Prosecution Laches

  • Prosecution Laches Is An Equitable Defense That Arises From Unreasonable Delay In Prosecution: Prosecution laches is an equitable defense that may bar enforcement of a patent that issued after an unreasonable and unexplained delay in prosecution caused by the patentee. Symbol Techs. (Fed. Cir. 09/09/05) (see order amending opinion). “An applicant must therefore not only comply with the statutory requirements and PTO regulations but must also prosecute its applications in an equitable way that avoids unreasonable, unexplained delay that prejudices others.” Hyatt (Fed. Cir. 06/01/21) (vacating in a 145 action trial court’s Summ. J. against USPTO of no prosecution laches where applicant filed 381 placeholder applications at GATT bubble, later expanded number of claims to 115,000, delayed between 12 to 28 years (based on asserted priority dates) to present his claims for prosecution, and “adopted an approach to prosecution that all but guaranteed indefinite prosecution delay”; explaining history of defense). Supreme Court has found patents unenforceable based on 8- and 9½-year prosecution delays. Woodbridge (U.S. 11/12/1923) (9 ½ years); Webster (U.S. 04/07/1924) (8 years).
  • Prosecution Laches Considers Totality Of The Circumstances Including Prosecution Of Related Patents: Laches finding may be based on “an examination of the totality of the circumstances, including the prosecution history of all of a series of related patents and overall delay in issuing claims, may trigger laches.” Hyatt (Fed. Cir. 06/01/21) (faulting trial judge for disregarding swaths of such evidence, and for its overemphasis on actions of USPTO).
  • Prosecution Laches Requires Intervening Rights Of Defendant Or Public, But Unexplained Six-Year Delay May Create Presumption Of Intervening Rights: D. Ct. found prosecution laches based on “eleven continuation applications [initial app. filed in 1982], ten abandonments, and no substantive prosecution for nearly a decade,” after initial rejection for lack of utility. Fed. Cir. rev’d. “[A]n accused infringer must show evidence of intervening rights, i.e., that either the accused infringer or others invested in, worked on, or used the claimed technology during the period of delay.” Cancer Research (Fed. Cir. 11/09/10) (not discussing whether delay more than six years creates presumption; 5 of 10 Fed. Cir. judges would have granted rehearing en banc to rule that intervening rights is not required: Cancer Research (Fed. Cir. 02/28/11)). Cf. Hyatt (Fed. Cir. 06/01/21) (in 145 action, “the PTO must generally prove intervening rights to establish prejudice, but an unreasonable and unexplained prosecution delay of six years or more raises a presumption of prejudice, including intervening rights,” and “where a patent applicant has committed a clear abuse of the PTO’s patent examination system, the applicant’s abuse and its effects meet the prejudice requirement of prosecution laches. A clear abuse of the patent system occurs when, for example, the applicant’s conduct unduly increases the administrative burden on the PTO and thereby effectively taxes everyone using the system.”).

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