Chapter §19.01 Introduction

• Jurisdiction: United States

§19.01 Introduction

When sued for patent infringement an accused infringer will almost always assert the following two defenses: (1) that its product/process does not infringe; and (2) that even if its product/process does infringe, the asserted patent is invalid, so the accused infringer is not liable for infringement. In many cases, the accused infringer will add a third defense, namely, that the court should refuse to enforce the asserted patent because it was procured from the USPTO through inequitable conduct.¹ These defenses may also be asserted as counterclaims or raised affirmatively by a plaintiff seeking a declaratory judgment of non-infringement, invalidity, and/or unenforceability.²

The statutory basis for asserting these and other defensive theories is paragraph (b) of 35 U.S.C. §282, which provides that the following defenses can be pleaded in a lawsuit concerning the validity or infringement of a U.S. patent:

(1) Noninfringement, absence of liability for infringement or unenforceability.

(2) Invalidity of the patent or any claim in suit on any ground specified in part II [35 U.S.C. §§100 et seq.] as a condition for patentability.

(3) Invalidity of the patent or any claim in suit for failure to comply with—

(A) any requirement of section 112 ["Specification"], except that the failure to disclose the best mode shall not be a basis on which any claim of a patent may be canceled or held invalid or otherwise unenforceable; or

(B) any requirement of section 251 ["Reissue of Defective Patents"].

(4) Any other fact or act made a defense by this title. ³

Several of the defenses enumerated in §282(b) are more accurately understood as categories that encompass a variety of defensive theories.⁴ For example, the defense of "unenforceability" referred to in 35 U.S.C. §282(b)(1) can be established on the basis of inequitable conduct, patent misuse, or prosecution laches. The defense of invalidity referred to in 35 U.S.C. §§282(b)(2)-(b)(3) can be based on a failure of the patent to comply with the requirements of utility, novelty, nonobviousness, enablement, and the like.

Each defense encompassed within §282(b) is analyzed separately below.

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Notes:

^[1] A study prepared in the late 1980s estimated that 80 percent of U.S. patent infringement lawsuits included an allegation of inequitable conduct. See Therasense, Inc. v. Becton, Dickinson and Co., 649 F.3d 1276, 1289 (Fed. Cir. 2011) (en banc) (citing Committee Position Paper, The Doctrine of...