Diamond v. Diehr

LOCATION: U.S. Department of State

DOCKET NO.: 79-1112
DECIDED BY: Burger Court (1975-1981)

CITATION: 450 US 175 (1981)
ARGUED: Oct 14, 1980
DECIDED: Mar 03, 1981

Lawrence G. Wallace - for petitioner
Robert E. Wickersham - Argued the cause for the petitioner
Robert E. Wichersham - on behalf of the Respondents

Facts of the case

Engineers James Diehr and Theodore Lutton invented an improved press that cured rubber by controlled heating. The press contained a temperature probe which measured the temperature rise of the rubber from within the press. By repeatedly calculating the rubber cure time from this temperature measurement and comparing this computed cure time to the actual elapsed time, the computer was able to determine precisely when to open the press and eject the cured rubber, which then emerged perfectly cured. The patent examiner, viewing all computer programs as unpatentable because of the earlier Supreme Court decision Gottschalk v. Benson (1972), rejected their patent application because, he argued, the inventors had simply combined an unpatentable program with a conventional rubber curing press. An appellate court reversed the Examiner and ordered a patent to issue. The Commissioner of Patents then petitioned successfully to have the Supreme Court review this decision. Before the Supreme Court, the inventors' attorney argued that the steps of continuously measuring temperature and repeatedly recalculating the rubber cure time and comparing it to the elapsed time were new steps that were worthy of patent protection.


Can one patent a machine that transforms materials physically under the control of a programmed computer?

Media for Diamond v. Diehr

Audio Transcription for Oral Argument - October 14, 1980 in Diamond v. Diehr

Audio Transcription for Opinion Announcement - March 03, 1981 in Diamond v. Diehr

Warren E. Burger:

The judgment and opinion of the Court in Diamond, the Commissioner of Patents and Trademarks against Diehr will be announced by Mr. Justice Rehnquist.

William H. Rehnquist:

This case comes to us from the United States Court of Customs and Patent Appeals and presents the question of whether a process for curing synthetic rubber which includes in several of its steps the use of a mathematical formula and a programmed digital computer is subject matter eligible for patent protection under 35 U.S.C. Section 101.

That section provides for the issuance of patents to whoever invents or discovers any new or useful process, machines, manufacture or composition of matter or any new and useful improvement thereof.

The respondents claim to have invented a process that will ensure the creation of a perfectly cured rubber product.

Previously, the industry have been unable to obtain a perfect cure because it could not precisely measure the temperature inside the molding press, thus making it difficult to make the necessary computations to determine how long the cure should take.

Respondents characterized their contribution to the art as inhering in the process of constantly measuring and finding the temperature inside the mold and feeding these temperature measurements into a computer which calculates the proper cure time and then signals the device to open the press at the completion of the cure.

A process is eligible for patent protection if it transforms or reduces an article to a different state or thing.

Processes for curing rubber have historically been eligible for patent protection and it cannot be doubted that respondents' claim involves the transformation of an article in this case uncured synthetic rubber into a different state.

We hope the respondents' process for patent protection does not lose its eligibility under Section 101 because it uses as a mathematical formula and a program digital computer and several of its steps.

While a mathematical formula, like a law of nature, cannot be the subject of a patent.

Respondents do not seek to patent a mathematical formula, instead they seek protection for a complete process for curing synthetic rubber beginning with the loading of a mold with uncured rubber and ending with the opening of the press at the completion of the cure.

A claim drawn to subject matter otherwise statutory does not become nonstatutory simply because it uses a mathematical formula, computer program or digital computer.

Respondents' claims must be considered as a whole because we do not view their claims as an attempt to patent a mathematical formula, but rather to be drawn to an industrial process for the molding of rubber products.

We affirm the judgment of the Court of Customs and Patent Appeals.

Justice Stevens has filed a dissenting opinion with which Justice Brennan, Justice Marshall and Justice Blackmun joined.

Warren E. Burger:

Thank you, Mr. Justice Rehnquist.