JPH0695680B2 - Video surveillance system and its terminal device - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a system for transmitting signals such as video, audio, and surveillance using a frequency-multiplexed multi-channel transmission line, and a control device therefor.

[Prior art]

2. Description of the Related Art Conventionally, there is a monitoring and security system in which a large number of TV cameras are installed in a large number of places in a high-rise building or the like, and a management center collectively monitors them. In this system, a video signal picked up by each TV camera is transmitted to each center through each signal line, and a control signal for controlling the angle of each TV camera is transmitted to each terminal where the TV camera is installed by each control signal line. Had been transmitted.

[Problems to be Solved by the Invention]

Therefore, the number of signal lines between the terminal and the center increases, which is a problem in terms of equipment usage and mounting. It is also possible to assign a unique channel to each TV camera, frequency-multiplex and transmit a video signal.
If there are hundreds of TV cameras installed, a band from 600MHz to 3000MHz is required, which is not realistic. Then, this invention is made in order to solve the said subject, The objective is to provide the video monitoring system and its terminal device with high implementation and utilization efficiency of a facility.

[Means for Solving the Problems]

The first aspect of the present invention relates to a transmission system, in which a center is provided with an image receiver for simultaneously displaying images of all channels transmitted from a terminal via a coaxial cable, and each terminal is provided with an image pickup device for picking up an image and an image pickup device of this image pickup device. A control means for controlling the imaging state such as imaging angle, zoom, diaphragm, etc. is provided, the center and a plurality of terminals are connected by a coaxial cable, and the coaxial cable constitutes a frequency-multiplexed multi-channel transmission line,
Multiple terminals are divided into multiple groups, multiple terminals belonging to the same group are fixedly assigned to the same channel of the transmission path, and the video captured by the imager from each terminal is centered by the channel assigned to that terminal. Sent to any one of the transmission lines
The channel is used as a control channel, and the center sends out a data block composed of address data specifying an image pickup device to be controlled by the control channel and command data giving a command for the operation of the image pickup device.
Each terminal, when the address data of the data block matches the address that identifies its own imager, according to the command data of the data block, the imaging angle of the imager, the zoom,
It is a system for controlling an image pickup state such as a diaphragm and transmitting an image picked up by its own image pickup device to a transmission line via a channel fixedly assigned to the terminal according to the command data. A second aspect of the present invention relates to a terminal device used in the above system, which includes an image pickup device for picking up an image, a modulator for modulating a carrier wave of a channel peculiar to the terminal with a video signal output from the image pickup device, and a transmission line. , A demodulator that demodulates a signal of a specific control channel of the multiple channels and outputs it as a data block, and whether or not the data block output by the demodulator includes address data that matches the address that identifies the imager When it is determined by the address determining unit and the address determining unit that the address specifying the own image pickup device and the address data match,
The control means for controlling the imaging state of the imaging device such as the imaging angle, the zoom and the aperture according to the command data of the data block output from the demodulator, and the control means are provided between the modulator and the transmission path.
It is a terminal device comprising switch means for connecting or disconnecting between the modulator and the transmission line according to the signal output by the control means.

[Action]

A plurality of image pickup devices are divided into a plurality of groups, and one channel is fixedly assigned to each group. A data block is transmitted from the center to the terminal using one control channel. Each terminal receives the data block sent from the center through the demodulator, and the address judging means judges whether or not the address data specifying the image pickup device connected to the own terminal is included. To do. Then, when the address data specifying the own image pickup device is included, the angle of the image pickup device, the focus adjustment, and the like are performed by the control unit according to the command data included in the data block. When the received command data includes a video signal transmission request, the video signal obtained by modulating the carrier wave of the channel fixedly assigned to the image pickup device is output to the transmission line via the switch means. It Then, the image captured by the imager is received at the center. In this way, a frequency-multiplexed multi-channel transmission line is used for the transmission line, and a plurality of image pickup devices are assigned to one channel. However, a video signal output from the image pickup device is output in response to a request from the center. Is transmitted, so there is no interference. In this way, even if a large number of image pickup devices are connected to the transmission line, they are grouped and managed, so that the whole can be monitored with a much smaller number of channels than the number of image pickup devices. Further, the video signals output by the image pickup devices belonging to different groups can be simultaneously displayed at the center, and the places monitored by the image pickup devices belonging to different groups can be simultaneously monitored. With such a system, it is possible to connect image pickup devices that are several times to several tens of times the number of channels of the transmission path.

【Example】

Hereinafter, the present invention will be described based on a specific example. FIG. 1 is a diagram showing the overall configuration of this system. In the coaxial cable 1, m terminal devices E11 to Enxn and a centralized monitoring device 2 placed in the center are respectively connected to a branch device B1.
~ Bm is connected via a coupler Bc. The coaxial cable 1 can transmit frequency-multiplexed signals of (n + 1) channels ch0 to chn. Each channel is configured at 6MHz so that the television video signal can be transmitted. One channel ch0 of the (n + 1) channels is a control channel for transmitting operation command data from the centralized monitoring device 2 to each terminal device, and the other n channels transmit a video signal from the terminal device to the centralized monitoring device 2. Is a video channel for. A large number of terminal devices are assigned to each channel.
For example, the terminal device E11～E1x ₁ to channel ch1 has, the channel ch2 is assigned the terminal unit E21~E2x _2. Although it is not possible to simultaneously watch the images output by the terminal devices assigned to the same channel, the centralized monitoring device 2
You can see them in order by scanning sequentially from. The centralized monitoring device 2 can simultaneously monitor a plurality of terminal devices assigned to different channels. The centralized monitoring device 2 outputs command data for controlling each terminal device in accordance with the operating state of the control panel 23 operated by the operator, and based on the video signal transmitted from each terminal.
C that controls the image controller 24 that displays images on the CRT 23
Has PU20. The control panel 23 is operated by an operator to remotely operate each terminal device, and includes a designated switch of the terminal device desired to receive a video signal, a power switch of the TV camera of the terminal device, a vertical switch of the TV camera and A horizontal angle adjustment stick, a lighting switch, a zoom switch, a focus adjustment switch, etc. are arranged. The operation status of the control panel 23 is CPU2 via the input / output interface 27.
Read by 0. The ROM 21 stores the operation program of the CPU 20, and the RAM 22 stores the operation state of the control panel 23 and other control states. A data block having address data and command data for controlling each terminal device is output by the CPU 20 to the RF modem 26 via the input / output interface 29. The RF modem 26 modulates the carrier wave of the control channel ch0 based on the data block, and the modulated signal is output to the control channel ch0 of the transmission line 1 via the coupler Bc. Video signals are output from the respective terminal devices to the video channels ch1 to chn of the transmission line 1. The video signal is received by the demodulator 25 of the centralized monitoring device 2, and each channel ch1 ~ c
It is demodulated for each hn and output to the image controller 24.
The image controller 24 controls the CRT 23 so that each channel c
The video imaged by each terminal device is displayed based on the video signals of h1 to chn. At this time, the image of the channel designated by the CPU 20 is displayed on the CRT 23. The channels displayed on the CRT 23 can be sequentially changed by sequentially switching the channels by the CPU 20. Further, since the CPU 20 manages which terminal device has output the video signal on the same channel, it is possible to display which terminal device the video currently displayed on the CRT 23 belongs to. Further, by controlling the CPU 20, it is possible to fix the channel and sequentially change the terminal device that outputs the video signal. Furthermore, the screen of the CRT 23 can be divided to display multiple channels at the same time. The configuration of one terminal device is shown as a representative of the terminal device Ek1 connected to the channel chk. The signal of the control channel ch0 of the transmission line 1 is encoded by the RF modem 41, and is transmitted to the CPU 40 via the input / output interface 42.
Read by The CPU 40 is connected to a ROM 43 that stores an operation program and a RAM 44 that stores a data block input from the RF modem 41. The CPU 40 also outputs a control signal to the camera control device 46 and the analog switch 47 via the input / output interface 45. The camera control device 46 turns on / off the power switch of the television camera 48 according to the received command data,
The lighting is turned on and off, the motors for vertical and horizontal angle adjustment are driven, and the focus adjustment motor and zoom motor are driven. The video signal output from the television camera 48 is input to the modulator 49. Channel chk based on that video signal to modulator 49
The carrier wave is modulated and output to the analog switch 47.
The analog switch 49 is normally in a signal passage blocking state.
Then, when the centralized monitoring device 2 requests the transmission of the video signal from the terminal device, the CPU 40 that has decoded the command data output from the centralized monitoring device 2 is brought into a signal passing state. As a result, the video signal is output from the terminal device Ek1 to the channel chk of the transmission line 1. Next, regarding the processing procedure of the CPU 20 of the centralized monitoring device 2,
It will be described with reference to the drawings. In step 100, the state of each switch for remotely operating the terminal device on the control panel 23 is read. next,
In step 102, the address data for specifying the terminal device requesting the transmission of the video signal is created from the setting data of the terminal designating switch of the control panel 23. Further, in the control panel 23, the power switch of the TV camera 48 of the terminal device is turned on / off, the vertical and horizontal angle adjusting stick operation of the TV camera is operated, the lighting switch is turned on / off, the zoom switch is turned on / off, and the focus adjustment switch is turned on / off. Command data having corresponding bits of "1" or "0" is created corresponding to the state. Next, by determining whether the CD (carrier detection) signal is output from the RF modem 26, the control channel ch0
Is determined to be empty. If it is empty, the process proceeds to step 106 and a data block including address data and command data is output to the RF modem 26. RF
When the data block is input, the modem 26 modulates the data block and then transmits the data block to the channel ch0 of the transmission path 1. Next, in step 108, the address data of the designated terminal device and the channel number data assigned to the terminal device are output to the image controller 24.
The image controller 24 uses the data to demodulate the demodulator 25.
Select the video signal of each channel output from
An image is displayed on T23 based on the video signal of the designated channel. As a result, the image captured by the designated terminal device is displayed. If the control channel ch0 is not empty in step 104, the process proceeds to step 110, waits for a certain period of time, and then returns to step 100 to repeat the same processing. Next, a processing procedure of the CPU 40 of the terminal device Ek1 will be described with reference to FIG. The RF modem 41 encodes the signal of the control channel ch0, and this program is started when the CD signal is output from the RF modem 41. In step 200, the data block encoded by the RF modem 41 is input. Next, in step 202, the address data of the data block is decoded. Next, in step 206, it is determined whether the address data matches the address assigned to the terminal device of its own. If it matches the self address, step 206
At, the command data following the address data is decoded. Then, in step 208, according to the “1” or “0” state of each bit of the received command data,
The command signal for turning on / off the power of the TV camera 48, the rotation / stop command signal for the motor for adjusting the vertical and horizontal angles of the TV camera 48, the command signal for turning on / off the illumination, the command signal for rotating / stopping the zoom motor, and the focus point. The command signal for rotating / stopping the adjustment motor is the camera control device 46.
Is output to. The camera control device 46 inputs the command signal to turn on / off the power of the TV camera 48, rotate or stop the vertical and horizontal angle adjustment motors of the TV camera 48, turn on / off the illumination, or rotate the zoom motor. Then, the focus adjustment motor is rotated or stopped. Next, in step 210, the analog switch 47 is set to the signal passing state or the signal passing blocking state according to the command data. When the video signal is requested to be sent from the terminal device Ek1, the analog switch 47 enters the signal passing state, and the television camera 48 modulated by the modulation circuit 49.
The video signal of is output to the transmission line 1 as a signal of the channel chk. As a result, the centralized monitoring device 2 can display the image captured by the designated terminal device Ek1 and can monitor the surrounding environment by the terminal device Ek1. In step 204, if the address data of the received data block is not the self address, this program is terminated without performing the following processing. Although the video monitoring system is described in the above embodiment, it can be used for multiplex transmission of voice of each terminal, monitoring by multiplex transmission of status data of each terminal, for example, machine tool, and the like. Further, the number of terminal devices connected to each channel is not particularly limited.

【The invention's effect】

The present invention divides a plurality of image pickup devices connected to a transmission line into a plurality of groups, connects a plurality of image pickup devices belonging to the same group to the same channel of the transmission line, and from a terminal to which the image pickup device is connected. Sends the video signal picked up by the image pickup device to the center through the channel assigned to the image pickup device, and uses any one channel of the transmission path as the control channel, and the center specifies the destination terminal of the data by the control channel. A data block composed of address data and command data that gives a command for the operation of the image pickup device is transmitted, and when each terminal address data of the data block matches the address that identifies its own image pickup device, that data block The imager is operated according to the command data of Since the image is sent to the channel assigned to the group to which the image pickup device belongs, it is possible to connect the image pickup device to the coaxial transmission line more than the number of channels, and it is not necessary to widen the transmission line more than necessary, The device is also easy to manufacture. Further, since the signal for controlling each terminal is also transmitted through the coaxial cable, the mounting space can be reduced and the facility utilization efficiency can be improved. Another invention is a demodulator for demodulating a signal of a control channel, and an address determining means for determining whether or not a data block output from the demodulator includes address data that matches an address for identifying its own image pickup device. When the address specifying the own imager and the address data match, the control means for controlling the operation of the imager according to the command data of the data block output from the demodulator, the modulator and the transmission line. Since the switch means which is disposed between the modulator and the transmission line is connected or disconnected according to the signal output from the control means, a plurality of switches can be provided under the control of the center without interference. The channels can be shared by the image pickup devices. Therefore, by providing this device in a terminal, it is possible to construct a video monitoring system with a high equipment utilization rate in which image pickup devices of which the number is equal to or more than the number of channels are connected.

[Brief description of drawings]

FIG. 1 is a whole system according to a specific embodiment of the present invention,
Block diagram showing the configuration of the centralized monitoring device and the terminal device,
FIG. 2 is a flowchart showing the processing procedure of the CPU of the centralized monitoring apparatus in the same embodiment, and FIG. 3 is a flowchart showing the processing procedure of the CPU of the terminal device of the same embodiment. 1 ... Transmission path, 2 ... Centralized monitoring device E11 to Enxn ... Terminal device 47 ... Analog switch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshinori Kano 3-20-6 Marunouchi, Naka-ku, Nagoya, Aichi Cast Co., Ltd. (72) Inventor Shinzo Mizuno 2-chome, Minamieki, Nakamura-ku, Nagoya, Aichi 14th to 19th Hibiya Comprehensive Equipment Co., Ltd.Nagoya Branch

Claims (2)

[Claims] 1. A center is provided with an image receiver for simultaneously displaying images of all channels transmitted from a terminal through a coaxial cable, and each terminal has an image pickup device for picking up an image, an image pickup angle of the image pickup device, and a zoom. , A control means for controlling an imaging state such as a diaphragm is provided, and the center and the plurality of terminals are connected by a coaxial cable, and the coaxial cable constitutes a frequency-multiplexed multi-channel transmission line, The terminals are divided into a plurality of groups, and a plurality of terminals belonging to the same group are fixedly assigned to the same channel of the transmission line, and the video imaged by the image pickup device is sent from each terminal to the center by the channel assigned to the terminal. Address data for sending out and using any one channel of the transmission path as a control channel, and specifying the imager to be controlled by the control channel from the center. When a data block composed of command data that gives a command for the operation of the image pickup device is sent, and each terminal matches the address data of the data block with the address that specifies its own image pickup device, the command data of the data block According to the command data, the image pickup state of the image pickup device, such as the image pickup angle, zoom, and diaphragm of the image pickup device is controlled according to the command data, and the image taken by the image pickup device of the image pickup device is fixedly assigned to the terminal via the channel. Frequency transmission system to send to. 2. An image pickup device for picking up an image, a modulator for modulating a carrier wave of a channel peculiar to a terminal by a video signal output from the image pickup device, and a specific control channel of a plurality of channels connected to a transmission line. A demodulator that demodulates the signal of to output as a data block, address determining means that determines whether or not the data block output by the demodulator includes address data that matches an address that identifies the image pickup device, When the address determining unit determines that the address specifying the own image pickup device and the address data match, the image pickup angle, zoom, and aperture of the image pickup device according to the command data of the data block output from the demodulator. Control means for controlling the image pickup state of the control unit and the signal output from the control means, which is arranged between the modulator and the transmission path. Depending on, switch means for connecting or disconnecting between said transmission line and said modulator consists, terminal device of the frequency multiplex transmission system connected to the multi-channel transmission path frequency multiplexed.