Al-Site Corp. v. VSI International, Inc.

Magnavision, previously known as Al-Site Corporation (plaintiff) sued VSI International (VSI) (defendant) for infringement of several patents covering eyeglass-display systems that allowed customers to try on glasses and return them to their racks without removing the display hangers. Patent ’532’s claim, meaning the portion of the patent defining what the patent covered, described a “combination of eyeglasses and hanger means for removably mounting the eyeglasses on a cantilevered support.” The patent further provided some structural definition of “hanger means” and referred to a “fastening means.” The district court determined that the “fastening means” was a means-plus-function element subject to interpretation under 35 U.S.C. § 112, ¶ 6, meaning that the court was to define the scope of the claim to cover the associated structure, material, or acts plus their equivalents. Applying the court’s construction of the claim, the jury concluded that VSI literally infringed patent ’532. The claims in patents ’345, ’726, and ’911 described the combination of an eyeglass-display member and an eyeglass-hanger member. The claims further provided structural limitations for performing the function of mounting a pair of glasses. However, the district court concluded that the “eyeglass hanger member” was a means-plus-function claim subject to § 112, ¶ 6, and provided its own construction of what the claim covered. Applying that construction, the jury did not find that VSI literally infringed the patents, but found that infringement existed under the doctrine of equivalents. Magnavision appealed, arguing that the district court construed the claims too narrowly in patents ’345, ’726, and ’911 and that, if construed correctly, VSI literally infringed those patents.