Design patents are a type of industrial design right, where the ornamental design of a product can be protected. In most countries design patents are called “Industrial Design” patents.
In most cases, design patent applications have the same filing deadlines and priority due dates as utility patent application. However, there are several differences.
First, PCT patent applications cannot be based on a design patent. Specifically, MPEP chapter 1500 states that design patent applications are not included in the PCT, and the procedures followed for PCT applications are not to be followed for design patents. This essentially means that there is no such thing as a PCT design patent application.
Second, if you file a patent application in a foreign country (this does not mean a PCT application, which can be used as a standard US patent application), then you have six months to claim priority to the foreign patent application from the filing date of the foreign application. For example, if you file a design patent application in Korea, then you have six months to file a design patent application in the United States. This is laid out in 37 C.F.R. 155(B).
Third, if you have a pending United States application or PCT application, you can file a design patent in the United States under 35 U.S.C. 120 claiming priority to the US or PCT application during the pendency of that application. Therefore, as long as the pending US or PCT application has support for the design patent application, you can file the design patent during pendency of the application. Specifically, MPEP 1504.20 states: “Where the conditions of 35 U.S.C. 120 are met, a design application may be considered a continuing application of an earlier utility application. Conversely, this also applies to a utility application relying on the benefit of the filing date of an earlier filed design application. See In re Chu, 66 F.3d 292, 36 USPQ2d 1089 (Fed. Cir. 1995); In re Salmon, 705 F.2d 1579, 217 USPQ 981 (Fed. Cir. 1983). In addition, a design application may claim benefit from an earlier filed PCT application under 35 U.S.C. 120 if the U.S. was designated in the PCT application.”
Fourth, most foreign countries allow you to file a design patent application claiming priority to the PCT application during the pendency of a PCT or 12 months after publication (which would be the full 30 months from filing the PCT application). However, some countries do not. For example, in Korea a design patent application must be filed before publication of the design patent application.