Originally published July 15, 2005

On July 12, 2005, the United States Court of Appeals for the Federal Circuit, sitting en banc, addressed the extent to which courts should resort to and rely on a patent’s specification in construing its claims. See Phillips v. AWH Corporation, et al., Nos. 03-1269, 1286 (Fed. Cir. (D. Colo.) July 12, 2005). The Federal Circuit emphasized the importance of the patent specification in claim construction, and in doing so, criticized its prior ruling in Texas Digital Systems, Inc. v. Telegenix, Inc., 308 F.2d 1193 (Fed. Cir. 2002).

In Texas Digital, the Federal Circuit essentially reduced the role of the specification in claim construction to serving as a check on the dictionary meaning of a claim term. Specifically, the Texas Digital Court held that the specification should be consulted only after a determination is made as to the ordinary meaning(s) of the claim term in dispute, whether based on a dictionary, treatise or other source. Even then, the Federal Circuit advised that the specification should be consulted only to determine whether it disavows one of the meanings derived from the dictionary or contains a specific alternative definition.

In Phillips, the Federal Circuit concluded that the Texas Digital approach "improperly restricts the role of the specification," and contradicts its previous rulings that the specification is the "single best guide" to construing claims. The Court logically found that the problem of using dictionaries in claim construction is that they focus the inquiry on the abstract meaning of words rather than on the meaning of claim terms in the context of the patent. As such, the Court warned that reliance on dictionary definitions could cause the construction of a claim to be unduly expansive.

To reduce the risk of such "systematic overbreadth," the Phillips Court noted that courts should, at the outset, focus on how the patentee used the claim term in the claims, the specification and the prosecution history, rather than starting with a broad dictionary definition to be whittled down. Ironically, this reverses the order recommended by the court in the Texas Digital case.

The Phillips opinion does not preclude the use of dictionaries or other extrinsic sources in construing claims, nor does it prescribe a specific sequence in which judges should consult various sources. However, it does emphasize the weight that should be given to such sources, interpretation of a claim unless considered in the context of the specification.

Practitioners had hoped that the Phillips opinion would provide more certainty to the ever-important claim construction process. Not so. Instead, the majority opinion acknowledges that the decision fails to clarify the claim construction process, leaving the real analysis to be done on a case-by-case basis. The bottom line here is that careful patent drafting is now more important than ever. Under Phillips, the specification will now, more than ever, shape the meaning of the claims. A talented patent drafter can help ensure that the specification accurately reflects the full scope of the intended meaning of important claim elements and limitations.

© 2005 Sutherland Asbill & Brennan LLP. All Rights Reserved.

This article is for informational purposes and is not intended to constitute legal advice.