By Arturo E. Sandoval and Firasat M. Ali
The U.S. Court of Appeals for the Federal Circuit recently held that disclosure made in the specification of a patent application that is not expressly claimed is dedicated to the public and cannot be later captured under the doctrine of equivalents. PSC Computer Products, Inc. v. Foxconn International, Inc., Case No. 03-1089 (Fed. Cir. Jan. 20, 2004).
In this case PSC sued Foxconn for patent infringement regarding a patent that involved a retainer clip that provided a conduction path for heat to escape from a circuit. The patent-in-issue claimed a retainer clip that uses a "resilient metal strap." The patent specification stated that "the elongated strap is made of stainless steel although other resilient material may be suitable for the strap," and "other prior art devices use molded plastic."
The district court held that under the disclosure-dedication rule, PSC’s disclosure of clips made of plastic parts coupled with its failure to claim chips having plastic parts, in essence dedicated such clips to the public.
PSC contended that its disclosure in the patent specification did not warrant dedication of equivalents to the public. The Federal Circuit, in affirming the district court, dismissed PSC’s contention that the doctrine of equivalents should have been applied to the claim language "resilient metal strip" to render Foxconn’s device (which used a plastic retainer clip) as an equivalent. The Court’s rationale was that since one of the key functions of a patent claim is to place the public on notice of what the claim covers, i.e., what would infringe, expanding a claim term to cover equivalents that have been specifically disclosed, but not claimed, would be counter to the notice doctrine.
The Court agreed with PSC that under the disclosure-dedication rule of Johnson & Johnston, only a specific disclosure, not any generic reference in the disclosure, will operate to dedicate subject matter to the public. The Court explained that the disclosure must be of such specificity that one of the ordinary skill in the art could identify the subject matter that has been disclosed. Applying this rule to the language in the specification, the Court found that although the term "other resilient materials" did not dedicate all resilient materials (other than the specifically claimed stainless steel material) to the public, the categorization of plastic as a prior art, coupled with the specific disclosure of it as an alternative, operated to dedicate use of plastic chip parts to the public. In addition, since PSC had led the public to believe that its metal clip design was an improvement over the inferior prior art plastic design, PCS could not now recapture plastic as an equivalent under the doctrine of equivalence.
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