally up to the caller, a ringing tone is sent from the exchange. Therefore, the caller determines that the other party is absent and goes on-hook.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages of the related art, and to provide a cordless telephone capable of operating normally even if the same noise frequency as the control channel exists near the cordless telephone. It is an object.

[0010]

According to the present invention, the above-mentioned object is solved by the means described in the claims.

That is, the present invention provides a transmitter for transmitting control signals of a plurality of different frequencies to a connection device of a cordless telephone and a mobile device, and discriminates a frequency by receiving a control signal of a plurality of frequencies. And a timer for specifying an output interval of the transmission circuit, means for intermittently transmitting a control signal at a constant interval from a plurality of control channels, and an interval of a reception frequency coincides with the interval of the timer. An intermittent detection circuit for determining whether or not to perform the operation, and at least one control signal is detected in pre-processing at the time of calling / incoming, and when the control signal does not match the interval of the timer, or for a certain time even if it does. A cordless telephone provided with the connection device and a means for connecting a mobile device when the connection does not match later.

[0012]

FIG. 1 shows an embodiment of the present invention.
1 is a line 2 is a connection device, 3 is a mobile device, 4 is an IR detector,
5, 9 are control channel circuits, 6, 10 are communication channel circuits, 7, 8 are antennas, 11 is a handset, 13, 14 are timers for transmitting control channel signals intermittently, 1
Reference numerals 5 and 16 denote intermittent detection circuits for determining whether or not a signal arrives at a correct interval when the control channel signal is received, that is, at intervals of the timers 13 and 14.

The control channel circuit 5 of the connection device 2 includes a transmitting circuit 5a for transmitting one of a plurality of control channel signals having different frequencies, and a receiving circuit for receiving one of a plurality of control channel signals having different frequencies. The circuit 5b and the other control channel signal transmitting circuit 5a 'are composed of another control channel signal receiving circuit 5b'. The control channel circuit 9 of the mobile station 3 is provided with a control channel signal among a plurality of control channel signals having different frequencies. 1
A transmission circuit 9a for transmitting one of the control channel signals, a reception circuit 9b for receiving one of the plurality of control channel signals, a transmission circuit 9a 'for another control channel signal, and a reception circuit 9b' for another control channel signal.

Hereinafter, the operation of the embodiment will be described by taking the case of an incoming call operation as an example.

When a call signal from the exchange arrives via the line 1, the IR detector 2 detects the signal. At this time, the connection device 2 does not immediately transmit a signal indicating that there is an incoming call to the mobile device 3, but determines whether or not another cordless telephone nearby is performing a transmission operation. 7, a plurality of frequencies as control channel signals of the mobile station 3 are received by the receiving circuits 5b and 5b '.

Each of the receiving circuits 5b and 5b 'detects only a control channel signal having a predetermined frequency. The predetermined frequency is the aforementioned 250M
Different frequencies such as Hz and 260 MHz are used. If neither or one of the frequencies is detected, it is determined that another nearby cordless telephone is on standby, and the transmitting circuits 5a and 5a 'in the control channel circuit 5 transmit the antenna 7
Via the control signal.

When the mobile station 3 receives the signal in the control channel circuit 9 and responds, a call signal is transmitted from the control channel circuit 5 via the antenna 7, and the mobile station 3 receives this signal and confirms ID or the like. After the call, the call channel is confirmed, the bell 12 rings, and the user off-hooks the mobile device, so that a call operation is performed by the handset.

When both or one of the frequencies is detected, the output signal is sent to the intermittent detection circuit 15. The intermittent detection circuit 15 checks whether or not the interval between the arriving output signals has a predetermined value. If the intervals match, the detection operation is continued until timeout (for example, for 4 seconds). If the signal does not match within the detection operation time, a control channel signal is transmitted from the transmission circuits 5a and 5a 'in the control channel circuit 5 via the antenna 7, and the connection operation with the mobile station 3 is performed.

When both or one of the frequencies is detected, and the output signal thereof is checked by the intermittent detection circuit 15, if it is other than a predetermined interval value,
It is determined that the noise is ambient environmental noise, and the process proceeds to a connection operation with the mobile device 3.

The transmission operation is an operation in the reverse direction,
Since the same operation is performed from the mobile device 3 to the connection device 2, the description is omitted.

[0021]

As described above, according to the present invention, a cordless telephone is controlled by a method of intermittently transmitting and receiving a plurality of frequencies as a control channel signal. Therefore, even if there is a device near the connection device or the mobile device that constantly emits the same noise frequency as the control channel signal, it can be used normally since it can be distinguished from control of the cordless telephone.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram for explaining an incoming call operation of a conventional cordless telephone.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 line 2 connection device 3 mobile device 4 IR detector 5, 9 control channel circuit 5 a, 5 a ′, 9 a, 9 a ′ transmission circuit 5 b, 5 b ′, 5 b, 5 b ′ reception circuit 6, 10 communication channel circuit 7, 8 antenna 11 Handset 13, 14 Timer 15, 16 Intermittent detection circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 102 H04Q ^7/ 00-7/38

Claims (1)

(57) [Claims] A connection device for a cordless telephone, and
A transmitting circuit capable of transmitting control signals of a plurality of different frequencies to a mobile device, a receiving circuit for receiving control signals of a plurality of frequencies and performing frequency discrimination, and for specifying an output interval of the transmitting circuit A timer, means for intermittently sending control signals from the plurality of control channels at regular intervals, an intermittent detection circuit for judging whether or not the interval of the reception frequency matches the interval of the timer, At least one control signal is detected during the pre-processing, and when the control signal does not match the interval of the timer, or when the control signal does not match after a certain period of time, the connection device is connected to the mobile device. And a means for providing a cordless telephone.