Indefiniteness as an invalidity defense.

Author:Smith, Janet M.

TABLE OF CONTENTS INTRODUCTION I. THE MECHANICS OF PATENT LITIGATION A. Claim Construction B. Assessing Patent Validity 1. Enablement 2. Anticipation 3. Written Description 4. Definiteness II. LESSONS FROM TEVA V. SANDOZ A. Teva on Remand B. Teva's "Good"Patents III. THE FUTURE OF INDEFINITENESS A. Claim Construction Is Not the Problem B. "Consequentially Ambiguous" CONCLUSION INTRODUCTION

Should a good patent be deemed invalid because it is not perfect? (1) Assume the good patent satisfies all the important elements of patentability: it claims novel, (2) nonobvious, (3) and patent-eligible (4) subject matter; sufficiently discloses the claimed invention at the time of application; (5) contains embodiments that enable a skilled artisan to practice the invention; (6) and discloses the best version of the invention. (7) The good patent's only imperfection resides in a slightly imprecise term. (8) But the imprecision does not cause demonstrable confusion about the scope or content of the invention claimed. (9) The perceived defect appears entirely without real-world consequence. (10)

Invalidating such a good patent for inconsequential imperfection seems unadvisable. (11) No deterrence rationale justifies allowing such insubstantial error to be fatal. (12) Nonetheless, in the course of infringement litigation, such a minor defect might lead a court to invalidate the good patent as indefinite. (13)

Providing the statutory hook for definiteness jurisprudence, the law requires a valid patent to contain "one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention." (14) When invoking indefiniteness as an invalidity defense, an accused infringer may escape liability by arguing that the claim language appears ambiguous and by convincing the court to invalidate the patent at issue. (15)

Historically, courts tended to invalidate a patent as indefinite only if a claim term proved insusceptible to construction--meaning the evidence in the record failed to enable the court to discern how a person of ordinary skill in the art (POSA) would interpret the disputed claim language. (16) As claim construction jurisprudence tolerates some imprecision, the good patent would not be felled by indefiniteness that operates to invalidate a patent when claim terms cannot be construed. (17)

The true threat to the good patent arises when alleged infringers invoke indefiniteness as an invalidity defense after a court has carefully construed a given claim term. (18) This iteration of indefiniteness as an invalidity defense proves problematic because--when no longer tethered to claim construction, which places great emphasis on reading the patent from the perspective of POSA--the definiteness assessment may result in the invalidation of a patent on the basis of imprecision that causes no actual confusion. (19)

A recent case reveals the hazards posed by permitting defendants to raise indefiniteness as an invalidity defense following claim construction. In Teva Pharmaceuticals USA, Inc. v. Sandoz, Inc. (Teva V), the Federal Circuit, (20) on remand from the Supreme Court, invalidated a fully functional and generally unambiguous group of related patents because of a small, inconsequential defect. (21) Although the district court did not lend legal significance to the alleged indefiniteness given the absence of practical effect, the Federal Circuit assessed definiteness separate from claim construction, without discrete reference to the consequences of any error discovered. (22) Even after the Supreme Court demanded greater deference to the district court's subsidiary fact-finding related to claim construction in Teva IV, (23) the Federal Circuit found Teva's patents invalid without identifying clear error in the district court's fact-finding. (24)

Such dissonance between the Federal Circuit and district courts is not new. (25) The frequency with which the Federal Circuit reverses district court rulings deviates from the norm. (26) For federal appeals courts generally, the civil case reversal rate ranges from 12 to 15 percent. (27) But the Federal Circuit's reversal rate for patent cases averages around 28 percent. (28) The Federal Circuit most often reverses district courts because of disagreements related to claim construction. (29) In fact, excluding reversals implicating claim construction, the Federal Circuit's patent reversal rate would average only 18 percent. (30) Further, reversals premised on indefiniteness of the sort that was dispositive in Teva V averages almost 40 percent, while claim construction reversals overall hover closer to 30 percent. (31)

High reversal rates in patent cases on appeal have been the aim of much scholarly inquiry. (32) The commentary supplies two main explanations for why the Federal Circuit so often reverses district court patent rulings. (33) Either the Federal Circuit has failed to sufficiently articulate the standards for claim construction such that district courts are unable to abide by those standards, or the Federal Circuit has refused to grant district court rulings the deference that information asymmetry demands. (34) Both factors converge for Federal Circuit reversals premised on definiteness. (35) As currently conceived, the requirement enables the appellate court to reverse the lower court's invalidity assessment without opining as to evident claim construction errors, yielding opinions that display only superficial deference and fail to clarify claim construction jurisprudence. (36)

Unlike the other requirements for patentability, definiteness appears inseparable from claim construction. (37) Either a claim term is not susceptible to construction, and thus the patent is indefinite, or the claim term is susceptible to construction and the patent is definite. (38) And yet, the Supreme Court recently reaffirmed definiteness as a conclusion of law separate from claim construction. (39) By forcing this separation, the law enables the Federal Circuit to find no error in lower court claim construction while simultaneously invalidating a patent as indefinite if the claim lacks "reasonable certainty"--a phrase coined by the Supreme Court in 2014 that continues to beg for content. (40) In the context of invalidating a patent as indefinite when competing interpretations prevent the court from construing disputed claim language, "reasonable certainty" may provide sufficient guidance. (41) But "reasonable certainty" provides little guidance as to how the ambiguity of claim language should be assessed after claim construction. (42)

Through a close examination of Teva, this Note argues that the definiteness requirement should rarely be deployed to invalidate a patent for ambiguity following claim construction. (43) If ambiguity remains, then the court failed to properly construe the disputed language. (44) To support this conclusion, Part I overviews the role of invalidity defenses in patent litigation to show how claim construction appears distinct from a court's evaluation of enablement, anticipation, and written description, but remains identical with an assessment of definiteness. Part II closely examines Teva V on remand from the Supreme Court to reveal the extent to which the problematic aspects of definiteness jurisprudence cannot be ameliorated by heightened deference for lower court subsidiary fact-finding. Part III discusses the lessons learned from Teva to propose a new test for definiteness where "consequentially ambiguous" would replace "reasonable certainty" as the phrase that pays in order to provide a more robust link between definiteness and claim construction.


    United States law prohibits the unauthorized making, using, or selling of any "patented invention." (45) The strategies invoked during litigation revolve around what constitutes a "patented invention." (46) An alleged infringer will succeed if she persuades the court that her activities do not fall within the limited number of activities protected by the patents at issue. (47) Alternately, an alleged infringer will succeed if she is able to convince the court that the patent is entirely invalid and thus incapable of precluding her ostensibly infringing activity. (48) Typically, alleged infringers raise both defenses-asserting that the infringing product or process is not identical to the invention claimed in the patent and asserting that, regardless of the subject matter covered by the claims, the patent cannot protect any invention because the patent itself proves deficient. (49)

    One of the first steps in any patent litigation involves the patent owner and the defendant jointly submitting a list of challenged claim terms with each side presenting competing interpretations of each term. (50) The patent owner's interpretation of the claim terms must be broad enough to support the argument that the allegedly infringing product or process falls within the scope of the claimed invention. (51) The defendant interprets claim terms more narrowly to argue that the patent does not cover the infringing product or process. (52) The persuasiveness of the defendant's invalidity arguments hinges on which interpretation prevails. (53)

    Demonstrating the delicate dance of patent litigation, a patent owner's interpretation of a disputed claim term may increase the likelihood that the patent will be invalidated. (54) If the court construes the patent as covering a broad range of activities, then that construction may strengthen the defendant's assertions of anticipation, nonenablement, insufficient written description, or indefiniteness. (55) Accordingly, before the court may assess patent validity, the court must determine how to interpret disputed claim terms--the process known as "claim construction." (56)

    1. Claim Construction

      Patents contain two parts: the specification, followed by individual claims. (57) The...

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