EB: DIAMOND v. DIEHR, 450 U.S. 175 (1981)

The Situation

Diehr files a patent for a process of constantly measuring the temperature inside a mold for curing synthetic rubber, and transfers the temperature measurements into a computer that "repeatedly recalculates" the cure time using a mathematical equation which then signals a device to open the mold at the proper time.
Patent originally rejected, examiner cites prior case (Gottchalk) in regards to the unpatentable nature of computer programs
The decision was appealed, one Appeal agreed to reject the patent, the next reversed the opinion - Supreme Court steps in to make a decision

Diehr's patent is valid; the subject matter is patentable.
- However, it was a very slit decision (5 to 4)

The subject matter, when taken as a whole, constitutes the "transform and reduce into a different state or thing" criteria of a "process" - the subject matter clearly transforms raw rubber into cured precision products.
The patentee's do not seek to "pre-empt" the formula (Arrhenius equation), but only to get rights to its use in conjunction with all of the other steps in the claimed process.
- The decision regarding the claims cannot be "altered by the fact that in several steps of the process a mathemetical equation and a programmed digital computer are used"
While a scientific truth (the Arrhenius equation) cannot be patented, "a neovel and usefulstructure created with the aid of knowledge of scientific truth may be"

The others misinterpret the claims of the patent
The others confuse patentable subject matter with novelty - see last bullet point of previous section
- Diehr does not claim to have discovered anything new about the process for curing synthetic rubber
- The curing process is previously known, as is the general method of continuously measuring temperature
The invention makes no contribution to the art that is not "entirely dependent upon the utilization of a computer in a familiar process" - thus, it should not be patentable