“Means-plus-function” Claim Indefinite For Lack Of Corresponding Structure

PatentlyOImage005Default Proof Credit Card System v. Home Depot (Fed. Cir. 2005).

By Richard Machonkin

Default Proof sued Home Depot, and other defendants, claiming that the defendants’ gift cards infringed a patent directed to a system for dispensing and validating prepaid debit and credit cards. The district court held on summary judgment that claim 1 was indefinite and, therefore, invalid, because the specification did not disclose any structure corresponding to the limitation “means for dispensing at least one debit card for each transaction.” The Federal Circuit affirmed.

The Federal Circuit explained that in order for a means-plus-limitation to meet the definiteness requirement of § 112, there must be structure disclosed in the specification that is “clearly linked to and capable of performing the function claimed by the means-plus-function limitation.” The Federal Circuit concluded that the specification did not disclose any such structure. A point-of-sale (POS) terminal disclosed in the specification did not constitute corresponding structure because the specification did not clearly link the POS terminal, or any part of it, to the function of dispensing debit cards, nor did the specification describe any parts of the POS terminal capable of dispensing debit cards.

Testimony from Default Proof’s witness that the POS terminal included structures corresponding to the “means for dispensing” was unavailing. A patent specification need not disclose details of structures well known in the art, but must nonetheless disclose some structure. Thus, when a specification discloses some corresponding structure, expert testimony can be used to elaborate on the disclosure. In this case, however, the specification did not disclose any structure capable of dispensing debit cards. The testimony of Default Proof’s witness could not make up for the total absence of such structure from the specification.

NOTE: Richard Machonkin is a partner at McDonnell Boehnen Hulbert & Berghoff LLP.  Rick has litigated patent and trademark cases in federal courts and before the International Trade Commission and the Trademark Trial and Appeal Board.  He has also prosecuted patent applications and rendered opinions on issued patents in a variety of technologies. [Brief Bio]