Guest post by Donald S. Chisum, Chisum Patent Academy
Looking back at the approximately 125 precedential decisions on patent law of the Federal Circuit in 2012, I asked myself: are there any new trends? One trend smiled back: an increase in the number of decisions on the doctrine of equivalents. There were eight, and, surprisingly, four of them showed judicial favor toward application of the doctrine.
Since 1997, the Federal Circuit, with the encouragement of the Supreme Court, has developed various restrictions and limitations on the doctrine. This has led some commentators to assert that the doctrine of equivalent is "dead." See Allison & Lemley, The (Unnoticed) Demise of the Doctrine of Equivalents, 59 Stan. L. Rev. 955 (2006-2007). That obituary may have been premature. The Supreme Court created the doctrine in 1850 and twice rejected frontal assaults: in 1950 and 1997. The 2012 Federal Circuit decisions show that well supported assertions of equivalency cannot be dismissed.
In particular, Chief Judge Rader wrote two opinions, expanding beyond what was necessary to decide the cases before him. In one, he emphasized that "the Supreme Court declined to let numerous contentions bury the doctrine." Deere & Co. v. Bush Hog (Dec. 4, 2012). In Deere, Judge Rader attempted to clarify "misperceptions" about the "vitiation" limitation on the doctrine of equivalents. For a comment on Judge Rader's discussion of vitiation, see Dennis Crouch, Reviving the Doctrine of Equivalents, Patently-O at http://www.patentlyo.com/patent/2012/12/rader-reviving-the-doctrine-of-equivalents.html.
In the other case, Judge Rader stressed that the doctrine is particularly appropriate when an accused equivalent is made possible only by technological improvements after a patent's effective filing date. Energy Transportation Group v. William Demand Holdings (Oct. 12, 2012). Judge Rader has long espoused the view that the doctrine should be available when equivalents are not foreseeable but not when the opposite was true. A competent draftsperson should write claims to cover literally equivalents that were foreseeable at the time the application for the patent was prosecuted.
Also significant were two opinions by other judges. In one, the court addressed the recurring issues of equivalency applied to numerical and range limitations and to qualifiers such as "substantially." Pozen Inc. v. Par Pharmaceutical (Sept. 28, 2012). The majority, by the recently-appointed Federal Circuit Judge Wallach, held that a claim, which required that a drug tablet layer have "substantially all" of an ingredient, and which was construed to mean "at least 90%," was properly found infringed by equivalency by an accused tablet that had only 85% of the ingredient in the layer.
In another case, the court, in an opinion by Judge Prost, held that a district court erred in applying the "disclosure-dedication" rule and thus erred in granting summary judgment of no infringement under the doctrine of equivalents. Sandisk Corp. v. Kingston Technology Co., Inc. (Oct. 9, 2012).
In the other four cases, the Federal Circuit concluded, essentially, that asserted equivalents were not sufficiently equivalent or involved completely missing claim limitations or failure to claim literally well-known interchangeable elements. Technology Patents LLC v. T-Mobile Ltd. (Oct. 17, 2012); Mirror Worlds, LLC v. Apple Inc. (Sept. 4, 2012); General Electric Co. v. U.S. Int'l Trade Comm'n (July 6, 2012); Wm. Wrigley Jr. Co. v. Cadbury Adams USA LLC (June 22, 2012).
One may ask: why would there be renewed judicial interest in the doctrine of equivalents? One possibility: developments in other areas of patent law, such as the "abstract idea" restriction on Section 101 patent eligible subject matter, are creating pressures on patent applicants to formulate claims that are specific and narrow in literal scope. Courts may use a more robust doctrine of equivalents to provide a scope of protection that is determined to be appropriate in view of the patent's disclosure, the prior art, and the development of the pertinent technology after a patent's effective filing date.