Markman V Westview Instruments Inc.

Short Description

Patent claim construction (interpretation of the terms in patent claims) is a question of law for the judge, not a question of fact for the jury under the Seventh Amendment.

Facts

Herbert Markman held a U.S. reissue patent (No. 33,054) for an “Inventory Control and Reporting System for Dry‑cleaning Stores.” It was a system that used a keyboard, a data processor, bar codes readable by optical detectors, etc. to track clothing through the dry‑cleaning process. The claim language included terms like “maintain an inventory total” and “detect and localize spurious additions to inventory.” Westview Instruments sold a somewhat similar system, but Markman alleged infringement. The jury, after hearing expert testimony about how to interpret the claim terms, found for Markman (i.e., that the Westview product infringed under Markman’s interpretation). The District Court nevertheless granted Westview’s motion for judgment as a matter of law (JMOL), overturning the jury verdict, on grounds that under the court’s own interpretation of “inventory,” Westview’s product did not meet what Markman’s patent claim required. On appeal, the Federal Circuit affirmed that claim construction is a matter for the court. Then Markman petitioned to the U.S. Supreme Court.

Issue / Question

Whether under U.S. law (including the Seventh Amendment) the interpretation (construction) of patent claims terms is a matter of law to be decided by the judge, or whether it is a question of fact for the jury (especially when experts testify about meaning of terms).

Findings / Reasoning

The Supreme Court examined historical common‑law practice around the time of the framing of the Seventh Amendment (late 18th century) and found that judges, not juries, traditionally interpreted written instruments (including patent specifications / claims). The Court held that interpreting terms of art in patent claims is more suitably done by judges, because it involves technical, legal analysis, uniformity and predictability, which are better supported by judicial rather than jury decision‑making. The Court reasoned that allowing juries to interpret claim terms would lead to inconsistent rulings across different cases and make patent rights less stable. Judges are better positioned to read the patent document whole, consider specification, prior art, usage, and expert evidence. The Court distinguished between the legal question of what the claim means (judge) vs factual question whether the accused product falls under that meaning (jury).

Suggestions / Implications

In patent litigation, there are now often so‑called 'Markman hearings' (claim construction hearings) before trial, in which the judge resolves disputed terms of the patent claim. Patent drafters and litigators must carefully define claim terms in clear and precise manner, including definitions in the specification, dictionaries, and possibly usage in the patent history (prosecution history). Parties should present strong intrinsic evidence (patent text, claims, specification, figures) and extrinsic evidence only when necessary. Disputes over meaning of technical terms will be resolved in judge’s claim construction, which can be dispositive of infringement or non-infringement. This decision increases the importance of claim language drafting and encourages early litigation over claim construction, possibly resolving or narrowing issues before full trial.

Judgment / Date

Decided April 23, 1996 – The Supreme Court unanimously (9‑0) held that claim construction is a question of law for the court, not the jury. They affirmed the Federal Circuit decision.