Indefiniteness Risks in "Means" Claims for Software Inventions

This article first appeared in Orange County Lawyer Vol. 57, No. 8 on August 1, 2015

By John Giust

Recently, in Eon Corp v. AT&T Mobility, Inc. (Fed. Cir. May 6, 2015), the Federal Circuit addressed the intersection of indefiniteness law with "means plus function" claiming. The Federal Circuit panel affirmed the invalidation of certain asserted "means" claims as indefinite because the patent specification lacked a disclosure of algorithms which could carry out the claimed functions.

In patent claiming, applicants are permitted under 35 U.SC.§ 112, p¶ 6 to claim a "means" for carrying out a function, so long as they disclose the structure for carrying out the function in the patent specification. In such a case the patent claim term would cover all the structures disclosed in the specification and all equivalent structures.

In Eon Corp, the Plaintiff's claims contained numerous software "means" terms, such as "means for establishing a first menu," but the plaintiff's disclosure contained only a generic description of using a computer.No particular algorithms for carrying out any of the functions (such as establishing a menu) were disclosed.

The Federal Circuit first recognized the numerous "means" terms, and sought to identify the relevant disclosed structure: "It is well established that the corresponding structure for a function performed by a software algorithm is the algorithm itself." (citing WMS Gaming, Inc. v. Int'l Game Tech., 184 F.3d 1339, 1348-49 (Fed. Cir. 1999). Failing to find any disclosed algorithm at all, the Federal Circuit addressed the so-called "Katz exception" for computer programs.

Katz held that a standard microprocessor can serve as sufficient structure for "functions [that] can be achieved by any general purpose computer without special programming." Katz, 639 F.3d at 1316. However, this exception is limited to those few functions a general purpose computer can accomplish on its own without any programming, such as reading data. "A microprocessor or general purpose computer lends sufficient structure only to basic functions of a microprocessor. All other computer-implemented functions require disclosure of an algorithm." (Slip. Op., at 11). Since the functions at issue were not native to a generic processor, the Katz exception was not available.

Moreover, it is irrelevant if the undisclosed algorithms are so simple that person of ordinary skill could implement the function without any difficulty:

EON also argues that a microprocessor can serve as sufficient structure for a software function if a person of ordinary skill in the art could implement the software function. This argument is meritless. In fact, we have repeatedly and unequivocally rejected this argument: a person of ordinary skill in the art plays no role whatsoever in determining whether an algorithm must be disclosed as structure for a functional claim element. See Noah Sys. v. Intuit Inc., 675 F.3d 1302, 1313 (Fed. Cir. 2012); Blackboard, 574 F.3d at1385; Aristocrat, 521 F.3d at 1337.

The understanding of a person of ordinary skill is instead relevant to the enablement requirement of 35 USC § 112, p¶ 1 but has no bearing on the definiteness requirements of 35 USC § 112, p¶2, 6.

"Enablement of a device requires only the disclosure of sufficient information so that a person of ordinary skill in the art could make and use the device. A section 112 paragraph 6 disclosure, however, serves the very different purpose of limiting the scope of the claim to the particular structure disclosed, together with equivalents." Aristocrat, 521 F.3d at 1336. Accordingly, "[t]he question before us is whether the specification contains a sufficiently precise description of the 'corresponding structure' to satisfy section 112, paragraph 6, not whether a person of skill in the art could devise some means to carry out the recited function." Blackboard, 574 F.3d at 1385.

While claiming in "means plus function" terms has been out-of-vogue recently, many issued patents, particularly issued software patents, contain claim terms necessitating a "means plus function" construction. In fact, "means" or similar language was often used by patent drafters to make the claims appear more structural in order to avoid section 101 rejections for software and business methods subject to scrutiny for whether or not they contained patentable subject matter. This strategy may prove fatal in cases where the specific algorithms are omitted from the patent specification.

Examination of a patent's claims for "means plus function" compliance to identify detailed support of all claimed algorithms is a necessity in patent litigation. Lacking a detailed disclosure, the patent may be invalid.