The Supreme Court, in Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996), determined that claim construction is a matter of law exclusively for the courts, and is not a factual matter for juries (although it did recognize that claim construction is somewhat of a “mongrel,” having aspects that are both legal and factual). In Cybor, the Federal Circuit considered what the implication of that finding would be on how it, as an appellate court, would review a trial court’s construction of the claims in a patent. It concluded that because claim construction is a matter of law, it would review a district court’s construction of the terms in a patent de novo, meaning without any deference to the lower court’s conclusion. This has been the state of the law for some time now.
The implications of the Cybor decision are significant to patent holders and those accused of infringement. As a practical matter, parties to a lawsuit have come to view a district court’s claim construction as a somewhat intermediate position. After all, if the Federal Circuit will give no deference to the district court’s conclusions, there is a significant possibility that those conclusions could be reversed on appeal. Fair or not, the perception of the Federal Circuit among some practitioners is that a trial court’s claim construction only has a 50/50 chance of being affirmed on appeal. (For some interesting studies of Federal Circuit reversal rates, see here, here, and here). Many have complained that this uncertainty discourages settlement, because the “losing” side on the claim construction issue often feels that it will be “vindicated” on appeal.
On the other hand, by having the Federal Circuit have the “final say” on claim construction, it promotes more consistency and, hopefully, better results, as the Federal Circuit is often far more familiar with claim construction issues than many district courts and they (and their clerks) are often better versed in the technologies described in these patents.
Patent holders are also fearful that if claim construction is not reviewed de novo, an unfavorable claim construction by a district court may be very difficult to overcome and could affect how a particular term is construed in other patents held by the patentee. If the Federal Circuit has the final say, a patentee has more options. For instance, it can appeal to the Federal Circuit a get a fresh look at the issue, or it can settle the case with a realistic hope that the Federal Circuit in a later case would not be particularly beholden to how a district court in a previous case construed a claim term.
Thus, this case will be particularly important for parties in patent litigation. It will be very interesting to listen to the oral argument in the Lighting Ballast case and see what the Federal Circuit ultimately decides. This may, in the end, be another issue that the Supreme Court will decide to weigh in on.