10 inventors who didn't get mega-rich from their inventions

Doug Engelbart, who has died aged 88, never really made any money from inventing the mouse. Here are 10 others who didn't get to be billionaires.

1. LEDs

When Nick Holonyak Jr invented the first practically useful LED in 1962 he predicted it would one day replace Edison's lightbulb. Holonyak's colleagues have said he should be given the Nobel Prize but he humbly says: "It's ridiculous to think that somebody owes you something. We're lucky to be alive, when it comes down to it."

2. Post-It Notes

3M sell billions of Post-It Notes each year but its inventors describe themselves as "comfortably off" not wealthy. They were the co-creation of Dr Spencer Silver, who in 1968 developed an adhesive that had a "removability characteristic", and his colleague Art Fry hit on the idea of a bookmark that would stay in place in his hymnbook.

3. AK-47

The Kalashnikov rifle, or AK-47, was invented by Soviet Army soldier Mikhail Kalashnikov while recovering in hospital from injuries sustained in World War II. Kalashnikov claimed his creation was for the benefit of his country.

BBC News - 10 inventors who didn't get mega-rich from their inventions