JPH0664157B2 - Anomaly detection device using optical fiber - Google Patents

Description

The present invention relates to a novel abnormality detecting device for detecting crime and disaster prevention abnormality using an optical fiber.

Conventionally, as an abnormality detecting device for detecting an abnormal situation such as intrusion or fire, a device in which a detector is attached to a necessary place in a security area and the detection signal is sent to an alarm device by an electric transmission means is often used. However, in the conventional device, electrical noise such as short circuit between wires, area or induction is picked up, and the detection range of the above sensor is limited. Therefore, if the security area is wide, many sensors must be installed. There were drawbacks such as not becoming.

The present invention has been made to solve the above-mentioned drawbacks, for example, coherent light from a laser light source device is transmitted to a plurality of detection areas set in a security area while being branched using an optical fiber, In the detection area, the coherent light is further branched into two paths, and these are made incident on two optical fibers laid in the detection area to form an interference fringe pattern behind the emission surface. By detecting the movement / change of the interference fringe pattern such as physical deformation of members, vibration, or temperature rise due to fire, etc., the influence of noise can be reduced and the occurrence of abnormal situations can be grasped with certainty. An object of the present invention is to provide an abnormality detection device using an optical fiber that can identify a detection area.

The present invention adopts the following means in order to solve the above problems.

The present invention provides a light source device that generates coherent light including laser light, a branching unit that branches the coherent light into two paths, a function of transmitting the coherent light, and a physical modification of a building member,
An abnormality detection means composed of at least one pair of optical fibers having a function of detecting vibration or temperature rise, a coupling means for merging light passing through the optical fibers into one path, and an interference fringe pattern formed by the coupling means. An alarm processing device comprising an interference fringe detection section for detecting and outputting a detection signal and an alarm section for comparing the detection signal with a preset reference pattern and outputting an alarm, the abnormality detecting means and the branch. Means and coupling means are used to form a plurality of detection areas by arranging them in parallel at a desired plurality of locations in the security area building, and the pair of optical fibers constituting the abnormality detection means surround the detection area. The interference fringe pattern is moved / changed by the abnormality detecting means for any abnormality of physical deformation, vibration or temperature rise of at least the building member in each of the detection areas. And detected, characterized by being arranged to emit an alarm.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an abnormality detecting device for an intruder or the like using an optical fiber according to an embodiment of the present invention, in which 1 is a laser light source device, and an optical system 1a such as a lens is provided at a rear stage. is doing. 2 is a single-mode or polarization-preserving type that has a function of transmitting coherent light and a function of detecting an increase in ambient temperature due to a small deformation of a building member such as a floor, ceiling, or wall of a building by an intruder or a fire. Optical fibers, 3 are branching devices for dividing the coherent light emitted from the laser light source device 1 and transmitted by the optical fiber 2 into two paths, and 4 are set at a plurality of places in the security area, and abnormality detection is required. Is a coupler for combining a pair of two optical fibers 2 laid in the detection area 4 and outputting the combined optical fiber 2 to one optical fiber 2, and 6 is generated by the coupler 5. It is an alarm processing device that detects an interference fringe pattern, determines its state, and issues an alarm.

The operation of the embodiment of the present invention will be described based on the above configuration.

First, two optical fibers 2 are laid in a sensitive area of a building in a security area, for example, in a detection area 4 provided on a wall near a window, a floor, a ceiling or the like so as not to hinder the resident's daily activities. Then, when an intruder or the like encounters, a slight deformation of the building member due to the walking or the like can be detected. The laser light emitted from the laser light source device 1 is incident on the optical fiber 2 through an optical system 1a such as a lens, is branched into two by a branching device 3, and is further branched into four and is provided in a detection area 4 1 It is incident on the pair of optical fibers 2.

The optical fibers 2 branched into two paths are joined by a coupler 5. Here, unless an abnormal situation such as an intruder occurs in the detection area 4, the interference fringe pattern formed in the coupler 5 does not move or change. On the other hand, if there is an intruder or the like, a relative minute deformation is caused between the positions of the pair of optical fibers 2 composed of the above-mentioned two fibers, and the movement / change of this pattern is caused by the optical fibers 2 to generate an alarm processing device. 6 is transmitted. The alarm processing device 6 detects minute deformations in the detection area 4, which are transmitted by different optical fibers 2, that is, movements / changes of the interference fringe pattern, and compares them with a preset reference to issue an alarm. For example, it is displayed by a buzzer, a lamp or the like to notify the occurrence of an abnormal situation such as an intruder.

As described above, according to the present invention, since all signals are transmitted using light as a medium, no special consideration is given to the environment even in a place where electromagnetic noise is difficult to use in the past, or where there is an explosive atmosphere. The anomaly detection method that can be used for is obtained, and the configuration in which multiple detection areas are arranged in parallel at any location using a branching device and a combiner makes it possible to use only one optical fiber in the non-detection area. It is possible to reduce the change, that is, the noise, which occurs at 1, and to supply the coherent light to a plurality of detection areas in parallel, so that it is possible to identify the abnormal detection area. Further, since a pair of optical fibers forming the abnormality detecting means are arranged so as to surround the detection area and are not buried, it is possible to detect an increase in the ambient temperature, and at the same time when an intruder or the like has an abnormality in crime prevention. Also, it is possible to detect anomalies in disaster prevention such as a fire, and it is particularly easy to lay it indoors and to maintain and repair it.

[Brief description of drawings]

FIG. 1 is a block diagram showing an abnormality detecting method for an intruder or the like using an optical fiber according to an embodiment of the present invention. 1 ... Laser light source device, 1a ... Optical components such as lens, 2 ...
Optical fiber, 3 ... Divider, 4 ... Sensing area, 5 ... Coupler,
6 ... Alarm processing device.

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Claims (1)

[Claims] 1. A light source device for generating coherent light including laser light, a branching means for branching the coherent light into two paths, a function for transmitting the coherent light, and a physical deformation and vibration of a building member. Alternatively, an abnormality detecting means composed of at least one pair of optical fibers having a function of detecting a temperature rise, a coupling means for merging light passing through the optical fibers into one path, and an interference fringe pattern formed by the coupling means are detected. And an alarm processing device comprising an interference fringe detecting section for outputting a detection signal and an alarm section for outputting an alarm by comparing the detection signal with a preset reference pattern, and the abnormality detecting means and the branching means. And a coupling means to form a plurality of detection areas in a desired plurality of locations in the security area building in parallel, and the pair of optical fibers constituting the abnormality detection means are the detection areas. It is arranged so as to surround, and at least an abnormality in physical deformation, vibration or temperature rise of at least a building member in each of the detection areas is detected as movement / change of the interference fringe pattern by the abnormality detection means, and an alarm is issued. An abnormality detection device using an optical fiber, which is configured to emit light.