JP2997663B2 - Line connection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line connection suitable for interconnecting a transmission signal line and a reception signal line connected to a half-duplex or simplex wireless device and a two-wire telephone line. It concerns the device.

[0002]

2. Description of the Related Art As shown in FIG. 4, a line connection device used in a communication system S11 capable of interconnecting a radio device and a telephone has a hybrid transformer therein.
A line connection device 51 including a W / 4W conversion circuit 52 and a tone detection circuit 53 is conventionally known. In this case, the 2W / 4W conversion circuit 52 includes a two-wire telephone line 12 connected to the push-button telephone 11 and a transmission signal line as a four-wire signal line connected to the simplex type wireless device 3. 15 and the reception signal line 16 are mutually connected. Further, the tone detection circuit 53 includes a predetermined DTMF (Dual Tone Multi-Freq) together with the voice signal from the telephone 11.
so-called “Press-To-Talk” for detecting the DTMF signal when the signal is transmitted and controlling the radio 3 in the transmission state at the time of the detection.
The signal is used as the transmission control signal SPTT as the transmission control signal line 17
Is output to the wireless device 3 via.

In the communication system S11, for example, when a push button "#" of the telephone 11 is operated,
A corresponding DTMF signal is transmitted to the line connection device 51 via the telephone line 12. Next, the 2W / 4W conversion circuit 52 of the line connection device 51 outputs the DTMF signal as the transmission signal TAF to the transmission signal line 15 via the hybrid transformer. In this case, the tone detection circuit 53 detects a DTMF signal corresponding to the code "#", and outputs a transmission control signal SPTT to the transmission control signal line 17 upon detection. Thereby, the wireless device 3 is controlled to the transmission state. Next, when the speaker of the telephone 11 emits a voice to the transmitter, the voice signal is transmitted to the 2W / 4W conversion circuit 52 via the telephone line 12. 2W / 4W
The conversion circuit 52 outputs the audio signal to the transmission signal line 15 as the transmission signal TAF in the same manner as the DTMF signal. As a result, the transmission signal TAF is output to the wireless device 3 and radiated from the antenna 4 as a wireless signal. On the other hand, the portable wireless device 5 receives a wireless signal via the antenna 6 and
The radio signal is demodulated into the original transmission signal TAF. As a result, the transmission signal TAF output from the telephone 11 is emitted from a speaker (not shown) of the portable wireless device 5.

Next, when the push button "*" is operated on the telephone 11, a corresponding DTMF signal is output to the tone detection circuit 53 via the telephone line 12 and the 2W / 4W conversion circuit 52. At this time, the tone detection circuit 53 detects the DTMF signal corresponding to the code "*", and stops the output of the transmission control signal SPTT upon detection. Thereby, the wireless device 3 is controlled to the receiving state. Next, when the speaker on the side of the portable wireless device 5 emits a voice to the transmitter, the portable wireless device 5 radiates a wireless signal modulated by the voice from the antenna 6. This allows
The wireless device 3 demodulates the received wireless signal and transmits the demodulated received signal RAF via the received signal line 16 to 2W / 4.
The signal is output to the W conversion circuit 52. At this time, the 2W / 4W conversion circuit 52 receives the received signal R via the hybrid transformer.
The AF is output to the telephone line 12. As a result, mutual communication is performed between the telephone 11 and the portable wireless device 5.

[0005]

However, the conventional line connection device 51 has the following problems. That is,
In this line connection device 51, a predetermined DT
When the MF signal is transmitted, the wireless device 3 is automatically controlled to a transmission state or a reception state. On the other hand, unlike the two-wire telephone, the wireless device 3 is of a simplex type, so that the voice from the speaker of the telephone 11 and the voice of the other party cannot be simultaneously communicated in two directions. . Therefore, since the speaker of the telephone 11 cannot immediately confirm the response of the other party to his / her own voice, he / she must talk in a state of suspicion whether or not his / her own voice is actually transmitted. Thus, the line connection device 51 has a problem that it is difficult for the speaker of the two-wire telephone to confirm whether the wireless device 3 is in the transmission state or the reception state. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and it is possible to make a speaker of a two-wire telephone easily recognize whether a wireless device is in a transmitting state or a receiving state. A main object is to provide a possible line connection device.

[0007]

According to a first aspect of the present invention, there is provided a line connection apparatus comprising: a transmission signal line and a reception signal line connected to a half-duplex or simplex wireless device; A two-wire / four-wire conversion circuit for interconnecting a telephone line, detecting a transmission signal sent from the two-wire telephone line to a transmission signal line, and controlling the wireless device to be in a transmission state upon detection. in the line connection unit and a transmission control signal generation circuit for generating a transmission control signal for, when outputting the transmission control signal to the wireless device, with sending the first predetermined sound signals to the reception signal line, a wireless Equipment
When the transmission control signal output is stopped, the first predetermined sound signal is output.
Is a second predetermined sound that differs at least in part of the frequency components
A signal output circuit for outputting a signal to a reception signal line is provided.

In this line connection device, when a transmission signal is transmitted from the two-wire telephone line side, the transmission control signal generated by the transmission control signal generation circuit is output to the wireless device. At this time, the signal output circuit connects the first
, And the first predetermined sound signal is transmitted from the reception signal line to the two-wire telephone line via a two-wire / four-wire conversion circuit. Therefore, the speaker of the two-wire telephone is set in the transmission state by transmitting a predetermined sound based on the first predetermined sound signal from the receiver, and the own voice is transmitted to the other party. Can be easily recognized.

[0011] In the line connection unit, the output of the transmission signal from the two-wire telephone line is stopped, the transmission control signal generation circuit stops generating the transmission control signal. At this time, the signal output circuit sends a second predetermined sound signal to the reception signal line, and the second predetermined sound signal is transmitted from the reception signal line to the two-wire telephone line via the two-wire / four-wire conversion circuit. Will be sent out. In this case, since at least a part of the frequency component of the second predetermined sound signal is different from the frequency component of the first predetermined sound signal, the speaker of the two-wire telephone can perform the predetermined operation based on the second predetermined sound signal. Since the sound is emitted from the receiver, it is possible to easily recognize that the wireless device is controlled to the reception state.

[0010] The line connection device according to the second aspect is the first aspect.
In the line connection device described above , the signal output circuit stops outputting at least one of the first and second predetermined sound signals when a predetermined control signal is sent from the two-wire telephone line side. It is characterized by.

[0011] A speaker unfamiliar with a telephone call via the wireless device can easily recognize the transmission / reception state of the wireless device by emitting predetermined sounds based on the first and second predetermined sound signals from the receiver. can do. On the other hand, it may not be necessary for a speaker who is accustomed to talking via the wireless device. In this line connection device, a speaker of a two-wire telephone operates, for example, a push button to perform DTMF.
When the signal is transmitted as a control signal, the signal output circuit stops outputting any one or more predetermined sound signals of the first and second predetermined sound signals according to the type of the control signal. Therefore, the speaker can stop the output of any given sound signal at any time according to the degree of familiarity with the call.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a line connection device according to the present invention will be described below with reference to the accompanying drawings.

FIG. 3 shows a system diagram of the telephone line system Sa. As shown in FIG.
Are connected to the public line network PT via the telephone line 12, and are connected to a plurality of private communication systems S which are substantially the same.
1, S2,... (In the figure, two private communication systems S
1 and S2 only, and the private communication system S1 will be described below as a representative).
1, S2,... Are configured to include a semi-duplex or simplex portable radio device 5 which can be interconnected via a radio line.

The private communication system S1 includes a line connection device 1
A private branch exchange 2 called a PBX, a half-duplex or simplex FM radio 3 corresponding to a radio device in the present invention, for example, using VHF, and a plurality of telephones 11, 11 for extension. .. And an attached telephone 14 installed at the installation location of the line connection device 1.

In the private communication system S 1, when a call is made from the telephone 11 to the portable wireless device 5, the telephone 11 and the line connection device 1 are interconnected by the private branch exchange 2 via the extension 13. At this time, the line connection device 1 calls the portable wireless device 5 to connect the line between the wireless device 3 and the portable wireless device 5 via the wireless line.
Next, the line connection device 1 interconnects the two-wire extension line 13 with the four-wire signal line including the transmission signal line 15 and the reception signal line 16 connected to the wireless device 3. As a result, the telephone 11 that has made the call and the portable wireless device 5 are interconnected via the wireless line. On the other hand, when a call is made from the portable wireless device 5 to the telephone 11 or the public line network PT, first, the portable wireless device 5 and the line connection device 1 are connected via the wireless line and the wireless device 3. Are connected to each other. Next, the line connection device 1 connects the private branch exchange 2 and the portable wireless device 5 to each other via the extension 13, and sends out the DTMF signal transmitted from the portable wireless device 5 to the private branch exchange 2. As a result, the private branch exchange 2 connects to the telephone 11 or the public line network PT corresponding to the DTMF signal transmitted from the portable wireless device 5, and as a result, the portable wireless device 5 and any telephone 11 or the public line network PT are connected. Is connected to any telephone line.

Further, in this local communication system S1, interconnection between other local communication systems S2, S3,... Is also possible. Specifically, for example, the private communication system S
2 to the local telephone system S1
When there is a call from the telephone 11 in the private network, first, the private branch exchange 2 in the private communication system S1 interconnects the telephone 11 and the line connection device 1 in the private communication system S1 via the extension 13. I do. Next, the line connection device 1 connects the wireless device 3 in its own communication system to the wireless device 3 in the local communication system S2 via a wireless line. Next, the line connection device 1 in the private communication system S2 connects to the called telephone 11 through the private branch exchange 2 in the private communication system S2. As a result, the calling telephone 11 connects the private branch exchange 2, the line connection device 1, and the radio device 3 in the private communication system S1, and the radio device 3, the line connection device 1, and the private branch exchange 2 in the private communication system S2. Is connected to the telephone 11 on the called side.

Next, a specific configuration of the line connection device 1 will be described with reference to FIG.

As shown in FIG. 1, a line connection device 1 includes a connection box 21, an NCU 22, a CPU 23 corresponding to a signal output circuit in the present invention, VOX circuits 24 and 25, delay circuits 26 and 27, and a DTMF signal detection circuit 28. , DTM
F signal generation circuit 29, voice synthesis circuit 30, speaker 31
And a priority setting switch 32.

The connection box 21 normally has N
When the CU 22 and the attached telephone 14 are connected to the extension 13 and the attached telephone 14 is off-hook, an off-hook signal SH is output to the CPU 23, and as described later,
When the on-hook control signal SHC is output from the CPU 23, the connection between the extension 13 and the attached telephone 14 is released.
The NCU 22 includes a 2W / 4W conversion circuit 52 composed of a hybrid transformer or an operational amplifier, a connection switch 3
3 and a signal detection circuit 34. Where 2W
The / 4W conversion circuit 52 connects the four-wire signal line composed of the transmission signal line 15 and the reception signal line 16 connected to the wireless device 3 to the two-wire extension line 13, and sends out from the extension line 13. Transmission signal line 15
To the wireless device 3 via the reception signal line 16.
Is transmitted to the extension 13.
The connection switch 33 is controlled by the CPU 23 to
The extension 13 is connected to the 2W / 4W conversion circuit 52. Further, the signal detection circuit 34 detects various signals sent out via the extension 13, and outputs the detected various signals to the CP.
Output to U23. The CPU 23 plays a core role in the line connection device 1 and executes a line connection process described later. The VOX circuit 24 is disposed in the middle of the transmission signal lines 15, 15 connecting the NCU 22 and the radio device 3, and detects the transmission audio signal sent to the transmission signal line 15, thereby setting the radio device 3 in a transmission state. To generate a transmission control signal SPTT for controlling the transmission. The VOX circuit 25 is provided in the middle of the reception signal lines 16, 16 connecting the NCU 22 and the radio 3, and receives the reception signal line 1.
6, a reception sound signal SRA for prohibiting the output of the transmission control signal SPTT to the radio device 3 is generated by detecting the reception voice signal sent from the radio device 3 to the CPU 3.
23.

The delay circuit 26 is connected to the transmission signal line 15.
The transmission signal TAF transmitted from the wireless device 3 is delayed by a predetermined time to prevent the transmission signal TAF transmitted from the wireless device 3 from being truncated, and the delay circuit 27 converts the reception signal RAF transmitted to the reception signal line 16 into a predetermined signal. By delaying the time,
The head of the received signal RAF when sending out to the extension 13 is prevented. The DTMF signal detection circuit 28 detects a DTMF signal transmitted from the portable wireless device 5 via a wireless line, and outputs a digital signal SD corresponding to the DTMF signal to the CPU.
23. The DTMF signal generation circuit 29 includes a CPU
DTMF according to the generation command signal SDT output from
A signal is generated and sent to the reception signal line 16. The voice synthesizing circuit 30 sends an end signal SE to the wireless device 3 via the transmission signal line 15 or outputs a predetermined alarm sound signal SA to the speaker 31 according to a control command of the CPU 23. The priority setting switch 32 is used to set which of the co-located telephone 14 and the portable wireless device 5 is preferentially connected to the extension 13 as described later.

Next, the line connection processing in the line connection device 1 will be described.

First, a process for connecting the portable radio 5 and the telephone 11 in response to an outgoing call as a connection request from the portable radio 5 will be described. First, on the portable radio 5 side, the press talk switch is operated to put the portable radio 5 in the transmission state, and then the push button is operated. As a result, the wireless signal modulated by the DTMF signal is input to the wireless device 3 via the antennas 6 and 4. Next, the wireless device 3 demodulates the received wireless signal,
The demodulated DTMF signal is output to the line connection device 1 via the reception signal line 16 as the reception signal RAF. On the other hand, in the line connection device 1, the VOX circuit 25 detects a predetermined frequency component included in the received signal RAF, and outputs a received sound detection signal SRA to the CPU 23 upon detection. In this case, CP
U23 stops outputting the transmission control signal SPTT to the wireless device 3. Therefore, the reception signal RAF leaked to the transmission signal line 15 via the 2W / 4W conversion circuit 52 in the NCU 22, and the transmission control signal SPTT was output from the VOX circuit 24 by detecting the leaked reception signal RAF. Even in this case, the output of the transmission control signal SPTT from the CPU 23 to the wireless device 3 is stopped. Also, DTMF
The signal detection circuit 28 detects the DTMF signal,
Digital signal SD corresponding to the DTMF signal is
Output to U23.

Next, when the CPU 23 inputs the digital signal SD as the connection request detection signal, the NCU 22
By outputting an ON signal SON, the connection switch 33 is turned on. Thereby, NCU2
2, the extension 13 via the 2W / 4W conversion circuit 52 in
The transmission signal line 15 and the reception signal line 16 are mutually connected. Next, the CPU 23 outputs a generation command signal SDT to the DTMF signal generation circuit 29 to generate a DTMF signal corresponding to the input digital signal SD. As a result, the DTMF signal generation circuit 29
F signal is generated, and the DTMF signal is
It is sent to the private branch exchange 2 via the 6, 2W / 4W conversion circuit 52 and the extension 13. Next, the private branch exchange 2
A ringing tone is output to the telephone 11 of the dial number corresponding to the DTMF signal. When a call is made from the portable wireless device 5 to the public line network PT, the private branch exchange 2 sends a DTMF signal to the public line network PT. When a ringing tone is output to the telephone 11, a ring back tone (RBT) is sent from the private branch exchange 2 to the extension 13, and the ring back tone is transmitted to the NC via the 2W / 4W conversion circuit 52.
The signal is output to the signal detection circuit 34 in U22. The signal detection circuit 34 detects a ring back tone, and outputs a ring back tone detection signal S RB to the CPU 23 upon detection. Next, the CPU 23 generates a pseudo ringback tone using the event timer, sends out the generated pseudo ringback tone signal SRBQ to the wireless device 3 via the transmission signal line 15, and transmits the transmission control signal line 1
7 to output a transmission control signal SPTT to the wireless device 3.
As a result, the wireless device 3 sets the pseudo ringback tone signal S
As a result of transmitting the wireless signal modulated by the RBQ to the portable wireless device 5, the portable wireless device 5 emits a ringback tone based on the pseudo ringback tone signal SRBQ,
The speaker can recognize that a call is being made.

Next, the telephone 11 is connected off-hook to the portable radio 5 via the private branch exchange 2, the line connection device 1 and the radio 3. At this time, since the output of the ring back tone signal S RB from the private branch exchange 2 is stopped, the CPU 23 stops the output of the pseudo ring back tone signal S RBQ, and as a result, the ring back tone is emitted on the portable radio device 5 side. The sound is also stopped. Next, when the speaker of the telephone 11 utters a voice to the transmitter, the voice signal is output to the extension 13 and the NCU.
VOX circuit 2 via 2W / 4W conversion circuit 52 in
4 is input. In this case, the VOX circuit 24 detects a predetermined frequency component included in the audio signal, and outputs a transmission control signal SPTT to the CPU 23 upon detection. At this time, since the reception signal RAF has not been sent to the reception signal line 16 and the reception sound detection signal SRA has not been input, the CPU 23 sends the transmission control signal SPTT to the radio 3 via the transmission control signal line 17. Output. This allows
The wireless device 3 enters a transmission state, and the transmission signal TAF is transmitted to the portable wireless device 5. In this case, the audio signal as the transmission signal TAF sent to the transmission signal line 15 is sent to the wireless device 3 after being delayed by the delay circuit 26 by the time required for the sound detection by the VOX circuit 24. Therefore, the transmission signal TAF is transmitted to the portable wireless device 5 via the wireless device 3 without truncation.

At the same time, when the transmission control signal SPTT rises, the CPU 23 generates a first predetermined sound signal S1 by the event timer and sends out the generated first predetermined sound signal S1 to the reception signal line 16. As a result, the first predetermined sound (for example, a beep) is emitted from the speaker of the telephone 11, so that the speaker can recognize that the speaker is currently transmitting. The CPU 23 may continuously output the first predetermined sound signal S1 to the telephone 11 while outputting the transmission control signal SPTT. In this case, when a predetermined push button (for example, “#”) is operated on the telephone 11 side, the signal is detected by the signal detection circuit 34 in the NCU 22 and the detection signal ST is output by the CPU.
23. In such a case, the CPU 23 outputs the first predetermined sound signal S1 to the telephone 11 only when the transmission control signal SPTT rises. Also, the CPU 23
When the transmission control signal SPTT falls, the event timer sends out a second predetermined sound signal S2 having a frequency component different from that of the first predetermined sound to the reception signal line 16. Thereby, the second predetermined sound (for example, from the speaker of the telephone 11)
When the beep is emitted, the speaker can hear the radio 3
Can be recognized from the transmission state to the reception state.

During a conversation, the CPU 23
Whenever the reception signal RAF is output from the circuit 25, the output of the transmission control signal SPTT to the radio 3 is stopped to maintain the reception state of the radio 3, and conversely, the VOX circuit 24
When the transmission control signal SPTT is output from the VOX circuit 25, the reception of the reception sound detection signal SRA from the VOX circuit 25 is prohibited, so that the wireless device 3 is maintained in the transmission state. As a result, the wireless device 3 can be appropriately controlled to one of the transmission state and the reception state, and the 2W / 4 of the reception signal RAF can be obtained.
Erroneous output of the transmission control signal SPTT due to leakage through the W conversion circuit 52 is prevented, and thereby erroneous transmission control for the wireless device 3 is prevented.

When the conversation is completed and the telephone 11 goes on-hook, a ringing tone is output from the private branch exchange 2 via the extension 13.
The data is sent to the W / 4W conversion circuit 52. In this case, 2W
The / 4W conversion circuit 52 sends out the ringing tone to the transmission signal line 15 as the transmission signal TAF, and the VOX circuit 24 detects this, and at the time of the detection, converts the transmission control signal SPTT to C
Output to PU23. As a result, the CPU 23 outputs the transmission control signal SPTT to control the radio 3 in the transmission state. As a result, the call termination sound is transmitted to the portable wireless device 5 via the wireless device 3 and emitted from the speaker of the portable wireless device 5. Thus, the speaker of the portable wireless device 5 can recognize that the telephone 11 has been hooked on. The signal detection circuit 34 in the NCU 22
The end call sound is detected, and at that time, the end sound detection signal S
TE is output to the CPU 23. The CPU 23 outputs the off signal HOFF to the NCU 22 and controls the connection switch 33 to the off state when the time of, for example, about 5 seconds elapses from the input of the end-of-call detection signal STE, thereby controlling the extension 13
And the connection with the 2W / 4W conversion circuit 52 is cut off. In addition,
If the private branch exchange 2 does not output the ringing tone, the NC
A polarity inversion detection circuit (not shown) in the U22 monitors the polarity of the extension 13 and when the polarity is inverted, the CPU 23
Outputs the polarity inversion detection signal SP. When the private branch exchange 2 does not output the ringing tone and the polarity is not inverted, the CPU 23 monitors the output status of the transmission control signal SPTT from the VOX circuit 24 and waits for a predetermined time (for example, 3 seconds).
If the transmission control signal SPTT is not output for 0 seconds), it is determined that the telephone 11 is on-hook, and the off signal SOFF is output, whereby the connection switch 33 is output.
Is turned off.

On the other hand, for example, when connected to a line for time signal guidance or weather forecast in the public line network PT, the line does not go on-hook. Need to be able to shut off. In this case, when the portable wireless device 5 continuously operates, for example, the code “#” of the push button, the DTMF signal, which is the code signal, is transmitted to the reception signal line 16 via the wireless device 3. At this time, the DTMF signal detection circuit 28 detects this and outputs a digital signal SD corresponding to the code "#" to the CPU 23. At this time, C
The PU 23 controls the connection switch 33 to the off state by outputting the off signal SOFF to the NCU 22. As a result, the connection between the portable wireless device 5 and the public network PT is cut off. Further, after outputting the off signal SOFF, the CPU 23 causes the voice synthesizing circuit 30 to generate the end signal SE and outputs the transmission control signal SPTT to the transmission control signal line 17. Thus, the wireless device 3 is controlled to the transmission state and transmits the end signal SE. As a result, the speaker of the portable wireless device 5 can recognize that the connection with the public line network PT has been interrupted by emitting the end sound from the speaker.

Next, a process for connecting the telephone 11 and the portable radio device 5 in response to a call from the telephone 11 will be described. First, by operating the push button on the telephone 11 in an off-hook state, a ringing tone is sent from the private branch exchange 2 to the line connection device 1. At this time, the signal detection circuit 34 in the NCU 22 detects a ringing tone and outputs a ringing tone detection signal SR to the CPU 23. Next, the CPU 23 sends an ON signal SON to the NCU 22.
To control the connection switch 33 to the on state. Thus, the extension 13 and the transmission signal line 15 and the reception signal line 16 are mutually connected via the 2W / 4W conversion circuit 52 in the NCU 22. Thereafter, the process is performed in the same manner as the above-described line connection process.

Next, processing when the attached telephone 14 is in use will be described.

In the line connection device 1, the attached telephone 14
Is connected to the extension 13 in the connection box 21 in a normal state. Therefore, the attached telephone 14 can be connected to another telephone 11 via the private branch exchange 2 in the same manner as the extension telephone 11. On the other hand, telephone 1
When the portable wireless device 5 is used continuously, when the portable wireless device 5 makes a call as a line connection request, the line connection between the portable wireless device 5 and the telephone 11 via the wireless device 3 is established. That is, the portable wireless device 5 cannot recognize whether the attached telephone 14 is in use or the line connection device 1 is out of order. In this line connection device 1, when a call is made from the portable wireless device 5 while the off-hook signal SH is being output from the connection box 21, the CPU 23 sends the transmission control signal SPTT to the transmission control signal line 17. At the same time, an in-use communication signal SBT indicating that the attached telephone is in use is sent to the reception signal line 16.
Thus, the speaker of the portable wireless device 5 can recognize that the attached telephone 14 is currently in use and the line cannot be connected by emitting a predetermined signal sound from the speaker.

On the other hand, when the speaker of the portable radio 5 wants to make an emergency call to the predetermined telephone 11,
Is operated, a DTMF signal corresponding to that number is transmitted to the radio 3
Is transmitted to the reception signal line 16 as a reception signal RAF. At this time, the DTMF signal is detected by the DTMF signal detection circuit 28.
A digital signal SD corresponding to the F signal is output to the CPU 23. In this case, the CPU 23
, An alarm sound signal SA is generated, and the alarm sound is emitted from the speaker 31. In this case, the content of the alarm sound can be determined as appropriate, but for example, "The portable wireless device received a connection request. Please go on-hook."
Is made to synthesize the contents. Thereby, the attached telephone 14
Can immediately recognize that fact. The alarm is not limited to the emission of the alarm sound, and an alarm in text may be displayed on an LCD panel or the like. Further, by transmitting the alarm sound signal SA to the reception signal line 16, it is possible to talk to the co-located telephone 14 and the other party of the co-located telephone 14 via the extension 13.

When a predetermined push button (for example, the number “1”) is continuously operated for a predetermined time on the portable wireless device 5, the DTMF signal corresponding to the number is detected by the DTMF signal detection circuit 28. The digital signal SD corresponding to the detected DTMF signal is continuously output to the CPU 23 for a predetermined time. In this case, the CPU 23 outputs the on-hook control signal SHC to the connection box 21 to forcibly release the connection between the extension 13 and the attached telephone 14 and outputs the on-signal SON. The connection switch 33 is turned on. Thereby, the transmission signal line 15 and the reception signal line 16 and the extension 13 are connected to each other. Then, by operating the push button on the portable wireless device 5 side, it is possible to mutually connect with an arbitrary telephone 11 or a telephone in the public line network PT. In this example,
Although the portable wireless device 5 is configured to be preferentially connected to the extension 13, it is also possible to give priority to the co-located telephone 14 by operating the priority setting switch 32. In this case, even when the digital signal SD corresponding to the number "1" is continuously input, the CPU 23 does not output the on-hook control signal SHC and connects the extension telephone 14 and the extension 13 with each other. Stay connected.

The present invention is not limited to the above embodiment. For example, in the embodiment of the present invention, in order to prevent erroneous transmission control for the wireless device 3 due to leakage of the reception signal RAF to the transmission signal line 15 side, when the reception sound detection signal SRA is detected, the CPU 23 Although the output of the transmission control signal SPTT to the wireless device 3 is stopped,
By adopting the configuration shown in (1), erroneous transmission control for the wireless device 3 can be prevented.

As shown in FIG.
In this example, the echo canceller 42 is disposed between the 2W / 4W conversion circuit 52 and the transmission signal line 15 and the reception signal line 16, and the provision of the VOX circuit 25 in the line connection device 1 is omitted. In the line connection device 41, when the reception signal RAF leaks to the transmission signal line 15, the echo canceller 42 outputs a signal having the same frequency component as the reception signal RAF sent to the reception signal line 16 to the transmission signal line 15. Fifteen
, The signal superimposed on the transmission signal line 15 is removed based on the reception signal RAF. Therefore, the received signal R via the 2W / 4W conversion circuit 52
Since the leakage of the AF is prevented, it is possible to reliably prevent the VOX circuit 24 from erroneously outputting the transmission control signal SPTT due to the leaked received signal RAF.

In the embodiment of the present invention, the first predetermined sound signal S1 is sent to the reception signal line 16 when the transmission control signal SPTT rises, and the first predetermined sound signal S1 is output while the transmission control signal SPTT is being output. Although the example in which the predetermined sound signal S1 is continuously transmitted has been described, the predetermined sound signal to be transmitted while the transmission control signal SPTT is being output is different from the first predetermined sound signal in frequency and sound quality. Needless to say, the predetermined sound signal may be any type. Further, the frequencies of the first predetermined sound signal S1 and the second predetermined sound signal S2 are not limited, and a sound may be transmitted. By transmitting the DTMF signal as a control signal, the first and second signals are transmitted.
The transmission of the predetermined sound signal can also be stopped.

[0037]

As described above, according to the line connection device of the first aspect, when the signal output circuit outputs the transmission control signal to the radio device, the first predetermined sound signal is output to the reception signal line. <br/> and out feed, when the output stop of the transmission control signal to the wireless device
The first predetermined sound signal is at least a part of a frequency component.
By also be output from a different second predetermined sound signals to the reception signal line, relative to 2-wire telephone speaker, the wireless device is controlled in any of the state of the transmission <br/> state and reception state whether there can be easily recognized. This allows the speaker to talk with confidence while recognizing that his or her voice is being transmitted to the other party.

Further, according to the line connecting device according to claim 2, by the speaker transmits a predetermined control signal, according to the degree of familiarity of the call, at any time, the first and second
The output of an arbitrary signal of the two predetermined sound signals can be stopped.

[Brief description of the drawings]

FIG. 1 is a block diagram of a line connection device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a line connection device according to another embodiment of the present invention.

FIG. 3 is a system diagram of a telephone line system according to the embodiment of the present invention.

FIG. 4 is a block diagram of a conventional communication system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 line connection device 3 wireless device 5 portable wireless device 11 telephone 13 extension 15 transmission signal line 16 reception signal line 23 CPU 24 VOX circuit 41 line connection device 52 2W / 4W conversion circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI H04Q 7/30 (56) References JP-A-63-158945 (JP, A) JP-A-1-130655 (JP, A) Japanese Unexamined Patent Publication No. Hei 4-156098 (JP, A) Japanese Unexamined Patent Publication No. Hei 6-188833 (JP, A) Japanese Unexamined Patent Publication No. Sho 63-236427 (JP, A) Japanese Unexamined Patent Publication No. Sho 63-299417 (JP, A) JP, A) JP-A-62-2727 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04M 11/00-11/10 H04M 1/00 H04Q 7/00-7 / 38 H04B 7/26

Claims (2)

(57) [Claims] 1. A two-wire / four-wire conversion circuit for interconnecting a transmission signal line and a reception signal line connected to a half-duplex or simplex wireless device and a two-wire telephone line, A transmission control signal generation circuit for detecting a transmission signal sent from the two-wire telephone line to the transmission signal line and generating a transmission control signal for controlling the wireless device to be in a transmission state upon detection. in line connection device which are, when outputting the transmission control signal to the wireless device, with sending the first predetermined sound signals to the reception signal line, before
When the output of the transmission control signal to the wireless device is stopped,
The first predetermined sound signal is at least a part of a frequency component
Outputs a second predetermined sound signal to the reception signal line.
Line connection device, characterized in that it comprises a signal output circuit that. 2. The signal output circuit according to claim 1, wherein a predetermined control signal is sent from said two-wire telephone line side.
And line connection according to claim 1, wherein the stop at least any one of the outputs of the second predetermined sound signal.