JPH114298A - Loud voice talking system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a loud voice talking system which has a simplified constitution of a central processing part where the loud voice talking is mediated between the talking terminals. SOLUTION: Plural talking terminals 1a are connected to a central processing part 2 via two transmission lines 3a. A central transmission processing part 21 applies the time division multiplexing to a digital talking signal and a control signal and transmits these signals to a transmission processing part 14 of every terminal 1a by a so-called 'ping-pong' transmission system. A digital signal processing part 22 transfers the digital talking signal to every terminal 1a via the part 21. When the loud voice talking is performed with the terminals 1a, a loud voice talking processing part 25 of the part 22 processes the digital talking signals received from toe terminals 1a to prevent the oscillation due to the detouring of voices.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker system for making a loudspeaker call between call terminals at home.

[0002]

2. Description of the Related Art In this kind of loudspeaker communication system, a plurality of communication terminals are connected to a central processing unit via a transmission line, and communication signals are transmitted between each of the communication terminals and the central processing unit. A central processing unit includes a network control unit for controlling connection between a plurality of call terminals connected via a transmission line, and a network control unit. And a signal processing unit for processing a speech signal input through the telephone and performing a loudspeaking call between the speech terminals.
No. 32493).

[0003]

In the loudspeaker system having the above-mentioned structure, a network control unit for controlling connection between a plurality of communicator terminals is required to perform loudspeaker communication between the call terminals. However, there is a problem that the wiring configuration between the network control unit and the signal processing unit becomes complicated depending on the number of call terminals performing the communication. There is also a problem that it is necessary to change the network control unit according to the number of call terminals connected to the central processing unit.

[0004] Further, when making a voice call between the call terminals, it is necessary to prevent howling due to the wraparound of the sound between the speaker and the microphone provided in each of the call terminals. Since the loudspeaker call processing for suppressing the voice wraparound was performed, there was a problem that the configuration of the call terminal became complicated. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to simplify the wiring between each call terminal and the central processing unit, and to simplify the configuration of the call terminal. To provide a call system.

[0005]

According to the first aspect of the present invention, there is provided a transmission processing unit comprising a speaker and a first microphone, for transmitting and receiving a digital call signal and a control signal to and from the outside. And converting the digital communication signal input from the transmission processing unit into an analog communication signal and outputting the analog communication signal to the speaker, and converting the analog communication signal input from the first microphone into a digital communication signal and transmitting the converted signal to the transmission processing unit. A plurality of call terminals provided with a codec unit for outputting,
A central transmission processing unit that transmits and receives a digital communication signal and a control signal to and from the transmission processing unit, a digital signal processing unit that includes a serial input / output port and performs signal processing on the digital communication signal input through the central transmission processing unit; And a central processing unit comprising a central control unit for controlling the operation of each unit. The plurality of call terminals and the central processing unit are connected via two transmission lines, respectively, and the transmission processing unit and the central transmission processing The digital communication signal and the control signal are multiplexed between the communication units, and the signals are transmitted by a ping-pong transmission method in which the transmission direction of the transmission line is switched at predetermined time intervals. The digital call signal and the control signal are separated by time division multiplexing for each signal, and each signal is transmitted between the digital signal processing unit and the central control unit via the serial input / output port. Output, and at the time of performing a loudspeaker call between the call terminals via the central processing unit, the digital call processing unit performs a loudspeaker call process for suppressing the wraparound of sound from the speaker of each of the call terminals to the first microphone. Therefore, there is no need to provide a network control unit in the central processing unit, and wiring in the central processing unit can be simplified. In the central processing unit, the digital call signal input from the call terminal via the central transmission unit is subjected to voice call processing, and is transmitted again to another call terminal via the central transmission unit. There is no need to perform call processing, and the configuration of the call terminal can be simplified.

According to a second aspect of the present invention, in the first aspect of the present invention, when a loudspeaker call is performed between the respective call terminals via the central processing unit, the voice call control signals are input from the respective call terminals in accordance with the respective volume control signals. Since the digital signal processing unit has a volume setting unit that sets the volume level of the digital call signal output to each call terminal, it is necessary to provide a circuit such as an amplifier for adjusting the speaker volume in each call terminal. And the size and cost of the communication terminal can be reduced.

According to a third aspect of the present invention, in the first or second aspect of the present invention, when a loudspeaker call is performed between the respective call terminals through the central processing unit, the speaker of the call terminal on the other party's side communicates with the own call terminal. The digital signal processing unit is provided with an oscillation detection unit for detecting the wraparound of the sound to the first microphone and the wraparound of the voice from the speaker of the own talk terminal to the first microphone of the talk terminal of the other party. Since the digital signal processing unit reduces the volume level of the digital call signal output to each call terminal according to the detection result of the oscillation detection unit, even when the call terminals are arranged close to each other,
When making a loudspeaker call between any call terminals, it is possible to suppress the sneak of voice from another call terminal and prevent oscillation due to the sneak of voice.

According to a fourth aspect of the present invention, in the first to third aspects of the present invention, when a loudspeaker call is made between three or more call terminals via the central processing unit, an input is made from the first microphone of each call terminal. Since the digital signal processing unit is provided with a communication level output / combining unit for synthesizing each digital communication signal so that the volume level of the obtained digital communication signal becomes substantially the same and outputting the signal to the corresponding communication terminal, three or more When making a loudspeaker call between the call terminals, the voices input from the respective call terminals can be balanced.

According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the digital signal processing section includes an output combining section for superimposing a signal corresponding to the control signal input from the central control section on the digital communication signal and outputting the signal. It is possible to respond to the call of the intercom or to receive the announcement signal even during a loudspeaker call by superimposing the call from the intercom or the notification signal of various sensors on the voice input from each call terminal and outputting it. be able to.

According to a sixth aspect of the present invention, in the first to fifth aspects of the present invention, an analog signal from the telephone terminal is converted into a digital signal on a transmission line connecting the central processing unit and the telephone terminal, and the central processing unit is connected to the central processing unit. Since an adapter that performs transmission by the ping-pong transmission method is interposed between the conventional communication terminals, the conventional communication terminal that inputs and outputs analog signals by using the adapter can be used similarly to the communication terminal that inputs and outputs digital signals. it can.

According to a seventh aspect of the present invention, in the first to sixth aspects, the central processing unit is provided with an external line adapter for communicating with an external terminal via an ISDN line, and the digital signal processing unit is connected to the external line adapter. Since external line processing is performed in accordance with the control signal input through the telephone line and each of the call terminals responds to the external line call, the call terminal for the loudspeaker call can respond to the call from the external line.

According to an eighth aspect of the present invention, in the invention of the seventh aspect, a modular jack for connecting either a door phone or an ISDN line to the telephone terminal, and either a door phone or an ISDN line is connected to the modular jack. A switch is provided to switch between a codec and a digital communication signal between the central processing unit and a control signal, or whether the signal is output as it is, according to the switching state of the changeover switch. It can be switched and used for doorphone or ISDN line connection.

According to the ninth aspect of the present invention, in the first to eighth aspects, the transmission processing unit and the central transmission processing unit
A signal obtained by multiplexing a plurality of digital communication signals and one control signal is transmitted by a ping-pong transmission method, and one of the plurality of digital communication signals is used for communication with either a door phone or an outside line, and another digital communication signal is used. Since the call signal is used for communication with a call terminal installed indoors, even if there is a call from a door phone or an outside line during a call between the call terminals, the digital call signal is switched to enable the call Can respond to a call from a door phone or an outside line.

According to a tenth aspect of the present invention, in the first to eighth aspects, a video display unit for displaying an image on the telephone terminal and a second microphone for preventing howling are provided, and a transmission processing unit and a central transmission processing unit are provided. Between two digital call signals and one
A signal multiplexed with the control signals is transmitted by the ping-pong transmission method and transmitted from the central processing unit to the call terminal.
One of the digital call signals is used for a video signal,
Two digital call signals transmitted from the call terminal to the central processing unit are used for signals input from the first and second microphones, and the digital signal processing unit uses the signals input from the first and second microphones , The loudspeaker call processing for suppressing the wraparound of sound from the speaker to the first microphone is performed, so that the central processing unit can perform the loudspeaker call processing.

According to an eleventh aspect of the present invention, in the first to ninth aspects of the present invention, the communication terminal includes an outdoor installation communication terminal including a camera and a modulator for modulating an analog video signal captured by the camera. A communication terminal for indoor installation comprising a demodulation unit for demodulating the modulated video signal modulated by the unit and a video display unit for displaying an analog video signal demodulated by the demodulation unit; both the communication terminals and the central processing unit; Since the digital call signal, the control signal, and the modulated video signal are multiplexed and transmitted by the ping-pong transmission method, the digital call signal and the modulated video signal are transmitted and received between the call terminals through the central processing unit. It is possible to monitor the image captured by the camera while making a voice call between the call terminals.

In the twelfth aspect of the present invention, the first to eleventh aspects are provided.
In the invention, the digital communication signal transmitted between the transmission processing unit and the central transmission processing unit is compressed and transmitted at a low bit rate, so that the noise component included in the digital communication signal is compressed and expanded. Thereby, the noise component can be reduced.

[0017]

Embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a schematic configuration diagram showing a loudspeaker system according to this embodiment. 1a, 1b, 1c are call terminals,
Reference numeral 2 denotes a central processing unit, and a plurality of communication terminals 1a are connected to the central processing unit 2 via two transmission lines 3a, 3b, 3c.

The call terminal 1a includes a speaker 11a and a first
And a codec unit 13 that converts a digital call signal to the speaker 11a transmitted from the central processing unit 2 into an analog call signal and converts an analog call signal input from the microphone 12a into a digital call signal. , A transmission processing unit 14 for transmitting and receiving a digital call signal and a control signal to and from the central processing unit 12, a CPU 15 for controlling the operation of each unit, and an operating power supply to each unit while being supplied with power via the transmission line 3a. Power receiving unit 1 to be supplied
And 6. The communication terminals 1b, 1c,... Have the same configuration as the communication terminal 1a.

The central processing unit 2 includes a central transmission processing unit 21 for exchanging digital communication signals and control signals with a plurality of communication terminals 1a, a digital signal processing unit 22 having a serial input / output port, and various units. And a timing generator 24 for generating various timings required for time division multiplex transmission.

Here, between the central transmission processing unit 21 and the digital signal processing unit 22, a time-division multiplexed signal 4a as shown in FIG. ) And digital communication signals (microphone signals) from each of the communication terminals 1a. Further, between the central transmission processing unit 21 and the CPU 23, a control signal is exchanged with each of the communication terminals 1a using a time division multiplexed signal 4b as shown in FIG.

The multiplexed digital call signal shown in FIG. 4 is transmitted between the transmission processing unit 14 of the call terminal 1a and the central transmission processing unit 21 of the central processing unit 2 via two transmission lines 3a. (Speaker signal and microphone signal) and a control signal are transmitted and received by a so-called ping-pong transmission method. Note that the ping-pong transmission method means that the transmission direction of a signal on a transmission line [for example, uplink (call terminal 1a → central control unit 2) / downlink (central processing unit 2 → call terminal 1a)] is several μsec to several m.
It refers to a transmission system that switches signals every Sec and transmits signals. .. Also perform signal transmission with the central processing unit 2 by the ping-pong transmission method in the same manner as the communication terminal 1a.

As described above, the central processing unit 2 controls each call terminal 1
a digital communication signal and a control signal are transmitted and received to and from the communication terminal a. A digital signal processing unit 22 processes a digital communication signal input from a certain communication terminal via a central transmission processing unit 21 to perform central processing. By outputting to another call terminal via the processing unit 12, the call terminal can make a voice call with another call terminal via the central processing unit 2.

As shown in FIG. 5, the loudspeaker communication processing unit 25 provided in the digital signal processing unit 22 is, for example, an LMS.
(Least Mean Square) algorithm using digital filters 25a and 25b.
In addition to suppressing the sound sneaking into 2a and suppressing the sound sneaking from the speaker 11b of the telephone terminal 1b to the microphone 12b by the digital filter 25b, the generation of the oscillation and the echo due to the sneak of the voice is prevented (loud voice communication processing). .

For example, when a loudspeaker call is made between the call terminals 1a and 1b via the central processing unit 2, the loudspeaker call processor 25 of the digital signal processor 22 is connected to the microphone 1 of the call terminal 1a.
2a to process the voice signal input from the
b of the call terminal 1b.
2b to process the voice signal input from the
By outputting the signal to the speaker 11a, the network control unit provided in the conventional central processing unit 2 becomes unnecessary.
The wiring in the central processing unit 2 is simplified.

Here, between the transmission processing unit 14 and the central transmission processing unit 21, the digital communication signal and the control signal, which are digital signals, are time-division multiplexed and signal transmission is performed by the ping-pong transmission method. A pair of transmission lines 3a can transmit both a digital call signal and a control signal, and a hybrid circuit (two-wire / four-wire conversion circuit) provided in each call terminal 1a in the conventional voice communication system.
Becomes unnecessary. Furthermore, since digital signals are used for signal transmission between the communication terminals 1a and the central processing unit 2, noise resistance is improved.

In addition, in the central processing unit 2, since signals are transmitted and received by the time division multiplexed signal between the central transmission processing unit 21 and the digital signal processing unit 22, they are physically paired, but logically. Can secure a plurality of transmission lines, and digital call signals from all the call terminals 1a... Can be taken into the digital signal processing unit 22 at the same time.

As shown in FIG. 6, a low-loss voice switch 25c may be provided between the digital filters 25a and 25b of the voice call processor 25.
Compares the volume level of the digital call signal input from the call terminal 1a with the volume level of the digital call signal input from the call terminal 1b. Assuming that the smaller communication terminal is currently listening, the digital communication signal of the smaller volume level is attenuated to prevent howling and reduce the signal processing amount of the loudspeaker communication processor 25. Can be done.

In the present embodiment, the LMS is used as the algorithm of the digital filter. However, the algorithm is not limited to the LMS, and a method other than the LMS, such as the RLMS method or the steepest descent method, may be used. Needless to say. (Embodiment 2) FIG. 7 is a schematic configuration diagram showing a voice call system of this embodiment.

In the loudspeaker communication system of the present embodiment, in the loudspeaker communication system of the first embodiment, based on a volume control signal transmitted from each of the telephone terminals 1a. Volume setting unit 2 for setting the volume level of the sound output from speakers 11a.
6 are provided. Since the configuration other than the volume setting unit 26 is the same as that of the loudspeaker system of the first embodiment, the same components are denoted by the same reference numerals and description thereof will be omitted.

The volume setting unit 26 controls each of the communication terminals 1a... Based on the volume control signal transmitted from each of the communication terminals 1a.
, Respectively, is provided with a circuit such as an amplifier for adjusting the volume of the sound output from the speaker 11a... In each call terminal 1a. No need,
The circuit configuration of each call terminal 1a can be simplified,
.. Can be reduced in size and cost.

(Embodiment 3) FIG. 8 is a schematic configuration diagram showing a loudspeaker system according to this embodiment. In this embodiment,
In the voice call system according to the second embodiment, each call terminal 1
When a, 1b, and 1c are arranged close to each other, an oscillation for detecting an oscillation phenomenon in which a sound output from a speaker of one communication terminal 1a... The detection unit 27 is provided in the digital signal processing unit 22. Since the configuration other than the oscillation detection unit 27 is the same as that of the loudspeaker system of the first or second embodiment, the same components are denoted by the same reference numerals and description thereof will be omitted.

For example, as shown in FIG. 9, when a voice call is made between the call terminals 1a and 1b disposed close to each other, the sound output from the speaker 11a of the call terminal 1a is transmitted to the microphone 12b of the call terminal 1b. Or call terminal 1b
When the sound output from the speaker 11b of the communication terminal 1a wraps around to the microphone 12a of the telephone terminal 1a, and an oscillating phenomenon occurs due to the sneaking of the sound, the oscillation detecting unit 27 detects the oscillating phenomenon and sets the volume setting units 26a, 26b. Is used to lower the volume level of the speakers 11a and 11b of the communication terminals 1a and 1b, thereby suppressing oscillation due to wraparound of voice and realizing a loudspeaker call without howling between the communication terminals 1a.

(Embodiment 4) FIG. 10 is a schematic configuration diagram showing a loudspeaker system according to this embodiment. In the present embodiment, in the loudspeaker systems of the first to third embodiments, a call level adjustment for adjusting the volume level of the voice (ie, the digital call signal) output from the speakers of the respective call terminals 1a, 1b, 1c. The synthesizing unit 28 is provided in the digital signal processing unit 22. Since the configuration other than the communication level adjusting / combining unit 28 is the same as that of the loudspeaker communication systems of the first to third embodiments, the same components are denoted by the same reference numerals and description thereof will be omitted.

The central processing unit 2 has two transmission lines 3
When a call is made between the three call terminals 1a, 1b, and 1c respectively connected through the communication terminals a, 3b, and 3c, the call level adjustment / combination unit 28 The volume levels of the microphone signals of the terminals 1a, 1b, 1c are compared to match the volume levels of the microphone signals. For example, as shown in FIG. 11, the call level adjusting / combining unit 28 sends a signal obtained by multiplying the microphone signal of the call terminal 1b by 0.5 to the speaker 11 of the call terminal 1a,
c, and outputs the sum of the microphone signals of the call terminals 1c and 1a to the speaker of the call terminal 1b.
By outputting the sum of the microphone signal of the communication terminal 1a and the signal obtained by multiplying the microphone signal of the communication terminal 1c by 0.5 to the speaker of the communication terminal 1c, the three communication terminals 1a and 1 are output.
It is possible to carry out a loudspeaker call with a matched volume level between b and 1c.

In this embodiment, the call level adjusting / combining unit 28 performs a loudspeaker call between the three call terminals 1a, 1b, 1c, but the number of the call terminals 1a, 1b, 1c is three.
This is not intended to limit the number of call terminals to four or more.
It is also possible to make a voice call between a. (Embodiment 5) FIG. 12 is a schematic configuration diagram showing a voice communication system of the present embodiment.

In the present embodiment, in the loudspeaker system of the fourth embodiment, an output synthesizing unit 29 for synthesizing a signal corresponding to a control signal input from the CPU 23 and a digital telephone signal is provided in the digital signal processing unit 22. . Since the configuration other than the output synthesizing unit 29 is the same as that of the loudspeaker communication systems of the first to fourth embodiments, the same components are denoted by the same reference numerals and description thereof will be omitted.

For example, when the call terminals 1a and 1b are making a voice call via the central processing unit 2 (at the time of an extension call),
The digital signal processing unit 22 processes the digital call signal (microphone signal) input from the call terminal 1b and outputs it as a speaker signal to the call terminal 1a, and also outputs the digital call signal (microphone signal) input from the call terminal 1a. ) Is output as a speaker signal to the communication terminal 1b.

When a call is made from the outdoor-installed telephone terminal 1c, which is a door phone installed outdoors, during this extension call, as shown in FIG.
The intercom call signal from the call terminal 1c is superimposed on the digital call signal (microphone signal) input from the call terminal 1b, and output as a speaker signal to the call terminal 1a via the central transmission processing unit 21. The call terminal 1c receives the input digital call signal (microphone signal).
Superimposed on the intercom call signal from the
By outputting a speaker signal to the communication terminal 1b via the communication terminal 1b, the communication terminals 1a and 1b can respond to a call from another communication terminal 1c even during a loudspeaker call.

As shown in FIG. 14, the central processing unit 2
Are provided with various sensors (for example, a fire alarm, a gas leak detector, etc.) 7, an alarm signal of the sensor 7 is input to the CPU 23, and the output synthesizing unit 29 outputs the digital signal input from the microphone of the communication terminal 1 a. C for the call signal (microphone signal)
A control signal from the PU 23, that is, a notification signal from the sensor 7 may be superimposed and output as a speaker signal to another call terminal.

For example, if the sensor 7 detects a fire and issues a notification signal (fire alarm) while the call terminals 1a and 1b are making a voice call via the central processing unit 2, FIG.
As shown in FIG. 5, the output synthesizing unit 29 superimposes the notification signal of the sensor 7 on the digital communication signal (microphone signal) input from the communication terminal 1b, and outputs the speaker signal to the communication terminal 1a via the central transmission processing unit 21. And a notification signal of the sensor 7 is superimposed on a digital communication signal (microphone signal) input from the communication terminal 1a, and output as a speaker signal to the communication terminal 1b via the central transmission processing unit 21. The terminals 1a and 1b can receive a notification signal from the sensor 7 even during a loud-voice call.

(Embodiment 6) FIG. 16 is a schematic configuration diagram showing a loudspeaker system according to this embodiment. In the present embodiment, in the loudspeaker system of the fourth embodiment, a call terminal 1d comprising a door phone for inputting / outputting an analog signal and a door phone adapter 4 serving as an adapter for connecting the call terminal 1d to the transmission line 3c are provided. In addition, the call terminal 1d
Configurations other than the doorphone adapter 4 are the same as those of the first to fourth embodiments.
, The same components are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 17, the intercom adapter 4 is a ping-pong LSI 4 for performing signal transmission with the central transmission processing unit 21 via the transmission line 3c by the ping-pong transmission method.
3, a codec section 42 for converting a digital call signal input from the ping-pong LSI 43 into an analog call signal, and converting an analog call signal input from the call terminal 1d into a digital call signal, a codec section 42 and the call terminal 1d. And a two-wire / four-wire conversion circuit (hybrid circuit) 41 connecting between the two. The two-wire / four-wire conversion circuit includes a transformer and an electronic circuit. The two-wire side transmits and receives both the transmission signal and the reception signal, and the four-wire side uses two of the four wires for transmission. Are used for reception.

The intercom adapter 4 converts the analog call signal input from the call terminal 1d into another call terminal 1a,
1b, the signal is adjusted to the volume level of the digital communication signal, and then time-division multiplexed and transmitted to the central transmission processing unit 21 by the ping-pong transmission method. A voice call can be made in the same manner as the other call terminals 1a.

(Embodiment 7) FIG. 18 is a schematic configuration diagram showing a loudspeaker system according to this embodiment. In the present embodiment, in the loudspeaker system of the fourth embodiment, an external line adapter 5 for performing communication processing with an ISDN line 6 provided by Nippon Telegraph and Telephone Corporation (NTT) is connected to a central transmission processing unit 2.
1 and the call terminals 1b,
The digital signal processing unit 22 includes an external line communication processing unit 30 that performs communication processing between the ISDN line 6 and 1c.
Since the configuration other than the external line adapter 5 and the external line communication processing unit 30 is the same as that of the loudspeaker communication systems of the first to fourth embodiments, the same components are denoted by the same reference numerals and description thereof is omitted.

Here, when a call signal from the ISDN line 6 is input to the digital signal processing unit 22 via the external line adapter 5 and the central transmission processing unit 21, the external line communication processing unit 30 of the digital signal processing unit 22 The call signal input from the line 6 is signal-processed to each call terminal 1b,
1c, and a call process is performed between the ISDN line 6 and the call terminal whose answer switch (not shown) is depressed, so that each call terminal 1 receives an incoming call from the ISDN line 6.
b ...

By the way, as a call terminal used in the voice call system of this embodiment, as shown in FIG.
A telephone terminal in which a modular jack 18 to which either an ISDN line or a loudspeaker interphone is connected and a switch SW for selecting whether to connect an ISDN line or a loudspeaker interphone to the modular jack 18 are arranged on the front of the case. 1e.

In the call terminal 1e, as shown in FIG.
When the changeover switch SW is set to the position indicated by the solid line in FIG.
Side), the digital call signal input from the central processing unit 2 or the ISDN line 6 is output as it is,
The changeover switch SW is set to the position (HF
Side), the codec unit 13 converts the analog call signal input from the loudspeaker interphone (not shown) into a digital call signal, and then converts the ping-pong transmission LSI 1
4 'time-division multiplexes this digital call signal and transmits it to the central transmission processing unit 21 by the ping-pong transmission method.

Here, as shown in FIG. 21, when the changeover switch SW is set on the ISDN line (TEL) side, the DSU 41 or the ISDN corresponding terminal 42 corresponding to the ISDN line is directly connected to the telephone terminal 1e. By doing
External calls can be made anywhere as long as the call terminal 1e is installed. Also, a changeover switch SW
Is set to the loudspeaker interphone (HF) side, the loudspeaker interphone 43 can be used as a home telephone terminal by connecting the loudspeaker interphone 43 consisting of only a speaker and a microphone to the telephone terminal 1e.

(Embodiment 8) In the loudspeaker systems of the first to seventh embodiments, as shown in FIG. 22, for example, one control signal and two digital Signal transmission is performed by a ping-pong transmission method using a signal multiplexed with a call signal. FIG. 2 is a schematic configuration diagram of a call terminal 1 used in the voice call system of the present embodiment.
3 is shown. In the present embodiment, as shown in FIG. 24, one of the two digital communication signals (communication paths) transmitted between the communication terminal 1 and the central processing unit 2 is used as a signal for the intercom communication terminal, The other is used as the signal of the extension telephone terminal. Here, when the call terminal 1 receives a call from the door phone during an extension call with another extension call terminal,
By using the switching means 35 to put the call path on the extension call terminal side into a hold state and switching the call path to the door phone call terminal side, it is possible to perform a call with the door phone call terminal, so-called call waiting. Can be performed.

The configuration other than the communication terminal 1 is the same as that of the first embodiment.
The description is omitted because it is the same as that of the loudspeaker communication systems of Nos. 1 to 7. In addition, common components are denoted by the same reference numerals, and description thereof is omitted. (Embodiment 9) FIG. 25A shows an external view of a telephone terminal 1f which is a telephone terminal for outdoor installation, and FIG. 25B shows a schematic configuration diagram thereof. FIG. 26 is an external view of a call terminal 1g serving as a call terminal.
26A shows a schematic configuration diagram, and FIGS. 27A and 27B show signals transmitted by the ping-pong transmission method between the call terminals 1f and 1g and the central transmission processing unit 21. Show. The configuration other than the call terminals 1f and 1g is the same as that of the first embodiment.
Since it is the same as that of the loudspeaker communication systems of Nos. 1 to 8, description thereof is omitted. In addition, common components are denoted by the same reference numerals, and description thereof is omitted.

The telephone terminal 1f receives the camera 18 for capturing the surrounding image, the video compression unit 19 for compressing the image captured by the camera 18, and the image compressed by the video compression unit 19 by the microphone 12. Ping-pong transmission LSI 1 that transmits to central transmission processing unit 21 together with voice
4 ', and is arranged at the entrance or the like. The signal transmitted from the central transmission processing unit 21 to the communication terminal 1f is composed of one control signal and two digital communication signals,
One of the two digital call signals is the call data input by the microphone 12, and the other is the compressed video signal compressed by the video compression unit 19.

On the other hand, the call terminal 1g receives the ping-pong transmission LS
A video decompression unit 31 for decompressing the compressed video signal input from I14 ', a monitor 20 for displaying a digital video signal decompressed by the video decompression unit 31, and a microphone 12a as a first microphone for inputting audio. And a microphone 34 as a second microphone for preventing howling, which is disposed indoors. Call terminal 1g and central transmission processing unit 21
The signal used for signal transmission between the two is composed of one control signal and two digital communication signals, as shown in FIG.
As shown in (1), the signal transmitted from the central transmission processing unit 21 to the communication terminal 1g is such that one of the two digital communication signals is communication data (digital communication signal) input by the microphone 12, and One is a compressed video signal compressed by the video compression unit 19.

Therefore, by using the call terminals 1f and 1g to image the visitor at the entrance with the camera 18 of the call terminal 1f and displaying the image picked up by the camera 18 on the monitor 20 of the call terminal 1g, the monitor At 20, the user can make a voice call while watching the image of the visitor at the entrance. As shown in FIG. 27 (b), the signal transmitted from the call terminal 1g to the central transmission processing unit 21 is one of the two digital call signals, which is a call data (digital) input from the microphone 12a. The communication data and the reference microphone data input from both microphones 12a and 34 are transmitted to the central processing unit 2 while the other one is used as the reference microphone data input from the microphone 34, and the digital signal processing unit 22 By performing signal processing on the difference between the two data, it is possible to prevent howling and eliminate the need to provide a signal processing unit for suppressing howling in the call terminal 1g, thereby reducing the size and cost of the call terminal 1g. Can be.

By the way, as shown in FIGS. 28A and 28B, instead of providing the video compression unit 19 in the communication terminal 1f,
'And the video modulating unit 19' image modulating unit 19 for modulating the image captured by the camera 18 pass filter 32 to a modulated video signal modulated by the frequency f ₂ or more
and a, and a low-pass filter 33a to the frequency f ₁ or less an audio signal and a control signal provided, as shown in FIG. 29 (a) (b), instead providing the image decompression unit 31 to the call terminal 1g, transmission line frequency f ₂ or more frequency components of the transmitted signal 3 via the central processing unit 21, i.e.,
A high-pass filter 32b for passing the modulated video signal;
A video demodulation unit 31 ′ for demodulating a modulated video signal input via the high-pass filter 32 b, and a frequency component lower than the frequency f _{1 of the} signal transmitted from the central processing unit 21 via the transmission line 3, that is, audio A low-pass filter 33b for passing the signal and the control signal may be provided.
As shown in FIG. 0, by separating the frequency bands of the video signal, the audio signal, and the control signal and transmitting the signal, the video signal is transmitted together with the call data between the call terminals 1f and 1g and the central processing unit 2. And make a voice call while looking at the visitor's face. At this time, since the modulated video signal is transmitted as an analog signal, a moving image can be transmitted regardless of the bit rate of the transmission line 3.

(Embodiment 10) By the way, a call signal (voice signal and control signal) is transmitted between the call terminal 1 and the central processing unit 2 by, for example, CELP (Code Excited Linear Predictor).
on) or the like, and may be transmitted by compressing the audio signal without processing [FIG.
Compared to (a)], by compressing / expanding the noise component in the unprocessed state, as shown in FIG.
There is an effect that a noise component can be reduced. In addition, since the number of bits can be reduced as compared with a normal PCM (Pulse Code Modulation) coding method, transmission can be performed at a low bit rate. As shown in FIG.
Digital communication signal (voice signal) and control signal are transmitted through transmission line 3.
Occupies a lower frequency band, and converts the digital communication signal (voice signal) and the control signal to the frequency f ₃ (f ₃ <f ₁ ).
It can be: Therefore, the above-described high-pass filters 32a and 32b and low-pass filter 3
A low-order filter (a filter that is not abrupt) can be used for 3a and 33b, so that the filter can be reduced in size and cost can be reduced.

[0056]

As described above, according to the first aspect of the present invention, there is provided a transmission processing unit which includes a speaker and a first microphone, and transmits and receives digital communication signals and control signals to and from an external device. A codec unit is provided for converting the input digital call signal into an analog call signal and outputting the analog call signal to a speaker, and converting the analog call signal input from the first microphone into a digital call signal and outputting the digital call signal to a transmission processing unit. A plurality of communication terminals, a central transmission processing unit for transmitting and receiving a digital communication signal and a control signal between the transmission processing unit, and a serial input / output port for transmitting a digital communication signal input through the central transmission processing unit. A plurality of call terminals and a central processing unit, each of which includes a digital signal processing unit for processing and a central processing unit including a central control unit for controlling the operation of each unit. Are connected via a transmission line, and between the transmission processing unit and the central transmission processing unit, a digital call signal and a control signal are multiplexed, and the transmission direction of the transmission line is switched at predetermined intervals by a ping-pong transmission method. The signal is transmitted, and the central transmission processing unit separates the digital communication signal and the control signal transmitted from each communication terminal, time-division multiplexes each signal, and outputs the digital signal processing unit and the central signal via the serial input / output port. When inputting / outputting each signal to / from the control unit and performing a loudspeaking call between the call terminals via the central processing unit, the digital call processing unit transmits the voice from the speaker of each call terminal to the first microphone. Since the loudspeaker call processing for suppressing the wraparound is performed, there is no need to provide a network control unit in the central processing unit, and the wiring in the central processing unit can be simplified. In addition, since digital signals are used for signal transmission between the central processing unit and each communication terminal, there is an effect that noise resistance can be improved. Further, the central processing unit processes the digital call signal input from the call terminal via the central transmission unit through a loudspeaker call, and transmits the signal again to another call terminal via the central transmission unit. There is also an effect that it is not necessary to perform a call process, the configuration of the call terminal can be simplified, and the cost of the entire voice call system can be reduced.

According to a second aspect of the present invention, when a loudspeaker call is made between the respective call terminals via the central processing unit, a digital signal output to each of the call terminals according to a volume control signal input from each of the call terminals. Since the digital signal processing unit is provided with a volume setting unit for setting the volume level of the call signal, it is not necessary to provide a circuit such as an amplifier for adjusting the volume of the speaker in each call terminal. And cost reduction can be achieved.

According to a third aspect of the present invention, when a loudspeaker call is made between the respective call terminals via the central processing unit, a voice from the speaker of the call terminal of the other party to the first microphone of the own call terminal is transmitted. The digital signal processing unit is provided with an oscillation detection unit for detecting an oscillation due to a wraparound or an oscillating voice from the speaker of the own communication terminal to the first microphone of the communication terminal of the other party. Since the volume level of the digital call signal output to each call terminal is reduced according to the detection result, even when the call terminals are arranged close to each other, when making a voice call between any call terminals In addition, we suppress sound wraparound from other call terminals,
Oscillation due to voice wraparound can be prevented, and there is an effect that a loudspeaker call can be performed at an appropriate volume.

According to a fourth aspect of the present invention, when a voice call is made between three or more call terminals via the central processing unit, the volume level of the digital call signal input from the first microphone of each call terminal is changed. Since the digital signal processing unit is provided with a communication level output / synthesis unit for synthesizing each digital communication signal so as to be substantially the same and outputting the combined signal to the corresponding communication terminal, a voice communication is performed between three or more communication terminals. In this case, there is an effect that a call with a balanced voice input from each call terminal can be performed.

According to a fifth aspect of the present invention, since the digital signal processing section is provided with an output synthesizing section for superimposing a signal corresponding to the control signal input from the central control section on the digital communication signal and outputting the signal, By superimposing a call from a door phone or a notification signal from various sensors on the voice input from the terminal and outputting it, there is an effect that it is possible to respond to the call of the door phone and receive the notification signal even during a loudspeaking call.

According to a sixth aspect of the present invention, an analog signal from the telephone terminal is converted into a digital signal and transmitted to the central processing unit by a ping-pong transmission method on a transmission line connecting the central processing unit and the telephone terminal. Since the adapter for performing the operation is interposed, the conventional communication terminal that inputs and outputs analog signals by using the adapter can be used similarly to the communication terminal that inputs and outputs digital signals.

According to a seventh aspect of the present invention, the central processing unit includes an ISD
An external line adapter for communicating with an external terminal through the N line is provided, a digital signal processing unit performs external line processing according to a control signal input through the external line adapter, and each telephone terminal responds to an external line call. Therefore, it is possible to respond to a call from an outside line using a telephone terminal for a loudspeaker call, and to respond to a call to an outside line from any place where the telephone terminal is installed.

According to the present invention, a telephone terminal is provided with a modular jack for connecting either a door phone or an ISDN line, and a changeover switch for switching between the door phone and an ISDN line to the modular jack. , According to the switching state of the changeover switch,
Since the switching between the codec of the digital call signal and the control signal to and from the central processing unit or the output as it is is switched, there is an effect that the call terminal can be switched and used for the connection of the door phone or the ISDN line.

According to a ninth aspect of the present invention, a signal obtained by multiplexing a plurality of digital communication signals and one control signal is transmitted between a transmission processing unit and a central transmission processing unit by a ping-pong transmission method. One of the digital call signals is used for a call with either a door phone or an outside line, and the other digital call signal is used for a call with a call terminal installed indoors. Even if there is a call from a door phone or an outside line, by switching the digital call signal, there is an effect that a call terminal during a loudspeaker call can respond to a call from the door phone or an outside line.

According to a tenth aspect of the present invention, a video display unit for displaying an image on a telephone terminal and a second microphone for preventing howling are provided, and two digital telephone calls are made between the transmission processing unit and the central transmission processing unit. A signal obtained by multiplexing a signal and one control signal is transmitted by a ping-pong transmission method, and one of two digital communication signals transmitted from the central processing unit to the communication terminal is used for a video signal, and the communication is performed. The two digital call signals transmitted from the terminal to the central processing unit are used for signals input from the first and second microphones, and the digital signal processing unit converts the signals input from the first and second microphones into signals. And the central processing unit performs the loudspeaker call processing, so that the loudspeaker call processing that performs the loudspeaker call processing for each call terminal is performed. Provide a part No necessity, a simplified configuration of a call terminal, there is an effect that it is possible to reduce the cost.

According to an eleventh aspect of the present invention, the communication terminal includes an outdoor installation communication terminal including a camera and a modulator for modulating an analog video signal captured by the camera, and a modulation video signal modulated by the modulator. It comprises a demodulation unit for demodulation and a call terminal for indoor installation having a video display unit for displaying an analog video signal demodulated by the demodulation unit. Digital call signals and control are performed between both call terminals and the central processing unit. Since the signal and the modulated video signal are multiplexed and transmitted by the ping-pong transmission method, a digital call signal and a modulated video signal are transmitted and received between the call terminals through the central processing unit, so that a voice call can be performed between the call terminals. However, there is an effect that the image captured by the camera can be monitored.

According to a twelfth aspect of the present invention, since the digital communication signal transmitted between the transmission processing unit and the central transmission processing unit is compressed and transmitted at a low bit rate, the noise component included in the digital communication signal is reduced. Has the effect of reducing the noise component.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a loudspeaker system according to a first embodiment.

FIG. 2 is an explanatory diagram illustrating signals transmitted and received between a central transmission processing unit and a digital signal processing unit according to the first embodiment.

FIG. 3 is an explanatory diagram illustrating signals transmitted and received between a central transmission processing unit and a CPU according to the embodiment.

FIG. 4 is an explanatory diagram illustrating signals transmitted and received between the central transmission processing unit and the transmission processing unit of the communication terminal according to the first embodiment.

FIG. 5 is an explanatory diagram for explaining the operation of the loudspeaker call processing unit of the embodiment.

FIG. 6 is an explanatory diagram illustrating an operation of another loudspeaker processing unit according to the first embodiment;

FIG. 7 is a schematic configuration diagram illustrating a loudspeaker communication system according to a second embodiment.

FIG. 8 is a schematic configuration diagram illustrating a voice call system according to a third embodiment.

FIG. 9 is an explanatory diagram illustrating an operation of the oscillation detection unit according to the embodiment.

FIG. 10 is a schematic configuration diagram illustrating a loudspeaker communication system according to a fourth embodiment.

FIG. 11 is an explanatory diagram illustrating an operation of the level adjustment / combination unit according to the third embodiment.

FIG. 12 is a schematic configuration diagram illustrating a loudspeaker system according to a fifth embodiment.

FIG. 13 is an explanatory diagram illustrating an operation of the output synthesizing unit according to the embodiment.

FIG. 14 is a schematic configuration diagram showing another configuration of the loudspeaker communication system of the above.

FIG. 15 is an explanatory diagram illustrating an operation of the output synthesizing unit according to the embodiment.

FIG. 16 is a schematic configuration diagram illustrating a loudspeaker system according to a sixth embodiment.

FIG. 17 is a schematic configuration diagram showing the adapter of the above.

FIG. 18 is a schematic configuration diagram illustrating a loudspeaker communication system according to a seventh embodiment.

FIG. 19 is an external view of a call terminal used in the above-described voice call system.

FIG. 20 is a schematic configuration diagram showing the above call terminal.

FIG. 21 is an explanatory diagram illustrating a device connected to the above call terminal.

FIG. 22 is an explanatory diagram illustrating a signal transmitted by the ping-pong transmission method according to the first embodiment.

FIG. 23 is a schematic configuration diagram showing a communication terminal used in the loudspeaker communication system according to the eighth embodiment.

FIG. 24 is an explanatory diagram illustrating a signal transmitted by the ping-pong transmission method according to the first embodiment.

FIGS. 25A and 25B show a call terminal provided with a camera used in the loudspeaker communication system according to the ninth embodiment, where FIG. 25A is an external view and FIG.

26A and 26B show a call terminal provided with a monitor used in the above embodiment, FIG. 26A is an external view, and FIG. 26B is a schematic configuration diagram.

FIGS. 27A and 27B are explanatory diagrams illustrating signals transmitted by the ping-pong transmission method according to the first embodiment.

FIG. 28 shows another call terminal equipped with the above camera,
(A) is an external view, (b) is a schematic block diagram.

FIG. 29 shows another call terminal provided with the above-mentioned monitor,
(A) is an external view, (b) is a schematic block diagram.

FIG. 30 is an explanatory diagram illustrating an occupied frequency band of a signal transmitted by the ping-pong transmission method according to the embodiment.

FIGS. 31 (a) and (b) are explanatory diagrams illustrating the relationship between a signal transmitted by the ping-pong transmission method and noise in the loudspeaker communication system according to the tenth embodiment.

FIG. 32 is an explanatory diagram illustrating a relationship between a frequency and a signal level according to the embodiment.

[Description of Signs] 1a ... Call terminal 2 Central processing unit 3a ... Transmission line 14 Transmission processing unit 21 Central transmission processing unit 22 Digital signal processing unit 25 Loudspeaking call processing unit

Continuation of front page (72) Inventor: Akira Terasawa, Matsushita Electric Works, Ltd.

Claims (12)

[Claims] A transmission processing unit that includes a speaker and a first microphone for transmitting and receiving a digital communication signal and a control signal to and from the outside; and converting a digital communication signal input from the transmission processing unit into an analog communication signal. And a plurality of communication terminals provided with a codec unit for converting an analog communication signal input from the first microphone into a digital communication signal and outputting the digital communication signal to a transmission processing unit; A central transmission processing unit for transmitting and receiving a digital communication signal and a control signal therebetween, a digital signal processing unit having a serial input / output port for processing a digital communication signal input via the central transmission processing unit, and operation of each unit And a central processing unit comprising a central processing unit for controlling the communication processing. The plurality of communication terminals and the central processing unit are connected via two transmission lines, respectively. Between the unit and the central transmission processing unit, the digital communication signal and the control signal are multiplexed, and signal transmission is performed by a ping-pong transmission system that switches the transmission direction of the transmission line at predetermined time intervals. The digital call signal and control signal transmitted from the call terminal are separated and time-division multiplexed for each signal. In addition, when making a loudspeaker call between the call terminals through the central processing unit, the digital call processing unit performs a loudspeaker call process that suppresses the sound from flowing from the speaker of each of the call terminals to the first microphone. A featured voice call system. 2. A volume level of a digital call signal output to each call terminal in response to a volume control signal input from each call terminal when making a voice call between the call terminals via a central processing unit. 2. The loudspeaker system according to claim 1, wherein the digital signal processing unit is provided with a sound volume setting unit for setting the volume. 3. When making a voice call between the respective call terminals via the central processing unit, voice wraparound from the speaker of the call terminal of the other party to the first microphone of the own call terminal, The digital signal processing unit is provided with an oscillation detection unit for detecting an oscillation caused by a sound wraparound from the speaker of the call terminal to the first microphone of the call terminal of the other party, and the digital signal processing unit responds to the detection result of the oscillation detection unit. 3. The loudspeaker communication system according to claim 1, wherein the volume level of the digital communication signal output to each of the communication terminals is reduced. 4. When making a voice call between three or more call terminals via a central processing unit, the volume level of a digital call signal input from a first microphone of each call terminal is substantially the same. 4. The loudspeaker communication system according to claim 1, further comprising a communication level output / synthesis unit for synthesizing each digital communication signal and outputting the synthesized signal to a corresponding communication terminal. 5. The digital signal processing unit according to claim 1, wherein an output synthesizing unit for superimposing a signal corresponding to the control signal input from the central control unit on the digital communication signal and outputting the signal is provided. Loudspeaker system. 6. An adapter for converting an analog signal from a telephone terminal into a digital signal and transmitting the digital signal to the central processing unit by a ping-pong transmission method on a transmission line connecting the central processing unit and the telephone terminal. The loudspeaker communication system according to any one of claims 1 to 5, wherein 7. An external line adapter for communicating with an external terminal via an ISDN line in a central processing unit, and a digital signal processing unit performs external line processing according to a control signal input through the external line adapter. 7. A loudspeaker system according to claim 1, wherein each call terminal answers an outside line call. 8. A telephone terminal is provided with a modular jack for connecting either a door phone or an ISDN line, and a changeover switch for switching whether to connect a door phone or an ISDN line to the modular jack,
8. The loudspeaker communication system according to claim 7, wherein the switching between the codec and the output of the digital communication signal and the control signal to and from the central processing unit in accordance with the switching state of the changeover switch is performed. 9. A transmission processing unit and a central transmission processing unit,
A signal obtained by multiplexing a plurality of digital communication signals and one control signal is transmitted by a ping-pong transmission method, and one of the plurality of digital communication signals is used for communication with either a door phone or an outside line, and another digital communication signal is used. 9. The loudspeaker communication system according to claim 1, wherein the communication signal is used for communication with a communication terminal installed indoors. 10. A video display unit for displaying an image on a telephone terminal and a second microphone for preventing howling, wherein two digital telephone signals and one digital signal are transmitted between a transmission processing unit and a central transmission processing unit.
A signal multiplexed with the control signals is transmitted by the ping-pong transmission method and transmitted from the central processing unit to the call terminal.
One of the digital call signals is used for a video signal,
Two digital call signals transmitted from the call terminal to the central processing unit are used for signals input from the first and second microphones, and the digital signal processing unit uses the signals input from the first and second microphones 9. The loudspeaker system according to claim 1, wherein the loudspeaker system performs a loudspeaker call process for suppressing the wraparound of the sound from the speaker to the first microphone based on the vocalization. 11. A communication terminal for outdoor installation, wherein the communication terminal includes a camera and a modulator for modulating an analog video signal captured by the camera; a demodulator for demodulating the modulated video signal modulated by the modulator; It consists of an indoor installation call terminal having a video display unit for displaying an analog video signal demodulated by the demodulation unit. A digital call signal, a control signal, and a modulation video signal are provided between both the call terminals and the central processing unit. 10. The loudspeaker communication system according to claim 1, wherein the loudspeaker is multiplexed and transmitted by a ping-pong transmission method. 12. The loudspeaker communication system according to claim 1, wherein said digital communication signal transmitted between said transmission processor and said central transmission processor is compressed and transmitted at a low bit rate. .