When patent examiners examine patent applications, they will look at whether there exists certain prior art in related field to decide whether the patent application is novel.  Novelty is one of the requirements a patent application must meet in order to become a valid patent.  It is important for practitioners to understand the standard for determining a legitimate prior art, in order to evaluate the chances of winning a patent infringement dispute.

A recent Federal Circuit case, In re Giacomini, 2010 U.S. App. LEXIS 13804 (Fed. Cir. July 7, 2010), extended the scope of the secret prior art defined in 35 U.S.C. 102 (e).  A secret prior art means a prior art filed before but published after the subject patent application is filed.  Under the decision, a US patent or published application will be considered prior art as of the filing date of its qualifying provisional application.  In this case, the Federal Circuit held that, agreeing with USPTO’s position, when a provisional application is used as a prior art, the filing date is the 102(e) priority date, rather than the actual filing date of the later formal application.

35 U.S.C. 102(e)(2), bars the patentability if the invention was described in a patent granted on an application for patent by another filed in the United States before the invention by the applicant for patent.  Giacomini’s patent application was first filed on Nov. 29, 2000 and the USPTO examiner found a prior art, U.S. patent 7,039,683 (the “Tran Patent”), against Giacomini’s patent application.   The Tran Patent was filed in December 2000 (after Giacomini) and issued in 2006. However, the USPTO asserted that the patent should be considered as a 102(e) prior art because it claims priority to a U.S. provisional application that was filed in September 2000.

In a prior case, In re Klesper, 397 F.2d 882 (C.C.P.A. 1968), the United States Court of Customs and Patent Appeals (CCPA, the  Federal Circuit’s predecessor court) held that the 102(e) follows the prior precedent of treating a prior art disclosure found in an issued patent as being disclosed as of the “filing date of the earliest U.S. application to which the patent is entitled, provided the disclosure was contained in substance in the said earliest application.”  The Federal Circuit agreed that this provision applies equally to provisional patent applications.  Thus, the Tran Patent shall have the same patent-defeating effect as to the claimed invention as though it was filed on the date of the Tran Patent’s provisional application.

Patent practitioners should be aware of this current development while conducting their prior art search.  Provisional applications could be another source of legitimate prior arts, and should not be overlooked.