JP3445849B2 - Line monitoring equipment for video signals - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a remote monitoring system for grasping the situation of a site from a remote place, and automatically monitors a line state of a video signal. It relates to a line monitoring device. 2. Description of the Related Art A remote monitoring system for grasping the situation of a site from a remote place monitors, for example, a dam construction state or the inside of a hazardous material storage, or separates the progress of a work process in a company. It is used in various industrial fields, such as performing production management while grasping while staying in a place. In the video signal line monitoring device applied to the remote monitoring system, when investigating the line condition of the video signal, an operator or the like sequentially selects frequency channels in the device and selects the selected frequency. The level of the high-frequency signal corresponding to the channel, that is, the level of the video signal converted to the high-frequency signal, has been measured using a measuring instrument such as a spectrum analyzer. That is, the quality of the line state of the video signal is determined based on the measured level of the high-frequency signal. [0004] In addition, by converting a high-frequency signal corresponding to the selected frequency channel into a video signal and sequentially displaying the video signal on a monitor or the like, the operator can visually check the line condition of the video signal to obtain the above-mentioned signal. An investigation was underway. In the conventional video signal line monitoring apparatus described above, the level of a high-frequency signal sequentially selected by an operator or the like is measured in order to investigate the line state of the video signal. A measuring instrument such as a spectrum analyzer is required. In addition, it is necessary for an operator to check while changing the level of the high-frequency signal. For this reason, for example, when there is an abnormality such as a video signal line disconnection in a certain channel, there is a problem that it takes time and effort to search for and investigate this abnormality. In addition, there is a similar problem when an operator visually confirms an image projected on a monitor or the like. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a video signal line monitoring apparatus which automates the line monitoring of a video signal and facilitates maintenance and maintenance of the line. SUMMARY OF THE INVENTION The present invention relates to a video signal line monitoring apparatus for monitoring the situation of a site from a remote place, and an ITV camera for imaging the situation of the site and this ITV.
A modulator that converts a video signal captured by a V camera into a high-frequency signal and sets a different frequency channel for each ITV camera; and a distributor that synthesizes / distributes the high-frequency signal converted by the modulator. A plurality of on-site monitoring devices, a level detector for detecting a level of a high frequency signal sent from the plurality of on-site monitoring devices, and a controller for sequentially selecting the frequency channel for the level detector And a line monitoring unit consisting of a display for displaying a list of changes in levels of high-frequency signals corresponding to a plurality of frequency channels sequentially selected by the controller in a time-series manner, and a high-frequency signal transmitted from the plurality of site monitoring devices. On the other hand, a demodulator that performs processing to convert to a video signal and an arbitrary frequency channel are set for this demodulator. And a monitor TV for displaying an image of a relevant site based on a video signal corresponding to the arbitrary frequency channel set by the operating device. . The situation at each site is captured by the ITV camera of each of the plurality of site monitoring devices, and each video signal is converted to a high-frequency signal by a modulator in which a different frequency channel is set for each ITV camera. Is done. The converted high-frequency signals are combined by the distributors in the plurality of on-site monitoring devices and sent to a level detector in a line monitoring unit installed at a location remote from each site and a demodulator in a remote monitoring device. Be distributed. Next, a controller in the line monitoring unit sequentially selects different frequency channels set for each of the modulators. The level detector detects a level of a high-frequency signal corresponding to a frequency channel sequentially selected by the controller and sends the detected level to the controller. The controller sends the level of the high-frequency signal to a display, and displays a list of changes in the level of the high-frequency signal for each of the selected plurality of frequency channels on the display. Next, the operator grasps the quality of the line condition from the level of the high-frequency signal for each of the plurality of frequency channels displayed on the display, and if the line of the video signal on a certain frequency channel has any line abnormality. Investigate the applicable site monitoring equipment when is confirmed. As described above, a plurality of different frequency channels are sequentially selected by the controller in the line monitoring unit, and the level detector detects the level of the high-frequency signal corresponding to the selected channel, and the level detector detects the level of the plurality of different frequency channels. Since the level change of the corresponding high-frequency signal is displayed in a list on the display for each channel, it is possible to automate the line monitoring of the video signal. As a result, it is possible to constantly monitor the line. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a video signal line monitoring apparatus according to an embodiment of the present invention. In FIG. 1, reference numerals 1a to 1c denote site monitoring devices installed at each site. This site monitoring device 1a-1
c comprises an ITV camera 2, a modulator 3, and a distributor 4, respectively. The ITV camera 2 displays the situation of each site to be monitored and sends each video signal to the modulator 3. Different frequency channels are assigned to the modulators 3 of the site monitoring devices 1a to 1c, respectively. The modulator 3 converts the video signal into a high-frequency signal and sends it to the distributor 4. The distributor 4 in the on-site monitoring device 1a and the distributor 4 in the on-site monitoring device 1b are connected in a bus shape by a coaxial cable 5. Similarly, the distributor 4 in the site monitoring device 1b and the distributor 4 in the site monitoring device 1c
Are connected by a coaxial cable 5. The distributor 4 combines and distributes the high-frequency signal converted by the modulator 3. On-site monitoring equipment 1
The high-frequency signals synthesized by the distributors 4a to 1c are transmitted from the distributor 4 in the on-site monitoring device 1c to the monitoring unit 6 installed at a location remote from each site via the coaxial cable 5. The monitoring unit 6 includes a distributor 7, a line monitoring unit 8, and a remote monitoring device 9. The distributor 7 distributes the synthesized high-frequency signal transmitted from the distributor 4 of the site monitoring device 1c to the line monitoring unit 8 and the remote monitoring device 9, respectively. The line monitoring unit 8 includes a level detector 10, a controller 11, and a display 12, and the distributed high-frequency signal is input to the level detector 10. The level detector 10 is connected to a controller 11. The controller 11 is provided with the on-site monitoring device 1
a for sequentially selecting different frequency channels assigned to each of the modulators 3a to 1c.
Send to 0. With respect to the distributed high-frequency signal, the level detector 10 converts the high-frequency signal corresponding to the selected frequency channel into an intermediate frequency, detects the level, and outputs the detected level to the controller 11. As a result, the controller 11 lists the levels of the high-frequency signals corresponding to the selected frequency channels on the display 12 in chronological order. The high frequency signal distributed and output by the distributor 7 and transmitted to the remote monitoring device 9 is input to the demodulator 13 in the remote monitoring device 9. An operation device 14 is connected to the demodulator 13. The operating device 14 controls the demodulator 13 by selecting a different frequency channel set for the modulator 3 of each of the site monitoring devices 1a to 1c. The demodulator 13 converts a high-frequency signal corresponding to the frequency channel selected by the operation device 14 into a video signal and outputs the video signal to the monitor TV 15. The monitor TV 15 displays an image of a corresponding site based on the converted video signal. The remote monitoring device 9 includes a demodulator 13, an operating device 14, and a monitor TV 15. Next, the operation of the above embodiment will be described.
Three ITs in the site monitoring devices 1a to 1c shown in FIG.
The image of each site situation projected by the V camera 2
The signals are respectively sent to three modulators 3 to which different frequency channels are assigned, and are converted into high-frequency signals.
The high-frequency signals converted by the three modulators 3 are combined in the distributors 4 of the site monitoring devices 1a to 1c. Next, the synthesized high-frequency signal is
The signal is output from the distributor 4 in the on-site monitoring device 1c to the distributor 7 in the monitoring unit 6 via the coaxial cable 5. Distributor 7
Distributes and outputs the synthesized high-frequency signal to the level detector 10 in the line monitor 8 and the demodulator 13 in the remote monitor 9. On the other hand, the controller 11 issues a command for sequentially selecting different frequency channels set in the modulators 3 of the on-site monitoring devices 1a to 1c.
To send to. The level detector 10 converts a high-frequency signal corresponding to the frequency channel selected by the controller 11 into an intermediate frequency, and outputs the signal level to the controller 11. Next, as shown in FIG. 2, for example, the controller 11
(The site monitoring devices 1a to 1c are CH1 to CH3, respectively.
It corresponds to. ), The level of the high-frequency signal for one week, that is, the level of the video signal converted into the high-frequency signal is graphed and displayed on the display 12. In FIG.
If the level is equal to or higher than the "OK" level, the line state in the corresponding channel is considered to be good. If the level is equal to or lower than the "NG" level, it is determined that there is some abnormality in the line state. Here, the display 12 of the line monitoring unit 8 includes:
The fluctuation of the level of the video signal converted into the high frequency signal for each frequency channel is displayed. The operator uses the operation device 14 based on the display result of the display device 12 to select, for example, a frequency channel that is considered to be abnormal in the line.
Perform for 3 The demodulator 13 converts the high-frequency signal corresponding to the selected frequency channel into a video signal with respect to the high-frequency signal transmitted from the distributor 7 and converts the high-frequency signal into a video signal.
5 is output. The monitor TV 15 displays an image of a corresponding site based on the image signal. The operator monitors and grasps the situation at the site based on the image. As described above, the level detector 10 detects the level of the high-frequency signal corresponding to each of the plurality of different frequency channels selected by the controller 11, and converts the level of the high-frequency signal detected by the controller 11 into a time series. Is displayed on the display unit 12 so that CH1 is displayed.
~ Site monitoring device 1a corresponding to each channel of CH3 ~
It is possible to judge the quality of the line state in 1c according to the passage of time. That is, it is easy to determine whether or not the line state in the corresponding channel has really deteriorated by looking at the level change for one week, for example, instead of the level of the temporary high-frequency signal. In addition, since the level of the high-frequency signal can be detected without using a measuring instrument such as a spectrum analyzer, the line monitoring of the video signal can be unmanned, that is, automated. As a result, it is possible to realize line monitoring that is much more efficient in terms of time than visual confirmation by an operator. In addition, because it is possible to constantly monitor,
Even when a trouble such as a line disconnection occurs, the maintenance of the relevant line can be performed promptly. Therefore, maintenance of the line becomes easy. In the above embodiment, three site monitoring devices have been described. However, it is naturally possible to provide four or more site monitoring devices to monitor the line of the video signal. As described above, according to the present invention,
By sequentially selecting a plurality of different frequency channels by the controller in the line monitoring unit, by the level detector, by detecting the level of the selected high-frequency signal, and to output and record the level of this high-frequency signal in time series, Since the line monitoring of the video signal can be automated and the line state can be constantly monitored, it is possible to easily maintain and maintain a good line state.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a video signal line monitoring apparatus according to an embodiment of the present invention. FIG. 2 is an exemplary view showing a display example of a display device in the embodiment. [Description of Signs] 1a to 1c On-site monitoring device 2 ITV camera 3 Modulator 4, 7 Distributor 5 Coaxial cable 6 Monitoring unit 8 Line monitoring unit 9 Remote monitoring device 10 Level detector 11 Controller 12 Display 13 Demodulator 14 Operation Unit 15 Monitor TV

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H04N 17/00 H04N 7/18 H04J 1/00

Claims (1)

(57) [Claims 1] In a line monitoring apparatus for a video signal for monitoring the situation of a site from a remote place, an ITV camera for imaging the situation of the site, and an image captured by the ITV camera Convert the signal to a high frequency signal,
A plurality of on-site monitoring devices including a modulator in which a different frequency channel is set for each ITV camera, and a distributor for synthesizing / distributing a high-frequency signal converted by the modulator; A level detector for detecting the level of this signal with respect to the high-frequency signal sent from the controller, a controller for sequentially selecting the frequency channel for the level detector, and a plurality of frequency channels sequentially selected by the controller. A line monitoring unit comprising a display for displaying a list of changes in the level of the high-frequency signal in a time-series manner; and a demodulator for converting a high-frequency signal sent from the plurality of on-site monitoring devices into a video signal. An operation device for setting an arbitrary frequency channel to the demodulator, and the above-described arbitrary Based on the video signal corresponding to the wave number channels, the corresponding field line monitoring apparatus of the video signal, characterized by comprising a remote monitoring device comprising a monitor TV to view the picture of.