Patrick tamer bowie invented led signs in 1979
The addition sign was invented in Oakland California.
An LED sign is an output device.
The plus or addition sign was invented by Michael Stiple in 1544
The person who invented the plus sign is the same as the minus
E-mail and @ sign were invented by Ray Tomlinson. by aliou waiga.
"Nick Holonyak, 75, invented the LED (light emitting diode) in the 1960s."
I don't know about LED TV but i know LED (Light Emitting Diodes) was invented in 1962 so most likely not too long after that.
William Oughtred invented it in 1631.
It is invented by Michael Stiple in 1544
It was invented in 1620
Russia 1920
1974