On May 23, 2025, the Federal Circuit issued a precedential decision in Sigray, Inc. v. Carl Zeiss X-Ray Microscopy, Inc., Case No. 2023-2211, reversing in part a final decision by the Patent Trial and Appeal Board’s (“PTAB”) in an inter partes review (“IPR”) of U.S. Patent No. 7,400,704 (“the ’704 Patent”).  In its decision, the Federal Circuit held that (a) the PTAB implicitly construed claim 1 of the ’704 Patent; (b) the PTAB’s claim construction erroneously narrowed a limitation of claim 1; and (c), claim 1 was anticipated by a prior art reference Jorgensen because the claimed limitation was inherently disclosed.

The decision arose from an IPR initiated by Sigray, Inc. (“Sigray”), challenging the validity of all claims of the ’704 patent, which relates to X-ray imaging systems using projection magnification.  The PTAB had upheld the patent’s validity, finding that the asserted claims had not been shown to be unpatentable.

In the IPR, it was agreed by the parties that projection magnification is the result of diverging rays interacting with a sample, and uncontested that Jorgensen describes creation of a diverging beam that passes through a collimator before reaching the sample.  According to Sigray, the collimator of Jorgensen reduced but did not eliminate the divergence, thus inherently disclosing “wherein a magnification of the projection X ray stage is between 1 and 10 times” as recited in claim 1 of the ’704 patent.  Although the patent owner, Carl Zeiss X-Ray Microscopy, Inc. (“Zeiss”), conceded that a beam that is diverging (even by an undetectable amount) will result in some magnification, Zeiss asserted that the claimed magnification was not inherently disclosed because the divergence was completely eliminated by the collimator of Jorgensen.  After considering the evidence, the PTAB concluded that claim 1 was not found to be unpatentable based on determining that “[Sigray] … fails to show that the collimated X-ray beam in Jorgensen diverges enough to result in projection magnification ‘between 1 and 10 times,’ as claimed.”

On appeal, the Federal Circuit determined that the PTAB had implicitly narrowed the magnification claim limitation., despite the Board stating that it was not engaging in claim construction, because statements of non-engagement in claim construction are “not dispositive as to whether claim construction occurred” (citing Google LLC v. EcoFactor, Inc., 92 F.4th 1049, 1056 (Fed. Cir. 2024)), and “[i]f the outcome of the Board’s analysis establishes the scope and meaning of the claim, then the Board has implicitly construed the claim.”

More particularly, in this case, the Federal Circuit held that the PTAB’s analysis that “[Sigray] … fails to show that the collimated X-ray beam in Jorgensen diverges enough to result in projection magnification ‘between 1 and 10 times,’ as claimed” demonstrated that the PTAB implicitly construed the limitation to exclude magnification generated by small amounts of divergence.  In further support of its conclusion, the Federal Circuit noted that evidence relied upon by the PTAB supported a finding of some divergence in Jorgensen, which was understood to lead to at least a minute amount of magnification.  For example, the Federal Circuit relied on the fact that, according to the PTAB, the evidence of record confirms that collimation is a technique for “minimizing beam divergence so as to provide a nearly parallel X-ray beam,” and on testimony from Zeiss’s expert (e.g., “no meaningful divergence”) implying some divergence in Jorgensen.

The Federal Circuit further held that the PTAB’s claim construction was erroneous because “[t]he plain meaning of ‘between 1 and 10’ includes tiny, even undetectable, magnification, and Zeiss has pointed to nothing compelling a contrary conclusion.”

After construing the claim limitation to have its plain meaning, the Federal Circuit held that claim 1 was anticipated by Jorgensen based on determining that Jorgensen inherently disclosed the claimed magnification by disclosing an X-ray beam having at least a small amount of divergence.  In its determination of inherent disclosure, the Federal Circuit relied on its prior decision in SmithKline Beecham Corp. v. Apotex Corp., 403 F.3d 1331 (Fed. Cir. 2005), and noted that “Jorgensen’s aspirational statements of purpose that it is not attempting to achieve magnification does not address whether magnification is inherently present” and that “[a]ny presence of the limitation in the reference inherently discloses it for the purposes of anticipation.”

Based on these findings, the Federal Circuit reversed the PTAB’s decision regarding claims 1 and 3-4, vacated the PTAB’s decision regarding claims 2 and 5-6, and remanded the case for determination as to whether claims 2 and 5-6 would have been obvious.