The Software IP Report

“Virtually Free From Interference” Not Indefinite Claim Term

By Mike McCandlish

Categories: 35 U.S.C. § 112, The Software IP Report

In a precedential and split decision, the Federal Circuit reversed the International Trade Commission and found patent claims reciting the term “virtually free from interference” not indefinite. One-E-Way, Inc., v. International  Trade Commission, No. 2016-2105, (Fed. Cir. June 12, 2017) (Opinion by Judge Stoll, joined by Judge Wallach, Dissenting Opinion by Chief Judge Prost).  Applying the standard established by the U.S. Supreme Court in Nautilus v. Biosign Instruments, Inc., the majority determined that the specification and prosecution history would inform a person of ordinary skill in the art about the scope of the invention with reasonable certainty.

One-E-Way filed a complaint with the International Trade Commission (ITC) accusing SONY Corporation, and multiple other defendants of infringing U.S. 7,865,258 and U.S. 8,131,391.The ‘258 and ‘391 patents share a common specification and disclose a wireless digital audio system to let people use wireless headphones privately, without interference, even when multiple people are using wireless headphones in the same space. (Abstract.)

Multiple claims from the ‘258 and ‘391 patent included the claim term “virtually free from interference.” As an example, claim 8 from the ‘258 patent recites in part:

a module adapted to reproduce said generated audio output, said audio having been wirelessly transmitted from said audio source virtually free from interference from device transmitted signals operating in the portable wireless digital audio system spectrum.

The ITC initially determined “virtually free from interference” to be indefinite because one of ordinary skill in the art had “no guidepost in the intrinsic or extrinsic evidence from which [she] could discern the scope of the limitation.”

The Federal Circuit disagreed, and found that the intrinsic evidence supported One-E-Way’s construction of this term to mean “free from interference such that eavesdropping on device transmitted signals operating in the . . . wireless digital audio system spectrum cannot occur.”

The majority first pointed to language in the specification stating that private listening is “without interference” from other user’s wireless audio transmission devices. Based on this language, the majority concluded that “the specification makes it clear that private listening is listening without interference from other users.”

The majority then turned to the prosecution history, and cited the following excerpt:

As is agreed to by the Applicant and the Examiner, most recently discussed during the teleconference with the Examiner on June 3, 2009, Lavelle [prior art] does not teach, disclose, or suggest such a relationship where interference is virtually eliminated (e.g. where eavesdropping cannot occur) where multiple receivers and transmitters occupy the same environment.

This language, says the majority, suggests that virtually eliminating interference results in listening without eavesdropping. Although “virtually” is a term of degree, a person of ordinary skill in the art would be informed that “virtually free from interference” means that the claimed invention does not allow for eavesdropping.

The dissent, agreeing with the Commission, took the position that the term “virtually free from interference” does not appear in the specification. The one example for determining when audio is “virtually free from interference”, appearing in the prosecution history, is simply not enough to inform a person of ordinary skill in the art about the scope of the invention with reasonable certainty.

Lessons for Practice

In some cases, as noted in Nautilus, “absolute precision is unattainable.” It is reassuring that applying the Nautilus standard results in permitting “some modicum of uncertainty,” as intended. A technical specification limiting a term is not always available. In those cases, providing a practical standard (listening such that eavesdropping cannot occur), may be enough to inform one skilled in the art about the scope of your invention. Nonetheless, One-E-Way could have avoided a lot of trouble by defining the term in the specification.