This is Part III of my series on the relevance of the invention date in patent prosecution. You may download my entire paper here. This part considers the role of provisional patent applications as an incomplete but functional substitute for invention-date rights.
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With some caveats, I argue that provisional patent applications can serve as functional substitutes for reliance on the U.S. filing grace period. Provisional patent applications have become popular since being made available in 1995. The USPTO reports that applicants filed 143,030 provisional patent applications in fiscal year (“FY”) 2008, compared with 466,147 non-provisional utility applications that year. U.S. applicants file a great majority of these provisional applications Consequently, the provisional filings correspond to more than half of the annual total of utility applications filed by U.S. residents.
A provisional application is essentially a low-cost placeholder that allows an applicant to establish a priority date by filing a description of the invention along with paying an administrative fee to the USPTO. The applicant may later file a non-provisional application claiming the benefit of the provisional application’s filing date. The provisional patent application has a twelve-month non-extendable pendency. During that time-period, the application is kept secret and is not examined. Thus, to rely upon the provisional priority date, the applicant must submit a non-provisional application within one year of the provisional filing date. Professor Seymore notes several additional strategic advantages of filing provisional patent applications: “extending the patent term to twenty-one years, postponing the examination period, trolling for prior art, and avoiding an allegation of inequitable conduct.”
To explore the relevance of provisional patent applications as a tool for claiming priority, I created a dataset of 5000+ provisional patent applications filed between January 1, 2001 and October 1, 2007. Of those, over half (52%) were still secrete as not yet identified in the priority claim of any publicly available non-provisional application. Although some of these will eventually become public as associated with a non-provisional filing, in the end, close to 40% or more of the provisional application filings will never be linked to an issued patent or public non-provisional application. Collectively, these figures indicate that a large number of provisional applications are themselves left floundering to be abandoned twelve months after filing. The large number of abandoned provisional applications suggests to me that provisional patent applications are likely being used as early place-holders to cheaply secure a priority date, rather than as a means of extending the patent term or postponing examination. In a separate study looking at the 620,000+ issued patents for which applications were filed between 2000 and 2005, I found that seventeen (17) percent of the patents in the data-set claim priority to at least one provisional application. On average, the patents claiming priority listed 1.4 provisional patent applications. In a separate study, I found that on average abandoned non-provisional applications tended to claim priority to 2.0 provisional patent applications. This combining of multiple provisional applications to support a single patent supports this theory that provisional applications as a substitute for filing date evidence. Notably, each provisional can serve as evidence of an incremental advance in place of a corroborated laboratory notebook. Anecdotal reports suggest that this practice has become especially prevalent among universities developing early stage innovations. However, the value of incremental provisional application filings is limited by the hard twelve-month deadline for filing a non-provisional application.
For an inventor who has conceived a new invention, the legal benefits of filing a provisional application, rather than relying on the invention date, are compelling. If the filing deadlines are met, a provisional patent application will serve as conclusive evidence of priority—without any need for any affidavits or declarations—so long as the provisional application discloses the invention claimed in the non-provisional application “in the manner provided by the first paragraph of section 112.” In other words, the specification of the provisional application must “contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable” an ordinarily skilled artisan to practice the invention claimed in the non-provisional application.
Unlike an applicant seeking to assert a prior invention date, an applicant claiming priority to a provisional application need not provide corroborated evidence—or indeed any evidence—of actual reduction to practice, conception date, or reasonable diligence in working toward reduction to practice. Rather, the USPTO and courts treat the filing of a provisional patent application as a constructive reduction to practice, thus allowing the applicant to rely on the simple evidence of the paper filing.
An oft-stated disadvantage of provisional application filings is that they may create a false sense of security among patent applicants. Certainly, a hastily-filed provisional patent application may fail to properly describe the invention to be claimed in a later-filed non-provisional application. However, the validity of this criticism does not suggest that applicants should merely rely upon the hope that they will possess sufficient evidence to antedate references based on a prior invention date. Rather, risk-averse applicants should quickly file a well supported application either in provisional or nonprovisional form.