When a Functional Claim Limitation is the “Essence of the Invention”

by Dennis Crouch

In re Jasinski (Fed. Cir. 2013)

Jasinski’s patent application is owned by IBM and directed to a method of testing computer memory devices. Application No. 10/906,508.  The USPTO examiner rejected the claims as anticipated and that rejected was affirmed by the USPTO’s internal review board.  On appeal here, the Federal Circuit reversed based upon a claim construction issue.

I have reproduced claim 1 below:

A method for verifying the accuracy of logical-to-physical mapping software designed for testing memory devices, said method comprising:

[a] providing a built-in self test (BIST) fail control function to generate multiple simulated memory fails at various predetermined locations within a
memory array of a memory device;

[b] testing said memory array via a memory tester;

[c] generating a bit fail map by said logical-to physical mapping software based on all memory fails indicated by said memory tester, wherein
said bit fail map indicates physical locations of all fail memory locations derived by said logical-to-physical mapping software; and

[d] comparing said fail memory locations derived by said logical-to-physical mapping software to said various predetermined memory locations to verify the accuracy of said logical-to-physical mapping software.

The USPTO refused to give patentable weight to either the preamble statement of purpose “verifying the accuracy” or the final functional clause indicating that the purpose of the final comparing step is “to verify the accuracy.”  Rather, the USPTO argued that those statements of intended purpose of a step rather than placing any actual limitation on the step itself. According to the USPTO, if the patentee wanted to include a verifying step then it could have done so by positively reciting that step. See Minton v. Nat’l Ass’n of Securities Dealers, Inc., 336 F.3d 1373 (Fed. Cir. 2003) (a whereby “clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited.”)

On appeal, the Federal Circuit agreed with the notion that a clause that merely indicate the purpose of a limitation does not add patentable weight.  However, the court disagreed the USPTO’s conclusion that the “to verify the accuracy” clause merely indicated the purpose of the step.  Rather, the court found that the “to verify the accuracy” clause refers to the “essence of the invention” and “provides the criteria by which the previously-recited comparing limitation is analyzed.” For this point, the court cited Vizio, Inc. v. Int’l Trade Comm’n, 605 F.3d 1330 (Fed. Cir. 2010) (“[T]he ‘for decoding’ language . . . is properly construed as a limitation, and not merely a statement of purpose or intended use for the invention, because ‘decoding’ is the essence or a fundamental characteristic of the claimed invention.”).

The decision by Judge Moore is important on several fronts:

1) Judge Moore is may well be the most claim-focused member of the Federal Circuit.  Yet, the opinion relies upon the “essence of the invention” to lead to its result rather than merely focusing on the claim language. At least on the academic side we continue to have a broad debate over whether the “cult of the claim” is appropriate.

2) From a practical perspective, this decision places additional power in the hands of patent applicants who reject the USPTO’s broadest reasonable interpretation of its patent claims.  Here, the PTO’s motivation was really that the applicant amend its claims to avoid ambiguity, but its approach was blocked by the court. Moving forward we will likely see continued growth in the use of functional claim language.

3) Functional claim language has been under attack since the Supreme Court rejected Samuel Morse’s broad Claim 8.  The patent act particularly allows for functional claim limitations under 35 U.S.C. 112(f), but that provision includes strict limits on the scope given to such limitations.  More recently, we have seen increased calls to take steps to limit the use of functional claim language.  As Prof Rantanen discussed yesterday, Mark Lemley has proposed that the court should begin interpreting functionally claimed elements as also being bound by 112(f).