Federal Circuit Reverses Patent Board in X-Ray Magnification Case
The Federal Circuit reversed a Patent Trial and Appeal Board’s (PTAB or Board) determination that Carl Zeiss failed to prove that patent claims to X-ray imaging systems incorporating projection magnification were invalid as anticipated by a scientific paper describing the use of X-ray beams to image rodent organs.
The case is Sigray, Inc. v. Carl Zeiss X-Ray Microscopy, Inc.
Zeiss owns U.S. Patent No. 7,400,704, which claims X-ray imaging systems that incorporate projection magnification.
As the court explained,
X-ray technology has long been utilized to generate visual images of internal structures otherwise invisible to the naked eye. The typical X-ray process entails: (1) an X-ray source generating an X-ray beam, (2) that beam penetrating a sample, and (3) a detector receiving the transmitted beam. The information received by the detector is used to generate an image.
The patent at issue incorporates into this process a mechanism known as projection magnification, which enlarges the generated image.
Sigray filed a petition with the US Patent and Trademark Office (USPTO) requesting inter partes review of all claims of that patent.
Claim 1 recites:
An x ray imaging system, comprising:a projection x ray stage including:
an x ray source generating a diverging x ray beam; and
a scintillator for converting the x ray beam, after interacting with a sample, into an optical signal;
an optical stage including:
a detector; and
a magnification lens for imaging the optical signal of the scintillator onto the detector;
wherein a magnification of the projection x ray stage is between 1 and 10 times and a magnification of the optical stage is 5 or greater.
Emphasis added by the court.
Before the Board, Sigray asserted that claim 1 was anticipated by a prior art reference known as Jorgensen.
The Board granted Sigray’s petition, finding that it demonstrated a reasonable likelihood that at least one of the challenged claims was unpatentable.
On appeal, the Federal Circuit noted that “A claim is anticipated only when every claim limitation is disclosed within a single reference.”
The court explained that
Jorgensen is a scientific paper that describes using an X-ray beam to image rodent organs. It describes a system that uses an X-ray source to generate an X-ray beam, which then passes through a sample before being received by a detector. … Jorgensen attempts to reduce concerns related to projection magnification by providing a large distance between the sample and the source and a short distance between the sample and the detector. … Additionally, Jorgensen references a process known as collimation, explaining that “[t]he collimated X-ray beam is shielded by a lead-wrapped brass tube as the beam passes from the source into the shielded cover of the scanner.”
There was no disagreement that Jorgensen explicitly disclosed all limitations of claim 1, except for the projection magnification limitation: “a magnification of the projection X-ray stage... between 1 and 10 times.”
Viewing the Board’s reasoning, said the court,
we conclude it construed “between 1 and 10” to exclude small amounts of magnification. This was an error. At all times, the language of the claims govern their scope and meaning, and unless the intrinsic evidence compels a contrary conclusion, the claim language carries the meaning accorded those words in the usage of skilled artisans at the time of invention.
Thus, the court reversed the Board’s decision regarding claim 1, as well as claims 3 and 4.
