Citation[]
Diamond v. Diehr, 450 U.S. 175, 209 U.S.P.Q. (BNA) 1 (1981) (full-text).
Factual Background[]
The application in Diehr recited a process of curing synthetic rubber. The process included use of a known mathematical formula to determine the time for curing, and a programmed digital computer to determine the proper length of time for curing the product and automatically opening the mold. The claims were rejected by the Patent Office as non-statutory subject matter. The Court of Customs and Patent Appeals reversed.
U.S. Supreme Court Proceedings[]
The U.S. Supreme Court decided in a 5 to 4 decision that the process was patentable under 35 U.S.C. §101. The claims were not disqualified from patentability because of the use of a mathematical equation and programmed digital computer.
The Supreme Court characterized a mathematical formula or an algorithm to be "like a law of nature, which cannot be the subject of a patent." The Court asserted that a claim drawn to otherwise statutory subject matter is not rendered nonstatutory simply because it involves a mathematical formula, computer program, or digital computer. The Court stated that the claims must be considered in their entirety, and held that the incorporation of a computer in the process claimed in the application does not render the process as a whole to be unpatentable subject matter.
The Court in Diehr clearly stated that purely mathematical procedures or algorithms alone are not proper subject matter of patent protection:
| “ | [W]hen a claim recites a mathematical formula (or scientific principle or phenomenon of nature), an inquiry must be made into whether the claim is seeking patent protection for that formula in the abstract. A mathematical formula as such is not accorded the protection of our patent laws, and this principle cannot be circumvented by attempting to limit the use of the formula to a particular technological environment. Similarly, insignificant post-solution activity will not transform an unpatentable principle into a patentable process. To hold otherwise would allow a competent draftsman to evade the recognized limitations on the type of subject matter eligible for patent protection. | ” |
In cases such as that being considered by the Court, however, where the applicant wishes to protect an overall industrial process rather than simply a mathematical formula, the circumstances change.
| “ | [W]hen a claim containing a mathematical formula implements or applies that formula in a structure or process which, when considered as a whole, is performing a function which the patent laws were designed to protect (e.g., transforming or reducing an article to a different state or thing), then the claim satisfies the requirements of Section 101. | ” |
This was the third of the patentable subject matter "trilogy", which also included Gottschalk v. Benson and Parker v. Flook.
Comment[]
Diehr indicates that at least some subject matter involving software may be patented and that algorithms may be included as part of patentable subject matter.