Prepared by Cislo & Thomas LLP Attorney Mark D. Nielsen, Ph.D.
1. In a recent Federal Circuit opinion, the Court ruled that a patent owner that takes contradictory positions on patent language during prosecution of that application relative to subsequent reexaminations of the same patent compromises the public notice function of patents (i.e., that patent language should be clear enough to inform the public of the scope of the patent). As a result, patent claims that contain language subject to the patent owner’s contradictory positions are invalid as indefinite under 35 U.S.C. Section 112. In this case, which related to fax machines, the district court invalidated the claims asserted in the case as indefinite, and the Federal Circuit affirmed. The takeaway here is that one should not take contradictory positions regarding the interpretation of patent claim language during prosecution relative to Patent Office reviews or litigation.
2. In another recent Federal Circuit opinion, the Court invalidated an asserted patent claim related to golf club design because it also was indefinite. For the golfers out there, the patent was directed to moving weight in the clubhead of a “wood” from the toe to the heel in order to limit hooking the ball. The issue in the patent claim language that was indefinite related to where the toe ends and where the heel begins (and other language in the patent about “radius of curvature”), and the patent language was not sufficiently clear or definite to provide the necessary “measuring stick” to determine infringement. As such, the Federal Circuit affirmed the district court’s finding of indefiniteness of the asserted patent claim.
3. In yet another recent Federal Circuit opinion, the Court affirmed a series of rulings on claim construction and summary judgment concerning a group of patents directed to synchronizing data across multiple devices that were asserted against Dropbox. The Northern District of California had found that the asserted claims of one of the patents were invalid as indefinite because they were deemed to contain mean-plus-function claim limitations under 35 U.S.C. 112, paragraph 6, but lacked adequate structure in the specification to correspond to the functions set forth in the claims. The Court also invalidated other claims as indefinite because they contained an “impossibility” – namely, generating a digital media file that comprises a directory of digital media files. The district court also found that a number of claims were not infringed. The Federal Circuit affirmed these rulings. The takeaways here from a patent prosecution standpoint are: (1) if you use means-plus-function language, make sure there is adequate corresponding structure in the specification, and (2) don’t have limitations in the claims that contain impossibilities.