When Prior Art is Analogous to a Patent Application’s Claims

When someone files a patent application with the U.S. Patent and Trademark Office, they have an obligation to disclose relevant or analogous prior art.  So when it comes to an examiner or a court determining whether claims should be allowed over prior art references, even when the examiner identifies the art, the prior art needs to be analogous prior art. But how does an applicant know when something actually is analogous according to the Patent Office?

In a recent case before the Court of Appeals for the Federal Circuit (CAFC, not a fact-finding court), Donner Technology, LLC v. Pro Stage Gear, LLC, the question arose in the context of an invalidity inquiry into a granted patent directed to a guitar foot pedal, which is a foot-controlled device to adjust amplification of a guitar’s sound. 

In Donner, the CAFC stated that there are two ways in which the prior art can be considered analogous: “Two separate tests define the scope of analogous prior art: (1) whether the art is from the same field of endeavor, regardless of the problem addressed and, (2) if the reference is not within the field of the inventor’s endeavor, whether the reference still is reasonably pertinent to the particular problem with which the inventor is involved.”  quoting In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004).  In addition, per Donner, “The scope of the prior art includes all analogous art.” citing, e.g., Princeton Biochemicals, Inc. v. Beckman Coulter, Inc., 411 F.3d 1332, 1339 (Fed. Cir. 2005); In re GPAC Inc., 57 F.3d 1573, 1577–78 (Fed. Cir. 1995).

Also, “[w]hether a reference is analogous art is an issue of fact.” In re ICON Health & Fitness, Inc., 496 F.3d 1374, 1378 (Fed. Cir. 2007).  Because it is an issue of fact, it is up to the District Court (or other fact finder) to determine if prior art is “reasonably pertinent” to the problem being solved and therefore “analogous” to allowability of claims.

The patent in suit describes that the invented device overcomes limitations of earlier designs by providing “easy positioning and changing of the individual guitar effects while providing a confined and secure area for cable routing and placement.”  That is, the guitar pedal invention appears to be directed at least in part to to the field of cable routing and placement.

The patent was first being challenged at the Appeal Board of the Patent Office, where the challenger introduced a 1970 reference entitled “Plug-in Relay and Support Therefor”, which disclosed a relay structure including a plug-in base, where the invention includes “one or more relay structures and for providing wiring-channel space for receiving wires that would be connected to the relay structures”. U.S. Patent No. 3,504,311, col. 1, lns. 5—54.  Although the Appeal Board held that the challenger “had not shown that [the reference] falls within the scope of the prior art”, on the surface it appears that there may be at least some relevance of the ‘311 patent to the patent at issue, so the challenger appealed to the CAFC.

Although the reference did not mention guitars or music, was it still “reasonably pertinent to the problem with which the inventor is involved”?  On appeal, the CAFC held that the Appeal Board had failed to consider “the purpose of problems to which” the reference and the patent relate, thereby applying the wrong standard.  While the Court did not go so far as to determine that the patent at issue and the reference were in a same field of endeavor, it vacated the earlier opinion, remanded the case to the Appeal Board, and indicated guidance for making the determination of whether the art is analogous (again, the determination is a finding of fact and is left to the Appeal Board) and then determine whether the patent in suit would remain valid.   The Court went on to indicate that in general, with some small exceptions, the perspective to be applied is one of a person of ordinary skill in the art. 

How does this case impact preparing patent applications?  First, it is common to believe references are relevant only when they are in the same field of endeavor as the patent application, but as seen here, that field might cross over to other fields.  It is important for patent applicants to think broadly about what their invention relates to; this is especially true for applications involving multiple technologies converging into a single products.

If there are relevant prior art references, it is most cost effective to know about them as soon as possible, such as to design around them if necessary.  So when performing patentability or novelty searches, it is important to consider other fields which might impact patentability such as the field of cable placement in this case.  In general, the patent specification should be written to provide adequate description and should detail the problem being solved and specifics to the solution, even distinguishing explicitly over those references. 

In addition, as we have noted in earlier articles, it is important to be as specific as possible in the specification (and to be general as well), and to be specific in many way including arguments distinguishing as much as possible.  Even if a reference is relevant or analogous, an application could still be allowed, especially if there is distinguishing description in the specification.  Indeed, in this case, the Court relied heavily on the specification and saw an example guitar pedal with similarities to a board in the reference but may not have seen distinguishing elements.