Section 112(f) - Friend or Foe?

There has been much political action in the patent world regarding Section 101 - some say it is a quagmire of nonsense, while others allege all is fine and there is “nothing to see here.” But there is also considerable chatter regarding Section 112(f), and that is very interesting from the day-to-day prosecution point of view.

Why you ask? Because the “conventional wisdom” among patent practitioners (at least those with a registration number over 30,000) is that so-called “means” claims are too narrow and should be avoided. Various commentators (see post here citing Patently-O post here) have illustrated with data how use of means claims has been declining for decades, presumably because no practitioner worth their salt would be caught dead using such claim language. Even the USPTO examiners have jumped on the bandwagon (see post here), using allegations of Section 112 interpretations to put limits on claim scope during prosecution.

But if means claims are such a poor vehicle to obtain patent protection, and if their usage by practitioners has been on a nose dive for years, why would the anti-patent lobby be putting so much effort into further restricting section 112? A cynical view could be that, in reality, strategically drafted means claims are still a nightmare for defendants in litigation. Even with the restrictive analysis of the claims being limited to the structure disclosed in the specification and equivalents thereof, such an interpretation still provides the cunning patent drafter and prosecutor with a lot of leash. Plus, as we have discussed in the previous post linked above, even the troublesome Broadest Reasonable Interpretation cannot undue a means claim interpretation in prosecution, meaning that the Examiner must form a rejection that considers the claim scope as limited to the structure in the specification (and equivalents thereof).

As noted in MPEP 2181:

Identifying and Interpreting a 35 U.S.C. 112(f) or Pre-AIA 35 U.S.C. 112, Sixth Paragraph Limitation

This section sets forth guidelines for the examination of 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, “means or step plus function” limitations in a claim. … The Court of Appeals for the Federal Circuit, in its en banc decision In re Donaldson Co., 16 F.3d 1189, 1194, 29 USPQ2d 1845, 1850 (Fed. Cir. 1994), held that a “means-or-step-plus-function” limitation should be interpreted as follows:

Per our holding, the “broadest reasonable interpretation” that an examiner may give means-plus-function language is that statutorily mandated in paragraph six. Accordingly, the PTO may not disregard the structure disclosed in the specification corresponding to such language when rendering a patentability determination.

Therefore, the broadest reasonable interpretation of a claim limitation that invokes 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is the structure, material or act described in the specification as performing the entire claimed function and equivalents to the disclosed structure, material or act. As a result, section 112(f) or pre-AIA section 112, sixth paragraph, limitations will, in some cases, be afforded a more narrow interpretation than a limitation that is not crafted in “means plus function” format.

When used strategically, means claims can help not only with providing flexibility in avoiding the prior art while still covering the allegedly infringing product, but it can also help with clarity and indefiniteness issues.

So, if those seeking to limit patent protection have listed 112(f) as their #2 priority (right behind keeping Section 101 available as a catch-all that can be applied to shoot down almost any patent no matter the lack of prior art or any other reasonable defense), patent applicants might want to reconsider their declining use of strategic means claims.