Federal Circuit Holds Word Metadata Can Corroborate an Inventor's Conception Date, Affirming Valtrus's PTAB Win Over Google.

The appeal

The case is Google LLC v. Valtrus Innovations Ltd., No. 2024-1945 (Fed. Cir. Oct. 19, 2026) (precedential), an appeal from the Board's final written decision in IPR2022-01545. Google petitioned for inter partes review of claims 1-23 of U.S. Patent 6,728,704, which the opinion says Valtrus owns. All four of Google's obviousness grounds relied on U.S. Patent 6,711,569 (Bushee), combined with U.S. Patent 5,864,846 (Voorhees) and, in some grounds, U.S. Patent 7,257,766 (Koppel) or U.S. Patent 6,385,602 (Tso). Bushee was filed July 24, 2001, about five weeks before the '704 application was filed on August 27, 2001. Valtrus argued that its inventors conceived the claimed invention before Bushee's filing date and were diligent until filing, so that Bushee is not prior art under pre-AIA 35 U.S.C. 102(e). The Board agreed and held that Google had not shown any claim unpatentable.

What claim 1 recites

The opinion describes the '704 patent as claiming methods and computer-readable memory for merging search-result lists from multiple search engines. Claim 1, as set out in the opinion (slip op. at 2-3), is a method that transmits a query to a set of search engines, receives a result list from each one, selects a subset of entries from each result list, assigns each selected entry a scoring value under a scoring function, assigns each subset a representative value based on its entries' scoring values, and produces a merged list in a predetermined manner based on the representative value assigned to each result list, with the representative value varying in accordance with that predetermined manner. Google Patents lists the '704 patent as expired on March 27, 2022.

Corroboration: Word metadata counts as independent evidence

To antedate Bushee, Valtrus relied on a declaration from one of the inventors, invention disclosure documents, and the Microsoft Word metadata of those documents. Google argued that the documents and their metadata were all within the inventor's control and could not corroborate his testimony. The court rejected that argument. It restated that a party relying on an inventor's testimony to prove conception "must proffer evidence, in addition to the inventor's own statements and documents, corroborating the inventor's testimony," quoting Apator Miitors ApS v. Kamstrup A/S, 887 F.3d 1293, 1295 (Fed. Cir. 2018), and that the sufficiency of corroboration is judged under a rule of reason. It then held that the metadata generated by Microsoft Word "was not authored by" the inventor, citing Global Health Solutions LLC v. Selner, 148 F.4th 1363, 1374 (Fed. Cir. 2025), and that "Microsoft Word metadata can provide independent corroboration of inventor statements and documents contained in Word files." The court assumed, without deciding, that the metadata was authentic. It distinguished cases rejecting unwitnessed laboratory notebooks and unwitnessed emails and drawings, and noted that Google's counsel acknowledged at oral argument that a human is not a required element of corroboration.

Diligence across an 11-business-day gap

Google contested diligence only for the period from August 8, 2001, when the last of four inventors signed the inventor declaration, to the August 27, 2001 filing date, a span of about 11 business days. Quoting Perfect Surgical Techniques, Inc. v. Olympus America, Inc., 841 F.3d 1004, 1009 (Fed. Cir. 2016), the court said the patent owner "must show there was reasonably continuous diligence," which does not require proof of activity on every day. It held that substantial evidence supports the Board's finding. The last signature came from an inventor based in Ontario, Canada, whose signed declaration had to be mailed back to the law firm in California, and Valtrus's expert testified that law firms generally take several weeks or more to draft and finalize an application. The court distinguished In re Mulder, 716 F.2d 1542 (Fed. Cir. 1983), where a draft application had been prepared for nearly three months and the record showed no activity of any kind in the United States.

The parallel district case

The '704 patent is also part of a district court fight between the same companies. In Valtrus Innovations Ltd. v. Google LLC, No. 5:26-cv-02379-PCP (N.D. Cal.), Judge P. Casey Pitts granted Google's motion to dismiss on August 10, 2026. The order holds the asserted claims of the '704 patent (claims 1-6, 12, 13, and 15-17), together with asserted claims of U.S. Patents 7,346,604 and 6,816,809, ineligible under 35 U.S.C. 101, and dismisses with prejudice and without leave to amend. The order recounts earlier Valtrus suits against Google first filed in the Northern District of Texas in January 2022 and later transferred to the Northern District of California as No. 5:25-cv-07063-PCP. Valtrus's appeal from the August 10 order is docketed at the Federal Circuit as No. 2026-2160. The October 19 decision leaves claims 1-23 standing after the Board challenge, while the eligibility ruling against the asserted claims is on appeal.

Practice pointers

Keep invention disclosures in native file form with their metadata. The court treated the author and date fields that Word generates automatically as evidence independent of the inventor, at least where authenticity is not contested. For pre-AIA priority contests, document each stretch between conception and filing, including signature logistics and the time the law firm took to finalize the application.

What to watch next

Watch for any petition for rehearing in No. 2024-1945, for Valtrus's opening brief in No. 2026-2160, and for how the Board and district courts apply the metadata holding in other pre-AIA priority disputes.