JPH02226891A - Video exchange system - Google Patents

Abstract

PURPOSE:To allow a system to cope with the change and expansion of the system flexibly by connecting each camera, each monitor and a management station in a loop via a transmission line having a line for a video signal and allowing the management station to apply assignment management for the line and transmission control of a video signal in each camera. CONSTITUTION:Plural cameras 2, plural monitors 4 and a management station 7 are connected in a loop through a transmission line 5 having a line for a video signal and a function applying the assignment management of the line and transmission control of the video signal in each camera 2 is provided to the management station 7. When a monitor 4 designates a camera 2 of the display to the management station 7, the management station 7 assigns a prescribed line to the monitor 4 to control to send the video signal through the line assigned to the designated camera 2. Thus, the system copes flexibly with the system change and expansion.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The present invention
1cvlslon) system and CATV (Ca
ble Tc1ev1s1on) system, etc.

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

FIG. 4 is a diagram showing a schematic configuration of such a system.

In the figure, reference numeral 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, each camera 2 and monitor 4 are connected by separate optical cables 5, respectively.

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.
The problem was that it required a huge amount of work and cost.

In addition, in recent years, multiple monitors have been arranged for multiple cameras,
There is a demand for displaying images from any camera on any monitor. If a system that meets such demands is realized by applying the system shown in FIG. 4, a cable 5 for connecting a plurality of cameras 2 and a plurality of monitors 4 as shown in FIG. 5 will be required. This gives rise to the problem of becoming.

To deal with this problem, it is conceivable to insert a video exchanger 6 having a video signal exchange function between each camera 2 and each monitor 4, as shown in FIG. 6, to reduce the amount of cables. However, in this case, there is a problem in that a video exchange 6 having a very complicated configuration 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 a main object of the present invention is to realize a video exchange system that can flexibly deal with changes and expansions of the system. In other words, the purpose is to reduce the cost of installing cables necessary to transmit video signals, and to facilitate switching and broadcasting of video signals.

[Structure of the Invention] (Means for Solving the Problems and Their Effects) In order to solve the problems, the present invention receives video signals transmitted from a plurality of cameras by one or more monitors, and displays the images. In a system configured to display a video signal, the invention according to claim 1, characterized by the following means, connects a camera, a monitor, and a management station in a loop through a transmission path having a line for video signals, and , the management station is provided with functions for managing line allocation and controlling transmission of video signals in cameras. Then, when the monitor specifies the camera to be displayed to the management station, the management station allocates a predetermined line to the monitor and controls the specified camera to transmit a video signal through the allocated line. be.

According to the second aspect of the invention, the camera and the monitor are connected in a loop through a transmission path having a video signal line, and each camera is assigned its own video signal line.

When there is a camera to display, the monitor selects a line for a video signal specific to that camera.

In the third aspect of the present invention, the camera and the monitor are connected in a loop through a transmission path having a video signal line, and each monitor is assigned its own video signal line.

When there is a camera to display, the monitor instructs the transmission of a video signal to a specific video signal line assigned to the camera.

In the invention as claimed in claim 4, the camera and the monitor are connected in a loop through a transmission path having a video signal line, and each monitor is assigned a unique video signal line, and all At least one line for a video signal shared by the camera and monitor is assigned. When there is a camera that should be displayed on multiple monitors, the video signal is sent to the shared video signal line for the camera, and when there is a camera that should be displayed individually on the monitor, the video signal is sent to the camera. This instructs the transmission of a video signal to the assigned unique video signal line.

In the invention as claimed in claim 5, the camera and the monitor are connected in a loop through a transmission path having a video signal line, and a predetermined frame including the video signal line is circulated on the transmission path. .

When the monitor has a camera to display, it requests the camera to send a video signal, and upon receiving this request, the camera searches for an empty line on the frame and uses the empty line it finds to send the video signal. It is something to do.

In the invention as set forth in claim 6, the camera and the monitor are connected in a loop through a transmission path having a video signal line, and a predetermined frame including the video signal line is circulated on the transmission path. .

When there is a camera that the monitor should display, it searches for an empty line among the video signal lines11, and when it finds one, it uses the only declaration slot that exists on the frame on the transmission path to monopolize that line. In addition to declaring this, it also instructs the camera that is to perform the display to transmit a video signal using the line.

In the seventh aspect of the invention, the camera and the monitor are connected in a loop through a transmission path having a video signal line, and a predetermined frame including the video signal line is circulated on the transmission path. .

When there is a camera that should be displayed on the monitor, the monitor issues a transmission request to the camera, and upon receiving the transmission request, the camera searches for an empty line among the lines for video signals, and when it finds one, it displays the only one on the frame on the transmission path. It uses the existing declaration slot to declare that the line is exclusive, issues a transmission request, notifies the monitor of the line, and transmits a video signal to the line.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a video exchange system according to an embodiment of the invention as claimed in claim 1.

As shown in the figure, a plurality of cameras 2.2..., a plurality of monitors 4.4..., and the only management station 7 on the system are connected to stations (not shown) that can interface with these. (omitted), and these stations are connected in a loop via an optical cable 5. That is, a plurality of cameras 2a, 2b, . . . , a plurality of monitors 4a, 94b, .

The loop-shaped transmission path includes a plurality of lines capable of transmitting video signals, for example, about three lines (32 Mbl)sX, and the management station 7 manages the allocation of these lines.

A specific example of the line may be one based on a time division multiplexing method in which frames of a predetermined format are circulated around a loop-shaped transmission path.

FIG. 2(a) is an example of such a frame.

The frame shown in the figure has a frame length of, for example, 125μ.
It is composed of a frame header, a control bucket part, and a line part. The frame header indicates the beginning of the frame, and subsequent devices are determined based on this frame header. The control packet section is a small packet used for communication between stations, and is used for connection control and network management. The line section is composed of slots of 64 kbit each, and three 32 Mbps lines are prepared in a part of the slot.

The management station 7 manages the above-mentioned line allocation and controls the transmission of video signals from the camera 2. The content of this is that the usage status of each line and the usage status of the camera 2 are known in advance using a management table, etc., and when the camera 2 that should be displayed is specified from the monitor 4, an idle line is displayed on the monitor 4. At the same time, the specified camera 2 is controlled to transmit a video signal through the available line.

The monitor 4 has a function of requesting the management station 7 to designate the camera 2 that should display the above-mentioned information.

Further, it is possible to receive video signals from any line, and after making the above-mentioned request, a state is reached in which the line designated by the management station 7 is received. That is, the monitor 4 can use any line and predetermined camera 2 under the control of the management station 7.

“Camera 2 is located at the designated l1i under the control of management station 7.
Sends a video signal to lilfj&.

The above-described communication between the camera 2, monitor 4, and management station 7 is performed using, for example, a control packet.

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

It is assumed here that the camera 2a is photographing important images that need to be displayed on all monitors 4, and the cameras 2b and subsequent cameras are photographing images that can be displayed as needed.

First, a case in which broadcast video is displayed will be described.

As a result of inquiring the management station 7, each monitor 4a, 4b, .

Therefore, each monitor 4a, 4b, . . . can display the image of the camera 2a at any time by selecting the first line as necessary.

Next, a case will be described in which an arbitrary monitor displays an image from an arbitrary camera.

Here, a case will be described in which the monitor 4b displays the image of the camera 2b.

First, the monitor 4b requests the management station 7 to display the image of the camera 2b.

The management station 7 connects the monitor 4b to an idle line (here, the second
line. ) and controls the camera 2b to transmit a video signal via the second line.

Camera 2b transmits a video signal to the second line.

The monitor 4b can display the image of the camera 2b by selecting the second line.

As described above, according to the present system, switching and broadcasting of video signals can be easily performed. That is, if it is possible to transmit video signals from any camera to any monitor based on instructions from the management station, as in the present system, it becomes possible to easily switch video signals. In addition, camera images include not only images that can be displayed by switching, but also images that must be constantly displayed on the monitor of the management station. Furthermore, if there are multiple management stations,
You need to distribute video to multiple monitors.

Therefore, if a video signal is transmitted over a transmission path and received by multiple monitors as in this system, the same video can be displayed on multiple monitors.

Furthermore, according to this system, it is possible to add a camera or change its position by laying a cable from the camera to the nearest station. That is, the cost of laying cables required to transmit video signals can be reduced. Taking ITV for expressway monitoring as an example, optical cables can be laid along the expressway to form a loop-shaped transmission path, and cameras can be housed in the nearest stage engine.

If there is a configuration change such as the addition of a camera, just add it to the nearest station.

Embodiment of the invention as claimed in claim 2 FIG. 3 is a diagram showing the configuration of a video exchange system according to an embodiment of the invention as claimed in claim 2.

As shown in the figure, a plurality of cameras 2, 2... and a plurality of monitors 4, 4... are each connected to a station (not shown) that can interface with them, and these stations are connected in a loop via an optical cable 5.

That is, a plurality of cameras 2a, 2b... and a plurality of monitors 4
a, 4b, . . . are connected in a loop through a station and a transmission line called an optical cable 5.

The loop-shaped transmission path is provided with a plurality of lines capable of transmitting video signals, for example, about 30 lines of 1.5 Mbps.

As a specific example of the line, a time-division multiple gravity system in which frames of a predetermined format are circulated around a loop-shaped transmission path can be considered.

FIG. 2(a) is an example of such a frame.

The frame shown in the figure has a frame length of, for example, 125 μs.
It consists of a frame header, a control packet part, and a line part. The frame header indicates the beginning of the frame, and subsequent positions are determined based on this frame header. The control bucket section is a small packet used for communication between stations, and is used for connection control and network management. The line part consists of slots of 64 kblv, and some of them have 1.5 Mbps
There are 30 lines available.

Each of these 30 lines has 30 cameras2.
is fixedly assigned. That is, each camera 2 has its own line.

The monitor 4 is capable of receiving video signals from any line.

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

It is assumed here that the camera 2a is photographing important images that need to be displayed on all monitors 4, and the cameras 2b and subsequent cameras are photographing images that can be displayed as necessary.

First, a case in which broadcast video is displayed will be described.

Each monitor 4a, 4b, . . . knows in advance that the video signal of the camera 2a is transmitted to, for example, the first line.

Therefore, each monitor 4a, 4b, . . . can display the image of the camera 2a at any time by selecting the first line as necessary.

Next, a case will be described in which an arbitrary monitor displays an image from an arbitrary camera.

Here, a case will be described in which the monitor 4b displays the image of the camera 2b.

The monitor 4b knows in advance that the video signal of the camera 2b is being transmitted to, for example, the second line. Therefore,
The monitor 4b can display the image of the camera 2b by selecting the second line.

As described above, according to the present system, not only the effects of the embodiment corresponding to claim 1 are achieved, but also control is extremely simple, and a management station, control packets, etc. are not required.

Embodiment of the invention as claimed in claim 3 FIG. 3 is a diagram showing the configuration of a video exchange system according to an embodiment of the invention as claimed in claim 3.

As shown in the figure, a plurality of cameras 2, 2... and a plurality of monitors 4, 4... are each connected to a station (not shown) that can interface with them, and these stages The cables are connected in a loop via an optical cable 5.

That is, a plurality of cameras 2a, 2b, . . . and a plurality of monitors 4a, 4b, . . . are connected in a loop through a station and a transmission path called an optical cable 5.

The loop-shaped transmission path is provided with a plurality of lines capable of transmitting video signals, for example, about 30 lines of 1.5 Mbps.

A specific example of the line may be one based on a time division multiplexing method in which frames of a predetermined format are circulated around a loop-shaped transmission path.

Figure 3fi2 (a) is an example of such a frame.

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 line part. The frame header indicates the beginning of the frame, and subsequent positions are determined based on this frame header. The control bucket section is a small packet used for communication between stations, and is used for connection control and network management. The line section consists of slots of 84 kbH, and 30 1.5 Mbps lines are provided in some of them.

A monitor 4 is fixedly assigned to each of these 30 lines. That is, each monitor 4 has its own line.

The camera 2 is capable of transmitting video signals to either line.

Note that communication between the camera 2 and the monitor 4 is performed using, for example, a control bucket.

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

It is assumed here that the camera 2a is photographing important images that need to be displayed on all monitors 4, and the cameras 2b and subsequent cameras are photographing images that can be displayed as necessary.

First, a case in which broadcast video is displayed will be described.

Each monitor 4a, 4b, . . . requests the camera 2a to transmit a video signal of its own line using a control packet. Camera 2a starts transmitting a video signal to the requested line.

Therefore, each monitor 4a, 4b, . . . can display the image of the camera 2a at any time.

Next, a case will be described in which an arbitrary monitor displays an image from an arbitrary camera.

Here, a case will be described in which the monitor 4b displays the image of the camera 2b.

The monitor 4b requests the camera 2b to transmit the video signal of its own line using a control packet.

Camera 2b starts transmitting a video signal to the requested line. Therefore, the monitor 4b can display the image from the camera 2b.

At this time, the monitor 4C can display the image of the camera 2b by asking the camera 2b to tell it the line number to be used and selectively receiving the line of the monitor 4b.

As described above, according to the present system, not only the effects of the above-mentioned embodiments are achieved, but also the control is very simple t1i, and no management station is required.

Also, when comparing the number of cameras and monitors, there are usually more cameras (and it seems more likely that cameras will be selected and received on the monitor. Therefore, the characteristics of this system are as follows: Even with the same fixed allocation method, it seems that fewer lines are required compared to a system that fixedly allocates lines to cameras.

Embodiment of the invention set forth in claim 4 FIG. 3 is a diagram showing the configuration of a video exchange system according to an embodiment of the invention set forth in claim 42.

As shown in the figure, a plurality of cameras 2.2... and a plurality of monitors 4.4... are each connected to a station (not shown) that can interface with them, and these stations are connected in a loop via an optical cable 5.

That is, a plurality of cameras 2a, 2b... and a plurality of monitors 4
a, 4b, . . . are connected in a loop through a station and a transmission line called an optical cable 5.

The loop-shaped transmission path includes a plurality of lines capable of transmitting video signals, for example, 1. About 30 s MbpsX are available.

A specific example of the line may be one based on a time division multiplexing method in which frames of a predetermined format are circulated around a loop-shaped transmission line.

FIG. 2(a) is an example of such a frame.

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 line part. The frame header indicates the beginning of the frame, and the positions after j are determined based on this frame header. The control bucket section is a small bucket used for communication between stations, and is used for connection control and network management. The line section consists of slots of 4kbit each, some of which have 1.5Mb slots.
There are 30 PS lines available.

A monitor 4 is fixedly assigned to each of these 30 lines. That is, each monitor 4 has its own line. Furthermore, one of the 30 lines is allocated to be shared by all the cameras 2 and the monitors 4.

The camera 2 is capable of transmitting video signals to any line.

Note that communication between the camera 2 and the monitor 4 is performed using, for example, control packets.

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

It is assumed here that the camera 2a is photographing important images that need to be displayed on all monitors 4, and the cameras 2b and subsequent cameras are photographing images that can be displayed as needed.

First, a case in which broadcast video is displayed will be described.

A video signal related to a broadcast image transmitted from the camera 2a is transmitted to a line allocated to be shared by all the cameras 2 and the monitors 4.

Therefore, each monitor 4a, 4b, . . . can display the image of the camera 2a at any time by selecting this shared line.

Next, a case will be described in which an arbitrary monitor displays an image from an arbitrary camera.

Here, a case will be described in which the monitor 4b displays the image of the camera 2b.

The monitor 4b requests the camera 2b to transmit the video signal of its own line using a control packet.

Camera 2b starts transmitting a video signal to the requested line. Therefore, the monitor 4b can display the image from the camera 2b.

At this time, the monitor 4C can display the image of the camera 2b by asking the camera 2b to tell it the line number to be used and selectively receiving the line of the monitor 4b.

As described above, the present system not only provides the effects of the embodiments described above, but also has very simple control and does not require a management station.

Furthermore, when comparing the number of cameras and monitors, there are usually more cameras, and it is thought that reception is more likely to be performed by selecting a camera on the monitor. Therefore, a feature of this system is that even with the same fixed allocation method, the number of lines required is thought to be smaller than that of a system in which lines are fixedly allocated to cameras. Furthermore, since the control of this system is performed in a distributed manner, it can be said that the system is robust against failures.

FIG. 3 is a diagram showing the configuration of a video exchange system according to an embodiment of the invention as set forth in claim 5.

As shown in the figure, a plurality of cameras 2, 2... and a plurality of monitors 4, 4... are each connected to a station (not shown) that can interface with them, and these stages The cables are connected in a loop via an optical cable 5.

That is, a plurality of cameras 2a, 2b... and a plurality of monitors 4
a, 4b, . . . are connected in a loop through a station and a transmission line called an optical cable 5.

The loop-shaped transmission path is provided with about 30 lines of order, for example, 1.5 Mbps x which can transmit video signals.

A specific example of the line may be one based on a time division multiplexing method in which frames of a predetermined format are circulated around a loop-shaped transmission line.

FIG. 2(b) is an example of such a frame.

The frame shown in the figure has a frame length of, for example, 125 μs.
It consists of a frame header, an inch node, a control bucket section, and a line section. The frame header indicates the beginning of the frame, and subsequent positions are determined based on this frame header. ? The b1r8 bucket section is used for communication between stations in small packets, and is used for connection control and network management. The index is used to recognize an index frame indicating the beginning of multiple frames on the transmission path. That is,
If the total length of the transmission line is short, only one frame 1/-me will be placed on it, but if the total length is long, there is a possibility that a plurality of frames will be placed on it. Therefore, for example, a frame with an index of "1" means the first frame, and a frame with an index of "10" means a frame other than the first frame.

The line section is composed of slots of 84 kbit each, and 30 1.5 Mbps lines are prepared in one part.

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

It is assumed here that the camera 2a is photographing important images that need to be displayed on all monitors 4, and the camera 2b and subsequent cameras are photographing images that can be displayed as needed.

First, a case in which broadcast video is displayed will be described.

The monitor 4 that should receive the broadcast video uses a control packet to inquire about the line number of the camera 2a that is photographing the video, and learns the line.

Therefore, each monitor 4a, 4b, . . . can display a broadcast image on the monitor by selectively receiving a video signal from that line.

Next, a case will be described in which an arbitrary monitor displays an image from an arbitrary camera.

Here, a case will be described in which the monitor 4b displays the image of the camera 2b.

The monitor 4b uses a control packet to request the camera 2b to transmit a video signal.

When the camera 2b is requested to transmit a video signal from the monitor 4b, it searches for an empty line on the index frame,
If found, a video signal is sent to this line and the line is secured at the same time.

Since there is only one index frame on the transmission line, multiple cameras will not start using that line at the same time.

The camera 2b notifies the monitor 4b of the line section using a control packet.

The monitor 4b can display a desired image on the monitor by selectively receiving video signals from the line.

As described above, the present system not only provides the effects of the embodiments described above, but also has very simple control and does not require a management station.

In addition, there is no need to prepare special slots on the frame, and since the display when the line is in use uses the video signal itself, there is no need to prepare anything special, and there is an advantage that the number of lines can be small. .

Furthermore, since the Lm m of this system is performed in a distributed manner, it can be said that the system is robust against failures.

FIG. 3 is a diagram showing the configuration of a video exchange system according to an embodiment of the invention as claimed in claim 6.

As shown in the figure, a plurality of cameras 2.2... and a plurality of monitors 4.4... are each connected to a station (not shown) that can interface with them, and these stations are connected in a loop via an optical cable 5.

That is, a plurality of cameras 2a, 2b... and a plurality of monitors 4
a, 4b, . . . are connected in a loop through a station and a transmission line called an optical cable 5.

The loop-shaped transmission line has multiple four-wires that can transmit video signals, for example! , about 30 5 MbpsX are available.

A specific example of the line may be one based on a time division multiplexing method in which frames of a predetermined format are circulated around a loop-shaped transmission line.

FIG. 2(C) is an example of such a frame.

The frame shown in the figure has a frame length of, for example, 125 μs.
It consists of a frame header, an index, a declaration slot, a control bucket part, and a line part. The frame header indicates the beginning of the frame, and subsequent positions are determined based on this frame header. The control bucket section is a small packet used for communication between stations, and is used for connection control and network management. The index is used to recognize an index frame indicating the beginning of multiple frames on the transmission path.

That is, if the total length of the transmission path is short, only one frame will be placed on it, but if the total length is long, there is a possibility that a plurality of frames will be placed on it. Therefore, for example, a frame with an index of 1'' means the first frame, and a frame with an index of 0° means a frame other than the first frame.The dialect slot is the only one that exists on a frame on the transmission path. Yes, the monitor 4 enters the line part in this slot to declare the line to be used and sends it.The line part is
It consists of 64kBL slots, some of which have 30 1.5Mbps lines.

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

It is assumed here that the camera 2a is photographing important images that need to be displayed on all monitors 4, and the cameras 2b and subsequent cameras are photographing images that can be displayed as necessary.

First, a case in which broadcast video is displayed will be described.

The monitor 4 that is to receive the broadcast video receives the line number from the camera 2a that is transmitting the video signal related to the video using a control packet, and selects and receives the line to receive the video. can be displayed. The same process can be performed for other monitors 4 as well.

Next, a case will be described in which an arbitrary monitor displays an image from an arbitrary camera.

Here, a case will be described in which the monitor 4b displays the image of the camera 2b.

The monitor 4b searches for an empty line among the video signal lines.

When found, the declaration slot on the index frame, which is the only one on the transmission path, is used to declare that the line is exclusive.

Since there is only one index frame on the transmission line, multiple monitors will not start using the line at the same time.

The monitor 4b sends a request to transfer the line and video signal to the camera 2b.

In response, camera 2b sends a video signal to that line.

The monitor 4b can display a desired image on the monitor by selectively receiving video signals from the line.

As described above, the present system not only provides the effects of the embodiments described above, but also has very simple control and does not require a management station.

Another advantage is that the number of lines may be small.

Furthermore, since the control of this system is performed in a distributed manner, it can be said that the system is robust against failures.

FIG. 3 is a diagram showing the configuration of a video exchange system according to an embodiment of the invention set forth in claim 7.

As shown in the figure, a plurality of cameras 2, 2... and a plurality of monitors 4, 4... are each connected to a station (not shown) that can interface with them, and these stations are connected in a loop via an optical cable 5.

That is, a plurality of cameras 2a, 2b... and a plurality of monitors 4
a, 4b, . . . are connected in a loop through a station and a transmission line called an optical cable 5.

The loop-shaped transmission path is provided with a plurality of lines capable of transmitting video signals, for example, about 30 lines of 1.5 Mbps.

A specific example of the line may be one based on a time division multiplexing method in which frames of a predetermined format are circulated around a loop-shaped transmission line.

FIG. 2(C) is an example of such a frame.

The frame shown in the figure has a frame length of, for example, 125 μs.
It consists of a frame header, an index, a declaration slot, a control bucket part, and a line part. The frame header indicates the beginning of the frame, and subsequent positions are determined based on this frame header. $i18
The bucket section is used for communication between stations in small packets, and is used for 1' connection control and network management. The index is used to recognize an index frame indicating the beginning of a plurality of frames on the transmission path. That is, if the total length of the transmission path is short, only one frame will be placed on it, but if the total length is long, there is a possibility that a plurality of frames will be placed on it. So, for example, a frame with index '11' means the first frame, '0°
The frame is assumed to mean a frame other than the first frame. The declaration slot is the only slot that exists on the frame on the transmission path, and is used by the monitor 4 to declare the line to be used, and the line part is written in this part and transmitted. The line section is composed of slots of 84 kbit each, and 30 1.5 Mbps lines are prepared in one part.

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

It is assumed here that the camera 2a is photographing important images that need to be displayed on all monitors 4, and the cameras 2b and subsequent cameras are photographing images that can be displayed as needed.

First, a case in which broadcast video is displayed will be described.

The monitor 4 that should receive the broadcast video uses a control packet to inquire of the line number of the camera 2a that is shooting the video, and displays the broadcast video on the monitor by selectively receiving the video signal from that line. be able to.

The same process can be performed for other monitors 4 as well.

Next, a case will be described in which an arbitrary monitor displays an image from an arbitrary camera.

Here, a case will be described in which the monitor 4b displays the image of the camera 2b.

The monitor 4b requests the camera 2b to transmit a video signal.

The camera 2b searches for an empty line on which no video signal is flowing from among the lines for video signals.

When found, the declaration slot on the index frame, which is the only one on the transmission path, is used to declare that the line is exclusive.

Since there is only one index frame on the transmission line, multiple monitors will not start using the line at the same time.

The camera 2b not only informs the monitor 4b of the line name but also transmits a video signal to the line.

The monitor 4b can display a desired image on the monitor by selectively receiving video signals from the line.

As described above, the present system not only provides the effects of the embodiments described above, but also has very simple control and does not require a management station.

Another advantage is that the number of lines may be small.

Furthermore, since the control of this system is performed in a distributed manner, it can be said that the system is robust against failures.

[Effects of the Invention] As explained above, according to the present invention, it is possible to reduce the cost of laying cables necessary for transmitting video signals, and furthermore, it is possible to easily switch and broadcast video signals. Can be done.

In other words, it is possible to realize a video exchange system that can flexibly deal with changes, expansions, etc. of the system.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a video exchange system according to an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of a frame used in the embodiment of the present invention, and FIG. A diagram showing the configuration of a video exchange system according to an embodiment, and FIGS. 4 to 6 are diagrams showing the configuration of a conventional video exchange system. 2.2...,...camera, 4,4...,...monitor, 5...optical cable, 7...management station. Figure 1 Applicant: Toshiba Corporation

Claims (7)

[Claims] (1) In a video exchange system configured such that one or more monitors receive video signals transmitted from a plurality of cameras and display the images, the cameras, the monitors, and the management station The monitor is connected in a loop through a transmission line having a signal line, and the management station has a function of managing the allocation of the line and controlling the transmission of the video signal in the camera, and the monitor is connected to the management station. When a camera to be displayed is specified, the management station allocates a predetermined line to the monitor and controls the specified camera to transmit a video signal through the allocated line. video exchange system. (2) In a video exchange system configured such that one or more monitors receive video signals transmitted from a plurality of cameras and display the images, the cameras and the monitors They are connected in a loop through a transmission path having a line, and a unique line for the video signal is assigned to each camera, and when there is a camera to be displayed by the monitor, the video signal corresponding to the camera is connected to the camera. A video switching system characterized by selecting lines for unique video signals. (3) In a video exchange system configured to receive video signals transmitted from a plurality of cameras by one or more monitors and display the images, the camera and the monitor are configured to receive video signals transmitted from a plurality of cameras, respectively, and display the video signals. They are connected in a loop through a transmission path having a line, and a unique line for the video signal is assigned to each monitor, and when there is a camera that the monitor should display, the line is assigned to that camera. A video switching system characterized in that the transmission of a video signal is instructed to the line for the unique video signal. (4) In a video exchange system configured such that one or more monitors receive video signals transmitted from a plurality of cameras and display the images, the cameras and the monitors The monitors are connected in a loop through a transmission path having a line, each monitor is assigned a unique line for the video signal, and at least one line for the video signal is shared by all the cameras and monitors. line is allocated, and if there is a camera that should be displayed on multiple monitors, the camera is made to transmit a video signal to the shared video signal line, and the camera that should be displayed individually on the monitor is 1. A video switching system characterized in that, at certain times, an instruction is given to transmit a video signal to the specific video signal line assigned to the camera. (5) In a video exchange system configured such that one or more monitors receive video signals transmitted from a plurality of cameras and display the images, the cameras and the monitors The monitor is connected in a loop through a transmission path having a line, and a predetermined frame including the line for the video signal is circulated on the transmission path. Make a request to send a signal,
A video switching system characterized in that a camera that receives this request searches for an empty line on the frame and transmits a video signal using the found empty line. (6) In a video exchange system configured to receive video signals transmitted from a plurality of cameras on one or more monitors and display the images, the camera and the monitor are configured to receive video signals transmitted from a plurality of cameras, respectively, and to display the images thereof, wherein the camera and the monitor A predetermined frame including a line for the video signal is circulated on the transmission path, and when there is a camera to be displayed on the monitor, the line for the video signal is connected in a loop through a transmission path having a line. Search for an empty line among the lines, and when found, use the only declaration slot existing on the frame on the transmission path to declare that the line is exclusive, and use the line to the camera that should perform the display. A video exchange system characterized in that the video exchange system instructs to transmit a video signal. (7) In a video exchange system configured such that one or more monitors receive video signals transmitted from a plurality of cameras and display the images, the camera and the monitor are configured to The monitor is connected in a loop through a transmission line having a line, and a predetermined frame including the line for the video signal is circulated on the transmission line, and when there is a camera to be displayed by the monitor, the frame is sent to the camera. The camera that makes the request and receives the transmission request searches for an empty line among the lines for the video signal, and when it finds one, uses the only declaration slot existing on the frame on the transmission path to exclusively use the line. A video switching system characterized in that the video switching system notifies the monitor that issued the transmission request of the line name and transmits a video signal to the line.