On December 7, 1880, Alexander Graham Bell patented photophone, which allowed for the transmission of speech on a beam of light.
Bell believed the photophone was his most important invention. He said the photophone was “his greatest invention, greater than the telephone”.
Patent Information
Publication number: US235199 A
Patent Title: Alexander g
Publication type: Grant
Publication date: 7 Dec 1880
Filing date: 28 Aug 1880
Inventors: Alexander G. Bell
