| 摘要 |
PURPOSE:To enable the identification of an area causing abnormality capturing the generation of an abnormal situation accurately by a method wherein an interferring light from a laser light source is transmitted to a plurality of detection areas being branched using an optical fiber and made to enter two optical fibers installed in the detection areas to form an interference fringe pattern behind the incident surface, so that a rise in the temperature or the like due to physical deformation of building members under a contact pressure, fires or the like can be detected. CONSTITUTION:Two optical fibers 2 are installed in detection areas 4 such as a floor and ceiling in a security region to make any fine deformation of building members due to an invader or the like sensible. A laser light from a laser light source 1 enters the optical fibers 2 through an optical system 1a such as lens, branched into two with a branch 3 and then, into four to be incident to the optical fibers 2 in a pair in the detection area 4. The optical fibers 2 branched are put together with a coupler 5. Now, when any invader or the like is in the detection area 4, a relative fine deformation is caused between the positions of the two optical fibers 2 and the movement and changes of the pattern are transferred to an alarm processor 6 with the optical fibers 2 and compared with the preset reference to give an alarm. This is indicated with a buzzer, lamp or the like to notify of the generation of an abnormal situation. |
