Patent ID: 7374354

Claim:
An armature comprising: a flat plate shaped arm that holds an end section of a printing wire at an end of a first side of the arm such that the arm extends in a direction orthogonal to a thickness direction of the printing wire; and a magnetic circuit forming member, for forming a magnetic circuit, which holds a second side of the arm that is opposite to the first side, and which comprises a projecting section that protects from the arm toward a direction in which the printing wire extends; wherein the arm includes a first end face at a same side of the arm as the projecting section, and the first end face comprises: a first orthogonal surface that extends from the first side of the arm toward the magnetic circuit forming member and is orthogonal to the printing wire; a first inclined surface that communicates with the first orthogonal surface and gradually inclines toward the projecting section in the direction in which the printing wire extends; and a concave shaped first curved surface that communicates with the first inclined surface and bends inward with a predetermined curvature to reach the projecting section; and wherein the arm includes a second end face that is positioned opposite to the first end face, and the second end face comprises: a second orthogonal surface that extends from the first side of the arm toward the magnetic circuit forming member and is orthogonal to the printing wire; and a convex shaped second curved surface, which is opposite to the first curved surface and communicates with the second orthogonal surface, and which curves outward with a predetermined curvature.