by Dennis Crouch
Inter partes review have been shown to be a powerful mechanism for challenging and ultimately cancelling questionable patents. The process was designed by Congress to be somewhat streamlined and thus has a strict limitation that IPR trials only focus on novelty/obviousness and, those challenges must be based only on “prior art consisting of patents or printed publications.” 35 U.S.C. § 311(b).
In ordinary patent law, a prior art printed publication consists of some document that was published before the “critical date” of the patent application. Although Section 102 was reorganized somewhat by the America Invents Act, this principle still rings true today as it has for the past 150+ years.
But, here is where it gets weird: in Lynk Labs, the Federal Circuit concluded that for the purposes of 311(b), a “prior art … printed publication” includes documents that were published well after the challenged-patent’s filings date. Treating these as two separate requirements, the court found that a reference could be used so long as it (1) qualified as prior art; and (2) was ultimately published at some point.
Now, Lynk Labs has petitioned the Supreme Court for a writ of certiorari asking:
Whether patent applications that became publicly accessible only after the challenged patent’s critical date are “prior art * * * printed publications” within the meaning of 35 U.S.C. § 311(b).
Lynk Labs, Inc. v. Samsung Electronics Co., Ltd., No. 25-308 (petition filed Sept. 2025).
Prior posts:
- Dennis Crouch, Secret Springing Prior Art and Inter Partes Review, Patently-O (Oct. 15, 2024), https://patentlyo.com/patent/2024/10/secret-springing-partes.html.
- Dennis Crouch, Publications Before Publishing and the Federal Circuit’s Temporal Gymnastics, Patently-O (Jan. 15, 2025), https://patentlyo.com/patent/2025/01/publications-publishing-gymnastics.html.
- Dennis Crouch, Prior Art Document vs. Prior Art Process: How Lynk Labs Exposes a Fundamental Ambiguity in Patent Law, Patently-O (July 9, 2025), https://patentlyo.com/patent/2025/07/document-fundamental-ambiguity.html.
The case centers on what I think of as secret springing prior art that is defined now under 35 U.S.C. 102(a)(2) (pre-AIA 102(e)) that came about once the USPTO began publishing patent applications about 25 years ago. Under the statute, a published patent application is not simply treated as an ordinary printed publication. Rather, Congress created a special rule that makes published patent applications prior art as of their filing date, not their publication date. This creates a peculiar temporal anomaly: an application filed in secret can later “spring” into being prior art against patents filed after the application but before the application’s publication.
At the time the later patent was filed, the earlier application was confidential and unknown to the public—yet once that earlier application eventually publishes (typically 18 months after filing), it suddenly becomes prior art backdated to its original filing date. In Lynk Labs, the Federal Circuit concluded that this 102(a)(2) prior art qualifies for IPR usage as a printed publication.
Ultimately, in its decision, the Federal Circuit concluded that the term “printed publication” is “temporally agnostic.” Under the Federal Circuit’s bifurcated analysis, courts must ask two separate questions: (1) whether a reference qualifies as a “printed publication” based solely on whether it ever became publicly accessible, and (2) whether that publication constitutes “prior art” under any applicable statutory provision. For the Martin patent application in Lynk Labs, the court found it satisfied the first test because it was eventually published, and satisfied the second test by applying the special timing rule for patent applications under 35 U.S.C. § 102(e)(1), which makes published applications prior art as of their filing date.
This approach allowed Samsung to use an abandoned (but published) patent application that was filed before Lynk’s priority date but published months later. The Martin application was confidential and inaccessible to the public when Lynk filed its LED lighting patent application in February 2004, yet became “prior art” when it published in October 2004, retroactively applying from its April 2003 filing date.
I’ll have more on this important case in the upcoming weeks.
The EP way is simple and likely better than the conflict and confusion. The spring art can be novelty destroying but not inventive step destroying. It’s a balance, and it at least pins the inventive step / obviousness argument to what a person of ordinary skill in the art understood at the time of filing as the application wasn’t published and known to the skilled person.
Yes, but the EPO “only novelty prior art until published” route has other problems. Especially, given the number of patents by different inventors often filed within a relatvely short time period of one another on major new technologies [e.g., CRISPER]. It can lead to plural conflicting blocking patents with relatvely trivial claim differences – a licensing, and necessary cross-licensing, mess.
Besides the nearly hopeless odds of challenging the extremely long standing U.S. statutory and case law principle that a patent is prior against others as of its filing date, there would be weird and unsettling commercial consequences for both patent owners and product producers if it was overruled. Nor is their any legal or logical bases for dfferent patent 102 or 103 law in an IPR versus in the courts. In any case, the several novel sua sponte rule changes the current PTO Assistant Director is using to block the vast majority of IPRs [documented in a draft article I hope to see published] should render IPR cases like this moot.