In 1996, the United States Supreme Court decided the case of Markman, et al. v. Westview Instruments, Inc., et al. The case held that the question of interpretation of patent claim language is an issue for the judge, not the jury. As the Supreme Court noted, patent lawsuits charge infringement of patent claims. Every patent infringement claim is based on the plaintiff’s assertion the defendant is making, using or selling a product that practices every element of a patent claim. Thus, prevailing in a patent infringement action requires that the court understand the asserted patent claims the same way the plaintiff does. Courts come to this understanding through claim construction which takes place in the Markman hearing.
Claim construction begins with the language of the claim. The claim terms are presumed to mean what they say. Thus, it is common for the courts to indicate that claim terms are given their ordinary and customary meanings. Courts should look to the words themselves to define the scope of the patented invention.