“Public Use” and “Publication” of an Invention can Potentially Bar Patent Protection. So, How are These Terms Defined?
February 24, 2025

Written by: Charles Dresser
Patent protection is prohibited for inventions which have been (1) in public use; or (2) published more than a year before the patent application filing date. 35 U.S.C. § 102. But how are these two circumstances defined under the law?
The Intellectual Property (IP) Clause of the U.S. Constitution allows Congress to create laws that grant patents to “[p]romote the progress of Science and the Useful Arts.” Courts have defined the terms “public use” and “publication” consistent with this constitutionally mandated policy goal of promoting the progress of science and the useful arts.
The definition of “public use” includes uses which are made in public, and may be non-enabling. See The Corset Case (court held that the wearing of an inventive bra—under clothes— in public was public use in spite of only being know to the wearer). Accordingly, an inventor may not benefit from his invention in public for years and then seek a patent later. This policy requires an inventor to share his disclosure with the patent office—and ultimately the public—before using and benefiting from the invention in public; thereby incentivizing the progress of science and the useful arts through invention disclosure.
“Publication” requires that the publication be made accessible to people with the relevant technical understanding (i.e., those of ordinary skill in the art). The publication need not be accessed by a person of ordinary skill in the art, just accessible to a person of ordinary skill in the art. Like that of “in public use,” the definition of “publication” is consistent with the policy goal that patents promote progress of science and the useful arts. To promote progress of science and the useful arts, Congress grants a limited-term monopoly on inventions in exchange for their initial public disclosure. Courts have decided that once the invention is accessible to those component to practice an invention, public disclosure has (already) occurred and the inventor can no longer exchange initial public disclosure for a patent.