Facts of the Case

Herbert Markman owns the patent to a system that tracks clothing through the dry-cleaning process using a keyboard and data processor to generate transaction records, including a bar code readable by optical detectors. According to the patent's claim, the portion of the patent document that defines the patentee's rights, Markman's product can "maintain an inventory total" and "detect and localize spurious additions to inventory." Westview Instruments, Inc.'s product also uses a keyboard and processor and lists dry-cleaning charges on bar-coded tickets that can be read by optical detectors. In an infringement suit, after hearing an expert witness testify about the meaning of the claim's language, a jury found that Westview's product had infringed Markman's patent. However, the District Court directed a verdict for Westview on the ground that its device is unable to track "inventory" as that term is used in the claim. In affirming, the Court of Appeals held that the interpretation of claim terms is the exclusive province of the court and that the Seventh Amendment right to a jury trial is consistent with that conclusion.

Question

Is the interpretation of a patent's claim, the portion of the patent document that defines the scope of the patentee's rights, a matter of fact to be decided by jurors?

Conclusion

No. In a unanimous decision, authored by Justice David H. Souter, the Court held that the construction of a patent, including terms of art within its claim, is exclusively within the province of the court. Justice Souter wrote that "judges, not juries, are the better suited to find the acquired meaning of patent terms."