JPH05207106A - Cordless telephone set - Google Patents

Abstract

PURPOSE:To make it possible to arbitrarily switch a calling channel by disconnecting a radio line after a holding signal is outputted from a slave machine and switching to a new calling channel in accordance with the switch signal to be transmitted from a master machine. CONSTITUTION:When the user of a slave machine 1 performs the on-operation of a channel switch button 15 while an outside line calling is performed, a detection circuit 16 detects this and outputs a detection signal to a control part 14. The control part 14 disconnects a radio line after it outputs a holding signal to a master machine 2. The master machine 2 operates a holding circuit 25, makes the line wire a holding state and disconnects a radio connection temporarily. Afterwards, the use status of each calling channel is judged by a carrier sense circuit 27, a radio connection is performed by transmitting a switch signal to the calling channel other than the used calling channel to the slave machine 1 and the line wire holding state is released. Thus, the calling between the slave machine 1 and the outside line by a new radio channel becomes possible and a cordless telephone set capable of arbitrarily changing the calling channels can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless telephone comprising a master unit connected to a wired line and a slave unit connected to the master unit by a wireless line. The present invention relates to a cordless telephone capable of appropriately switching a call channel according to the intention of the machine user.

[0002]

2. Description of the Related Art Conventionally used cordless telephones automatically change the base unit by a certain processing procedure when changing the wireless connection frequency channel between the base unit and the handset during an outside line call. Switch the call channel between the main unit and the slave unit, or temporarily disconnect the wireless connection between the master unit and the slave unit, and then make a wireless connection using a new call channel, then dial again and call again. The method of making a call with the other party is adopted.

Here, for the purpose of mainly avoiding the radio wave interference, a detection circuit for detecting the radio wave interference, a circuit for confirming the radio wave condition of another channel during a call and the like are separately required. For the purpose of preventing eavesdropping, the call channel is automatically and constantly switched.

[0004]

As described above, among the conventional cordless telephones, those for the purpose of avoiding radio interference are complicated in terms of circuit and costly, and those for the purpose of preventing wiretapping are constantly talking. Since the channel is switched, there is a problem that the call quality is deteriorated. Moreover, the conventional cordless telephone cannot switch the call channel according to the intention of the user,
When I tried to switch, it was very inconvenient because I had to hang up and dial again.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a cordless telephone which can arbitrarily switch a call channel according to the intention of the user.

[0006]

In order to solve the above-mentioned problems, a cordless telephone of the present invention detects and detects a channel switching button for switching a communication channel in a handset and an ON operation of this channel switching button. A detection circuit that outputs a signal, disconnects the wireless circuit after outputting a hold signal to the master unit based on the detection signal from this detection circuit, and then newly updates according to a channel switching signal transmitted from the master unit. A control unit for controlling switching to a different call channel, the master unit holding circuit for putting the wired line on hold based on the hold signal from the slave unit, and an empty channel based on the hold signal. The carrier sense circuit that detects the signal and the channel switching signal to the new communication channel detected by this carrier sense circuit Transmits to the slave unit, in which a control unit for releasing the hold by the holding circuit after a switching control to the call channel is provided.

[0007]

[Function] When an external line call is made on the cordless handset, if a radio wave disturbance occurs on the call channel currently in use, when the user of the cordless handset turns on the channel switching button, the detection circuit detects and detects this. The signal is output to the control unit. The control unit outputs a hold signal to the master unit based on this detection signal, and then disconnects the wireless line.

On the other hand, when the base unit receives the hold signal from the handset unit, it operates the hold circuit to put the outside line in the hold state and temporarily disconnects the wireless connection between the base unit and the handset unit. After that, the control unit of the master unit determines the use status of each call channel by the carrier sense circuit, causes the slave unit to transmit a channel switching signal to a call channel other than the call channel that was used previously, and the call Make a wireless connection between the master unit and the slave unit on the channel. After that, the control unit releases the outside line holding state by the holding circuit. As a result, it becomes possible to make a call between the handset and the outside line on the new call channel.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an electrical configuration of a main part of a handset 1 in a cordless telephone of the present invention, and FIG. 2 is a block diagram showing an electrical configuration of a main part of a base unit 2.

In FIG. 1, an antenna 11 for transmitting and receiving signals to and from the master unit 2 has an output of a transmission circuit 12 for transmitting a voice signal and a control signal from a microphone (not shown) to the master unit 2 side, and a master unit 2. The input of the receiving circuit 13 that receives the audio signal and the control signal transmitted from the machine 2 is connected. Further, a carrier sense circuit 17 for detecting the presence or absence of carriers of each channel is connected to the receiving circuit 13,
The output of the carrier sense circuit 17 and the output of the receiving circuit 13 are guided to the control unit 14 that controls the operation of the entire slave unit 1.

The output of the channel switching button 15 is led to the detection circuit 16 which detects the ON operation and outputs a detection signal, and the output of the detection circuit 16 is led to the control unit 14.

The output of the control unit 14 is the output of the transmission circuit 12.
And the channel switching circuit 18, and the output of the channel switching circuit 18 is the transmission circuit 12 and the reception circuit 13.
It has a structure led by and.

Although not shown, the transmission circuit 1
The input of 2 and the output of the receiving circuit 13 are connected to a communication circuit, and a microphone and an earpiece are connected to the communication circuit.

In FIG. 2, an antenna 21 for transmitting / receiving a signal to / from the handset 1 has a transmitting circuit 22 for transmitting a voice signal or a control signal sent via a telephone line (not shown) to the handset 1 side. The output is connected to the input of the receiving circuit 23 that receives the audio signal and the control signal transmitted from the child device 1. Further, the receiving circuit 23 is connected to a carrier sense circuit 27 for detecting the presence / absence of carriers of each channel, and the output of this carrier sense circuit 27 and the output of the receiving circuit 23 control the operation of the master device 2 as a whole. Is guided to the control unit 24 which performs

The output of the control unit 24 is led to a holding circuit 25, a transmission circuit 22 and a channel switching circuit 28 which put an outside line in a holding state, and the output of the channel switching circuit 28 is received by the transmission circuit 22 and the receiving circuit. It has a structure led to the circuit 23.

Although not shown, the transmission circuit 2
The two inputs and the output of the receiving circuit 23 are connected to the telephone line via the speech network circuit and the hook switch.

Next, the operation of the cordless telephone having the above configuration will be described with reference to the operation flowcharts shown in FIGS. However, FIG. 3 is an operation flowchart of the child device 1, and FIG. 4 is an operation flowchart of the parent device 2.

When the user (caller) turns on the channel switching button 15 of the handset 2 during an outside line call in the handset 2 to avoid radio interference of the call channel and to prevent wiretapping, this turn-on is performed. The detection circuit 16 detects the operation and sends a detection signal to the control unit 14. Upon receiving the detection signal, the control unit 14 outputs the hold signal to the transmission circuit 12, and the transmission circuit 12 modulates the carrier with the hold signal and transmits the carrier from the antenna 11 to the base unit 2 side (step S1). , S2).

In the base unit 2, this transmission radio wave is transmitted to the antenna 21.
The signal is received by the receiving circuit 23 via, and the received radio wave is demodulated to the original hold signal and output to the control unit 24. Based on this hold signal, the control unit 24 outputs a hold ON signal to the hold circuit 25 to put the outside line currently in communication into a hold state (steps S21 and S22). After that, the control unit 24 of the parent device 2 outputs a hold completion signal indicating that the hold signal has been received to the transmission circuit 22, and the transmission circuit 22 modulates the carrier with the hold completion signal and outputs the hold signal from the antenna 21. It is transmitted to the machine 1 side (step S23).

In the slave unit 1, this transmission radio wave is transmitted to the antenna 11
The signal is received by the receiving circuit 13 via, and the received radio wave is demodulated to the original hold completion signal and output to the control unit 14.
The control unit 14 outputs a transmission stop signal to the transmission circuit 12 based on the suspension completion signal, and the transmission circuit 12 modulates the carrier with the transmission stop signal and transmits the carrier from the antenna 11 to the master unit 2 side (step S3, S4). After that, the transmission circuit 12 stops the transmission (step S5), shifts from the communication channel until then to the control channel, and waits for the reception of a signal from the base unit 2 (step S5).
6).

In the base unit 2, this transmission radio wave is transmitted to the antenna 21.
The signal is received by the receiving circuit 23 via, and the received radio wave is demodulated into the original transmission stop signal and output to the control unit 24.
The control unit 24, based on this transmission stop signal, transmits the transmission circuit 2
2 is stopped (steps S24 and S25). As a result, the wireless connection between the child device 1 and the parent device 2 is disconnected.

After that, the base unit 2 outputs to the channel switching circuit 28 an instruction signal indicating a call channel (for example, 2 channels) that is one higher than the call channel (for example, 1 channel) which has been in communication until then. On the basis of this instruction signal, the channel switching circuit 28 outputs a channel switching signal to the receiving circuit 23 to switch the received call channel from the previous channel 1 to channel 2 (designated call channel) (steps S26 and S27).
Then, the antenna 21, the receiving circuit 23, and the carrier sense circuit 27 detect the presence or absence of two-channel carriers, and output the detection signal to the control unit 24.

Based on this detection signal, the control unit 24
Whether or not there is a carrier for the channel is determined (step S2
8) If there is a carrier, the reception call channel is switched from the previous two channels to the third channel (designated call channel) (steps S29, S26, S).
27). Then, the carrier sense circuit 27 detects the presence / absence of carrier on three channels, and outputs the detection signal to the control unit 24. The control unit 24 repeats such a loop until it determines in step S28 that there is no carrier.

If it is determined that there is no carrier when there are four communication channels, the control section 24
A control channel change instruction signal is output to the channel switching circuit 28, and the receiving circuit 23 is switched to the control channel. Then, the carrier of the control channel is confirmed by the carrier sense circuit 27, and if there is a carrier, it waits until the control channel becomes empty. Also,
When detecting the absence of carrier and confirming that the control channel is empty, the control unit 24 outputs a transmission ON signal to the transmission circuit 22 and drives the transmission circuit 22 (step S30).

Next, the control section 24 outputs its own ID code and the channel code indicating the four channels which have been confirmed to be empty to the transmission circuit 22, and the transmission circuit 22 modulates this ID code and the channel code. To the slave unit 1 side. After that, the control unit 24 outputs an instruction signal indicating the communication channel (4 channels) designated by the transmitted channel code to the channel switching circuit 28, and the channel switching circuit 28 receives the instruction circuit 23 based on the instruction signal. Then, a channel switching signal is output to the transmission circuit 22 to switch the reception communication channel and the transmission communication channel to the designated communication channels (4 channels) (step S31).

After the transmission is stopped in step S5, the slave unit 1
In step S6, the transition to the control channel has already been made, and the presence or absence of carriers in the control channel is constantly monitored (step S7). Therefore, the handset 1 receives the radio wave transmitted by the control channel from the base unit 2 in the receiving circuit 13 via the antenna 11, demodulates the received radio wave into the original ID code and channel code,
Output to the control unit 14. When the control unit 14 confirms that the transmitted ID code of the base unit 2 matches its own ID code (step S8), it sends an instruction signal indicating the call channel (4 channels) designated by the channel code. Based on this instruction signal, the channel switching circuit 18 outputs a channel switching signal to the reception circuit 13 and the transmission circuit 14 to output the reception call channel and the transmission call channel to the designated call channel ( 4 channels) (step S9).

After that, the control unit 14 outputs a channel switching completion signal to the transmission circuit 12, and the transmission circuit 12 modulates the carrier with the channel switching completion signal and transmits it from the antenna 11 to the base unit 2 side ( Steps S10 and S
11).

In the base unit 2, this transmission radio wave is transmitted to the antenna 21.
The signal is received by the receiving circuit 23 via the, and the received radio wave is demodulated to the original channel switching completion signal and output to the control unit 24 (step S32). Based on the channel switching completion signal, the control unit 24 outputs a hold release signal to the hold circuit 25 to release the outside line holding state (step S33).

As a result, the call between the handset and the outside line is restarted via the new call channel.

[0031]

The cordless telephone of the present invention can be used as a cordless handset.
After the channel switching button that switches the call channel, the detection circuit that detects the ON operation of this channel switching button and outputs a detection signal, and after outputting the hold signal to the master unit based on the detection signal from this detection circuit A control unit that disconnects the wireless line and controls switching to a new communication channel according to the channel switching signal transmitted from the master unit is provided, and the master unit is wired based on the hold signal from the slave unit. A hold circuit that puts the line in a hold state, a carrier sense circuit that detects an empty channel based on the hold signal, and a channel switching signal to a new communication channel detected by the carrier sense circuit are transmitted to the slave unit. , And a control unit for canceling the hold state by the hold circuit after controlling the switching to the call channel. Since a configuration, it is possible to realize a cordless telephone that can arbitrarily change the speech channel by the user's intention by a simple circuit structure. In addition, the problem that the circuit is complicated and costly like the conventional telephone for the purpose of avoiding radio interference, and the call quality by constantly switching the call channel like the conventional telephone for the purpose of preventing wiretapping. A problem such as a decrease in power is avoided.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a main part of a slave unit in a cordless telephone of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of a main part of a base unit in the cordless telephone of the present invention.

FIG. 3 is a flowchart illustrating an operation of a control unit of a child device.

FIG. 4 is a flowchart illustrating an operation of a control unit of the parent device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Slave device 2 Master device 14 Control part 15 Channel switching button 16 Detection circuit 17 Carrier sense circuit 24 Control part 25 Reservation circuit 27 Carrier sense circuit

Claims (1)

[Claims] 1. A cordless telephone comprising a master unit connected to a wired line and a slave unit connected to the master unit via a wireless line, wherein the slave unit has a channel switching button for switching a call channel. And a detection circuit for detecting the ON operation of this channel switching button and outputting a detection signal, and after disconnecting the wireless line after outputting a hold signal to the base unit based on the detection signal from this detection circuit, And a control unit that controls switching to a new communication channel according to a channel switching signal transmitted from the master unit, and the master unit is provided with the wired line based on a hold signal from the slave unit. A holding circuit that puts the device in a holding state, a carrier sense circuit that detects an empty channel based on the holding signal, and a carrier sense circuit that detects the empty channel. A control unit for transmitting a channel switching signal for the new call channel to the slave unit and for canceling the hold state by the hold circuit after performing the control for switching to the call channel. Cordless phone.