Osha Attorneys
Osha Attorneys
Osha Attorneys
Osha Attorneys
Attorney search
Search by

The collective expertise of our global team distinguishes OBWB in the field of Intellectual Property Law. We align our best resources to meet each client's specific needs and we treat each matter with the highest degree of attention and care.

Federal Circuit Strengthens "Field of Endeavor" Prong of the Non-Analogous Art Test

日本語 简体中文  繁體中文  عربي

The Court of Appeals for the Federal Circuit (CAFC or Federal Circuit) recently revisited an important issue directed to the relevance of prior art references for an obviousness rejection, specifically with respect to the analogous art doctrine.  In Netflix, Inc. v. DivX, LLC,

[1] the Patent Trial and Appeal Board (PTAB or Board) sided with the patentee DivX, holding that a key secondary prior art reference was not analogous art.  On appeal, the Federal Circuit partially affirmed, but vacated and remanded the case back to the Board on a procedural issue.   Of note, the Federal Circuit has clarified how strictly the requirements of the two-prong test for non-analogous art must be met.

DivX’s patent relates to encoding, transmitting, and decoding multimedia files to enable “trick play” functionality, such as rewinding or fast forwarding to a particular part of a streaming video.  Netflix filed a petition for Inter Partes Review (IPR), asserting that the patent was unpatentable under 35 U.S.C. § 103 for obviousness over a combination of two prior art references.  At issue in this case is the secondary reference which describes using AVI files and index chunks to reproduce motion images in digital cameras.  A key issue in the IPR focused on whether the secondary reference qualifies as analogous art with respect to DivX’s patent.  In other words, the question was whether a reference generally relating to the field of digital cameras is analogous art regarding a patent in the field of streaming video.   

A reference is considered to be analogous art if either one of the following is met: (1) it is from the same field of endeavor as the claimed invention; or (2) if it is not in the same field of endeavor, then it is reasonably pertinent to the particular problem with which the inventor is involved.  The idea behind the first prong of this doctrine is to limit the art that can be used to reject claims of a patent application to documents that a hypothetical person of ordinary skill in the art would actually look to in arriving at the claimed invention.  On the other hand, the second prong disregards prior art that is not only in a different field of endeavor, but also has a different purpose or solves a different problem altogether than that of the invention.  In the combination of such circumstances, a person of ordinary skill in the art would not be expecting to be aware of such a disclosure.

In discussing generally the backgrounds of DivX’s challenged patent and the prior art references, IPR petitioner Netflix did not explicitly state the field of endeavor using the exact words “the field of endeavor is AVI files,” or “the problem that the patent is pertinent to is [the claimed invention].”  However, Netflix did broadly address the general field to which the secondary reference is directed on multiple occasions in its IPR briefs, even mentioning that the secondary reference relates to encoding/decoding multimedia files, which is exactly what the background section of the challenged patent’s specification mentions as being the field of the invention. 

Ultimately, the Federal Circuit decided that the PTAB took an unreasonably rigid approach as to how explicitly the field of endeavor must be articulated, reasoning that Netflix merely pointed to broad fields “known in the art” in the alternative, rather than specifically addressing “the problem that DivX’s patent seeks to solve.”  The CAFC held that there are no “magic words” required to establish a field of endeavor of either the secondary prior art reference or the patent being challenged on the ground of obviousness over a combination of primary and secondary references.  However, the CAFC did affirm the Board’s factual finding that the secondary reference was not reasonably pertinent to the challenged patent’s problem of facilitating trick play in streaming multimedia, because the reference addressed a different problem of memory limitations in digital cameras. 

Non-analogous art arguments, while historically difficult, seem to be gaining more traction recently. In the event practitioners thought it was an uncommon and seldom convincing argument, the Federal Circuit in Netflix has made it less cumbersome to show when art is non-analogous under the long-standing two-part test.    



[1] No. 22-1138, 2023 WL 3115576 (Fed. Cir. Sept. 11, 2023).