JP2534787Y2 - Monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a monitoring apparatus having a transmitter for transmitting monitoring information and a receiver for receiving monitoring information from the transmitter, and particularly to starting the monitoring apparatus. About the procedure.

[Outline of the invention]

According to the present invention, a monitoring device including a transmitter for transmitting monitoring information and a receiver for receiving monitoring information from the transmitter includes a control unit that controls power of the transmitter and the receiver. By turning on the power of the transmitter at startup and then turning on the power of the receiver, and turning off the power of the receiver and turning off the transmitter at the end of transmission,
This is intended to prevent a phenomenon in which the transmission frequency of the receiver cannot be pulled in at the time of starting the transmission and to prevent generation of annoying sounds of the receiver at the end of the transmission.

[Conventional technology]

In recent years, it has been required to provide remote monitoring devices in various places as a security measure for houses and the like and as a theft prevention measure. As a general configuration of this type of monitoring apparatus, a monitoring location is photographed by a video camera, and a video signal output from the video camera is monitored by a monitor television. Also, when the house is away, etc., the video signal is recorded on a video tape recorder (hereinafter referred to as VTR) instead of monitoring on the monitor television, and then monitored on the monitor television. Had been.

[Problems to be solved by the invention]

By the way, in such a monitoring apparatus, no problem occurs when the transmission frequency and the reception frequency are exactly the same, but in general, they do not match. Therefore, the receiver has an automatic frequency tuning mechanism, and the transmission frequency ( Go for a career) and try to pull in. Therefore, when the search is performed and no such carrier is found, the operation is stopped because there is no transmission carrier.

Therefore, if the receiver is turned on earlier than the transmitter at the start of transmission, the receiver may not be able to pull in the frequency. Also, if the transmitter is turned off earlier than the receiver at the end of transmission,
The receiver determines that the transmission level has dropped and raises the AGC to full gain to work on receiving.
Will be generated.

The present invention has been made in view of such a point, and provides a monitoring device capable of always performing stable reception.

[Means for solving the problem]

For example, as shown in the drawing, the monitoring device of the present invention includes detecting means (21a) (21b) (21c) (21d) for detecting an intruder, and monitoring cameras (4a) (4b) (4c) (4d) for photographing a monitoring place When,
A transmitter for modulating the video of the surveillance camera at a predetermined transmission frequency and transmitting the same, and detecting means (21a) (21b) (21c)
A first method for controlling the power of the transmitter according to the output of (21d) and transmitting power control information via the transmitter.
Control means (22a) (22b) (22c) (22d), an automatic frequency tuning circuit for tuning to the transmission frequency of this transmitter, and an AGC circuit for controlling the gain according to the transmission level of this transmitter. A receiver for receiving video and power control information from the transmitter; and second control means (23) for controlling the power of the receiver in accordance with the received power control information. (21a)
(21b) The first control means (22a) (22b) (22c) at the start of transmission when detection outputs from (21c) and (21d) are obtained.
(22d) transmits the power control information after turning on the power of the transmitter, and the second control means (23) turns on the power of the receiver when the power control information is received. The detection means (21a) (21b)
At the end of transmission when the detection output from (21c) and (21d) cannot be obtained, the first control means (22a) (22b) (22c) (2
2d) transmits the power control information to the second control means (23), turns off the power of the receiver by the second control means (23), and then turns off the power of the transmitter. It is like that.

[Action]

Transmitters (4a-4d, 5a-5d, 6a-6c) and receivers (9d, 11,
Control means (21a to 21d, 22a to
According to 22d, 23), at the start of transmission, the power of the transmitter is turned on and then the power of the receiver is turned on. At the end of transmission, the power of the receiver is turned off and the power of the transmitter is turned off. This allows
At the start of transmission, the phenomenon that the receiver cannot pull in the transmission frequency is prevented, and at the end of transmission, no harsh sound is generated from the receiver.

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In the figure, (1) is a coaxial cable as a transmission path. This coaxial cable (1) is connected to a choke coil (2)
To the DC power supply (3) via. And in this case,
The four monitoring locations are photographed by different first, second, third and fourth video cameras (4a), (4b), (4c) and (4d), respectively, to obtain video signals. The video signals captured by the first to fourth video cameras (4a) to (4d) are respectively
2, the third and fourth modulators (5a), (5b), (5c)
And (5d) to mix the respective video signals with the audio signals and convert them to RF-modulated RF video signals. At this time, the first, second, and third modulators (5a),
(5b), (5c) frequency band f ₁ which is suitable for radio transmission, f _2, f ₃
Converted to, the fourth modulator (5d) is converted into a frequency band f ₄ of no free channels of television broadcasting.

RF video signals converted by the first, second, and third modulators (5a), (5b), and (5c) are converted into first, second, and third transmitters (6a), (6b), and (6c). The first to third transmitters (6a) to (6c) modulate the RF video signal into a predetermined transmission signal, and are connected to the first to third transmitters (6a) to (6c). An RF video signal modulated to a transmission signal is transmitted from the first, second, and third transmission antennas (7a), (7b), and (7c). Further, the RF video signal converted by the fourth modulator (5d) is supplied to the coaxial cable (1).

The transmission signals transmitted from the first to third transmission antennas (7a) to (7c) are converted into first, second and third reception antennas (8a),
(8b) and (8c) to receive the respective antennas (8a) to
The received signal of (8c) is converted into first, second and third receivers (9a),
(9b) and (9c), and the respective receivers (9a)-(9
In c), a signal of a predetermined frequency corresponding to the transmission signal is selected and demodulated into an RF video signal. The RF video signals demodulated by the first to third receivers (9a) to (9c) are supplied to first, second, and third converters (10a), (10b), and (10c). The first to third converters (10a) to (10c)
Converts the supplied RF video signal into RF video signals f ₅ , f ₆ , f ₇ of a frequency of an open channel without television broadcasting suitable for supplying to the coaxial cable (1), for example.
At this time, the frequency f ₅ ~f ₇ of the first to third converter (10a) ~ (10c) is converted, the empty channel of a frequency close together with the output signal frequency f ₄ of the fourth modulator described above (5d) Convert. Then, RF video signals are supplied from the first to third converters (10a) to (10c) to the coaxial cable (1).

The coaxial cable (1) is connected to an antenna line input terminal of a television receiver (11) for receiving a normal television broadcast to thereby provide the television receiver (11).
In the conversion by the above-described converter (10a) ~ RF video signal f ₅ ~f ₇ was converted with (10c) or the fourth modulator (5d)
By matching the desired broadcast channel corresponding to the frequency f ₄ of the RF video signal, first to fourth video camera (4a)
~ (4d) can show the video signal taken,
It can monitor four monitoring locations.

In the monitoring device of this example, a microcomputer (CPU) (12) is connected to a coaxial cable (1) via a fifth modulator (5e). Supply a control signal to (20) and the like. Also, the coaxial cable (1) is connected to the channel scan circuit (13). The channel scan circuit (13) includes a channel switching circuit (14) and a tuner (1).
5), intermediate frequency amplifier (16a) and video detector (16b)
And an audio circuit (16c) and a motion detection circuit (17). The RF video signal supplied to the coaxial cable (1) is supplied to the tuner (15).

The channel switching circuit (14) is a circuit for supplying a receiving channel selection signal to the tuner (15) and the microcomputer (12). Unless a motion detection signal described later is supplied from the motion detection circuit (17), the channel switching circuit (14) is provided at predetermined intervals. A reception channel selection signal is output so as to change the reception channel. When the reception channel selection signal to the tuner (15) is supplied, it demodulates the RF video signal of a frequency band corresponding to the selection signal the feed (either f ₄ ~f _7), the demodulated video signal To the intermediate frequency amplifier circuit (16a). The output signal of the intermediate frequency amplification circuit (16a) is supplied to a video detection circuit (16b), and the video detection circuit (16b)
Detects the video signal and separates the audio signal to be supplied to a motion detection circuit (17) in a channel scan circuit (13) and a monitor television (17) connected to the channel scan circuit (13). 18) and
Supply to VTR (19). The audio signal separated by the video detection circuit (16b) is supplied to the monitor television (18) via the audio circuit (16c).

The motion detection circuit (17) is a circuit for detecting the motion of the supplied video signal. For example, when a person enters a monitoring place where a video camera is shooting and there is a movement, the video signal captured by the video camera is detected. Is a circuit for detecting motion. When the motion detection circuit (17) detects the motion of the video signal, it supplies a motion detection signal to the channel switching circuit (14), the VTR (19) and the microcomputer (12).
When the motion detection signal is supplied to the channel switching circuit (14), the channel switching circuit (14) continuously demodulates the channel of the video signal in which the motion is detected to the tuner (15) for a predetermined time. Is output. When a motion detection signal is supplied to the VTR (19),
The VTR (19) records a video signal for a predetermined time. Further, when the motion detection signal is supplied to the microcomputer (12), a reception channel is detected by the reception channel selection signal output from the channel switching circuit (14) at this time, and the reception channel such as the reception channel having the motion is detected. information and monitoring information signal, supplied from the microcomputer through the fifth modulator (5e) (12) to the coaxial cable (1) as a signal of a predetermined frequency band f _8.

Further, a fourth transmitter (6d) is connected to the coaxial cable (1), and the fourth transmitter (6d) has a frequency band f corresponding to the signal supplied from the microcomputer (12). Only the _eight signals are transmitted from the fourth transmitting antenna (7d). The transmission signal is received by a fourth reception antenna (8d), and the transmission signal is demodulated by a fourth receiver (9d) connected to the fourth reception antenna (8d). Supply to (20). The alarm (20) emits, for example, an alarm sound for a specified time when a signal is supplied from the microcomputer (12).

Further, the monitoring device of the present example is provided with an infrared detector and a controller including an infrared light emitting element and a light receiving element for automatically controlling the power supply on the transmitting side. That is, a video camera (4a), a modulator (5a) and a transmitter (6a)
An infrared detector (21a) for detecting intrusion of a person into the first transmitter, and a controller (22a) for controlling the power of the first transmitter in accordance with the output of the detector (21a). An infrared detector (21b) for detecting intrusion of a person into a second transmitter comprising a video camera (4b), a modulator (5b) and a transmitter (6b);
A controller (22b) for controlling the power of the second transmitter in accordance with the output of 1b) is provided, and a third transmitter comprising a video camera (4c), a modulator (5c) and a transmitter (6c) is provided with a controller. Infrared detector (21
c) and a controller (22c) for controlling the power of the third transmitter according to the output of the detector (21c), and the video camera (4d) is connected to a fourth transmitter comprising a modulator (5d). Infrared detector to detect human intrusion (21d)
And a controller (22d) for controlling the power of the fourth transmitter according to the output of the detector (21d).

In addition, the receiving side responds to the on / off control signal from the transmitting side, and the power source of the receiving side, for example, a receiver (9a), a television receiver (11), a channel scan circuit (13), a monitor television (18) , A controller (23) for controlling a power supply such as a VTR (19) is provided.

Then, the intrusion of a person, for example, an infrared detector (21
When the signal is detected in a), a control signal for turning on the power is supplied from the controller (22a) to the first transmitter in response to the detection output, and the power of the first transmitter is turned on. Next, the controller (22a) is the controller (23) on the receiving side.
To the controller (2
3) responds to this by supplying a control signal for turning on the power to the receiver (9d) and the like to turn on the power.

As a result, the power of the receiver is turned on later than that of the transmitter, so that the transmission frequency at the time of reception can be reliably acquired.

Further, when the person no longer exists within the irradiation range of the infrared detector (21a), the detection output from the infrared detector (21a) to the controller (22a) disappears. Then, the controller (22a) transmits this to the controller (23) on the receiving side, turns off the power of the receiver (9d) and the like, and then turns off the power of the first transmitter. As a result, the transmitter side is turned off later than the receiver side, so that the receiver side erroneously determines that the transmission level has dropped, raises the AGC to full gain, and does not work to receive. No sound is generated.

 The same applies to the second to fourth transmitters.

As described above, in this embodiment, the controllers (22a) to (22d) are provided on the transmitter side, and the controller (23) is provided on the receiver side. Is turned on, and at the end of transmission, the power of the receiver is turned off and then the transmitter is turned off, so that the transmission frequency at the time of reception can be reliably pulled in and the unpleasant sound at the time of off can be eliminated. it can.

In addition, the video signal of the monitoring place photographed by the four video cameras (4a) to (4d) by one monitor television (18) can be monitored well. That is, the channel scan circuit (13) for supplying a video signal to the monitor television (18) has four channels corresponding to the four video cameras (4a) to (4d) according to a command from the channel switching circuit (14). Is automatically switched at predetermined intervals, and the motion detection circuit (17) detects whether there is any motion at the monitoring location of each channel that switches at predetermined intervals. It can be seen from the motion detection signal of the circuit (17). When the motion detection signal is output, the channel switching circuit (14) instructs the tuner (15) to demodulate the channel in which the change has occurred for a predetermined time. The video from the TV camera at the surveillance location where the alarm occurred is automatically displayed for a predetermined time. The video signal and the motion detection signal are also supplied to the VTR (19), and the recording of the video signal is performed for a predetermined time by the supply of the motion detection signal, so that the recording at the changed monitoring location is automatically performed. . In addition, VTR
Instead of (19), a hard copy device such as a video printer may be connected to take out the video at the changed monitoring location as a hard copy. Also, when the motion detection circuit (17) outputs a motion detection signal, a signal is supplied from the microcomputer (12) to the alarm device (20) to emit an alarm sound, so that the monitoring location has changed. Sometimes, a warning sound can alert the observer of the change. Instead of issuing an alarm as the alarm (20), a lamp or the like may be flashed to notify the change, or a change in the monitoring place may be transmitted to a remote place using a telephone line together with the channel information.

In this embodiment, a plurality of video cameras (4a) to (4d) can be connected to one monitor television (18) via one coaxial cable (1). There is no need to provide a transmission line up to the monitor television (18), and it can be configured with a small number of transmission lines. The first, second and third video cameras (4a), (4b) and (4c) and the alarm (20) are composed of transmitters (6a) to (6d) and receivers (9a) to (9d). There is no need to connect with a cable for wireless transmission between the camera and the camera, so that the video camera and the alarm can be easily arranged. Also, such a receiver (9a) ~
(9c), the signal is transmitted to the nearby coaxial cable (1). Therefore, the receivers (9a) to (9c) are provided near the monitor television (18) and the receivers (9a) to (9a) Compared with the case where the reception signal of 9c) is directly supplied to the channel scan circuit (13), the transmission signal may be a weak signal, the load on each device is small, and interference of the transmission signal can be prevented.
Further, the coaxial cable (1) can also be laid in a place where there is no change in appearance such as under the ceiling. Instead of performing wireless transmission, a direct connection may be made in the same manner as in the fourth video camera (4d), and may be appropriately selected depending on the grounding location.

[Effect of the invention]

As described above, according to the present invention, a control means for controlling the power of the transmitter and the receiver is provided, the power of the transmitter is turned on after starting the transmission, and then the power of the receiver is turned on. Since the transmitter is turned off after turning off the power, the transmission frequency can be reliably pulled in by the receiver at the start of transmission, and the generation of harsh sound of the receiver at the end of transmission can be prevented. And stable reception becomes possible.

[Brief description of the drawings]

The drawing is a configuration diagram showing an embodiment of the present invention. (4a) to (4d) are video cameras, (5a) to (5d) are modulators, (6a) to (6c) are transmitters, (9b) is receivers, (11) is television receivers, (13) Is a channel scan circuit, (21a) to (21d) are infrared detectors,
(22a) to (22d) and (23) are controllers.

Continuation of the front page (56) References JP-A-60-254398 (JP, A) JP-A-51-59226 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] 1. A detecting means for detecting an intruder, a surveillance camera for photographing a surveillance location, a transmitter for modulating an image of the surveillance camera at a predetermined transmission frequency and transmitting the same, and according to an output of the detecting means. First control means for controlling power of the transmitter and transmitting power control information via the transmitter, an automatic frequency tuning circuit for tuning to a transmission frequency of the transmitter, and transmission of the transmitter. A receiver for receiving the video and the power control information from the transmitter, comprising: an AGC circuit for controlling a gain according to a level; and controlling a power of the receiver according to the received power control information. And a second control unit that performs a transmission start when a detection output from the detection unit is obtained.
The first control means transmits the power control information after turning on the power of the transmitter, and the second control means turns on the power of the receiver when the power control information is received. At the end of transmission when the detection output from the detection means cannot be obtained, the first control means transmits the power control information to the second control means,
A monitoring device, wherein the power of the transmitter is turned off after the power of the receiver is turned off by the second control means.