| 摘要 |
PURPOSE:To provide an acceleration sensor in which the size can be reduced by simplifying the structure. CONSTITUTION:The first silicon substrate 2 of a three-dimensional acceleration sensor is provided with a light introduction hole 5. The light introduction hole 5 is made into a rectangular horn-shape opening toward the surface 2b of the substrate 2. Phototranbistors 6a-6d, 7a-7d are disposed along the upper fringe of the light introduction hole 5 on the surface 2b of the substrate 2. A second silicon substrate 3 is provided with beams 9a-9d for supporting a mass part 10. The mass part 10 is formed into a pyramid having four side faces which define optical paths 11a, 11b, etc., along with the inner wall faces 5a-5d of the light introduction hole 5. A light is introduced from the hole 5 through the optical paths 11a, 11b, etc., to the phototransistors 6a-6d, 7a-7d. The quantity of light passing through the optical paths 11a, 11b, etc., depends on the mass part 10 moving at an applied acceleration. |
