JPH0191563A - Conference speech system by digital key telephone system - Google Patents

Abstract

PURPOSE:To attain conference speech with plural persons by adding plural digital voice signals digitally in a key telephone set, applying digital/analog conversion and outputting the result to a handset or a speaker. CONSTITUTION:A frame transmitting a signal consists of a control signal and plural voice signals from key telephone sets 11-14 in a digital key telephone set transmitting the control signal and the voice signal between the key telephone main set 1 and the key telephone sets 11-14 in a serial digital signal. Then a digital adder circuit 7 is provided on the key telephone sets 11-14 to add the voice signal of the key telephone sets 11-14 sent from the key telephone main set 1 by the sets 11-14. Thus, the conference speech is attained and the number of groups capable of conference speech is not limited in one key telephone set.

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a digital button telephone device that digitally transmits voice signals between a key telephone main device and a key telephone device, and in particular, a digital button telephone device that digitally transmits voice signals between a key telephone main device and a button telephone device, and in particular, a digital button telephone device that digitally transmits voice signals between a key telephone main device and a button telephone device. The present invention relates to a digital button telephone device having a conference call function.

(Prior Art) Conventionally, in the conference call system of this type of digital key telephone device, nine digital voice codes sent into the key telephone main device are converted into an analog signal, and after adding multiple voice signals, the digital voice signal is converted into an analog signal. Instead of converting the signal back into a signal and transmitting it to the key telephone, the key telephone main unit used to perform a summation of the digital signal before transmitting it to the key telephone.

(Problems to be Solved by the Invention) In the conference call system of the conventional digital key telephone device, all additions of audio signals are performed within the key telephone main device in this way. The number of groups that could hold conference calls was limited by the number of adder circuits to be developed.

Further, the number of people in a group who can make a conference call is limited by the configuration of the adding circuit.

The object of the present invention is to overcome the above-mentioned drawbacks.

To provide a conference call system for a digital button telephone device that does not limit the number of groups that can all make conference calls within one button telephone device.

(Detailed Means for Solving All Problems) In order to achieve the above object, the conference call system of the digital button telephone device according to the present invention transmits control signals and voice signals between the key telephone main device and the button telephone device using serial digital signals. In a digital button telephone device that transmits a signal, a frame for transmitting a signal is composed of a control signal and a plurality of audio signals from each button telephone device, and each button telephone device is provided with a digital addition circuit, so that a frame for transmitting a signal is composed of a control signal and a plurality of audio signals from each button telephone device. It is configured to enable conference calls by adding the audio signals from the padding machine to each button on the bottom button telephone.

(Example) The present invention will be described in more detail below with reference to one drawing.

FIG. 1 is a block diagram showing an embodiment of a conference call system of a digital button telephone device according to the present invention. In this figure, only the parts directly related to the present invention are fully illustrated. A central processing unit 12 in the button telephone main device 1 controls a switch circuit 4 and a signal transmitting/receiving circuit 5 according to a program stored in a memory circuit 3. The switch circuit 4 exchanges voice signals from each button telephone 11, 12, 13, 14. tf: The signal transmitting/receiving circuit 5 transmits all the control data of each button telephone, voice signals, etc. in serial digital signals.

The button telephone has a signal transmitting and receiving circuit6. Digital addition times%
7, a D/AK converter 8, an A/D converter 9, and 10 analog signal output units.

Figure 2 shows the button telephone main device 1 and the button m filling machines 11 to 14.
FIG. 3 is a diagram showing an example of a frame format of one frame of a digital transmission signal between the two.

One frame of the transmission signal to the button telephones 11 to 14 includes the control signal e of the button telephone and the other key telephones 11 to 1.
A plurality of audio signals a to d from 4 are included.

One frame of the transmission signals from the button telephones 11 to 14 includes the information signal f of the button telephone and the own voice signal a.
d is included.

Regarding the button telephone All, the switch circuit 4 and the signal transmitting/receiving circuit 5 are controlled by the central processing unit 2 in the button telephone main device 1.

Control signal e for controlling button telephone All and button telephone 12, button telephone 13゜button telephone 1
4 audio signals b-d are transmitted as serial digital signals. The three digital voice signals b-d from the other button telephones 12 to 14 are added in a digital adder circuit 7, and then converted to analog signals in a digital-to-analog converter 8. The signal is converted into an audio signal and output from an analog input/output unit 10 such as a handset or a speaker. The analog audio signal a from the key telephone 11 is input from an analog input/output unit 10 such as a handset or a microphone, is converted into a digital audio signal by an analog-to-digital converter 9, and then is transmitted by a signal transmitting/receiving circuit 6. It is transmitted to the key telephone main device 1.

Voice signals are exchanged by the switch circuit 4 in the button telephone main device 1, and the voice signal a of the button telephone 11 is sent to the button telephones 12, 13, and 14.

The above operation is performed on the button telephone 12. The same applies to button telephone 13 and button telephone 14. Therefore, in this embodiment, a four-party conference call in which calls are made simultaneously between the four button telephones 11 to 14 is possible.

(Effects of the Invention) As explained above and as follows, the present invention includes a plurality of audio signals in one frame of a serial transmission signal from a key telephone main device to a key telephone, and transmits them as a digital/I/signal.
The plurality of digigel audio signals are digitally added within the key telephone, digital-to-analog converted, and output to a handset or speaker, so that a conference call can be held with a plurality of people. Furthermore, since each key telephone has a circuit for adding digital audio signals, there is no restriction on the number of groups that can make conference calls within one key telephone main device. Furthermore, there is the advantage that an extension call can be made to a key telephone that is currently in use by utilizing the digital voice addition function within the key telephone. Note that the number of people in a group who can make a conference call is limited by the configuration of the adder circuit, as in the prior art.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the conference call system of the digital button telephone device of the present invention, and FIG. 2 is a diagram showing an example of the frame format of one frame of the digital transmission signal of the button telephone main device and the button telephone device. be. 1... Key telephone main device 2... Central processing unit 3
...Memory circuit 4...Switch circuit 5.6...
- Signal transmission/reception circuit 7...Digital addition circuit 8...Digital-to-analog converter 9...Analog-to-digital converter 10...Analog signal input/output section (handset, speaker, microphone, etc.) 11... Button telephone A 12... Button telephone B 13... Button telephone C 14... Button telephone D a... Button telephone person's voice signal b... Voice signal of button telephone B C... Button telephone Audio signal of C d...Audio signal of button telephone e...Control signal f...Information signal Patent applicant
NEC

Claims (1)

[Claims] In a digital button telephone device that transmits control signals and audio signals between a key telephone main device and a button telephone device as serial digital signals, a frame for transmitting the signal is composed of a control signal and a plurality of audio signals from each button telephone device. In addition, each button telephone is provided with a digital addition circuit, and each button telephone is configured to add the audio signals from each button telephone sent from the button main device, thereby making it possible to make a conference call. Conference call method for button telephone equipment.