Patents, Presumptions, and Public Notice

48 Pages Posted: 1 Aug 2010 Last revised: 12 Jun 2012

See all articles by Timothy R. Holbrook

Timothy R. Holbrook

University of Denver Sturm College of Law

Date Written: July 31, 2010


Patents are peculiar legal instruments in that they contain both technical and legal information. This Janus-like nature of the document is important because they serve the legal purpose of affording the owner the right to exclude others from practicing the invention, and third parties need to be able to assess the scope of that right. At the same time, through the patent’s disclosure, the document is intended to contribute to the storehouse of technical knowledge. Superficially, patents are generally viewed through the eyes of the hypothetical person of ordinary skill in the art (PHOSITA), patent law’s “reasonable person.” Unfortunately, the U.S. Court of Appeals for the Federal Circuit has marginalized the PHOSITA by treating the document, particularly in claim construction and in assessing the sufficiency of the patent’s disclosure, as a purely legal document. While this shift is understandable, it is also unfortunate. Possible justifications for the court’s move are unpersuasive. For instance, from the ex ante perspective, the court may hope to encourage future applicants to provide better disclosures. As this Article explains, that argument fails because the court’s legal standards are too vague and the lapse of time between the application and a competitor’s review of the patent causes informational asymmetries for which the applicant cannot account. A second temporal problem arises because the Federal Circuit is setting the standard primarily through litigation. By the time of litigation, however, current technologies have shifted, altering the nature of the required disclosures in current applications. As a result, the court is offering the standard for old technologies, too late for current applications, with the cost of invalidating extant patents. From an ex post perspective, this shift may assist lay-judges and juries in evaluating patents, but such a result is the problem - this treatment reduces the technical value of the patent and incentivizes future applicants to treat the disclosure in a legal fashion, not as a technical resource.

To balance the interest in public notice with the technical nature of the patent, this Article posits the use of presumptions. Courts should use the intrinsic evidence - the patent and the prosecution history - to generate a presumptive conclusion as to the construction of the patent or the sufficiency of the patent’s disclosure. Then, the court should resort to the extrinsic evidence to determine whether the legalistic conclusion reached should be rejected in light of the understanding of technologists in the relevant field. In this way, the default position for courts is interpretation afforded by the intrinsic record, enhancing public notice. This default, however, can be rebutted when facts regarding the technical import of the document are brought to bear, bringing the viewpoint of the PHOSITA into the calculus.

Keywords: patent, written description, claim construction, enablement, presumptions, PHOSITA, default, penalty default

Suggested Citation

Holbrook, Timothy Richard, Patents, Presumptions, and Public Notice (July 31, 2010). Indiana Law Journal, Vol. 86, p. 779, Summer 2011, Emory Law and Economics Research Paper No. 10-71, Emory Public Law Research Paper No. 10-112, Available at SSRN:

Timothy Richard Holbrook (Contact Author)

University of Denver Sturm College of Law ( email )

2255 E. Evans Avenue
Denver, CO 80210
United States


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