Despite the fact that design patents and utility patents coexist largely under the same body of laws, our tendency is sometimes to discuss design patents and utility patents as being two different, albeit related, things. Indeed, as we know, design patents only protect the ornamental aspects of an invention, while, for example, a utility patent can protect the structure of the invention. As we go about our business, we might think that these two types of patents live separate lives, ne’er to cross paths with one another due to the complementary nature of their coexistence.
Yet lurking deep within the magnum opus otherwise known as the Manual of Patent Examining Procedure (MPEP) are several interesting sections that discuss one uncommon intersection between design and utility patents – the ability of a design patent to anticipate the claims of a utility patent application. To wit: “Drawings and pictures can anticipate claims if they clearly show the structure which is claimed.” MPEP 2125. This is to say, if a drawing in a design patent reasonably discloses a claimed structural feature, the drawing can be used by a patent examiner to reject a claim in a utility application! To qualify as prior art, the drawings in a design patent must constitute an enabling disclosure. “[A]n enabling picture may be used to reject claims to the article. However, the picture must show all the claimed structural features and how they are put together.” MPEP 2121.04.
Although the Board of Patent Appeals and Interferences rarely issues opinions relating to design patents, a recent decision discussed an examiner’s §103(a) obviousness rejection of a claim in a utility application based in part on a design patent that illustrated a device similar to the one being claimed. What saves the applicants (at least for the time being) is their argument that the drawings in the design patent do not sufficiently disclose the structure or the function of the claimed element (an inwardly extending flange). In this instance, the BPAI agreed.
Which brings us to a caveat: since patent drawings are not necessarily drawn to scale, those drawings cannot be used as evidence of the size or proportion of the features they disclose unless explicitly described. This is notable particularly because design patents typically do not speak to the dimensions or functional characteristics of the claimed design, and therefore examiners face a challenge in using those drawings as a basis of rejecting the structural or functional limitations of a utility application claim.
Thus there is an interesting interplay between design and utility patents that arises (although rarely) during the prosecution of utility patents which does not usually come to mind. Nevertheless, it does make sense that the pictures in a design patent could be used as prior art against a utility application, since prior art can be just about anything disclosed to the public – including design patents.