Carl Zeiss X-Ray Microscopy, Inc. v. Sigray, Inc.

Background

Carl Zeiss X-Ray Microscopy, Inc. sued Sigray, Inc. for infringement of U.S. Patent Nos. 7,057,187 and 7,400,704. The patents concern x-ray microscopy, including scintillators that convert high-energy x-rays into lower-energy visible light and an x-ray imaging system that uses multiple types of magnification and motion stages. The parties disputed the meaning of three terms in the patents and submitted competing proposed interpretations.

Legal standard

The court explained that claim construction—the legal interpretation of patent claims—is a question of law for the court. It considered the claim language, the patent specifications, the prosecution history, and potentially other evidence. The court emphasized that claim terms generally receive their ordinary meaning to a person skilled in the relevant field, read in the context of the entire patent.

Rulings on the disputed terms

’187 Patent, claim 1

For the phrase “a substrate for spacing the scintillator material from the lens system,” Zeiss proposed “a substrate to ensure a stable distance between the scintillator material and the lens system.” Sigray proposed requiring the substrate to be attached to the scintillator material on one side and the lens system on the other.

The court adopted Zeiss’s construction. It relied on the specification’s statement that the substrate ensures a highly stable distance between the scintillator material and the objective lens system. The court concluded that “spacing” does not require attachment. It also determined that Sigray’s construction would improperly import limitations from a preferred embodiment and would make other claim language redundant.

’704 Patent, claim 7

For the phrase “x-y-z axis motion stages to center the sample’s region of interest at the rotation axis of the rotation stage,” Zeiss proposed a construction requiring a set of motion stages that collectively can perform that centering. Sigray sought to add that the centering must occur in each of the x, y, and z axes.

The court adopted Zeiss’s construction: “a set of motion stages that collectively can be operated to center the sample’s region of interest at the rotation axis of the rotation stage.” The court found Sigray’s added language unnecessary and potentially confusing because the rotation axis may itself run along one of those directions. The court stated that the adopted construction accommodates any orientation of the rotation axis.

’704 Patent, claim 10

For the phrase “further comprising a y-axis sample motion stage for adjusting a vertical height sample in the x ray beam,” Zeiss proposed a y-axis stage that can adjust the sample’s vertical height. Sigray proposed requiring that stage to be separate from any y-axis stage included in the x-y-z motion stages described in claim 7.

The court adopted Zeiss’s construction: “further comprising a y-axis sample motion stage that can be operated to adjust a vertical height of the sample in the x-ray beam.” The court reasoned that claim 10 did not use the separate-structure language found elsewhere in claim 7 and therefore did not require a new, separate y-axis motion stage.

Disposition and effect

The court entered a claim construction order adopting Zeiss’s proposed construction for all three disputed terms. This order determines how those patent terms will be understood in the infringement case. The opinion does not state that the court decided whether Sigray infringed either patent. Judge Edward J. Davila signed the order.