Master The Supreme Court held that patent claim construction is a matter of law for the judge, not a question for the jury. with this comprehensive case brief.
Markman v. Westview Instruments, Inc. is a foundational Supreme Court decision that reshaped the allocation of decision-making authority in patent litigation. Before Markman, federal courts often allowed juries to interpret disputed patent claim terms and to determine infringement in a single proceeding. The Supreme Court's unanimous opinion clarified that construing the language of patent claims—the process that defines the metes and bounds of a patentee's right—is a matter of law for the court. This doctrinal shift increased the role of the judge and promoted uniformity and predictability in patent law.
For law students and practitioners alike, Markman is central to understanding modern patent practice. It gave rise to the now-routine "Markman hearing," a pretrial proceeding in which parties present evidence and argument on the meaning of disputed claim terms, enabling the judge to define the legal scope of the patent before the factfinder (often a jury) decides infringement and damages. The decision also reflects deep Seventh Amendment analysis and functional considerations about judicial competence and the need for consistent claim scope across cases.
Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996)
Herbert Markman owned a patent on a computerized inventory control and reporting system used in retail settings (including dry-cleaning establishments). He sued Westview Instruments, Inc., alleging that Westview's point-of-sale system infringed his patent. The core dispute centered on the meaning of the claim term "inventory," which Markman argued encompassed the tracking of both goods and cash receipts. Westview contended that the patent used "inventory" to refer only to physical articles of merchandise, so its system, which primarily tracked financial information and sales data rather than the movement of goods, did not infringe. At trial, the district court allowed the jury to consider claim meaning and infringement; the jury found for Markman. The court then granted judgment as a matter of law (JMOL) for Westview after construing "inventory" to exclude cash receipts and to be limited to tracking actual articles of inventory—under which construction, Westview's system did not infringe. On appeal, the Federal Circuit (en banc) held that claim construction is a matter of law for the court, affirmed the district court's construction, and sustained the JMOL for Westview. The Supreme Court granted certiorari and affirmed.
Whether the interpretation of patent claim terms (claim construction) is a question of law for the court, or a question of fact for the jury, under the Seventh Amendment and general principles of adjudication.
Patent claim construction—i.e., interpreting the meaning and scope of patent claim language—is a matter of law to be decided by the court, not by a jury. The Seventh Amendment does not require that juries construe patent claims. In construing claims, courts may consider intrinsic evidence (the claims, specification, and prosecution history) and, where helpful, extrinsic evidence (e.g., expert testimony and treatises), but the ultimate construction remains a legal determination for the judge.
The Supreme Court affirmed the Federal Circuit and held that the construction of patent claims is exclusively for the court. The Seventh Amendment does not mandate that juries interpret patent claim language.
The Court conducted a historical and functional analysis. Historically, at common law, the construction of written instruments—such as deeds, contracts, and statutes—was treated as a question of law for judges. Patents are written instruments, and their claims delineate the legal boundaries of the patentee's rights; thus, their interpretation aligns with the traditional judicial function. English and early American practice reflected judges instructing juries on the meaning of patent documents while leaving to juries factual determinations like infringement and damages. The Court found no historical basis for a jury right to construe claim language. Functionally, the Court emphasized that judges are better equipped to interpret complex written documents, particularly when uniformity across cases is essential. Because the meaning of a patent claim affects subsequent cases and parties, assigning claim construction to judges promotes consistent outcomes and predictability in the national patent system. The Court recognized that claim construction may involve assessing extrinsic evidence; however, it characterized this as aiding the court's understanding of the technology and the usage of terms, not as transforming claim construction into a jury question. Accordingly, the Seventh Amendment posed no obstacle to assigning this task to the court, and the district court properly set aside the jury's verdict based on its independent claim construction.
Markman established that claim construction is for the judge, catalyzing the widespread use of pretrial Markman hearings and ensuring that the legal scope of a patent is determined before the factfinder assesses infringement and damages. The case advances uniformity and predictability by centralizing interpretive authority with the court, which in turn facilitates consistent appellate review. For law students, Markman is indispensable: it defines the structure of modern patent trials, shapes litigation strategy, and interacts with later cases (e.g., Teva v. Sandoz) addressing how appellate courts review claim construction. While Teva later clarified that subsidiary factual findings underlying claim construction are reviewed for clear error, Markman's allocation of claim construction to judges remains the bedrock of patent adjudication.
Claim construction is the court's legal interpretation of the words of the patent claims to define the scope of the patentee's rights. Infringement is a subsequent, usually fact-intensive comparison of the construed claims to the accused product or process. Under Markman, the judge first decides what the claims mean; then, the factfinder (often a jury) decides whether the accused device falls within that interpreted scope.
Markman held that the Seventh Amendment does not require juries to interpret patent claim terms. The Court concluded that interpreting written instruments is historically and functionally a judicial task. Juries still decide factual issues like infringement and damages, but the legal meaning of the claims is set by the judge.
It institutionalized the pretrial 'Markman hearing,' at which parties present intrinsic and, if helpful, extrinsic evidence on disputed claim terms. The court then issues a claim construction order that frames the rest of the case, often influencing summary judgment, trial strategy, settlement posture, and the likelihood of success at trial.
Yes. Courts may consider extrinsic evidence—including expert testimony, dictionaries, and technical treatises—to aid understanding. However, intrinsic evidence (claims, specification, prosecution history) remains primary. Extrinsic sources cannot contradict unambiguous intrinsic evidence; they serve as tools to inform, not to control, the court's legal construction.
Teva v. Sandoz (2015) refined the standard of appellate review for claim construction. While Markman allocates claim construction to judges, Teva held that appellate courts must review a district court's subsidiary factual findings underlying claim construction for clear error, while the ultimate legal interpretation remains reviewed de novo. The allocation to judges set by Markman remains intact.
Markman's allocation applies across patent types and to all claim terms. Whether claims involve mechanical, chemical, biotech, or software inventions, the judge decides their meaning as a matter of law, sometimes assisted by limited factual determinations to understand how a person of ordinary skill in the art would read the claims.
Markman v. Westview Instruments, Inc. reoriented patent trials by assigning the legal task of claim construction to the court. By clarifying that judges, not juries, interpret the language that defines the boundaries of a patent, the Supreme Court advanced uniformity, predictability, and efficiency in patent adjudication.
For students and litigators, the case underscores the centrality of claim construction to case outcomes and explains the procedural architecture of modern patent cases. Together with later decisions on methodology and standards of review, Markman remains a cornerstone of patent litigation strategy and doctrine.
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