Паркер против Флука: Математикалық алгоритмдерді патенттеу шектеулері

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 there is some other "inventive concept in its application." The algorithm itself must be considered as if it were part of the prior art, and the claim must be considered as a whole. 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 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.

The law which is applicable to this case is section 101 of the Patent Act. If Flook's patent claim can meet the definition of a "process" under that law then it is patent eligible (that is, it is the kind of thing that can receive a patent if it is also novel, unobvious, and the like). The Court decided that the patent claim under review was instead a claim to a "principle" or a "law of nature" and thus not patent eligible. The Court relied on a line of cases following from the Neilson blast furnace case. The principle of that case, as explained in O'Reilly v. Morse, is that that patent eligibility must be analyzed on the basis of it being as if the principle, algorithm, or mathematical formula were already well known (was in the prior art). Flook's process is thus ineligible for a patent "because, once that algorithm is assumed to be within the prior art, the application, considered as a whole, contains no patentable invention." In a nutshell:
Even though a phenomenon of nature or mathematical formula may be well known, an inventive application of the principle may be patented. Conversely, the discovery of such a phenomenon cannot support a patent unless there is some other inventive concept in its application. [Emphasis supplied.] The Court did not agree with Flook's assertion that the existence of a limitation to a specific field of use made the formula patent eligible. The majority opinion said of this argument:
A competent draftsman could attach some form of post solution activity to almost any mathematical formula; the Pythagorean theorem would not have been patentable, or partially patentable, because a patent application contained a final step indicating that the formula, when solved, could be usefully applied to existing surveying techniques. The court moderated that assertion by agreeing that not all patent applications involving formulas are patent ineligible by saying, "Yet it is equally clear that a process is not unpatentable simply because it contains a law of nature or a mathematical algorithm." Patents involving formulas, laws of nature, or abstract principles are eligible for patent protection if the implementation of the principle is novel and unobvious—unlike this case, in which it was conceded that the implementation was conventional. Accordingly, in Flook's case, there was no "other inventive concept in its application", and thus no eligibility for a patent.