The economic slump has yet to damp innovation in Silicon Valley, at least not by one widely followed measure: patent production.

Silicon Valley denizens received 13,231, or 7.9%, of the total 167,350 "utility" patents granted in the U.S. in 2009, according to IFI Patent Intelligence, a unit of Wolters Kluwer Health that analyzes patent data from the U.S. Patent and Trademark Office. That is on par with Silicon Valley's share of patents nationwide in 2008 and 2007, according to IFI.

Utility...