Background
Gilbert Hyatt is a prolific inventor who, beginning in the 1970s and 1980s, filed numerous patent applications related to microprocessors and computing. Through a combination of procedural maneuvers — filing continuation after continuation, amending claims repeatedly, and challenging USPTO rejections in a seemingly endless loop — Hyatt managed to keep hundreds of applications pending for decades. Under pre-GATT patent law, patents had a term of 17 years from issuance rather than 20 years from filing, so an applicant who kept applications pending could effectively extend the patent term by delaying prosecution.
These so-called “submarine patents” surfaced decades later, often surprising industries that had built products assuming the relevant technology was in the public domain. By the early 2000s, Hyatt had collected settlements and license fees from major technology companies on patents that had been pending since the Carter administration. When the USPTO finally refused to allow additional claims, Hyatt filed dozens of civil actions under 35 U.S.C. § 145, which allows an applicant to challenge a USPTO rejection in district court rather than before the PTAB.
The USPTO raised prosecution laches as a defense, arguing that Hyatt’s decades of strategic delay — combined with the prejudice to third parties who had invested in the affected technology fields — barred him from obtaining patents on these long-pending applications. The district court rejected that defense. The Federal Circuit reversed.
The Court’s Holding
The Federal Circuit held, for the first time, that the doctrine of prosecution laches is available to the USPTO as an affirmative defense in a § 145 civil action. Judge Taranto’s opinion reasoned that § 282 of the Patent Act makes affirmative defenses broadly available in patent proceedings, and that prosecution laches is a well-established equitable doctrine that applies when an applicant engages in an unreasonable and unexplained delay that prejudices others.
The court held that a delay of six years or more raises a rebuttable presumption of prejudice to third parties, including those who built businesses on the assumption that the technology was available to the public. It found that Hyatt’s pattern of refiling and amending applications across hundreds of pending cases — often repeating the cycle after a rejection — constituted a clear abuse of the examination system. The court remanded for the district court to properly apply the prosecution laches standard, taking into account the totality of the circumstances across Hyatt’s entire application portfolio rather than analyzing each application in isolation.
Key Takeaways
- Prosecution laches is now a confirmed defense available to the USPTO in § 145 civil actions, allowing the government to block patents where applicants have engaged in unreasonable, prejudicial delays.
- A delay of six or more years in prosecution raises a rebuttable presumption of prejudice to third parties who relied on the technology being in the public domain.
- Courts assess prosecution laches based on the totality of circumstances, including the applicant’s broader filing pattern — not just the history of a single application.
- The decision effectively closes the “submarine patent” loophole for legacy applications: indefinite delay through continuation practice can now be challenged on laches grounds even when the procedural rules were technically followed.
Why It Matters
The Hyatt v. Hirshfeld decision is a significant win for patent system integrity and for industries that have faced submarine patent attacks. For decades, sophisticated applicants exploited the old 17-year-from-issuance patent term to delay prosecution strategically, causing issued patents to surface long after competitors had invested in the relevant technology. While post-GATT law largely closed this window for new applications by switching to a 20-year-from-filing term, legacy applications from the pre-GATT era remained a threat.
By confirming that prosecution laches can block such patents, the Federal Circuit gave the USPTO a meaningful tool to defend the public interest in a patent system that does not reward strategic delay. The decision also signals that applicants who abuse continuation practice — even under current rules — may face laches challenges if their delays are unreasonable and cause prejudice to third parties who built businesses on the assumption that the claimed technology was freely available.