I recently answered this question on a LinkedIn forum as follows:
Innovation = invention + commercialization
Neither of these steps is as easy as this formula would suggest.
An invention must be (like patents) new/novel/non-obvious including an improvement as well as useful (value creation).
Commercialization involves manufacturing/producing and delivering the invention to end-users and having them use it and benefit from it (value capture) whether for profit or not.
The first (circular) slide rule was invented in 1622 by William Oughtred (18 years after John Napier described the logarithm upon which it is based). It is unclear if he also was the one who commercialized ("innovated"?) it. Source: Wikipedia
This is my favourite slide rule, that I bought and enjoyed using in high school math and science.