As most patent practitioners know, the appellate court for United States patent cases, the Court of Appeals for the Federal Circuit, reviews decisions on how patent claims should be construed without any deference to the district court, and has the reputation of reversing a large percentage of such decisions. This rule, laid down in an en banc decision of the Court in 1998, may soon undergo important changes. In Lighting Ballast Control LLC v. Philips Electronics North America Corp., No. 12-1014 (Mar. 15, 2013), the United States Court of Appeals for the Federal Circuit has summoned the court en banc to consider the following three questions: “a. Should this court overrule Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448 (Fed. Cir. 1998)? b. Should this court afford deference to any aspect of a district court’s claim construction? c. If so, which aspects should be afforded deference?”
Cybor’s controversial rule has both critics and supporters of some importance, as shown by the amicus briefs so far filed in Lighting Ballast: the American Bar Association, American Intellectual Property Association, Federal Circuit Bar Association, and (to a more nuanced extent, as discussed below) United States of America as amici have urged that Cybor be overruled, while Google, Amazon, Hewlett-Packard, Yahoo!, Cisco, Dell and Microsoft have advocated keeping Cybor the rule. While we wait, it may be interesting to consider a few aspects of the questions facing the Court. First, some of the details of the particular appeal the en banc Court has chosen to rehear are considered. Second, several potentially “factual” aspects of the scope of patent claims are addressed.
The Lighting Ballast Case And “Means-Plus-Function” Claiming
In the nonprecedential panel opinion in Lighting Ballast (now vacated), the unanimous panel reversed a jury verdict of infringement and no invalidity by finding that “voltage source means providing a constant or variable magnitude DC voltage between the DC input terminals” was a “means plus function” element. In doing so, it reversed the district court’s claim construction that had been given to the jury for application to the facts of the case. The panel went on to find a lack of corresponding structure, which rendered the claims indefinite.
The concept of a means plus function element was introduced into American law in the 1952 patent act. Section 112, paragraph 6 of that Act provides that “An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.” (Recently, section 112 paragraph 6 was adorned by statute with the small letter (f), so it is often referred to now as § 112(f).)
In 1994, the Federal Circuit held that if a means plus function element has no “corresponding structure, material, or acts described by the specification,” then claims containing that element are indefinite. In re Donaldson Co., 16 F.3d 1189, 1195 (Fed. Cir. 1994) (en banc) (Rich, J.) (“[I]f one employs means-plus-function language in a claim, one must set forth in the specification an adequate disclosure showing what is meant by that language. If an applicant fails to set forth an adequate disclosure, the applicant has in effect failed to particularly point out and distinctly claim the invention . . . .”). This rule is applied perhaps most often to software patents, where there is an additional rule that requires the corresponding structure to be an “algorithm.” See, e.g., Aristocrat Techs. Australia Pty Ltd. v. International Game Tech., 521 F.3d 1328 (Fed. Cir. 2008).
There is also a line of precedent saying that claims, despite containing the word “means,” can be exempted from § 112 ¶ 6 if such “a claim recites a function, but then goes on to elaborate sufficient structure, material, or acts within the claim itself to perform entirely the recited function.” Sage Prods. Inc. v. Devon Indus. Inc., 126 F.3d 1420, 1427-28 (Fed. Cir. 1997).
The following are some examples of structure found sufficient in precedential Federal Circuit cases to take an element containing “means” out of § 112 ¶ 6:
- “Perforation means extending from the leg band means to the waist band means through the outer impermeable layer means for tearing the outer impermeable layer means.” Cole v. Kimberly-Clark Corp., 102 F.3d 524 (Fed. Cir. 1996). The structure here was presumably the word “perforation,” and perhaps the requirement that it extend from the leg bad means to the waist band means through the outer impenetrable layer means.
- “[T]he ‘gearbox means for rotating said blade means’ of claim 15 is further defined in the claim to comprise ‘a pair of rotatable shafts projecting downwardly from said frame means and defining a biaxial plane.’ Similarly, the ‘flexible drive shaft means for actuating said gearbox means’ is defined by claim 15 itself to comprise ‘individual shaft sections axially linked together by friction disk means for facilitating bending.’ Such detailed recitation of structure clearly removes these limitations from the ambit of § 112, paragraph 6.” Allen Eng’g Corp. v. Bartell Indus., 299 F.3d 1336 (Fed. Cir. 2002).
The following are some examples of structure found insufficient to take an element containing “means” out of § 112 ¶ 6:
- “[D]etent means . . . for moving and maintaining [the] movable member.” Interspiro USA Inc. v. Figgie Int’l Inc., 18 F.3d 927, 930-31 (Fed. Cir. 1991).
- “[S]pring means tending to keep the door closed.” Unidynamics Corp. v. Automatic Prods. Int’l, Ltd., 157 F.3d 1311 (Fed. Cir. 1998).
As far as these cases suggest, the unanimous panel’s holding in Lighting Ballast as to “voltage source means” can be said to fall in a gray area, and does not appear obviously inconsistent with precedent. Perhaps that is why the en banc question is formulated, not in terms of whether the panel was wrong, but in terms of whether it should have deferred to the district court.
A curiosity of the Lighting Ballast case, if one reads the vacated panel opinion, is that the district court changed its mind: at first it had held that the “voltage source means” was subject to § 112 ¶ 6, and then the court held that it wasn’t. A potential implication is that the decision may be one on which reasonable minds may differ; query whether that suggests that this determination should be entitled to some deference when considered afresh on the appellate record.
“Aspects” Of Claim Construction That Might “Be Afforded Deference”
We will next consider some suggestions as regards question c posed by the Federal Circuit: namely, if deference becomes the rule of the Federal Circuit, then “which aspects [of the claim construction] should be afforded deference?” It is noted that the United States, weighing in as amicus in favor of overruling Cybor, nevertheless argues that there should be limits on the parts of claim construction to which the Court of Appeals should defer: for example, the United States argues, “constructions based entirely on the patent document itself should be reviewed de novo,” but “[f]indings of historical fact” should be entitled to deference.
Claim construction is a complex process as to which there is an enormous amount of caselaw. At a guess, perhaps half of all the precedential opinions of the Federal Circuit involve claim construction. Underlying claim construction there is a vast number of issues that could be called factual, and so in the American mindset would be candidates for some sort of deference.
It is not appropriate here, fascinating thought it might seem, to discuss in comparative perspective the American concept of deference. Likewise, we will not discuss the many varieties of deference in American law, except to note that the deference owed by an appellate court to a decision made by a district judge is generally governed by Federal Rule of Civil Procedure 52, which calls it review for “clear error.”
One potential way to approach the issues underlying claim construction is to divide these issues broadly into two classes. The first is the meaning of words, and the second is everything else.
The meaning of words has been and remains controversial. To begin with there is the ordinary meaning of claim terms to those of skill in the art at the time of the invention. “The words of a claim are generally given their ordinary and customary meaning as understood by a person of ordinary skill in the art when read in the context of the specification and prosecution history.” Thorner v. Sony Computer Entertainment, Inc., 669 F.3d 1362, 1365 (Fed. Cir. 2012). This legal rule is unchanged, at least in the language in which it has been stated, since Markman v. Westview Instruments Inc., 52 F.3d 967, 986 (Fed. Cir. 1995) (en banc), aff’d, 517 U.S. 370 (1996), where we read: “the focus in construing disputed terms in claim language is not the subjective intent of the parties to the patent contract when they used a particular term. Rather the focus is on the objective test of what one of ordinary skill in the art at the time of the invention would have understood the term to mean.” To at least some observers, this focus on ordinary meaning suggests the pertinence of objective sources, for example dictionaries and surveys of the usage of words among those of skill in the art (the raw material out of which dictionaries are constructed). Surely the meaning of a technical term in a particular time is a factual matter.
In reality, however, it may be that the meaning of words to those of skill in the art is among the aspects of claim construction least likely to be reviewed deferentially. In other caselaw, despite the references to ordinary meaning cited above, we read: “‘Usually, [the specification] is dispositive; it is the single best guide to the meaning of a disputed term.’” Phillips v. AWH Corp., 415 F.3d 1303, 1315 (Fed. Cir. 2005) (en banc) (quoting Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). Remember too that in the quote from Thorner given above, it is the meaning for the person of skill in the art in the context of specification and file wrapper which matters. The meaning of a claim term may thus, at least arguably, be seen as a possible tug of war in which the specification and file wrapper may tug one way and the actual usage of those of skill in the art may tug in a very different way, or in multiple ways, since words can be used with different meanings. In cases too numerous to list, the specification has won that tug of war. The power of the Federal Circuit to decide the outcome of that tug of war is one that it seems unlikely to renounce.
Questions of word meaning do not always arise, we should add, in the pure form in which a word appears in the claims and is being disputed by the parties. A word can instead appear in a claim construction adopted by the district judge and can then be further construed. See, e.g., Cordis Corp. v. Boston Scientific Co., 658 F.3d 1347 (Fed. Cir. 2011) (“Cordis does not challenge the district court’s construction of the term ‘undulating’ as requiring ‘at least a crest and a trough.’ We therefore do not review the construction itself, and instead focus on what that construction means. Based on the ordinary meaning of the construction as given to the jury, it is apparent that the construction requires multiple ‘waves.’”). A word can appear in a file wrapper (or in a prior art reference cited in the file wrapper), and a dispute can arise as to what it is saying, and also as to whether that statement is clear enough, since there is a clear statement rule for interpreting statements in the file wrapper. Perhaps in disputes of that kind, rather than disputes as to the final meaning of words in the claim, there is room for deference.
Let us now look at some more arguably factual issues which arise in claim construction, other than the meaning of words to those of skill in the art:
a) It is common to argue that a claim should be read to encompass particular disclosed embodiments. For example, we read in Dow Chemical Co. v. Sumitomo Chemical Co., 257 F.3d 1364, 1378 (Fed. Cir. 2001), that “a claim construction that excludes a preferred embodiment is rarely, if ever, correct.” It would seem often to be a factual issue whether the preferred embodiment or some or all disclosed embodiments inherently possess a certain property, so that the claims should not be interpreted to exclude products or processes possessing that property. For example, a chemical claim may say “substantially pure,” and an example may recite a synthesis pathway; numerous cases suggest that if the product that results from that pathway has, for example, 10% impurities, then “substantially pure” might be interpreted to encompass at least 10% impurities.
b) Whether the structure recited in a means plus function claim element is sufficient to perform the recited function, so that the element is not in fact subject to § 112 ¶ 6. This inquiry has been pursued at least as far back as Rodime PLC v. Seagate Technology, Inc., 174 F.3d 1294, 1302-03 (Fed. Cir. 1999), and of course more recently in Lighting Ballast itself.
c) What structure in the specification corresponds to a particular means plus function claim element. “[A] determination of corresponding structure is a determination of the meaning of the ‘means’ term in the claim and is thus also a matter of claim construction.” Chiuminatta Concrete Concepts, Inc. v. Cardinal Indus., Inc., 145 F.3d 1303, 1308 (Fed. Cir. 1998). The judge does this, a most ungrateful task with typical patent specifications, which are written in technical language by a patent attorney whose technical education may be decades in the past. Alternatively, the determination of such structure may be seen as a matter of interpretation of language and thus legal but not factual, but certain subissues may still be seen as factual, as for example the requirement set out here: “The corresponding structure to a function set forth in a means-plus-function limitation must actually perform the recited function, not merely enable the pertinent structure to operate as intended . . . .” Asyst Technologies, Inc. v. Empak, Inc., 268 F.3d 1364, 1371 (Fed. Cir. 2001). The panel in Asyst gave an example: “An electrical outlet enables a toaster to work, but the outlet is not for that reason considered part of the toaster.” Id.
d) Whether construing claims in a particular way would render them invalid. It is a canon occasionally invoked that claims should not be construed in a way that makes them invalid. See, e.g., Wang Labs., Inc. v. America Online, Inc., 197 F.3d 1377, 1382 (Fed. Cir. 1999) (ascertaining whether claims as broadly interpreted would be enabled). Invalidity has many factual subissues, for example for obviousness the Graham factors, or the existence of a motivation to combine references.
e) Whether patents in a similar field of technology use a word in a sense narrower than that which the U.S. Patent and Trademark Office is attributing to them in the patent-at-issue, a phenomenon said, in In re Cortright, 165 F.3d 1353, 1358 (Fed. Cir. 1999), to potentially demonstrate that a claim construction in the USPTO is unreasonably broad.
A Final Word On “Indefiniteness”
Finally, it should be mentioned that indefiniteness, like claim construction, is currently reviewed without deference, i.e., de novo. A change in the application of deference to claim construction may lead to such a change also in the determination of indefiniteness – after all, indefiniteness is found “only if reasonable efforts at claim construction prove futile.” Exxon Research & Eng’g Co. v. United States, 265 F.3d 1371, 1375 (Fed. Cir. 2001).
The Federal Circuit has scheduled oral argument in its rehearing en banc of Lighting Ballast for September 13, 2013. It will be interesting to see what, if any, adjustments are made to Cybor’s rule.
Kenneth J. Weatherwax and Flavio M. Rose, Goldberg Lowenstein & Weatherwax LLP.