JPH02166986A - Video surveillance - Google Patents

Abstract

PURPOSE: To provide an inexpensive and flexible system by multiplexedly transmitting modulated signals from plural video cameras, applying signals to plural video screens and tuners in parallel by a signal splitter and controlling the tuners by a computer. CONSTITUTION: Respective video modulators 2 modulate signals outputted from cameras 1 and plural combiners 3 connected in series apply the signals from all the modulators 2 to the signal splitter 4 through a video signal transmission line 5. The splitter 4 supplies the received signals to plural video display devices 6, each of which transmits the supplied signal to a channel selected by a tuner 7 and a display screen 8 displays a picture included within the visiual field of the camera 1. The computer controls the tuners 7 and executes sequence control so as to display pictures observed by a series of cameras 1 on the screen 8. Consequently the flexible system reducing wiring cost can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Summary of the Invention A video surveillance system is disclosed,
In this system, modulated signals from multiple video cameras are multiplexed onto a signal transmission path that can carry, for example, up to 36 video channels. One or more communication paths are provided to the signal splitter, which provides a path to one or more video screens and tuners. The tuner is operated under computer control and sequences the display of information from different video cameras. It is advantageous to provide means for recording the video display on the video screen when content of interest is being displayed. The computer displays signals from one or more video cameras in an area proximate to the alarm signal generating means on one or more screens in response to the alarm signal input.

INDUSTRIAL APPLICATION This invention relates to video surveillance systems, and more particularly to video surveillance systems employing a plurality of cameras and one or more video screens displaying the fields of view of the cameras.

Problems with the Prior Art Typically, video surveillance systems install video cameras at appropriate locations to monitor the entire facility to be monitored. Each camera is connected in series to a control console at which the video signal is displayed as an image. Such systems have significant wiring costs and limited flexibility.

SUMMARY OF THE INVENTION In the present invention, modulated signals from a plurality of video cameras are multiplexed onto a cable capable of carrying signals of, for example, a single channel or up to 36 video channels. One or more such communication paths are provided in the signal splitter to provide parallel paths to each of the plurality of video screens and the tuner. The tuner is operated under computer control to sequence information from different video cameras and display it on a screen. It is advantageous to also provide means for recording a video display on the VCR, if the display contains material of interest.

In a preferred embodiment of the invention, the computer responds to the alarm input by displaying signals from video cameras in the vicinity of the location of the alarm signal on one or more screens.

Embodiment As shown in FIGS. 18 and 1B, the system of the present invention includes a plurality of video cameras l, each camera connected to a video modulator 2. Each video modulator 2 modulates the signal from the connected camera at a unique channel frequency and provides a video output signal to a combiner 3, which combines the signals from all modulators 2 into a video signal transmission path 5. give. A series of several such combiners 3 (two shown in the figure) are connected in series and supply signals to a signal splitter 4 via a transmission path 5.

For convenience of explanation, it is assumed that the video signal transmission path 5 has a capacity of 36 channels and can therefore accommodate 36 video cameras 1 (16 cameras are shown in the drawing). If necessary, an additional video signal transmission path 5 can be connected between an additional video camera (not shown) and the signal splitter 4.

This signal splitter 4 provides signals received via a single or multiple video signal transmission paths 5 onto a plurality of video display devices 6, each of which has a tuner 7 and a display screen 8. It consists of Depending on the channel selected by tuner 7, the signal from the video camera is transmitted to the channel selected by tuner 7 so that display screen 8 displays whatever is within the field of view of video camera l.

According to the invention, the combiner 10 controls the tuner 7 and provides a signal to the display on the screen 8.

According to the invention, the computer 10 controls the tuner 7 and thereby sequences the images being viewed by the series of cameras l to be displayed on the stern 8. For example, a computer may control a video display tuner such that its screen continues to display a series of images that may be encountered, such as someone passing through a floor or building.

As shown in FIG. 1, for example, one or more video display devices may be connected in parallel to the path 5 to provide respective displays from different series of cameras or to be particularly closely monitored. It is also possible to perform dense monitoring of an area.

Alternatively, each video display means 6 may be connected to only a single transmission path 5.

Further according to the invention, the system includes one or more alarm inputs 12, such as a fire alarm or intruder alarm, connected by conductors 13 to the computer 10; one or more switch matrices 14; and at least one or more video display means 6 in parallel. may include one or more video display devices 16 connected to. switch matrix 1
4 may be a rotary switch, for example. Each display device 16 has a tuner 17. It includes a display screen 18 and a video recorder (VCR) 19.

In response to a signal from one alarm input, the computer 10 identifies the area where the alarm was triggered and switches the wiper arm 15t of the switch matrix 14 to the video signal transmission path 5 coming from this area. It also identifies one or more cameras proximate to the alarm input, ascertains the channel frequencies of those cameras, and uses a tuner to tune one or more video display devices to the channel frequencies associated with those cameras.

It is also desirable to enable the VCR 19 to record the display contents of a video display device connected thereto during the alarm condition.

The components of the system of FIG. 1 are generally commercially available. For example, video camera 1 is RCA's TC-201.
1. Modulator 2 is Blonder-Tongue's MVM modulator, combiner 3 is 2FSC-12
-1-75 minicircuit, the video display device 6 may be a conventional TV set, preferably with an electronic remote control (tuner) attached. For example, such a tuner may be modified as described with respect to FIGS. 2A and 2B.

Computer 10 may be a personal computer, such as an IBM-PC or a clone thereof. In order to control the tuner and switching matrices mentioned above, computer 10 maintains a number of lists in its memory. The first list collects the data of each video camera l along with its channel frequency and its signal transmission path 5 data. The second list collects data for each alarm input along with data from one or more cameras that observe areas of interest when that alarm input is activated. The third list identifies the family of video display devices and video cameras from which signals are to be displayed on the associated display device. Preferably, this list also specifies the duration of the display of each video camera's field of view. Each of these lists is entered from a keyboard associated with the memory of the computer IO and updated as conditions change.

In operating the system of the present invention, these three lists are entered into the computer's memory, and the system thus begins to control the tuner 7 of each video display device 6. To do this, the computer reads the identification data of tlgl's camera from the third list and causes information from that camera to be displayed on the first video display device. The computer then uses the first camera's identification data to read parameters from the first list that identify the channel frequencies over which signals from that camera are transmitted, and the computer uses these parameters to identify the first video display tuner 7
to tune to that channel frequency. The computer repeats the above steps so as to provide the other video display devices 6 with the signal from the first camera identified in the third list to be displayed on each of these display devices. . The computer then repeats these steps to identify additional cameras on the display list for each video display device.

The computer cycles through these display lists in a similar manner, and this process continues indefinitely. While performing these tasks, the computer also monitors alarm inputs. When an alarm input is received, the computer uses the identification data of the alarm input to read from the second list the identification data of one or more cameras proximate to the alarm emitting the alarm, and the computer uses the identification data of the alarm input to Determined to be useful in emergency situations. The computer uses the identification data of each camera to read the identification data of the channel frequency and its signal transmission path 5 from the first list. This signal transmission path identification data is used by the computer to set one or more switching matrices 14 to connect the signal transmission path to the tuner 17 of the video display device 16, and to set the parameters identifying the channel frequency as appropriate. is used to tune the tuner 17 to the appropriate channel frequency to display the signal from the camera of interest. Preferably, the computer also activates one or more VCRs 19 to record high resolution signals from the associated camera or cameras during the emergency situation.

Tuner 7 and tuner 17 are shown in @'2A figure and 2B.
It is computer controlled by a circuit 20 shown in the figure, which resembles a conventional TV remote control circuit. The conventional TV remote control unit includes a keyboard, keyboard encoding circuit, and NECuPD19
13c-like remote control chip. The keyboard encoder generates signals representing the keys pressed on the keyboard and provides these signals to the remote control chip. The remote control chip uses these signals to generate a unique pulse train, which feeds into an infrared light emitting diode, which in turn generates an infrared pulse train to send to the TV.
Transmits to the upper set infrared detection device. The light pulses received by the infrared detection device are converted to a train of electrical pulses that are received by the TV's tuner circuitry and used to set the tuner to the desired channel frequency.

As shown in FIGS. 2A and 2B, circuit 20
includes a plurality of keyboard simulators 22, a plurality of remote control circuits 24, a strobe circuit 26, and a component carrier 28, the component carrier 28 having passive components commonly used to generate output signals from the circuits 24. As a keyboard simulator,
For example, the RCA CD22100 circuit is used, and the remote control circuit is the NECuPD1913c integrated circuit.

Circuit 20 is adapted to control four separate tuners 7 or 17 through the REM output from each circuit 24. Some tuners outside? It can be controlled by changing the number of &22.24.28.

The channel frequency information stored in the first list in the component carrier has a different bit pattern for each channel to be selected. When we read a bit pattern like this from the first list,
The computer supplies this pattern to signal lines KAO-KA3. The signals on these four signal lines are used to select one of 16 different video channels. By increasing the number of signal lines, more channels can be selected. Strobe circuit 26 determines which keyboard simulator 22 is decoding this pattern and provides an output on one of lines Xl-X4 and Yl-Y4 to identify the unique bit pattern.

This signal represents a key press on the remote control channel tuner. This signal is provided to the remote control tuner circuit 24 where the REM 5HU
It is used to generate a pulse train to the TSURYOKU, which in the past has been used in a conventional manner to generate pulses to a light emitting diode.

However, in the present invention, this pulse train is provided directly to the video display device by a hardwired connection, where it is connected to the output signal line (not shown) from the infrared detection device.
connected to. This infrared detection device traditionally receives infrared pulses from a remote control tuner. 2nd B
Resistor R9 in the figure is used to adjust the amplitude of the signal so that the output signal of the photodetector can be compared in magnitude with the signal present when the infrared pulse is occurring.

It will be apparent to those skilled in the art that many modifications may be made in carrying out the invention without departing from its spirit. The transmission path may be a coaxial cable, a short wave signal or other communication channel suitable for transmitting video signals. The camera locations may be in a relatively small area, distributed within one or more buildings, or even in widely dispersed areas around the world. The camera may be fixed or movable. Also, one or more cameras can be provided on a movable robot. If desired, each camera can be provided with a digital input.

There are countless fields of application for the present invention. In addition to regular video surveillance, the system of the invention can also be used, for example, to control access to closely monitored areas.

[Brief explanation of the drawing]

FIG. 1A and FIG. 1B are schematic diagrams each showing a part of the arrangement of a preferred embodiment of the present invention, and the portion of FIG. 1A and the portion of FIG. 1B are indicated by dashed lines in the respective figures. 2A and 2B are block diagrams of a portion of the circuit used in carrying out the present invention, respectively, and FIG. 2A and FIG.
The part shown in the figure and the part shown in FIG. 2B are connected to each other via corresponding conductive wires at the portion indicated by a chain line in each figure to form a whole. Explanation of symbols 1: Camera, 2: Modulator, 3: Combiner, 4:
Signal splitter, 5: Video signal transmission path, 6: Video display device, 7: Tuner, 8: Display screen, 1
0: Computer, 12: Alarm input, 13: Conductor, 14
: Switch matrix, 15: Wiper arm, 16: Video display device, 17: Tuner, 18: Display screen, 19: Video recorder (VCR), 20: Circuit, 22: Keyboard simulator, 24: Remote control circuit, 26: Strobe Circuit, 28: Component carrier,

Claims (1)

[Scope of Claims] [1] A plurality of video cameras, means for modulating signals from each of the cameras, means for multiplexing the modulated signals onto a signal transmission path for transmitting the modulated signals to a plurality of video channels, and the signal transmission path. a signal splitter that provides the above signal in parallel to a plurality of video display devices, each having a tuner and a display screen; a computer having means for displaying a sequence of images from a computer on its display screen. [2] In the video surveillance system according to claim 1, a plurality of alarm generating means, means for connecting the alarm generating means to the computer, and in response to an alarm signal from the alarm generating means, A video device comprising means in the computer for controlling at least one of the tuners, thereby displaying on a display screen an image from a video camera close to the alarm generating means that has issued the alarm. Surveillance system. [3] The video surveillance system according to claim 1, further comprising means for recording the display on the display screen. [4] In a predetermined surveillance area,
a plurality of video cameras positioned at predetermined observation points, each of said video cameras having a video output, means for modulating said video output signal in a predetermined frequency band; a plurality of video cameras in different frequency bands; a signal transmission path for carrying a modulated signal; means for connecting each of said modulation means to said signal transmission path; and an observation control station, said control station comprising selectable tuner means, demodulation means, and video display means. and said tuner means is connected to said signal transmission path, and said demodulation means is connected between said tuner means and said display means, whereby said predetermined frequency is determined by adjustment of said tuner means. one of the bands is selected and demodulated and displayed on said video display means, thereby displaying the selected observation point on said display means, and sequence means are provided, said sequence means capable of said selection. means for adjusting a tuner to select one of said predetermined frequency bands, said sequence correlating each of said predetermined frequency bands with one of said observation points; the video signal generated by the camera at every observation point can be displayed on said video display means, said sequence means giving a duration to each of said frequency bands, and said sequence means giving a duration to each of said frequency bands; a video surveillance system characterized in that it comprises means for allocating the order of said frequency bands so that the video signals from said video signals are displayed on said video display means in a predetermined order and for a predetermined period of time. . [5] The video surveillance system according to claim 4, comprising a plurality of signal transmission paths, each of the signal transmission paths being capable of transmitting N modulated signals, and the signal transmission path each can be connected to up to N video cameras positioned at predetermined observation points, each camera being provided with modulation means for modulating said video output into N different frequency bands. and has a plurality of selectable tuner means, the number of the tuner means corresponds to the number of signal paths of the signal transmission paths, and each tuner means is connected to one of the signal transmission paths. and capable of selectively tuning each of the modulated signals generated by the modulating means and connected to a signal transmission path to which the tuner is connected, each of said tuner means being connected to said video display means. selectable switch means for connecting, said sequence means controlling said switch means, means for associating each of said observation points with a frequency band and a signal transmission path;
A video surveillance system characterized in that the number of observation points that can be displayed on the display means can be increased stepwise up to N. [6] The video surveillance system according to claim 4, further comprising a plurality of selectable tuner means, a demodulation means, and a video display means connected to the signal transmission path, whereby a plurality of A video surveillance system characterized by being able to display observation points simultaneously. [7] The video surveillance system according to claim 4, including a plurality of alarm signal generating means arranged at predetermined monitoring points, at least one monitoring device corresponding to one of the observation points. means for connecting said alarm signal generating means to said sequence means, said sequence means being provided with means responsive to said alarm signal generating means, and generating said alarm signal at a monitoring point corresponding to one of said observation points; means for associating the means with a frequency band corresponding to said observation point, such that when one of said alarm signal generating means generates an alarm signal at a monitoring point corresponding to one of said observation points; A video surveillance system characterized in that a video signal from a video camera placed at the observation point is displayed on the display means. [8] The video surveillance system according to claim 4, wherein the sequence means includes information associating each of the observation points with one frequency band, and information associating each frequency band with a priority and duration. input means for accepting said observation points, thereby enabling the user to direct the control station to display the video signals associated with said observation points in a desired order and for a desired duration. video surveillance system. [9] The video surveillance system according to claim 4, further comprising recording means for recording the signal displayed on the display means, and means for controlling the recording means to the sequence means. A video surveillance system characterized by the provision of. [10] The video surveillance system according to claim 5, wherein each of the signal transmission paths is connected to the plurality of selectable tuner means, demodulation means, and video display means, whereby the signal A video surveillance system characterized in that the plurality of observation points connected to each of the transmission paths can be displayed simultaneously. [11] In the video surveillance system according to claim 5, a plurality of alarm signal generating means are arranged at a plurality of predetermined monitoring points, and at least one monitoring point is located at a plurality of predetermined monitoring points. said plurality of alarm signal generating means corresponding to one of said alarm signal generating means, means for connecting said alarm signal generating means to said sequence means, means for responding to said alarm signal generating means to said sequence means, and said observation point. means for associating said alarm signal generating means at said monitoring point corresponding to one of said observation points with said frequency band and one of said signal transmission paths corresponding to said observation point, thereby A video surveillance system characterized in that when an alarm signal is generated by the alarm signal generating means at the one monitoring point, a video signal from a video camera placed at the observation point is displayed on the display means. [12] The video surveillance system according to claim 5, wherein the sequence means includes information associating each of the observation points with the frequency band and the signal transmission path, and assigns priority and duration to each frequency band. characterized in that input means are provided for receiving information relating to the observation points, whereby the control station can be directed, according to the user's selection, to display the video signals associated with the observation points in a desired order and for a desired duration. video surveillance system. [13] The video surveillance system according to claim 5, further comprising means for recording the signal displayed on the display means, and means for controlling the recording means in the sequence means. A video surveillance system featuring: [14] A video surveillance method characterized by the following: each video camera is installed at N predetermined observation points; each video camera receives N output signals from each camera; a first signal transmission path capable of transmitting the N modulated signals such that the first signal transmission path extends to a circuit serving each of the N observation points; connecting each of said N modulation means to said first signal transmission path; and selecting with respect to a monitor station a location to be monitored along said first signal transmission path. providing the monitor station with a selectable first tuner capable of tuning each of the N frequency bands;
connecting said selectable first tuner to said first signal transmission path at said monitoring location; providing said monitoring station with video display means and connecting said display means to said first tuner; associating N frequency bands with one of the observation points; adjusting the first tuner to select the associated frequency band for the observation point to be displayed; [15] The method of claim 14, comprising: associating a duration with each of the N frequency bands; ordering the frequency bands into a sequence; and adjusting the first tuner. selecting each of said frequency bands in said sequence and displaying said associated observation point on said display means for a duration associated with said frequency band associated with said observation point; A video surveillance method further characterized by: [16] The method according to claim 14, further comprising: further disposing one video camera at M preselected observation points; providing a modulation means for modulating the output signal from the camera into one of M further different frequency bands; a circuit for transmitting the M modulated signals to each of the M further observation points and the monitor point; The second message is extended to
connecting said M modulation means to said second signal transmission path; and providing said monitor station with a second selectable tuner to tune each of said M frequency bands. tuning and connecting said selectable tuner to said second signal transmission path at said monitoring point; connecting switch means between said first and second tuners and said display means; associating each of the further M observation points with the second signal transmission path; and associating each of the N observation points with the second signal transmission path; associating it with a first signal transmission path; and adjusting said switch means and said tuner to select a frequency band and signal transmission path associated with an observation point to be displayed. [17] The method of claim 16, further comprising: associating a duration with each of the M frequency bands; ordering the N and M observation points into a sequence; and adjusting a switch means to select each of said frequency band and said signal transmission path in said sequence and said association for a duration associated with said frequency band and said signal path associated with said observation point. displaying each of the observed observation points on the display means;