亞歷山大‧葛拉罕‧比爾 (Alexander Graham Bill) 在1880年6月3日發明了光影電話 (photophone)

Alexander Graham Bell's design sketch of the telephone, ca. 1876.

亞歷山大‧葛拉罕‧貝爾的電話設計草圖

出處: Bell, Alexander Graham. "Alexander Graham Bell's design sketch of the telephone, ca. 1876. " Ca 1876. Alexander Graham Bell Family Papers, Manuscript Division, Library of Congress.