In Microsoft v. i4i, the U.S. Supreme Court today unanimously (8-0) affirmed the clear and convincing evidence standard for invalidating issued U.S. patents under Section 282 of the Patent Act (1952).  In 2007, i4i sued Microsoft in U.S. District Court for infringement of i4i’s patent. As part of its defense, Microsoft asked for a jury instruction reciting a preponderance of the evidence standard for finding i4i’s patent invalid, rather than the long-standing clear and convincing evidence standard.  The District Court rejected Microsoft’s lower standard of proof, and a jury found that the patent was valid and that Microsoft infringed, awarding i4i a 9 figure damages sum.  Microsoft appealed to Federal Circuit, asserting in particular, that the District Court improperly instructed the jury on the standard of proof for invalidity.  The Federal Circuit affirmed the lower court’s holding and Microsoft petitioned the Supreme Court for certiorari, which was granted.

In its argument to the Supreme Court, Microsoft argued that either (1) a defendant in a patent infringement action need only convince the jury that an issued patent is invalid by a preponderance of the evidence standard, or (2) alternatively, that at the very least, the preponderance of the evidence standard should apply to evidence that was never considered by the PTO during examination.  The Supreme Court in its decision rejected both of Microsoft’s arguments.

In its decision, the Court first focused on the language of Section 282, which specifies that “[a] patent shall be presumed valid” and “[t]he burden of establishing invalidity of a patent … shall rest on the party asserting such invalidity.”  Microsoft had argued that Federal Circuit precedent establishing a clear and convincing evidence standard was not supported by the 1952 Act because Section 282 did not explicitly set forth that standard.  The Supreme Court noted that, while the statute includes no express articulation of the standard of proof, the statute does use the term “presumed valid,” which has a settled meaning in the common law.  Relying on its long-standing decision in Radio Corporation of America (RCA) v. Radio Eng’g Labs., Inc., 293 U.S. 1 (1934), the Court found that the common law jurisprudence dating back to the 19^th century reflects that Microsoft’s proposed preponderance standard of proof “was too ‘dubious’ a basis to deem a patent invalid.”  According to the common law, the Court held, “a defendant raising an invalidity defense bore a ‘heavy burden of persuasion,’ requiring proof of the defense by clear and convincing evidence.”

The Court also noted that the Federal Circuit has interpreted Section 282 to require this clear and convincing evidence standard for nearly 30 years. And while Congress has amended the patent laws several times since the Patent Act was passed, “the evidentiary standard in § 282 has gone untouched.”  The Court concluded that Congress is well aware of the Federal Circuit’s treatment of the statute, but thus far has not amended the statute, and further that “[a]ny re-calibration of the standard of proof remains in [Congress’s] hands.”

The practical implications of the decisions are many.  First and foremost, the decision preserves the status quo, which in turn maintains the strength of U.S. patents and current patent enforcement mechanisms, particularly as they relate to innovation, business certainty, and job creation.  The Court has also sent a clear signal that, in view of well-established jurisprudence, if the standard is to change, it must be done by Congress, as any such change would have a profound ripple effect on the entire patent system.