| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance an accuracy for identifying smoke and surely prevent an erroneous fire alarm. <P>SOLUTION: A smoke detector is provided with: a first light emission element 9 for emitting a first wavelength λ1 to a smoke detection space; a second light emission element 10 for emitting a second wavelength λ2 different from the first wavelength λ1; and a light reception element 11 disposed at a location for indirectly receiving lights emitted from the first and second light emission elements 9, 10. A second scattering angle θ2 formed by an intersection of optical axes 10a, 11a of the second light emission element 10 and the light reception element 11 is larger than a first scattering angle θ1 formed by an intersection of optical axes 9a, 11a of the first light emission element 9 and the light reception element 11. The second wavelength λ2 emitted from the second light emission element 10 is shorter than the first wavelength λ1 emitted from the first light emission element 9. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
