 In the USA, RCA engineer Randall C. Ballard patented the same idea in 1932.Commercial implementation began in 1934 as cathode ray tube screens became brighter, increasing the level of flicker caused by progressive (sequential) scanning.In 1936, when the UK was setting analog standards, early thermionic valve based CRT drive electronics could only scan at around 200 lines in 1/50 of a second (i.e.