Surviving An Obviousness Patent Challenge

To be patentable, an invention must not have been obvious at the time the invention was made. But how do courts actually determine this?

The fundamental difficulty is that courts are being asked to make a hypothetical judgment—whether or not an invention would have been obvious—long after the fact. The patent law is clear that the judgment should be made based only on what was known at the time the invention was made, and that the way in which the inventor developed the invention—whether by flash of genius or trial and error—should not be relevant. Unfortunately, even though legally it should not, hindsight and the inventor's own work can color this determination, since inventions often seem obvious after the fact.