If the Patentee Meant "At least" the Patentee Should Have Said At Least

Helmsderfer v. Bobrick Washroom Equipment, Inc., [2008-1027] (June 4, 2008)[MOORE, Mayer, Friedman] The Federal Circuit affirmed the district court’s decision that defendants did not infringe U.S. Patent No. 6,049,928.
SIGNIFICANCE: Different claim terms are preseumed to have different meanings.
BRIEF: After holding a Markman hearing, the district court issued an order setting forth its claim construction of seven disputed claim terms. Plaintiff objected to the construction of one term, and conceded that the construction of that term precluded a finding of infringement, upon which the district court entered an appealable final judgment of noninfringement. At issue on appeal was the district court’s construction of “partially hidden from view,” which the district court construed to mean “hidden from view to some extent but not totally hidden from view.”
Plaintiff argued that partially hidden from view included completely hidden from view. The Federal Circuit noted that plaintiff was trying to change the meaning of the limitation to at least partially hidden from view, which it rejected noting that plaintiff had used the terms “generally” and “at least” elsewhere in claim 1. Relying on the canon of construction that different claim terms are presumed to have different meanings, the Federal Circuit found that plaintiff failed to rebut the presumption that partially hidden form view (a phrase not used in the specification) meant the same thing as “generally hidden from view” which was used in the specification, or “at least partially hidden from view,” the construction it was seeking. The Federal Circuit said that if plaintiff had intended to use these terms, it should have.