Hearing Components, Inc. v. Shure, Inc., Appeal No. 09-1364 (Fed. Cir. 2010)

This case has three interesting issues: (1) the definiteness of "terms of degree" claim elements; (2) interpreting means-plus-function claim limitations; and (3) the standard for appellate review of a jury's non-obviousness determination. In this decision, the resolution of each of these issues favors the patentee, Hearing Components.

Terms of Degree: The patents-in-suit all relate to hearing-aide elements. Claim 1 included a long-preamble with the statement that the device is configured to be "readily installed and replaced by a user." The district court had difficultly drawing a boundary between devices that are readily installed and those that are not readily installed and therefore found the claim indefinite and invalid. On appeal, the Federal Circuit reversed.

In Datamize, the Federal Circuit held the claim term "aesthetically pleasing" to be indefinite. In the process, however, the court noted that these seemingly loose terms of degree will not be considered indefinite if the patentee "provides some standard for measuring that degree." In the present case, the court found several hints as to the standard for "readily installed." First, the patentee had argued that the readily limitation helped the claim avoid prior art – thus defining a category of items that were not readily installed. Second, the patent application discussed user installation "without tools." The Federal Circuit held that this discussion suggested another way to measure "readily." Based on these findings, the appellate panel rejected the indefiniteness holding because – in the words of Datamize – the specification "supplies some standard for measuring the scope of the phrase."

Means-Plus-Function Claims: The patent claimed a "means … for disposably attaching" a duct of the hearing aide to a connector. The specification included several examples, but did not include the specific arrangement of the accused device. The jury found infringement, but the district court flipped that decision in a post-verdict order. On appeal, the Federal Circuit confirmed and reinstated the jury verdict of infringement.

Means-plus-function claims often appear to be broadly written, but are limited to specific structures described in the specification and equivalents to those structures. Thus, a means-plus-function element is infringed if the accused device includes a relevant structure that performs the same function as described in a way that is at least equivalent to one described in the specification.

Here, Federal Circuit held that the jury had permissibly found that the accused product's "interference fit" was equivalent to the "screw threads or ball-and-socket attachment" disclosed in the application.

There was evidence that the inventors knew of the potential of using an interference fit attachment but chose not to disclose it in the specification. The defendant argued that evidence of prior knowledge should limit the scope of equivalents under a doctrine akin to estoppel. Instead, the Federal Circuit held that the "known interchangeability" weighs in favor of a finding of equivalence.

Reviewing a Non-Obviousness Determination: In John Deere, the Supreme Court divided the issue of obviousness into a series of factual inquiries leading to an ultimate conclusion of whether a patent is obvious. The ultimate question of obviousness is an issue of law reviewed de novo on appeal. However, a jury's findings regarding the question's many underlying factual predicates are reviewed for substantial evidence. This structure is normally ignored in a jury decision because the jury is typically not asked to explain its factual predicates. Rather most juries just answer the yes/no question: "Is the claim obvious?" When unpacking the decision on appeal, the Federal Circuit gives the jury the benefit-of-the-doubt by looking for any way that the evidence presented can support the jury's conclusion. Thus, the question on appeal boils down to whether the factual evidence presented could be sufficient to support the legal conclusion on obviousness.