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(11) | EP 0 135 362 A3 |
(12) | EUROPEAN PATENT APPLICATION |
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(54) | Optical smoke detectors |
(57) A flash reflector (60) for maximising the intensity of light passing into an air
sampling chamber (70) of a smoke detector which enables a reduction in power requirements
for the light source. The reflector (60) includes a concave reflection element (61)
to focus light from each infinitesimal cross-sectional element of the arc of ionized
gas in a flash tube (62), the light output from the whole length of the tube which
is optionally of U-shape being focused into the central region (72) of the sampling
chamber. |