An inventor cannot obtain a patent “if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains.” 35 U.S.C. § 103(a). In other words, if your invention is obvious, you can’t patent it.
To determine whether an invention was obvious, the Federal Circuit had employed the “teaching, suggestion or motivation” test (“TSM”), “under which a patent claim is only proved obvious if ‘some motivation or suggestion to combine the prior art teachings’ can be found in the prior art, the nature of the problem, or the knowledge of a person having ordinary skill in the art.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 407 (2007).
In KSR, the Supreme Court held that the Federal Circuit’s “rigid” TSM test was not required to be satisfied in order to prove that a patent was obvious. 550 U.S. at 415 (“We begin by rejecting the rigid approach of the Court of Appeals.”). The Supreme Court also noted that “[t]he combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results” id. at 416; “[t]he question is not whether the combination was obvious to the patentee but whether the combination was obvious to a person with ordinary skill in the art” id. at 420; and “the fact that a combination was obvious to try might show that it was obvious under § 103” id. at 421.
Post-KSR, then, it has become easier to prove that a patent is invalid because it is obvious.