JPH0787608B2 - Cordless telephone - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cordless telephone.

Background Art and Its Problems In a general telephone, its telephone cord is connected to a rosette attached to a pillar or a wall. Therefore, the range in which the telephone can be moved is determined by the length of the telephone cord and is about several meters. However, if the phone cord is lengthened to increase the range of movement, the cord will become entangled or obstructed.

Therefore, in the United States and the like, a telephone system called a cordless telephone is considered.

As shown in FIG. 1, this is composed of a transceiver (1) called a handset and a transceiver (2) called a base unit, and a telephone line (3) is connected to the base unit (2). Together with the base unit (2)
The handset (1) and the handset (1) are coupled to each other by radio waves, and the reception of the telephone of the subscriber is performed for the handset (1) in the same manner as a general telephone.

Therefore, the subscriber can freely move the handset (1) when making a call, and the telephone cord is not tangled or disturbed.

The distance (service area) where the handset (1) can be separated from the base unit (2) is about 300 m. The frequency of the radio wave used between the handset (1) and the base unit (2) is 49MHz band for the up channel and 46MHz band for the down channel, and 10 duplex channels are approved by the FCC (the numerical value is Provisional value).

By the way, in some cordless telephones, a microphone and a speaker are provided in the base unit (2), and the microphone and the speaker enable communication between the base unit (2) and an outside line telephone. Further, during this call, there is one that transfers the call from the base unit (2) to the handset (1) so that the call can be made between the handset (1) and an outside line telephone.

Therefore, according to the cordless telephone having such a transfer function, for example, when a call is received from an outside line,
First, the person on the base unit (2) side received the call,
This can be transferred to a person on the handset (1) side as needed, and the cordless telephone can be used more conveniently.

However, in order to transfer the call, it is necessary to perform a fairly complicated switch operation on the base unit (2) side as shown in FIG. 2, and if the order of the switch operations is wrong, the call is transferred to the handset ( I can not be transferred to 1), or in the worst case the call is disconnected.

Also, once the call is transferred to the handset (1), the call cannot be transferred from the handset (1) to the base unit (2), so a call between the outside line telephone and the base unit (2) is required again. However, I can't do this.

OBJECT OF THE INVENTION The present invention is intended to solve such a problem.

SUMMARY OF THE INVENTION Therefore, in the present invention, a call transfer process is performed by operating one key switch, and also a call can be transferred from the handset (1) to the base unit (2). Is.

Embodiment First, the basic configuration and operation of the signal system of the handset (1) and the base unit (2) will be described. In this example, the communication channel between the handset (1) and the base unit (2) is A channel or B channel.

FIG. 3 shows an example of the handset (1), in which (110) is a transmitting circuit and (120) is a receiving circuit. FIG. 4 shows an example of the base unit (2), in which (210) is a transmitting circuit and (220) is a receiving circuit.

Then, at the time of transmission, in the handset (1), the audio signal St from the transmitter (111) is changed to the low frequency amplifier (112).
It is supplied to the FM modulation circuit (113) through and converted to the upstream A channel or B channel FM signal Su.
The FM signal Su has a high frequency power amplifier (114) and a band pass filter (11
It is supplied to the antenna (100) through 5) and transmitted to the base unit (2).

Then, in the base unit (2), the signal (radio wave) Su from the handset (1) is received by the antenna (200), and the received signal Su is a band pass filter (221) having both upstream channels as pass bands. ) And the high-frequency amplifier (222) to the mixer circuit (223), and the local oscillation circuit (224) supplies a local oscillation signal of a predetermined frequency to the mixer circuit (223) to convert the signal Su into an intermediate frequency signal. The converted intermediate frequency signal is supplied to the FM demodulation circuit (226) through the intermediate frequency amplifier (225) to demodulate the audio signal St, and the signal St is converted into the low frequency amplifier (227) → hybrid circuit (231) → Relay circuit (23
It is sent to the telephone line (3) through the signal line of 2).

In this case, the relay circuit (232) is a relay for turning on / off the connection between the base unit (2) and the telephone line (3), and temporarily holds a call after the base unit (2) and the line (3) are connected. It has a hold relay for holding the line (3) when it is interrupted.

In addition, when receiving a voice signal Sr from the telephone line (3)
Is supplied to the handset (128) of the handset (1) by the same processing as when transmitting. That is, the audio signal Sr from the line (3) is transmitted through the signal line of the relay line (232) → hybrid circuit (231) → low frequency amplifier (212).
It is supplied to the FM modulation circuit (213) and converted to the FM signal Sd of the downlink channel of the same channel as the FM signal Su.
Sd is supplied to the antenna (200) through the high frequency power amplifier (214) and the band pass filter (215) having the pass bands of both downlink channels, and is transmitted to the handset (1).

Then, in the handset (1), the signal Sd from the base unit (2) is received by the antenna (100), and the received signal Sd has a band pass filter (121) having both downlink channels as pass bands and a high frequency wave. While being supplied to the mixer circuit (123) through the amplifier (122), a local oscillation signal of a predetermined frequency is supplied from the local oscillation circuit (124) to the mixer circuit (123), and the signal Sd is an intermediate frequency signal. If the intermediate frequency signal is an intermediate frequency amplifier (12
5) is supplied to the FM demodulation circuit (126) through the audio signal Sr.
Is demodulated and this signal Sr is supplied to the handset (128) through the low frequency amplifier (127).

Further, in the handset (1), (140) indicates a control circuit for controlling a communication channel and the like. The control circuit (140) is composed of a one-chip type microcomputer. For example, (141) is a CPU for 4-bit parallel processing, (142) is a ROM in which a program is written, and (143) is RAM for work area, (144) is an input / output port.

The microcomputer (140) has a dial key (151),
The talk switch (152), intercom key (153), channel key (154) and dip switch (155) are connected. In this case, the dial key (151) is a non-lock type push switch for inputting the telephone number of the other party, and the talk switch (152) is a three-position switch for selecting the operation mode of this handset (1). When the switch (152) is the contact O, the power of the circuits other than the microcomputer (140) is turned off (OFF mode), and when the contact S, the signal Sd from the base unit (2) is on standby. The handset (1) and the base unit (2) are in a communication state (talk mode) at the contact point T, which is normally connected to the standby contact point S.

Also, the intercom key (153) is used for the handset (1).
The non-locking type push switch and the channel key (154) for calling the base unit (2) when the base unit (2) and the base unit (2) are used like an intercom are the handset (1) and the base unit (2). Communication channel with A channel or B
It is a non-lock type push switch for changing to a channel. Further, the switch (155) is for giving an identification code ID, and the outputs of these keys and the switches (151) to (155) are supplied to the microcomputer (140).

Further, (161) indicates an MSK modulation circuit, which, when supplied with the identification code ID and the dial signal DS from the microcomputer (140), converts these signals from binary signals to MSK signals Sm in the audio band. The signal Sm is supplied to the amplifier (112).

Further, (162) indicates a reception detection circuit, which is connected to the demodulation circuit (126), and which receives the signal S from the base unit (2).
The presence or absence of the signal Sd is detected by utilizing the difference in the frequency component of the output of the demodulation circuit (126) depending on the presence or absence of d, and the detection signal NSQ is supplied to the microcomputer (140).

Further, (163) indicates an MSK demodulation circuit, which is connected to the demodulation circuit (126) and demodulates the identification code ID and the like from the MSK signal Sm sent from the base unit (2). The signal is supplied to the microcomputer (140).

Further, (164) indicates a call tone forming circuit, which is controlled by the microcomputer (140) and forms a bell sound signal (ring tone signal) when a call is received. (127).

Further, a signal CH designating a channel is supplied from the microcomputer (140) to the modulation circuit (113) and the local oscillation circuit (124), and a signal TX for controlling whether or not the FM signal Su is sent is supplied to the modulation circuit ( 113). In addition, the muting signal MUTE is sent from the microcomputer (140) to the amplifier (127).
Is supplied to.

Further, in the base unit (2), (240) indicates a control circuit. The control circuit (240) is configured similarly to the control circuit (140) of the handset (1) and has the same function, and the circuit (141) of the control circuit (140).
For the circuit corresponding to ~ (144), replace the code in the 100s
The number of the 200s is attached and the explanation is omitted.

Further, the switches (253), (255) and the circuits (261) to (2
64) is also a switch (153), (155) of the handset (1)
And circuits (161) to (164), and the same applies to each signal, and therefore description thereof will be omitted. However, the forming circuit (264) forms the tone encode signal TE corresponding to the telephone number when making a call to the other party.

Further, (265) indicates a bell sound signal detection circuit, which detects a bell sound signal when the telephone is connected to the telephone line (3), and the detection signal BL is a microcomputer (240 ) Is supplied to. The line (3) is connected to a general telephone (4) through a relay circuit (232), and a control signal line is provided between the relay circuit (232) and the microcomputer (240). In addition, (266) is a buzzer for calling, and (255) is a switch of the lock type.

When making a call from the handset (1) to the other party, the following operations are performed by the microcomputers (140) and (240) according to the programs of the ROMs (142) and (242).

That is, when the talk switch (152) is set to the talk contact T, the modulation circuit (11
The sending of the FM signal Su from 3) is permitted, the unmodulated signal Su is transmitted, and then the identification code ID is taken out from the switch (155), and this code ID is converted into the MSK signal Sm by the modulation circuit (161). It is then supplied to the amplifier (112). Therefore, the identification code ID is transmitted to the base unit (2) by the FM signal Su.

Then, in the base unit (2), when the signal Su is received, the detection signal NSQ of the signal Su from the detection circuit (262).
Is obtained, the microcomputer (240) continues the identification code ID
Enter the check state of. Then, the signal Sm is extracted from the demodulation circuit (226) and the identification code I is output from the detection circuit (263).
When D is taken out, it is checked whether this code ID matches the identification code ID set in the switch (255), and if it is incorrect (from another subscriber's handset (1)), then However, when the signal is correct, the transmission of the FM signal Sd from the modulation circuit (213) is permitted by the signal TX to establish the communication channel, and the signal MUTE causes the amplifier (227) to operate. Muting is canceled.

At this time, the signal Sd is transmitted to extract the signal NSQ from the detection circuit (162) in the handset (1), which is detected by the microcomputer (140) and the muting of the amplifier (127) is detected by the signal MUTE. It will be canceled.

Then, in the handset (1), dial key (15
When 1) is operated according to the telephone number of the other party, the corresponding dial signal DS is formed by the microcomputer (140) and converted into the MSK signal Sm by the modulation circuit (161), and similarly the base unit (2) Sent to.

Then, in the base unit (2), the dial signal DS is taken out from the demodulation circuit (263), and this signal DS
Based on, the formation circuit (264) is controlled by the microcomputer (240) to form a tone encode signal TE corresponding to the telephone number of the other party, and this signal TE is passed through the amplifier (227),
Furthermore, hybrid circuit (231) and relay circuit (232)
Through the telephone line (3). Therefore, if the other party is called by this signal TE and the other party answers the call,
After that, the call becomes possible as described above.

On the other hand, when a call is received from the other party, the following operation is performed.

That is, normally, the talk switch (152) is connected to the standby contact S, but when the call comes from the other party, the bell sound signal BL is taken out from the detection circuit (265) and supplied to the microcomputer (240). , A signal TX based on this
The modulation circuit (213) permits sending of the FM signal Sd, and then the modulation circuit (261) outputs the identification code ID to the signal S.
is converted into m, and this signal Sm is supplied to the amplifier (212),
Therefore, the identification code ID is transmitted to the handset (1) by the FM signal Sd.

Then, in the handset (1), when the signal Sd is received, the signal NSQ is extracted from the detection circuit (162) and supplied to the microcomputer (140), and the microcomputer (140) enters the identification code ID check state. When the identification code ID is taken out from the demodulation circuit (163), the match between this code ID and the identification code ID set in the switch (155) is checked. If it is not correct, the subsequent processing is not performed and the standby Continue to state, but when correct, signal
The TX permits transmission of the FM signal Su from the modulation circuit (113) to establish a communication channel, and at the same time, a bell sound signal is formed in the forming circuit (164), and this signal is transmitted through the amplifier (127) to the speaker (128). ), A bell rings and a call is announced. Therefore, if the switch (152) is switched to the talk contact T, the bell sound from the speaker (128) will stop and the muting of the amplifiers (127) and (227) will be a signal thereafter.
It is canceled by MUTE and the call becomes possible as described above.

Also, when the call is received from the other party, switch (25
If 6) is on, the bell (128) sounds from the speaker (128) in the handset (1) as described above, and the buzzer (266) sounds in the base unit (2).

Then, when the handset is picked up from the telephone (4), the buzzer (266) stops ringing and the signal TX causes FM.
The transmission of the signal Sd is stopped, and the bell sound from the speaker (128) stops in the handset (1). And after that,
In the base unit (2), it is possible to talk with an outside line telephone by using the handset of the telephone set (4).

While the base unit (2) is talking to an outside line telephone, the routine (30) of the general flow chart shown in FIG. 5 transfers the call from the base unit (2) to the handset (1) in the ROM ( 242), which is executed by the microcomputer (240).

That is, it is assumed that the base unit (2) is currently talking to an external telephone. If you press the intercom key (253) during this call, the routine (3
0) starts from step (31) and then the next step (3
In 2), the relay circuit (232) is controlled and the outside line is put on hold. Then, in step (33), the base unit (2) transmits the control signal by the MSK signal Sm to the handset (1), and the handset (1 ), The bell sound is emitted from the speaker (128).

Furthermore, the processing of the CPU (241) in the base unit (2) moves to step (41), and in this step (41), it is checked whether or not there is a response from the handset (1), that is, the switch () of the handset (1). 152)
Is switched to the talk contact T, the identification code ID is transmitted from the handset (1), and this is checked. If there is a response, the process proceeds to step (42), but if there is no response, the process proceeds to step (51). ), It is checked in this step (51) whether the intercom key (253) has been pressed again after step (32),
If not, the process returns to step (33). Therefore, steps (33), (41) and (51) are repeated until there is a response from the handset (1) (and until the interm key (253) is pressed again). Keeps ringing the bell.

Then, when there is a response from the handset (1), the process proceeds to step (42), in which the telephone (4) is connected to the hybrid circuit (231) through the relay circuit (232), and thereafter, The base unit (2) enables intercom communication with the handset (1) by using the handset of the telephone (4).

Further, the processing of the CPU (241) moves to step (61) after step (42), and the processing of steps (61), (71) and (81) is repeated while the intercom call is being made. To be taken. That is, it is checked in step (61) whether or not the handset of the telephone set (4) has been hooked. Since it is not hooked during intercom communication, the process proceeds to step (71), and this step (7)
In 1), it is checked whether or not the signal Su is transmitted from the handset (1). Since the signal Su is transmitted during the intercom call, the process proceeds to step (81), and in this step (81), the intercom key is transmitted. (twenty five
It is checked whether or not 3) has been pressed again after step (42), and if it is a simple intercom call, it is not pressed, so the process returns to step (61). Therefore, the steps (61), (71), and (81) are repeated during the intercom call.

And because the intercom call was over, the telephone (4)
On-hook your handset, this is the step (61)
Is detected by the hybrid circuit (23) and the relay circuit (232) is controlled in this step (62) to release the external line hold and the hybrid circuit (23).
1) is connected to the line (3) through the relay circuit (232). Therefore, from the time of step (62), it becomes possible to talk with the handset (1) and an outside line telephone, that is,
The call with the telephone of the outside line is transferred from the base unit (2) to the handset (1).

Then, at this time, the process of the CPU (241) is step (62).
After that, the process proceeds to step (63) to end this routine (30).

Also, during an intercom call, steps (61), (7
The processings of 1) and (81) are repeated, but at this time, if the switch (152) in the handset (1) is switched to the standby contact S or the off contact O (this is the case for the handset (1)). If the signal is not transferred), the signal Su is not received by the base unit (2), so this is detected by the step (71), and the process proceeds to the step (72), in which the relay circuit (232) is transmitted. Is controlled to release the hold of the outside line, and the telephone set (4) is connected to the line (3) through the relay circuit (232). Therefore, the telephone call between the base unit (2) and the outside line can be resumed from the time of step (72).

Then, at this time, the processing of the CPU (241) is step (72).
Then, the process proceeds to step (73) to end this routine (30).

Furthermore, during an intercom call, the intercom key (253)
When is pressed, this is detected by step (81), and the process proceeds to step (82). In this step (82), the relay circuit (232) is controlled to release the external line hold and the hybrid circuit (231). ) And telephone (4)
Is connected to the line (3) through the relay circuit (232). Therefore, from the time of step (82), it becomes possible to talk between the handset (1), the base unit (2), and the outside line telephone.

Then, at this time, the processing of the CPU (241) is step (82).
After that, the routine proceeds to step (83), and this routine (30) is ended.

When steps (33), (41), and (51) are repeated, the handset (1) continues to ring the bell, but there is no response from the handset (1). To cancel the call of 1), press the intercom key (253) again. Then, this is detected by the step (51), the process proceeds to the step (52), and in this step (52), the relay circuit (232) is controlled to release the external line hold, and
Telephone (4) is line (3) through relay circuit (232)
Connected to. Therefore, the communication between the base unit (2) and the outside line telephone becomes possible again from the time of step (52). Then, this routine (30) is ended in step (53).

On the other hand, while the handset (1) is talking to an outside line telephone, since the call is transferred from the handset (1) to the base unit (2), the routine (30) shown in FIG. 5 is also stored in the ROM (142). Added, this is a microcomputer (14
It is executed by 0). However, in this case, step (3
In 3), the buzzer (266) is sounded and the step (4
The check of the response of 1) is performed off-hook of the handset of the telephone (4). Further, the step (71) is to check whether the switch (152) is switched from the talk contact T to the other contacts S and O, and the steps (51) and (81) are to check the intercom key (153).

Therefore, even in the handset (1), call transfer, resumption, and three-way call with an external telephone can be performed in the same manner as in the base unit (2).

Thus, according to the invention, during a call with an outside line telephone in the base unit (2) or the handset (1), the call can be transferred to the handset (1) or the base unit (2) or resumed. You can do or talk between three parties.

Moreover, in that case, when transferring an outside line telephone from the base unit (2) to the handset (1), as shown in FIG. 6, simply press the intercom key (253) and if there is a response from the handset (1). The telephone (4) only needs to be hooked on-hook, and the same applies when transferring from the handset (1) to the base unit (2), and the transfer operation is extremely simple. Therefore, it is possible to transfer easily and surely without making a mistake in the operation and disconnecting the call.

Furthermore, since it is possible to transfer freely between the handset (1) and the base unit (2), for example, when a call comes in from an outside line, the base unit (2) receives the call and then the call is made. Even if a call to the base unit (2) becomes necessary after being transferred to the handset (1), this can be realized, or a call between three parties can be made.

In the above description, the circuits (161) to (163), (261)
The operations of (263) to (263) can be realized by software. Further, the other party's telephone can be sent out by dial pulse.

Effect of the Invention During a call with an outside line telephone in the cordless telephone, the call is made by the handset (1) and the base unit (2).
Either of them can be transferred to the other. Moreover, the transfer can be performed simply by operating one intercom key, and the transfer can be surely performed. In addition, a call between three parties and resumption can be easily performed.

[Brief description of drawings]

1, 2, 5, and 6 are diagrams for explaining the present invention, and FIGS. 3 and 4 are system diagrams of an example of the present invention. (1) is the handset, (2) is the base unit, (11
0) and (210) are transmitting circuits, (120) and (220) are receiving circuits, and (140) and (240) are microcomputers.

Claims (1)

[Claims] 1. A cordless telephone having a handset and a base unit connected to a telephone line, wherein communication between the handset and the base unit is performed by radio waves. In each of the handset and the base unit, ,
A call line control circuit, an on-hook detection circuit, a call signal detection circuit from the other party, and a switching key are provided, and when one of the handset and the base unit is talking to an outside line telephone, the one switching When the key is operated, the outside line is suspended by the control of the control circuit of the base unit, and the intercom call signal is transmitted from the one to the other of the handset and the base unit to call the other. After this call, when the intercom response signal from the other is detected in the one control circuit, the intercom call line that enables a call as an intercom between the one and the other is set, and the outside line hold state is set. While setting up the intercom call line of
When either one of the above-mentioned handset and the above base unit is detected to be on-hook by any one of the above-mentioned on-hook detection circuits, the control circuit of this on-hook handset or base unit controls the other one in the intercom communication line. When the other of the above-mentioned call signal detection circuits detects that the call signal from the above one has disappeared,
When this detection output is transmitted to the control circuit of the base unit, and when this detection output is transmitted to the control circuit of the base unit, the held outside line is connected to the other that has detected that the call signal has disappeared. While connecting to enable an outside line call, while setting the intercom call line in the above outside line hold state,
By operating the one switching key, the control circuit of the base unit releases the suspension of the outside line,
A cordless telephone that controls so that a three-way call can be made between the handset, the base unit, and the outside line.