Intellectual Property Office

Legal Requirements for Inventorship

The U.S. Patent Act specifies that a U.S. patent application must be filed in the name of the inventor(s) of the invention that is recited in the claims.  Filing an application in the name of someone who is not an inventor of the claimed invention, or omitting someone who should be listed as an inventor, can result in a finding of invalidity of the patent that ultimately issues.

An invention is the result of a two-step process, namely, conception and reduction to practice.  Conception itself, however, is the touchstone of inventorship.  Conception is defined as "the formation in the mind of a definite and permanent idea of the complete operative invention and method of obtaining it" such that one of ordinary skill in the pertinent art could practice the invention without extensive research or experimentation.  An inventor does not need to know his invention will work for conception to be complete.

A joint invention connotes collaboration of effort to produce a complete and operative invention, and one who merely suggests the idea of a result to be accomplished, rather than a means of accomplishing it, is not a joint inventor.  Accordingly, where the invention arose from discussions among several individuals, one may influence the inventive process without making a contribution that rises to the level of inventorship.

A joint inventor must: (1) contribute in some significant manner to the conception of reduction to practice of the invention, (2) make a contribution to the claimed invention that is not insignificant in quality, when that contribution is measured against the dimension of the full invention, and (3) do more than merely explain to the actual inventors well-known concepts and/or the current state of the art.

Reduction to Practice, on the other hand, relates to the making and testing of an invention in order to ensure that it will work for its intended purpose, referred to as an "actual" reduction to practice.  Reduction to practice may also be "constructive."  This occurs where a patent application supported by an enabling disclosure is filed with the United States Patent and Trademark Office ("USPTO").

Under the law, an individual who contributes to the reduction to practice of the invention defined in the claims but not the conception of the invention is not an inventor.  This is the case even where the reduction to practice is the most time consuming or difficult part of the inventive process.

In sum, the federal courts have consistently held that an individual does not qualify for inventorship status where that person: (a) contributed an obvious element to the invention (or an element that is in the public domain), (b) researched and explained the state of existing art to the inventor, (c) suggested an idea without also providing a way to implement the idea, (d) followed instructions of and experiments designed by another, or (e) participated in consultations about the invention before or after conception of the invention.