JPH0691566B2 - Digital phone - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital telephone that exchanges information with a switch by means of a digital signal, and more particularly to an interface circuit for connecting an analog video telephone to a digital telephone. Regarding

[Conventional technology]

FIG. 3 is a rear perspective view showing a conventional digital telephone disclosed in, for example, Japanese Patent Laid-Open No. 59-83443, in which 1 is a telephone body and 2 is a handset mounted on the telephone body 1. Reference numeral 3 is a dial key provided on the upper surface of the telephone main body 1, and 4 is a rear surface of the telephone main body 1, and is a line module jack for connecting the digital telephone to a telephone line from an exchange.

FIG. 4 is a block diagram showing the structure of such a digital telephone. In the figure, 2, 3 and 4 are the handsets, dial keys and line modules, and the handset 2 has a transmitter 2a and a receiver. 2b is provided. Numeral 8 is a fax switch, which is arranged below the handset 2 of the telephone body 1, and the handset 2 is the telephone body 1
When it is placed in, the switch 8 is off,
When the handset 2 is picked up from the telephone body 1, it turns on. Reference numeral 9 is a transmission terminal section for converting a transmission signal into a signal suitable for transmission and conversion of a reception signal into a signal used in a normal circuit, 10 is a line terminal section for multiplexing and separating a plurality of channels, and 11 is a line terminal section. A signal control unit that generates a selection signal corresponding to the pressed dial key 3, 12 is a codec (CODEC) that encodes and decodes a voice signal, 12a is an analog input end of this codec 12, and 12b is the same codec. Reference numeral 12 is an analog output terminal, and 13 is a communication circuit for connecting the analog input terminal 12a and the analog output terminal 12b of the codec 12 to the transmitter 2a and the receiver 2b of the handset 2.

Next, the operation will be described. Digital telephones exchange information with exchanges by a time division multiplexing method using digital signals. When the handset 2 is picked up from the telephone main body 1 at the time of making a call, the fax switch 8 is turned on and the transmission terminating portion 9 is connected to the line module jack 4. Here, if the dial key 3 is pressed,
The signal control unit 11 generates a selection signal of a digital signal corresponding to the pressed dial number and gives it to the line terminating unit 10. This selection signal is inserted into the signal channel at the line terminating unit 10, and is transmitted from the line modular radio 4 via the transmission terminating unit 9 to the exchange through the telephone line. The exchange calls the other party's telephone to be connected from the selection signal, and when it recognizes that the other party's telephone has responded, it establishes a connection between the voice channels of the calling side and the receiving side. Then, the voice signal input from the transmitter 2a in the handset 2 is input to the analog input terminal 12a of the codec 12 via the communication circuit 13, coded by the codec 12 and converted into a digital signal. This digitized voice signal is given to the line terminating unit 10, inserted into the voice channel by the line terminating unit 10, sent out from the line modular radio 4 to the telephone line via the transmission terminating unit 9, and transmitted to the other telephone through the exchange. To be done.

The voice signal sent from the other party's telephone is received by the transmission terminating unit 9, the voice channel is separated by the line terminating unit 10 and given to the codec 12. The codec 12 decodes the coded digital audio signal to convert it into an analog signal, and supplies it to the speech circuit 13 from the analog output end 12b of the codec 12. The call circuit 13 drives the handset 2b,
The voice signal is output as a sound from the handset 2b and transmitted to a person.

On the other hand, in recent years, telephones have been diversified, and videophones capable of image communication (sending and receiving still images) in addition to voice communication have entered the stage of practical use. This video phone has an interface that connects to a conventional analog phone.
It is expected to spread rapidly in the future. With the spread of the digital type telephones, it is considered that there is a growing demand for connecting such a video telephone to the digital type telephone.

FIG. 5 shows an example of using the videophone. In the figure, 20
Is an analog type telephone that has been widely used. Reference numeral 21 denotes a main body of the video telephone, 22 is a cable for connecting the analog telephone 20 and the main body 21 of the video telephone, and 23 is a cable for connecting the main body 21 of the video telephone and the telephone line 40 terminated with a module. , Cable 22,23
Module plugs are attached to both ends of. 24 is a TV camera for image capturing, 25 is a TV receiver that captures the image (transmitted image) taken by the TV camera 24 or the image (received image) sent from the other party's TV phone, and 26 is for sending the image. It is a send button. Further, FIG. 6 is a partial rear perspective view of this video telephone, 27 is a power supply jack provided on the main body 21 for receiving power to the video telephone, and 28 is a cable connected to the analog telephone 20.
Module for connecting 22 (hereinafter referred to as module for TEL), 29 is a cable connected to telephone line 40
It is a module that connects 23 (hereinafter referred to as a module for LINE).

Next, the operation of the videophone will be described with reference to the configuration diagram of FIG. 30 is a hybrid circuit 31 for the signals from the module for LINE 29 and module for TEL 28
With a switch that switches the connection to (together with the sound / image switch), connect the signal from the LINE module 29 to the hybrid circuit 31 for video calls and the signal from the TEL module 28 for voice calls. Connect to the hybrid circuit 31. The hybrid circuit 31 is for connecting a bidirectional communication line (which is a telephone line) and an independent transmission / reception line, and is usually called a 2-line to 4-line conversion circuit. Reference numeral 32 denotes an image switching signal detection circuit which, upon detecting a switching signal to image communication during a voice call, provides the detection information to the control circuit 33 so that the control circuit 33 puts the sound / image switch 30 into the image communication state. The circuit is switched so that the signal from the LINE module 29 is connected to the hybrid circuit 31. Further, the control circuit 33 puts the sound / image switch 30 into the image communication state when the send button 26 is pressed.

34 is an analog digital conversion circuit (hereinafter referred to as A / D conversion circuit) that converts the image signal from the television camera 24 into a digital signal, and 35 is A / D in response to a command from the control circuit 33 when the transmission button 26 is in transmission mode. This is a memory circuit for storing the image signal digitalized by the D conversion circuit 34, and this memory circuit 35 stores still image data for one screen taken by the television camera 24. The image data stored in the memory circuit 35 is sequentially sent to the modulation circuit 36. The modulation circuit 36 modulates the image data to a specific frequency within the voice band that can be transmitted by the telephone line. Conversely, 37 is a demodulation circuit that demodulates the received signal into image data, and the image data demodulated from the demodulation circuit 37 is stored in the memory circuit 38. The stored still image data for one screen is cyclically digitally
It is sent to an analog conversion circuit 39 (hereinafter referred to as a D / A conversion circuit), converted into an analog signal by the D / A conversion circuit 39, and then given to the television receiver 25 as an image signal.

The analog telephone 20 and the telephone line 40 are connected via the cable 23, the LINE module 29, the sound / image switch 30, the TEL module 28, and the cable 22 when making / receiving a call and during a voice call. As a result, it functions as a normal analog telephone as a whole. When an image is sent from a videophone connected to the other party's analog type telephone during a voice call, the image switching signal detection circuit 32 detects the image switching signal received prior to the image data. Then, the detection information is given to the control circuit 33.
Based on this detection information, the control circuit 33 causes the sound / image switch 30
To the image communication side. Module for LINE 29
Is connected to the hybrid circuit 31, the image signal from the telephone line 40 is input to the demodulation circuit 37 via the hybrid circuit 31. The image data demodulated by the demodulation circuit 37 is sent to and stored in the memory circuit 38, and the memory circuit 38 receives the control signal from the control circuit 33 and sequentially stores the image data stored in the cycle in the D / A conversion circuit 39. Send out. The D / A conversion circuit 39 converts this into an analog image signal and outputs it to the television receiver 25.

When sending images to the other party's videophone during a voice call,
When the send button 26 is pressed, the control circuit 33, which recognizes it, switches the sound / image switch 30 to the image communication side. At the same time, the image signal picked up by the TV camera 24 is converted into an A / D conversion circuit 34.
After digitalizing with, it is sent to the memory circuit 35 to store the image data. The stored image data is sequentially read by the control signal from the control circuit 33 and
36, and is sent from the LINE module 29 to the other party's videophone via the hybrid circuit 31.

[Problems to be solved by the invention]

Since the conventional digital telephone is configured as described above, it is impossible to connect the analog telephone having the above-described configuration to the digital telephone to perform image communication. There was a problem.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a digital telephone capable of performing image communication by connecting an analog television telephone, which is expected to spread in the future. .

[Means for solving problems]

The digital telephone according to the present invention is a telephone connected to a first connecting means for connecting an analog input terminal and an analog output terminal of a codec used in the digital telephone through a hybrid circuit, and a handset or a handset. The circuit is provided with a second connecting means for connecting via a hybrid circuit, and further a switch for connecting and disconnecting the first connecting means and the second connecting means.

[Action]

The digital telephone according to the present invention enables image communication by connecting the video telephones using the first connecting means and the second connecting means, and when the video telephones are not connected, the first connecting means is used. By connecting the means and the second connecting means by a switch, it operates as a normal telephone.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings. First
In the figure, 1 is a telephone main body, 2 is a handset, 3 is a dial key, 4 is a line module jack, and they are the same as those of the conventional ones given the same reference numerals in FIG. Further, 5 is a first modular jack provided on the back of the telephone body 1 as a first connecting means for connection with a video telephone, and 6 is also the telephone body 1
A second module provided as a second connection means for connecting to a videophone provided on the back surface of the
Reference numeral 7 is a switch for instructing connection / disconnection of the videophone.

FIG. 2 is a block diagram showing the structure of this digital telephone. In the figure, 2 is a handset, 2a is a receiver, and 2b is a receiver.
Is a transmitter, 3 is a dial key, 4 is a line module, 8 is a fax switch, 9 is a transmission terminating unit, 10 is a line terminating unit, 11 is a signal control unit, 12 is a codec, 12a is an analog input end of the codec 12, Reference numeral 12b is an analog output terminal of the codec 12, reference numeral 13 is a communication circuit, which is equivalent to those of the conventional ones given the same reference numerals in FIG. Also, 5 and 6
Is a first modular jack and a second modular jack provided on the back surface of the telephone body 1 for connection with a videophone, 7 is a switch also provided on the rear surface of the telephone body 1, and 14 is a first switch. Nojirajiyatsuki 5
Is a first hybrid circuit connected to the analog input terminal 12a and analog output end 12b of the codec 12, 14 is a second module 6 connected to the communication circuit, and is connected via the switch 7 The second hybrid circuit is also connected to the analog input terminal 12a and the analog output terminal 12b of the codec 12.

Next, the operation will be described. First, when a video telephone is not connected to the digital telephone, the switch 7 provided on the back surface of the digital telephone main body 1 is turned on to set the normal mode. At this time, the analog input end 12a and the analog output end 12b of the codec 12 are connected to the communication circuit 13 via the switch 7. The operation in this state is no different from the conventional operation, and the voice signal from the handset 2 or to the handset 2 is communicated with the other party by the voice channel via the codec 12.

When the videophone is connected, the switch 7 is turned off and the image mode is set. At this time, the video line telephone module 29 and the digital telephone first module 5 are connected by a cable equivalent to the one used for connection with a conventional analog telephone, and similarly, the video telephone TEL module 28 , And the second modular jack 6 of the digital telephone is also connected by a similar cable. When the videophone is in the voice communication mode, the voice channel from the line terminating unit 10 is converted into a two-line signal by the first hybrid circuit 14 via the codec 12, and the independent transmission / reception signals are converted into bidirectional signals. The first module 5 is connected to the LINE module 29 of the videophone. LINE in the videophone
For the module 29 for audio, use the sound / image switch 30 for TEL
Since it is connected to the application module 28, an audio channel is connected to the second module 6, and the second hybrid circuit 15 converts the voice signal into four lines again, and the bidirectional signal is transmitted and received independently. It is converted and connected to the communication circuit 13. When the videophone is in the image communication state, the digital telephone operates in the same manner as the conventional analog telephone.

In the above embodiment, the module using the modular jack is shown as the first connecting means and the second connecting means, but a connector other than the modular jack may be used.

Further, in the above-described embodiment, the case where the switch for externally operating whether or not the video telephone is connected to the digital telephone is used as the switch has been described, but when the video telephone is connected, the connection state is detected. A device that automatically performs the switching operation may be used, and the same effect as that of the above-described embodiment is obtained.

〔The invention's effect〕

As described above, according to the present invention, the digital telephone has the connecting means connected to the analog input terminal and the analog output terminal of the codec through the hybrid circuit and the connecting means connected to the communication circuit through the hybrid circuit. Since it is configured to be installed in the main body of the telephone, there is an effect that image communication can be performed by connecting a conventional analog type television telephone to these two connecting means.

[Brief description of drawings]

FIG. 1 is a rear perspective view showing a digital telephone according to an embodiment of the present invention, FIG. 2 is a block diagram showing its configuration, FIG. 3 is a rear perspective view showing a conventional digital telephone, and FIG. FIG. 6 is a block diagram showing the configuration, FIG. 5 is a perspective view showing a connection between a video telephone and an analog telephone, and FIG.
FIG. 7 is a partial rear perspective view of the video phone, and FIG. 7 is a block diagram showing the configuration of the video phone. Reference numeral 1 is a telephone body, 2a is a transmitter, 2b is a receiver, 5 is a first connecting means (first module), 6 is a second connecting module (second module), 7 is a switch, and 12 is a codec. , 12a is an analog input end of the codec, 12b is an analog output end of the codec, 13 is a communication circuit, and 14 is the first
Hybrid circuit, 15 is a second hybrid circuit. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A digital telephone that performs mutual conversion between a digital signal of a voice signal and an analog signal by using a codec and exchanges information with a switching device by using a digital signal, in the main body of the digital telephone.
First connecting means for connecting to an analog video telephone, which is connected to the analog input terminal and the analog output terminal of the codec through the first hybrid circuit;
A transmitter and a receiver through the second hybrid circuit,
Alternatively, the analog type connected to the speech circuit to which the transmitter and the receiver are connected, and connected to the analog input terminal and the analog output terminal of the codec through a switch together with the transmitter and the receiver or the speech circuit. A digital telephone, which is provided with a second connecting means for connecting to the video telephone.