Nittan Company Limited

Yasunori Oya

Ichiro Hamada

Kazuyoshi Sakurai

Takeshi Ueno

Ryoichi Yamasaki

A dark chamber is adapted to accommodate smoke particles. A photo emitter and a photo detector are disposed in the dark chamber. In a first region, a region where light emitted from the photo emitter passes and a region where the photo detector is capable of detecting light are overlapped, so that light emitted from the photo emitter and scattered by the smoke particles is detected by the photo detector. A photo converger converges light passed through the first region at a second region where is an outside of the first region.

Smoke detector

Fire detector

A fire detector which can be observed an operating state thereof from every direction and decrease a cost thereof as possible. The fire detector (,) comprises: the circuit board (,) in which the circuit for detecting a fire is formed; the LED (,) which is surface-mounted on the circuit board (,); and the indication lamp for indicating the fire detector being under detection by emitting the light emitted from the LED (,), wherein the indication lamp comprises the light guide member (,) for introducing the light emitted from the LED (,) to the indication lamp with a ring shape, the light guide member (,) comprises the light incident parts (,) and (,) and the ring member (,), notches (,) and (,) are formed in the vicinity of the light incident parts (,) and (,) of the ring member (,), and a plurality of small grooves (,), and (,) . . . are formed in the bottom surface (,) of the ring member (,).

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Shibuya-ku, Japan

Yasunori Oya