Prosecution History Laches

  • Prosecution Laches 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).
  • Prosecution Laches Requires Intervening Rights Of Defendant Or Public: 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) (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)).

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