Obviousness rejections under 35 U.S.C. § 103 require examiners to establish that a claimed invention would have been obvious to a person of ordinary skill in the art (POSITA) based on prior art references. Typically, prior art in obviousness rejections comes from utility patents, published applications, or other technical references. However, design patents can also be used as prior art in utility applications, and when they are, they present some unique challenges and opportunities for patent prosecutors.

Unlike utility patents, which contain written descriptions and detailed explanations of functionality, design patents focus purely on ornamental appearance. A design patent typically consists only of drawings and a brief claim covering “the ornamental design for” the depicted object. It does not describe the object’s function, technical advantages, or technical problems solved by its structure.

As noted above, despite this difference, design patents can be used as prior art in utility applications. As explained in MPEP § 2125, design and utility patents are examined under different standards, but a design patent may be used in a 35 U.S.C. 103 rejection of a utility patent application if it is analogous art to the claimed invention. Further, the USPTO also recognizes that images, including those in design patents, can constitute prior art. MPEP § 2121.04 explains that drawings and pictures can anticipate claims if they clearly show the structure which is claimed. Thus, in an obviousness rejection of a utility application, the examiner may point to a design patent’s figures to argue that the claimed utility invention incorporates a known shape or configuration in an obvious way.

In making an obviousness rejection, an examiner generally asserts that there was a reason or motivation to modify or combine the references to arrive at the claimed invention and that a reasonable expectation of success existed in making the proposed combination. However, because design patents lack any written description of functionality, they often fail to provide technical motivation for combining references. This distinction creates an important opportunity for applicants to push back against improper obviousness rejections, especially if an examiner provides no reason, or even reasons that aesthetics may form the basis of the motivation.

A recent appeal of a utility application rejection before the PTAB addressed the issue of design patent prior art. Appeal 2023-004002, Application 16/703,32

Claim 1 on appeal, reproduced below, was directed to a bottle shaped container.

1. A bottle-shaped container comprising:
a neck portion;
a body portion; and
a base,
wherein, the body portion has a first recess having a first longitudinal length and a second recess having a second longitudinal length, wherein, a center of the first longitudinal length is aligned with a center of the second longitudinal length at a same axial position such that a distance from the base to the center of the first longitudinal length and the center of the second longitudinal length are equal, wherein the first longitudinal length is different than the second longitudinal length, wherein each longitudinal end of the first recess is axially offset from each longitudinal end of the second recess by a predetermined amount.

The examiner had cited “aesthetic reasons” as establishing motivation to combine features from a drawing of a design patent with another design patent’s drawing to allegedly reach claim 1. The PTAB disagreed:

For the reasons that follow, the Examiner has failed to adequately explain why one of skill in the art would make such a modification. We do not consider aesthetics alone to be a proper basis in this instance, as it essentially amounts to an unsubstantiated design choice modification.

In this way, aesthetic considerations alone are generally insufficient to support a § 103 rejection.
This case illustrates a useful avenue for argument when faced with an examiner who has based a combination on a design patent.

Practical Tips for Patent Prosecutors

Check for Analogous Art Arguments – If the examiner cites a design patent, push back on whether it qualifies as analogous art. If it comes from a different field or is not pertinent to solving the claimed problem, argue that it should not be considered prior art at all. Remember that while this 2-pronged test is sometimes relatively easy to satisfy when the cited art is a utility application, the lack of disclosure in a design patent may present more opportunity to push back on both prongs.
Challenge the Lack of Functional Disclosure – Since design patents do not explain function, argue that they do not provide a proper basis for combining references.
Look for Aesthetic-based Motivations – If the examiner’s rationale for modification is based purely on appearance, highlight the impropriety of this reasoning.

Design patents can serve as prior art in utility applications, but their lack of technical disclosure can limit their effectiveness in supporting obviousness rejections. When facing a rejection based on a design patent, look closely at the examiner’s reasoning—especially whether the modification is allegedly motivated by unsupported functionality or just aesthetics.