Under the American legal avenues for patent registration, administered by the United States Patent and Trademark Office
Interference proceedings are unique in patent registration procedures to the legal culture of the United States. The American legal system understands patent registration rights as the property of the inventor at the moment that the conception for some new device or process is “reduced” to practice, or materially implemented.
According to the Federal Circuit Court opinion on the case of Hybridtech vs. Monoclonal Antibodies, Inc., in 1986, conception can be defined as the “formation in the mind of the inventor, of a definite and permanent idea of the complete and operative invention, as it is hereafter to be applied in practice.” For this reason, the United States is considered to have a first-to-invent system for patent registration, in contrast to which most countries, such as in Europe, operate according to a first-to-file system.
The practical utility of the reduction to practice concept for inventors is to allow them to block patent registration of a device or process they came up with but failed to file before another individual had the chance to do so. The interference proceeding is the technical means though which this end is achieved.
For the purpose of an interference proceeding, there are several different forms in which reduction to practice may be understood to have occurred. The most conventional, in that the American system is still geared toward patent registration through official documentation, is referred to as constructive reduction to practice. According to the Federal Circuit opinion on the 1995 case of Brunswick Corp. vs. U.S., this happens with “the filing of a patent application on the claimed invention.”
For inventors who made use of a process or device before submitting it to patent registration, a case of “actual reduction to practice” will be applied instead by the interference proceeding. In deciding on interference proceedings, United States courts will also consider “simultaneous conception and reduction to practice” as a principle, particularly in reference to discoveries made in areas with volatile elements such as biology.
In cases coming under this heading, inventors are unable to conceive of the invention until they have practically implemented it.
Some of the means by which an instance of “actual reduction to practice” can be applied to a patent registration case include several different forms of evidence that may be referred to by the court. The most common kind of evidence cited in an interference proceeding is the “inventor’s notebook.” Another is a working model of the invention.