Design Patents vs. Utility Patents
Many inventors familiar with patent protection do not know the difference between design patents and utility patents. A design patent protects the appearance of an invention. A design patent includes a preamble, a specification, drawings that illustrate the outside appearance of an invention, a brief description of each drawing and one claim. Patent no. D683,047 is an example of a design patent. The design specification is usually recited on a single page. My charge for preparation and filing of a design patent application including the drawings and filing fee is about $1,900 at the time of this article. A utility patent protects the functionality of an invention. A utility patent includes a background of the invention, a summary of the invention, a brief description of the drawings, drawings that illustrate the invention, a detailed description of the invention, claims and an abstract. Patent no. 8640396 is an example of a utility patent. The utility patent goes into great detail to describe the invention with words and the numerous drawings. Item numbers are used in the drawings to illustrate features of the invention. Instead of one general claim in the design patent, the utility patent includes about 20 claims to define the scope of the invention. My charge for preparation and filing of a utility patent application including the drawings and filing fee for a relatively simple invention is about $3,600 at the time of this article.
The standard for infringement of a design patent is confusing similarity. For example, a copyist makes a knock-off of the product protected by the design patent. The knock-off infringes the design patent, if a third party views the knock-off and is confused into thinking the knock-off is the patented product. The copyist is then guilty of patent infringement. The standard of confusing similarity is the same used for the infringement of a federal trademark. If a third party is confused into thinking the copyist trademark is the same as the issued trademark, the copyist is guilty of trademark infringement. Infringement of a utility patent occurs when the knock-off includes all the limitations recited in any one of the independent claims. If the knock-off does not include all the limitations recited in any independent claim, the knock-off does not infringe the utility patent.
The bottom line is when do you choose a design patent over a utility patent? If the invention has aesthetic features that are too difficult to describe with words, the design patent is your choice. If the functional aspects of the invention are important, the utility patent is your choice. If your invention includes both functional and aesthetic features, you may file both a design patent application and a utility patent application. However, it is more difficult to obtain a utility patent than a design application. An option is to first file a utility patent application. and if the utility patent application is not allowed, a design continuation-in-part patent application may be filed.