Patent ID: 7574914

Claim:
An acceleration sensor comprising a base; a frame-shaped beam portion disposed above a surface of the base in a floating state; a beam-portion supporting/fixing unit including support portions and being arranged to connect the beam portion to the base so as to be supported on two sides via the support portions, the support portions extending outward in an X-axis direction from either side of the beam portion, the X axis, a Y axis, and a Z axis being substantially perpendicular to one another; connecting portions provided above the surface of the base in a floating state and extending outward in the Y-axis direction from either side of the beam portion in the Y-axis direction; and weight portions connected to distal ends of the respective connecting portions; wherein the weight portions are movable in three axial directions including the X-axis direction, the Y-axis direction, and the Z-axis direction when the frame-shaped beam portion is deformed; the beam portion is provided with an X-axis-direction acceleration detection unit arranged to detect an acceleration in the X-axis direction based on deflection of the beam portion caused by the movements of the weight portions in the X-axis direction, a Y-axis-direction acceleration detection unit arranged to detect an acceleration in the Y-axis direction based on deflection of the beam portion caused by the movements of the weight portions in the Y-axis direction, and a Z-axis-direction acceleration detection unit arranged to detect an acceleration in the Z-axis direction based on deflection of the beam portion caused by the movements of the weight portions in the Z-axis direction; and the Z-axis-direction acceleration detection unit is provided near proximal ends of Y-axis-direction extending portions of the frame-shaped beam portion and the Y-axis-direction acceleration detection unit is provided near distal ends of the Y-axis-direction extending portions, the Y-axis-direction extending portions extending in the Y-axis direction from locations at which the frame-shaped beam portion is supported by the support portions.