Patent ID: 7948627
Filing Date: 2011-05-24
Classification: G01N,G08B

Abstract:
1. A photoelectric smoke detector for detecting presence of smoke by utilizing a light emitting element and a light receiving element whose optical axes intersect with each other, the photoelectric smoke detector comprising: a casing for storing the light emitting element and the light receiving element; inlet and outlet ports respectively provided in one and another sides of the casing, the inlet and outlet ports bringing air flow into the casing; respective rectifying light blocking means provided contiguously with each of the inlet and outlet ports, the rectifying light blocking means preventing entry of disturbance light into an interior space and forming a flow line of smoke extending from one of the inlet and outlet ports to the other of the inlet and outlet ports, the flow line passing through a detection area by the light emitting element and the light receiving element; and respective air chambers disposed between the inlet and outlet ports and the respective rectifying light blocking means, the air chambers temporarily reserving air taken in through the inlet and outlet ports and then delivering the air to the rectifying light blocking means.