1202.02(a)(ii) Purpose of Functionality Doctrine
The functionality doctrine, which prohibits registration of functional product features, is intended to encourage legitimate competition by maintaining a proper balance between trademark law and patent law. As the Supreme Court explained, in Qualitex Co. v. Jacobson Prods. Co., 514 U.S. 159, 164-165, 34 USPQ2d 1161, 1163 (1995):
The functionality doctrine prevents trademark law, which seeks to promote competition by protecting a firm’s reputation, from instead inhibiting legitimate competition by allowing a producer to control a useful product feature. It is the province of patent law, not trademark law, to encourage invention by granting inventors a monopoly over new product designs or functions for a limited time, 35 U.S.C. Sections 154, 173, after which competitors are free to use the innovation. If a product’s functional features could be used as trademarks, however, a monopoly over such features could be obtained without regard to whether they qualify as patents and could be extended forever (because trademarks may be renewed in perpetuity).
In other words, the functionality doctrine ensures that protection for utilitarian product features be properly sought through a limited-duration utility patent, and not through the potentially unlimited protection of a trademark registration. Upon expiration of a utility patent, the invention covered by the patent enters the public domain, and the functional features disclosed in the patent may then be copied by others – thus encouraging advances in product design and manufacture. In TrafFix Devices, Inc. v. Mktg. Displays, Inc., 532 U.S. 23, 34-35, 58 USPQ2d 1001, 1007 (2001), the Supreme Court reiterated this rationale, also noting that the functionality doctrine is not affected by evidence of acquired distinctiveness.
Thus, even when the evidence establishes that consumers have come to associate a functional product feature with a single source, trademark protection will not be granted in light of the public policy reasons stated. Id.