The 'best mode requirement' in the United States is an additional requirement complementing the 'sufficiency of disclosure' requirement. That is, the disclosure must also contain the inventor's "best mode" of making or practicing the invention. The "best mode requirement" only applies to what the inventor knows at the time the application was filed, not as to what was subsequently discovered.
"The best mode requirement creates a statutory bargained-for-exchange by which a patentee obtains the right to exclude others from practicing the claimed invention for a certain time period, and the public receives knowledge of the preferred embodiments for practicing the claimed invention." Eli Lilly & Co v. Barr Laboratories Inc, 251 F.3d 955, 963, 58 USPQ2d 1865, 1874 (Fed.Cir.2001).
The best mode requirement is a safeguard against the desire on the part of some people to obtain patent protection without making a full disclosure as required by the statute. The best mode requirement does not permit inventors to disclose only what they know to be their second-best embodiment, while retaining the best for themselves. In re Nelson, 280 F.2d 172, 126 USPQ 242 (CCPA 1960).
Determining compliance with the best mode requirement requires a two-prong inquiry. First, it must be determined whether, at the time the application was filed, the inventor possessed a best mode for practicing the invention. This is a subjective inquiry which focuses on the inventor's state of mind at the time of filing. Second, if the inventor did possess a best mode, it must be determined whether the written description disclosed the best mode such that a person skilled in the art could practice it. This is an objective inquiry, focusing on the scope of the claimed invention and the level of skill in the art. Eli Lilly & Co. v. Barr Laboratories Inc., 251 F.3d 955, 963, 58 USPQ2d 1865, 1874 (Fed. Cir. 2001).
Where an inventor knows of a specific material that will
make possible the successful reproduction of the effects claimed by the patent, but does
not disclose it, speaking instead in terms of broad categories, the best mode requirement
has not been satisfied. Union Carbide Corp. v. Borg-Warner, 550 F.2d 555, 193 USPQ 1 (6th
Northern Telecom Ltd. v. Samsung Electronics Co., 215 F.3d 1281, 55 USPQ2d 1065 (Fed. Cir. 2000) - Unclaimed matter that is unrelated to the operation of the claimed invention does not trigger the best mode requirement.
Eli Lilly & Co. v. Barr Laboratories Inc., 251 F.3d
955, 966, 58 USPQ2d 1865, 1877 (Fed. Cir. 2001) - Patentee's failure to disclose an
unclaimed preferred mode for accomplishing a routine detail does not violate best mode
requirement because one skilled in the art is aware of alternative means for accomplishing
the routine detail that would still produce the best mode of the claimed invention.
2165.02 Best Mode Requirement Compared to Enablement Requirement
The best mode requirement is a separate and distinct requirement from the enablement requirement of the first paragraph of 35 U.S.C. 112. In re Newton, 414 F.2d 1400, 163 USPQ 34 (CCPA 1969).
The enablement requirement 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 by the applicant 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. Spectra-Physics, Inc. v. Coherent, Inc., 827 F.2d 1524, 3 USPQ 2d 1737 (Fed. Cir.), cert. denied, 484 U.S. 954 (1987).
BEST MODE REQUIREMENT SATISFIED - EXAMPLES
In one case, even though the inventor had more information in his possession concerning
the contemplated best mode than was disclosed (a known computer program) the specification
was held to delineate the best mode in a manner sufficient to require only the application
of routine skill to produce a workable digital computer program. In re Sherwood, 613 F.2d
809, 204 USPQ 537 (CCPA 1980).
There was held to be no violation of the best mode requirement even though the inventor did not disclose the only mode of calculating the stretch rate for plastic rods that he used because that mode would have been employed by those of ordinary skill in the art at the time the application was filed. W.L. Gore & Assoc., Inc. v. Garlock Inc., 721 F.2d 1540, 220 USPQ 303 (Fed. Cir. 1983).
High Concrete Structures Inc. v. New Enter. Stone & Lime Co., 377 F.3d 1379, 1384, 71 USPQ2d 1948, 1951 (Fed. Cir. 2004). The unintentional failure to disclose in the specification the use of a crane to support the patented frame in order to carry out the method of loading and tilting the frame was held not to defeat the best mode requirement because one of ordinary skill in the art would understand and use a crane to move heavy loads. "The best mode requirement of [35 U.S.C.] § 112 is not violated by unintentional omission of information that would be readily known to persons in the field of the invention."
Where an organism was created by the insertion of genetic material into a cell obtained from generally available sources, all that was required to satisfy the best mode requirement was an adequate description of the means for carrying out the invention, not deposit of the cells. As to the observation that no scientist could ever duplicate exactly the cell used by applicants, the court observed that the issue is whether the disclosure is adequate, not that an exact duplication is necessary. Amgen, Inc. v. Chugai Pharmaceutical Co., 927 F.2d 1200, 18 USPQ 2d 1016 (Fed. Cir. 1991).
The court concluded that no withholding could be inferred from general statements of increased selectivity and narrower spectrum of potency for these novel analogs, conclusions which could be drawn from the elementary pharmacological testing of the analogs. In re Bundy, 642 F.2d 430, 435, 209 USPQ 48, 52 (CCPA 1981).
The best mode requirement was held to be violated where inventors of a laser failed to
disclose details of their preferred TiCuSil brazing method which were not contained in the
prior art and were contrary to criteria for the use of TiCuSil as contained in the
literature. Spectra-Physics, Inc. v. Coherent, Inc., 827 F.2d 1524, 3 USPQ 2d 1737 (Fed.
The best mode requirement was violated because an inventor failed to disclose whether to use a specific surface treatment that he knew was necessary to the satisfactory performance of his invention, even though how to perform the treatment itself was known in the art. The argument that the best mode requirement may be met solely by reference to what was known in the prior art was rejected as incorrect. Dana Corp. v. IPC Ltd. Partnership, 860 F.2d 415, 8 USPQ2d 1692 (Fed. Cir. 1988).