Federal Circuit Affirms PTAB’s Admission of Late Evidence on Public Accessibility of Prior Art

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On Thursday of last week in Telefonaktiebolaget LM Ericsson v. TCL Corporation, the Federal Circuit affirmed two Patent Trial and Appeal Board (PTAB) decisions (IPR2015-01584 and IPR2015-01600) finding that a single claim in an Ericsson patent was invalid as obvious as over a German article that was submitted late in the game. While there is nothing groundbreaking or unusual in the court’s affirmation of the PTAB’s obviousness finding, the opinion highlights the liberal admissibility standard for supplemental or “late” evidence at the PTAB and outlines what may be required to establish when an article published in a periodical or journal becomes publicly accessible. 

The patent at issue (U.S. Patent No. 6,029,052) related to a direct conversion receiver for wireless communication systems that may receive signals from systems that operate at different frequency bands. As detailed in the ʼ052 patent, the claimed method was an improvement over conventional solutions of receiving and processing wireless signals from communication systems operating at different frequencies such that in the claimed method, receivers can receive signals at multiple frequency bands without requiring significant hardware duplication. TCL filed the two IPRs in 2015 after Ericsson attempted to add a claim for patent infringement of the ʼ052 patent to a suit originally filed in the Central District of California in 2014. While TCL originally challenged four claims of the ʼ052 patent in both IPRs (consolidated by the PTAB) and the PTAB found that all four claims were invalid as obvious, Ericsson only appealed the PTAB’s finding with respect to one dependent claim (claim 18). 

Because the German article was the primary reference used to invalidate claim 18, the initial issue considered by the court was whether the German article was available as prior art to the claim. Both sides agreed that the German article in question was included in the May/June 1996 issue of the journal Ingenieur der Kommunikations-technik. However, the parties disagreed as to when that journal issue was publicly available. According to Ericsson, the May/June 1996 issue of the journal was not publicly available until October 1996, which was after the July 1, 1997 filing date of the application for the ʼ052 patent. TCL, over Ericsson’s objections, was later allowed to introduce evidence (via a declaration from a librarian at the Technische Universität Darmstadt in Germany) that the May/June 1996 issue (including the relevant German article) was in German university libraries as early as June 19, 1996.  The PTAB then found that the librarian’s declaration established that the German article was received by the Darmstadt library in June 1996 and was available to the public as of that time. 

Ericsson tried to convince the Federal Circuit that the PTAB improperly allowed TCL to submit late evidence to establish the publication date of the German article. However, not surprisingly, the court found that the PTAB did not abuse its discretion in admitting the librarian’s declaration, even if tardy, since 1) the evidence is reasonably viewed as material, 2) Ericsson had the opportunity to substantively respond, and 3) the interest of justice weighs on the side of admitting the evidence. Indeed, the PTAB had given Ericsson the opportunity to depose the librarian declarant and to respond to the substance of the German journal article.

The court then considered whether the librarian’s declaration demonstrated that the German article was publicly accessible before the filing date of the ʼ052 patent. In doing so, the court walked through the librarian’s declaration and found that it established that 1) the journal was in the collection of the Darmstadt library since 1963, 2) the librarian declarant had personal knowledge of the library’s inventory and processing practices, as she had worked at the Darmstadt library in 1996 and was still an employee there, and 3) library records show that the May/June 1996 issue of the journal was inventoried on June 18, 1996, and made available to the public one to two days later. The court further explained that the facts here differed from prior cases when a single dissertation or thesis was housed in a library but not deemed publicly accessible because such dissertation or thesis was not catalogued or indexed in a meaningful way. Here, there was no dispute that the journal itself had been published for at least 30 years before the May/June 1996 issue of the journal was released. Moreover, there was no question that the Darmstadt library was publicly accessible. Furthermore, the librarian’s declaration established that the May/June 1996 issue was catalogued in a meaningful way. The court also remarked that, while Ericsson did not bear the ultimate burden of proof on whether the German article was publicly accessible, it failed to provide any evidence to rebut the librarian’s declaration, the date on the face of the journal, and the library’s records showing receipt of the journal. Ultimately, the court held that substantial evidence supported the PTAB’s finding that the German article was publicly accessible in the May/June 1996 time period and, thus, available as prior art to the claims of the ʼ052 patent.

With the first issue on appeal put to rest, the Federal Circuit quickly dismissed Ericsson’s attempts to save claim 18 of the ʼ052 patent from invalidity. As to Ericsson’s contention that the German article was merely a feasibility study and not enabled, the court did little more than recite the PTAB’s findings. As to Ericsson’s argument that the prior art teaches away the claimed method as a preferred solution, the court explained that for a reference to teach away, a person of ordinary skill in the art would have had to have been discouraged from following the path set out in the reference or would have been led in a different direction than the claimed method. While the German article did discuss the disadvantages of the claimed method, the court noted that the reference did not suggest that the method would be ineffective in achieving the objective. In other words, since the German article did not “criticize, discredit, or discourage the technological efficacy” of the claimed method, it did not teach away as contended by Ericsson. With that, the court concluded that substantial evidence supports the PTAB’s findings and conclusions and the invalidity of claim 18 of the ʼ052 patent was affirmed.

So, what are the key takeaways from the decision? First, under the applicable PTAB rules, while submission of supplemental or “late” evidence (i.e., evidence more than one month after institution) must be authorized by the PTAB, the PTAB rarely denies such a motion provided that it explains why the supplemental evidence could not have been obtained earlier and why its consideration would be in the interests of justice.  The Federal Circuit will not find such action by the PTAB an abuse of discretion as long as the evidence is reasonably viewed as material and the opponent has adequate opportunity to respond and produce contrary evidence. Second, despite the liberal admissibility of late evidence at the PTAB, it is a best practice to include in the IPR petition a declaration or other evidence that demonstrates how and when non-patent literature, such as an article published in a periodical or journal, became publicly available. Third, despite the lack of success on appeal by Ericsson in this case, PTAB practitioners should still object to evidence that seems unfair to consider to preserve the issue for appeal.