Source: https://www.patentdocs.org/2014/06/triton-tech-of-texas-llc-v-nintendo-of-america-inc-fed-cir-2014.html?cid=6a00d83451ca1469e201a73ddb6481970d
Timestamp: 2019-04-25 10:11:01+00:00

Document:
A very experienced patent attorney once told me that you should never write means-plus-function claims unless there is a Luger at your temple. This, the first opinion addressing indefiniteness to come from the Federal Circuit since the Supreme Court weighed in on the subject in Nautilis v. Biosig Instruments, does nothing to make one question the wisdom of that advice.
Triton sued Nintendo in the Western District of Washington, alleging infringement of U.S. Patent No. 5,181,181. Particularly, Triton contended that Nintendo's Wii Remote, in combination with other aspects of the Wii video game system, infringed several claims of the '181 patent.
The '181 patent is directed to an input device that includes "components for determining its position, attitude, and motion." These components may be, for instance, "three accelerometers and three rotational rate sensors for measuring linear acceleration along, and rotational velocity about, three orthogonal axes." Each asserted claim recites "[an] integrator means associated with said input device for integrating said acceleration signals over time to produce velocity signals for linear translation along each of . . . first, second and third axes . . . ."
The specification of the '181 patent discloses that a general-purpose microprocessor and an associated memory would facilitate this function. With respect to details of the integration, however, the specification was silent.
The District Court held the claims invalid for indefiniteness. Triton appealed.
Writing for a panel consisting of herself, Judge Reyna, and Judge Hughes, Federal Circuit Judge Moore began by noting that means-plus-function claiming under 35 U.S.C. § 112, paragraph 6 requires that the "specification . . . disclose with sufficient particularity the corresponding structure for performing the claimed function and clearly link that structure to the function." Further, "[i]f the function is performed by a general purpose computer or microprocessor, then the specification must also disclose the algorithm that the computer performs to accomplish that function . . . failure to disclose the corresponding algorithm for a computer-implemented means-plus-function term renders the claim indefinite."
The trade-off of means-plus-function claims in the computing arts is that the patentee can claim an outcome rather than the steps required to obtain that outcome. But, to counteract the breadth of such claims, the patentee must disclose at least one algorithm for performing the steps. The scope of the claims will be limited to the disclosed algorithm(s) and their equivalents.
Without an algorithm for integration in the specification of the '181 patent, Triton found itself in a difficult situation. First, Triton contended that the phrase "numerical integration" implicitly disclosed an algorithm, because such algorithms are well known to those of skill in the art. This, of course, is true -- integration is a basic calculus operation, and numerical integration algorithms are undergraduate textbook material.
Judge Moore differed though, and asserted that "merely using the term 'numerical integration' does not disclose an algorithm -- i.e., a step-by-step procedure -- for performing the claimed function." Instead, she agreed with the District Court that numerical integration "is not an algorithm but is instead an entire class of different possible algorithms used to perform integration." Thus, the claim was not appropriately limited to the corresponding structure for performing the claimed function. The fact that one of skill in the art could choose an appropriate well-known algorithm was immaterial because the '181 patent failed to disclose any such algorithm.
Triton made a second argument that the specification did actually disclose an algorithm, though somewhat indirectly. Judge Moore quickly disposed of this point because Triton had not properly raised it in the District Court proceedings.
This outcome should not be surprising to anyone. In Aristocrat v. IGT, the Federal Circuit warned against conflating the enablement requirement of 35 U.S.C. § 11, paragraph 1 with the disclosure requirement of 35 U.S.C. § 112, paragraph 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."
In Nautilus, the Supreme Court held that "[a] patent is invalid for indefiniteness if its claims, read in light of the patent's specification and prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention." The claims at issue in Nautilus did include some means-plus-function language. That holding however, apparently does not address the additional disclosure requirement of 35 U.S.C. § 112, paragraph 6. Thus, a means-plus-function claim can be held invalid even if it passes the Court's "reasonable certainty" test.
Some of us who were around in 1993 when the patent in question was written will likely recall being told at very expensive seminars taught by some of the best in the business that M+F claims were the broadest way to claim something.
The specification did disclose a two-step algorithm. The fatal mistake was not making an argument for this algorithm in the lower court.
It may not have been a mistake - the patentee might have decided that claims limited to that algorithm would not have been infringed, and that they had to argue for a broader scope.

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