Patent ID: 10943453

Abstract:
A light shielding section for inhibiting ambient light from entering a detection space 34 for detecting smoke contained in a gas is included, the light shielding section includes an inner labyrinth 36 that covers an outer edge of the detection space 34 and has a first inner inflow opening 36f, a detector body 4 disposed at a position facing the first inner inflow opening 36f, the position being separated from the first inner inflow opening 36f by a first gap 38, and an outer labyrinth 37 disposed at a position separated from the first gap 38 by a second gap 39 on an imaginary line orthogonal to a direction in which the first inner inflow opening 36f and the detector body 4 face each other, the imaginary line passing through the first gap 38, and the gas outside the light shielding section is allowed to flow into the detection space 34 through the second gap 39, the first gap 38, and the first inner inflow opening 36f in order.