JP2001127876A - Extension telephone set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extension telephone set for avoiding collision of automatic recording functions between a master unit and a slave unit. SOLUTION: A slave unit 100 which composes a digital cordless telephone together with the master unit having the automatic recording function for receiving state information periodically transmitted from the master unit is provided with a control part 170 for controlling the automatic recording function by a recording/reproducing part 160 and the control part 170 has a master unit state detecting part 172 for detecting whether the automatic recording function is turned on or off referring to the state information, an automatic recording ON/OFF information storage part 173 for storing ON/OFF information showing whether the automatic recording function of the present set is turned on by a user at present, a priority information storage part 174 for storing priority information showing which one of automatic recording functions of the master unit and the slave set is to be given priority, and an automatic recording cancel part 175 for turning off the automatic recording function of the slave set or turning off the automatic recording function of the master unit by using a remote function when the automatic recording functions of both the master unit and the slave set are turned on.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parent-child telephone device such as a digital cordless telephone device in which each of a parent device and a child device has an answering machine function.

[0002]

2. Description of the Related Art Conventionally, a cordless telephone device includes a master unit connected to a telephone line and a slave unit that communicates wirelessly with the master unit and can communicate with an external telephone device via the master unit. Consists of Some cordless telephone devices have a voice mail function. In recent years, digital cordless telephone devices have been sold in which the slave unit can also be used as a portable unit of a personal handyphone system (PHS), and the slave unit alone can communicate via a public base station. Such a self-operating mode that communicates with the base unit,
Some handset units that can be switched to the public mode for communication with the public base station are those that have an answering machine function that contributes to the improvement of convenience in the use of the public mode and can also be used in the private mode. is there.

[0003] A user of a digital cordless telephone device in which both the master unit and the slave unit have an answering machine function sets whether the answer phone function is turned on or off for each of the master unit and the slave unit. can do. Here, the answering machine function refers to a function of recording a voice or the like sent from the outside when a call is received from the outside and receiving a call, on a recording medium such as a tape or a recording / playback IC. Turning on the answering machine function refers to a standby state in which an incoming call is received and a voice or the like is recorded when a call from outside is received.

[0004] When the number of calls from an external telephone device, that is, the number of ringers exceeds a preset number, a master unit or a slave unit with the answering machine function turned on automatically receives a call and receives an external call. Receives and records audio sent from the telephone device.
Note that the user can set the number of calls before receiving an incoming call automatically, and the number of calls before receiving the call can be usually set for each of the parent device and the child device. Normally, whether or not the answering machine function is on can be recognized by the user based on light emission of LEDs, LCD display, and the like in each of the parent device and the child device.

[0005]

However, in the above-mentioned conventional cordless telephone apparatus, when the answering machine function of both the base unit and the child unit is turned on, the following problem occurs. Although the answering machine function of both the base unit and the slave unit is turned on, only the side that has set a small number of calls before the automatic answering function for the answering machine function receives an incoming call and voice Make a recording.

For example, although a mark indicating that the answer phone function of the slave unit itself is on is displayed on the LCD of the slave unit, recording is performed on the master unit side. Is not performed, causing confusion for the user. If the same number of calls is automatically set for the answering function of both the master unit and the slave unit, the answering machine will automatically answer the call if there is a call from an external telephone device. In such a case, a problem may occur that the execution of the process is started.

Therefore, the present invention has been made in view of such a problem relating to the collision of the answering machine function.
An object of the present invention is to provide a parent-child telephone device that avoids a collision of an answering machine function between a parent device and a child device.

[0008]

In order to solve the above-mentioned problems, a parent-child telephone device according to the present invention is a parent-child telephone device comprising a parent device and a child device both having an answering machine function. Detecting means for detecting whether the answering function of each of the slave units is on or off,
And canceling means for changing one of the answering functions of the master unit and the slave unit to an off state when the detection unit detects that both the answering machine functions of the master unit and the slave unit are on. It is characterized by having.

With the above configuration, collision between the answering machine functions of both the master unit and the slave unit is avoided. That is, since the answering machine function of either the master unit or the slave unit is turned off, it is possible to prevent both of them from executing the process for answering machine.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a parent-child telephone device according to the present invention will be described below with reference to the drawings. <Configuration> FIG. 1 is a functional block diagram showing a configuration of a slave unit 100 of a digital cordless telephone device according to an embodiment of the present invention, and FIG. FIG. 2 is a functional block diagram showing a configuration of the apparatus 200.

Slave unit 100 of digital cordless telephone device
Is a slave unit that can also be used as a PHS portable unit, has the same appearance as a general slave unit, and has an RF / IF unit 110, a modem unit 120, a digital signal processing unit, as shown in FIG. Circuit 130, audio signal processing circuit 140, speaker 151, microphone 152, recording / playback unit 160, control unit 1
70, a key input receiving unit 181 and a display unit 182.

Here, the RF / IF unit 110 is
0 for performing frequency conversion in order to wirelessly transmit and receive a signal via an antenna.
It performs modulation and demodulation using π / 4 shift QPSK.
The digital signal processing circuit 130 performs time division multiplexing (TDM
A) is a circuit that performs digital signal processing such as A), and when control data is received from the parent device 200, extracts the control data and transmits the control data to the control unit 170, and the control data transmitted from the control unit 170 Also, a process of superimposing the transmission signal on the transmission signal is performed. Here, the control data includes, for example, control data indicating a master device status notification, and the control data indicating a master device status notification is control data including status information. The status information is either an answering machine standby state in which the answering machine function of the base unit is turned on (hereinafter, referred to as an “on state”) or an answering machine canceling state in which the answering machine function is turned off (hereinafter, referred to as “state”) "Off state").

The audio signal processing circuit 140 has an ADPCM /
This circuit performs PCM conversion, A / D conversion, and D / A conversion, and is connected to the speaker 151 and the microphone 152. The recording / reproducing unit 160 realizes an answering function such as recording an audio for about two minutes as a digital signal using an IC exclusively for recording / reproducing and reproducing the audio from the recorded digital signal.

The control unit 170 includes the digital signal processing circuit 1
30 for controlling the recording / reproducing unit 160, etc., and is composed of a memory and a microcomputer.
Answering machine related information storage unit 171, parent device state detection unit 172,
Answering machine on / off information storage unit 173, priority information storage unit 1
74 and an answer phone canceling unit 175. The answering machine related information storage unit 171 is a memory area for storing answering machine related information related to the answering machine function, and stores information such as the number of times of calling until an automatic call is received.

The parent device state detecting section 172 periodically transmits the parent device 2
By acquiring control data indicating the status notification of the base unit transmitted from 00, that is, control data including state information and the like via the digital signal processing circuit 130, the base unit 2
It has a function of detecting whether the answering machine function of 00 is on or off. The answering machine on / off information storage unit 173 is a memory area for storing 1-bit on / off information indicating whether the answering machine function of the slave unit 100 itself is on or off. This ON /
With reference to the OFF information, the control unit 170 controls whether or not to execute the answering machine function, that is, whether or not to perform the recording operation upon receiving an incoming call.

The priority information storage unit 174 is a memory area for storing 1-bit priority information indicating which of the answering functions of both the parent device 200 and the child device 100 has priority. The value indicating the parent device priority or the value indicating the child device priority is predetermined. Answering Machine Release Unit 17
5 sets the answering machine function of the cordless handset 100 to the OFF state based on a predetermined condition judgment or transmits the answering machine cancel request to the master unit 200 to control the answering machine function. It is required to be turned off.

Note that the parent machine state detecting section 172 and the answer phone canceling section 175 execute the control program stored in the memory by the microcomputer.
That function is realized. The control unit 170
, The electric field strength of the radio wave received from the base unit 200 by the RF / IF unit 110 is input. When the electric field strength is equal to or lower than a predetermined reference, the slave unit is controlled to operate in the public mode for communicating with the wireless base station.

A key input accepting unit 181 accepts a key input by a user through a numeric keypad or the like, and a display unit 182 displays a mark or the like indicating that the answering machine function is on when the answering machine function is on. Is displayed on the screen. In addition, the user can set whether or not the answering machine related information and the answering machine function are turned on or off by inputting a key to the cordless handset 100, and the control unit 170 responds accordingly. The answering machine related information stored in the answering machine related information storage unit 171 and the ON / OFF information stored in the answering machine ON / OFF information storing unit 173 are updated.

On the other hand, the base unit 200 of the digital cordless telephone device is connected to a telephone line, and transmits and receives signals to and from the slave device wirelessly via an antenna. It allows you to make calls on
As shown in FIG. 2, the line control circuit 210, the audio signal processing circuit 220, the digital signal processing circuit 230, the modem 2
40, an RF / IF unit 250, a receiver 260, a recording / reproducing unit 270, a control unit 280, and a key input receiving unit 290.

Here, the line control circuit 210 performs processing as an interface between the voice signal processing circuit 140 and the telephone line during a call, in addition to processing such as line connection at the time of calling and detection of an incoming call. The audio signal processing circuit 220 has an ADP
This circuit performs CM / PCM conversion, A / D conversion, and D / A conversion, and is connected to the receiver 260.

The digital signal processing circuit 230 is a circuit for performing digital signal processing such as time division multiplexing (TDMA). When receiving control data, the digital signal processing circuit 230 extracts the control data and transmits it to the control unit 280. , For transmitting the control data transmitted from the control unit 280 to the transmission signal. The RF / IF unit 250 is a
0 to perform frequency conversion in order to wirelessly transmit and receive signals via an antenna, and the modem 240
Modulation / demodulation by 1 / 4π shift QPSK is performed. The transmission and reception between the parent device 200 and the child device 100 is performed by ARIB (Association of Radio).
Industries and Business
s) Performed according to standards.

The recording / reproducing unit 270 implements an answering machine function of recording approximately 15 minutes of audio as a digital signal using an IC exclusively for recording / reproduction and reproducing the audio from the recorded digital signal. The control unit 280 controls the digital signal processing circuit 230, the recording / reproducing unit 270, etc., and includes a memory and a microcomputer, and functionally includes an answering machine related information storage unit 281, a state notification unit 282,
Answering machine on / off information storage unit 283, cancellation request detection unit 2
84 and an answering machine release unit 285.

The answering machine related information storage unit 281 is a memory area for storing answering machine related information related to an answering machine function, and stores information such as the number of times of calling until an automatic call is received. The answering machine on / off information storage unit 283 stores the base unit 200
This is a memory area for storing 1-bit on / off information indicating whether the answering machine function is in an ON state or an OFF state. With reference to the on / off information, the control unit 280 controls whether or not to execute the answering machine function, that is, whether or not to perform the recording operation upon receiving an incoming call.

The state notifying section 282 refers to the on / off information stored in the answering machine on / off information storage section 283 to determine whether the answering machine function of the base unit 200 is on or off. In order to notify the slave unit 100 of the status information indicating the status, the digital signal processing circuit 230 is controlled to periodically transmit the control data including the status information to the slave unit 100 to the effect that the master unit status is notified. The control data including the status information indicating the latest status is transmitted at a cycle of about one second.

FIG. 3 is a sequence chart showing a state in which control data indicating a parent device status notification is transmitted from parent device 200 to child device 100. As shown in FIG.
From 0, control data indicating a parent device state notification is transmitted to the child device 100 about every one second. Release request detection unit 284
Is for detecting that control data indicating a request for an answering machine release request has been sent from the slave unit 100, and transmitting an instruction for canceling an answering machine to the answering machine canceling unit 285.

The answering machine release unit 285 includes a release request detection unit 2
When an instruction for canceling the answering machine is transmitted by 84, the on / off information stored in the answering machine on / off information storage unit 283 is set to a value indicating the off state, and the control data indicating the completion of canceling is set as a child. The digital signal processing circuit 230 is controlled so as to be transmitted to the device 100. Also, a key input receiving unit 290
Accepts a key input by the user through a ten key or the like. It should be noted that the user is the master device 200
The answering machine related information and whether the answering machine function is turned on or off can be set by inputting a key to, and the control unit 280 stores the answering machine related information storage unit 281 in response to this. The stored answering machine related information and the on / off information stored in the answering machine on / off information storage unit 283 are updated.

Note that the child device 100 and the parent device 200 support a so-called remote function, and the child device 100 controls the parent device 200 in accordance with the operation of the child device 100 by the user, so that the recording and recording of the parent device 200 can be performed. The message recorded by the reproducing unit 270 is made available to the user operating the child device 100, and the answering function of the parent device 200 is turned on or off. Remote unit 10 by so-called remote function
When controlling the base unit 200 from 0, after exchanging data between the slave unit 100 and the base unit 200 by a remote start procedure according to a predetermined protocol, control data is transmitted from the slave unit 100, In response, master device 200 returns control data for a response, and finally exchanges data by a remote termination procedure according to a predetermined protocol.

<Operation> The operation related to the on / off state control of the answering machine function of the master unit 200 and the slave unit 100 having the above-described configuration will be described below. FIG.
It is a flowchart which shows the ON / OFF state control operation | movement about the answering machine function of 00.

As shown in FIG. 3, base unit 200 periodically transmits control data indicating the base unit status notification to handset unit 100. Each time control data indicating the above is received, the on / off state control operation shown in FIG. 4 is performed. First, the slave unit 100 detects the state of the answering machine function of the master unit 200 by the master unit state detecting unit 172, and determines whether or not the answering machine release unit 17 is on.
5 (step S11).

If the answering machine release unit 175 determines that the answering machine function of the base unit 200 is in the off state in step S11, the on / off state control operation ends. If the answering machine release unit 175 determines that the answering machine function of the base unit 200 is in the on state in step S11, the answering machine on / off information stored in the answering machine on / off information storage unit 173 is stored. It is determined whether or not the answering machine function of the slave unit 100 is on by referring to the state (step S1).
2).

If the answering machine release unit 175 determines in step S12 that the answering machine function of the slave unit 100 is in the off state, the on / off state control operation ends. If the answering machine release unit 175 determines in step S12 that the answering machine function of the cordless handset 100 is in the ON state, the answering machine release unit 175 refers to the priority information stored in the priority information storage unit 174 to refer to the master unit. It is determined whether the priority is given to the priority or the child device (step S13).

If it is determined in step S13 that the master unit has priority, the answering machine release unit 175 changes the on / off information stored in the answering machine on / off information storage unit 173 to a value indicating the off state. By updating the slave unit 100
Is turned off, and the on / off state control operation ends (step S14). If the answering machine release unit 175 determines that the slave unit has priority in step S13, the answering machine release unit 175 uses the so-called remote function to
The answering machine function of 0 is turned off, and the on / off state control operation ends (step S15).

FIG. 5 is a sequence chart showing transmission and reception of control data between slave unit 100 and master unit 200 when step S15 is executed. As shown in the figure, the answering machine release unit 175 executes the remote start procedure by controlling the digital signal processing circuit 130, and transmits control data indicating a request for answering machine cancellation to the base unit 200. After receiving the control data indicating the completion of release from master device 200, remote termination procedure is executed. Master device 200 detects the control data indicating the answering machine cancel request by canceling request detecting section 284, and records the answering machine canceling section 2.
In step 85, the on / off information stored in the answer phone on / off information storage unit 283 is updated to a value indicating an off state, and control data indicating completion of cancellation is transmitted to the slave unit 100. Therefore, in step S15, master device 200
The answering machine function is turned off.

As described above, in the digital cordless telephone device including the base unit 200 and the handset 100, when both the answering machines of the base unit 200 and the handset 100 are on, the handset 100 S14 or step S1
5 is performed, and as a result, any of the answering machine functions are automatically turned off, so that collision of the answering machine functions is avoided. For example, the answering machine function of the base unit 200 is turned on, and the slave unit 100 used in the public mode with the answering machine function turned on approaches the base unit 200 as the user moves and becomes self-owned. Assuming a scene switched to the mode, in this scene, step S11 and step S1
2 detects that both answering machines are on, and the operation of step S14 or step S15 is performed, so that one of the answering machines is automatically turned off.

Whether the answering function of the master unit or the slave unit is on or off is determined by, for example,
Is displayed by displaying a mark or the like, whereby the user can know that the answering machine function has been automatically turned off. <Supplement> Although the digital cordless telephone device according to the present invention has been described based on the embodiments, it goes without saying that the present invention is not limited to these embodiments.
That is, (1) In the present embodiment, base unit 200 is provided with handset 260 and key input receiving unit 290, but the present invention is not limited to this. It does not have to be provided. (2) In the present embodiment, the slave unit 100 determines whether the master unit or the slave unit has priority in step S13 as the on / off state control operation. However, the determination in step S14 is not performed and the operation in step S14 is always performed. Alternatively, the operation of step S15 may be performed without performing the determination. (3) The priority information described in the present embodiment does not necessarily have to be fixed, and the user may change at any time whether to give priority to the parent device or the child device. (4) When performing the operation of step S14 described in the present embodiment, the control unit 170 of the slave device 100 controls the answering function of the master device via the display unit 182 because the answering function of the master device is turned on. A message to turn off the answering machine function may be displayed. (5) In the present embodiment, slave unit 100 performs the on / off state control operation each time control data indicating a master unit state notification is received from the master unit. It is not necessary to execute the on / off state control operation in synchronization with the timing of receiving the control data to the effect.

Further, instead of the on / off state control operation shown in FIG.
When the user detects that the answering machine function is set to ON by key operation for 00, it determines whether or not the answering machine function of the base unit 200 is on. The answering machine function of the base unit 200 is turned off, or a message to the effect that the answering machine function cannot be turned on is displayed to the user, and the answering machine function of the slave unit 100 is turned off regardless of the operation of the user. If the answering machine function of the base unit 200 is off, the process of turning on the answering machine function of the slave unit 100 according to the user's operation may be performed. (6) In the present embodiment, the handset 100 performs the on / off control operation shown in FIG. 4, but it is determined that the answering machine function of each of the base unit and the handset is on. The operation of canceling the answering machine function may be performed by the master unit or may be realized by a combination of the parent and child.

[0037]

As is apparent from the above description, the parent-child telephone device according to the present invention is a parent-child telephone device comprising a parent device and a child device both having an answering machine function. For each answering machine function, detecting means for detecting whether the answering function is on or off and detecting that both answering functions of the master unit and the slave unit are on are detected by the detecting means. In this case, a release means for changing one of the answering machine functions of the master unit and the slave unit to the off state is provided.

As a result, collision between the answering machine functions of both the master unit and the slave unit can be avoided. That is, since the answering machine function of either the master unit or the slave unit is turned off, it is possible to prevent both of them from executing the process for answering machine. In addition, for example, when a mark indicating that the answering machine function of the slave unit itself is on is displayed on an LCD or the like of the slave unit, it is guaranteed that the answering machine operation is performed on the slave unit side. In other words, the user can trust the indication that the answering machine function is turned on using an LCD or an LED.

Here, the parent-child telephone device includes priority information storage means for storing priority information indicating which one of the answering function of the parent device and the answering machine function is given priority. Accordingly, the answering machine function of the non-priority one of the master unit and the slave unit may be changed to the off state. As a result, the answering machine function of the higher priority one of the master unit and the slave unit is kept on, and the answering machine function of the non-priority unit is turned off, for example, if the slave unit is given priority, Since the answering machine function of the aircraft is not automatically turned off, the user's confusion can be prevented.

Further, the parent-child telephone device may further include priority information changing means for changing the priority information according to a user's designation. This allows the user to freely specify whether to give priority to the parent device or the child device. Further, the detecting means periodically performs the detection, and the canceling means performs the change when the detecting means detects that both the answering machine functions of the master unit and the slave unit are both on. Can also be performed.

Thus, when it is detected that the answering machine function of both the master unit and the slave unit is on,
As soon as one of the answering machine functions is turned off, collision between the answering machine functions can be avoided even if the state of the answering machine function of each of the base unit and the slave unit is changed from off to on by the user. it can. Further, the handset of the parent-child telephone device according to the present invention is a handset having an answering machine function used together with a master station having an answering machine function, and the answering machine function of the master machine is in an on state or off. Parent device state detecting means for detecting whether the state is in a state, and a telephone answering function of the own device, a child device state detecting means for detecting whether the state is an on state or an off state, the parent machine state detecting means and If both the answering machine functions of the master unit and the own machine are detected to be on by the slave unit state detecting means, the answering machine function of the own machine is changed to the off state. And canceling the answering function to the off state.

Thus, when it is detected that the answering machine function of both the master unit and the slave unit is on, the slave unit turns off the answering machine function for the master unit by a conventional so-called remote function or the like. Or the answering machine function of the slave unit itself is changed to the off state, so that collision of the answering machine function can be avoided. Further, the handset of the parent-child telephone device according to the present invention is a handset having an answering machine function used together with a master station having an answering machine function, and is specified by a user who turns on the answering machine function of the own machine. Receiving means for receiving, a base unit state detecting means for detecting whether the answering function of the base unit is on or off when the designation is received by the receiving unit; and When the state detection means detects that the answering machine function of the master unit is in the off state, the enabling means for turning on the answering machine function of the own machine and the master unit state detection means, When it is detected that the answering machine function is on, either one of ignoring the designation and requesting the base unit to change the answering machine function to off state is performed. Having release means And it features.

Thus, when the user sets the answering machine function of the slave unit to the ON state, it is possible to prevent a collision between the master unit and the answering machine function of the slave unit. Here, the base unit state detection means indicates whether the answering machine function of the base unit is in an on state or an off state, and receives the on / off information transmitted from the base unit to perform the detection. The canceling means may make the request by transmitting information to the effect that the answering machine should be turned off to the master unit.

Thus, whether the answering machine function of the master unit is on or off is detected by receiving and referring to the on / off state transmitted from the master unit. Control related to ON / OFF of the answering machine function can be performed based on the state, and collision of the answering machine function can be avoided.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of a slave unit 100 of a digital cordless telephone device according to an embodiment of the present invention.

FIG. 2 is a functional block diagram showing a configuration of a base unit 200 of the digital cordless telephone device corresponding to the slave unit 100.

FIG. 3 is a sequence chart showing a state in which control data indicating a parent device status notification is transmitted from parent device 200 to child device 100;

FIG. 4 is a flowchart showing an on / off state control operation of the answer phone function of the slave unit 100;

FIG. 5 is a sequence chart showing transmission and reception of control data between the child device 100 and the parent device 200 when step S15 is executed.

[Explanation of symbols]

 Reference Signs List 100 slave unit 110 RF / IF unit 120 modulation / demodulation unit 130 digital signal processing circuit 140 audio signal processing circuit 151 speaker 152 microphone 160 recording / playback unit 170 control unit 171 answering machine related information storage unit 172 master unit state detection unit 173 answering machine ON / OFF information storage unit 174 Priority information storage unit 175 Answering machine release unit 181 Key input reception unit 182 Display unit 200 Master unit 210 Line control circuit 220 Audio signal processing circuit 230 Digital signal processing circuit 240 Modulation / demodulation unit 250 RF / IF unit 260 Handset 270 Recording / playback unit 280 Control unit 281 Answering machine related information storage unit 282 Status notification unit 283 Answering machine on / off information storage unit 284 Cancellation request detection unit 285 Answering machine cancellation unit 290 Key input reception unit

Claims (7)

[Claims] 1. A parent-child telephone device comprising a master unit and a slave unit each having an answering machine function, wherein whether the answering machine function of each of the master unit and the slave unit is on or off is determined. Detecting means for detecting, and when the detecting means detects that both the answering machine functions of the master unit and the slave unit are on, the answering function of one of the master unit and the slave unit is turned off. A parent-child telephone device comprising: a canceling means for changing. 2. The master / slave telephone apparatus further includes priority information storage means for storing priority information indicating which of the answering functions of the master device and the answering machine of the slave device has priority. 2. The parent-child telephone device according to claim 1, wherein the answering machine function of the non-priority one of the parent device and the child device is turned off. 3. The parent-child telephone device according to claim 2, wherein said parent-child telephone device further comprises priority information changing means for changing said priority information in accordance with a user's designation. 4. The detecting means performs the detection periodically, and the canceling means detects when the answering machine function of both the master unit and the slave unit is both on by the detecting unit. The parent-child telephone device according to any one of claims 1 to 3, wherein the change is performed. 5. A slave unit having an answering machine function used together with a master unit having an answering machine function, wherein the master unit detects whether the answering machine function of the master unit is on or off. Status detection means, a self-answering function, a slave unit status detection means for detecting whether the answering function is on or off, a master unit by the master unit status detection unit and the slave unit status detection unit, When it is detected that both the answering machine functions of the own machine are on, the answering machine function of the own machine is changed to the off state, and the answering machine function for the master machine is changed to the off state. And a canceling means for performing either one of the following. 6. A slave unit having an answering machine function, which is used together with a master unit having an answering machine function, wherein the receiving unit accepts a designation by a user who turns on the answering machine function of the own machine, and If the above designation is accepted,
With respect to the answering machine function of the master unit, master unit state detecting means for detecting whether the master unit is on or off, and detecting that the answer phone function of the master unit is off by the master unit state detecting unit. If the answering function is enabled, the answering function of the own device is turned on, and if the answering function of the master device is detected to be on by the master device state detecting means, A child device of a parent-child telephone device, comprising: cancellation means for performing either one of ignoring the specification and requesting the parent device to change the answering machine to the off state. 7. The master unit status detection means indicates whether the answering machine function of the master unit is on or off, and receives on / off information transmitted from the master unit to receive the information. 7. The parent-child telephone according to claim 5, wherein the detection is performed, and the cancellation unit makes the request by transmitting information to the effect that the answering machine function should be turned off to the master unit. The child unit of the device.