The U.S. IP laws usually do not overlap one another. When it comes to design of 3D useful articles, however, copyright, trademark and patent can intersect to provide potential treble IP protection.
Copyright protects the design of 3D articles if the design is aesthetic and not functional. It is becoming common to see highly stylized goods, including coffee makers, kitchen accessories, buildings, television sets, computers, fire extinguishers and many other high-design articles. The test for copyright protection relates to the separation of the design from the useful component of the article. If it is possible to conceive of a separation or distinction between the aesthetic design and the utilitarian useful component of the article, then the design is copyright protectable. Consider the functional belt buckle. The buckle is certainly utilitarian when it latches and holds up the trousers. The stylized design on the front of the buckle, however, expresses no useful purpose and serves as a design element only. The design on the front of the buckle is copyright protectable while the working part of the buckle is not.
Trademark protects the design of a useful article provided the design serves as a trademark source-identifier. In doing so, the design accomplishes the goal of the trademark -- to communicate source, origination, association and characteristics of the article to the consumer. All sorts of 3D designs fullfill this mission as a trademark communicator. One well known 3D symbol is the Coca Cola bottle. The bottle is certainly functional, but a functional bottle need not express the same shape as a Coke bottle. Other shapes can hold liquids just as well. But the shape of the Cole bottle does more - it communicates a brand message to consumers regarding the source and contents. Hence, the 3D design becomes the trademark.
Patent design protection is perhaps the most well known form of design protection in the U.S. A patent design of a 3D article protects the new, novel and nonobvious aspects of the design that are non-functional.
The differences between the protection of design afforded by each of the IP laws derives from the purpose of each law. Neither trademark law nor copyright law require the newness, novelty or nonobviousness of design as is required by patent law. A valid copyright requires only a minimal degree of nonfunctional creativity, whether or not the resulting design is novel or non-obvious. For a valid trademark, the aesthetic design must serve a trademark's traditional source-identifier function. Plus, the trademark design of the article must be recognized by consumers as a trademark as opposed to a product design. This requirement of "secondary meaning" in order to obtain a trademark for a product design usually means that the design must be in use for at least five years in order to obtain trademark design protection.
Another important distinction between the three IP laws concerns the term of protection. Copyright protection commences upon creation (whether or not a form is filed with the U.S. Copyright Office) and lasts for the life of the author plus 70 years. A trademark commences upon use (whether or not a form is filed with the PTO) and can potentially last forever, so long as the design is used as a source identifying trademark. A patent design commences only upon issuance of an issued patent (formal application to the PTO is required) and lasts for fourteen years following the grant issued by the PTO.