Sigray, Inc. v. Carl Zeiss X-Ray Microscopy, Inc
Authored by: Jeremy J. Gustrowsky
In a recent decision, the Federal Circuit addressed the proper interpretation of patent claims relating to X-ray imaging technology, specifically focusing on U.S. Patent No. 7,400,704, owned by Carl Zeiss X-Ray Microscopy, Inc. The patent covers X-ray imaging systems that use projection magnification to enlarge images. Sigray, Inc. challenged the validity of several claims in this patent, arguing that an earlier scientific publication (the Jorgensen reference) already disclosed the key features of the invention.
The heart of the dispute was whether the Jorgensen reference inherently disclosed a “magnification of the projection X-ray stage … between 1 and 10 times,” as required by the patent. The Patent Trial and Appeal Board (PTAB) had previously sided with Zeiss, finding that Jorgensen did not meet this limitation because any magnification present was too small to count. However, the Federal Circuit disagreed, finding that the PTAB had improperly narrowed the claim scope. The court explained that even tiny, almost undetectable amounts of magnification—so long as they are between 1 and 10—fall within the claim’s language.
The Federal Circuit concluded that the Jorgensen reference did, in fact, inherently disclose the required magnification, because the X-ray beams described in Jorgensen were not perfectly parallel and would naturally result in some level of magnification. As a result, the court reversed the PTAB’s decision regarding claims 1, 3, and 4, finding them unpatentable as anticipated by Jorgensen. The case was sent back to the PTAB to reconsider whether the remaining claims (2, 5, and 6) would have been obvious in light of this ruling.
This decision highlights the importance of precise claim construction in patent law and serves as a reminder that courts will not read limitations into claims that are not supported by the patent’s language or intrinsic evidence. Even very small, inherent features in prior art can be enough to invalidate a patent claim if the claim language is broad enough to cover them.