JPH03106146A - Video exchange system - Google Patents

Abstract

PURPOSE:To allow the system to cope flexibly with system change or expansion or the like by using a loop communication system so as to realize the video exchange system. CONSTITUTION:When a broadcast video camera 10a picks up a broadcast video image, a video signal for the broadcast video is sent by using a video signal line assigned fixedly by the camera 10a. When each monitor 11 requires a broadcast video image, the video signal line has only to be selected. When an optional monitor 11 requires a video of a desired camera 10, the monitor 11 uses a control line to give a command of sending a video signal to the desired camera 10. Then the camera 10 uses an idle video signal line to send the video signal to the commanded camera 10. Thus, the video signal line is efficiently used.

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) The present invention is directed to the ITV (Industrial T
clcvision) system and CATV (
The present invention relates to a video switching system applied to a cable television system and the like.

(Prior art) For example, for management such as monitoring traffic conditions on expressways,
Conventionally, ITV systems have been used.

Figure 3 shows II! of such a system. FIG. 3 is a diagram showing an Ell+3 configuration.

In the same figure? No. 1 1 indicates an expressway, and along the expressway 1 a plurality of cameras 2.2.・
... is placed. A monitor 4 is disposed at a management station 3 that centrally manages the expressway 1 at a predetermined location.

A two-point transmission system is applied between each camera 2 and monitor 4. Therefore, separate optical cables 5 are connected between each camera 2 and monitor 4.

In the system configured as described above, the management station 3 monitors the traffic situation using images displayed on the monitor 4.

However, in such systems, when operational changes occur such as adding cameras or changing monitoring areas, it is necessary to newly install optical cables, etc.
There was a problem in that it required a large amount of engineering work and cost.

Nearby, multiple monitors are placed for multiple cameras,
There is a demand for displaying images from any camera on any monitor. If a system that meets these demands is developed by applying the system shown in Figure 3, a large amount of cables 5 will be required to connect each of the plurality of cameras 2 and each of the plurality of monitors 4, as shown in Fig. 4. This gives rise to the problem of becoming.

In order to deal with this problem, it is conceivable to reduce the amount of cables by interposing a video exchanger 6 having a video signal exchange function between each camera 2 and each monitor 4, as shown in FIG. . However, in this case, there is a problem in that a video exchange 6 having a very complicated structure is required.

(Problem to be solved by the invention) In this way, in the conventional ITV system used for monitoring the traffic conditions on expressways, etc., it is possible to perform centralized management, but it is possible to flexibly handle changes and expansions of the system. It is not possible to do so, which poses problems in terms of cost, etc.

The present invention has been made to solve these problems, and aims to provide a video exchange system that can flexibly deal with system changes, expansions, etc.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the problems, the present invention provides a system in which a plurality of stations are connected in a loop via a transmission path, and control signals are exchanged between these stations. A system for exchanging video signals between a plurality of cameras and a plurality of monitors using a loop communication system in which a frame having a control packet part to be transmitted and a line part to which a line signal is exchanged is circulated on the transmission path. The camera and the monitor are respectively connected to each station, and the front 5
The circuit section of the own frame includes a video signal port line for exchanging video signals between these cameras and monitors, and a control line for exchanging control signals between each camera and each monitor on a one-to-one basis. , and the monitor instructs the desired camera to transmit a video signal using the control line.

Further, in the above invention, a broadcast line may be allocated to the video signal line.

(Function) In the present invention, a video exchange system is realized using a loop communication system, and control between the camera and the monitor is performed mainly by the monitor using a control line provided in the line part of the frame. ing.

That is, when any monitor requires an image from a desired camera, the monitor first instructs the desired camera to transmit a video signal using the control line. Then,
This camera uses a video signal line to transmit a video signal to the designated camera.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a diagram showing the configuration of a system according to a first embodiment of the present invention.

In the figure, 7 indicates a loop type communication system.

In this loop communication system 7, a plurality of stations 8 are connected in a loop via a transmission line 9 made of, for example, an optical cable.

Then, by circulating the frame on the transmission path 9, a time division multiplexed line is formed, and communication is performed between each station 8.

FIG. 2 is a diagram showing the structure of a frame circulating around this transmission line 9.

The frame shown in the figure has a frame length of, for example, 125 μs.
It consists of a frame header, a control bucket part, and a same line part.

The frame header indicates the beginning of the frame, and subsequent positions are determined based on this frame header.

The control packet portion is a small packet used for communication between stations 8, and is used for connection control and network management.

The line section is composed of slots of, for example, 64 kb[t, and one part of which is provided with three 32 Mbps video signal lines and a control line.

Further, each circuit 8 has a built-in interface circuit (not shown) for connecting a terminal, and a camera 10 or a monitor 11 is connected as the terminal.

The video signal port is used to exchange video signals between the camera 10 and the monitor 11.

Among the cameras 10, one of the lines of sight for video signals is specifically assigned to the camera 10a for broadcast video. Here, the broadcast video refers to an important video that needs to be displayed on all monitors 11. Furthermore, each monitor 11 recognizes in advance which line the fixedly allocated broadcast video signal line is allocated to.

The control line is used for exchanging control signals between the camera 10 and the monitor 11, and is used for each camera 10 and monitor 11 to exchange control signals.
0 and each monitor 11 are arranged on a one-to-one basis.

That is, all the cameras 10 are separately displayed for one monitor 11, for example, in e4kbttqtth.

Each monitor 11 then takes the lead in controlling the exchange of video signals. That is, the monitor 11 performs control to instruct a desired camera 10 to transmit a video signal using the control line.

Next, the operation of the video exchange system configured as described above will be explained.

First, the operation of exchanging video signals for broadcast video will be explained.

When the broadcast video camera 10a is capturing a broadcast video, the video signal for the broadcast video is transmitted from the camera 10a using the fixedly allocated video signal line as described above.

When each monitor 11 requires broadcast video, the video signal 1i! Just select one line.

Therefore, in the video exchange system of this example, the monitor 11 can obtain a broadcast image by extremely simple control.

Next, the operation of exchanging video signals one-on-one between the monitor 11 and the camera 10 will be described.

When one monitor 11 needs an image of a desired camera 10, first, this monitor 11 instructs the desired camera 10 to transmit a video signal using a control line.

Then, this camera 10 transmits a phantom video signal to the designated camera 10 using the vacant video signal line.

Then, the camera 10 selects this video signal line.

Therefore, in the video switching system of this embodiment, the video signal lines can be used efficiently.

Furthermore, since the above-mentioned exchange of control signals between the monitor 11 and the camera 10 is performed using a control line connected one-to-one between each camera 10 and each monitor 11, Group line access control becomes unnecessary. Moreover, since such control is performed using the line section allocated from the loop communication system, the station 8
The control system is completely independent of the control system using the control packet section. Therefore, from the perspective of the loop communication system, it is sufficient to simply lend out the sealed line section to the video switching system, and it is easy to isolate the connection when another communication system is connected.

Additionally, since the video exchange system is basically implemented using a loop communication system, system changes and
Expansion, etc. can be handled flexibly.

[Effects of the Invention] As explained above, according to the present invention, a video exchange system is realized using a loop communication system.
It is possible to flexibly deal with system changes, expansions, etc.

In addition, since the control line for each camera and each monitor to exchange control signals on a one-to-one basis is assigned to the line part of the frame, there is no need for access control of the control line that is normally used. From the perspective of the loop communication system, it is easy to isolate when other communication systems are connected.

Furthermore, since the monitor uses the control line to instruct a desired camera to transmit a video signal, the video signal line can be used efficiently.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the structure of a system according to an embodiment of the present invention, FIG. 2 is a diagram showing the structure of frames used in this system, and FIGS. 3 to 5 are diagrams showing a conventional video exchange system. FIG. 7... Loop communication system, 8... Station, 9...
Transmission line, 10... Camera, 10a... Camera for broadcast video, 11... Monitor.

Claims (2)

[Claims] (1) A plurality of stations are connected in a loop via a transmission path, and a frame having a control packet part in which control signals are exchanged between these stations and a line part in which line signals are exchanged is circulated on the transmission path. A system for exchanging video signals between a plurality of cameras and a plurality of monitors using a loop communication system, wherein the cameras and the monitors are respectively connected to each station, and these are connected to the line part of the frame. A video signal line for exchanging video signals between the camera and the monitor and a control line for exchanging control signals between each camera and each monitor on a one-to-one basis are allocated, and said monitor is connected to said monitor. A video exchange system characterized in that a control line is used to instruct a desired camera to transmit a video signal. (2) The video switching system according to claim 1, wherein a broadcast line is allocated to the video signal line.