Ernie Ball Inc. v. Earvana, LLC – Claim Drafting Lessons

by Ryan Alley on January 30, 2013

in -, CAFC District Court appeals

Case No. 2012-1276 (Newman, Lourie, O’Malley) (nonprecedential)

Sine WaveContinuing with another quirky nonprecedential case, Ernie Ball, Inc. v. Earvana, LLC offers up a number of peculiar results before the Federal Circuit. The opinion is remarkable for the court’s willingness to all but litigate the case for the parties, holding claims invalid as indefinite on appeal when the issue was not specifically argued or passed upon at the district court. Despite the procedural hijinks, the facts and discussion here provide some warnings for negative claim limitations and failure to discuss claim terms in the specification.

The technology at issue was fairly easy to grasp – mechanisms for proper guitar tuning. Ernie Ball, a guitar accessories supplier, owned US Patent 6,433,264 directed to a fixed compensated nut at the top of the guitar neck, above the frets. Each string passed through distinct intonation portions in the nut, and each intonation portion was sized with a unique depth. This had the critical effect of imparting a distinct length to each string passing therethrough, allowing better tuning. The problem during the ‘264 patent’s prosecution, however, was that a previous patent to LoJacono described an adjustable nut with mechanisms that changed the length of each string. So the patentee amended the claims to include the following bolded portion, which resulted in allowance:

1. A compensated nut for a stringed instrument, the stringed instrument having one or more strings, a body and a neck, the nut comprising:
an elongated body having a length sufficient to extend across at least a portion of the neck of the stringed instrument; and
one or more fixed intonation portions on a front side of the elongated body, the intonation portions having different dimensions according to the desired pitch compensation for each string and being configured such that a line extending through the one or more fixed intonation portions does not form a sinusoidal arc.

LoJacono AA vs 264 Patent NutLoJacono specifically described its nut as forming a “sinusoidal configuration,” as shown by line A-A in the featured drawing (right-top). The ‘264 patent disclosed something different (right-bottom), and, in its background, identified LoJacono as having a sinusoidal configuration and other undesireable features. The Examiner was satisfied that the added “does not form a sinusoidal arc” limitation distinguished over LoJacono’s configuration and allowed the ‘264 patent to issue.

Ernie Ball, having procured the ‘264 patent, turned around and sued the owner of the LoJacono patent, Earvana, for infringement. The district court proceedings were a mess. Earvana lodged dozens of affirmative defenses, including a generic “§ 112″ invalidity defense. The case was passed between multiple judges, ultimately resulting in a holding that the claims were valid and infringed. The district court never addressed indefiniteness when considering claim validity. Earvana appealed to the 9th Circuit, who transferred the case to the Federal Circuit.

The arguments on appeal were just as messy. The Federal Circuit noted that the parties had not identified individual claims in their arguments of claim construction, infringement, or validity. Lacking specific arguments, the court took claim 1, above, as representative and began de novo claim construction. Focusing on the “sinusoidal” language, the panel noted that the term was used in the ‘264 patent only to reference LoJacono, which in turn did not set out any specific definition. The court thus held that the plain language controlled, which gave “sinusoidal” a strict mathematical definition:

we conclude that one of ordinary skill in the art reading the ’264 patent in view of the relevant intrinsic record would rely on the term’s ordinary meaning and would therefore understand the term “sinusoidal,” as used in claim 1, to indicate “a configuration that strictly conforms to the shape of a sine wave or arc.”

Then the panel, “having examined the ’264 patent, its claims, and its prosecution history in construing the contested claim term” invalidated the claims under § 112, second paragraph as a matter of law. The court justified this sua sponte exercise of power based on Earvana’s generic challenge under § 112 and the court’s role as claim construer:

While Earvana has not specifically pointed to the definiteness requirement of § 112, ¶ 2, it did challenge the asserted claims as invalid under § 112 in the district court, and it maintains that assertion on appeal. The definiteness requirement “is drawn from the court’s performance of its duty as the construer of patent claims.” Atmel Corp. v. Info. Storage Devices, 198 F.3d 1374, 1378 (Fed. Cir. 1999); see also Eplus, Inc. v. Lawson Software, Inc., 700 F.3d 509 (Fed. Cir. 2012) (“[I]ndefiniteness is a question of law and in effect part of claim construction.”). “The reviewing tribunal must determine whether a person experienced in the field of the invention would understand the scope of the claim when read in light of the specification.” Energizer Holdings, Inc. v. Int’l Trade Comm’n, 435 F.3d 1366, 1369 (Fed. Cir. 2006). We therefore address definiteness as a pure legal question [under] our “duty as the construer of patent claims.”

Lost in Curves as Archimedes OnceThe claim term here – “a line extending through the one or more fixed intonation portions does not form a sinusoidal arc” – did not sufficiently clearly delineate (hah!) what must be done to infringe the claim. The court observed that, with proper frequency adjustment, any set of points could be made to fall on a sinusoidal arc. The court even offered an illustration, using actual points from an embodiment of the ‘263 patent to draw one line meeting the claim (top left) and another line not meeting the claim (bottom left) for the exact same points. Thus, what fell on a sinusoidal arc depended on what line the construer drew.

Subjective claim elements are not fatal, but the specification has to offer some constraining standard. Based on the scant usage of the term in the ‘264 patent and little guidance from the referenced LoJacono patent, the claims were invalid:

“When faced with a purely subjective phrase . . . a court must determine whether the patent’s specification supplies some standard for measuring the scope of the phrase.” Datamize, LLC v. Plumtree Software, Inc., 417 F.3d 1342, 1351 (Fed. Cir. 2005). Here, the ’264 patent offers no objective way to discern the appropriate (sinusoidal or non-sinusoidal) line extending through the intonation portions of a nut for purposes of determining infringement. As in Datamize, claim 1 thus “fails to delineate the scope of the invention using language that adequately notifies the public of the patentee’s right to exclude.” Id. at 1353. Accordingly, claim 1 is invalid for failure to satisfy § 112, ¶ 2.


Lessons: Write meaningful dependent claims and vary usage among independent claims. Especially with regard to a feature an applicant knows or suspects to be a point of novelty. Not only does this give an applicant more bites at the apple in finding allowable subject matter before the examiner, but it also creates backup positions for definiteness (and enablement, and obviousness) at litigation. The patentee in Ernie Ball v. Earvana would have avoided the Federal Circuit’s grinding axe by doing it. The ‘264 patent applicant knew the intonation portion sizing was the distinguishing claim feature over LoJacono and could have easily elaborated on the intonation portions by, for example, setting out relative intonation portion positions or even specific lengths for the portions in dependent claims. Or the applicant could have written a new independent claim stating a line smoothly connecting the intonation portions included unequal, plural peaks and/or troughs. These further refinements would likely have survived the court’s line drawing.

This goes doubly when reciting 1) negative limitations or 2) exotic phrases or potential terms of art not found in the specification. Both of these things can have unforeseen scope, which can avoid full testing tested during prosecution and go on to open up a world of potential invalidity or narrowing down the line. While I think negative limitations and specific terms have their places (especially when thoughtfully treated in the specification, more on that in the next paragraph), many negative limitations and fancy words can be expressed in much simpler, positive terms whose scope does not risk indefiniteness, invalidity, narrow construction, and/or a new matter rejection. At the very least, give yourself some further definition in dependent claims or use other independent claims without negative or unique terms. As seen in Ernie Ball, the court was fine not only giving the rather flowery “sinusoidal arc” a very stingy, strictly mathematical construction, but also invalidating the claim for using it in a negative sense that deprived the claim of much meaning.

Lastly, Ernie Ball reminds that some of the above pitfalls can be relieved by clear usage in the specification, which can provide definiteness to subjective, relative, and/or protean claim terms. Of course, one patent attorney’s “clear use of a term in the specification” may be another’s “unduly limiting usage in the specification.” I’m a fan of taking a middle approach by including all initially-drafted claim terms at least once in the specification, preferably as a short and broad introduction to the disclosed subject matter, and then describing example embodiments in detail with other terms that show the breadth of the initially-introduced claim term. This provides more room both for amending claims and for pushing back against an indefiniteness rejection that overlooks clear treatment of a claim term in the specification. Unfortunately, the specification’s ability to provide definiteness to every claim term fades after several years of prosecution over close prior art that has required multiple claim amendments into implicit and narrow subject matter that wasn’t initially contemplated as the patentable feature. In such a case bear in mind the above suggested lessons. The ‘264 patent fell into this unfortunate prosecution pattern; the application went through rounds of prosecution without any progress over close prior art. The dispute over patentability finally got sharpened down to one specific feature in a primary reference, and the claims were amended to distinguish that feature. After years of dealing with an application, it can be tempting to simply amend in a new negative limitation, say, “wherein [X] is not the [prior art X],” and be done with the case. But as the Ernie Ball patentee learned, without a prescient specification detailed description, this approach alone can be perilous.

Comment: I think the panel really stretched to make a statement on indefiniteness here. There were easier avenues to invalidate the claims, and the opinion takes a decidedly new approach to indefiniteness. As for other invalidity avenues, I think the court could have easily entertained invalidation over the LoJacono reference, which was actually argued by the parties. After concluding that the “sinusoidal arc” limitation did not meaningfully limit the claim and observing that LoJacono disclosed nut arrangements that did not meet a strict mathematical sinusoidal curve, I would think obviousness would not be but a couple paragraphs away.

As for this being a new approach, the Federal Circuit has held that § 112 indefiniteness applies only when a claim is insolubly ambiguous and is not amendable to construction. Yet the Ernie Ball panel easily (albeit broadly) construed the claim here. The Federal Circuit has also been stricter on refusing to consider indefiniteness arguments that are not very specifically preserved for appeal and not addressed by the district court below. Indeed, panel member Judge Newman has previously voiced opposition to lodging new § 112, second paragraph rejections on appeal. Yet the Ernie Ball panel readily took up indefiniteness as a legal issue of claim construction without any party ever making competent arguments to this effect.

As to the merits of indefiniteness, the court seems to adopt a very strange interpretation of a “line” that “does not form a sinusoidal arc” in order to arrive at its conclusion that the limitation has insolubly ambiguous meaning. In its line drawing, the court seems to interpret the phrase as requiring points that only fall on a sinusoidal arc. To me, the claim language “form” requires something else, like points that at least define the maxima and minima and some curvature. The ‘264 example embodiment points didn’t define consistent maxima like a sinusoid. Lastly, the ‘264 patent’s background use of “sinusoidal” in connection with LoJacono, which also uses the term, seems to indicate that the simple arcs of LoJacono would fall within this term, and the more complex lines of the ‘264 patent, with a local maxima, would not. I don’t see why a skilled artisan would have a problem differentiating between these two different shapes.

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