JPH08273063A - Infrared type burglar warning device - Google Patents

Abstract

PURPOSE: To prevent malfunction even when intensive disturbance light is made incident and to keep an original moving human body detecting function by driving an auxiliary beam system by detecting that the disturbance light such as sunlight is made incident on a first light receiver. CONSTITUTION: The light receiving signal of a first light receiver R1 is inputted through an integration circuit 24 and an amplifier circuit 25 to a saturation detection circuit 26. This saturation detection circuit 26 detects that a pulse modulated signal is saturated with a DC signal at a high level since intensive external light such as sunlight is superimposed on an original pulse modulated signal. When a saturation detecting signal is outputted, a floor control part 27 commands the light emission start of a second light emitter T2, a driving circuit 28 is activated according to this command signal and the pulse modulated light emission of the second light emitter T2 is performed. In this case, a signal processing part 21 and the flood control part 27 are provided with a microcomputer. Thus, when the direct light or reflected light of sunlight is made incident on the first light receiver R1 and detected by the saturation detection circuit 26, the auxiliary beam system is driven and the moving human body detecting function is maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared security alarm device.

[0002]

2. Description of the Related Art FIG. 3 shows a block diagram of a conventional example. The projectors 1a of the infrared projector 1 are provided at both ends of the linear warning area.
And the light receiver 2a of the infrared light receiver 2 are installed with their optical axes aligned with each other. Then, the projector 1a
Is composed of a light emitting element such as an infrared light emitting diode and a light projecting lens for forming a light projecting beam. The light emitting element is driven by the light projector driving section 1b at a predetermined frequency, for example, 8
By being driven to emit light at 00H _Z , an infrared beam composed of pulse-modulated light is emitted.

On the other hand, in the light receiving section 2, a light receiver 2a including a light receiving lens and a light receiving element such as a photodiode receives an infrared beam and outputs an electric signal corresponding to the amount of received infrared light. After being amplified by the amplifier circuit 2b, it is converted into a signal corresponding to the level of the received signal by only the pulse-modulated light in the detection circuit 2c, and the signal discrimination circuit determines whether or not this signal level is below the set detection level. Then, when the infrared beam from the projector 1a is blocked by an illegal intruder and the received signal level becomes lower than the set detection level, a detection signal is output and the alarm generator 2e is driven to output an alarm signal to detect illegal intrusion. It is configured to notify that there was.

When this type of infrared security alarm device is installed outdoors, it is easy to align the optical axis during installation work.
The allowable angle of incidence (viewing angle) on the light receiver is usually ±
It has a spread of 3 ° to 5 °. Therefore, when strong ambient light such as sunlight enters from the direction of 5 ° with respect to the optical axis, there is a drawback that the moving body detection function malfunctions due to the ambient light.

Conventionally, in order to simplify wiring work,
A system is adopted in which only the power source is connected to the projector side, and the moving human body detection information is transmitted only from the receiver side to the central control panel.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention is an infrared security alarm device capable of preventing malfunction even when a strong disturbance light such as sunlight is incident and maintaining the original function of detecting a moving human body. I will provide a.

The direct light of sunlight or the reflected light from the glass of a building or the like usually passes through in 15 to 20 minutes and returns to the original state, but if the saturation phenomenon due to strong ambient light lasts for 25 minutes or more, some abnormality will occur. It is predicted that it has occurred. The present invention provides an infrared security alarm device capable of detecting such an abnormality.

[0008]

SUMMARY OF THE INVENTION An infrared security alarm system according to the present invention comprises a main beam system including a first light projector and a first light receiver for receiving an infrared beam emitted by the light projector.
An auxiliary beam consisting of a second light emitter arranged in the vicinity of the first light receiver and a second light receiver arranged in the vicinity of the first light emitter for receiving the infrared beam emitted from the light emitter. A system, a saturation detection unit that detects that ambient light such as sunlight is incident on the first light receiver, and a switching unit that drives the auxiliary beam system according to a detection signal of the saturation detection unit. And

In order to use the transmission system for the central control panel or the like, which has been conventionally provided, as it is, a memory for temporarily storing the light-shielding detection information by the auxiliary beam system is provided, and after the disturbance disturbance of the main beam system is eliminated. It is preferable that the information stored in the memory is transmitted to the light shielding detection information processing system of the main beam system.

During the driving time of the auxiliary beam system, in order to suppress the power consumption of the main beam system, the power supply of the first projector is temporarily turned off by the light receiving signal of the second light receiver of the auxiliary beam system. Is preferred.

Further, in order to utilize the auxiliary beam system of the present invention for the optical axis adjustment work during installation work, a manual changeover switch for manually driving the auxiliary beam system and the received light intensity of the second light receiver are displayed. It is preferable to provide a level meter for controlling.

Further, the infrared type security alarm system of the present invention includes the main beam system, the auxiliary beam system, the saturation detecting means, the electronic timepiece, and the time zone in which the saturation detecting means issues a detection signal. The present invention can also be configured by the invention having a saturation time zone storage memory to be stored and a light projecting means of the second light projector for operating the auxiliary beam system according to read information from the saturation time zone storage memory.

Furthermore, the infrared type security alarm device of the present invention provides an alarm when the main beam system, the saturation detection means, a timer, and the output time of the saturation detection signal exceed the set value of the timer. It can also be configured by the invention having means for outputting In this case, the set value of the timer is such that the saturation time due to the operation of the sun is usually 15 to 20 minutes, so that the normal saturation time is not included, for example, 2
It is set to 5 minutes or more.

[0014]

When the direct light or reflected light of sunlight enters the first light receiver and the saturation detecting means detects it, the auxiliary beam system is driven, and the auxiliary beam system maintains the moving human body detecting function.

When the saturation detecting means detects that the disturbance light is no longer incident, the driving of the main beam system is restarted and the auxiliary beam system is stopped. Since the main beam system and the auxiliary beam system have opposite directions of light rays, the sunlight is the first
The second light receiver is backed by the sun rays when it is incident on the second light receiver, and therefore the incident light beam to the second light receiver is not likely to malfunction due to sunlight or the like.

In the invention described in the fifth aspect, the auxiliary beam system is driven by the information in the saturation time zone storage memory even if there is no detection signal from the saturation detection means. According to the invention described in the sixth aspect, it is possible to detect a tamper (prank act) such as irradiating a headlight, a laser pointer or the like of an automobile toward the first light receiver as an abnormality.

[0017]

1 is a block circuit diagram of an embodiment of the present invention. The first housing 10 and the second housing 20 are installed with a predetermined distance therebetween, and the first projector ₁₀ and the second light receiver R ₂ are arranged in the first housing 10, and the second housing A first light receiver R ₁ and a second light projector T
_Two are arranged. The infrared light beam B ₁ emitted by the first light projector T ₁ and the infrared light beam B ₂ emitted by the second light projector T ₂ are parallel and close to each other, and the light traveling directions are opposite to each other.

[0018] To explain the first housing 10, the first light projector T _1, for example 800H _Z by the drive circuit 11
The light emission control unit 12 controls on / off of light emission. The first light receiver R ₂ receives light when sunlight is incident on the _first light receiver R ₁ and the light reception signal is saturated, or during the optical axis adjustment work during installation, or the like. The signal processing unit 13
The received light signal is A / D converted, and the presence / absence of light reception and the detection of a moving human body due to light blocking during light reception are determined, and the content of the light-modulated signal is decoded. The reception level during light reception is displayed on the display unit 14. The memory 15 is activated when the signal processing unit 13 detects the start of light reception. This memory 1
The contents of 5 will be described later. The light projecting unit 12, the signal processing unit 13, and the memory 15 can be implemented using a microcomputer.

The first light receiver R in the second housing 20
The received light signal ₁ is passed through an AGC (automatic gain control) circuit and an amplifier circuit and then input to the signal processing unit 21. The signal processing unit 21 performs A / D conversion on the received light signal, determines the detection of a moving human body due to light blocking during light reception, and when it is determined that the human body is detected, operates the output circuit 22 to output an alarm signal.
The reception level during light reception is displayed on the display 23.

On the other hand, the light reception signal of the _first light receiver R ₁ is input to the saturation detection circuit 26 via the integration circuit 24 and the amplification circuit 25. The saturation detection circuit detects that the pulse-modulated signal is saturated with a high-level DC signal because strong extraneous light such as sunlight is superimposed on the original pulse-modulated light. When the saturation detection signal is output, the light projecting control unit 27 commands the start of light emission of the second light emitter T ₂ , and the drive circuit 28 is activated in accordance with this command signal to cause the second light emitter T ₂ to undergo pulse modulation light emission. Let The signal processing unit 21 and the light emission control unit 27 can be implemented using a microcomputer.

FIG. 2 shows an embodiment of a flow chart of control by a microcomputer. Normally, this control program is preferably provided in the memory 15 in the first housing 10, but may be provided in the second housing. The above-mentioned infrared beams B ₁ and B ₂ can be code-modulated and used for transmitting and receiving a signal between both housings, and other communication means such as electromagnetic waves may be used. In this flow chart, A represents the first housing side and B represents the second housing side. As shown in the legend, in the rectangular frame representing the execution content, the vertical image of the one by A is made into a double line and by A. B is distinguished.

In this embodiment, only the first receiver side B has a transmission circuit to the central control panel or the security company, and the first received light signal is saturated by sunlight, for example, 10
Even if the alarm is delayed for up to 15 minutes, it is suitable for the application in which it is sufficient if only the presence or absence of passage of the moving human body is accurate.

Next, a technique of using the auxiliary beam system of the present invention for the optical axis adjusting work during the installation work will be described.
An operator attaches to both the first housing 10 and the second housing 20 to operate the manual switch (not shown) so that the first and second projectors T ₁ and T ₂ are always in a light emitting state. Under this condition, both workers visually check the beams B ₁ , B 2.
_After the optical axis of ₂ is made to face the receiver on the other side, a fine adjustment mechanism may be used to finely adjust the reception level at hand to the maximum.

Further, the auxiliary beam system of the present invention can be used for detection and countermeasures against tampering (tampering). Tamper switches 16 and 29 that are turned on and off in synchronization with the opening of the housing cover are provided in each housing. The tamper signal of the second housing is immediately transmitted to the central control panel and the security company through the tamper output circuit 30, and is also transmitted to the first housing side by the light projecting control unit 27 to take necessary measures. On the other hand, when the tamper signal of the first housing is output, it is transmitted to the second housing by using the main beam system, and the signal processing unit 21 discriminates this case, and the tamper signal of the second housing is output. The tamper output circuit 30 is operated in the same manner as when the tamper output is performed.

As another embodiment of the present invention, an electronic timepiece is added to the microcomputer on the side of the first light receiver R _{1, and the} time zone in which the saturation detection signal is emitted by sunlight is stored in the memory of the microcomputer together with the date. Then, the time zones of tomorrow and the day after tomorrow can be predicted from the latest time zone, and the auxiliary beam system can be positively operated based on the predicted time zone without waiting for the detection signal from the saturation detection circuit 26. . This configuration can be implemented by software of a microcomputer built in the second housing.

As another embodiment of the present invention, time measurement is started by a timer from the rise time of the saturation detection circuit output, and when the time reaches a predetermined set value, for example, 30 minutes or more, an abnormal alarm is issued at the center. It can be configured to notify the control panel or the like. This timer can be implemented by counting clock pulses of an electronic timepiece or a microcomputer. This embodiment is useful for fault occurrence or tamper detection. This embodiment can also be carried out by the software of the microcomputer contained in the second housing.

[0027]

According to the present invention, when a sunbeam or the like is incident on the photodetector of the main beam system to cause a saturation phenomenon and the detection of an intruder becomes impossible, the optical path is immediately reversed. Since the correction beam system is activated and the intruder detection function is maintained, the undetectable time zone has disappeared. Further, it is possible to detect a continuous abnormal saturation state, which is not transient like sunlight incident.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing an embodiment of the present invention.

FIG. 2 is a flow chart for explaining the operation of the above embodiment.

FIG. 3 is a block diagram showing a conventional example.

[Explanation of symbols]

10 First housing 20 Second housing 26 Saturation detection circuit T ₁ First projector T ₂ Second projector R ₁ First receiver R ₂ 2 light receivers

Claims (6)

[Claims] 1. A main beam system comprising a first light projector and a first light receiver for receiving an infrared beam emitted from the light projector, and a second light projector arranged in the vicinity of the first light receiver. An auxiliary beam system including a second light receiver arranged in the vicinity of the first light projector for receiving the infrared beam emitted by the light projector, and disturbance light such as sunlight is incident on the first light receiver. An infrared crime prevention alarm device, comprising: saturation detection means for detecting the fact that the above has occurred, and switching means for driving the auxiliary beam system according to a detection signal of the saturation detection means. 2. A memory for temporarily storing light-shielding detection information by the auxiliary beam system is provided, and after the disturbance disturbance of the main beam system is resolved, the information stored in the memory is transmitted to the light-shielding detection information processing system of the main beam system. The infrared security alarm device according to claim 1, wherein the infrared security alarm device is configured as described above. 3. The infrared security alarm device according to claim 1, further comprising a switch for turning off the power supply to the first light projector in response to a light receiving signal from the second light receiver. 4. The infrared security alarm device according to claim 1, further comprising a manual changeover switch for manually driving the auxiliary beam system and a level meter for displaying a received light intensity of the second light receiver. 5. The main beam system, the auxiliary beam system, the saturation detection means, an electronic timepiece, a saturation time zone storage memory for storing the time zone in which the saturation detection means issues a detection signal, and An infrared security alarm device having a projection control means of the second projector for operating the auxiliary beam system in accordance with the read information from the saturation time zone storage memory. 6. An infrared security alarm device having the main beam system, the saturation detection means, a timer, and means for outputting an alarm when the output time of the saturation detection signal exceeds a set value of the timer. .