The More Things Change, the More They Stay the Same: Implications of Pfaff V. Wells Electronics, Inc. and the Quest for Predictability in the On-Sale Bar

60 Pages Posted: 14 Nov 2010

Date Written: July 15, 2000


Section 102(b) of Title 35 precludes an inventor from receiving a patent if the invention was on sale in the United States more than one year prior to filing a patent application. The statutory structure of the on-sale bar has left the term "invention" ill-defined, leading to considerable uncertainty in the courts. Hoping to add predictability to this unsettled area of law, the Supreme Court in Pfaff v. Wells Electronics, Inc. articulated a new standard that requires an invention be "ready for patenting" in order for the bar to apply.

This new test, as applied by the lower courts, has effected no real change in the law as district courts are diverging significantly from the Supreme Court’s test and holding that the offer for sale of the mere conception of the invention is sufficient for the bar to apply. The courts also have conflated the two versions of the on-sale bar: the anticipatory version, where what is offered for sale is precisely the same as what is later claimed in the patent, and the obviousness version, where what is offered for sale varies from what is later claimed, but that variation would be obvious to one skilled in the relevant technological art. This approach further undermines predictability and the other policies that underlie the on-sale bar.

This article posits a two prong approach to the on-sale bar. First, for the anticipatory version, the courts should expressly incorporate the law of enablement under 35 U.S.C. § 112 and of utility under 35 U.S.C. § 101 into the on-sale bar, thus providing a well-known body of law to promote predictability. Procedurally, the courts should establish a hierarchy of evidence, similar to the approach used in claim construction, that considers certain, more readily available information as the most pertinent while eschewing the use of expert testimony and other litigation-based evidence. Second, for the obviousness version of the on-sale bar, there should not be a "ready for patenting" test. Instead, whatever is offered for sale should be considered within the public knowledge and useable to determine whether the inventor has claimed something more than a simple variation of what she offered for sale. This approach would better serve the policies underlying the on-sale bar and comports more readily with the concepts of "prior art" in patent law without impeding the predictability sought in this area.

Keywords: Patent, pfaff, on sale bar, invalidity, reduction to practice, conception, obviousness

Suggested Citation

Holbrook, Timothy Richard, The More Things Change, the More They Stay the Same: Implications of Pfaff V. Wells Electronics, Inc. and the Quest for Predictability in the On-Sale Bar (July 15, 2000). Berkeley Technology Law Journal, Vol. 15, No. 933, 2000. Available at SSRN:

Timothy Richard Holbrook (Contact Author)

Emory University ( email )

1301 Clifton Road
Atlanta, GA 30322
United States
404-712-0353 (Phone)

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