Whoever invents a novel, nonobvious, original and ornamental design for an article of manufacture may obtain a design patent for it.  U.S. design patents are similar in many ways to U.S. utility patents (the “regular” kind; see the general article on patents on this site), but there are important differences.

A principal one of these is the nature of what is covered.  A design patent covers an ornamental appearance of an article, not how it works.  Function doesn’t matter at all.  In fact, if an appearance or shape is solely dictated by the article’s function, that aspect can’t be covered by a design patent.  Functions are covered by utility patents, if they are protectable by patents at all.

The design patent law has been misused in the past by people who ought to know better.  It is NOT a “petty patent.”  It should NOT be used as some sort of cheaper substitute for a utility patent.  And a design patent application should NOT be filed on a device whose shape is entirely dictated by functional considerations, like a Phillips-head machine screw.

But correctly used, design patents can cover product shapes that aren’t protectable as intellectual property in any other way.  If a new product looks different, but functions the same way as a preexisting prior art product, utility patent protection won’t be available for it – but design patent protection might.   The ornamental appearance of a utilitarian article is coverable by a copyright only where the copyrightable work is conceptually separable from the article – as might be the case where a sculpture is used as a table lamp, or where a frieze appears over a doorway.  Most industrially designed articles will not qualify for copyright protection.  Some product shapes (such as the Coca Cola bottle) are protectable as trademarks – but only after the public has come to recognize those shapes as indicia of the source or origin of the product in question.  Most product shapes won’t qualify for this, either.

Design patents can be particularly useful in preventing copyists from knocking off product shapes, where the copyist is intentionally trying to create a competing product that “looks” like the protected product.    A design patent thus affords some protection against competitors trying to “pass off” their goods as those of the design patent owner – even where the protected product shape is not (yet) so distinctive in the minds of the public that its owner can prove that it is entitled to trademark-like protection.

The protection accorded by a design patent is thin, however.  Unlike utility patents, whose coverage is determined by the language of their claims, a design patent’s protection is dictated by what is shown in the drawings.  Product shapes that are identical to what is shown will infringe, or otherwise be covered by, the design patent.  Product shapes that are sufficiently different that an ordinary observer, using such care as he or she would normally employ, would be able to tell the difference between them and the depicted article, won’t be covered a design patent.  It therefore takes only a modest amount of alteration to avoid a design patent’s scope.

Design patent applications are relatively inexpensive to prepare and file.  Most of their cost originates from the preparation of the drawings by a professional patent draftsman.   While the Patent Rules permit design patent applications to be filed with photographs of the article in question, this is not a good idea in many cases.  There will be many instances in which some of the surface of the article should be intentionally omitted as “unadorned and forming no portion of the claimed design”, but this is not possible in a design application that uses photographs.  Sometimes, applicants of utility patent applications can get away with self-prepared drawings, although this often causes problems.  It is never a good idea to attempt to prepare formal design patent drawings pro se.  The rules for such are much stricter than for utility patent applications, and errors in their execution may cause the application to be initially or even finally rejected.

Unlike most utility patents now in force, the term of a U.S. design patent begins on the date that the design patent is issued.  For design patents issuing on applications filed after May 13, 2015, the term is 15 years from the date of issue.  For design patents issuing on earlier applications, the term is 14 years from the date of issue.  US design patents do not require the payment of maintenance fees to stay in force.

The foreign counterparts of U.S. design patents are typically called “registered designs.”  Under the Paris Convention, the Applicant is accorded a grace period before it must file any foreign applications for registered design and still enjoy the U.S. filing date – but this grace period is six months rather than a year.   A single design registration is available to cover the entirety of the European Union.  There is also the Hague Union, an international design registration system that is somewhat similar in its operation to the Patent Cooperation Treaty.  Applying for an international design does not avoid examination of the application at various national patent offices, and the economic and legal benefits of applying under the Hague Union are not completely clear as of the time of writing.