JP2643395B2 - Cordless telephone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The description will be made in the following order.

A Field of Industrial Use B Outline of the Invention C Prior Art D Problems to be Solved by the Invention E Means for Solving the Problems (FIG. 1) F Function G Example (FIGS. 1 and 2) H A. Field of the Invention The present invention relates to a cordless telephone.

B. Summary of the Invention The present invention provides a multi-cordless telephone that performs call processing on a plurality of slaves in a predetermined sequence so that a slave already in a call can also respond to the incoming call. is there.

C Prior Art A low power type cordless telephone is based on the MCA system, and has 87 communication channels and 2 control channels.

Therefore, as an extension of the functions or capabilities of such a cordless telephone, a so-called multi-cordless telephone in which a plurality of telephone lines and a plurality of slaves can be used in combination for one base unit is considered. ing.

First, an example of such a multi-cordless telephone will be described with reference to FIG.

In the example shown in the figure, there are two external lines and up to eight slave units, and only one control channel is used.

In the figure, (1A) to (1H) denote first to eighth handsets (slaves). These handsets (1A)
Since (1H) has the same configuration, and will be described as a representative with the handset (1A), (110) is a transmitting circuit, and (120) is a receiving circuit. Then, the transmission circuit (11
0) converts the voice signal St and the command signal CMND (to be described in detail later) into an upstream channel FM signal Su and transmits the signal. The receiving circuit (120) receives the downstream channel FM signal Sd and It demodulates the audio signal Sr and the command signal CMND.

In addition, (131) is a dial key, (132) is a talk key, and the talk key (132) is a non-lock type push switch. Each time the key (132) is pressed, the handset (1A) is set to the standby mode. And the talk mode is alternately switched. And the handset (1
In A), in the standby mode, the reception mode and the sleep mode are alternately repeated on the downlink control channel (details will be described later). In the talk mode, continuous reception and transmission are performed.

Further, (133) to (137) are auxiliary keys such as extension keys constituted by non-lock type push switches, (139) is a ringer speaker, and (140) is a microcomputer for system control. In the microcomputer (140), the command signal CMND transmitted by the transmission circuit (110) is formed, and the command signal CMN extracted from the reception circuit (120) is formed.
D is determined. Further, in the microcomputer (140), control signals TCTL and RCTL for controlling transmission / reception permission / inhibition of the transmission circuit (110) and a channel on which the transmission circuit (110) and the reception circuit (120) perform transmission / reception are also formed.

A RAM (141) stores a 25-bit system identification code SYID for distinguishing the multi-cordless telephone from other cordless telephones. Furthermore, handset (1A)-(1H)
Are assigned handset numbers of "1" to "8" in order to distinguish these handsets (1A) to (1H) from each other (the order of assignment is arbitrary). The identification code HSID is stored in the RAM (141). When the identification code (handset number) HSID is “0”,
All handsets (1A) to (1H) correspond.

(2) is the base station (master), (3)
A) and (3B) indicate telephone lines (external lines). In the base station (2), (21A) to (21C) indicate base units, and these base units (21A) to (21A)
(21C) is a transmission circuit (21) similar to the transmission circuit (110) and the reception circuit (120) in the handsets (1A) to (1H).
0) and a receiving circuit (220). However, the receiving circuits (220) to (2) of these base units (21A) to (21C)
20) is in the receiving mode continuously on the uplink control channel during non-communication.

Furthermore, in the base station (2), (22)
Is a call switch circuit, (23A) and (23B) are external line interface circuits, and (24) is a microcomputer for master control. In this case, the switch circuit (22)
Is based on the base unit (21A)
(21C) and between the base units (21A) to (21C) and the interface circuits (23A) and (23B). In addition, the interface circuit (23A),
(23B) is a 4-wire / 2-wire conversion circuit (231), a switch circuit corresponding to a hook switch of a general telephone (232), a dial tone signal (DTMF signal) forming circuit (233), and detection of a ring tone signal A circuit (234).

In addition, the microcomputer (24) has a handset (1A)
In addition to performing the same processing as the microcomputer (140) in (1H), the handset (1A) to (1H), the communication channel, the base unit (21A) to (21C), the line (3A),
It manages the overall operation of this cordless telephone such as the usage status of (3B). And (241) is ROM
In this ROM (241), a system identification code SYID is written.

FIG. 3 shows an example of a signal format of the command signal CMND. The signal CMND has a 24-bit bit synchronizing signal BSYN at the beginning, followed by a 16-bit frame synchronizing signal.
Has FSYN. In this case, these signals BSYN and FSYN are, for example, BSYN = “101010 ‥‥‥‥‥‥ 10” FSYN = “1100010011010110” ‥‥ for the up channel FSYN = “1001001100110110” ‥‥ for the specific bit indicated for the down channel Has a pattern.

Further, the command signal CMND has a 25-bit system identification code SYID, a 12-bit error correction code ECC for the code SYID, and a 3-bit dummy bit DBIT in order following the signal FSYN. DB
Following the IT, there is a 5-byte control code CTRL.

In this case, the control code CTRL is the first byte CTL1
Is a code indicating the control contents of the handsets (1A) to (1H) and the base station (2).
L2 to the fifth byte CTL5 are parameters or data related to the first byte CTL1. For example, when the base station (2) notifies any of the handsets (1A) to (1H) of the channel number of the communication channel, CTL1: a code indicating the notification of the communication channel CTL2: partner Handset identification code HSID of handset CTL3: Channel number of call channel CTL4, CTL5: Dummy. In most cases, the second byte CTL2 is
The handset identification code HSID as described above.

When the handsets (1A) to (1H) or the base units (21A) to (21C) endure the command signal CMND, the microcomputer (140) or (24) uses the identification code SYID included in the signal CMND. (And HS
ID) is checked to see if it matches the identification code SYID (and HSID) stored in its own RAM (141) or ROM (241).
CMND is valid, and if they do not match, it is invalid.

FIG. 4 shows the operation when the handsets (1A) to (1H) are in the standby mode.

That is, since the handsets (1A) to (1H) operate using a battery (generally, a rechargeable battery) as a power source, it is necessary to reduce the current consumption as much as possible. Therefore, in the actual handsets (1A) to (1H), as shown by the solid line in FIG. A, for example, the reception mode is set for 0.2 seconds every 2 seconds, and only the reception operation is performed on the downstream control channel, and the remaining operation is performed. In the sleep mode (power down mode) for 1.8 seconds, all the power supplies except for a small part of the microcomputer (140) are turned off. Note that the handsets (1A) to (1H) are not synchronized among the handsets (1A) to (1H) for 0.2 seconds during which the handsets (1A) to (1H) are in the reception mode.

Then, assuming that it necessary at any time t ₁ the base station (2) is to call the example handset (1A), the base station (2), as shown in FIG. B, a command signal for calling the handset (1A) CMND
Is transmitted many times over, for example, 2.5 seconds. Note that the length of one time of the signal CMND is, for example, 120 msec, and is transmitted through a downlink control channel.

And base station (2) is 2.5
If repeatedly send command signal CMND for seconds, during which 2.5 seconds, since the handset (1A) is always once has the reception mode, will receive the command signal CMND for example at time t ₂ .

Therefore, in the handset (1A), upon receiving the command signal CMND at time t _2, as shown by a broken line in FIG. A, thereafter continuously becomes receiving mode, the command signal CMND from the base station (2) When but ending time t _3, as shown in FIG. C, and the time t ₃ with respect to the time t ₄ after a predetermined period of time tau, the command signal CMND which responds to the command signal CMND, the uplink control channel To the base unit (2).

Therefore, when the handsets (1A) to (1H) are in the standby mode, the handsets intermittently perform the receiving operation, and in most of the remaining periods, are in the sleep mode, so that the current consumption is small.

[Call from handset]

A call from the handsets (1A) to (1H) to an outside line is performed, for example, as in a connection sequence shown in FIG. That is, in the figure, the solid line in the vertical direction indicates the channel used by the handset and the base unit.
Is a control channel, and V is a communication channel. Also,
The solid line indicating this channel is in the sleep mode when it is a single line (this is only for handset), it is in the reception mode when it is a double line, and it is in the talk mode during the hatched period, and transmission is permitted. Is shown. Although the vertical direction is the time axis direction, this time axis is not linear for the sake of drawing.

Then, for example, when the handset (1A) is in the standby mode and the talk key (132) is pressed, this is detected by the microcomputer (140), and the transmission control signal TCTL is supplied from the microcomputer (140) to the transmission circuit (110). As a result, the transmission circuit (110) and the reception circuit (120) are permitted to transmit and receive on the control channel to enter the talk mode, and the microcomputer (140) sets the control code CTRL to a call request and its handset. A command signal CMND indicating the identification code HSID is formed.
The ND is supplied to the transmission circuit (110).

Therefore, in the transmission circuit (110), the signal CMND is converted into an FM signal (FSK signal) Su of the uplink control channel, and this signal Su is transmitted to the base station (2) via the antenna (100).

Then, in the base station (2), the signal (radio wave) Su is received by the antenna (200), and the received signal Su is transmitted to the base units (21A) to (21C).
Supplied to In this case, for example, if the base unit (21A) is vacant,
Since the receiving circuit (220) of A) is in the receiving mode of the uplink control channel, the command signal CMND is demodulated from the FM signal Su in the receiving circuit (220), and this signal CMND is supplied to the microcomputer (24). It is checked whether the identification code SYID included in the signal CMND matches the identification code SYID of the ROM (241).

Then, in this case, the transmission control signal TCTL is supplied from the microcomputer (24) to the transmission circuit (210) because the transmission and the request are the same from the handset (1A). And the control signal CTRL is formed in the microcomputer (24) by the control code CTRL, and a command signal CMND indicating the handset identification code HSID and the channel number of the communication channel is formed in the microcomputer (24). ).

Therefore, the transmission circuit (21) of the base unit (21A)
At 0), the signal CMND is converted into an FM signal Sd of a downlink control channel, and this signal Sd is transmitted to the handsets (1A) to (1H) through the antenna (200).

Then, in the handset (1A), when the FM signal Sd is transmitted from the base station (2) through the downlink control channel, the FM signal Sd is received by the antenna (100) and supplied to the receiving circuit (120). (1
From 20), the command signal CMND is taken out and supplied to the microcomputer (140).

Then, the identification code included in the command signal CMND
SYIS, HSID is the identification code S stored in the RAM (141)
Since they match YIS and HSID, the transmission circuit (110) and the reception circuit (120) are switched to the communication channel of the channel number indicated by the control signal CTRL in the received command signal CMND by the control signals TCTL and RCTL.

In the base unit (21A), when the communication channel is instructed to the handset (1A) by the command signal CMND, the microcomputer (24) subsequently sends the transmission circuit (21A).
0) and the transmission control signal TCTL and the reception control signal RCTL are supplied to the reception circuit (220), and the transmission circuit (210) and the reception circuit (220) transmit the channel number designated by the microcomputer (24) to the handset (1A). Switch to the call channel.

Therefore, a communication channel has been opened between the handset (1A) and the base unit (21A).

At this time, the remaining handsets (1B) to (1H) also receive the FM signal Sd transmitted from the base station (2), but the transmitted handset identification code HSID is different from the own handset. Since they do not match, the standby mode in the downstream control channel is maintained.

Then, in the handset (1A), the control code
CTRL indicates a command signal CMND indicating that the switching to the communication channel is completed, and this signal CMND is transmitted to the base station (2) by the FM signal Su of the switched communication channel.

And this FM signal Su is the base station (21A)
And the command signal CMND received by the microcomputer (2
4), the microcomputer (24) forms a command signal CMND indicating a response to the control code CTRL, and this signal CMND is transmitted to the handset (FM) by the FM signal Sd of the communication channel switched from the base unit (21A). 1A)
Sent to

Further, in the base station (2), a vacant interface circuit is selected from the interface circuits (23A) and (23B). In the case of the figure, the interface circuit (23A) is selected and its switch circuit (232) is selected. Off-hook state and switch circuit (22)
Is controlled by the transmission circuit (210) of the base unit (21A)
And the receiving circuit (220) is connected to the conversion circuit (231) of the interface circuit (23A) through the switch circuit (22).

Therefore, the base unit (21A) is connected to the line (3A) through the switch circuit (22) and the interface circuit (23A). As a result, the handset (1A) is connected to the circuits (21A), (22) , (23A) to the line (3A).

[Dial and call]

Subsequently, when the caller inputs the telephone number of the other party using the dial key (131) of the handset (1A), the control code CTRL indicates the transmission of the telephone number and a command signal CMND indicating the telephone number is formed. , This signal CMND,
The signal is converted into the FM signal Su of the communication channel and transmitted.

Therefore, in the base station (2),
The command signal CMND is obtained from the receiving circuit (220) of the base unit (21A). Since the control code CTRL of the signal CMND indicates the transmission of the telephone number and indicates the telephone number, the forming circuit ( 233) Microcomputer (24)
Is controlled according to the telephone number to form a dial tone signal corresponding to the telephone number sent from the handset (1A), and this signal is converted by the conversion circuit (231).
Through the switch circuit (232) to the telephone line (3A).

Then, when the other party answers the telephone, an audio signal Sr from the other party is transmitted to the base unit (21A) through the signal line of the line (3A) → the switch circuit (232) → the conversion circuit (231) → the switch circuit (22). It is supplied to a transmission circuit (210).
Therefore, the signal Sr is the FM signal of the downlink communication channel.
The signal is converted to Sd, and this signal Sd is transmitted from the antenna (200).

Then, the signal Sd is received by the handset (1A), an audio signal Sr is extracted from the receiving circuit (120), and the signal Sr is supplied to the receiver (121).

At the time of transmission, the audio signal St from the transmitter (111) is transmitted.
Is supplied to the transmitting circuit (110) and is converted into an FM signal Su of the uplink communication channel, and this signal Su is transmitted to the antenna (100).
To the base station (2).

Then, in the base station (2), the signal Su is received by the base unit (21A), and a signal St is extracted from the receiving circuit (220). This signal St is converted into a switch circuit (22) → an interface circuit (23A). Is supplied to the line (3A) through the signal line of the conversion circuit (231) → switch circuit (232) and sent out to the other party's telephone.

[End talk]

When the call is terminated, for example, as shown in FIG. 6, when the talk key (132) of the handset (1A) is pressed, the control code CTRL changes to a command signal CMND indicating the end of the call and the handset identification code HSID. This signal is formed
CMND is transmitted to the base station (2) by the FM signal Su of the communication channel.

Then, the command signal CMND is extracted from the receiving circuit (220) of the base unit (21), and the microcomputer (24) determines that the call has ended. As a result, the transmission of the transmission circuit (210) of the base unit (21A) is controlled by the control signal TC.
In addition to being inhibited by the TL, the receiving circuit (220) is set to the receiving mode of the uplink control channel by the control signal RCTL. Further, the switch circuit (232) of the interface circuit (23A) is also turned on-hook.

Further, also in the handset (1A), after transmitting the command signal CMND indicating the end of the call, the transmission circuit (110) prohibits the transmission by the control signal TCTL, and the reception circuit (12)
0) is set to the standby mode on the downstream control channel by the control signal RCTL.

[Incoming call to handset]

An incoming call from an outside line to the handsets (1A) to (1H) is performed, for example, according to a connection sequence shown in FIG.

That is, for example, when a call is received via the line (3A), the ring tone signal is detected by the detection circuit (234) of the interface circuit (23A), and this detection signal is supplied to the microcomputer (24). Then, a free base unit among the base units (21A) to (21C) S, for example, the base unit (21A) is selected, and one of the free handsets among the handsets (1A) to (1H) is selected. For example, the handset (1A) is selected as a representative (hereinafter, as necessary, the handset selected as the representative is referred to as a “representative handset”, and the other handsets are referred to as “general handsets”).

Then, next, the control code CTRL is an incoming call,
The identification code HSID of the representative handset (1A), the channel number of the call channel, and a command signal CMND indicating that the call is a simultaneous call are formed, and this signal CMND is transmitted by the base unit (21A) through the downstream control channel. . Incidentally, the transmission of the signal CMND is repeatedly carried out for 2.5 seconds (Fig. 4 period t ₁ ~t ₃₎ of.

When the end of transmission of the signal CMND (time t _3), the base unit (21A), a command signal uplink control channel indicates an incoming call response from the monitored representatively handset (1A) for a predetermined period of time T ₁ The presence or absence of CMND is checked.

In the representative handset (1A), at a time point t _2, the reception mode rises from the sleep mode, at a time point t _3, the identification code SYI which sent
D and HSID are checked, and in this case, since these match their own, transmission of the FM signal Su is permitted, and the control code CTRL is an incoming call response and the handset identification code HSID is the command signal CMND is formed indicating a, this signal CMND is transmitted to the base station (2) at time t ₄ in the period T ₁ in through the uplink control channel.

Therefore, in the base station (2),
Since the period T ₁ is the command signal CMND of the call response will be successfully received, the channel of the base unit (21A) is switched to the call channel indicated in the handset (1A).

In the representative handset (1A), when a command signal CMND indicating an incoming call response is transmitted, the channel is subsequently switched to the communication channel instructed by the base unit (21A), and thereafter, the control code CTRL changes the channel. Is completed, and this signal CMND is transmitted through the switched speech channel.

Further, even in a general handset (1B) ~ (1H), upon receiving the command signal CMND indicating an incoming call from a period (t ₁ ~t ₃₎ to the base unit (21A), the identification code HS
Although ID do not match, together with the identification code SYID match, it indicates simultaneous incoming calls made from the standby mode and the reception mode, followed by a time t ₃ to the reference indicated by the same timing as the representative handset (1A) and The receiving mode is set for the communication channel that has been set.

Then, in the base unit (21A), when the channel is switched to speech channel, the control code CTRL from monitored representatively handset (1A) thereof switched call channel for a predetermined period of time T ₂ following the period T ₁ It is checked whether a command signal CMND indicating completion of channel switching has been transmitted.

Then, a command signal CMND for channel switching completion
But when not transmitted within the period T ₂ are, the base unit (21A) is reset to the original standby state, the case, the command signal CMND of the channel switching completion, transmitted within the period T ₂ Control code
Command signal CMND indicating that CTRL rings the ringer
Is formed, and this signal CMND is transmitted through the communication channel.

For handsets (1A) to (1H),
T ₁ to be followed by the speech channel for a predetermined period of time T is monitored is checked received command signal CMND of the ringer, when the command signal CMND of the ringer is received within the period T _3, the oscillation by the microcomputer (140) Circuit (1
38) is controlled to form a ringer signal, and this signal is supplied to the speaker (139), and the speaker (139) simultaneously emits a bell sound indicating an incoming call.

Then, the handsets (1A) to (1H) are polled. That is, a command signal CMND indicating that the control code CTRL is a request for a called response and the identification code HSID of the handset (in this case, the code HSID of the handset (1A)) is formed. Sent through the channel.

When the command signal of the called response request is received by the handset (1A), the handset (1A)
, The control code CTRL is a response to the called, the identification code HSID and whether any of the keys (132) to (137) are pressed, and if so, which key Is transmitted through the communication channel.

Then, in the base station (2), the control code CTRL of the transmitted command signal CMND is checked, and when the control code CTRL does not indicate that the talk key (132) has been pressed, and when the command signal CMND
When the base unit (21A) fails to receive itself, the same command signal CMND is exchanged with the next handset, in this case, the handset (1B), so that the handset (1A) to ( 1H), the command signal CMND requesting the called response is transmitted in order through the communication channel, and each time the command signal CMND is transmitted, the command signal CMND of the called response from the handset is checked. You.

Thus, the handsets (1A) to (1H) are polled in order, and wait for a response from the handsets (1A) to (1H). In addition, handset (1A)-(1
H), the transmission is permitted only when the command signal CMND of the called response is transmitted.

Then, during this polling, for example, the handset (1
In C), when the talk key (132) is pressed, when the handset (1C) is polled next time, the control code CTRL of the command signal CMND of the called response indicates that the called response is the calling response, and the identification code HSID , A call response command signal CMN indicating that one of the keys (132) to (137) has been pressed and that the pressed key is the talk key (132).
D is formed, together with the signal CMND is transmitted, the oscillation circuit of the handset (1C) (138) is ringer is turned off is turned off (time t _6).

And the command signal from this handset (1C)
When the CMND is received at the base station (2), the control code CTRL indicates that the handset is specified and that the handset (in this case, the handset (1
A command signal CMND indicating the identification code HSID of C)) is formed, and this signal CMND is transmitted.

And this signal CMND is handset (1A)-(1H)
In the handset (1C) that has pressed the talk key (132), the call is permitted thereafter, and the remaining handsets (1A), (1B), (1D)-
In (1H), the oscillation circuit (138) is turned off and the ringer is turned off, and then the control channel enters the standby mode of the standby mode.

Subsequently, the microcomputer (24) controls the switch circuit (22) to transmit the transmission circuit (210) of the base unit (21A) 4.
And the receiving circuit (200) is connected to the conversion circuit (231) of the interface circuit (23A) through the switch circuit (22), and the switch circuit (232) is set to an off-hook state. Therefore, the base unit (21A) It is connected to the line (3A) through the switch circuit (22) and the interface circuit (23A).

Therefore, a communication channel is opened between the handset (1C) and the base unit (21A), so that a call can be made between the other party and the handset (1C).

On the other hand, the battery of the representative handset (1A) is low, the representative handset (1A) is out of the communication area, or another cordless telephone is near the handset (1A). reasons such as due to the use of, when the period T ₁ can not receive the command signal CMND of the call response from the representative handset (1A), the connection sequence is thereafter becomes the Figure 8.

That is, within the period T _1, the no call response from the representative handset (1A), the time waiting period T ₃ in the base station (2) is performed. The period T _3, for example, as shown in FIG. 7, the representative handset (1A) has responded normally, the time when the ringer command signal CMND is transmitted to the handset (1A) ~ (IH) when the time t _5, is a period _{(t 3 ~t 5) = T} 1 + T 3 become such length. That is, when viewed from the handset (1A) ~ (1H), from the time t ₃ to time t ₅ after the elapse of the period (T ₁ + T _3), so that the ringer command signal CMND is transmitted.

Then, at time point t _5, handset the next free, for example, a handset (1B) is selected as the representative handset, the above-described processing is performed on the handset (1B).

For handsets (1A) to (1H),
to t _5, it is reset from the reception mode in the speech channel in the sleep mode in the standby mode in the control channel.

Therefore, at the time of an incoming call, one of all available handsets is selected as the representative handset, and
The incoming call is notified to all available handsets, and the representative handset is sequentially switched until an incoming call response is obtained from the representative handset. If there is an incoming call response from the representative handset, polling is performed on all available handsets to check the response of the handset, and if there is a response, processing for a call is performed for the handset. I will continue.

Thus, when there is an incoming call from an outside line, the ringer rings in all the valid handsets, and when the talk key (132) is pressed, the handset that is first polled after pressing the talk key (132) receives the ringing. You can talk to them.

[Extension call]

This is a call between any two of the handsets (1A) to (1H), and is performed as follows.

That is, for example, when the handset (1A) is in the standby mode, the extension key (133) of the auxiliary keys (133) to (137) is pressed, and then, of the dial keys (131), the handset of the handset to which an extension call is desired is made. Pressing the numeric key corresponding to the handset number (which is equivalent to the handset identification code HSID) causes the control code CTRL to
3) that any one of (137) to (137) is pressed, that the pressed key is the extension key (133), and that the dial key (13
1) Pressed numeric key (other party's handset identification code HDIS) and own handset identification code HSID
Is formed, and the command signal CMND
CMND is transmitted to the base station (2) by the FM signal Su of the uplink control channel.

If the base unit (21A) is empty, for example, the receiving circuit (22
0), the command signal CMND is taken out, it is determined that the request is for an extension call from the handset (1A), and thereafter, the handset (1A) and the base unit (21A) are connected in the same manner as when making a call. The call channel is opened.

Further, in the base station (2), a vacant base unit and a vacant communication channel are selected by the microcomputer (24). For example, if the base unit (21B) is vacant, the base unit (2B) is selected.
1B) command signal through the downstream control channel
The CMND FM signal Sd is transmitted. However, at this time, the control code CTRL in the command signal CMND indicates that the call is an extension call, the handset (1A) has a handset identification code HSID of the other party desiring the extension call, and data indicating the channel number of the call channel. Is done.

Then, when the FM signal Sd of the command signal CMND is received by the handset (1A) of the other party desired by the handset (1A), for example, a bell sound is output from the speaker (139) of the handset (1H). Is sounded,
When the other party presses the talk key (131) of the handset (1H), a communication channel is opened between the handset (1H) and the base unit (21B).

In the base station (2), since the extension call is performed, the switch circuit (22) is controlled by the microcomputer (24), and the transmission circuit (210) and the reception circuit (220) of the base unit (21A) are switched by the switch circuit ( Through 22), it is connected to the receiving circuit (220) and the transmitting circuit (210) of the base unit (21B).

Therefore, the handset (1A) is connected to the handset (1H) through the base station (2), and thereafter, an extension call can be made between the handsets (1A) and (1H).

Then, the call ends and the handset (1A), (1H)
On the other hand, for example, the handset (1A)
When 1) is pressed, the handset (1A) and the base unit (21A) end the call in the same manner as the end of a call during a call with an outside line, and these units enter a standby mode. In addition, handset (1H) from base unit (21B)
A command signal CMND indicating that the control code CTRL is the end of the call and the identification code HSID of the handset (1H) is sent to the handset (1H) and the base unit (21B). Mode.

[Other operations]

A similar protocol may be used to transfer an outside line from one handset to another, to make a three-party call between an outside line and two handsets, or to call the remaining handsets from one handset simultaneously. Done.

D Problems to be Solved by the Invention By the way, if the handset, the base station, and the telephone line are one-to-one cordless telephones, an intercom call (a call between the handset and the base station is made like an interphone). ), When there is an incoming call from an outside line, the intercom call is temporarily terminated, and then, for example, by pressing a talk key, the outside line is captured and the call to the outside line is started. be able to.

However, in the above-described multi-cordless telephone, for example, when the handset (1A) is performing an extension call with the handset (1B) through the base station (2), or when the handset (1A) is connected to the base station (1A). When an external call is made through a two-band line (3A), an incoming call is received through the line (3B), and the call is terminated once, as in a one-to-one one-less cordless telephone. Then, when the talk key (132) is pressed, the talk channel between the handset (1A) and the base station (2) is released at the time of the end of the call.
It takes some time before the call channel is opened again between the handset (1A) and the base station (2) by pressing.

Also, when the call channel is opened, the base station (2) cannot distinguish it from a general call,
The vacant telephone line (3A) is connected (off-hook) and cannot respond to incoming calls on the line (3B).

The present invention is to solve the above problems.

E Means for Solving the Problems Therefore, in the present invention, when a call is received from an outside line,
The base station informs all available handsets via the control channel that there is an incoming call, and when there is a busy handset, the base station communicates with the busy handset through the call channel used for the call. Notify that a call has been received.

In addition, in a handset during a call, when a predetermined key is pressed when an incoming call is notified, a call termination or hold process is performed with respect to the other party of the call, and a call is made to the outside line on which the call is received. Open a call channel through the base station during.

F action The handset during a call is connected to an outside line.

G Embodiment FIG. 1 shows a connection sequence in the case where there is a handset during a call at the time of receiving a call. A routine (600) on the right side of the figure is a routine executed by the microcomputer (24) when receiving a call, and is written in a ROM (not shown) of the microcomputer (24).

First, there is no handset during a call when there is an incoming call. In this case, the following processing is performed.

That is, when there is an incoming call through, for example, the line any time t ₀ (3A), the ring tone signal is detected by the detection circuit of the interface circuit (23A) (234), supply the detection signal to the microcomputer (24) Is done.

Then, the routine (600) is executed by the microcomputer (24), and in step (601), the call incoming flag U
FLG is reset to "0", and then in step (602), it is checked whether there is a talking handset. In this case, since there is no talking handset, the process proceeds from step (602) to step (602). Proceed to (610).

Then, in the step (610), the processing from the transmission of the command signal CMND indicative of the incoming call in the time period t ₁ ~t ₅ as described with reference to Figure 7 to the transmission of the command signal CMND indicating that sound the ringer row We, then in step (620), the polling during the period t ₅ ~t ₆ are performed.

Then, for example, when the tone key (132) is pressed in the handset (1A) and this is determined in step (620), the process proceeds to step (631).

Then, in step (631), the flag UFLG is checked, and in this case, since UFLG = "0", the process proceeds from step (631) to step (632), and in this step (632), the control code A command signal CMND indicating that CTRL is a designation of the handset and an identification code HSID of the handset (in this case, the handset (1A)) is formed, and this signal CMND is transmitted from the base unit (21A) through the communication channel to the handset ( 1
A) to (1H).

Then, when the signal CMND is received by the handset (1A), the handset (1A) specifies itself, so that the handset (1A)
A) Base unit (21A) through the call channel
It will be connected to.

In the remaining handsets (1B) to (1H),
Since the user is not designated, the ringer is stopped and then the control channel enters the sleep mode of the standby mode.

Further, in the base station (2), the processing of the microcomputer (24) is performed from step (632) to step (6).
33) In this step (633), the microcomputer (24) controls the switch circuit (22) to control the transmission circuit (210) and the reception circuit (200) of the base unit (21A).
Is connected to the conversion circuit (231) of the interface circuit (23A) through the switch circuit (22), and the switch circuit (232) is turned off-hook in step (634).

Therefore, the base unit (21A) is connected to the circuit (3A) through the switch circuit (22) and the interface circuit (23A).

Therefore, the handset (1A) is connected to the circuit (21A),
Since the connection to the line (3A) is made through (22) and (23A), it is possible to make a call with the other party who made the call thereafter.

Also, the processing for the incoming call of the microcomputer (24) ends here, and the process proceeds to the next processing (650).

On the other hand, if there is a busy handset at the time of receiving a call, the following processing is performed. In the following description, the handset (1A), base unit (21
A) Assume that the interface circuit (23A) and the line (3A) are in use for a call. The communication channel used at this time is the Va channel.

That is, the time t ₀ is in the handset (1A) is a call, this time, when there is an incoming call, the processing of the microcomputer (24), the process proceeds from step (602) to the step (603), the step ( At 603), a control signal CTRL is formed, and a command signal CMND indicating that the ringer is to be sounded and that the partner to be ringer is the handset (1A) is formed,
This signal CMND is used for the base unit (21A)
And to the handset (1A) via the communication channel Va. Therefore, in the handset (1A), while a call is in progress, the oscillation circuit (138) is turned on, and a ringer for notifying an incoming call is sounded.

Subsequently, the process of the microcomputer (24) proceeds from step (603) to step (604). In this step (604), the flag UFLG is set to "1", and thereafter, steps (610) and (620) are performed. It is executed in order. However, in this case, since the base unit (21A) and the communication channel Va are in use, the call processing in step (610) and the step (620) are performed using, for example, the base unit (21B) and the communication channel Vb (Vb 例 え ば Va). ) Polling is performed.

Also, during the polling in step (620), is it possible to obtain a command signal CMND indicating that the external key (133) of the handset (1A) is pressed from the receiving circuit (220) of the base unit (21A) during a call. It is also checked.

That is, in the polling of step (620), a command signal CMND indicating that the talk key (132) has been pressed is transmitted from any of the handsets (1B) to (1H) that are not in a call. Until,
Alternatively, the polling and the reception of the external line key are continued until the command signal CMND indicating that the external line key (133) is pressed is transmitted from the handset (1A) during the call.

Then, during this polling, when the outside line key (133) is pressed in the handset (1A) during a call, the oscillation circuit (138) is turned off, the ringer is turned off, and the control code is turned off. CTRL is the outside key (133)
Is formed, and this signal CMND is transmitted from the handset (1A) to the call channel.
It is sent to the base unit (21A) through Va.

Then, this signal CMND is detected in step (620), and the processing is performed from step (620) to step (631).
In this case, since UFLG = "1", the process further proceeds to step (641). And this step (64
In step 1), the reason why the polling in step (620) is terminated is that the external key (13) of the talking handset (1A) is used.
3) It is checked whether it was because it was pressed,
In this case, so, the process proceeds from step (641) to step (642).

Then, in step (642), step (632)
Similarly to the above, a command signal CMND indicating that the control code CTRL is the designation of the handset and the identification code HSID of the handset (in this case, the handset (1A)) is formed, and this signal CMND is transmitted to the base unit (21B). Handset (1B) through (1H) through call channel Vb
Sent to

Then, in the handsets (1B) to (1H), since the control code CTRL of the signal CMND does not specify itself,
After the ringer is stopped, the control channel enters a sleep mode of a standby mode.

Further, in the base station (2), the processing of the microcomputer (24) is performed from step (642) to step (64).
Proceeding to 3), in this step (643), the transmission of the base unit (23B) is prohibited and the reception mode on the control channel is set. Next, in step (644), the switch circuit (2A) of the interface circuit (23A) is turned on.
32) goes on-hook and therefore the line (3A)
With the other party is placed in a closed state.

Subsequently, in step (645), the base unit (21A) is connected to the interface circuit (23B) through the switch circuit (22), and in step (646), the switch circuit (232) of the interface circuit (23B) is connected. It goes off-hook.

Therefore, the base unit (23A)
2), with would be connected to a circuit (3B) through (23B), the handset (1A) is because it is connected to the base unit (23A) via the speech channel Va from time t ₀ before the handset (1A ) Can talk to a new party on the line (3B).

During the polling in step (620), when the talk key (132) of another handset is pressed before the external line key (133) is pressed in the handset (1A) that was in the call until then, Processing is a step (62
From step (0), the process proceeds to step (641) through step (631). In step (641), the reason for terminating the polling in step (620) is that the handset (1
The process proceeds from step (641) to step (632) because it is not because the outside line key (133) of A) is pressed, and thereafter, the same process as the incoming call when there is no handset during a call is performed.

Thus, according to the present invention, when a certain handset receives a call during a call, the other handset is notified of the call, and the other handset is also notified of the call. When the handset performs a predetermined key operation, the handset is connected to the external line on which the call was received through the previous communication channel. And a reliable connection to the called external line.

In the above description, a call is received from an outside line during a call to an outside line. However, the same processing may be performed when a call is received from an outside line during an extension call. Also, when the handset during a call presses the hold key among the keys (134) to (137) and then presses the outside line key (133),
The switch circuit (232) puts the outside line on which the call was made until then on hold, performs the same processing as above for the newly received outside line, and after the call is terminated, if the hold key is pressed again, the original Can be released and the handset can be connected again.

Further, at the time of incoming call (time t ₀ ) and at the time of polling at step (620), the base station (2) knows the currently used handset, and selects a representative handset except for this currently used handset. And can also poll.

H Effect of the Invention According to the present invention, when a certain handset receives a call during a call, the other handset is notified of the call, and the handset during the call is also notified of the call. When the middle handset performs a predetermined key operation, the handset is connected to the outside line that has received the call through the previous communication channel, so that the connection with the outside line that has received the call is quickly established. In addition to this, it is possible to reliably connect to the external line from which the call was received.

[Brief description of the drawings]

1 and 2 are a sequence diagram and a system diagram showing an example of the present invention, and FIGS. 3 to 8 are diagrams for explaining the same. (1A) to (1H) are handsets, (2) is a base station, (110) and (210) are transmission circuits, (120) and (22)
0) is a receiving circuit.

Claims (1)

(57) [Claims] When a communication channel is opened between a plurality of slave units and a master unit, a communication channel is opened from the master unit to the slave unit through a control channel. In a cordless telephone of the MCA system in which data for designating the communication channel is transmitted and the communication channel is opened between the child device and the parent device based on the transmitted data, one child device When there is an incoming call from an outside line during a call, the parent device notifies the remaining child device through the control channel of the incoming call, and the child device is using the child device during the call. Informing the incoming call through a call channel, and when a predetermined key is operated in the slave unit during the call, the slave unit is connected to the communication channel used by the slave unit until then, and Cordless telephone which is adapted to connect to the outside line for which the above incoming call through the machine.