A Markman hearing is an evidentiary hearing used in US Federal District Court in patent dispute cases. The hearing is named from the 1996 US Supreme Court case of Markman v. Westview Instruments, Inc. It is conducted when a plaintiff is alleging patent infringement, and the judge must decide whether the language in the plaintiff’s patent claim would prevent the defendant from selling or using the same type of invention.
In the Markman case, the plaintiff had patented a system to barcode dry cleaning tickets through an optical scanner. His system allowed a dry cleaning service to track its inventory and detect duplications and errors. Defendant Westfield’s system also used barcode tickets and an optical scanner.
The jury in Markman found for the plaintiff. The district court judge then entered a “directed verdict” for the defendant, ruling that the Westfield system had not infringed Markman’s patent, as it could not track inventory like Markman's system. The directed verdict meant that the judge believed the jury’s decision was incorrect as a matter of law.
The Supreme Court held that the interpretation of that portion of a patent which describes the scope of the patent-holder’s rights is left to the court. It found that the district court’s decision was not inconsistent with the Seventh Amendment constitutional guarantee that a jury decide factual matters in a case. The Court noted that under common law practice at the time of the drafting of the Constitution, juries did not decide how to construe the technical language of patent claims.
Following the Court’s decision, federal district courts began holding a Markman hearing, sometimes called a “claim construction hearing,” in patent infringemnt cases. The hearings are held prior to trial when no jury is present. In reaching a decision about the scope of a patent claim, the court looks at the written description that accompanies the patent claim and the history of the patent application. In determining the meaning of technical terms of art, the court looks to Standard English dictionaries and the affidavits of experts in the field at issue.
Most district courts have preparation guidelines for a Markman hearing. They require a legal memorandum from the parties in support of their positions and a proposed draft of the plaintiff’s claim of patent that is understandable to a jury. Legal memoranda must include a copy of the patent at issue, affidavits of any persons skilled in the art of which the disputed terms are involved, and a list of all witnesses and exhibits. Today, a Markman hearing often results in the dismissal or settlement of patent infringement claims before it goes to trial.