| 摘要 |
PURPOSE:To constitute a thin smoke detector of single-layer structure by fitting a light emitting element and a photodetecting element directly to a printed board on the same plane together with an electronic part. CONSTITUTION:An intake 10 for smoke is formed in an outer circumferential surface. Chip type electronic parts 3 and fitted onto the top surface of the printed board 2 and large-sized nonchip-type electronic parts 3, light emitting element 4, and photodetecting element 5 are fitted to the reverse surface. Smoke entering the device body 1 from the intake 10 passes through the slit of a cylindrical light shielding plate 9 to reach an arrangement chamber for optical parts for smoke detection. Thus, the light emitting element and photodetecting element are fitted directly to the printed board without using any holder because of the single-layer structure, so that the overall height is reduced by half. |
