ABSTRACT OF THE DISCLOSUREA light-scattering-type smoke detector having aprojecting element and a light receiving element surrounded by alabyrinth is disclosed wherein the labyrinth comprises an arrayof a plurality of light shielding columns arranged in a circleeach having a substantially J-shaped cross section, and the headportion of each column is inclined relative to the bisector of anangle formed between the lines connecting a first reflectingpoint with the projecting and light receiving elements, the lightshielding columns having darkly colored light reflectivesurfaces.
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