Claim Differentiaion Prevents Importantion of Limitation in the Claim

Intamin Ltd. v. Magnetar Technologies, Corp., [05-1546, -1579](April 18, 2007)[RADER, Plager, Prost] The Federal Circuit vacated a finding of no infringement, and remanded the trial court's claim construction of U.S. Patent No. 6,062,350 on a braking system for amusement park rides, and affirmed the decision to vacate Rule 11 sanctions for frivolous filing of the Complaint for patent infringement.
BRIEF: At issue was whether Intamin's accused structure had intermediaries between adjacent pairs of magnets. Intamin's structure had magnets turned at 90 degrees in between the pairs of magnets, and argued that the intermediaries could not themselves be magnets.
The Federal Circuit said that to construe the claims, the court consults primarily the claims themselves in context, with much of that context supplied by the specification and the prosecution history. The Federal Circuit found that the claim does not require non-magnetic intermediaries. The Court noted that in context, a dependent claim specified that the intermediary was non magnetic. The Federal Circuit said that this shows both that the claim drafter perceived the difference between magnetic and non-magnetic and that claim 1 implied embraced non-magnetic intermediaries. Even without claim differentiation (which was not raised until a request for reconsideration) the Federal Circuit found the overall context showed that the claim was not limited to non-magnetic intermediaries. The Federal Circuit pointed to parts of the description where the patentee discussed a non-magnetic intermediary, and found that this did not limit the broader claim language, because the overall context of the patent does not specifically disavow magnetic intermediaries. In construing "length" Intamin argued that an interpretation would not cover some of the preferred embodiments. However, the Federal Circuit said that a claim need not cover all embodiments. The Federal Circuit also rejected Intamin's argument that the claim construction was wrong because it rendered dependent claim 10 invalid, but the Federal Circuit has no problem concluding that Claim 10 was an improper dependent claim.
CANONS: Claim differentiation shows that drafter specifically contemplated the difference, and the broader claim was not limited to the same scope as the dependent claim.