Design Patents vs. Utility Patents: How Do They Differ?

In the United States, patent protection can be split into two primary categories: utility patents and design patents. Each involves different requirements and grants the patent-holder different rights. We know that there are substantial differences between utility patents and design patents, but what is the nature and extent of those differences? 

Many individuals who are interested in obtaining intellectual property protection over patentable subject matter do not quite understand the options at their disposal — they may not realize that there are multiple categories of patents and that (depending on the patent) there can be substantial variations in enforcement mechanisms and requirements.

Design patents are fundamentally different than utility patents.  Where utility patents describe and protect the function of an invention (how it is used and how it works), design patents describe and protect the appearance of the invention.  Importantly, design patents are only granted to those articles where the “design” is purely ornamental, and that too, if the ornamental design is for a useful article of manufacture.  If the design has any effect on the functionality of the article, then a design patent may not be issued.

Consider this example: Suppose that you are considering filing for a design patent for a “phone skin” product that wraps around a cell phone and thereby provides a unique aesthetic different from the default cell phone exterior. Given that the “phone skin” design is purely ornamental (and is meant to aesthetically modify a useful article of manufacture — specifically, a cell phone), you would likely be entitled to file and be issued a design patent.

Now, suppose that your phone skin has some useful functionality built-in.  Imagine that it has a thin solar-powered battery that charges your phone throughout the day, while attached.  Though the design is ornamental, it also has utility — the two cannot be easily separated.  In all likelihood, the fact that the design is not purely ornamental will preclude the possibility of a design patent, unless the design patent is limited to the purely ornamental aspects of the phone skin.

Generally speaking, when the layperson conceives of a “patent” in the traditional sense, they are contemplating a utility patent — and this is not an entirely uninformed or misrepresentative position. The large majority of patents granted in the United States are utility patents (according to a statistical report conducted by the United States Patent and Trademark Office, utility patents comprised over 90 percent of total granted patents in the year 2018 alone).

Utility patents protect any and all new and useful processes, machines, manufacture, or compositions of matter, or any new and useful improvement thereof.  When a utility patent is granted, the patent-holder may enforce their patent against various other designs that function similarly — it is therefore rather broad in its application.  Utility patents must be accompanied by documentation that fully explains how the covered invention works, with technical details sufficient that an expert in the same field could reproduce its function.