In 2005, the United States Court of Appeals for the Federal Circuit sat en banc to consider how patent claims should be construed and issued a decision that expressly rejected some of its prior decisions as having improperly broadened the scope of patents. Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (en banc). It described how the rejected approach of starting with the plain meaning rather than how terms are used in the specification could “systematically cause the construction of the claim to be unduly expansive.”

It has now been several years since the Phillips decision, and we have had the opportunity to see whether application of the principles articulated in Phillips has affected the results in subsequent cases. While the results in a number of subsequent cases have been affected, the principles articulated in Phillips have received uneven reception, both in the trial courts and at the appellate level. Recent decisions are suggesting that judicial approaches to this issue continue to shift and the fundamental aspect of claim construction addressed by Phillips is still far from settled.

Claim Construction Prior to Phillips

Phillips reviewed, and set standards for, how to read a patent claim. The court had previously articulated the notion that a patent claim should be read from the point of view of one of ordinary skill in the art, so that it would give fair notice to competitors of what was — and was not — within the scope of the claim. See Springs Window Fashions L.P. v. Novo Indus., L.P., 323 F.3d 989, 995 (Fed. Cir. 2003) (“The public notice function of a patent and its prosecution history requires that a patentee be held to what he declares during the prosecution of his patent.”) However, over time some judges began applying a “plain meaning” analysis that in most instances results in an arguably broader claim construction. The Federal Circuit in Texas Digital Sys., Inc. v. Telegenix, Inc., 308 F.3d 1193, 1202-03 (Fed. Cir. 2002) emphasized that both English language terms and technical terms in the claims should be given the full breadth of definitions attributed to them by dictionaries and treatises. The only time a more narrow definition was to be applied was when the patent holder has made a “clear disavowal of claim scope” in the patent specification or during its prosecution. Id. at 1204. The court cautioned against even reviewing the patent specification and prosecution history prior to arriving at the ordinary meaning of claim terms, lest error ensue. Id.

The result of this now out-of-favor approach can be illustrated by reference to the decision in Inverness Medical Switzerland GmbH v. Warner Lambert Co., 309 F.3d 1373, 1378-79 (Fed. Cir. 2002). In that case, the Federal Circuit applied the plain meaning analysis and concluded that the term “on” in the phrase “on said test strip” should be construed most broadly as not just including surface deposition (i.e. “on”), but also including impregnating the test strip with the reagent (i.e., “in”). The court reached this conclusion by citing a dictionary definition of “on” as a “function word to indicate presence within.” However, the usage example Webster’s Dictionary provides of this “on” is of being on a jury. (Webster’s Encyclopedic Unabridged Dictionary of the English Language 1005 (1994)). The court reached this construction despite the fact that the patent specification taught only surface deposition, and described how surface deposition was “preferable” to impregnating the carrier.

Phillips on Claim Construction

Phillips disapproved of the Texas Digital and Inverness Medical decisions, and enunciated the following approach to claim construction. Instead of starting with dictionaries and treatises, the court instructed to use the patent specification as a glossary for the claim language. The Phillips court adopted the language of prior Federal Circuit decisions that instructed that the patent specification is “the single best guide to the meaning of a disputed term,” and that the patent specification “acts as a dictionary when it expressly defines terms used in the claims or when it defines terms by implication.” The en banc panel also cited the Echostar case, which held that “even when guidance is not provided in explicit definitional format, the specification may define claim terms by implication such that the meaning may be found in or ascertained by a reading of the patent documents.” 415 F.3d at 1321 (citing Irdeto Access, Inc. v. Echostar Satellite Corp., 383 F.3d 1295, 1300 (Fed. Cir. 2004)).

Accordingly, a court engaged in claim construction should now do a close reading of the entire specification for both implicit and explicit definitions and apply both during the claim construction phase. The courts should not “elevate” dictionaries and treatises to such prominence.

Claim Construction Since Phillips

We now have four years of caselaw applying Phillips, and so it seems fair time to ask whether Phillips has impacted just the analysis, or the results, in subsequent cases. Based on a review of the Federal Circuit decisions over that time period, it appears that Phillips substantively has impacted the outcome in the majority of decisions issued by the Federal Circuit, but there continues to be a minority of decisions that apply the pre-Phillips clear disavowal case holdings. Accordingly, we have come since Phillips to a regime where when the Phillips analysis is applied, the claims often are construed to cover only what the inventor described in the specification; however, either the Phillips analysis is not always applied or the courts are beginning to better define the limits of the Phillips decision.

One example of a post-Phillips analysis is provided in Nystrom v. Trex Co., 424 F.3d 1136 (Fed. Cir. 2005), in which the question was whether a patent on assembling boards into a floor or deck could cover composite-based decking materials. The Federal Circuit concluded that when the claims recited a “board” they were limited to a wooden board, because while the specification acknowledged that other building materials existed, every teaching in the specification was about cutting lumber into logs. This trumped a dictionary definition offered by the plaintiff that described a “board” as “[a] flat piece of wood or similarly rigid material adapted for a special use.”

Since Phillips, the Federal Circuit has issued several decisions involving information technologies in which the claim construction essentially limits the claims to the technical milieu in which the inventor was working. First, there are a number of cases in which the claims have been limited to particular system architectures. For example, in Mangosoft, Inc. v. Oracle Corp., 525 F.3d 1327 (Fed. Cir. 2008), the court construed “local” in the context of a computer system to mean just an internal hard drive and not peripherals of that node. In doing so, it rejected the plaintiff’s proposed construction, which “would read ‘local’ to mean something beyond the breadth of anything in the claims or the specification.… The problem is that nothing in the intrinsic record describes or supports such an expansive meaning.” In InPro II Licensing, S.A.R.L. v. T-Mobile USA, Inc., 450 F.3d 1350 (Fed. Cir. 2006), the court held that “host interface” for a personal digital assistant was limited to a parallel bus interface, where only such an interface was taught, and a preference for it over a serial bus was emphasized. Similarly, in Verizon Services Corp. v. Vonage Holdings Corp., 503 F.3d 1295 (Fed. Cir. 2007), the term “local wireless” was limited to within a few feet of a base station based on statements in a related patent.

In On Demand Machine Corp. v. Ingram Industries, Inc., 442 F.3d 1331 (Fed. Cir. 2006) and, Inc., v. Federated Department Stores, Inc., 527 F.3d 1300 (Fed. Cir. 2008) the Federal Circuit looked at various types of sales operations, and concluded in one case that when the claims used “customer” a retail customer was meant, not someone shopping on the Internet, and that in the other case, when a point of sale was referred to, it too referred to retail purchases.

A third set of examples is found in the networking cases of Microsoft Corp. v. Multi-Tech Sys., Inc., 357 F.3d 1340 (Fed. Cir. 2004) and Netcraft Corp. v. eBay, Inc., 549 F.3d 1394 (Fed. Cir. 2008). In each case, the claims were limited to the communications environments from which they had originated. For example, in Multi-Tech, the terms “sending,” “transmitting” and “receiving” were limited to communicating data packets over a direct point-to-point telephone line and excluding transmission over a packetswitched network because the specification “repeatedly and consistently describes” the transmission of packets over a telephone line.” Similarly, in Netcraft, the term “communications link” was limited to Internet access provided by an Internet Service Provider.

Despite the above cases, which along with other similar decisions since Phillips seem to suggest a strong trend towards narrower claim constructions than would have been reached in the pre-Phillips era, there are also some very recent decisions that suggest that this trend is not all encompassing.

For example, in each of two recent cases, the court rejected a narrow claim interpretation based on citation to pre- Phillips caselaw and an objection that the prosecution of the patent in suit did not clearly disclaim claim scope such that the narrow construction was appropriate. In Cordis Corp. v. Boston Scientific Corp., 561 F.3d 1319 (Fed. Cir. 2009), the claim term at issue related to a stent with pairs of reinforcing struts. The specification disclosed only pairs of struts that were in phase, and the question was whether claim language, added during prosecution to distinguish over art showing pairs of struts that were out of phase, was a disclaimer of scope. The Federal Circuit found the amendment over the prior art and subsequent allowance did not constitute a “clear and unmistakable” disclaimer of claim scope and declined to limit the claims to the type of stent design disclosed. In so holding, the court cited both Phillips and Inverness Medical, the 2002 case whose analysis had been critiqued in Phillips. Similarly, in University of Pittsburgh v. Hedrick, 573 F.3d 1290 (Fed. Cir. 2009), the court also held that there had not been “a clear and unmistakable disavowal of [claim] scope” during prosecution. In that case, the claims were directed to adipose-derived stem cells that can differentiate into specific types of cells. During prosecution the applicant received a rejection over prior art teaching stem cells derived from bone marrow. They submitted a paper showing that adipose derived cells differed in their intrinsic properties from mesenchymal cells. The examiner stated agreement with this proposition, and found the claims ready for allowance. The Federal Circuit did not find clear disavowal of coverage of mesenchymal cells. These two cases suggest either that Phillips should not be read as changing the “clear disavowal” rule as applied to the prosecution history during claim construction, or that the prosecution history in these cases was vague enough that the limits of construing the claim in light of the prosecution history had been reached.