| 摘要 |
An alarm system comprises plural movement PIR detector of which three such detectors are shown and designated by reference numerals 1, 2 and 3. An alarm control box (4) is connected to the movement detectors (1, 2 and 3) so as to receive an activation signal from a movement detector which has been actuated by movement from an intruder within its range. The control box is connected to an illumination controller (5) provided to energise lamps (6, 7, 8 and 9) intermittently once an alarm activation signal has been received by control box (4). The illumination controller is equipped to alternate the illumination of a lamp so that, upon receipt of a signal from control box designated for the energisation of a particular lamp, the lamp is first energised so as to illuminate it to a level which causes closure of the irises of the eyes of the intruder (but without permanent eye damage) and then de-energised so that illumination is near zero for sufficient time for iris recovery (e.g. a period of 6 seconds). Thereafter, the same lamp (or another lamp in response to detection of the intruder by another of the movement detectors) is illuminated (again) so as to close intruder's irises. In this way, the intruder's eyes are unable to acclimatise to the changing light conditions and his movement about the space addressed by the alarm system is seriously imparied.
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