Whiteboard
Whiteboards became commercially available in the early 1960s, but did not become widely used until 30 years later. Early whiteboards needed to be wiped with a damp cloth and markers had a tendency to leave marks behind, even after erasing the board. Dry-erase markers for whiteboards were invented in 1975.
Aiken tube
The Aiken tube was the first successful flat panel black and white television. Originally designed in the early 1950s, a small number of tubes were built in 1958 for military use in a collaboration with Kaiser Industries. An extended patent battle followed with a similar technology developed in the United Kingdom and planned commercial production for the home market never started. Further development was carried out by a number of companies, including Sinclair Electronics and RCA after the patents had expired.