JP2004240799A - Surveillance camera system with dummy light emission function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surveillance camera system with a dummy light emission function that is small in power source capacity, shape and the like and can prevent stroboscopic imaging from being identified as such. <P>SOLUTION: At imaging, in addition to light emission timing of a strobe (flash generator) 20, the strobe 20 is actuated for dummy light emission in a dummy light emission pattern timed differently from the light emission timing. An intruder misidentifies a series of dummy light emissions simply as threatening strobe light emissions and fails to notice the stroboscopic imaging during the dummy light emissions, so that the imaging by a surveillance camera 10 can be kept from being identified by the intruder. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for monitoring the inside of a detection area of a building such as a general house or a factory with a monitoring camera, and more particularly to a monitoring camera system that does not allow an intruder to recognize the flash shooting even when shooting with a flash (flash generator). About.
[0002]
[Prior art]
In a conventional surveillance camera system, a halogen light or the like is often used as auxiliary lighting during shooting in order to reliably capture an image of an intruder who has entered the detection area because the illuminance is low mainly at night. Lighting such as this halogen light is also used for threatening purposes. In an environment where power cannot be supplied from the outside, it is necessary to mount a power supply inside the system equipment and supply power from it.However, in order to turn on lighting such as halogen lights with the built-in power supply, the power supply capacity and external shape etc. There is a problem that it becomes very large and does not have realistic commerciality.
[0003]
On the other hand, in a surveillance camera system, it is also known to use a strobe to supplementally illuminate a detection area at the time of shooting (for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-159535
[Problems to be solved by the invention]
In order to solve the problem that the power supply capacity and external shape become large with the illumination such as the halogen light at the time of photographing, a strobe (flash generator) incorporated in a silver halide camera, a digital camera, or the like having a small power supply capacity or external shape. It is conceivable to use.
However, unlike lighting such as halogen lights, which are recognized as intimidating lighting for intruders, strobe lighting recognizes the presence of a surveillance camera because the flashlight recognizes that the intruder was shot with flash. Problems such as removal and destruction of the surveillance camera will occur.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a surveillance camera system which solves the above-mentioned problems and has a dummy light emission function which has a small power supply capacity, an external shape, and the like, and does not recognize flash photography.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a surveillance camera system having a dummy light emitting function according to the present invention includes a human body detector that detects a human body that has entered a detection area, and a surveillance camera that captures an image of the detection area when a human body is detected. And a flash generator that emits flash toward the detection area, and a recording unit that records a still image captured by the monitoring camera, in addition to the light emission timing of the flash generator at the time of shooting, An emission control unit is provided for controlling the flash generator to emit dummy light in a dummy emission pattern at a timing different from the emission timing.
[0008]
According to this configuration, in addition to the light emission timing of the flash generator (strobe) at the time of shooting, the strobe emits dummy light with a dummy light emission pattern at a timing different from this light emission timing, so that a series of dummy light emission is merely intimidated to the intruder. It is possible to make the intruder not recognize the flash shooting in the dummy flash and not recognize the intruder as having been shot by the surveillance camera.
[0009]
Preferably, the light emission control unit causes the flash generator (strobe) to emit dummy light in a dummy light emission pattern exemplified in the following (1) to (4). That is, (1) a dummy light emission pattern having the same light emission intensity as that at the time of shooting at a constant light emission interval, and (2) the light emission intensity is changed at a constant light emission interval, and the light emission intensity is gradually increased from the start of light emission. (3) changing the light emission interval and the light emission intensity gradually from the start of light emission, gradually changing the light emission intensity from the short period to the long period, and increasing the light emission intensity, taking the light emission intensity as the peak. A dummy light emission pattern that gradually changes from a long period to a short period and lowers the light emission intensity so that the light emission at the time has the longest period and the light emission intensity peaks, (4) the light emission interval and the light emission intensity change randomly This is a dummy light emission pattern to be performed. Therefore, the dummy light emission patterns (1) to (4) make it difficult for the intruder to recognize the shooting by the surveillance camera because the intruder does not notice the flash shooting in the dummy light emission.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view schematically showing an optical configuration in an installed state of a surveillance camera system having a dummy light emitting function according to a first embodiment of the present invention, and FIG. 2 is a block diagram showing an electric circuit of the present system. is there. As shown in FIG. 1, the present system is attached to an outer wall surface W of a building such as a general house or a factory, and monitors an intruder illegally entering a detection area A outside the building with a monitoring camera. The present system includes a human body detector 1 that detects a human body H that has entered the detection area A, a monitoring camera 10 that captures the detection area A when the human body H is detected, and a flash toward the detection area A. An electronic flash (flash generator) 20 is provided. When a human body H is detected mainly at night, the monitoring camera 10 performs flash photography of the detection area A using this as a trigger.
[0011]
As shown in FIG. 2, an image signal captured by the monitoring camera 10 is processed by an image processing circuit 12 to obtain a still image. This still image is recorded in the recording unit (frame memory) 34. In this system, each unit is driven by a power supply unit 33 having, for example, a DC power supply 32, and a control unit 30 such as a CPU controls the entire system to operate the surveillance camera 10 and to emit a strobe light by a strobe light emitting circuit. 21 is controlled.
[0012]
The human body detector 1 in FIG. 1 is, for example, of a passive infrared (PIR) type, and includes an infrared detecting element 2 formed of a pyroelectric element in a case 41. The detection element 2 has a detection area A set by an optical system 51 such as a Fresnel lens or a mirror mounted on the case 41 located in front of the detection element 2. Infrared energy radiated from the human body H or the like in each detection area A is condensed by the optical system 51 and is incident on the corresponding detection element 2, and the human body H is detected by the human body detection circuit 5 of FIG. Is detected. Here, the human body H is an intruder into the detection area A.
[0013]
FIG. 3 shows a configuration of a strobe light emitting circuit 21 controlled by the control unit 30 to emit a strobe 20 such as a strobe discharge tube. The strobe light emitting circuit 21 has a booster circuit 23 for boosting the voltage of the DC power supply 32 in the power supply unit 33 and a variable capacitor C for causing the strobe 20 to emit light with a predetermined light emission intensity. A variable capacity type capacitor VC for charging the applied voltage, a trigger circuit 24 for discharging the capacitor VC through the strobe 20, and an emission control unit 25 for controlling the entire emission of the strobe 20 are provided. The light emission control unit 25 has a dummy light emission control unit 26. In addition to the light emission timing of the strobe 20 at the time of shooting by the monitoring camera 10, the dummy light emission control unit 26 uses a dummy light emission pattern of a timing different from this light emission timing. The strobe 20 is controlled to emit dummy light.
[0014]
The capacitor VC changes the capacitor capacitance C by, for example, rotating an axis to adjust the facing area and distance of the electrode plates, and sends a control signal from the dummy light emission control unit 26 to the capacitor VC and the booster circuit 23. Output to change the light emission intensity of the strobe 20 according to the pattern.
When the light emission intensity is the same as the light emission intensity at the time of photographing at a constant light emission interval as in a first example of a dummy light emission pattern described later, a fixed-capacity capacitor having a constant capacitor capacitance C may be used. .
[0015]
The strobe 20 is, for example, one that is incorporated in a silver halide camera, a digital camera, or the like, and one or more strobes are used according to the size of the detection area A. As a result, the power supply capacity, outer shape, and the like can be reduced as compared with the conventional case, such as a halogen light. Also, since it is a commercial product, the cost of the surveillance camera system can be reduced. In this example, the same flash is used to emit light during shooting and dummy light emission. However, separate flashes for shooting and dummy light emission may be used.
[0016]
Hereinafter, the dummy light emission operation in the present system will be described.
First, when the human body detector 1 detects the human body H, the monitoring camera 10 uses the flash 20 to perform flash photography of the detection area A using the trigger as a trigger. Before and after the light emission timing of the strobe 20 at the time of this photographing, the dummy light emission control unit 26 makes the strobe 20 emit dummy light at a constant light emission interval with a dummy light emission pattern having the same light emission intensity as that at the time of photographing. FIG. 4 shows a first example of the dummy light emitting pattern.
[0017]
That is, in the strobe light emitting circuit 21, the capacitor VC is charged in advance to a constant voltage by the power supply unit 33, a control signal is output from the dummy light emitting control unit 26 in accordance with the dummy light emitting pattern, and a trigger is generated in accordance with the light emitting interval. When a trigger voltage is applied by the circuit 24, the capacitor VC charged to a constant voltage is discharged through the strobe 20, which causes the strobe 20 to emit strobe light. After discharging, the capacitor VC is charged and discharged in the same manner as described above, and this operation is repeated thereafter. This dummy light emission pattern is performed so that the flash 20 emits light before and after the light emission of the flash 20 in synchronization with the photographing.
[0018]
In this way, in addition to the emission timing of the strobe 20 during shooting, the strobe 20 is dummy-emitted with a dummy emission pattern at a timing different from this emission timing. Thus, it is possible to prevent the intruder from recognizing that the surveillance camera 10 has been photographed without noticing the flash photography in the dummy light emission. Thus, problems such as removal and destruction of the monitoring camera 10 do not occur.
[0019]
Hereinafter, the second to fourth examples of the dummy light emitting pattern will be described.
In the second to fourth examples, a program for a dummy light emission pattern is prepared in advance and stored in the dummy light emission control unit 26. The dummy light emission control unit 26 sends a control signal to the trigger circuit 24 and the capacitor VC according to each program. And the output to the booster circuit 23 to make the strobe 20 emit light according to the pattern.
[0020]
Second Example of Dummy Light Emission Pattern As shown in FIG. 5A, the light emission intensity is changed at a constant light emission interval, the light emission intensity is gradually increased from the start of light emission, and the light emission intensity at the time of shooting is peaked. This is a dummy light emission pattern for gradually lowering the light emission intensity.
This makes it possible for the intruder to mistake the series of dummy flashes as strobe flashes just for intimidation and not to notice strobe shooting, and sets the maximum intensity at the time of flash shooting when the DC power supply 32 is exhausted, and sets the emission intensity before and after that. , The consumption of the DC power supply 32 can be reduced.
[0021]
Third Example of Dummy Light-Emitting Pattern In the third example, as shown in FIG. 5B, the light-emission interval and the light-emission intensity are changed, and the light-emission intensity is gradually increased from the short period to the long period and the light-emission intensity is increased. This is a dummy light emission pattern in which light emission at the time of shooting has the longest period and the light emission intensity has a peak, and the light emission intensity is gradually changed from a long period to a short period and the light emission intensity is reduced.
This makes it possible for the intruder to mistake the series of dummy flashes as strobe flashes simply for intimidation and not to notice strobe shooting, and since the flashing cycle during shooting is the longest, the capacitor immediately before the maximum intensity of strobe shooting is used. The charging time can be earned.
[0022]
Fourth Example of Dummy Light Emission Pattern As shown in FIG. 5C, a fourth example is a dummy light emission pattern in which the light emission interval and light emission intensity are changed at random. This random change can be made, for example, through a shift register and a logic circuit representing a random number.
This makes it possible to create a pattern that makes the intruder emit a series of dummy flashes merely as a strobe light for intimidation and misleads them as not being intentional, so that it is possible to make the flash shooting less noticeable.
[0023]
In the first to fourth examples of the dummy light emission pattern, the flash photography is performed almost in the middle of the dummy light emission pattern. However, the present invention is not limited to these examples. Photographing may be performed.
[0024]
FIG. 6 is a side view schematically illustrating an optical configuration of a monitoring camera system having a dummy light emitting function according to a first example of the second embodiment in an installed state.
In the second embodiment, unlike the first embodiment, detection areas A1 and A2 are provided. In the distant detection area A1, the dummy light emission control unit 26 does not perform strobe photographing only with a threat but emits light from the strobe 20. Control is performed to reduce the intensity and perform flash photography in the close detection area A2 to increase the emission intensity of the flash 20.
[0025]
The human body detector 1 is of a passive infrared (PIR) type as in FIG. 1, but a pair of infrared detection elements 2 and 3 made of a pyroelectric element are housed in a case 41. Each of the detection elements 2 and 3 sets detection areas A1 and A2 by optical systems 51 and 52 such as Fresnel lenses and mirrors mounted on the case 41 at the front thereof. Infrared energy radiated from the human body H or the like in each of the detection areas A1 and A2 is condensed by the optical systems 51 and 52 and is incident on the corresponding detection elements 2 and 3, whereby the human body H is detected. The other configuration is the same as that of the first embodiment except that the dummy light emission control unit 26 performs the above-described strobe control.
[0026]
This makes it possible for the intruder to mistake the series of dummy light emission as strobe light emission for intimidation and not to notice strobe shooting, and also allows the surveillance camera 10 to shoot only intruders approaching a certain level or more with the surveillance camera 10.
Note that the detection area may be three or more areas instead of the two areas A1 and A2.
[0027]
Further, in the second example of the second embodiment, unlike the first example, the dummy light emission control unit 26 increases the light emission intensity of the strobe 20 in the distant detection area A1 to perform flash photography, and emits light in the close detection area A2. Control for strobe shooting with smaller. Other configurations are the same as in the first example.
This makes it possible for the intruder to mistake the series of dummy flashes as strobe flashes for intimidation and not to notice the flash shooting, and also to perform flash shooting twice or more in the detection areas A1 and A2. The probability of catching can be increased.
In the second example, a light control function of a camera that adjusts the light emission intensity of the strobe 20 according to the shooting distance may be used.
[0028]
Next, a third embodiment will be described.
In the third embodiment, unlike the first embodiment, in addition to the strobe 20, in addition to the white light emitting diode (LED) that emits dummy light toward the detection area A and the light emission timing of the strobe 20 during photographing, A light emission control unit that controls the light emitting diode to emit dummy light with a dummy light emission pattern at a timing different from the light emission timing. That is, photographing is performed by the strobe 20, and dummy light emission is performed by the light emitting diode (LED). Other configurations are the same as those of the first embodiment.
This makes it possible for the intruder to erroneously recognize a series of dummy flashes as strobe flashes for intimidation and not to notice flash shooting, and also reduces the load on the strobe 20.
[0029]
In each of the above embodiments, the human body detector 1 is a passive infrared (PIR) system. However, an AIR system which projects near infrared rays as a detection wave, receives near infrared rays reflected from the object, and detects the object. May be. It is also possible to use an ultrasonic or radio active sensor having a transmitting element and a receiving element that transmit and receive ultrasonic waves or radio waves as detection waves, and furthermore, by detecting disturbance of electromagnetic waves, A human body may be detected by a switch or the like that is linked to opening and closing of a physical shielding unit that separates inside and outside.
[0030]
【The invention's effect】
As described above, according to the present invention, in addition to the emission timing of the strobe (flash generator) at the time of shooting, the strobe emits dummy light with a dummy emission pattern at a timing different from this emission timing. The dummy light emission can simply be mistaken for a strobe light emission for intimidation, so that the user does not notice the flash photography in the dummy light emission and does not make an intruder recognize that the photographing was performed by the surveillance camera.
[Brief description of the drawings]
FIG. 1 is a side view schematically showing an optical configuration of an installed state of a monitoring camera system according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing an electric circuit of the surveillance camera system of the embodiment.
FIG. 3 is a block diagram showing a strobe light emitting circuit of the embodiment.
FIG. 4 is a diagram showing a first example of a dummy light emitting pattern.
FIGS. 5A to 5C are diagrams showing second to fourth examples of dummy light emitting patterns.
FIG. 6 is a side view schematically illustrating an optical configuration of a monitoring camera system according to a second embodiment in an installed state.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Human body detector, 10 ... Surveillance camera, 20 ... Strobe (flash generator), 21 ... Strobe light emission circuit, 25 ... Light emission control part, 26 ... Dummy light emission control part, 34 ... Recording part, A, A1, A2 ... Detection area.

Claims (6)

A human body detector that detects a human body that has entered the detection area, a surveillance camera that shoots the detection area when a human body is detected, a flash generator that emits a flash toward the detection area, and a still image captured by the monitoring camera A surveillance camera system comprising a recording unit that records an image,
A surveillance camera system having a dummy light emission function including a light emission control unit that controls the flash light generator to emit dummy light with a dummy light emission pattern at a timing different from the light emission timing in addition to the light emission timing of the flash light generator at the time of shooting . In claim 1,
A surveillance camera system having a dummy light emission function for causing the flash generator to emit dummy light with a dummy light emission pattern having the same light emission intensity as that at the time of shooting at a constant light emission interval. In claim 1,
The light emission control unit changes the light emission intensity at a fixed light emission interval, gradually increases the light emission intensity from the start of light emission, and sets a dummy light emission pattern that gradually reduces the light emission intensity with the light emission intensity at the time of shooting as a peak, A surveillance camera system having a dummy light emission function for causing a dummy light emission. In claim 1,
The light emission control unit changes the light emission interval and light emission intensity, gradually changes from a short period to a long period from the start of light emission, and increases the light emission intensity. The light emission during shooting has the longest period and the light emission intensity has a peak. A surveillance camera system having a dummy light emission function for causing a flash generator to emit dummy light in a dummy light emission pattern that gradually changes from a long cycle to a short cycle and reduces the light emission intensity. In claim 1,
A surveillance camera system having a dummy light emission function for causing the flash generator to emit dummy light with a dummy light emission pattern in which a light emission interval and a light emission intensity are randomly changed. A human body detector that detects a human body that has entered the detection area, a surveillance camera that shoots the detection area when a human body is detected, a flash generator that emits a flash toward the detection area, and a still image captured by the monitoring camera A surveillance camera system comprising a recording unit that records an image,
A light-emitting diode that emits dummy light toward the detection area,
A surveillance camera system having a dummy light emission function including: a light emission control unit that controls the light emitting diode to emit dummy light with a dummy light emission pattern at a timing different from the light emission timing in addition to the light emission timing of the flash generator during shooting. .

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