The Court of Appeals for the Federal Circuit has reiterated that a patent can only be found invalid for obviousness based on prior art that is analogous to the invention. In Circuit Check Inc. v. QXQ Inc. (available here), the Court reversed a District Court decision throwing out a jury verdict that the defendant infringed the plaintiff's patent on a component of a machine used to test circuit boards.
The District Court found that concepts like rock carving known to "any layman" would render the patent obvious.
The Federal Circuit disagreed because the District Court ignored the rule that invalidating prior art must be in an area "analogous to the invention." Something is not analogous just because it is known to a layperson or one of ordinary skill if the art is not "reasonably pertinent to the particular problem the inventor is trying to solve." The Federal Circuit found that an inventor would not have looked to rock carving in developing a circuit board testing invention. The prior art was not in the same field of invention.