Diamond v. Diehr

Brief Fact Summary. In Diehr’s (Plaintiff) suit against Diamond (Defendant), the patent examiner, for rejection of Plaintiff’s patent on a process for curing synthetic rubber, Defendant argued  that the steps in Plaintiff’s claims that were carried out by a computer under control of a stored program were nonstatutory subject matter under 35 U.S.C. § 101.

Synopsis of Rule of Law. Patentable claims do not become invalid because they include mathematical formulas.

Facts. Plaintiff developed a process for curing synthetic rubber which included the use of a mathematical formula and a programmed digital computer in several of its steps.  Defendant rejected Plaintiff’s claims because steps in Plaintiff’s claims were carried out by a computer controlled by a stored program and therefore were nonstatutory subject matter under 35 U.S.C. § 101.  Defendant concluded that Plaintiff’s claims could not be patented as they defined and sought protection of a computer program for operating a rubber-molding press.  At trial, the Court of Customs and Patent Appeals ruled in Plaintiff’s favor, stating that when the process was considered as a whole, the claim performed a function which the patent laws were designed to protect.  Defendant appealed.

Issue. Do patentable claims become invalid because they include mathematical formulas?

Held. (Rehnquist, J.)  No.  Patentable claims do not become invalid because they include mathematical formulas.  It is now commonplace that an application of a law of nature or mathematical formula to a known structure or process may deserve patent protection.  In deciding whether Plaintiff’s claim process is eligible for patent protection under § 101, the claims must be considered as a whole.  Plaintiff’s claims are nothing more than a process for molding rubber products, not an attempt to patent a mathematical formula.  Plaintiff’s claims, which contain a mathematical formula, transform an article to a different state, which is performing a function which the patent laws were designed to protect.  Affirmed.

Discussion. In deciding the eligibility of a claimed process for patent protection under § 101, their claims must be considered as a whole.  In is not appropriate to separate claims into old and new elements and ignore the presence of the old elements in the analysis.  This is especially true in a process claim because a new combination of steps in a process may be patentable even though all the parts of the combination were well known and in common use before the combination was made.