| 摘要 |
An edge portion includes a center portion, one end and an other end. As seen in a cross section of a vibration plate in the radial direction, the center portion, the one end and the other end each are formed in a circular arc such that the edge portion forms a convex so as to protrude in a direction in which the protruding shape protrudes. The radius of curvature of the circular arc of the center portion is not less than the radius of curvature of the circular arc of each of the one end and the other end. Accordingly, a vibration plate allowing a decrease in the lowest resonance frequency while suppressing the edge portion from being brought into a tensioned state, a speaker unit provided with the vibration plate and a portable information terminal can be provided. |
