Pfaff v. Wells Electronics, Inc.
525 U.S. 55 (1998)
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Rule of Law:
The one-year on-sale bar under 35 U.S.C. § 102(b) applies when an invention is both the subject of a commercial offer for sale and is ready for patenting. An invention is ready for patenting if it has been reduced to practice or if the inventor has prepared drawings or descriptions sufficiently specific to enable a person skilled in the art to practice the invention.
Facts:
- In November 1980, Texas Instruments asked Wayne Pfaff to develop a new computer chip socket.
- In response, Pfaff prepared detailed engineering drawings that described the design, dimensions, and materials for the socket.
- Pfaff sent these drawings to a manufacturer in February or March 1981.
- On April 8, 1981, Texas Instruments provided Pfaff with a written confirmation of a purchase order for 30,100 sockets for a total of $91,155.
- Pfaff did not construct or test a physical prototype of the socket before accepting the purchase order.
- The manufacturer did not successfully produce the sockets and fill the order until July 1981.
- Pfaff filed an application for a patent on the socket on April 19, 1982.
Procedural Posture:
- Pfaff filed a patent infringement suit against Wells Electronics, Inc. in U.S. District Court.
- Following a hearing before a Special Master, the District Court rejected Wells' on-sale bar defense, finding the patent claims valid because Pfaff filed his application less than a year after the invention was reduced to practice.
- Wells Electronics, Inc. (appellant) appealed the District Court's decision to the U.S. Court of Appeals for the Federal Circuit.
- The Court of Appeals reversed, holding that the patent claims were invalid under the on-sale bar because the invention was 'substantially complete' at the time of the sale, even if not reduced to practice.
- Pfaff (petitioner) petitioned the U.S. Supreme Court for a writ of certiorari, which was granted.
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Issue:
Does the one-year on-sale bar of 35 U.S.C. § 102(b) begin to run when an invention is commercially offered for sale, even if the invention has not yet been reduced to practice?
Opinions:
Majority - Justice Stevens
Yes. The on-sale bar under 35 U.S.C. § 102(b) can be triggered before an invention has been reduced to practice. The Court rejected the Federal Circuit's 'substantially complete' test and established a new two-part test. The on-sale bar applies if, before the critical date (one year prior to the patent application filing), two conditions are met: (1) the product is the subject of a commercial offer for sale, and (2) the invention is ready for patenting. An invention is 'ready for patenting' either by proof of reduction to practice or by proof that the inventor had prepared drawings or other descriptions sufficiently specific to enable a person skilled in the art to practice the invention. In this case, Pfaff made a commercial offer to Texas Instruments before the critical date of April 19, 1981. Furthermore, his detailed engineering drawings, which he provided to the manufacturer, were sufficient to enable the production of the socket, proving the invention was ready for patenting at the time of the sale. Therefore, because both conditions were met more than one year before he filed his patent application, his patent is invalid.
Analysis:
This case significantly clarified the 'on-sale bar' doctrine in U.S. patent law, providing a more definite and predictable standard for inventors. By replacing the vague 'totality of the circumstances' and 'substantially complete' tests with a clear two-part framework, the Court reduced uncertainty about when the one-year clock for filing a patent application begins. The decision emphasizes that the concept of an 'invention' is tied to its complete conception and description, not necessarily its physical embodiment. This ruling forces inventors to be diligent in filing for patent protection once they begin commercializing an invention, even if it only exists in detailed schematic form.
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