In one of his most famous dialogues from The Tempest, William Shakespeare’s character Prospero draws on the metaphor of the end of a wedding revelry to solemnly comment on the fleeting definiteness of existence.
Our revels now are ended. These our actors,
As I foretold you, were all spirits, and
Are melted into air, into thin air:
And like the baseless fabric of this vision,
The cloud-capp’d tow’rs, the gorgeous palaces,
The solemn temples, the great globe itself,
Yea, all which it inherit, shall dissolve,
And, like this insubstantial pageant faded,
Leave not a rack behind. We are such stuff
As dreams are made on; and our little life
Is rounded with a sleep.
In a completely different vein, in 2014, the Supreme Court ended the existence of the Federal Circuit’s previous standard for indefiniteness. Following Nautilus, Inc. v. Biosig Instruments, Inc., claims are indefinite if they “fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention” in light of the specification and prosecution history. Nautilus thus replaced the Federal Circuit’s previous “insolubly ambiguous” standard and lowered the hurdle for invalidating patent claims for being indefinite. Shakespeare surely would have appreciated the irony of the Supreme Court essentially ruling that the earlier definiteness standard was itself unclear—much like an “insubstantial pageant faded” whose uncertain boundaries produced claim scope that often “melted into air, into thin air.”
The new Nautilus standard has significantly impacted some cases, as in the 2015 decision from the Federal Circuit inDow Chemical Co. v. Nova Chemical Corps. (Canada). There, claims that were not indefinite under the old standard were ruled by the Court of Appeals to be indefinite under the new standard.
However, the new standard also frequently produces an indefiniteness outcome that is identical to what would have been expected prior to Nautilus, perhaps providing a rebuttal to some of Shakespeare’s musings on the nature of existence. One case in point is Magistrate Judge Paul Grewal’s recent order in Silicon Laboratories, Inc. v. Cresta Technology Corporation, Case No. 14-cv-02337-PSG (N.D. Cal. Mar. 1, 2016), denying Cresta Technology Corp.’s motion for summary judgment as to indefiniteness.
Claims 1 and 11 of U.S. Patent No. 6,137,372 asserted in Silicon Laboratories cover methods for operating a wireless communication system with two capacitance circuits. Each of these claims includes a limitation of achieving a “relatively linear” circuit behavior for the second capacitance circuit over a selected frequency range. CrestaTech argued that the claims are indefinite because they fail to teach a person of ordinary skill how to determine whether circuit behavior is “relatively linear.”
Magistrate Judge Grewal disagreed, finding that the disclosure “teaches exactly what to do to achieve this desired relative linearity” by using a plurality of capacitance circuits, and citing to portions of the specification which teach that using multiple capacitance circuits “provides a substantially linear circuit, with linearity improving as more circuits are utilized. . . so as to provide a relatively linear relationship.” Thus, the District Court deemed the intrinsic evidence to clearly instruct the ordinarily skilled artisan on how to practice—and not practice—the claimed methods. As Magistrate Judge Grewal succinctly described the situation: “Use two or more capacitance circuits, and you’re in. Use one, and you’re out.”
In reaching his decision, Magistrate Judge Grewal rejected CrestaTech’s various arguments that there is ambiguity in the specification. For example, CrestaTech argued that figures of the patent teach two methods of determining relative linearity, which would leave the skilled artisan to guess at what exactly the relatively linear relationship required. But Magistrate Judge Grewal found that the figures in fact reflect a single method of using two or more capacitance circuits, rather than two methods. The District Court noted that this stands in contrast to Dow Chemical, where the possibility of using multiple methods for determining slope gave the Federal Circuit pause as to the definiteness of a claim.
The outcome of Silicon Laboratories highlights the continued importance, under the Nautilus indefiniteness standard, of clearly articulating in the specification a single method by which a skilled artisan can practice the claimed method, and of eliminating ambiguities that might leave the skilled artisan guessing how to do so. Stated another way, patent claims “are not such stuff as dreams are made on” when they are definitively tied to a disclosure in the specification.