Patent ID: 8826748

Claim:
A stress-detecting element comprising: a support body having an opening part with a first rectilinear section and a second rectilinear section extending parallel to each other; a support film disposed over the support body and blocking off the opening part; a first piezoelectric element disposed over the support film along the first rectilinear section of the opening part of the support body so as to straddle the first rectilinear section from an interior area of the opening part to an exterior area of the opening part as seen in plan view along a film thickness direction of the support film, the first piezoelectric element being configured and arranged to output an electric signal upon deformation; a first elastic part disposed over the support film along the first rectilinear section of the opening part of the support body so as to straddle the first rectilinear section from the interior area of the opening part to the exterior area of the opening part as seen in plan view, the first elastic part having a first elastic end section disposed in the interior area of the opening part as seen in plan view; and a second elastic part disposed over the support film along the second rectilinear section of the opening part of the support body so as to straddle the second rectilinear section from the interior area of the opening part to the exterior area of the opening part as seen in plan view, the second elastic part having a second elastic end section disposed in the interior area of the opening part as seen in plan view, the second elastic end section being spaced apart from the first elastic end section, wherein the first elastic end section of the first elastic part and the second elastic end section of the second elastic part are parallel to the first rectilinear section and the second rectilinear section as seen in plan view, a distance from the first rectilinear section of the opening part to the first elastic end section is equal to a distance from the second rectilinear section to the second elastic end section as seen in plan view, and each of the distance from the first rectilinear section of the opening part to the first elastic end section and the distance from the second rectilinear section to the second elastic end section is 10% to 30% of a distance from the first rectilinear section to the second rectilinear section.