LACK OF ANTECEDENT BASIS NOT FATAL TO PATENT CLAIM:

Energizer Holdings, Inc. v. Itn'l Trade Comm. (05-1018, Jan. 25, 2005)

Energizer filed a complaint with the ITC in April 2003, charging that about two dozen companies were infringing on US Patent 5,464,709, which disclosed a mercury-free electrolytic alkaline battery cell. The company sought an ITC order that would bar the infringing batteries from being imported into the United States.

During the proceeding, the ITC considered the following:

1. An electrochemical cell comprising an alkaline electrolyte, a cathode comprising manganese dioxide as an active cathode component, and an anode gel comprised of zinc as the active anode component, wherein the cell contains less than 50 parts of mercury per million parts by weight of the cell and said zinc anode has a gel expansion of less than 25% after being discharged for 161 minutes to 15% depth of discharge at 2.88A.

The Commission held the claim invalid because "said zinc anode" did not have an antecedent basis, because the term "zinc anode" does not appear in the claim prior to the term "said zinc anode." Accordingly, the court invalidated the claim under 35 U.S.C. §112 ¶2, which requires that the patent specification shall "conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention."

The Commission added that even if "said zinc anode" is construed to have as antecedent the "anode gel comprised of zinc as the active anode component" recited earlier in the claim, the claim would still be indefinite because it requires that the anode of every cell be "discharged for 161 minutes to 15% depth of discharge at 2.88A." The Commission reasoned that since it appears that these discharge parameters are intended to apply only to a test cell, and not that every cell must be discharged, this unclear and ambiguous claim drafting renders the claim "indefinite as a matter of law." The Commission also held that the submission of alternative constructions of "said zinc anode" was an admission of indefiniteness.

The Federal Circuit disagreed, stating that, even in light of a lack of antecedent basis, if the scope of a claim would be reasonably ascertainable by those skilled in the art, then the claim would not be indefinite. Furthermore, an antecedent basis can be present by implication.

Addressing the issue of alternate construction, the Federal Circuit held that the Commission erred in holding that the need to construe a claim, or the proffer of alternative constructions, renders the claim indefinite. A claim that is amenable to construction is not invalid on the ground of indefiniteness. Relying on Exxon Research & Eng'g Co. v United States, the court repeated that "if the meaning of the claim is discernible, even though the task may be formidable and the conclusion may be one over which reasonable persons will disagree, we have held the claim sufficiently clear to avoid invalidity on indefiniteness grounds."

The case was reversed and remanded to the ITC.