JPH01305787A - Inter-multiple-point video conference system - Google Patents

Abstract

PURPOSE:To remove the deterioration of transmission quality, and to make a system efficient by connecting a picture terminal exchange V-TEX between TV conference equipment and a CODEC installed at each place. CONSTITUTION:The TV conference terminal equipment 1 consists of a peripheral apparatus control part and a TV camera, etc. The V-TEX 2 distributes signals by a switching matrix to be received from a CODEC interface 31 and a video image synthesis circuit 32 to a RF MODEM A 37 through a terminal interface 34 and to the RF MODEM B 37 through a cascade V-TEX interface 35. The coding/decoding of the picture is performed by the CODEC 3, and a terminating equipment 4 performs protocol conversion to make connection to an integrated digital public network 6 possible. An interface 5 is provided with a built-in CPU, and controls switching separately according to the kind of a machine. Through this constitution, the V-TEXs for slaves 22-26 can be cascade-connected by plural traffic lines as making the V-TEX 21 be a master, and the signal can be transmitted without deteriorating picture quality by the frequency shift keying of sufficient band width.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention provides a video terminal exchange (V-TEX) between an image encoding/decoding device (codec) and a video conference terminal device.
Regarding video conferencing systems that can transmit and receive information such as data, audio, and video between multiple remote points by arranging a This contributes to the operation of highly efficient information exchange between locations.

"Prior art" In a conventional video conference system, the carrier wave is 24 to 26 M) on the transmitting side and 44 to 4 on the receiving side.
A band of 6 MHz is allocated to the transmission and reception of multiplexed data using the full duplex FSK method, and for video data, the band is 91' and 25 MHz for AM transmission, and 9 MHz for AM reception.
5.75MHz, 9 for FM transmission as audio data
5, 75 M II z, T' 100 for M reception
, 25 MHz, and frequencies of 96 to 102 MHz can be used as two television frequency channels.

and about 1001'lb〆8 to send the raw image
An image encoding/decoding device (loader/decoder-codec) is used to compress this video and audio information to 64Kbps, but it is also necessary for personal computers, peripheral devices such as facsimiles, image scanners, and remote controls. In order to make the system more efficient and multi-functional by connecting a video conference terminal device consisting of a display and a control unit, it is necessary to connect unit systems based on codecs in multiple stages to exchange information. However, the current situation is that the codec itself is economically expensive and the quality of information transmission deteriorates, making it impractical.

``Problems to be Solved by the Invention'' However, the present invention is based on an economical point of view in constructing the above-mentioned video conferencing system, and is designed to support Okawa's data, audio, video information and The purpose of the present invention is to enable highly efficient operation of the system without requiring any additional equipment for sending and receiving data, without degrading transmission quality even when unit systems are cascaded and expanded.

``F stage for resolving interpressure points'' Thus, the present invention makes it possible to hold video conferences between remote multipoints, and also to use personal computers, facsimiles,
As well as using peripheral devices such as image scanners,
By connecting a video terminal exchange (V-TEX) between the video conference terminal equipment installed at each location and the codec, multiplexed information is transmitted using the full duplex method. be.

The present invention will be explained below using specific examples.

"Embodiment" First, a description will be given using the block diagram of the minimum unit for implementing the video conference system of the present invention shown in FIG. (2) is a video conference terminal device placed at each remote location, and consists of a control section to which peripheral devices such as a facsimile, an image scanner, and a personal computer are connected, a display, a remote control, an RV camera, etc. 2 is connected to the RF mode A via a terminal ink face 34 by a switching matrix 33 that receives signals from a codec interface 31 and a video synthesis circuit, as shown in FIG.
This is an image terminal exchange that distributes the data to A, 36 and RF modem B, 37 via a cascade V-TEX interface 35. Reference numeral 3 denotes a loader/decoder (CODEC), that is, an image encoding/decoding device, which is equipped with six channels of traffic lines, two channels as a control boat and four channels as a user boat, and two external lines.

4 is a terminating device or terminal adapter that connects the outside line and the 1st office line and has a data width of 2 channels (64Kbps x 2ch + 16Kbps), and is an integrated digital public network (I).
SI)N) A protocol converter unit 5 is provided with a terminal corresponding to the type of peripheral equipment such as a facsimile, an image scanner, a personal computer, etc. to enable connection with the SI)N)6, and the terminal is used for t, rJ and sub-control commands. This is a connection line termination device with a built-in CPU, ie, an ink face.

Next, FIG. 2 shows the unit system of the present invention in the unit system shown in FIG.
The video conference terminal device 1 operates at multiple points, that is, five points in this embodiment, with the image terminal exchange 21 having a back function as the core.
-TEX is cascade-connected with 22, 23, 24, 25, and 26, respectively, and is a block diagram of an example of adding conference points. Each V-TEX installed here is connected to the codec by a coaxial cable, and the V-TEX
Up to six traffic lines can be laid between EXs.

In addition, in addition to the control device, display, remote control, and TV camera, the video conference terminal device l is equipped with connection terminals so that peripheral devices such as a facsimile, image scanner, and personal computer can be installed. You can scratch these peripherals without leaving your home.

For example, if a three-person video conference is held at three points A, B, and C, the video conference terminal device 221 at each point will have a fixed mode in which images and voices of people other than the speaker are received, and a fixed mode in which the images and voices of the interlocutor at Miike point are received. There is a variable mode in which the image changes each time someone speaks, and in this variable mode, a switch built into the V-TEX allows the image to be shown on the screen while the speaker in charge of speaking is speaking. There is.

- Switching and execution of the mode described in F is performed on the video conference terminal @
Audio and image signals are synchronized between 1, the image copy exchange 2, and the image encoding/decoding device. And for multiplexed data, one channel is 19.2
It contains 8 channels of Kbps asynchronous signals, is multiplexed, and can contain data from image scanners, personal computers, etc.

Since the data is multiplexed and transmitted using a frequency keying method, the transmitting side uses a frequency of 24 to 26 MHz.
26 M It z out of 24 M
Hz as O, and the receiving side sets 46 MHz to 1.44 MHz as O for carrier waves of 44 MHz to 46 MHz.
On the other hand, images are transmitted using the AMM method, and audio is transmitted using the FM method, similar to the data described above.

``Effects'' Therefore, the multipoint video conference system of the present invention installs a video terminal exchange between the video conference terminal and the encoding/decoding device, and uses the video terminal exchange as a master to connect six traffic lines. Because slave river image terminal exchanges can be connected in cascade, it is possible to connect not only video conference terminal equipment at multiple points, but also image scanners,
It can be connected to peripheral devices such as facsimile machines and personal computers, and the frequency shift key ink method with a sufficient bandwidth allows transmission without deteriorating image quality.As a result of the simple noise filtering, it is overall economical. Furthermore, if the system of the present invention is stored with an information recording medium for recording information in a video terminal exchange, the system of the present invention can be expanded to the field of use as an electronic file. You can also do that.

[Brief explanation of the drawing]

FIG. 1 is a basic unit block diagram of the present video conference system, FIG. 2 is a block diagram of a different embodiment in which video terminal exchanges are connected in cascade, and FIG. 3 is a block diagram of the configuration of the video terminal exchange. l: Video conference terminal device 2: Image terminal exchange 3: Image encoding/decoding device 4: Terminal adapter 5: Connection line termination device 6: Integrated digital public network

Claims (1)

[Claims] In a video conferencing system in which analog information such as images and audio and digital data are multiplexed as carrier waves and transmitted and received between multiple points using a full duplex method, peripheral devices such as facsimile machines, image scanners, and personal computers are connected. The carrier wave is transferred to and received from an image terminal exchanger connected to a video conference terminal device consisting of a control unit, a display, and a remote control via a coaxial cable, and is converted to D/A or A/D by a switching matrix, and the image is transmitted via a modem. and a codec that compresses, expands, encodes and decodes audio signals, converts the protocol for connecting this codec to the integrated digital public network using a terminal adapter, and then connects the connection terminals of the plurality of peripheral devices mentioned above. A multi-point system characterized in that audio, video and data can be transmitted and received between remote multi-points by connecting to the integrated digital public network through a line termination device incorporating a CPU for switching control. video conferencing system.