To Agree, or Not to Agree: That Is the Question when Evaluating the Best Mode Preferences of Joint Inventors After Pannu v. Iolab Corp. – Note by Melissa N. McDonough

From Volume 80, Number 1 (November 2006)

One of the many requirements for patentability is that the inventor must disclose the “best mode” of the invention. This requirement is set out in the first paragraph of 35 U.S.C. § 112, which states that the patent’s specification “shall set forth the best mode contemplated by the inventor of carrying out his invention.” Based on the statutory language, the test for whether the best mode has been properly disclosed has a subjective element – whether or not the inventor believed that there was a best way to practice the invention at the time the patent application was filed. If the inventor believed that a certain method of practicing the invention was better than other methods, the inventor had to disclose that mode. If the inventor did not have a preferred method of practicing the invention, then there was no best mode to be disclosed.

At first, the test seems fairly straightforward. An inventor either had a preferred mode at the time of filing, or the inventor did not. The test becomes far more complicated, however, when the involvement of more than one inventor requires the consideration of multiple opinions. For example, what happens if there are two inventors and they disagree as to what is the best mode? Whose view controls and which mode or modes must be disclosed? In a case of joint inventorship where each inventor works on different parts of an invention, what happens when an inventor who did not work on a certain part prefers a best mode for that part, and that preference is not shared by the person who actually invented it? If a joint inventor is accidentally omitted from a patent, and the omitted inventor had a best mode preference that was not disclosed at the time of the application’s filing, should the patent be invalidated for failure to disclose that mode when the omitted inventor is added to the patent later? These are all questions that are critical to best mode analysis, as patent infringers currently are able to use the best mode requirement as a weapon to invalidate patents in litigation. And in order to answer these questions effectively, it is increasingly important to understand how the ease of establishing joint inventorship under the current statutory framework affects best mode analysis. Unfortunately, the Federal Circuit neglected to consider the impact of liberalized joint inventorship principles in Pannu v. Iolab Corp., where, in a footnote in dicta near the end of the opinion, the court appeared to set a standard that required any joint inventor who has a best mode preference for any claim to disclose it.