From 1929 onwards, the BBC made broadcasts using the Baird television system, alternating these with broadcasts of electronic scanning system television signals during the 1930s, until it finally discontinued broadcasts of the Baird system in 1937.
Baird's mechanical television system was replaced by the electronic television system described by A.A. Campbell-Swinton and later developed by inventors such as Philo T. Farnsworth and Vladimir Zworykin.
Baird never stopped inventing. His 1928 invention called the Phonodisc was basically a 78rpm record that could play a 30 line video signal. Shortly before his death he demonstrated his own colour television system, which had 1000 lines of definition and good picture quality. It was not compatible with exsisting black and white television so was never adopted.