Chapter §5.02 Best Mode as Enablement-Plus

• Jurisdiction: United States

§5.02 Best Mode as Enablement-Plus

The best mode requirement of 35 U.S.C. §112, ¶1, implements an enablement-plus criterion. Under U.S. patent law, it is not enough that an applicant has merely disclosed one way of making and using the invention; he bears a further obligation to disclose the best way known to him on the application filing date of "carrying out [the] invention."¹⁰ As explained by the Federal Circuit, the difference between the enablement and best mode requirements is that

[e]nablement looks to placing the subject matter of the claims generally in the possession of the public. If, however, the applicant develops specific instrumentalities or techniques which are recognized at the time of filing as the best way of carrying out the invention, then the best mode requirement imposes an obligation to disclose that information to the public as well. ¹¹

The U.S. Court of Appeals for the Federal Circuit considers compliance with the best mode requirement a question of fact.¹² In contrast with enablement, best mode includes a subjective component. The court has explained that although "[t]he enablement requirement . . . looks to the objective knowledge of one of ordinary skill in the art, . . . the best mode inquiry is a subjective, factual one, looking to the state of the mind of the inventor."¹³

As a factual inquiry, the ultimate question of best mode compliance is reviewed for clear error on appeal from a bench trial or under the substantial evidence standard on appeal from a jury verdict.¹⁴ In contrast, the ultimate question of enablement is treated as a question of law, reviewed de novo.¹⁵ Best mode, like enablement, contemplates subsidiary factual determinations, as detailed infra.¹⁶

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Notes:

^[10] 35 U.S.C.A. §112(a) (effective Sept. 16, 2012) provides that, in addition to an enabling disclosure and a written description of the invention, the specification "shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention."

^[11] Spectra-Physics, Inc. v. Coherent, Inc., 827 F.2d 1524, 1532 (Fed. Cir. 1987); see also Ariad Pharms., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1347 (Fed. Cir. 2010) (quoting Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 736 (2002) (concluding that §112 has three separate requirements: "[T]he patent application must describe, enable, and set forth the best mode of carrying out the invention.") (emphasis in original)); Bayer AG & Bayer Corp. v. Schein...