The Supreme Court’s decision in Nautilus1 is considered by many as a significant development for accused infringers asserting indefiniteness. The decision is viewed as relaxing the standard thereby making it easier for accused infringers to prevail on indefiniteness. In place of the previously applied and relatively strict “insolubly ambiguous” standard, the Supreme Court adopted a new standard requiring that “a patent’s claims, viewed in light of the specification and prosecution history, inform those skilled in the art about the scope of the invention with reasonable certainty.”2 In Interval Licensing,3 the Federal Circuit applied the new indefiniteness standard for the first time and indicated a rebalancing of the indefiniteness standard in favor of accused infringers.

Indefiniteness Pre- and Post-Nautilus

Applicants for patents are required by statute to “particularly point out and distinctly claim the subject matter which [the applicant] regards as the invention.”4 Whether a claim meets this requirement is evaluated through the eyes of a person of ordinary skill in the art at the time of the application and in light of the specification and prosecution history.5

Before Nautilus, a claim would be upheld as definite if it was “amenable to construction” and was not “insolubly ambiguous.”6 Under this patentee-friendly approach, the Federal Circuit would find claims to be sufficiently definite if at least some construction could be applied to the limitation in question. In other words, indefiniteness required a finding that construction of a claim limitation was essentially impossible.7

In Nautilus, however, the Supreme Court noted that the Federal Circuit standard bred confusion in the lower court and lacked the precision necessary to provide adequate certainty as to claim scope.8 The Supreme Court noted that “[t]o tolerate imprecision just short of that rendering a claim ‘insolubly ambiguous’ would diminish the definiteness requirement’s public-notice function and foster the innovation-discouraging ‘zone of uncertainty,’ against which this Court has warned.”9 Accordingly, the Supreme Court rejected the old indefiniteness standard, emphasizing that the proper test is whether “a patent’s claims, viewed in light of the specification and prosecution history, inform those skilled in the art about the scope of the invention with reasonable certainty.”10

Background of Interval

The patents at issue in Interval were directed to an “attention manager for occupying the peripheral attention of a person in the vicinity of a display device.”11 To ensure that the attention manager was attracting only the “peripheral attention” of a user, the attention manager made use of “used capacity” of the display device, i.e., display capacity that was not already dedicated to the user’s primary interaction with the display device.12 Interval sued AOL, Apple, Google, and Yahoo! for patent infringement based on the use of “pop-up” notifications in various products and software.13

The patent specification described two embodiments of the attention manager that took advantage of two different types of “unused capacity.” In the first “screen saver” embodiment, the attention manager made use of unused “temporal” capacity by displaying images on the display when the display was left idle.14 In the second “wallpaper” embodiment, the attention manager took advantage of “spatial” capacity by displaying images in areas not being used by the user’s primary interaction.15

The main issue on appeal centered on claim language related to “how the attention manager displays ‘images’ so as to attract the peripheral attention of the user.”16 The claims required that the images be displayed “in an unobtrusive manner that does not distract a user.”17 The lower court held that the terms “in an unobtrusive manner” and “does not distract” were both indefinite because the patents “fail[ed] to provide an objective standard by which to define the scope of [‘in an unobtrusive manner’]” and because whether an accused product met the claim limitations (i.e., did not distract the user) was highly dependent on the circumstances under which the accused product was used.18

Indefiniteness in Interval

The Federal Circuit found the term “in an unobtrusive manner that does not distract a user” to be “highly subjective” because “whether something distracts a user from his primary interaction depends on the preferences of the particular user and the circumstances under which any single user interacts with the display.”19 Although such subjective terms may facially lack “reasonable certainty” regarding their scope, they are not inherently indefinite provided the specification and prosecution history contain a suitable objective standard for measuring the subjective aspects of the term.20 Accordingly, the court in Intervalturned to the specification and prosecution history to determine if either contained a standard for performing a task “in an unobtrusive manner.”

Based on passages from the specification and prosecution history, Interval argued that the phrase “unobtrusive manner” was strictly limited to the “wallpaper” embodiment, and as a result, was sufficiently definite as it related only to spatial obtrusiveness.21 The court disagreed. While the specification and prosecution history lacked clear and direct statements regarding obtrusiveness as related to the “screensaver” embodiment, the court found that “the specification [was] at best muddled, leaving one unsure of whether the ‘unobtrusive manner’ phrase has temporal dimensions as well as spatial dimensions.”22

Alternatively, Interval tried to hang its hat on a sentence in the Summary of the Invention which provided that information can be presented “in an unobtrusive manner that does not distract the user from the primary interaction with the apparatus (e.g., the information is presented in areas of a display screen that are not used by displayed information associated with the primary interaction with the apparatus).”23 Although the court recognized that examples in the specification may be used to support a claim term’s definiteness, it declined to do so when faced with “a single ‘e.g.’ phrase from a lengthy written description.”24 Further, the court recognized that even if the example were to be adopted, various ambiguities would still remain.25

The Nautilus Effect

Although the court’s decision relied heavily on pre-Nautilus case law to support the indefiniteness finding, the court’s opinion suggests that the Federal Circuit has rebalanced its approach to indefiniteness in light of Nautilus.

When discussing the “e.g.” argument, the court noted that “[h]ad the [‘e.g.’] phrase been cast as a definition instead of as an example—if the phrase had been preceded by ‘i.e.’ instead of ‘e.g.’—then it would help provide the clarity that the specification lacks.”26 Pre-Nautilus, this part of the opinion may have turned out differently. because under the old indefiniteness standard, a patentee was only required to show that a claim limitation was “amenable to construction” and not “insolubly ambiguous.” So, provided a claim limitation could be construed in at least one way, the claim could be found sufficiently definite (although significantly narrowed).27

The statement following “e.g.” in the specification offers at least one potential construction for “in an unobtrusive manner,” specifically that the “the information is presented in areas of a display screen that are not used by displayed information associated with the primary interaction with the apparatus.”28However, instead of adopting the example as its construction and limiting the claims to the example only, the court opted for a finding of indefiniteness. Explicitly citing Nautilus for the proposition that “‘post hoc’ efforts to ‘ascribe some meaning to a patent’s claims’” are disfavored, the court noted that “[w]ith this lone example, a skilled artisan is still left to wonder what other forms of display are unobtrusive and non-distracting.”29 So, despite the claim limitation being amenable to at least one construction—which may have been sufficient to support a finding of definiteness pre-Nautilus—the court found the claim to be indefinite.

It is still too early to develop a full picture of the Nautilus decision and its effects, but the Federal Circuit’s decision in Interval is consistent with the Supreme Court’s goal of rebalancing the indefiniteness standard. As more appeals on the issue arise, the Federal Circuit will likely provide additional clarity regarding what is required for claim language to be “reasonably certain.” Currently, however, it appears that Nautilus has significantly strengthened the ability of accused infringers to challenge definiteness.