JPH0470079A - Picture monitoring device - Google Patents

Abstract

PURPOSE:To correct the deviation of the setting state of a TV camera by providing a detecting means and a state recovering means in order to get the state of the TV camera back to the state before only a delay time when a control changes uniformly from the past to the control stopping time only for the delay time being the sum of a processing time necessary for a signal process and double a signal delay time due to a transmitting path. CONSTITUTION:An image pickup device 2 is provided the control reaction 15 is equipped with the first detecting means which detects the stop of the control due to a control signal, the second detecting means which judges whether the control changes uniformly form the past to the control stopping time only for the delay time being the sum of the time required for processing a video signal and the control signal in a monitoring place and the image pickup device and double the signal delay time due to a transmitting path 13, and the state recovering means which gets the state of the TV camera back to the state before only the delay time when the control changes uniformly. Thus, the generation of the deviation of the setting state of a TV camera due to the signal delay of both a circuit and the transmitting path, can be corrected when a TV camera 9, the operating part 3, and a TV monitor 12 are arranged separately.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video monitoring device that monitors video by controlling a TV camera from a remote location.

Conventional technical video surveillance devices have been mainly used for monitoring railways, roads, etc., but in recent years, they have been put into practical use as part of crime prevention and disaster prevention systems for high-rise buildings, 24-hour stores, etc.

As for conventional video surveillance equipment, for example, the National Technical Report “ITV Surveillance Optical Transmission Equipment and Application Systems”
Vol, 33, No. 6, pp, 107-113,
DEC, 1987).

FIG. 4 shows a block diagram of this conventional video monitoring device. In the figure, 1 is a monitoring station that displays video and operates a TV camera, 2 is an imaging device on the TV camera side, and 3 4 is an operation unit for performing various controls of the TV camera;
5 is a multiplexing unit that converts the control signal from the operation unit 3 into a serial signal, and 5 is a first electrical/optical conversion unit (hereinafter referred to as the 1E10 unit) that converts the serial signal into an optical signal and transmits it.
, 6 is a first optical/electrical converter (hereinafter referred to as the 20th/E section) which converts an optical signal into an electrical signal, contrary to the first E10 section 5, and 7 converts a serial signal into a parallel control signal. 8 is a TV camera drive unit, 9 is a TV left camera 10 is a 2E10 unit that converts the video signal output from the TV left camera into an optical signal, and 11 is a converter that converts the optical signal into the original video signal. 12 is a TV monitor, 13 is an optical fiber upstream transmission line, and 14 is an optical fiber downstream transmission line.

The reason why optical fibers are used as the transmission lines 13 and 14 is because the monitoring station 1 and the imaging device 2 are far apart in terms of distance.

In this video monitoring device, TV monitor 1 is installed on the monitoring station 1 side.
While watching the video 2, operate the operation unit 3 to control the direction, iris, zoom, focus, etc. of the TV left camera.

Various control signals from the operating section 3 are converted into serial signals by the multiplexing section 4, converted into optical signals by the first E10 section 5, and sent to the upstream transmission line 13.

In the imaging device 2, the received optical signal is converted into the original serial signal by the 10th/E section 6, and further converted into the original various control signals by the demultiplexing section 7. Based on these control signals, the TV camera drive unit 8 actually controls the drive of the TV left camera.

On the other hand, the output video signal of the TV left camera is converted into an optical signal by the second E10 section 10 and sent to the downlink transmission line 4.

In the monitoring device 1, the 20th/E section converts the signal into the original electric video signal and inputs it to the TV monitor 2.

Problems to be Solved by the Invention However, in the above configuration, the TV left camera, T
Compared to the case where the V camera drive section 8, TV monitor 12, and operation section 3 are located at the same location, the multiplexing section 4, the first E10 section 5
, 10th/E part 6, multiple decomposition part 7, 2nd E10 part 10,
20th/E section 11, uplink transmission line 13, downlink transmission line 14
is in between, so a corresponding delay is added to the signal.

Therefore, even if you try to control the TV left camera to a desired state by operating the operation unit 3 while watching the image on the TV monitor 12 at the monitoring station 1 side, the setting will be set to a state that is too far from the desired state due to the above-mentioned delay. The problem was that the

In view of this, an object of the present invention is to provide a video monitoring device that can correct deviations from the desired state due to the delay.

Means for Solving the Problems The present invention provides an imaging device having a television camera (hereinafter referred to as TV left camera), and an imaging device connected to the imaging device via a transmission line and transmitting control signals for the TV camera. In a video monitoring device comprising a transmitter for transmitting data and a monitoring station having a TV monitor for receiving a TV left camera video signal, a first detection means for detecting that control by the control signal has stopped;
The control is uniform from the past until the control stop point for a delay time that is the sum of the time for processing the video signal and control signal inside the monitoring station and the imaging device, and the time twice the signal delay time due to the transmission path. a second detection means for detecting whether the control has changed uniformly during the period; and a state restoration means for returning the TV left camera state to the past state by the delay time when the control has changed uniformly during the period. The present invention is characterized in that the control unit having the control unit is provided on the imaging device side.

According to the above-described configuration, the present invention allows the TV camera control unit to process only the delay time T, which is the sum of the processing time required for the circuit to process the video signal and the control signal, and twice the signal delay time due to the transmission path. If the control has changed uniformly from the past until the control stop point, by returning the TV left camera state to the previous state by the delay time T,
Correct the deviation in the V left camera setting state.

Embodiment FIG. 1 is a block diagram of a video monitoring device according to an embodiment of the present invention. The basic configuration is the same as the conventional video surveillance device shown in FIG. 4, and employs a configuration in which the imaging device 2 and the surveillance station 1 are connected by transmission lines 13 and 14 made of optical fibers. The monitoring station 1 includes a scanning section 3, a multiplexing section 4, a first E10 section 5, a 20th/E section 11, and a TV monitor 12, like a conventional monitoring station. On the other hand, the imaging device 2 side is the same as the conventional imaging device in that it includes a 10th/E section 6, a multiplexing section 7, a TV camera drive section 8, a TV left camera, and a 2nd B10 section 10, but has the above configuration. The difference is that a control section 15 is further provided.

Although the control unit 15 is not shown, it includes a central processing unit (CPU),
A ROM that stores programs for causing this CPU to perform necessary arithmetic processing and an R for storing control signals.
It is equipped with an AM and an input/output interface, performs the processing described below using each control signal decomposed by the multiplex decomposition section 7, creates a state return signal, and supplies it to the TV camera drive section 8.

Next, the operation performed by the control section 15 will be explained using FIG. 2. This figure shows state changes in each part when controlling camera focus as an example of TV camera control. Figure (a) shows the control input on the monitoring station 1 side, and the ON state becomes a signal component that changes the focus. Figure (b)
is a control signal applied to the TV camera 8 on the imaging device 2 side. This control signal (b) is the control input ('a
) is delayed by 71 hours. This delay time τ1
are the time required to process the control input in the multiplexing section 4, the first E10 section 5, the 20th/E section 6, and the demultiplexing section 7, and the transmission delay time during which the control input is transmitted along the transmission path 13. It corresponds to the sum of the time.

Figure (c) shows the state of the camera focus changing according to the camera control signal in figure (b).

Figure (d) shows a change in the camera focus state recognized on the monitoring station 1 side. The state change in figure (d) is shown in figure (c
) is delayed by 2 hours from the state change. This delay time τ2 is the time required for processing the video signal in the second E10 unit 10, the 20th/E unit 11, and the TV monitor 12, and the transmission delay time during which the video signal is transmitted along the transmission path 14. It corresponds to the sum of the time.

Figure (e) shows a state return signal issued by the control section 15. The ON state duration time T of this signal is set to be equal to the sum of the above two delay times (τ1 +τ).

Now, at the observation station 1 side, the video is being viewed through the TV monitor 12.
- Suppose that an operator who is visually observing the waste state determines that the desired focus state x has been obtained at time t1, and operates the operation unit 3 to turn off the control input (a).

In this case, time 1. The focused Bxl recognized from the TV monitor 12 at time 1 occurred τ2 hours in the past in the TV left camera, and therefore the actual T at time 1
The focus state of the V left camera is x2, which is more advanced than xl.

Moreover, the operator has set the xl's focus state to be good and 1. Even if the control input (a) is stopped at time t2, the control input is actually input to the TV camera drive section 8 as a control signal at time t2, which is after time τ1. Therefore, the TV left camera does not stop at the focus state x2, but advances further to the focus state X.

In this way, assuming that the operator visually observes the TV monitor 12 and obtains the desired focus state x1, the control input (a)
Even if the focus state of the TV left camera is stopped, the actual focus state of the TV left camera has progressed to an undesirable x3. Note that the difference between focus states x and x3 corresponds to (τ1 +τ2) time since focus control is performed uniformly.

By the way, in the conventional device, the focus state stops at an undesired x3 state, and in the device of the present invention, the control unit 15 reverses the focus state by a period of (τ, +τ2) as shown in FIG. TV
Since the focus state of the TV left camera reaches the X state at time t2, the focus state of the TV left camera changes in the direction of returning to the state until time t3. The time required for this return is T, and as mentioned above, (τ, +τ2)
Since the time is equal to X, the focus state of the TV camera will eventually settle to the state desired by the operator. Note that the fact that a desired focus state can be achieved by reversing the focus state for T time in this way is based on the premise that the focus state changes uniformly (linearly) depending on the control signal. . Therefore, the control unit 1
5 must monitor that the focus state is changing uniformly at least for a period (τ1 +τ2) before the control signal stops. Normally, the focus state changes linearly as long as the control signal is continuously input, so instead of monitoring the focus state, the control unit 15 may monitor whether the control signal is continuously input. .

FIG. 3 is a flowchart illustrating the operations performed by the control section 15. First, at #1, the instant when the control signal turns on is detected. This is determined by differentiating the control signal within the CPU and determining whether a positive differential output is detected. and,
When the on-edge of the control signal is detected, the process proceeds to #2 and the CP
Turn on the timer in U-uchi. This causes the built-in timer to start counting time. − degrees, when the control signal is turned on,
The program advances in the order of #1 to #3 to EndoStar to #l, during which time the timer continues counting time.

Eventually, when the control signal stops, an off-edge of the control signal is detected at #3. This detection is performed depending on whether a negative differential output is detected within the CPU. When an off-edge of the control signal is detected, the timer is stopped (#
4), the counted time Tk of the timer immediately before stopping is (τ, +τ2
) is determined (#5). This determination is made to see whether the control signal has been continuously on for a period of (τ, +τ2) time past the time when the control signal was stopped. This is necessary to determine whether the TV left camera focus state is changing at least in (τ+τ2) time- as described above. #
If the judgment in step 5 is negative, the process ends without performing any processing, but if it is affirmative, a status return signal is issued and the process ends after step #6). This state return signal returns the focus state of the TV left camera to the desired state.

In the embodiment, control of the focus state has been explained as an example of TV left camera control, but it goes without saying that the control of the TV 4° camera direction, iris, zoom, etc. can also be realized by the same configuration and processing.

In addition, in the embodiment, among the delay time T, the signal processing time by each circuit is unique to the device and is known, but the delay time due to the transmission path between devices varies depending on the installation situation of the device. It is necessary to set the sum of both when installing.

Furthermore, in this embodiment, the upstream transmission line 13 and the downstream transmission line 14 are optical fibers, but these are not essentially necessary for the present invention, and if the influence of delay cannot be ignored, the transmission line may be used. The present invention is effective regardless of the type.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, according to the present invention, when the operation unit of the TV left camera and the TV monitor are separated, the occurrence of deviation in the setting state of the TV left camera due to signal delay in the circuit and transmission path can be corrected. The practical effects are great.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a video monitoring device according to an embodiment of the present invention, Fig. 2 is a waveform diagram of each part, Fig. 3 is a diagram explaining the operation of the control unit, and Fig. 4 is a diagram of a conventional video monitoring device. It is a block diagram. 1--Monitoring device, 2-Imaging device, 3-Operation section, 4 Multiplexing section, 5-1st E10 section, 6-10th/E section, 7...-Multiple decomposition section, 8-TV camera drive section , 9-TV left camera 10--2nd E10 part, 11-20th/E part, 12-
- TV monitor, 13.--up transmission line, 14.--down transmission line, 15.--control unit. Agent: Patent attorney Shiro Nakadaka (Chichicho Chokujuku) Figure 2 T (=τ1+τ2) Figure 3

Claims (1)

[Claims] (1) An imaging device having a television camera (hereinafter referred to as TV camera), a transmitting unit that is connected to the imaging device via a transmission line and transmits a control signal for the TV camera, and an image of the TV camera. A video monitoring device comprising a monitoring station having a TV monitor for receiving a signal, comprising: a first detection means for detecting that control by the control signal has stopped; and a first detection means for detecting that control by the control signal is stopped; a second detection means for detecting whether the control has changed uniformly from the past until the control stop point by a delay time that is the sum of the processing time and the time twice the signal delay time due to the transmission path; , a control section is provided on the imaging device side, and includes a state restoration means for returning the state of the TV camera to the past state by the delay time when the control has changed uniformly during the period. A video surveillance device featuring: