Addressing for the first time the issue of whether the disclosure of subject matter in a document incorporated by reference amounts to a dedication of that subject matter to the public under the Johnson & Johnston disclosure-dedication rule, the U.S. Court of Appeals for the Federal Circuit reversed a district court’s summary judgment of non-infringement, holding that the host patent must first sufficiently inform one of ordinary skill that the incorporated document contains subject matter that is an alternative to a claim limitation before the dedication rule can be used to limit equivalents.  SanDisk v. Kingston Tech., Case No. 11-1346 (Fed. Cir., Oct. 9, 2012) (Prost, J.) (Reyna, J. concurring-in-part and dissenting-in-part).

SanDisk brought suit against Kingston alleging infringement of patents relating to various methods and systems for managing data in flash memory systems, including methods for reducing the wear and tear on flash memory cells.  In its doctrine of equivalents analysis the district court granted summary judgment of non-infringement on two grounds, both of which related to the disclosure-dedication rule set forth in Johnson & Johnston (IP Update, Vol. 5, No. 4): SanDisk’s proposed equivalent was dedicated to the public because one of the patents-in-suit disclosed an equivalent, and disclosure in a patent incorporated by reference in the host patent amounted to dedication of the subject matter to the public.  The Federal Circuit disagreed on both accounts. 

First, the Federal Circuit held that the disclosures in one of the patents-in-suit did not satisfy the Johnson & Johnston disclosure-dedication rule.  Under this rule, “[W]hen a patent drafter discloses but declines to claim subject matter . . . this action dedicates that unclaimed subject matter to the public.”  The Federal Circuit clarified, however, that “the disclosure must be of such specificity that one of ordinary skill in the art could identify the subject matter that had been disclosed and not claimed.”  The Federal Circuit emphasized that “before unclaimed subject matter is deemed to have been dedicated to the public, that unclaimed subject matter must have been identified by the patentee as an alternative to a claim limitation.”

Turning next to the issue of whether the disclosure of subject matter in a document incorporated by reference amounts to a dedication of that subject matter under Johnson & Johnston, the Federal Circuit held that incorporation by reference does not automatically “convert the invention of the incorporated patent into the invention of the host patent.”  Rather, a district court must first look to the teachings of the host patent in determining whether the incorporated subject matter satisfies the Johnson & Johnston disclosure-dedication rule.  First “the host patent must sufficiently inform one of ordinary skill that the incorporated document contains subject matter that is an alternative to a claim limitation.”  Only then does the inquiry shift to the incorporated document “to assess whether the disclosure of that subject matter is of such specificity that one of ordinary skill in the art could identify the subject matter that had been disclosed and not claimed.”

Practice Note:  This ruling will make it harder for defendants to satisfy the Johnson & Johnston disclosure-dedication rule when attempting to restrict application of the doctrine of equivalents.