Patent ID: 7932900

Claim:
A touch panel device comprising: a rectangular substrate; an excitation element for exciting surface acoustic waves, said excitation element being disposed at a first corner of said substrate; and a receiving element for receiving surface acoustic waves excited by said excitation element, said receiving element being disposed at a second corner of said substrate, said second corner being opposite to said first corner in a diagonal direction of said substrate, wherein surface acoustic waves are propagated between said excitation element and said receiving element in diagonal directions on said substrate, and a position of an object in contact with said substrate is detected based on received results at said receiving element, wherein said excitation element and said receiving element have comb-like electrode fingers, and the number of pairs of said comb-like electrode fingers of said excitation element and/or said receiving element is set according to lengths of propagation distances of the surface acoustic waves, and wherein each of said excitation elements and said receiving elements comprises a film-like piezoelectric body, a comb-like electrode formed over one surface of said piezoelectric body, and a plate electrode formed over the other surface of said piezoelectric body.