| 摘要 |
An optical smoke detector has labyrinth members 9 - 1 to 9 - 7 and a light detector 13 whose field of view is restricted on one side by a shielding plate 14 blocking direct light transmission from light source 12, and on the other side by a labyrinth member 9 - 1 which is longer than the others and is opposite the source 12. The adjacent labyrinth member 9 - 2 may have an inner bent portion 92 to define a parallel passage 95 for emitted light which is then trapped by a further bent portion 94. <IMAGE> |
