The Demise of the Functionality Doctrine in Design Patent Law

Perry J. Saidman*

The so-called doctrine of functionality arises in both design patent validity and infringement analyses. Broadly stated, the doctrine seeks to ensure that design patents do not monopolize that which should only be monopolized with utility patents.¹ In general, a utility patent protects utilitarian concepts embodied in a product, while a design patent protects only the specific visual embodiment of such concepts, i.e., the product’s appearance.²

In establishing the scope of a design patent during Markman claim construction,³ the functionality doctrine has proven to be unworkable—and is in fact unnecessary—as a precursor to determining infringement. In considering design patent validity, the so-called doctrine of functionality no longer plays any meaningful role.

On the infringement side, lower courts during Markman have rather consistently tried to “factor out” elements of the design that appear to be “functional,” a meaningless exercise that if pursued to its natural end will wind up with a claim to nothing.⁴ Recent decisions from the Federal Circuit have recognized this reality.⁵ Concerns about claimed utilitarian features that may comprise an industry standard or an essential component are taken into account during normal infringement analysis.

On the validity side, the lower courts remain somewhat confused as to how to determine whether a claimed design is impermissibly “functional.” Most courts lose sight of the fact that a design can both have utilitarian features and also have an overall appearance that is protectable. Currently, the go-to validity test for functionality is whether there are alternative designs to the one claimed in the design patent-in-suit that perform substantially the same function; if there are, the design patent is said not to monopolize that function.⁶ Recent Federal Circuit cases affirm the primacy of the alternative designs test, but omit analysis of the critically important and outcome-determinative word: “function.”⁷ This Essay will explore ramifications of the definition of “function.”

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© 2017 Perry J. Saidman. Individuals and nonprofit institutions may reproduce and distribute copies of this Article in any format at or below cost, for educational purposes, so long as each copy identifies the author, provides a citation to the Notre Dame Law Review, and includes this provision in the copyright notice.

*Principal, Saidman DesignLaw Group, LLC, a law firm in Silver Spring, Maryland, that specializes in legal issues involving designs and product configurations. The opinions expressed herein are those of the author only and do not necessarily represent those of any client of the firm.

1 Donald S. Chisum, Chisum on Patents § 23.034.

2 Id. § 23.01.

3 See generally Markman v. Westview Instruments Inc., 517 U.S. 370 (1996) (establishing that patent claims must be construed as a matter of law prior to a jury trial in an infringement case).

4 See, e.g., Richardson v. Stanley Works, Inc., 597 F.3d 1288, 1293 (Fed. Cir. 2010).

5 See, e.g., Sport Dimension, Inc. v. Coleman Co., 820 F.3d 1316 (Fed. Cir. 2016).

6 See, e.g., Best Lock Corp. v. Ilco Unican Corp., 94 F.3d 1563, 1566 (Fed. Cir. 1996).

7 See, e.g., Ethicon Endo-Surgery, Inc. v. Covidien, Inc., 796 F.3d 1312, 1329–30 (Fed. Cir. 2015).