JPH0683137B2 - 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 calling, 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, even a cordless telephone capable of this transfer cannot make a call between the handset (1), the base unit (2), and the outside line telephone.

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

SUMMARY OF THE INVENTION Therefore, in the present invention, the operation of one key switch enables communication between an outside telephone, a handset (1), and a base unit (2). .

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. 2 shows an example of the handset (1), in which (110) is a transmitting circuit and (120) is a receiving circuit. FIG. 3 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 hand 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 to an intermediate frequency. The intermediate frequency signal is supplied to the FM demodulation circuit (226) through the intermediate frequency amplifier (225) to demodulate the audio signal St, and this signal St is converted to the low frequency amplifier (22
7) → Hybrid circuit (231) → It is sent to the telephone line (3) through the signal line of the relay circuit (232).

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) It is supplied to the MF 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 the 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) represents an MFS modulation circuit, which converts a corresponding control signal into an MSK signal Sm in the audio band when a key or switch (151) to (155) is operated. When the identification code ID and the dial signal DS are supplied from the microcomputer (140), these signals are converted from the binary signal to the MSK signal Sm. And that signal S
m 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 the circuits (161) to (164) and the same for each signal, and thus 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) represents a bell sound signal detection circuit, which detects a bell sound signal when a call is received by being connected to the telephone line (3), and the detection signal BL is a myco (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 from the FM signal Su to the base unit (2).

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, it becomes possible to make a call 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).

During the call with the telephone of the outside line in the base unit (2), the routine (30) of the general flow chart shown in FIG. 4 has the ROM (242) in order to enable the call with the handset (1). , 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), a control signal by the MSK signal Sm is transmitted from the base unit (2) 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). The sound continues to ring.

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) following step (42), and while the intercom call is being performed, the processing of steps (61), (71), (81) and (91) is performed. The process is repeated. That is, in step (61), it is checked whether or not the handset of the telephone set (4) has been hooked, and since it has not been hooked during the intercom call, the process proceeds to step (71), and in this step (71). It is checked whether or not the signal Su is transmitted from the handset (1), and the signal Su is transmitted during the intercom call, so the process is the step (81).
Then, in this step (81), it is checked whether or not the intercom key (253) is pressed again after the step (42). If it is a simple intercom call, the intercom key (253) is not pressed. Therefore, the process proceeds to step (91). In step (91), it is checked whether or not the intercom key (153) of the handset (1) has been pressed. If the intercom call is not being performed, the intercom key (153) is not pressed. Therefore, the process returns to step (61). Therefore, the steps (61), (71), (81), and (91) 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 processes 1) and (81) are repeated, but at this time, if the switch (152) in the band set (1) is switched to the standby contact S or the off contact O (this goes to the handset (1). Signal is not received by the base unit (2), it 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 the intercom call, with the handset (1),
When it becomes necessary to talk between the base unit (2) and the outside line telephone, the intercom key (253) or (153) is pressed.

That is, for example, if you press the intercom key (253),
This is detected in step (81), and the process proceeds to step (82). In this step (82), the relay circuit (232) is controlled to release the outside line, and
The hybrid circuit (231) and the telephone (4) are connected to the line (3) through the relay circuit (232). Therefore,
From the time of step (82), a call can be made among the three parties, the handset (1), the base unit (2) and the outside line.

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 the intercom key (153) is pressed during the intercom call, this is detected by the step (91), and the process proceeds to the step (92). In this step (92), the relay circuit (232) is controlled and the external line is connected. The hold is released, and the hybrid circuit (231) and the telephone (4) are connected to the line (3) through the relay circuit (232).
Therefore, from the time of step (92), the handset (1)
It becomes possible to talk between the base unit (2) and the outside line telephone.

Then, at this time, the process of the CPU (241) is step (92).
Then, the process proceeds to step (93) to end this routine (30).

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 in step (51), the process proceeds to step (52), in which the relay circuit (232) is controlled to release the outside 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, in order to enable the telephone call with the base unit (2) during a telephone call with an outside line in the handset (1), the routine (30) shown in FIG.
42), which is executed by the microcomputer (140). However, in this case, the buzzer (266) is sounded in step (33), and the response check in step (41) 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 step (51) is 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 present invention, while the base unit (2) or the handset (1) is talking to an outside line telephone, the call is made to the outside line telephone and the handset (1).
It can be performed among three parties with the base unit (2).

Moreover, in that case, an outside line telephone and a base unit (2)
Then, when talking between the three parties with the Hadset (1), simply press the intercom key (253) on the base unit (2) as shown in FIG. 5 and if there is a response from the handset (1). Intercom key again (25
You just have to press 3) and the same applies when transferring from the handset (1) to the base unit (2).
It is extremely easy to operate a call between persons. Therefore, it is possible to easily and surely make a three-party call without making a mistake in the operation and disconnecting the call.

Further, in the case of this example, a three-party call can be made from either the handset (1) or the base unit (2). That is, since it can be freely transferred to either of the handset (1) and the base unit (2),
For example, when a call is received from an outside line, it is received by the base unit (2), and then the call is transferred to the handset (1), but a call with the base unit (2) becomes necessary. This can be realized, or a call can be made between three parties.

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

Effect of the Invention In a cordless telephone, during a call with an external line telephone, whether the call is from the handset (1) or the base unit (2), the call is made to the external line telephone, the handset (1) and the base unit ( It can be performed among the three parties of 2). In addition, the call between the three parties can be made simple and reliable by operating only one intercom key.

[Brief description of drawings]

1, 4 and 5 are diagrams for explaining the present invention, and FIGS. 2 and 3 are system diagrams of one 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, and the handset and the base unit are respectively provided. One intercom key is provided, and a connection control circuit is provided to the base unit to supply information that each intercom key is operated to control connection with a telephone line. One of the handset and the base unit is an outside line. When the connection control circuit determines the information indicating that the intercom key has been operated on the one side during a call with the telephone, the outside line is held by the control of the connection control circuit of the base unit, and the handset and the Up to the other of the base units A control signal is transmitted from one side to call the other side, and after this calling, a call as an intercom is enabled between the one side and the other side. Alternatively, when the connection control circuit determines that one of the other ones of the intercom keys has been operated, the connection control circuit of the base unit controls the connection control circuit to release the holding of the outside line so that the base unit is connected to the outside line. A cordless telephone which is connected to the outside line telephone, the base unit, and the handset so that the telephone call can be made among three parties.