When people develop new products or services, they often refer to the first stage of development as "designing the product." Among the aspects of designing a product are defining what the product does, how it does it and how the product is structured and built.
This is perfectly correct English, and nobody misunderstands what the meaning of such statement. This use of the word 'design," however, sometimes misleads those not familiar with the patent process. It is easy to assume that the design of a product is protected using a design patent. This in incorrect. Design patents only cover decorative aspects of a physical product. What the product does, how it does it, and how it is structured and built are irrelevant in a design patent. A design patent is best understood as a decorative design patent. Utility patents cover what a product does, how it does it and how the product is structured and built.
Stated more concisely, design patents cover how a product looks and a utility patent covers how the product works.
A given product may be covered by both utility and design patents. There is no overlap in coverage between the two. Any aspects of a product that does something, referred to "functional" aspects of the product, are covered by utility patents, but not design patents. Any aspects of a product that are purely decorative, referred to "non-functional" aspects of the product, are covered by design patents, but not utility patents.
Decorative aspects of a product can be any externally visible, non-functional, elements of a product (decorations that are not visible when the product is used as intended don't count). Such non-functional elements could include, for example product shape and surface decorations.
Note that aspects of a product eligible for design patents might also be separately protectable under copyright law and trademark law (trade dress).
Design patents are generally easier and faster to obtain than utility patents â€¦ and are a good deal cheaper. Government fees to file a design patent application is $190 for micro entities. Attorney's/Agent's fees for preparing and filing the application are also generally significantly below the cost of preparing and filing a non-provisional utility patents.
What's more, design patents are generally much cheaper to enforce in court.