André Charlin

André Marie Bernard Charlin (20 March 1903 – 28 November 1983) was a French audio engineer and entrepreneur. He was a prolific inventor and filed many patents for radio amplifiers, movie sound recording equipment, and music recording. He founded and operated companies to make his equipment and to make the recordings. André Marie Bernard Charlin was born on 20 March 1903 in Paris. He was the second of four children of Georges Charlin (1869–1915) and Louise Rogonot (1879–1930). At the age of 13 he was a talented flutist. His father died that year and his uncle Edmond Ragonot, an electrical engineer, took an interest in the boy and helped him build his first radio receiver. Towards the end of World War I (1914–18) he built an amplifier, and in 1922 he filed his first patent for an electro-dynamic speaker diaphragm embedded in a screen. He sold the rights to this invention to the Compagnie Francaise Thomson-Houston in 1927. He completed his military service in 1926. That year he was granted patents for a push-pull electrostatic loudspeaker and for a variable reluctance pick-up system. He started a small business making radios and loudspeakers. Charlin married Madeleine Blanchard (1907–2006) on 7 October 1926. In the years that followed Charlin was granted many patents for improvements to amplifiers. Charlin became involved in cinematography at a time when sound was starting to be added to motion pictures, and began to build equipment for synchronous sound playback. At first this used 33 rpm records. The first "talkies" appeared in 1931, and Charlin began working on ways to improve sound quality through better recording technology. He founded a recording studio in 1933 that produced the sound tracks for many prewar movies, including in 1934 a stereo sound track for Abel Gance's 1927 silent movie Napoléon. He moved into techniques for film projection with a 1935 patent for "Cyclope" focussing and a 1938 patent for "Actua Colour" to project colour films which was used in over 1,000 movie theatres by 1948.