Software Patents in the United States

Throughout the 1950s, 1960s and 1970s, the United States Patent Office refused to grant patents to inventions which used a calculation made by a computer. The Patent Office's rationale was that patents should not be granted to mathematical algorithms. The Supreme Court upheld this view in Gottschalk v. Benson (1972) and Parker v. Flook (1975).

However, the Supreme Court reversed course in Diamond v. Diehr (1981) when the Court ordered the Patent Office to grant a patent on an invention which substantially consisted of a computer program that calculated the time necessary for rubber to be cured. The Court reasoned that the invention was not an algorithm, but rather a process for curing and molding rubber.

Subsequent decisions by the Federal Circuit affirmed that a numerical calculation that produces a "useful, concrete and tangible result" is patentable. In 1995, the PTO made it easier to obtain software patents by establishing broad guidelines for examining and issuing software patents. Up to this point, Congress has not legislated on the patentability of software patents. However, the failure of Congress to change the law in response to the Federal Circuit allowing software patents has been interpreted as Congress' intent for courts to keep the current form of software patentability. In addition, the Supreme Court remains silent on recent software patent developments.