Vladimir Kosma Zworykin (1889-1982), a Westinghouse Electric and Manufacturing Company research engineer, is shown in 1934 demonstrating his new cathode ray television set, "which can entertain large groups instead of one or two spectators." Mildred Birt looks on with interest. The broadcast images are projected on a mirror on the top of the cabinet making it possible for many to watch. The first cathode ray tube to use a hot cathode was developed by John B. Johnson (who gave his name to the term Johnson noise) and Harry Weiner Weinhart of Western Electric, and became a commercial product in 1922. It was named by inventor Vladimir K. Zworykin in 1929. RCA was granted a trademark for the term (for its cathode ray tube) in 1932; it voluntarily released the term to the public domain in 1950. The first commercially made electronic television sets with cathode ray tubes were manufactured by Telefunken in Germany in 1934.