The district court granted summary judgment of invalidity based on the conclusion that the term “visually negligible” was indefinite under 35 U.S.C. 112. The district court explained that the claim language provided no guidance on that “purely subjective” term, and that the written description failed to provide a person of ordinary skill in the art (POSITA) with a reasonably certain meaning with a defined scope or any other objectively measurable standard.

On appeal, the Federal Circuit reversed and held that a POSITA would have understood, with reasonable certainty, what the term “visually negligible” meant. The specification provided an objective baseline for the interpretation of “visually negligible”—what can be seen by the normal human eye. Although explicitly declining to offer bright-line rules concerning sufficient disclosure to avoid indefiniteness, the Federal Circuit highlighted several factors persuasive in finding that the term was not indefinite to a POSITA. In particular, the specification provided a general exemplary design for a visually-negligible indicator, gave two specific examples of such indicators, and described the requirements for the indicators as “being negligible to human eyes.” Moreover, the prosecution history included multiple reexaminations, during which neither the parties involved nor the United States Patent and Trademark Office had any apparent difficulty in understanding or applying the term.