Parker v. Flook

Parker v. Flook
Supreme Court of the United States
Argued April 25, 1978 Decided June 22, 1978
Full case name	Parker, Acting Commissioner of Patents and Trademarks v. Flook
Citations	437 U.S. 584 (more) 98 S. Ct. 2522; 57 L. Ed. 2d 451; 1978 U.S. LEXIS 122; 198 U.S.P.Q. (BNA) 193
Prior history	Certiorari to the Court of Customs and Patent Appeals
Subsequent history	Diamond v. Diehr, Diamond v. Chakrabarty
Holding
A mathematical algorithm is not patentable if its application is not novel.
Court membership
Case opinions
Majority	Stevens, joined by Brennan, White, Marshall, Blackmun, Powell
Dissent	Stewart, joined by Burger, Rehnquist
Laws applied
§ 101 of the Patent Act

Parker v. Flook, 437 U.S. 584 (1978), was a 1978 United States Supreme Court decision that ruled that an invention that departs from the prior art only in its use of a mathematical algorithm is patent-eligible only if the implementation is novel and nonobvious. The algorithm itself must be considered as if it were part of the prior art. The case was argued on April 25, 1978 and was decided June 22, 1978. This case is the second member of the Supreme Court's patent-eligibility trilogy.

The case revolves around a patent application for a "Method for Updating Alarm Limits". These limits are numbers between which a catalytic converter is operating normally. The numbers are determined by taking a time-weighted average of values of a relevant operating parameter, such as temperature inside the reactor, in accordance with a smoothing algorithm. When the values of these numbers leave this range an alarm may be sounded. The claims, however, were directed to the numbers (the "alarm limits") themselves.

Flook's method was identical to previous systems except for the mathematical algorithm. In fact, although the patent examiner and the Supreme Court opinions assumed that Flook had originated the mathematical technique, someone else had published it a number of years earlier. In Gottschalk v. Benson, the court had ruled that the discovery of a new formula is not patentable. This case differed from Benson by including a specific application—catalytic conversion of hydrocarbons—for the formula as a claim limitation (a so-called field of use limitation). The patent examiner rejected the patent application as "in practical effect" a claim to the formula or its mathematics. When the decision was appealed, the Board of Appeals of the Patent and Trademark Office sustained the examiner's rejection.

Next, the Court of Customs and Patent Appeals (CCPA) reversed the Board's decision, saying that the patent only claimed the right to the equation in the limited context of the catalytic chemical conversion of hydrocarbons, so that the patent would not wholly pre-empt the use of the algorithm. Finally, the Government, on behalf of the (Acting) Commissioner of Patents and Trademarks, filed a petition for a writ of certiorari to the CCPA in the Supreme Court.