Authored by Gerson S. Panitch
In 1990, Giles Rich, then Chief Judge of the Federal Circuit, proclaimed, "The name of the game is the claim."1 Indeed, more than a decade of precedent both before and after made clear that the scope of a patent rested primarily in the words of its numbered patent claims. Patent claims written narrowly were typically afforded limited protection. Broadly crafted claims regularly resulted in expansive patent protection.
Thus over the last three decades, experienced patent drafters honed the skill of crafting broadly worded claims to cover more than what a patent expressly describes. For example, if a technical description in a patent disclosed only "a serial bus," it would not have been unusual to claim that structure as "an interface." In this way, the patent drafter hoped to cover not only all forms of serial busses, but also parallel busses and all other types of interfaces a competitor might employ.
Companies invested their patenting dollars in elaborate claiming strategies, placing less emphasis on the technical description and background parts of their patent applications. There seemed little need to do otherwise. For the name of the game was truly the claim.
Then, two years ago, the winds abruptly began to shift with the Federal Circuit's decision in Phillips v. AWH.2 In the wake of that en banc decision, dozens of later decisions confirmed a revolution underway in patent law. No longer would the judiciary afford deference to broad claim language. For the Federal Circuit began developing a new body of case law curtailing patent rights where language in a patent suggested that an invention was narrower than the actual words in the claims. Applying this new rationale, the Federal Circuit interpreted a claimed "board" as requiring a board cut from a log and not boards made of synthetic materials.3 It interpreted the word "fiberfill" as requiring only synthetic and not natural material.4 And it interpreted a claimed "host interface" as referring only to a "parallel bus interface," and not a serial-bus interface.5 These limiting interpretations each resulted from statements made by the inventors in their patent specifications. And in each of these examples—as in many recent others—the Federal Circuit's interpretation led to findings of no infringement in cases where the words of the claims alone counseled the opposite conclusion.
The upshot of this new trend is twofold: Patent drafters must invest more effort in crafting patent specifications so as not to infect their applications with inherent narrowness. And litigators must realize that patent claims might no longer mean what they say. The name of the game is now the entire patent.
It Started with Phillips
The Federal Circuit's July 2005 decision in Phillips v. AWH was unremarkable in its outcome. It reversed a district court's interpretation of claimed "baffles" as requiring a particular angular orientation. This outcome made perfect sense, since the claims themselves did not recite any particular angular orientation. Yet more significant than the outcome was a shift in rationale. For the first time, an en banc panel of the Federal Circuit signaled that the words of patent claims could not be interpreted in a manner divorced from the context of the entire patent. In doing so, the Federal Circuit elevated the patent specification as the primary guide for interpreting patent claims. And since the issue of patent claim interpretation is a question of law, the Phillips decision began a new era where courts could now go so far as to dispose of patent cases without a jury, if in a court's view the patent specification supported a narrow claim interpretation under which no reasonable jury could find infringement.
Consistent with the Phillips rationale, the Federal Circuit began scrutinizing patent claims like never before. But this time, unlike the unremarkable outcome in Phillips, decision after decision appeared to insert into the claims limitations nowhere found within the words of the claims themselves. These cases fall into six categories.
1. Vague Claim Terms Pose a Risk of Narrow Interpretation
When a claim term is vague or subject to multiple interpretations, the first place courts will now look for understanding is the patent specification. And if the patent specification includes a particularly narrow disclosure, that narrowness may infect the claim. For example, when Network Commerce sued CRS and Microsoft, claiming infringement of a patented system for purchasing software or audio files over the Internet, the vague term "download component," proved to be the patent owner's downfall.6 Unable to understand the meaning of that term without resort to the specification, the Federal Circuit concluded that since the only corresponding disclosure in the patent was a download file with three specific boot functions, the claims required those functions. And since CRS and Microsoft's product did not exhibit those three functions, there could be no infringement as a matter of law.
Honeywell International faced a similar fate.7 It invented the use of metal fibers in nonmetallic automotive fuel-system components in order to dissipate dangerous electric charges. It broadly claimed the invention in connection with a "fuel system component," and when ITT Industries incorporated the inventive concept into a fuel-line connector, Honeywell sued for patent infringement. But much to Honeywell's dismay, the Federal Circuit concluded that the term "fuel system component" could be interpreted to cover only fuel filters, and not ITT's fuel-line connectors. Despite Honeywell's written statements during the patenting process supporting a broader interpretation, the Federal Circuit noted at least four occasions where Honeywell's patent used the phrases "this invention" or "the present invention" in connection with fuel filters. Thus, in the Federal Circuit's view, "[w]here, as here, the [inventor's] written description clearly identifies what his invention is, an expression during prosecution that he intends his claims to cover more than what his specification discloses is entitled to little weight."8
The lesson from these exemplary cases becomes clear: When patent claims contain terms that are either generic or subject to multiple meanings, applicants must carefully craft the patent specification in a way that defines those terms broadly. Otherwise, the limited examples of the specification may govern claim interpretation.
2. Disparaging or Distinguishing Comments Might Limit the Claims
When it sued T-Mobile, Inpro II Licensing probably thought it had a clear case of literal infringement.9 Yet the Federal Circuit dashed those hopes because, within the context of the patent specification, a "host interface" could refer only to a parallel-bus interface, and not the serial connection T-Mobile used. In reaching this conclusion, the Federal Circuit noted that the patent referred to prior-art serial connections as "a big drawback," and "very troublesome," and referred to a parallel-bus interface as "a very important feature of the present invention."10 In addition, the Federal Circuit noted that the only embodiment described in the patent used a parallel bus. "Although claims need not be limited to the preferred embodiment," the Federal Circuit explained, "when the invention is more broadly described, neither do the claims enlarge what is patented beyond what the inventor described as the invention."11
In the absence of disparaging statements, a patent's reference to a differing characteristic of the prior art can lead to a narrow claim interpretation. For example, Terlep sued Brinkmann on a patent for solar-powered pathway lighting, with "clear" lenses.12 Since Brinkmann's lens diffused light, the Federal Circuit found no infringement because the summary of the invention distinguished the invention over diffusing lenses.
These examples teach that in a post-Phillips world, the patent itself is probably not the best forum to distinguish the prior art from the invention. And certainly, in a post-Phillips world, one should not negatively characterize the prior art. For such distinctions and disparaging remarks may infect the scope of the claims.
3. Highlighting the Import of a Nonclaimed Feature Might Result in Claim Narrowing
When Atofina sued Great Lakes Chemical on a patent claim reciting a "chromium catalyst," the Federal Circuit interpreted that term as excluding metal oxides or noninert additives.13 In doing so, the Court cited the inventor's use of the word "necessary" when describing that the catalyst should contain solely chromium. In the prosecution history, in response to a rejection by the examiner, Atofina had also highlighted that the claim transition employed the phrase, "consisting essentially of," and that "the present invention makes it possible to employ a catalyst based solely on chromium to carry out a fluorination reaction."14 By referring to a "solely" chromium catalyst as "necessary," Atofina ended up with a claim interpreted more narrowly than it was written.
Curtiss-Wright Flow Control's lot was similar in its suit against Velan over a machine for deheading coke drums.15 Curtiss-Wright claimed an adjustable machine, and Velan's accused infringing machine was adjustable during down time between periods of operation. Yet the Federal Circuit interpreted the word "adjustable" as requiring adjustability "while the machine is in use or operation," and therefore found no infringement. In reaching that conclusion, the court cited, among other things, the fact that the background of the patent discussed hazards occurring during use in the absence of on-the-fly adjustability; and the specification's use of the phrase "critical aspect" to describe the ability to dehead coke drums without having to perform manual operations.16
While in the past, patent practitioners might have routinely emphasized features of an invention with words such as "critical," "necessary," and "important," today they should avoid that language. Otherwise, they run the risk that features so identified might find their way into a court's narrowing claim interpretation.
4. Narrow Examples Without a More General Description Can Reduce Claim Scope
Though the Federal Circuit has repeatedly cautioned against reading features of preferred embodiments into the claims, that rule seems to have a number of significant caveats. For example, if the preferred embodiments contain the broadest description of the invention and the patent lacks more general language, Federal Circuit precedent is prone to imposing unclaimed features of preferred embodiments on the claims. This is what happened to Tapp Pharmaceutical in its suit against Owl Pharmaceutical.17 In an invention for a microparticle injection, the parties disputed the meaning of the word "particle." The Federal Circuit narrowly interpreted a "particle" as requiring both a "drug" and a "drug retaining substance." The court justified its interpretation because in all 31 examples in the patent specification, a particle was described as having both components.18 There was no broader description in the patent aside from those preferred embodiments. As a result, the patent owner was stuck with claims narrowed to the scope of the preferred embodiments.
Aquatex Industries shared a similar experience in its suit against Techniche Solutions over fiberfill batting materials.19 Aquatex included verbiage in its patent mentioning that "the particular fiberfill is not known to be critical. That is, any commercial fiberfill may be used as long as it does not adversely affect the performance of the end composite." But since all the commercial examples in the specification used purely synthetic fiberfill, the Federal Circuit interpreted "fiberfill" in the claims as requiring only synthetic fiberfill and thus remanded the case on the issue of equivalents.20
This new precedent is a splash of cold water to practitioners who craft applications around one or two preferred embodiments without broader characterizations of the invention. Particularly when patent applications identify one or more commercial examples more narrowly than what the inventors consider their invention, this new Federal Circuit precedent suggests that applicants should characterize the invention in broader terms or risk court-imposed claim restrictions.
5. Describing Benefits of the Invention Can Result in Narrowed Protection
In the past, many patent practitioners included a description of unclaimed advantages of the invention in their applications. Under post-Phillips precedent, however, that practice may haunt patent owners as it did Nystrom in his suit against Trex.21 In that case, the invention involved decking boards with rounded-top side edges that aided in water runoff. The broadest claims recited a board, without specifying the material from which the board was made. Nevertheless, the Federal Circuit interpreted the word "board" as requiring a board cut from a log and excluding coverage of Trex's synthetic product. In narrowly interpreting the claims, the Federal Circuit pointed to a statement in the specification explaining that the invention yields a superior product and reduces the amount of scrap in the outermost boards cut from a log. Since this stated advantage of the invention was unachievable unless the board was cut from a log, the Federal Circuit concluded that the claimed "board" was properly limited only to those boards cut from a log.22
The rationale in Nystrom v. Trex provides defense counsel with a new tool to avoid infringement: Scour the patent for stated advantages unachievable by the accused product and advance the source of those advantages as an implied claim requirement.
6. References to Unclaimed Features of "the Invention" May Lead to Narrowing
Even if a patent does not highlight an unclaimed feature as being particularly important or beneficial, the mere association of an unclaimed feature with "the invention" might lead the Federal Circuit to treat the feature as an inherent part of the claims. Cook Biotech learned this lesson the hard way in its suit against Acell.23 That case involved a tissue-grafting method with three independent patent claims. The first two recited urinary bladder tissue delaminated from a muscle layer. The third recited the bladder tissue but did not expressly require any delamination. The Summary of the Invention section of the patent explained that delamination was "typical," suggesting that it was not always needed. Thus, the district court found that Acell's method, which did not delaminate, infringed that third independent claim. But the Federal Circuit reversed, interpreting even the claim that did not recite delaminating as inherently requiring it. In doing so, the Federal Circuit focused on one particular statement in the patent specification, which stated that the urinary bladder tissue "for use in accordance with the present invention is delaminated" from the muscle layers. (Emphasis added.) The Federal Circuit viewed this passage as a "special definition," and as a result concluded as a matter of law that there could be no infringement either literally or under the doctrine of equivalents.24
The lesson of Cook Biotech is harsh. Despite what claims say, if the specification definitively refers to "the invention" as having an additional feature, that feature might be inherently imported into the claims. Perhaps the result would have differed had Cook's patent mentioned that with the invention the bladder tissue "may be" delaminated, as opposed definitively stating that with the invention it "is" delaminated.
Global Trends in Post-Phillip Cases
On a case-by-case basis, some post-Phillips claim-construction decisions may appear inconsistent with each other. But underlying trends are clearly emerging. The Federal Circuit is repeatedly emphasizing that "a word describing patented technology takes its definition from the context in which it was used by the inventor" and that a patent owner is not entitled to a claim construction "divorced from the context of the written description."25
Whether courts will read limitations from the specification into the claims is a function of whether statements in the specification appear to refer to the invention as a whole or whether they refer only to a particular embodiment. "Statements in the specification that describe the invention as a whole rather than statements that describe only a preferred embodiment are more likely to support a limiting definition of a claim term."26
These post-Phillips trends clearly favor accused infringers. Defense attorneys who carefully parse the words of patent specifications for subtleties of language may reap great rewards for their clients accused of infringement. And the Markman proceeding, where courts interpret the claims as a matter of law, now rises to an even higher level of import.
There is something in the post-Phillips case law for everyone. For every Federal Circuit decision reading limitations into claims, there is another where the Federal Circuit refused to do so. Therefore, to advocate effectively during a Markman proceeding, counsel for both parties must be well versed in the subtleties of the Federal Circuit's post-Phillips claim-construction decisions.
And in a post-Phillips world, companies need to consider investing more patent dollars in carefully crafted specifications that contain appropriately broad characterizations of the invention and that are wordsmithed to avoid the risk of infecting the patent claims with inherent narrowness.
Patent drafters should reconsider outdated practices of distinguishing the invention from the prior art in the patent specification, because during litigation, those distinctions, particularly if they are unclaimed, may find their way into narrowing claim interpretations. Similarly, patent drafters should steer clear of characterizing features of the invention as "important." Otherwise, the features so identified may end up being read into claims that do not expressly recite the same features. Finally, and perhaps most difficult, patent drafters need to adopt new writing techniques that avoid definitively associating any particular characteristic with "the invention," unless the characteristic is absolutely necessary. Otherwise, some day down the road, the patent may end up being interpreted in a narrow manner never intended.
The name of the game is no longer just the claim. It's the whole patent.
1 Giles S. Rich, The Extent of the Protection and Interpretation of Claims-American Perspectives, 21 Int'l Rev. Indus. Prop. & Copyright L., 497, 499 (1990) ("To coin a phrase, the name of the game is the claim.").
2 Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005).
3 Nystrom v. TREX Co., 424 F.3d 1136, 1143-45 (Fed. Cir. 2005).
4 Aquatex Indus., Inc. v. Techniche Solutions, 419 F.3d 1374, 1382 (Fed. Cir. 2007).
5 Inpro II Licensing, S.A.R.L. v. T-Mobile USA, Inc., 450 F.3d 1350, 1354-55 (Fed. Cir. 2006).
6 Network Commerce, Inc. v. Microsoft Corp., 422 F.3d 1353 (Fed. Cir. 2005).
7 Honeywell Int'l,, Inc. v. ITT Indus., Inc., 452 F.3d 1312 (Fed. Cir. 2006).
8 Id. at 1319.
9 Inpro II, 450 F.3d at 1350.
10 Id. at 1354.
11 Id. at 1355.
12 Terlep v. Brinkmann Corp., 418 F.3d 1379 (Fed. Cir. 2005).
13 Atofina v. Great Lakes Chem. Corp., 441 F.3d 991, 996-97 (Fed.Cir. 2006).
14 Id. at 997.
15 Curtiss-Wright Flow Control Corp. v. Velan, Inc., 438 F.3d 1374 (Fed. Cir. 2006).
16 Id. at 1379-80.
17 Tap Pharm. Prods., Inc. v. Owl Pharm., L.L.C., 419 F.3d 1346 (Fed. Cir. 2005).
18 Id. at 1353-54.
19 Aquatex, 419 F.3d at 1374..
20 Id. at 1382-83.
21 Nystrom, 424 F.3d at 1136.
22 Id. at 1143-45.
23 Cook Biotech Inc. v. Acell, Inc., 460 F.3d 1365 (Fed. Cir. 2006).
24 Id. at 1374-75.
25 Tap, 419 F.3d at 1354; Nystrom, 424 F.3d 1144-45.
26 Varco, L.P., v. Pason Sys. USA Corp., 436 F.3d 1368 (Fed. Cir. 2006) (quoting C.R. Bard, Inc. v. U.S. Surgical Corp., 388 F.3d 858, 864 (Fed. cir. 2004)).
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