Scope of "Printed Publication" Category of Prior Art Expanded

January 13, 2014

Thomas A. Franklin

What This Means To You

  • Consider all forms of printed material as potential prior art when trying to invalidate a patent.
  • Use signed statements from those with firsthand knowledge of the distribution of a printed document to establish public accessibility.
  • An item qualifies as a “printed publication” if it was publicly accessible and members of the relevant public had access to it.


In Re Enhanced Security Research LLC is a significant court decision because it represents an apparent expansion of the interpretation by the U.S. Court of Appeals for the Federal Circuit (Federal Circuit) of the “printed publication” form of prior art. Namely, the Federal Circuit holds that a printed document need not be indexed or actively ditributed to qualify as a prior art printed publication.

Case Background

The case involves an appeal by Enhanced Security Research (ESR) from an ex parte reexamination by the Board of Patent Appeals and Interferences (the “Board”) relating to its patent covering a computer security device. The Board had found the patent invalid as being obvious over a combination of two references, one of which was a manual for a software product. The Board had considered the manual to be a prior art “printed publication” within the meaning of the patent statute.

On appeal to the Federal Circuit, ESR challenged the manual’s status as prior art. Decision Analysis

Decision Analysis

The Federal Circuit concluded that the Board had not erred in treating the manual as a printed publication and therefore as prior art.

When considering whether an item qualifies as a “printed publication” within the meaning of the statute, the inquiry centers around whether the item was publicly accessible and, in particular, whether members of the relevant public had access to the item. For example, one of the Court’s leading cases on the issue had previously established that documents indexed in a library can satisfy the requirement of being publicly accessible.

During the Board’s reexamination, evidence was submitted showing that the software product to which the manual corresponded had been advertised to members of the relevant public, and that the manual was available to such individuals upon request if an interest was shown in the software product itself. The evidence included a signed statement from the CEO of the company which manufactured the software product. The Federal Circuit found this evidence sufficient to conclude that the manual itself was publicly accessible and therefore prior art.


The Federal Circuit’s decision in this case raises the possibility that documents and other printed items can qualify as printed publication prior art even if not indexed or catalogued. Thus, when searching for prior art to invalidate a patent, such documents should not be ignored.

That said, the analysis is highly fact specific, focusing on the manner in which the document was accessible to the public. Thus, to the extent possible, obtaining signed statements from those with firsthand knowledge of the distribution of a document can be critical in establishing its public accessibility.