JPH06165186A - Bus line network type video communication system - Google Patents

Abstract

PURPOSE:To obtain a bus line network type video communication system capable of increasing the number of monitoring cameras without undergoing restriction of a conducting switching mechanism of a managing device such as a concentrated monitoring device, easily connecting a monitoring camera or the concentrated monitoring device on an optional point on a bus line and dealing with much more communication by executing high speed communication. CONSTITUTION:Monitoring cameras C31 to C40 and a concentrated monitoring device 50 are connected to the bus line 40. A desired camera is specified from the device 50 and a request instruction for requesting an image is transmitted. The request instruction is made into a packet and fetched in only the specified camera through the bus line 40. Packet made video data are returned from the camera fetching the instruction in accordance with the instruction. The received video data are displayed on a monitor TV.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bus line network type video communication system, and more particularly to a structure in which a surveillance camera or the like has high expandability and which facilitates connection between the surveillance camera and the surveillance device.

[0002]

2. Description of the Related Art Conventionally, in a system for monitoring images from factories, etc. (centralized monitoring by monitoring cameras), monitoring cameras are provided at a plurality of places in the factory, and the images from each monitoring camera are centrally managed in one place. Was there. Therefore, the wiring from each surveillance camera is temporarily collected in the centralized monitoring device. That is, each surveillance camera and the centralized surveillance device were directly connected individually. The place to be monitored is selected by a selection switch of the centralized monitoring device and displayed on the screen of the monitor TV.

FIG. 5 shows an example of the configuration of a communication network for surveillance cameras in factories and the like. This communication network is composed of a centralized monitoring device 20 and monitoring cameras C1, C2, C3, C4 and C5. And these are the cables L
They are connected by 1, L2, L3, L4 and L5. The centralized monitoring device 20 is provided with a selection switch 22 and three monitor TVs 25.

Surveillance cameras C1, C2, C3, C4 and C
5 video signals are cables L1, L2, L3, L4 and L
It is once sent to the centralized monitoring device 20 via 5. Then, the video signal taken in by the centralized monitoring device 20 is displayed on the monitor TV 25 through the following selection operation.

Now, the monitor TV C25, the monitor camera C1,
It is assumed that the images of C2 and C3 are projected. Here, when the supervisor of the centralized monitoring device 20 monitors the state of the installation locations of the monitoring cameras C4 and C5, first,
The monitor turns off the operation switches 22 corresponding to the monitoring cameras C1, C2, and C3. That is, these conductive states are cut off, and the image on the monitor TV 25 is once erased.

Then, the operation switch 22 corresponding to the surveillance cameras C4 and C5 is pressed to specify a new image to be captured. As a result, the surveillance cameras C4 and C5 and the monitor TV are brought into conduction. Then, the images taken by the monitoring cameras C4 and C5 are displayed on the monitor TV. That is, by operating the selection switch 22, the video of the desired surveillance camera is displayed on the monitor TV 25.

[0007]

However, the conventional communication network of surveillance cameras has the following problems.
When displaying the video of the desired surveillance camera on the monitor TV, the supervisor first selects the operation switch 22. By this operation, the centralized monitoring device 20 switches the conduction state between the monitor TV 25 and the surveillance camera to display the specified image on the monitor TV. Therefore, there is a problem that it is not possible to add more surveillance cameras than the number of switching mechanisms provided in the centralized monitoring device 20.

Further, as shown in FIG. 5, the monitoring cameras C1 to C5 are individually connected via the cables L1 to L5 to send respective images to the centralized monitoring device 20. Therefore, there is a problem that the wiring becomes complicated.

Therefore, the present invention allows the number of surveillance cameras to be increased without being restricted by the conduction switching mechanism of the management apparatus such as the centralized surveillance apparatus, and further, the surveillance cameras and the centralized surveillance apparatus can be arranged at arbitrary points on the bus line. It is an object of the present invention to provide a bus line network type video communication system that can easily connect to each other and can process more communication by performing high speed communication.

[0010]

In a video input terminal according to a first aspect of the present invention, a video converting means for converting an image into a video signal, an analog / digital converting means for converting a video signal into a digital signal, and a digital signal are stored. Digital signal storage means, command discrimination means for discriminating whether or not the received request instruction is for itself, and when the instruction is discriminated for itself, the digital signal stored in the digital signal storage means is transmitted. It is characterized by comprising a communication control means for performing.

In the video reproducing terminal according to claim 2,
Terminal selecting means for selecting an arbitrary video input terminal, command sending means for sending a request command requesting a digital signal to the video input terminal selected by the terminal selecting means, and taking in a digital signal sent from the video input terminal, A digital / analog conversion means for converting a digital signal into a video signal, and a reproduction means for reproducing the video signal as an image are provided.

In the bus line network type video communication system according to claim 3, bus line network means to which the video input terminal of claim 1 and the video reproduction terminal of claim 2 are connected, wherein the video input terminal is A plurality of video reproduction terminals are provided with one or more bus line network means connected thereto. A bus line network type video communication system according to claim 4 is the bus line network type video communication system according to claim 3, wherein when a plurality of communications are performed on the bus line network means, the digital signal is time-divided. It is characterized by communicating.

[0013]

In the bus line network type video communication system according to the first aspect, the second aspect and the third aspect, the video input terminal converts the video into a video signal and then converts the video signal into a digital signal, and the digital signal storage means Remember. The video reproduction terminal selects an arbitrary video input terminal and sends a request command requesting a digital signal. When the video input terminal determines that the request command is its own, it sends a digital signal. The bus line network means carries request commands and digital signals exchanged between the video input terminal and the video reproduction terminal. The video reproduction terminal converts the captured digital signal into a video signal and reproduces it as a video.

Therefore, the video reproduction terminal selects which video input terminal to send the request command to, and after selecting, takes in a digital signal from the video input terminal. That is, it is not necessary to electrically switch the connection when reproducing a large number of videos.

The video input terminal and the video reproduction terminal are connected by bus line network means. For this reason,
A video input terminal or a video reproduction terminal can be connected to any point on the line.

In the bus line network type video communication system according to the fourth aspect, when a plurality of communications are carried out on the bus line network means, the digital signal is time-divisionally communicated.

Therefore, high-speed communication is possible by time division, and the use efficiency of the bus line network means is improved.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bus line network type video communication system according to the present invention will be described with reference to the drawings. In this embodiment, a monitor system using images of a factory or the like will be described as an example. FIG. 1 is a block diagram showing the configuration of the bus line network type video communication system. Here, one of the surveillance cameras C31, C32, ...
0 cameras are connected to a bus line 40 which is a bus line network means. A centralized monitoring device 50 as a video reproduction terminal is also connected to the bus line 40. That is, the ten monitoring cameras are connected to the centralized monitoring device 50 via the bus line 40. The centralized monitoring apparatus 50 is provided with three monitor TVs 55 as reproducing means and operation switches 52 as terminal selecting means.

FIG. 3 shows the structure of the surveillance camera C40. A camera signal circuit 67 for converting a video signal into a video signal is connected to an A / D converter 66 which is an analog / digital conversion means. The CPU 61, the ROM 62, and the RAM 63, which is a digital signal storage unit, are connected to the internal bus line 60 and control each unit. A network controller 64 is provided as communication control means, and the driver 65 is connected to the bus line 40.

FIG. 2 shows a block diagram of the centralized monitoring device 50. The monitor TV 55 as a reproducing means is connected to the D / A converter 53 which is a digital / analog converting means. The CPU 41, the ROM 42, and the RAM 43 are connected to the internal bus line 30 and control each unit. Further, an operation switch 52 as a command transmitting means is provided,
Further, a driver 45 is connected to the bus line 40 via the network controller 44.

The operation of the centralized monitoring system will be described below with reference to FIGS. 1, 2 and 3. Images captured by the ten monitoring cameras C31 to C40 installed at various places in the factory are converted into video signals (analog signals) by the camera signal circuit 67 (see FIG. 3). And
This analog signal is converted into a video signal (digital signal) by the A / D converter 66. Here, the CPU 61 sequentially stores the converted video signal in the RAM 63 in accordance with the program stored in the ROM 42. Such video capturing and storage operations are performed by all surveillance cameras.

On the other hand, the surveillance staff selects the surveillance camera to be monitored from the 10 surveillance cameras. In this embodiment, since three monitor TVs 55 are provided (see FIG. 1), three surveillance cameras are selected. Then, the operation switch 52 of the centralized monitoring device 50 is pressed to specify, for example, the monitoring cameras C31, C32, C40. Then, the network controller 44 connected to the operation switch 52 sends a request command to these three surveillance cameras. Request command is surveillance camera C31, C32, C
A signal specifying 40 is included. The request command is packet data obtained by dividing a digital signal into a certain length. The request command which is packet data is transmitted from the network controller 44 to the bus line 40 through the driver 45 (see FIG. 2).

The request signal transmitted to the bus line 40 is temporarily sent to all the monitoring cameras (monitoring cameras C31 to C4).
0) is input to the network controller. However, since the request command includes the signals designating the surveillance cameras C31, C32, and C40, the surveillance camera other than these requests is blocked without being captured (see FIG. 1).

Here, the surveillance cameras C31, C32, C4
For the order of sending the request signal to 0, the central monitoring device 5
The network controller 44 of 0 judges and controls. Therefore, each request instruction does not interfere on the bus line.

The request command fetched by the surveillance cameras C31, C32, C40 is fetched by the CPU 61 from the network controller 64. Then, the CPU 61, which recognizes the request command, extracts the video signal stored in the RAM 63. The video signal (digital signal) extracted from the RAM 63 is output to the bus line 40 via the network controller 64. At this time, the network controller 64 packetizes the extracted video signal (digital signal) and transmits it (see FIG. 3).

The packetized video signal (packet video signal) is transmitted again on the bus line 40 and taken into the centralized monitoring device 50. Surveillance cameras C31, C32, C4
The network controller of each surveillance camera also determines the timing of transmitting the packet video signal from 0 to the centralized surveillance device 50. Therefore, the packet video signal also does not cause interference on the bus line 40. Further, since the packet video signal is carried on the bus line 40 in a time division manner and at a high speed, the monitor can monitor an uninterrupted video.

The packet video signal taken in is the original video signal (digital signal) by the network controller 44.
Is converted to. And the converted digital signal is CP
It is sent to the D / A converter 53 under the control of U41. This video signal (digital signal) is converted into a video signal (analog signal) by the D / A converter 53. The video signal (analog signal) is displayed on the monitor TV 55 as an image of each place in the factory and is monitored by a monitor (see FIG. 2).

The state of the packet data carried on the bus line 40 is shown in FIG. The time axis is now indicated by arrow 80. Here, first, packet data D1 which is a packet video signal is transmitted from the monitoring camera C31 to the centralized monitoring device 50. Next, the packet data D2 as a request command from the centralized monitoring device 50 to the monitoring camera C40, the packet data D3 as another request command, and the packet video signal D4 are also carried. At this time, bus line 4
On 0, the packet data D1 to D4 are conveyed at high speed.

Therefore, the request command and the packet video signal can be exchanged between the centralized monitoring device 50 and the monitoring cameras C31 to C40 almost at the same time. For example, in the centralized monitoring device 50, the monitoring camera C31
It is also possible to send a request command to the monitoring camera C40 while capturing the image from. That is, bidirectional communication can be performed on the bus line 40 and a large amount of communication can be performed by temporally shortening the request command and the video data.

In this embodiment, the request command and the video data are carried by PCM data (pulse code modulation) which is converted from analog to digital, but the video data is compressed and carried in order to increase the data carrying speed. You may.

Further, in the present embodiment, the case where the centralized monitoring device 50 is one has been described, but a plurality of centralized monitoring devices may be provided.

[0032]

In the bus line network type video communication system according to claim 1, claim 2 and claim 3, the video reproducing terminal selects and selects to which video input terminal the request command is transmitted. After that, the digital signal is taken in from the video input terminal. That is, it is not necessary to electrically switch the connection when reproducing a large number of videos.

The video input terminal and the video reproduction terminal are connected by bus line network means. For this reason,
A video input terminal or a video reproduction terminal can be connected to any point on the line. Therefore, the video input terminal or the video reproduction terminal can be connected to any point on the line. Therefore, it is possible to avoid complicated wiring and facilitate connection. That is, it is possible to connect without any restriction on the installation position or the like.

In the bus line network type video communication system according to the fourth aspect, high speed communication is possible by time division, and the use efficiency of the bus line network means is improved. Therefore, it becomes possible to process more communication.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a bus line network type video communication system according to the present invention.

FIG. 2 is a block diagram of the centralized monitoring device shown in FIG.

3 is a block diagram of the surveillance camera shown in FIG. 1. FIG.

FIG. 4 is a diagram showing a data carrying state on a bus line of the bus line network type video communication system shown in FIG. 1.

FIG. 5 is a block diagram showing a conventional centralized surveillance system using surveillance cameras.

[Explanation of Codes] C31, C32 ... C40 ... Surveillance camera 40 ... Bus line network 50 ... Centralized monitoring device 52 ... Operation switch 55 ... Monitor TV

Claims (4)

[Claims] 1. A video conversion means for converting an image into a video signal, an analog / digital conversion means for converting a video signal into a digital signal, a digital signal storage means for storing a digital signal, and a request command received for itself. A video input, comprising: an instruction determination means for determining whether or not the instruction is provided, and a communication control means for transmitting a digital signal stored in the digital signal storage means when the instruction is determined to be its own. Terminal. 2. A terminal selecting means for selecting an arbitrary video input terminal, a command sending means for sending a request command requesting a digital signal to the video input terminal selected by the terminal selecting means, A video reproducing terminal comprising: a digital / analog converting means for receiving a digital signal and converting the digital signal into a video signal; and a reproducing means for reproducing the video signal as an image. 3. A bus line network means to which the video input terminal according to claim 1 and the video reproduction terminal according to claim 2 are connected, wherein a plurality of video input terminals and one or more video reproduction terminals are connected. A bus line network type video communication system, comprising: 4. A bus line network type video communication system according to claim 3, wherein when a plurality of communications are carried out on the bus line network means, a digital signal is time-divisionally communicated. Line network type video communication system.