But, at least in the past, it seemed like there might be some question about exactly who owned some of the key patents on multitouch technology.

"I would therefore personally not call it a 'key' patent."

This ultimately was demonstrated by a multitude of key patents.

That's when a time limit on key patents worked in the favor of backyard grillers.

The decision rests on a key patent filed by Apple in 1996, which is valid until 2016.

Such technology is extremely familiar to all smartphone users today, making this a key patent for for the industry.

Microsoft hit back saying Google had been invited to bid with it on key patents but turned down the chance.

It happened so that three different companies held the key patents to each of these problems.

There was a key patent which covered the early Strida 1 onwards.

But a key patent for terazosin was due to expire that year, and generics were already lining up to compete.