The CAFC confirms that the PTAB concluded that the prior art reference was not “by another”

“[T]The content of the Tsang patent that went beyond the disclosure of Seagate’s annual report was not relevant to the advance challenge of claims 14 and 17 of the ‘601 patent.

In a landmark ruling issued earlier this month, the United States Court of Appeals for the Federal Circuit (CAFC) affirmed a decision of the Patent Trial and Appeal Board (PTAB) in an appeal by LSI Corporation and Avago Technologies US Inc. (LSI) regarding the PTAB’s finding that the reference cited by LSI in an international examination partes (DPI) was not considered prior art. The CAFC declared in part that U.S. Patent No. 5,731,768 (“Tsang”) was not “by another” under 35 USC 102(e) for US Patent No. 5,859,601 (‘601 patent).

The ‘601 patent involves receiving sequences of input data blocks that contain error-prone patterns, then converting each input data block into a corresponding “code word” that bypasses the error-prone pattern. The ‘601 patent works to convert blocks of input data into codewords that (1) “impose a limit on the maximum number of consecutive transitions” that are written to the storage device and (2) impose a limit on the number maximum of non-transitions. These two limitations on bit transitions are incorporated into the claims with the ‘j’ constraint and the ‘k’ constraint. Claim 13 serves as the most general claim with these constraints while claim 14 restricts the limitations and claim 17 further restricts claim 14.

LSI argued that claim 14 of the ‘601 patent is anticipated by US Patent No. 5,392,270 (okada) and US Patent No. 5,731,768 (Tsang). Okada describes converting input data blocks using two rules that suppress the event of certain patterns in input data blocks for optical discs. Okada includes Tables 1 through 9 which include an example mapping of all 8-bit input data blocks to converted 13-bit output data blocks. LSI initially argued that Okada’s disclosure of its second rule anticipated claims 14 and 17, but later argued that Tables 8 and 9 were embodiments that anticipated claims 14 and 17.

LSI’s second theory held that Tsang anticipated the ‘601 patent and, more specifically, the portions of Tsang disclosed in what is known as Seagate’s annual report. Some context regarding the ‘601 patent is necessary to understand Tsang’s anticipatory argument. In September 1995, the inventors of the ‘601 patent submitted Seagate’s annual report on their coding to Seagate. Material found in Seagate’s annual report was later incorporated into the ‘601 patent.

In the ‘601 patent and Seagate’s annual report, the encoding process takes an input sequence of binary data and encodes it in such a way as to remove error-prone patterns from consecutive bit transitions before storing the encoded sequence in a computer storage device. There has been no assertion that Seagate’s Annual Report can be relied upon as prior art for the ‘601 patent, but since the inventors of the ‘601 patent are the sole authors of Seagate’s Annual Report, it cannot not be considered “by another” under Section 102 even if it was publicly available before the priority date.

LSI instead relied on another available prior art patent, Tsang, to anticipate claims 14 and 17 of the ‘601 patent. About four months after receiving Seagate’s annual report, but before the ‘601 patent was filed, Dr. Kinhing Tsang, a Seagate employee, filed a patent application that would later become the Tsang patent. There was no common invention between the ‘601 patent and Tsang. Tsang revised the encoding process described in Seagate’s annual report, which resulted in a higher I/O rate allowing for more efficient storage.

History of the procedure

In August 2016, the University of Minnesota (UMN) Regents filed suit against LSI for infringement of the ‘601 patent. LSI then filed an IPR application for the ‘601 patent. Before the PTAB, UMN requested that LSI’s motion be dismissed on the grounds of sovereign immunity. The PTAB rejected this request but suspended the proceedings while the UMN appealed the PTAB’s decision.

In the ensuing proceeding, the UMN rejected all of the disputed claims except for claims 13, 14 and 17. The PTAB issued its final decision in April 2021, finding that claim 13 was anticipated by Okada. However, the PTAB found that LSI had failed to demonstrate that claims 14 and 17 were unpatentable to Okada or Tsang.

The PTAB determined that LSI’s argument that Okada’s tables anticipate claims 14 and 17 was misplaced because they were not raised on appeal. Also, while the arguments were presented in a timely manner, LSI has still not explained how the tables independently comprised the complete embodiment. Regarding Tsang’s motives, the PTAB found that LSI “has failed to meet its burden of proving that the parts of Tsang relied upon for anticipation represent the work of another to qualify as prior art in under Section 102(e)”.

Okada’s prior art

The CAFC began its analysis by examining whether the PTAB erred with respect to Okada. LSI argued on appeal that it did not need to challenge the decision to miss the deadlines because the PTAB had ruled on the merits. Citing Intelligent Bio-Systems, Inc. v. Illumina Cambridge Ltd. (CAFC, 2016), where the court rejected a similar claim, the CAFC upheld the PTAB’s delay finding because LSI waived any challenge to the delay decision after failing to challenge it in its opening brief on appeal and that the decision of the PTAB constitutes an independent decision. reason for its decision.

Tsang Prior Art

The court then considered whether the PTAB was correct in denying LSI’s claim based on Tsang in determining whether the relevant parts of Tsang described an invention “by another”. Quoting to Duncan Parking Techs., Inc. v. IPS Group, Inc.. (CAFC, 2019), determining whether a reference is “by another” involves three steps. The PTAB must (1) determine which portions of the reference have been relied upon as prior art to anticipate the limitations at issue, (2) assess the extent to which those portions were designed “by another” and (3) decide whether that other person’s contribution is significant enough to make them a co-inventor.

LSI argued that it relied on Tsang to establish the anticipation, thereby responding to the first prong of the Duncan parking lot test and since Tsang is a species of the genus described in the ‘601 patent, Tsang anticipates claims 14 and 17. The CAFC determined that LSI misunderstood this test, because the question is rather whether Tsang’s invention was invoked and relevant for anticipation, or whether it was simply Tsang’s summary of Seagate’s previous annual report that was used and relevant for anticipation. Tsang’s summary and reliance on Seagate’s annual report does not make Tsang an inventor of the ‘601 patent.

The CAFC continued:

“[T]The motion relied on both portions of Tsang that summarized Seagate’s annual report and additional portions of Tsang that were not merely derived from Seagate’s annual report, portions describing Tsang’s specific invention. But these extra portions of Tsang are irrelevant for the anticipation.

Tsang’s unique characteristics were not relevant to the anticipation of claims 14 and 17, and the characteristics relevant to the anticipation were disclosed in Seagate’s annual report and merely repeated in the Tsang background section. . The court found that the PTAB did not err in finding that it was satisfied that the petition relied on information disclosed in both Tsang and Seagate’s annual report. The CAFC concluded that the PTAB’s findings that material from the Tsang patent that went beyond the disclosure of Seagate’s annual report was not relevant to the advance challenge of claims 14 and 17 of the ‘601 patent and that the presentation of the report Seagate’s annual at Tsang didn’t make him an inventor of the matter.

Christopher S. Washington