Friday, February 9, 2007

Pixar's Monte Carlo Patent done?

Pixar patented Monte Carlo for graphics back in the mind-1980s, and for reasons I don't know the patent wasn't issued (#4897806) until Jan 1990. That is in the transitional phase of patent law as I understand it, so it expired 17 years after being issued-- i.e., last month. So is Monte Carlo now fair game in the US? I would think so, but there are also patents 5025400 and 5239624 that last until 2009 and 2011 respectively. They seem to my eye to not really claim anything new that was not in the original patent or the fabulous 1984 SIGGRAPH paper. Anyone have any more informed wisdom on this?

1 comment:

Unknown said...

My understanding is the same as yours. In 1990, utility patents were granted for 15 years from the date of issue with an optional 2 year extension (which I assume Pixar requested). That means the first patent expired in January 2007. What haven't expired yet are any new claims made in 5239624 and 5025400 which were not present in the original. It's going to take some effort to compare the legalese of the claims to determine what, if any, was added.

There's another patent (6300956) filed in 1998 that covers the application of stochastic sampling to level of detail. Ironically, one of the inventors was on the wrong end of a patent infringement lawsuit with Pixar.