The following article appears in the journal JOM, 46 (12) (1994), p. 61. JOM is a publication of The Minerals, Metals & Materials Society

Best Mode Disclosure—Comply or Invalidate Your Patent

The United States patent system provides the inventor with a period of exclusivity during which the inventor has the right to prevent others from making, using, or selling the invention. In return, the public receives a free right to practice the invention after the patent expires.

In order to make sure that patents are self-speaking and enable the public to practice the invention, the patent statute establishes certain disclosure requirements. More specifically, the patent application must provide a detailed description of the invention and of the manner of making and using it in such full, clear, concise, and exact terms that any person skilled in the art to which the patent pertains can make and use the same. This portion of the statute, which is generally described as the "enablement provision," has been interpreted as requiring the inventor to provide a sufficiently detailed disclosure so that someone skilled in the art can practice the invention without undue experimentation. A second and distinct requirement of the statute is that the specification must "set forth the best mode contemplated by the inventor of carrying out his invention."

Because a patent can be invalidated for failure to comply with either of these standards, both must receive careful attention during the preparation of a patent application. For example, an inventor could provide an enabling disclosure while withholding the "best mode" of practicing the invention. Frequently inventors are tempted to withhold key elements that contribute meaningfully to the most advantageous practice of the invention while seeking the full benefit of the patent system. This is not only an undesirable practice, but can result in the patent being invalidated.

The best mode requirement focuses specifically on the best mode known to the inventor at the time the application is filed. It is a subjective standard. Suppose that the inventor faced with options A, B, and C with respect to a particular feature of the invention concludes at the time of filing that application A is the best mode. If it is subsequently determined that either B or C is in fact a better mode, this will not jeopardize the validity of the patent since the inventor has, in good faith, provided information to the best of his or her knowledge at the filing date.

While the concept of "best mode" will generally be interpreted as referring to what is technically best, this will not always be the case. For example, suppose the inventor recognizes that the best performance technically might be achieved by making a given component out of gold, silver, or platinum, but realizes that the cost of such a component would be unrealistic and, as a result, that approach would never be adopted commercially. It would be appropriate for the inventor to mention that the best mode would involve the manufacture of a component of aluminum or steel as being a technically satisfactory and economically practical material.

Since the best mode test is a subjective one, the inventor is not required to be an expert in the field, to perform extensive research to ascertain the best mode, or to understand how the invention works. Such credentials and activities are not otherwise required by the patent system, and the best mode requirement does not add a requirement of this type. All that is required is that the inventor fully share his or her state of knowledge on the issue as of the filing date. The inventor merely needs to teach another how to practice the invention through an appropriate enabling disclosure that complies with the best mode requirement.

The nature of the technology and complexity of the invention can have a significant influence on how much an inventor must disclose in order to satisfy the best mode requirement. There is no need to clutter a patent application with words and drawings that disclose details that would be well known to those skilled in the art. For example, if a set screw is employed in the invention, it is not necessary to state that a screwdriver should be employed to adjust the position of the screw. When in doubt, however, it is best to err in the direction of providing too much information rather than too little.

An inventor might conclude that any of a group of solvents usable in the invention would perform equally well. It is not necessary for the inventor to make a judgment call and select a specific solvent. The inventor might state that the best mode of practicing the invention involves using a solvent selected from the group consisting of X, Y, and Z. Alternatively, the inventor might describe the solvent according to the desired properties found in solvents that give the best performance.

In general, the best practice is for the inventor to provide a full disclosure to the patent attorney and for the two of them to make decisions regarding what should be disclosed in the application in order to make sure that there has been compliance with the best mode requirement. All decisions must be handled on a case-by-case basis. It is of utmost importance that the inventor act in good faith and direct attention to the best mode requirement.

If this evaluation of the best mode is handled on a good faith basis with full disclosure of the inventor's state of knowledge at the time the application is filed, changes in the invention subsequent to the filing of the patent application are irrelevant to this issue.

In summary, honesty and good faith are the key elements required to avoid a challenge to validity of any resultant patent based upon failure to comply with this standard.