Design vs. Utility
The essential distinction between design and utility patents is the difference between “How it looks” (design) vs. “How it works” (utility). If you’re concerned about competitors copying the appearance of your concept, then apply for design patents. If you want to protect the functional features of your concept, then apply for utility patents. In some cases, it may be appropriate to file design and utility patent applications.
For example, design patent protection would be appropriate for three-dimensional product shapes, but beware of any features that serve functional purposes. Design patents are meant to protect only non-functional, ornamental features. This is where consulting with a patent attorney would help.
Here’s a table broadly summarizing differences between design and utility patents:
As shown above, a design patent costs a fraction of a utility patent application which can easily get into the tens of thousands from start to finish. One major reason is that a utility application requires much more effort in drafting the specification and claims.
Scope of Protection
Since a design patent covers merely the ornamental appearance of an invention, it’s not difficult to imagine the ways in which a competitor may easily design around a patented design by creating a product that simply looks different. Utility patents are tougher to design around. Since utility patents claim the function or structure of an invention, the outer appearance of a product is less relevant to issue of infringement. A competitor may introduce a product with a very different appearance from that of a patented product and still infringe a utility patent.
Probability of Rejection
Utility applications have a significantly higher rate of initial rejection (approx. 80-90%) whereas design applications may often receive a first action allowance. This is due in part to the differences in the claimed subject matter. Whereas the claim in a design application is primarily visual and more limited in scope, the claims in a utility application are textual and generally broader in scope. Broader claims have a higher probability of being rejected over prior art that discloses the claimed subject matter.
Length of Application Process
Since utility applications have a higher rate of rejection, they also endure a longer application process than that of a design application.
Differences in Terms
Design patents expire 15 years from the filing date and require no maintenance/renewal. Utility patents generally expire 20 years from the filing date and three maintenance fees must be paid to keep the patent alive.