The development of electronic television systems was based on the development of the cathode ray tube (CRT). A cathode ray tube aka picture tube, was found in all electronic television sets up until the invention of the less bulky LCD screens. The first cathode ray tube scanning device was invented by the German scientist Karl Ferdinand Braun in 1897. However it was not until 1931 that a commercially practical and durable CRT for television was invented by Allen B. Du Mont.