The U.S. Supreme Court clarified an important patent infringement issue when it held that courts, not juries, must interpret patent claims. In Markman v. Westview Instruments Inc., 116 S.Ct. 1384 (April 23, 1996), the court ruled that a trial judge determines what a patent covers, and then a jury decides whether the patent has been infringed.

However, although the jury makes it decisions after hearing all the evidence at trial, the court did not say when the judge's claim interpretation should take place. Attorneys and litigants in patent infringement cases are now faced with the strategic decision of when to ask the court to interpret a patent's claims.

Claim interpretation commonly occurs at one of three stages: at an early "Markman hearing," before extensive discovery and filing of dispositive motions; simultaneously with a motion for summary judgment; or after the evidence has been presented at trial and before the jury has been instructed. Each stage has its advantages and disadvantages -- and an attorney choice will depend on case specifics. Before advising a client on when to seek the court's claim interpretation, therefore, counsel should consider the consequences of each timing option.

Defining the scope of the invention disclosed by a patent is often dispositive. For example, in Markman, the plaintiff held a patent for a dry-cleaning inventory-control method. Whether the defendant's system infringed the patent boiled down to the meaning of "inventory." If the terms referred to clothing, the patent was not infringed. After trial -- and despite the jury's infringement finding -- the district court interpreted inventory to include clothing, and granted the defendant's motion for judgment as a matter of law. The U.S. Court of Appeals for the Federal Circuit and the U.S. Supreme Court both affirmed, ruling that claim interpretation is the court's exclusive province.

In a case like Markman, where claim interpretation is likely to be dispositive, it makes sense to hold a hearing early -- either in the context of a motion for preliminary injunction or separately. In Markman, an early claim interpretation would have obviated the full trial and jury deliberations that the trial judge ultimately negated. Because a claim-interpretation order will often put the case in a posture for summary judgment, counsel representing defendants in patent-infringement cases should think about requesting early claim construction -- especially since courts generally welcome the opportunity to dispose of cases early.

Some courts will consider at such hearings only counsel's arguments and papers, supported by expert declarations. Others will allow witness examinations. In either case, the court will produce an interpretation order that addresses the first step of the infringement analysis, the meaning and scope of the disputed claim terms. In both Loral Fairchild Corp. v. Victor Co. of Japan Ltd., 911 F.Supp. 76 (E.D.N.Y. 1996), and Elf Atochem N. America Inc. v. Libbey-Owens-Ford Co. Inc., 894 F. Supp. 844, 850 (D. Del. 1995), the courts held two-day bench trial on claim interpretation alone, and issued orders establishing only the meaning of the terms.

In some cases, the parties may even agree that infringement hinges on which of two proffered definitions the court adopts. Then the interpretation order can be a de facto determination of infringement or noninfringement, and summary judgment based solely on claim interpretation can be appropriate. For example, in Athletic Alternatives Inc. v. Prince Mfg. Inc., 73 F.3d 1573 (Fed. Cir. 1996), the parties did not dispute any relevant facts regarding the accused product, but they disagreed about which of two patent-claim meanings was proper. By adopting the defendant's interpretation, the court disposed of the case by entering summary judgment, since the parties had stipulated to the facts surrounding the accused product.

Even if an early interpretation order does not dispose of a case, it may help narrow discovery and define issues, as well as provide a framework for pretrial and trial preparations.

For example, in American Permahedge Inc v. Barcana, Inc., 901 F.Supp. 155, 159-60 (S.D.N.Y. 1995), the plaintiff had a patent for an artificial hedge made of twisted wires resembling a twig, through which fibers resembling evergreen needles were threaded. When ruling on the plaintiff's motion for a preliminary injunction, the court construed two key claim terms that referred to the position of the fibers in relation to the wires. Later, when the defendant moved for summary judgment, the parties and the court needed only to refer to that order and consider the accused artificial hedge. Because the court had already said the disputed claim terms required the needles to extend perpendicularly from the twig wire, and the accused artificial hedge's needles extended at an angle from the twig wire, there was no infringement.

One drawback to an early Markman hearing stems from courts' reluctance to consider new theories based on claim terms that were not the subject of the early hearing. Thus, the parties may be locked into a single defense or liability theory.

For example, in Loral Fairchild, the patentee, throughout the litigation and during the Markman hearing, had asserted that Claims 7 and 8 merely described methods of operating the structure set forth in Claim 1; thus, Claims 7 and 8 could not be infringed absent infringement of Claim 1. After a Markman hearing in which the court construed Claim 1 more narrowly than the patentee had advocated, the patentee tried to argue that Claims 7 and 8 were broader than Claim 1 and thus could be infringed independently. But the court precluded the patentee from making the new argument during the remainder of the litigation. Thus, before proceeding with an early Markman hearing, parties should consider any alternative theories of claim construction they may wish to advance.

As an alternative to an early Markman hearing, a party may ask the court to interpret patent claims in the context of a motion for summary judgment, in which the court addresses both steps of the infringement analysis; claim-term interpretation as well as evidence comparing the terms with the accused device. This approach is appropriate in cases where the parties dispute not only claim interpretation, but also where a genuine issue of disputed fact exists regarding whether the accused device contains each claim element, however they are interpreted.

One benefit of requesting claim interpretation at this point is that parties have had the opportunity to undertake extensive discovery. Also, a party can save the court's time by requesting consideration of the entire infringement issue in one motion, instead of moving first for claim interpretation and then again for summary judgment based on the court's.