Design Patents Explained

The core distinction: appearance vs. function

Every patent protects either function (utility patents) or appearance (design patents). This distinction is fundamental. A utility patent claims how an invention works — its mechanics, processes, and functional structures. A design patent claims the ornamental appearance of a manufactured article — its shape, surface decoration, or visual configuration.

A classic example: the Coca-Cola bottle. The bottle's shape is immediately recognizable. That distinctive contour is protected by a design patent (and eventually by trade dress). The bottle's internal structure and cap mechanism, if patented, would be utility patents. Same physical object; two entirely different categories of intellectual property.

A product can have both. The iPhone has thousands of utility patents covering its multi-touch technology, processor architecture, and software features. It also has design patents covering the specific visual appearance of the device — the rounded corners, the speaker placement, the button locations. Both categories can protect the same product simultaneously.

What a design patent covers

A design patent has a single claim: 'The ornamental design for [name of article], as shown and described.' The drawings ARE the claim. Unlike utility patents (where claim language defines scope), design patent scope is determined by comparing drawings.

Design patents can protect: the three-dimensional shape of a product (a car's body, a chair, a bottle), surface ornamentation on an article (a pattern on fabric, decoration on jewelry), the configuration of a user interface or icon (Apple has design patents on app icons), and the combination of elements that creates a distinctive visual impression.

The scope of a design patent is narrower than it might appear. Courts compare the patented design to accused designs element by element. Minor visual differences can distinguish an accused product from the patented design.

What a design patent cannot protect

Purely functional features cannot be protected by design patents. If the appearance of a product is dictated by its function — if it looks the way it does because it must look that way to work — a design patent cannot protect it. This is the functionality doctrine.

Example: the shape of a wrench is functional (it must fit bolt heads). You cannot get a design patent on a standard hex wrench. But a highly distinctive decorative grip, if the grip shape serves no functional purpose, could be design-patentable.

Hidden features — parts of a product not visible during normal use — cannot be protected by design patents. Courts have held that design patents protect only visible features. The internal electronics of a phone, even if their physical arrangement is distinctive, cannot be design-patented.

Abstract ideas, words, and concepts cannot be design-patented. The word 'Google' cannot be a design patent. The concept of a rounded rectangle cannot be a design patent. What can be patented is a specific, distinctive visual implementation.

The term and maintenance fees

Design patents in the US last 15 years from the grant date. This changed in 2015 (for applications filed after May 13, 2015) to align US law with international norms. Before 2015, design patents lasted 14 years.

Unlike utility patents, design patents require no maintenance fees. Once granted, a design patent remains in force for its full 15-year term without any additional payment to the USPTO. This makes design patents cheaper to maintain over their lifetime than utility patents.

The application process is typically faster and cheaper than utility patent prosecution. Most design patent applications are examined and granted within 18–24 months. There are no claim drafting issues as complex as utility patent prosecution, and office actions are less common.

How infringement is determined: the ordinary observer test

The test for design patent infringement is the 'ordinary observer' test, established in Gorham Manufacturing Co. v. White (1871) and refined in Egyptian Goddess Inc. v. Swisa Inc. (2008): infringement occurs when an ordinary observer, familiar with the prior art, would be deceived into thinking the accused design is the same as the patented design.

This is a holistic test, not a feature-by-feature comparison like utility patent infringement. The court asks: would an ordinary consumer, looking at the two designs, be confused about which is which? Would they likely buy one thinking it was the other?

The prior art matters in this analysis. When the prior art is very close to the patented design, small differences become more significant (because those differences are what distinguish the patent from prior art). When the prior art is far from the patented design, the same small differences may be less significant.

The Supreme Court's Samsung v. Apple (2016) ruling addressed an important design patent damages question: when a design patent is infringed, total profits from the entire article containing the design are available as damages — unless the infringing 'article of manufacture' is a component rather than the whole product. This ruling created important uncertainty about design patent damages calculations for complex products like smartphones.

Design patents in use: famous examples

Design patents vs. trade dress

Trade dress (protected under trademark law) can protect the distinctive visual appearance of a product — the same territory as design patents. The key difference: design patents expire after 15 years; trade dress protection can last indefinitely if the trade dress remains distinctive and in use.

Many companies use both. A product launches with design patent protection (stronger, more predictable). As the design patent life ends, the product's appearance may have become iconic enough to be protected as trade dress. Coca-Cola's bottle shape made this transition. The Reebok 'Freestyle' shoe sole design is trade-dress protected long after its design patents expired.

Trade dress protection requires proving that the appearance has become distinctive in the marketplace — consumers associate it with your company. Design patents require only filing before public disclosure and passing examination. Trade dress is generally harder to establish but can last forever.

Design vs. utility at a glance