The Claims section of a patent describes the metes and bounds of the patent rights. Each Claim is a single (usually run-on) sentence at the end of the patent. The Claims section of a patent is analogous to a description of land being conveyed in a deed: where Claims define the boundaries of an invention, the land description defines the boundaries of a property.
The name of the game is the Claim.
Patent Claims demarcate the limits of the invention. An infringer infringes a patent by making, selling, importing, using, or offering to sell the invention—as described by the Claims—after the date the patent has issued. Understanding the scope of the Claims, therefore, is vital. However, the technical-legal run-on language of the Claims is difficult to parse. So, who gets to decide what the patent Claims mean and by what process?
In patent litigation, the judge, not the jury, decides what the Claims mean. Claim interpretation, i.e. construction, is performed by the trial court, early on in litigation, in what is called a Markman hearing. In Markman v. Westview Instruments, the Supreme Court held that Claim construction, like contract construction, was to be done by the trial judge, rather than the fact-finder (e.g., jury), because it is a matter of textual interpretation best suited to judges.
Claim interpretation during a Markman hearing is performed with the least context necessary to interpret the Claims.
People use context to address linguistic ambiguity. For example, the spoken phrase "it's time to, eat Grandma!" even if text-messaged to a group without the all-important comma, will be understood by recipients through context.1 Comma or not, recipients, in the context of a family dinner and universal human values, will understand the message is telling Grandma it is time for dinner (and not the grim alternative meaning).
Claim construction also uses context to address ambiguous Claim terms. Generally, the level of context employed by the judge broadens only when a term or phrase is ambiguous. First, Claim terms are understood according to their plain meaning and context within the Claims. Second, context for Claim term meaning is provided by the Specification (i.e., the rest of the patent). Third, context is provided by USPTO records documenting the examination history of the patent. Finally, if the Claim term remains ambiguous, context is provided by extrinsic evidence. A judge's reliance upon expert witnesses and extrinsic evidence to understand technical terms during Claim construction is what the Supreme Court calls "subsidiary fact-finding." See Teva v. Sandoz.
In our experience, a patent holder's presentation during a Markman hearing is critical. As mentioned above, this is the phase of litigation where parties are given an opportunity to present their arguments to the court regarding Claim language. The purpose is to resolve any disputes of how the Claim's terms should be interpreted. If the parties disagree on the meanings of Claim terms, they would have conferred well before the hearing, discussed differing constructions, and then briefed the issues. In other words, before the Markman hearing, the judge is aware of the parties' positions on construction.
Still, walking the judge through intrinsic evidence (e.g., patent Specification, drawings or prosecution history) can sway the judge in your direction. For instance, you may consider showing the judge visuals of various patent drawings, or walk through the patent's prosecution history, specifically if the drawings and patent history align with your proposed construction. Indeed, the intrinsic record is the primary source of Claim construction, so parties should ensure that they clearly demonstrate how the intrinsic evidence supports their proposed construction.
In a small number of cases, Claim construction is controversial and dispositive (i.e., determining the outcome of the trial). These cases may be appealed, for Claim construction, to the Court of Appeals for the Federal Circuit. But how does the appellate court determine the Claim meaning?
Legal appeals address questions of law and fact differently.
Typically, appellate review of questions of law is de novo. An appellate court addresses a legal question from scratch, without deference to the trial court. Conversely, appellate review of questions of fact are only set aside in appeal if found to be "clearly erroneous." FRCP 52(a)(6).
A judge may decide questions of law and fact (using extrinsic evidence or subsidiary fact-finding) during a Markman hearing; so what standard of review on appeal is appropriate when Claim construction is appealed?
In Teva v. Sandoz, the Supreme Court addressed the question of whether Claim construction is reviewable under de novo or clearly erroneous standards. The short unhelpful, but accurate, answer was: "it depends"...
The Teva court held that where only intrinsic evidence(e.g., context from the Claims, Specification, and examination history) is used in Claim construction, the construction is entirely a legal exercise and review under appeal is de novo. However, where extrinsic evidence, like testimony from a technical expert, is used, those subsidiary fact-finding exercises are entitled to deference at the appellate stage and can only be set aside if found to be clearly erroneous.
The holding is intended to allow the trial courts to do what they do best—create a factual basis, and the appellate courts do what they do best—decide legal questions. An additional benefit in deferring to trial court interpretations for terms decided using extrinsic evidence is that these—very technical terms which are inscrutable without the expert help—will not change meaning on appeal. This protects reasonably held beliefs about the facts of a case which are formed at the trial court stage.
Footnote
1 Without this comma, the phrase is an assertion of the speaker's immediate cannibalistic desire to eat his grandmother.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
