The Software IP Report

Patent Obviousness and Reasonable Expectation of Success

The Federal Circuit has (mostly) sustained the PTAB’s findings that claims of US Patent No. 7,433,483 are obvious over prior art, explaining that obviousness under 35 USC § 103 required, in essence, a showing that the proposed combination of references would result in an improvement, even if not the best possible improvement. Slot Speaker Technologies, Inc. v. Apple Inc., Nos. 2015-2038, 2015-2039 (Fed. Cir. Feb 17, 2017) (non-precedential). Accordingly, the Federal Circuit panel (opinion by Judge O’Malley, joined by Judges Lourie and Dyk) held that claims 1-3 of the ’483 patent would have been obvious, affirming and reversing in part the PTAB’s final decision in an Inter Partes Review proceeding.

Claim 1 of the ’483 patent recites:

A narrow profile sound system, comprising:

a drive unit disposed on a mounting surface, said mounting surface forming a barrier acoustically isolating the drive unit’s forward radiation from its rearward radiation;a sound reflecting surface facing the drive unit and substantially parallel with the mounting surface; and

sound damping material disposed between said sound reflecting surface and the mounting surface, the sound reflecting surface and the mounting surface defining a bottom and top of a narrow sound duct terminating in an elongate output slot, with the sound damping material forming sides of the sound duct, whereby forward radiation from the drive unit is turned at a substantially right angle and channeled along a straight path towards the output slot;

wherein the sound damping material forms an outer shape of the sound duct which reduces sound reflections at the end of the sound duct opposite the output slot and thereby mitigates standing waves.

A primary reference, Tomonori et al., EP 0744880 A1, disclosed everything but “sound damping material forming sides of the sound duct.” For this limitation, the PTAB relied on a secondary reference, Sadaie et al., WO Pub. No. 00/52958. The PTAB found that the sound damping materials of the two references fulfill the same function, and it would have been obvious to extend the sound damping of Tomonori “along the side walls of the duct, as taught by Sadaie,” as “one of a limited number of known solutions further minimizing the presence of various resonances and standing waves inside the duct.”

The Federal Circuit first addressed whether Sadaie “teaches sidewall-only placement of the sound damping material.” The Patent Owner admitted that Sadaie allowed sound damping material to be placed “on any appropriate position on the wall surface according to the purpose,” and thereby implicitly conceded the point. The patent-owner’s argument that “sidewall-only placement is a species within the genus of placement of sound absorbing material” therefore failed; Sadaie distinguished between various wall surfaces, and disclosed particular embodiments in which it allowed “the placement of two different types of sound damping material on its side walls and back wall, not its top wall or bottom wall.”

Further, the references would have been combined. The PTAB had found not simply that one of ordinary skill “would have substituted Sadaie into Tomonori,” but that Sadaie’s teachings would have caused one of ordinary skill to recognize “that the sound damping material along Tomonori’s back wall could be extended along Sadaie’s side walls to suppress unwanted sound waves.” One of ordinary skill would have had a reasonable expectation of success because the proposed combination would have improved absorption in a low frequency range.

And now we come to the particularly instructive part of this case. The court rejected the patent owner’s argument that Sadaie would not have taught improving absorption in all sound ranges. It was irrelevant to a reasonable expectation of success that the references “together would be less effective than Sadaie alone at avoiding the absorption of certain low frequencies.” Similarly to no avail was the patent-owner’s argument that the references were “incompatible because they are directed to different goals.”  That is, Sadaie taught that it sidewalls absorbed pressure in addition to sound waves. It was enough that “a person of ordinary skill in the art would have recognized that Sadaie’s sidewall-only placement of sound damping material suppresses standing waves.”

The court conducted a similar analysis, and reached the same result, on dependent claims 2 and 3, reversing the PTAB’s holding that the latter claim was not obvious.


Obviousness, especially after KSR v. Teleflex, is a slippery thing. This case is a reminder that arguments that a primary reference could not or would not have borne a simple substitution of a secondary reference are unlikely to be persuasive. If the references do not teach away from each other, and a secondary reference suggests a benefit in the context of the primary reference, that may be enough for a rejection, or a finding of invalidity, to be sustained. That said, obviousness is not an open-ended analysis, and this case must be viewed through a prism that includes other recent cases where obviousness findings were not supported by the evidence.