Introduction: One Product, Two Kinds of Patent

A flat asphalt roofing shingle is about as humble an object as the patent system ever sees. And yet, in the late 1990s, two different United States patents -- one a utility patent, one a design patent -- protected color striations printed on the back of such a shingle. The striations did something clever: they tricked the eye into reading a flat surface as three-dimensional, giving a cheap shingle the rich, shadowed look of an expensive one. The utility patent protected the mechanism of the illusion. The design patent protected the appearance the illusion produced. Neither patent swallowed the other, and the Federal Circuit had no trouble letting both stand. See Elk Corp. of Dallas v. GAF Building Materials Corp., 168 F.3d 28 (Fed. Cir. 1999); Elk Corp. of Dallas v. GAF Bldg. Materials Corp., 45 U.S.P.Q.2d 1011 (N.D. Tex. 1997) (the utility and design patents at issue were U.S. Patent No. 5,369,929 and U.S. Design Patent No. D344,144). That unassuming shingle is a perfect parable for the subject of this article: a single object can carry two completely different kinds of patent, protecting two completely different things, at the same time -- and often it should.

Picture a more modern example. A company we will call Acme Corp. has invented a new water bottle. The bottle has a never-before-seen internal valve that lets you drink without tilting it, and it also has a sleek, sculpted, instantly recognizable silhouette that a shopper can spot on a store shelf from twenty feet away. Acme has, in a single object, two distinct kinds of innovation: a new function (the valve) and a new appearance (the silhouette). The patent system offers two different tools to protect those two kinds of innovation, and a sophisticated strategy will deploy both at once.

The first tool is the utility patent, which protects the way an invention works -- its function, structure, and method of operation. The second is the design patent, which protects the way an article of manufacture looks -- its ornamental appearance. These are not interchangeable. They protect different things, are examined under different standards, expire at different times, are infringed under different tests, and yield different remedies. Yet because a single physical object frequently embodies both new function and new appearance, the two regimes constantly meet at the surface of the same product. That meeting place is the subject of this article.

For inventors and the lawyers who advise them, the intersection raises a series of practical questions. When can one article carry both a utility patent and a design patent? Is there ever a problem with holding both? What is the line between a protectable ornamental design and an unprotectable functional one? If a competitor copies the product, which patent gives the better remedy? And does obtaining both patents risk an "improper extension" of the patent monopoly that the doctrine of double patenting is designed to prevent?

This article answers those questions in depth. It is written so that a judge, a patent practitioner, and an interested layperson can all follow it; every term of art is explained in plain language the first time it appears, and a detailed worked example near the end ties the doctrines together for a single hypothetical product. Throughout, it cross-references the firm's companion articles, including a plain-English foundation in patent basics and the essentials of utility patents, the LKQ decision and its overhaul of design-patent obviousness, the evolution of design-patent functionality doctrine, the relationship between design patents and trade dress for product configurations, the mechanics of overcoming obviousness rejections under Section 103, the litigation of design patents, and a plain-English set of answers to common USPTO patent questions.

Part One: Two Statutes, Two Kinds of Protection

The Utility Patent (35 U.S.C. Section 101)

A utility patent protects what an invention does. The statutory gateway is 35 U.S.C. Section 101, which provides that "[w]hoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor." A utility patent thus covers functional subject matter: the structure of a machine, the steps of a method, the chemistry of a composition, the architecture of a device. To be valid, the claimed invention must be useful (Section 101), novel -- meaning new and not already in the prior art (Section 102), and nonobvious -- meaning that the differences between the invention and the prior art would not have been obvious to a person of ordinary skill in the art at the time (Section 103). It must also satisfy the disclosure requirements of Section 112, which demand a written description, an enabling disclosure that teaches the public how to make and use the invention, definiteness, and (under pre-AIA law for older patents) the inventor's best mode. The firm's overview of utility patent basics walks through these requirements in detail.

The term of a utility patent is twenty years from the earliest effective non-provisional filing date (35 U.S.C. Section 154(a)(2)), a measure adopted when the United States moved from the older seventeen-years-from-issuance rule under the Uruguay Round Agreements Act (URAA). Because the clock runs from filing, time spent in prosecution at the U.S. Patent and Trademark Office (USPTO) eats into the enforceable term -- which is why utility patents are eligible for patent term adjustment (PTA) to compensate for certain examination delays, and why they require three scheduled maintenance fees to stay alive (35 U.S.C. Section 41(b)). A utility patent typically contains multiple claims, written as text, each defining the metes and bounds of one version of the invention with precise verbal language (35 U.S.C. Section 112(b); 37 C.F.R. Section 1.75).

The Design Patent (35 U.S.C. Section 171)

A design patent protects what an article of manufacture looks like. The statutory gateway is 35 U.S.C. Section 171, which provides that "[w]hoever invents any new, original and ornamental design for an article of manufacture may obtain a patent therefor." The operative word is ornamental: a design patent protects the non-functional, visual, aesthetic characteristics of an article -- its shape, configuration, surface ornamentation, or some combination of those features -- as applied to a particular product. Automotive Body Parts Ass'n v. Ford Global Technologies, LLC, 930 F.3d 1314, 1318 (Fed. Cir. 2019). Design patents must be new (novel) and nonobvious, just like utility patents, but they protect appearance rather than function, and a design claim is tethered to the article of manufacture identified in the claim; it cannot cover a design "in the abstract." In re SurgiSil, L.L.P., 14 F.4th 1380, 1382 (Fed. Cir. 2021).

That tethering is more consequential than it sounds. In Curver Luxembourg, SARL v. Home Expressions Inc., 938 F.3d 1334 (Fed. Cir. 2019), the patentee owned a design patent claiming an overlapping "Y" weave pattern for a "chair" -- but the patent's figures showed only the pattern, never a chair. When the patentee sued a maker of baskets bearing a similar weave, the Federal Circuit held that the claim language confined the patent to chairs, so the baskets could not infringe. The lesson is that for a design patent "the law has never allowed . . . a design patent for a surface ornamentation in the abstract"; the article of manufacture matters, and how the applicant identifies it during prosecution can quietly narrow -- or accidentally gut -- the patent's reach. Curver, 938 F.3d at 1336-40.

The term of a design patent is fifteen years from the date the patent issues for applications filed on or after May 13, 2015 (35 U.S.C. Section 173); design patents issuing on applications filed before that date carry the older fourteen-year term. The fifteen-year term arrived with U.S. accession to the Hague Agreement Concerning the International Registration of Industrial Designs, which lets applicants file a single international application designating multiple member countries. Three features of the design-patent term deserve emphasis. First, the clock runs from issuance, not filing, so prosecution delay does not shorten the enforceable life of the patent -- and, correspondingly, design patents are not eligible for patent term adjustment. Second, design patents require no maintenance fees (MPEP Section 1502), so unlike utility patents they cannot be lost to a missed payment. Third, a design patent contains exactly one claim, written in a fixed statutory format -- "The ornamental design for [the article] as shown [and described]" -- and the real content of that claim lives in the drawings. The drawings, not the words, define the protected design. 37 C.F.R. Section 1.153(a); MPEP Section 1503.01.

Two Quietly Important Application Differences

Beyond term and claim format, two filing-side differences trip up the unwary and matter at the intersection. A utility applicant may anchor priority to a provisional application filed up to a year earlier (35 U.S.C. Section 111(b)); a design applicant may not claim provisional benefit at all (37 C.F.R. Section 1.53(c)(4)). And the window for claiming foreign priority is twelve months for a utility application but only six months for a design application (35 U.S.C. Section 172; 37 C.F.R. Section 1.55(b)). A company that wants both kinds of protection on a single product, and wants to preserve foreign rights, must therefore calendar the design deadline tightly -- the design priority clock runs out twice as fast.

A Side-by-Side Comparison

The two regimes can be compared along several axes, and keeping these distinctions straight is the foundation of everything that follows:

  • Subject matter. Utility patents protect function, structure, and method (Section 101). Design patents protect non-functional, ornamental appearance applied to an article of manufacture (Section 171).
  • Term. Utility: twenty years from filing, with maintenance fees. Design: fifteen years from issuance (post-2015 filings), no maintenance fees.
  • The claim. Utility patents have multiple textual claims. Design patents have a single claim defined by drawings.
  • Disclosure. Utility patents require a detailed written description and enabling disclosure under Section 112. Design patents require drawings showing enough views to disclose the complete claimed design, with a description sufficient to let an average designer make it.
  • Patent term adjustment. Available for utility patents; not available for design patents.
  • Examination perspective. For utility novelty, obviousness, and disclosure, the lens is a person of ordinary skill in the art. For design obviousness and disclosure, the relevant person is an ordinarily skilled designer of articles of the type involved; design novelty is judged through the eyes of an ordinary observer. MPEP Sections 1504.03, 2141.03.
  • Infringement test. Utility infringement turns on claim construction and a limitation-by-limitation comparison. Design infringement turns on the visual "ordinary observer" test. (Part Five.)
  • Damages. Both regimes allow lost profits and a reasonable royalty, but design patents add the total-profit remedy of 35 U.S.C. Section 289. (Part Six.)

A reader who wants a deeper treatment of how design patents compare to a third regime -- federal trade dress, which protects product appearance under trademark law once it has acquired source-identifying significance -- should consult the firm's article on design patents versus trade dress protection for product configurations. The present article focuses on the two patent regimes and their interaction.

Part Two: When One Article Can Carry Both

There Is No Per Se Bar

The most important threshold point is that there is no per se prohibition against obtaining both a design patent and a utility patent on the same physical article. This principle is old and well settled. A device patentable as a manufacture may also embody a patentable design, and courts have repeatedly affirmed that a design patent and a utility patent may issue on the same physical structure. The two patents protect different things -- the utility patent the function, the design patent the appearance -- and the patent statute contemplates that a single object may possess both new function and new appearance. Sections 101 and 171 establish parallel, independent paths to protection, and an applicant is free to walk both. See, e.g., Liqui-Box Corp. v. Reid Valve Co., 16 U.S.P.Q.2d 1848, 1855 (W.D. Pa. 1990) (six-gallon rectangular polycarbonate bottle); In re Dubois, 262 F.2d 88 (C.C.P.A. 1958); Clark Equipment Co. v. Keller, 197 U.S.P.Q. 83 (D.N.D. 1976), aff'd in part, rev'd in part on other grounds, 570 F.2d 778 (8th Cir. 1978). Practical Law's own Design and Utility Patents Key Differences Chart puts the point crisply: "A design patent can cover [the] same product as a utility patent but protects distinct aspects of it." For the classic scholarly treatments, see Mesley, Design and Mechanical Patents Relating to the Same Subject Matter, 44 J. Pat. Off. Soc'y 309 (1962), and Gambrell, Mechanical and Design Inventions: Double Patenting Rejections and the Doctrine of Election, 45 N.Y.U. L. Rev. 441 (1970).

The roofing-shingle case in the introduction is the textbook illustration. Elk Corp., 168 F.3d 28. Neither patent swallowed the other, because each claimed a genuinely different facet of the same product -- one the engineering of the depth illusion, the other the look it created.

Typical Candidates for Dual Protection

Many everyday products are natural candidates for concurrent protection because they combine genuine functional novelty with genuine ornamental novelty. Consider:

  • An ergonomic tool handle that grips better than anything on the market (a function worth a utility patent) and also has a distinctive sculpted shape consumers recognize as the brand's (an appearance worth a design patent).
  • A consumer-electronics housing with a novel internal cooling architecture (utility) and a clean, instantly identifiable exterior form (design).
  • A beverage-container closure with an innovative one-handed sealing mechanism (utility) and a unique cap silhouette (design).
  • A piece of furniture with a new structural joint that lets it fold flat (utility) and a striking, original visual profile (design).
  • A software application's interface, where the underlying method of presenting and manipulating data may be utility-eligible, while the specific look of the on-screen graphical user interface and animated icons may be design-eligible as a design applied to an article of manufacture (a display screen). The USPTO treats a computer-generated icon shown on a display as meeting the article-of-manufacture requirement. MPEP Section 1504.01(a). Practitioners advising app developers should also review the firm's guidance on protecting a mobile app through a layered IP strategy.

In each of these cases, the two patents are aimed at different targets. The trouble -- the double-patenting trouble examined in Part Four -- arises only when the same feature carries both the novel function and the novel appearance, so that the two patents are really claiming the same thing twice.

Cross-Application of Prior Art

A point that surprises many newcomers: although utility and design patents have different statutory bases and different validity standards, there is no parallel partition when it comes to prior art. A design patent can be cited as prior art against a utility application, and a utility patent can be cited against a design application. In re Aslanian, 590 F.2d 911 (C.C.P.A. 1979). The prior-art universe does not divide neatly into "ornamental" and "functional" boxes; an examiner searching for what was already known about a product may pull references of either type. This matters in two ways. First, a freedom-to-operate or patentability search should sweep across both patent types, not just the one the applicant happens to be seeking; the firm's article on conducting a freedom-to-operate analysis for new products develops this point. Second, it sets up the double-patenting analysis, because the same cross-type comparison that governs prior art also governs whether one of an applicant's own patents can be used as a double-patenting reference against the other.

Part Three: The Functionality Bar -- Ornamental Versus Dictated-by-Function

Before a product can carry a design patent at all, its design must clear the functionality bar. This is the doctrine that separates a protectable ornamental design from an unprotectable functional configuration, and it sits at the heart of the design-utility intersection because it is precisely the doctrine that keeps the design-patent system from being used to monopolize function -- something only a utility patent is supposed to do, and only for a shorter, function-tested term.

"Primarily Ornamental" Versus "Primarily Functional"

The statute requires that a design be ornamental (Section 171). The Federal Circuit has translated this into a "primarily ornamental versus primarily functional" inquiry: a design is eligible for protection only if it is primarily ornamental and is invalid if it is primarily dictated by function. PHG Technologies, LLC v. St. John Cos., 469 F.3d 1361, 1366 (Fed. Cir. 2006); Ethicon Endo-Surgery, Inc. v. Covidien, Inc., 796 F.3d 1312, 1328 (Fed. Cir. 2015). The classic formulation is that to be ornamental the design must have been "created for the purpose of ornamenting" the article rather than "dictated by" the article's function. In re Carletti, 328 F.2d 1020, 1022 (C.C.P.A. 1964).

Crucially, the test is not whether the design has any function -- almost every product design does -- but whether the appearance is dictated by function. A pleasing shape that also happens to work well is still protectable, "provided that the design per se is pleasing, attractive, novel, useful, and unobvious," because "it is the design that is patented, not the mechanism dressed in the design." J.G. Furniture Co. v. Litton Business Systems, Inc., 436 F. Supp. 380, 388 (S.D.N.Y. 1977). The fact that a design's shape is compatible with a functional objective does not by itself defeat patentability, at least where there are "a myriad of alternatives and variables" available to achieve the same function. John O. Butler Co. v. Block Drug Co., 620 F. Supp. 771 (N.D. Ill. 1985); Bergstrom v. Sears, Roebuck & Co., 496 F. Supp. 476, 489 (D. Minn. 1980).

The "Alternative Designs" Signal

The single most important piece of evidence in the functionality analysis is the existence of alternative designs that achieve the same function. If a manufacturer could have built a fully functional version of the product using any number of different shapes, then the particular shape chosen is more likely a matter of ornamental choice than functional necessity -- and is therefore protectable. Conversely, if the function essentially requires the claimed shape, the design is dictated by function and unprotectable. Automotive Body Parts Ass'n, 930 F.3d at 1319; Sport Dimension, Inc. v. Coleman Co., 820 F.3d 1316, 1320-22 (Fed. Cir. 2016).

The availability of alternatives is a strong signal but not, standing alone, dispositive. The Federal Circuit weighs several factors bearing on whether a design is dictated by function: whether the protected design represents the best design; whether alternative designs would adversely affect the utility of the article; whether there are any concomitant utility patents; whether the patentee advertised particular features as having specific utility; and whether there are elements in the design clearly not dictated by function. PHG Technologies, 469 F.3d at 1366. The third factor is the one to watch when you hold both kinds of patent on the same product: the existence of a concomitant utility patent describing a feature as functional is admissible evidence that the same feature's appearance is functional, too. A poorly coordinated dual-filing strategy can therefore hand an accused infringer a road map to the design patent's invalidity. Coordinate the two specifications so the utility patent does not tout as functional the very lines the design patent claims as ornamental.

A subtle but important refinement: the mere aesthetic appeal of a design to consumers does not make it "functional." Some defendants have argued an "aesthetic functionality" theory -- that a design is functional because its attractiveness drives sales. The Federal Circuit has rejected importing that trademark-law concept into design-patent law: that consumers like how a design looks is the very thing design patents are meant to protect, not a reason to deny protection. Readers who want the full doctrinal history of how this once-muddled area was clarified should turn to the firm's dedicated treatment in the evolution of design-patent functionality.

Why This Matters for Concurrent Protection

The functionality bar is the conceptual hinge of this entire subject. When Acme seeks both a utility patent on its water-bottle valve and a design patent on its silhouette, the functionality analysis asks whether the silhouette is ornamental (protectable by design patent) or merely the inevitable consequence of the valve's mechanics (in which case the appearance is dictated by function and only the utility patent should issue). The cleanest case for dual protection is the one in which the functional innovation and the ornamental innovation reside in different features, or in which the same outward shape could have housed the same function in countless other forms. The hardest case -- and the one that triggers double-patenting concerns -- is the one in which the very feature that produces the novel appearance is the very feature that produces the novel function.

Part Four: Double Patenting Across Design and Utility Patents

What Double Patenting Is and Why It Exists

Double patenting is the doctrine that prevents an inventor from obtaining two patents for, in effect, the same invention, and thereby unjustly extending the period of exclusivity beyond what a single patent term allows or improperly forcing the public to defend multiple infringement suits over a single inventive concept. AbbVie Inc. v. Mathilda & Terence Kennedy Institute of Rheumatology Trust, 764 F.3d 1366, 1372 (Fed. Cir. 2014). The doctrine applies to utility, design, and plant patents alike, and it is evaluated claim by claim, comparing the challenged claims against the claims of an available reference patent; invalidating one claim does not automatically invalidate the rest of the patent. 35 U.S.C. Sections 101, 161, 171, 282(a); Ortho Pharm. Corp. v. Smith, 959 F.2d 936, 942 (Fed. Cir. 1992); MPEP Sections 801, 804. There are two species:

1. Statutory (same-invention) double patenting. Rooted in the word "a" patent in Sections 101, 161, and 171, this prohibits two patents claiming the identical invention -- claims of the same scope, though not necessarily identical words. In re Vogel, 422 F.2d 438, 441 (C.C.P.A. 1970); Suffolk Co. v. Hayden, 70 U.S. 315, 319 (1865). It is rarely the live issue at the design-utility intersection, because a design claim (drawings) and a utility claim (text) almost never have literally the same scope. Critically, statutory double patenting admits of no cure by terminal disclaimer.

2. Obviousness-type double patenting (ODP). This judicially created, equitable doctrine does most of the work. ODP prohibits a second patent whose claims, though not identical to the first patent's claims, are not patentably distinct from them -- meaning the second claims are either anticipated by or obvious in light of the first. The purpose is to prevent the "unjustified timewise extension of the right to exclude" and "multiple infringement suits by . . . different assignees asserting essentially the same patentable invention." In re Hubbell, 709 F.3d 1140, 1145 (Fed. Cir. 2013); In re Longi, 759 F.2d 887, 892 (Fed. Cir. 1985). The ODP comparison borrows the prior-art frameworks for anticipation and obviousness, with one wrinkle: it is generally measured against the claims of the reference patent, with use of that patent's specification "strictly limited." In re Kaplan, 789 F.2d 1574, 1579 (Fed. Cir. 1986); AbbVie, 764 F.3d at 1380. As in ordinary obviousness, objective evidence of patentability (commercial success, copying, long-felt need) can rebut a prima facie ODP case. Eli Lilly & Co. v. Teva Parenteral Medicines, Inc., 689 F.3d 1368, 1381 (Fed. Cir. 2012). Readers seeking the general mechanics -- the Graham v. John Deere factual inquiries that ODP borrows -- will find them in the firm's guide to overcoming obviousness rejections under Section 103.

The Cross-Type Problem

ODP can arise across patent types. A design patent can serve as the double-patenting reference against a utility patent, and vice versa. In re Thorington, 418 F.2d 528, 536 (C.C.P.A. 1969); MPEP Section 804(II)(B)(4). The same cross-application of references that governs prior art (Part Two) governs ODP. So the question becomes: when are a company's own design and utility patents on the same product close enough that holding both is impermissible double patenting?

The historical answer focused on whether the design and utility patents claimed "separate, distinct patentable inventions." The mere fact that a utility patent's specification illustrated its claims using a design that happened to be the subject of a design patent was held not, by itself, dispositive -- illustrations are not claims. See Adidas Fabrique de Chaussures de Sport v. Andmore Sportswear Corp., 578 F. Supp. 1569, 1574-75 (S.D.N.Y. 1984). What matters is the claimed subject matter, compared feature to feature.

The "Identity of Features" Test and "Cross-Reading"

Out of the case law emerged a workable standard sometimes called the identity-of-features test. Impermissible double patenting exists where "the feature in which the novel aesthetic effect resides is the identical feature which produces the novel function, so that a structure embodying the [utility] invention would of necessity embody the design, and vice versa." Put differently, the two patents impermissibly overlap when they "cross-read" -- when each patent would necessarily be infringed by practicing the other. Carman Industries, Inc. v. Wahl, 724 F.2d 932, 939-40 (Fed. Cir. 1983).

The analysis runs in both directions. There is impermissible double patenting if the design claimed in the first patent cannot be made or used without infringing the utility patent. There is no double patenting, however, if the utility claim encompasses designs other than the patented one -- that is, if one claim could be literally infringed without literally infringing the other.

Two cautions guide the inquiry. First, double patenting in the design-utility setting "cannot turn on niceties of precise ornamentation"; it must turn on whether the design features that produce the novel function are the same features claimed in the utility patent. If trivial decorative variations -- which contribute nothing to the novel function -- were allowed to defeat the comparison, it would become almost impossible ever to find design-utility double patenting. Ropat Corp. v. McGraw-Edison Co., 535 F.2d 378, 382 (7th Cir. 1976). Second, courts have recognized the genuine difficulty of separating ornamental from functional aspects and have suggested the standard should not be applied too rigorously against the patentee. Wahl v. Rexnord, Inc., 624 F.2d 1169, 1181 (3d Cir. 1980); In re Wahl, 511 F.2d 1196 (C.C.P.A. 1975); see also Carman Industries, 724 F.2d at 940-41. Conversely, the comparison does not demand perfect symmetry: a utility patent and a design patent "need not each claim every incidental feature of the other in order for them both to claim the 'same invention'" for double-patenting purposes, so the analysis looks to the essential overlapping features rather than to a mechanical, claim-word-for-claim-word match. Transmatic, Inc. v. Gulton Industries, Inc., 442 F. Supp. 911 (E.D. Mich. 1977), rev'd on other grounds, 601 F.2d 904 (6th Cir. 1979).

Worked Illustrations from the Case Law

Several decisions illustrate the line in operation. Courts and the Patent Office found impermissible double patenting where:

  • A utility claim for a fluorescent light bulb covered the same essential features as a previously issued design patent on the same device. In re Thorington, 418 F.2d 528 (C.C.P.A. 1969).
  • A utility claim for a finger ring added nothing of substance beyond an earlier design patent on the ring. In re Phelan, 205 F.2d 183 (C.C.P.A. 1953).
  • A design claim for a flashlight cap and hanger ring overlapped a utility patent such that allowing both would extend the monopoly on the same features. In re Barber, 81 F.2d 231 (C.C.P.A. 1936).
  • A utility claim covering a balloon-tire construction overlapped an earlier design patent. In re Hargraves, 53 F.2d 900 (C.C.P.A. 1931).

Conversely, courts permitted concurrent protection where the design patent protected ornamental features genuinely separate from the functional innovation -- as in the roofing-shingle illustration above -- and where the utility claim swept more broadly than the single patented design. The Federal Circuit has treated membership in different statutory classes as a factor against double patenting, see Studiengesellschaft Kohle mbH v. Northern Petrochemical Co., 784 F.2d 351 (Fed. Cir. 1986), and has declined to find ODP where a utility application's generic reference to "facial indicia" was not "basically the same as the claimed design" depicting particular facial details. In re Dembiczak, 175 F.3d 994, 1001-02 (Fed. Cir. 1999). The bottom line is that the patentable-distinctness comparison in cross-type ODP, as in all ODP, is claim-focused and rigorous, not a loose impression of similarity.

The Two-Way Test in Design-Utility Cases

A doctrinal wrinkle particular to this intersection deserves attention. Ordinarily, ODP uses a one-way test: the examiner asks only whether the challenged claim is patentably distinct from the reference claim, treating the reference as though it were prior art. A more forgiving two-way test -- which requires the challenged claim to be indistinct from the reference and the reference to be indistinct from the challenged claim -- favors the patentee and makes an ODP finding less likely. In re Braat, 937 F.2d 589, 593-94 (Fed. Cir. 1991). It is reserved for the unusual situation in which the patentee was not at fault for the order in which the patents issued and could not have filed all the claims in one application; in ordinary utility-versus-utility cases, the two-way test applies only when the USPTO's own processing delays caused a later-filed application to issue first, and never where the patentee gamed the timing. In re Berg, 140 F.3d 1428, 1432 (Fed. Cir. 1998); In re Janssen Biotech, Inc., 880 F.3d 1315, 1325-26 (Fed. Cir. 2018); Gilead Scis., Inc. v. Natco Pharma Ltd., 753 F.3d 1208, 1217 (Fed. Cir. 2014).

The design-utility context is special. Because an applicant generally cannot file design and utility claims in a single application -- they are examined by different art units under different rules, and the design must be claimed in a single drawing-based claim -- the Federal Circuit has held that the more patentee-favorable two-way test normally applies in utility-design ODP situations without requiring the USPTO-delay showing that utility-utility cases demand. Carman Industries, 724 F.2d at 940-41; MPEP Section 804(II)(B)(4). This is a meaningful thumb on the scale in favor of allowing concurrent protection, and practitioners defending against a cross-type ODP rejection should invoke it expressly.

The Section 121 Divisional Safe Harbor

A second structural defense is worth knowing. Under 35 U.S.C. Section 121, when the USPTO itself forces an applicant to split an application by issuing a restriction requirement -- a demand that the applicant elect among independent and distinct inventions -- the resulting divisional application and its parent cannot be used as ODP references against each other. The rationale is one of basic fairness: it would be perverse to let the Office require the split and then punish the applicant for the very division it commanded. The safe harbor is narrow and consensual-restriction-driven; it protects only patents that issue on applications filed as a result of (and consonant with) the examiner's restriction requirement, and the Federal Circuit polices its boundaries strictly. See Boehringer Ingelheim Int'l GmbH v. Barr Labs., Inc., 592 F.3d 1340 (Fed. Cir. 2010). Where it applies, however, it is a complete answer to an ODP rejection, no disclaimer required.

The Common-Ownership and Common-Inventor Requirement

ODP only bites where the two patents are related -- typically through common ownership, a qualifying joint research agreement, or at least one common inventor. In re Hubbell, 709 F.3d at 1146-47; In re Fallaux, 564 F.3d 1313, 1319 (Fed. Cir. 2009). For the design-utility strategist, two refinements matter. First, "common ownership" means one entity holds all substantial rights; indirect ownership through subsidiaries may not suffice. Bayer CropScience AG v. Dow Agrosciences LLC, 680 F. App'x 985, 994-95 (Fed. Cir. 2017); cf. Immunex Corp. v. Sandoz Inc., 964 F.3d 1049, 1059 (Fed. Cir. 2020). Second -- and this is the trap -- where two patents share only a common inventor but not common ownership, a terminal disclaimer is not available to cure the ODP, because the disclaimer mechanism depends on the patents remaining commonly owned. In re Hubbell, 709 F.3d at 1146-47. A company assembling a portfolio across affiliated entities should map ownership deliberately before relying on the disclaimer fix.

Terminal Disclaimers: The Practical Fix

When ODP cannot be argued away, it can usually be disclaimed away. A terminal disclaimer is a formal statement, filed at the USPTO under 35 U.S.C. Section 253(b) and 37 C.F.R. Section 1.321, in which the patent owner gives up ("disclaims") any part of the later patent's term that would extend beyond the expiration of the earlier patent, and agrees that the two patents will remain commonly owned and enforceable only together. By doing so, the patentee removes the two evils ODP guards against: there is no timewise extension (both patents now expire together), and there can be no separate-assignee suits (the patents must stay in common ownership). A terminal disclaimer is fast, inexpensive, and available at any time -- even during litigation -- but it cures ODP only, not statutory same-invention double patenting, and it is unavailable where the only link between two patents is a common inventor without common ownership. In re Hubbell, 709 F.3d at 1146-47.

A timely caveat for clients worried about the downstream consequences of disclaiming: in May 2024 the USPTO proposed a controversial rule that would have made any patent tied by a terminal disclaimer unenforceable if a single claim in the linked reference patent were ever held invalid over the prior art -- a change that would have let a challenger topple a whole family by knocking out one claim. 89 Fed. Reg. 40439 (May 10, 2024). After receiving more than 300 mostly hostile comments, the USPTO withdrew the proposal in December 2024, citing resource constraints, so existing terminal-disclaimer practice remains intact. The episode is a useful reminder that the disclaimer's "enforceable only together" condition can be a sleeping liability, and that proposals to sharpen its bite resurface periodically; counsel should track the rulemaking docket before betting a portfolio on a disclaimer.

In the design-utility setting, terminal disclaimers carry a peculiar cost worth flagging. Because design and utility patents have different term structures -- fifteen years from issuance versus twenty years from filing -- disclaiming the terminal portion of one to match the other can forfeit a meaningful slice of exclusivity, and the issuance-based and filing-based clocks can produce a counterintuitive earlier expiration. Run the dates carefully. In many cases the better strategy is to defeat the ODP rejection on the merits -- invoking the two-way test, the cross-reading standard, or the Section 121 safe harbor above -- rather than to surrender term. The mechanics of statutory and terminal disclaimers, certificates of correction, and related prosecution tools are covered more fully in the firm's materials on responding to patent office actions.

Part Five: Two Very Different Infringement Tests

If a competitor copies Acme's water bottle, the analysis of whether the utility patent is infringed and whether the design patent is infringed proceeds along entirely separate tracks. (For a litigation-focused treatment of the design side, see the firm's article on design-patent litigation.)

Utility Patent Infringement: Claim Construction, Then Comparison

Utility-patent infringement is a two-step inquiry. First, the court construes the claims -- it determines, as a matter of law, what the words of each claim mean, a process governed by Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996), and conducted using the intrinsic evidence (claims, specification, prosecution history) and, where necessary, extrinsic evidence. Second, the fact-finder compares the properly construed claims to the accused product limitation by limitation. There is literal infringement if the accused product contains every limitation of a claim. There is infringement under the doctrine of equivalents if any missing limitation is met by an element that performs substantially the same function in substantially the same way to achieve substantially the same result -- a doctrine cabined by prosecution-history estoppel and other limits. The accused infringer can defend on non-infringement, on invalidity (anticipation, obviousness, indefiniteness, lack of enablement), and on equitable grounds. The firm's overview of what constitutes patent infringement develops these mechanics.

Design Patent Infringement: The Ordinary-Observer Test

Design-patent infringement is governed by a fundamentally visual test. The court still "construes" the claim in a limited sense -- it identifies, from the drawings, the protected ornamental design and seeks to distinguish the design's ornamental features from any unprotectable functional ones -- but it generally does not translate the design into a verbose verbal description, because doing so risks importing limitations the drawings do not contain. The infringement comparison then applies the ordinary-observer test announced by the Supreme Court in Gorham Manufacturing Co. v. White, 81 U.S. (14 Wall.) 511 (1871), and reaffirmed by the en banc Federal Circuit in Egyptian Goddess, Inc. v. Swisa, Inc., 543 F.3d 665 (Fed. Cir. 2008).

Under the ordinary-observer test, infringement exists if, "in the eye of an ordinary observer, giving such attention as a purchaser usually gives, two designs are substantially the same" -- so substantially the same that the resemblance deceives the observer, "inducing him to purchase one supposing it to be the other." Gorham, 81 U.S. at 528. Egyptian Goddess made two key clarifications. First, it abolished the separate "point of novelty" test that had previously required the patentee to show the accused design appropriated the specific novel feature distinguishing the patented design from the prior art; the ordinary-observer test is now the sole test for design-patent infringement. Second, it directed that the comparison be conducted in the context of the prior art: where the patented design and the accused design are both close to crowded prior art, an ordinary observer familiar with that prior art will attend to small differences, and minor distinctions can defeat infringement. The comparison is of the designs as a whole, not an element-by-element dissection. Int'l Seaway Trading Corp. v. Walgreens Corp., 589 F.3d 1233, 1239-40 (Fed. Cir. 2009). And notably, there is no separate doctrine of equivalents in design-patent law -- the "substantially the same" inquiry already subsumes it.

The practical upshot is that the same act of copying may infringe a utility patent under the limitation-matching analysis and a design patent under the visual analysis, but a competitor can also infringe one without the other. A "knockoff" that copies Acme's silhouette but uses a completely different (e.g., licensed or off-patent) valve infringes the design patent but not the utility patent. A functional clone that copies the valve but houses it in an utterly different-looking bottle infringes the utility patent but not the design patent. This is exactly why concurrent protection is so valuable: it closes off two different avenues of imitation.

Part Six: Damages, and Why Design Patents Hit Harder

The General Patent Damages Framework

For both regimes, 35 U.S.C. Section 284 guarantees damages "adequate to compensate for the infringement, but in no event less than a reasonable royalty." A patentee who can prove it lost sales to the infringer may recover lost profits; otherwise it recovers a reasonable royalty, typically modeled on a hypothetical negotiation between a willing licensor and willing licensee. Enhanced damages up to treble the award are available for willful infringement under Section 284 as construed by Halo Electronics, Inc. v. Pulse Electronics, Inc., 579 U.S. 93 (2016). These remedies are available for utility and design patents alike.

The Design-Patent Total-Profit Rule (35 U.S.C. Section 289)

Design patents come with an additional, and potentially devastating, remedy that has no analogue in utility-patent law. Under 35 U.S.C. Section 289, anyone who applies a patented design (or a colorable imitation of it) to "any article of manufacture for the purpose of sale," or sells such an article, "shall be liable to the owner to the extent of his total profit, but not less than $250." In other words, the design-patent owner can recover the infringer's entire profit on the infringing article -- not merely a royalty, and without having to apportion the profit between the design and the rest of the product. This is an extraordinary remedy: it can dwarf what a utility patent on the same product would yield, because a reasonable royalty is typically a small fraction of the sale price while total profit can be the whole margin.

Samsung v. Apple and the "Article of Manufacture" Question

The reach of Section 289 was the central issue in Samsung Electronics Co. v. Apple Inc., 580 U.S. 53 (2016). Apple held design patents on aspects of the iPhone's appearance -- a black rounded-rectangle front face, a surrounding bezel, and a grid of colorful icons -- and a jury awarded Apple Samsung's entire profit on the infringing smartphones, hundreds of millions of dollars, on the theory that the relevant "article of manufacture" was the whole phone. The Supreme Court unanimously reversed that reading. The key question, the Court held, is what the relevant "article of manufacture" is: it may be the entire end product sold to a consumer, but it may instead be only a component of that product. The "total profit" recoverable under Section 289 is the total profit attributable to that article of manufacture -- which, when the design is applied only to a component, is the profit on the component, not the entire multicomponent device. Samsung, 580 U.S. at 60-65.

The Court declined to set out a test for identifying the relevant article of manufacture, leaving that to the lower courts. On remand, the district court adopted a four-factor framework (drawn from the Solicitor General's brief and often called the Apple/Nordock factors): (1) the scope of the design as claimed in the patent, including the drawings and written description; (2) the relative prominence of the design within the product as a whole; (3) whether the design is conceptually distinct from the product as a whole; and (4) the physical relationship between the patented design and the rest of the product, including whether the design pertains to a separable component. These factors now guide the Section 289 inquiry. The doctrinal bottom line is that Section 289 remains a uniquely powerful remedy -- but after Samsung, the patentee must establish that the relevant article of manufacture truly is the entire product if it wants the entire profit, and a defendant can argue the design is confined to a component. Notice, too, how this dovetails with Curver: the way the patent identifies and depicts the article of manufacture drives both infringement scope and the damages base.

For Acme's water bottle, the analysis is comparatively simple: the design covers the whole bottle's silhouette, the bottle is sold as a unitary article, and the design is the dominant visual feature -- so under the Samsung factors the "article of manufacture" is likely the whole bottle, and Acme could pursue the infringer's total profit on every bottle sold. That remedy is typically far more valuable than the reasonable royalty Acme could obtain on the utility patent alone -- one more reason the design patent is worth pursuing.

Part Seven: LKQ v. GM and the New Law of Design-Patent Obviousness

No discussion of the modern design-utility intersection is complete without LKQ Corp. v. GM Global Technology Operations LLC, 102 F.4th 1280 (Fed. Cir. 2024) (en banc), which reshaped how design-patent obviousness is analyzed and therefore reshaped both validity and prosecution strategy for the design half of a concurrent-protection portfolio.

What LKQ Changed

For decades, design-patent obviousness under Section 103 had been governed by a rigid, two-part framework derived from In re Rosen, 673 F.2d 388 (C.C.P.A. 1982), and Durling v. Spectrum Furniture Co., 101 F.3d 100 (Fed. Cir. 1996). Under that "Rosen-Durling" test, a challenger first had to identify a single primary reference -- a so-called Rosen reference -- that was "basically the same" as the claimed design, and only then could secondary references be used to modify it, and only if those secondary references were "so related" to the primary reference that features of one would suggest application to the other. These threshold requirements were demanding and made design patents notoriously hard to invalidate for obviousness.

In LKQ, the en banc Federal Circuit overruled the rigid Rosen-Durling test, holding it inconsistent with the Supreme Court's flexible obviousness jurisprudence in KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007), and with the unitary obviousness standard of Graham v. John Deere Co., 383 U.S. 1 (1966). Going forward, design-patent obviousness is analyzed under the same flexible Graham framework that governs utility patents: (1) the scope and content of the prior art; (2) the differences between the prior art and the claimed design; (3) the level of ordinary skill in the pertinent art; and (4) secondary considerations such as commercial success, industry praise, and copying. A primary reference is still the natural starting point and must be "something in existence" with design characteristics visually similar to the claimed design, but it need no longer be "basically the same," and the rigid "so related" requirement for secondary references is gone. The relevant perspective remains that of an ordinary designer in the field. The companion firm article, the LKQ decision: a seismic shift in design-patent obviousness analysis, develops the holding, its rationale, and its open questions in detail.

Why LKQ Matters at the Intersection

For a company pursuing concurrent protection, LKQ has three practical consequences. First, it makes design patents somewhat easier to invalidate for obviousness, so the design half of a portfolio is more exposed than it was, and applicants should build more original, less prior-art-adjacent designs into their products. Second, it brings design and utility obviousness into doctrinal alignment, which means the same Graham/KSR obviousness fluency a practitioner uses for utility patents now transfers to design patents -- a point of overlap that did not exist before, and one that also surfaces in the cross-type ODP analysis, which borrows the same obviousness machinery. Third, it heightens the value of secondary considerations (commercial success, copying, industry praise) for design patents -- evidence a savvy patentee should begin documenting from launch. Because design and utility obviousness now share the Graham framework, the firm's guide to overcoming obviousness rejections under Section 103 is directly relevant to defending design claims as well.

Part Eight: A Worked Example -- Acme's Water Bottle, Start to Finish

Let us follow Acme Corp.'s water bottle through the entire system to see how the doctrines fit together. (This scenario is entirely hypothetical and is offered only to illustrate the doctrine.)

Step 1 -- Identifying the two innovations. Acme's engineers invent a no-tilt drinking valve (a function) and Acme's industrial designers create a distinctive hourglass-with-a-twist silhouette (an appearance). These are conceptually distinct: the valve lives inside the cap; the silhouette is the outer shape of the body. Many different body shapes could house the same valve, and many different valves could sit inside the same silhouette.

Step 2 -- Filing strategy. Acme files a utility application claiming the valve mechanism and its method of operation, supported by a Section 112 written description and enabling disclosure. Separately, Acme files a design application claiming "the ornamental design for a water bottle as shown," with drawings depicting the silhouette in seven views. Because design and utility claims cannot live in one application, two filings are necessary. Acme's docketing team flags that the design application's foreign-priority window is only six months (versus twelve for the utility application) and that the design cannot claim provisional benefit. Acme also considers whether the utility application can claim priority to the earlier design application under 35 U.S.C. Section 120 -- permissible only if the design application's disclosure satisfies the Section 112 written-description and enablement requirements for the utility claims, which a drawing-only design disclosure frequently will not. Finally, Acme coordinates the two specifications so the utility patent does not advertise as "functional" the very contours the design patent claims as ornamental -- avoiding the PHG Technologies "concomitant utility patent" trap.

Step 3 -- The functionality bar. During design examination, Acme demonstrates that the claimed silhouette is primarily ornamental: numerous alternative body shapes could perform the bottle's holding-and-pouring function equally well, the silhouette was created for aesthetic appeal, and its consumer appeal does not make it "functional" under Sport Dimension and Automotive Body Parts. The design clears Section 171. Acme is also careful, per Curver, to identify and depict the article of manufacture (the bottle) precisely, so the design patent's scope is not accidentally narrowed or expanded.

Step 4 -- Obviousness, post-LKQ. The design examiner (and any later challenger) analyzes the silhouette's obviousness under the Graham framework as reframed by LKQ: scope and content of prior bottle designs, the differences from Acme's silhouette, the level of skill of an ordinary bottle designer, and secondary considerations. Acme has, wisely, been documenting the silhouette's commercial success and instances of competitor copying since launch, strengthening the case for non-obviousness. The utility claims undergo a parallel Section 103 analysis aimed at the valve's function.

Step 5 -- Double patenting. An examiner notices that both applications cover the same product and considers an obviousness-type double-patenting rejection. Acme responds that there is no cross-reading: a competitor could practice the valve (infringing the utility patent) inside an entirely different-looking bottle without infringing the design patent, and could copy the silhouette without using the valve. The feature that produces the novel function (the internal valve) is not the feature that produces the novel appearance (the external silhouette). Under Carman Industries, the patentee-favorable two-way test applies in this utility-design setting without any USPTO-delay showing, and under that test the two patents are patentably distinct. (Had the design split off from the utility application by way of an examiner's restriction requirement, the Section 121 safe harbor would have supplied an additional, independent defense.) The rejection is withdrawn. Acme does not need a terminal disclaimer and so keeps the full, separately running terms of both patents -- twenty years from filing for the utility patent, fifteen years from issuance for the design patent.

Step 6 -- Enforcement against two kinds of copyist. Two competitors later appear. Copyist A sells a bottle with Acme's exact silhouette but a conventional screw cap. Copyist B sells an ugly, square bottle that nonetheless incorporates Acme's no-tilt valve. Acme sues both. Against Copyist A, Acme prevails on the design patent under the ordinary-observer test of Egyptian Goddess -- an ordinary purchaser, familiar with the prior art, would find the two silhouettes substantially the same -- and recovers Copyist A's total profit on every infringing bottle under Section 289, the whole bottle being the relevant article of manufacture under Samsung. Against Copyist B, the design claim fails (the square bottle looks nothing like Acme's), but Acme prevails on the utility patent through claim construction and limitation-by-limitation comparison, recovering lost profits or a reasonable royalty under Section 284. Neither competitor could be reached by the other patent. The dual portfolio caught both.

This example shows the core lesson: concurrent protection is powerful precisely because the two patents guard against different forms of imitation and offer different, complementary remedies -- but it is sustainable only when the ornamental and functional innovations are genuinely distinct, so that double patenting does not collapse the two into one.

Part Nine: Strategic Considerations and Recent Trends

Term, Timing, and the Hague Agreement

The fifteen-year, issuance-based design term and the twenty-year, filing-based utility term interact in ways worth planning around. Because the design clock starts at issuance and is immune from prosecution delay, a design patent can sometimes outlast a utility patent on the same product, especially where the utility patent endured a long prosecution. U.S. accession to the Hague Agreement also lets applicants pursue international design protection through a single filing, an increasingly important consideration for products sold globally. Coordinate the timing of design and utility filings to optimize total coverage and to preserve priority claims -- remembering the design application's shorter, six-month foreign-priority window.

Licensing and Marking the Dual Portfolio

A dual portfolio is also a licensing and enforcement asset, and it should be managed like one. When licensing, parties should specify which patents are in scope, allocate the asymmetric remedies (a licensee will care a great deal that Section 289 total profit is on the table), and address improvements to both the functional and ornamental sides; see the firm's guidance on licensing a patent from valuation to term sheet. On the enforcement side, both patents should be properly marked to preserve pre-suit damages under 35 U.S.C. Section 287; the marking rules and their pitfalls are covered in understanding patent and trade dress marking requirements.

Emerging Technologies

The design-utility boundary is under fresh pressure from new technologies. Graphical user interfaces and animated icons blur the line between functional method and ornamental display. 3D printing lets a single digital file embody both a functional structure and an ornamental form, complicating both infringement and the "article of manufacture" inquiry. And AI-generated designs raise inventorship and ornamentality questions the doctrine has not fully absorbed; the firm's article on AI-generated inventions and who owns what the machine creates explores the inventorship dimension. As form and function continue to converge in software-driven products, the careful, claim-focused, cross-reading analysis described here will only grow in importance.

Layering Patents With Trade Dress and Copyright

Finally, design patents do not exist in isolation. The same product appearance that supports a design patent may, once it has acquired consumer recognition as a source identifier, also support federal trade dress protection under the Lanham Act -- which, unlike a patent, can last indefinitely so long as it remains distinctive and non-functional. And certain separable ornamental features may qualify for copyright protection. A complete protection strategy layers these regimes deliberately, timing the design patent to provide strong early exclusivity while trade dress recognition develops. The interplay is analyzed in the firm's companion pieces on design patents versus trade dress protection for product configurations and on the legal protection of software through copyrights, patents, trade secrets, and contracts.

Key Takeaways

  • Two regimes, two targets. Utility patents (Section 101) protect function for twenty years from filing, with maintenance fees; design patents (Section 171) protect ornamental appearance for fifteen years from issuance, with none. Each has its own claim format, examination perspective, infringement test, and remedies -- and its own priority deadlines (design foreign priority is just six months).
  • Concurrent protection is permitted and often wise. There is no per se bar to holding both a design and a utility patent on the same product, and doing so closes off both functional cloning and visual knockoffs.
  • The functionality bar polices the boundary. A design is protectable only if primarily ornamental, not dictated by function; the availability of alternative designs is the strongest signal of ornamentality, and mere aesthetic appeal does not make a design "functional." Beware the "concomitant utility patent" that brands your ornamental lines as functional.
  • Double patenting is the principal internal risk. Cross-type ODP arises when the design and utility patents "cross-read" -- when the same feature produces both the novel appearance and the novel function. The patentee-favorable two-way test of Carman Industries normally applies in design-utility cases without a USPTO-delay showing, the Section 121 safe harbor protects examiner-mandated divisionals, and terminal disclaimers can cure ODP -- though at a possible cost in term, and not where ownership is split.
  • The infringement tests differ sharply. Utility infringement turns on claim construction and limitation-matching; design infringement turns on the visual ordinary-observer test of Gorham and Egyptian Goddess, judged in light of the prior art, with no separate doctrine of equivalents.
  • Section 289 is a uniquely powerful design remedy. Subject to the "article of manufacture" limitation recognized in Samsung v. Apple, a design-patent owner may recover the infringer's total profit -- often far exceeding what a utility patent would yield. How you identify the article (per Curver) shapes both infringement and the damages base.
  • LKQ changed design obviousness. Design-patent obviousness now follows the flexible Graham/KSR framework, making design patents somewhat easier to challenge and aligning design and utility obviousness analysis (and, with it, the ODP comparison).

Frequently Asked Questions

Can I get both a design patent and a utility patent on the same product? Yes. There is no per se prohibition. The utility patent protects how the product works and the design patent protects how it looks, and a single article frequently embodies both kinds of innovation. The two filings must be separate, because design and utility claims cannot coexist in one application -- and watch the design application's shorter, six-month foreign-priority window.

Does holding both patents create "double patenting"? Not necessarily. Double patenting is a problem only when the two patents claim, in substance, the same invention -- specifically, when the feature that produces the novel function is the same feature that produces the novel appearance, so the patents "cross-read." If the functional and ornamental innovations reside in different features (or the same function could be achieved with many different appearances), there is no impermissible double patenting. In design-utility cases, courts apply a patentee-favorable two-way test, and the Section 121 safe harbor protects divisionals filed in response to an examiner's restriction requirement.

What is the difference between an "ornamental" and a "functional" design? An ornamental design is one created for visual appeal; a functional design is one whose shape is dictated by what the product must do. The key evidence is whether alternative designs could achieve the same function -- if so, the chosen design is likely ornamental and protectable. A design does not become "functional" merely because consumers find it attractive. Be careful, though: a companion utility patent that describes a feature as functional can be used to attack the design patent covering that same feature.

Which patent gives the stronger remedy if someone copies my product? It depends on what was copied. A visual knockoff is best attacked with the design patent, which under 35 U.S.C. Section 289 can yield the infringer's total profit on the article (subject to the article-of-manufacture limitation from Samsung v. Apple). A functional clone is best attacked with the utility patent, which yields lost profits or a reasonable royalty. Holding both lets you reach both kinds of copyist.

How did the LKQ decision change design patents? In LKQ Corp. v. GM (Fed. Cir. 2024) (en banc), the court discarded the rigid Rosen-Durling test for design-patent obviousness and replaced it with the flexible Graham/KSR framework used for utility patents. Design patents are now somewhat easier to challenge for obviousness, and documenting commercial success and copying has become more important.

What is a terminal disclaimer, and should I file one? A terminal disclaimer is a filing under 35 U.S.C. Section 253(b) that gives up any portion of a later patent's term extending beyond an earlier related patent's expiration and keeps the patents commonly owned, curing obviousness-type double patenting. It can be useful, but because design and utility terms run on different clocks, a disclaimer can forfeit valuable term -- so it is often better to defeat the double-patenting rejection on the merits first. Note also that the USPTO proposed (and in December 2024 withdrew) a rule that would have made terminally disclaimed patents unenforceable if a linked patent's claim were invalidated; the proposal's failure leaves current practice intact, but the topic bears watching.

Can I file my design and utility claims in one application to save money? No. Design and utility applications are examined under different rules by different art units, and a design must be claimed in a single drawing-based claim. The inability to combine them is precisely why the patentee-favorable two-way ODP test applies to design-utility conflicts.

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This article is provided by mclaw.io for general informational purposes only and does not constitute legal advice. The law in this area is fact-specific and evolving, and nothing here creates an attorney-client relationship. Readers facing actual or potential patent issues should consult qualified patent counsel licensed to practice before the U.S. Patent and Trademark Office and admitted in the relevant jurisdiction.