Sigray v. Carl Zeiss X-Ray Microscopy: Federal Circuit Reverses-in-Part on X-Ray Microtomography Patent
Sigray, Inc. appealed a patentability ruling against Carl Zeiss X-Ray Microscopy, Inc. over US7400704B1, covering high-resolution direct-projection x-ray microtomography systems. After 665 days, the Federal Circuit reversed-in-part, vacated-in-part, and remanded — a mixed outcome with significant implications for x-ray imaging IP.
Federal Circuit delivers mixed ruling in x-ray imaging patent dispute
Sigray, Inc. brought Case No. 23-2211 before the U.S. Court of Appeals for the Federal Circuit on July 28, 2023, challenging a patentability determination involving US7400704B1 — a patent covering a high-resolution direct-projection x-ray microtomography system capable of operating with synchrotron or laboratory-based x-ray sources. The defendant, Carl Zeiss X-Ray Microscopy, Inc., is a major commercial player in the x-ray imaging and microscopy sector, making this dispute commercially significant beyond its technical scope.
The Federal Circuit issued its ruling on May 23, 2025, ordering the lower decision reversed-in-part, vacated-in-part, and remanded. Separately, a portion of the appeal was dismissed. This compound outcome — combining reversal, vacatur, and remand — suggests the appellate panel found distinct legal errors across different claim sets or issues, correcting some directly and returning others to the originating tribunal for reconsideration consistent with the Federal Circuit’s guidance.
The 665-day duration from filing to decision is consistent with the Federal Circuit’s typical docket for contested PTAB invalidity appeals. The partial dismissal of the appeal limits the full scope of Sigray’s win, and the remand introduces continued uncertainty. The precise claims affected by each part of the order — and whether the remand will ultimately favour Sigray or Zeiss — remains to be resolved at the lower level. The public record does not disclose the specific claim groupings tied to each disposition.
Filing to Appeal Dismissed in Part in 665 days
665 days from filing to Federal Circuit decision — above the median for contested PTAB appeals
Federal Circuit reverses-in-part: what the mixed ruling means for both parties
What ‘reversed-in-part, vacated-in-part, remanded’ means
A Federal Circuit order that is reversed-in-part means the appellate panel found reversible legal error in a discrete portion of the lower tribunal’s decision and corrected it outright. The vacated-in-part portion nullifies a separate segment of that decision without substituting a new ruling — instead sending it back (remanding) for the lower tribunal to reconsider. The partial dismissal further narrows the scope of issues resolved on the merits.
Mixed appellate dispositionSigray achieves partial vindication — but remand keeps outcome open
As appellant, Sigray, Inc. secured a partial win: the Federal Circuit found legal error in at least one component of the patentability ruling below, reversing it in Sigray’s favour. The vacated-and-remanded portion means Sigray has a second opportunity on remaining issues at the lower level. However, the partial dismissal indicates some of Sigray’s appellate arguments did not survive threshold scrutiny, limiting the scope of its victory.
Partial reversal for patent holderZeiss loses ground on appeal but retains live arguments on remand
Carl Zeiss X-Ray Microscopy, Inc. faces a less favourable landscape following the Federal Circuit ruling. The reversal-in-part directly overturns a portion of the outcome that had been in Zeiss’s favour. The remand, however, is not a final loss — Zeiss retains the opportunity to prevail on the vacated issues in the proceedings below. The dismissed portion of the appeal is a procedural boundary that does not resolve those underlying questions adversely to either party on the merits.
Partial loss, remand proceedings pendingX-ray microtomography IP landscape remains unsettled pending remand
The Federal Circuit’s mixed ruling signals that US7400704B1 survived at least part of the invalidity challenge — suggesting the patent retains enforceability over some contested claims. For competitors and licensees in the x-ray microscopy and microtomography sector, this creates continued uncertainty: the remand may alter which claims stand. Parties evaluating freedom-to-operate or licensing positions relative to this patent should monitor the remand proceedings closely before drawing firm conclusions.
Enforceability partially confirmedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Sigray, Inc. | Company | X-ray optics and imaging technology company — holder of US7400704B1Search in Eureka ↗ |
| Defendant | Carl Zeiss X-Ray Microscopy, Inc. | Company | Carl Zeiss X-Ray Microscopy, Inc. — commercial x-ray microscopy and imaging systems manufacturerSearch in Eureka ↗ |
| Plaintiff counsel | Alan Grayson Laquer | Attorney | Counsel for Sigray, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Craig S. Summers | Attorney | Counsel for Sigray, Inc.Search in Eureka ↗ |
| Plaintiff counsel | James Youngblood | Attorney | Counsel for Sigray, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Knobbe Martens Olson & Bear, LLP | Law Firm | Representing Sigray, Inc.Search in Eureka ↗ |
| Defendant counsel | Charles Neville Reese | Attorney | Counsel for Carl Zeiss X-Ray Microscopy, Inc.Search in Eureka ↗ |
| Defendant counsel | John C. Phillips | Attorney | Counsel for Carl Zeiss X-Ray Microscopy, Inc.Search in Eureka ↗ |
| Defendant counsel | Kurt Louis Glitzenstein | Attorney | Counsel for Carl Zeiss X-Ray Microscopy, Inc.Search in Eureka ↗ |
| Defendant counsel | Ryan Patrick O’Connor | Attorney | Counsel for Carl Zeiss X-Ray Microscopy, Inc.Search in Eureka ↗ |
| Defendant law firm | Fish & Richardson LLP | Law Firm | Representing Carl Zeiss X-Ray Microscopy, Inc.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Court of Appeals for the Federal CircuitSearch in Eureka ↗ |
Official order — verbatim text
The order — ‘REVERSED-IN-PART, VACATED-IN-PART, AND REMANDED’ — reflects a differentiated appellate review of distinct issues within the patentability challenge. At the Federal Circuit, reversal requires the panel to find that the lower tribunal’s determination was legally erroneous and that the correct outcome is determinable without further fact-finding. Vacatur-with-remand, by contrast, signals that while error existed, resolution requires the lower tribunal to apply corrected legal standards to the record. The partial dismissal further constrains the issues addressed on the merits, suggesting some appellate arguments failed jurisdictional or procedural thresholds. Together, this disposition partially restores Sigray’s patent position while leaving a subset of validity questions unresolved.
US7400704B1 — High-resolution direct-projection x-ray microtomography system
US7400704B1, filed under application number US11/537806, claims a high-resolution direct-projection x-ray microtomography system designed to operate with either synchrotron radiation or conventional laboratory-based x-ray sources. This dual-source compatibility is technically significant: synchrotron sources produce highly collimated, monochromatic beams enabling exceptional resolution, while laboratory-based sources make the technology commercially accessible outside major research facilities. The patent thus covers a broad deployment spectrum in precision imaging.
In the analytical instrumentation and semiconductor inspection sectors, x-ray microtomography patents carry substantial commercial weight. High-resolution tomographic imaging is integral to non-destructive testing, materials characterisation, and advanced semiconductor metrology — markets where Carl Zeiss X-Ray Microscopy is a direct competitor. A patent that survives Federal Circuit review, even partially, represents a credible enforcement asset. Competitors developing direct-projection tomography architectures or synchrotron-compatible optics should assess their exposure against the claims confirmed valid on appeal.
Should you run an FTO against US7400704B1?
Any organisation developing or commercialising high-resolution x-ray microtomography systems — whether for semiconductor inspection, materials science, or biomedical imaging — should assess freedom-to-operate against US7400704B1. The Federal Circuit’s partial reversal in Sigray’s favour confirms that at least a subset of claims survived an invalidity challenge mounted by a major industry player. Products utilising direct-projection architectures or hybrid synchrotron/laboratory x-ray source designs are most directly in scope.
PatSnap Eureka’s FTO Search Agent can rapidly map the claim language of US7400704B1 against your product specifications, surfacing relevant prior art, claim construction history from the IPR or PTAB record, and analogous cases involving x-ray imaging patents at the Federal Circuit. For IP teams monitoring the remand proceedings, Eureka’s litigation tracking tools provide real-time alerts when the lower tribunal issues a new determination — critical for updating FTO assessments before product launch.
Run a freedom-to-operate analysis on US7400704B1 to assess your product’s exposure
Run FTO in Eureka →Similar Federal Circuit patentability appeals in x-ray imaging and instrumentation
Explore Federal Circuit appeals involving patentability challenges to x-ray imaging, microtomography, and analytical instrumentation patents with comparable reversal or remand outcomes.
What this case signals for the x-ray imaging and microscopy IP landscape
A Federal Circuit mixed reversal in a patentability dispute over x-ray microtomography sends layered signals to IP teams across the sector.
Partial reversal signals genuine claim strength in x-ray microtomography IP
The Federal Circuit’s willingness to reverse — not merely remand — a portion of the patentability ruling suggests Sigray’s patent claims had identifiable legal merit that the lower tribunal failed to credit correctly. For patent holders in precision imaging and analytical instrumentation, this outcome reinforces the value of appealing adverse PTAB or district court patentability rulings when claim construction or prior art analysis appears deficient.
Remand creates a window for Zeiss to defend invalidity arguments below
The vacated-and-remanded component means this dispute is not over. Carl Zeiss X-Ray Microscopy retains live arguments on the issues sent back for reconsideration. Companies monitoring this space — whether as potential licensees, competitors, or litigation targets — should not treat the Federal Circuit’s order as a final resolution of US7400704B1’s validity across all contested claims.
Sigray v Carl — key questions answered
The Federal Circuit issued a mixed ruling: reversed-in-part, vacated-in-part, and remanded on May 23, 2025. A portion of the appeal was also dismissed. This means the court found legal error in part of the lower patentability determination, correcting some issues outright while returning others for further proceedings. US7400704B1 — covering x-ray microtomography systems — retains at least partial validity following the decision.
US7400704B1 is a U.S. patent held by Sigray, Inc. covering a high-resolution direct-projection x-ray microtomography system compatible with both synchrotron and laboratory-based x-ray sources. The patent is relevant to precision non-destructive imaging, semiconductor inspection, and materials characterisation markets. Its dual-source compatibility distinguishes it from systems limited to synchrotron-only or laboratory-only configurations.
A Federal Circuit disposition of reversed-in-part means the panel found clear legal error in one component of the lower decision and corrected it directly. Vacated-in-part means a separate portion of the decision is nullified but requires the lower tribunal to reconsider under corrected legal standards rather than being resolved by the appellate court itself. Remand returns the case to the originating body — typically the PTAB — for further proceedings on the vacated issues.
The partial dismissal of the appeal means some of Sigray’s appellate arguments were not resolved on their merits — likely failing jurisdictional or procedural requirements. This limits the scope of the Federal Circuit’s ruling and means certain issues raised by Sigray were not adjudicated. The dismissed portion does not represent a substantive ruling in favour of either party on those specific points.
Companies developing or selling high-resolution x-ray microtomography systems should conduct a claim-level freedom-to-operate analysis against US7400704B1, focusing on claims confirmed valid by the Federal Circuit reversal. The ongoing remand means the full validity picture is not yet resolved. Monitoring the lower tribunal’s subsequent decision is advisable before finalising FTO conclusions or licensing strategies related to direct-projection x-ray architectures.
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