Merchandise display window surveillance system - uses laser source which transmits flat beam through window which is detected by receiver in corner of pane

摘要

The window surveillance system uses a laser luminous source (2) which emits a light beam (3) which is only slightly absorbed by the material from which the window is made. The beam (3) is captured by a receiver (12) after it has been in contact with the window. An alarm (15) is actuated by the receiver when a certain step value has been exceeded. The system has means for introducing into the thickness of the window a flat beam whose thickness is approx. equal to the window thickness. The receiver (12) receives the flat beam after it has swept the whole of the interior of the window pane. The laser luminous source (2) is connected to the window by fibre optics fixed to the glass. The beam being introduced at a corner of the window. The receiver is arranged and fixed at an opposite corner of the window to which the beam is introduced.