By Michael Borella —

The patent statute requires that, to be patentable, the subject matter of an invention must be at least one of a process, machine, article of manufacture, or composition of matter.  It is hard to find examples of things that do not fall into these broad categories, though signals in motion and data at rest are two.  The former has been well-litigated at this point and it is accepted that various forms of computer-readable medium (CRM) claims must recite that the medium is non-transitory.  Consider the 2007 Federal Circuit decision of In re Nuijten as the standard bearer in this regard.

Nonetheless, disputes over the interpretation of CRM language do pop up from time to time, as was the situation in this case.

Sequoia asserted U.S. Patent No. 6,718,436 against Dell and several other companies (most notably, Red Hat, which is a subsidiary of IBM) in the District of Delaware.  The parties butted heads over claim construction issues in district court with Sequoia coming up on the losing end.  Thus, they stipulated non-infringement under this construction.  The District Court also found that claims 8-10 were ineligible under § 101 due to construction of the term "computer-readable recording medium" to include transitory media.  Sequoia appealed.

Claim 8 of the '436 patent reads:

8.    A computer-readable recording medium storing instructions for executing a method for managing a logical volume in order to support dynamic online resizing and minimizing a size of metadata, said method comprising the steps of:
    a) creating the logical volume by gathering disk partitions in response to a request for creating the logical volume in a physical storage space;
    b) generating the metadata including information of the logical volume and the disk partitions forming the logical volume and storing it the metadata to the disk partitions forming the logical volume;
    c) dynamically resizing the logical volume in response to a request for resizing, and modifying the metadata on the disk partitions forming the logical volume; and
    d) calculating and returning a physical address corresponding to a logical address of the logical volume by using mapping information of the metadata containing information of the physical address corresponding to the logical address;
    wherein the metadata includes,
        a disk partition table containing information of a disk partition in which the metadata is stored;
        a logical volume table for maintaining the information of the logical volume by storing duplicated information of the logical volume onto all disk partitions of the logical volume;
        an extent allocation table for indicating whether each extent in the disk partition is used or not used; and
        a mapping table for maintaining a mapping information for a physical address space corresponding to a logical address space which is a continuous address space equal in size of storage space to an entirety of said logical volume.

As noted, the main part of the § 101 dispute was over the interpretation of the term "computer-readable recording medium."  The Federal Circuit immediately noted that this term explicitly recites a "recording medium storing instructions" and that "a person of ordinary skill would not understand transitory signals, such as carrier waves, to record or store instructions in memory systems."  This understanding is supported by other claim elements, such as "creating the logical volume in a physical storage space" and "storing [sic] the metadata to the disk partitions forming the logical volume."  All of this establishes that the computer-readable recording medium of claim 8 does not encompass non-persistent or transient storage.

The Court found further support for its position in the specification.  Particularly, the specification provides several examples of hardware-only computer-readable media including RAM, CDROM, and various types of disk drives.

One of the defendants, Red Hat, argued that the specification does not exclude transitory media.  But the Court pushed back, noting that the claim itself recites a "storage medium" and that Red Hat's proposed interpretation would contradict the teachings of the specification and render the invention inoperable.

The Court also found that Red Hat's expert's testimony was "inconsistent with the intrinsic evidence and also based on different express definitions of CRM in patent specifications directed to different inventions."  Notably, the expert looked to 34 other patent applications to help define the claim term.  The Court was not amused:

This evidence merely shows that in thirty-four other specifications, the inventors chose to be their own lexicographers and expressly defined CRM or like terms to include transitory media.  The inventors here chose otherwise.  That other inventors chose to be their own lexicographers and define CRM to include transitory signals does not demonstrate what CRM means in the context of the '436 patent.  Nor does it establish the plain and ordinary meaning of the claim term "computer-readable recording medium for storing."

In a similar manner, Red Hat also relied on the Court's decision in Mentor Graphics Corp. v. EVE-USA, Inc., where the Court found that a claimed "computer readable medium" included transitory signals.  But this conclusion was based on that specification expressly including carrier waves in its definition of the term.  Accordingly, the Court found that how a term is defined other patents and applications cannot be used to contradict how it is defined in the specification at hand.  Specifically, the Court wrote "[s]imply put, extrinsic evidence of what other inventors chose to do cannot surmount the intrinsic evidence of what the inventors chose here; context is key in claim construction."  Thus, the Court discounted the testimony of Red Hat's expert and the relevance of these extrinsic documents.

Finally, Red Hat pointed to the USPTO's 2010 memo on computer-readable medium claims, alleging that it establishes that the term in question should be interpreted broadly enough to include transitory media.  But, as the Court pointed out, this memo merely states that the broadest reasonable interpretation of a claim during prosecution may result in claims being interpreted to cover transitory media.  However, this does not provide the plain and ordinary meaning of the term to be used in litigation, nor does it mean that there is a presumption that claim 8 reads on transitory media.

Given all of this, the Court concluded that the District Court erred, and reversed the finding of invalidity under § 101.

A practice note from all of this is that you should explicitly recite in your CRM claims language that clearly establishes that the CRM is non-transitory.  This does not need to be the exact words "non-transitory" but however your language is defined in the specification should make that point clear and unambiguous.

Unlike the claimed invention, this victory for Sequoia turned out to be transitory — it lost on other claim construction issues and the Court ultimately affirmed the determination of non-infringement.

Sequoia Technology LLC v. Dell Inc. (Fed. Cir. 2023)
Panel: Circuit Judges Lourie, Dyk, and Stoll
Opinion by Circuit Judge Stoll