Software Means-Plus-Function Claims Held Indefinite

Software patent claims were held indefinite under 35 U.S.C. § 112 where the patent specification failed to provide any algorithm for performing the recited function.  Ibormeith IP, LLC v. Mercedes-Benz USA, LLC, No. 10-5378 (D. N.J., Sept. 5, 2012).  The claims recited “computational means” and thus were means-plus-function claims within the ambit of 35 U.S.C. § 112, sixth paragraph.  Accordingly, the patent was required to disclose an algorithm or algorithms to perform the functions carried out by the computational means.  It did not.  Therefore, the claims were invalid.

U.S. Patent No. 6,313,749 is directed to a method of raising an alarm when conditions indicate that a vehicle driver may be sleepy.  For example, claim 1 of the ’749 patent recites in part:

computational means for weighting the operational model according to time of day in relation to the driver or operator circadian rhythm pattern(s) and for deriving from the weighted model, driver or operator sleepiness condition and producing an output determined thereby.

Claim 9 of the ’749 patent includes a similar recitation.  Along with their claim construction arguments, the defendants argued that claims 1 and 9 were invalid because the “computational means” limitation was indefinite.  The court then reserved its claim construction rulings and instructed the parties to brief the issue of summary judgment of invalidity for indefiniteness.

The parties agreed that three functions were implicated by the recitation of “computational means” in claim 1: “(1) 'weighting the operational model according to time of day in relation to the driver or operator circadian rhythm pattern(s)'; (2) 'deriving, from the weighted model, driver or operator sleepiness condition'; [and] (3) 'producing an output determined thereby.'”  The court examined in turn the three portions of the specification that the plaintiff argued explained these functions.

The first two portions of the specification to which the plaintiff pointed simply summarized the functions being performed, but gave no guidance as to how they were performed.  The third portion of the specification included two tables.  The first table provided an equation, and the second table purported to define terms used in the equation.  However, the patent provided no explanation for this second table, and certain terms in it were nowhere defined.  Because the patentee did not explain its “Byzantine” tables, it had not met its burden of providing structures that were linked to the claimed functions.

The court provided considerable additional discussion of how the patent failed to support the three functions claimed in claim 1, as well as the functions claimed in claim 9.  At root in every instance, however, was the patentee's failure to provide enough detail concerning the claimed function.  Explaining that a result is achieved is not enough where the patentee fails to provide a step-by-step explanation of how to achieve that result.

It is worth noting that the patent application in this case was filed in 1999.  Means-plus-function claims are less common than they used to be, and certainly are rarely used in software claims these days, for good reason (at least in the United States).  That said, whether couched in means-plus-function format or not and regardless of whether they are recognized by the PTO and courts as such, most if not all software claims rely on recitations of functionality.  Therefore it is worth bearing in mind for the patent drafter to consider whether algorithms are provided, and whether their detail is sufficient.