| 摘要 |
PROBLEM TO BE SOLVED: To provide a photoelectric smoke sensor having good characteristics of smoke inflow to a smoke detector even if the sensor is formed smaller in thickness and size.SOLUTION: The smoke detector 1 of a fire alarm 100 has: a plurality of wall members 12 for preventing external light from entering the smoke detector 1; a light-emitting element 22 for emitting light to the inside of the smoke detector 1; and a light-receiving element 23 for receiving the light of the light-emitting element 22, which is scattered by smoke particles flowing into the smoke detector 1. Each of the wall members 12 is formed roughly in a Y-shape, and the plurality of wall members 12 are approximately equally spaced between adjacent wall members 12. |
