Radio Corp. of America v. Radio Engineering Laboratories, Inc.

Background

The petitioners are assignees of two patents granted to Lee De Forest on September 2, 1924, covering a feed‑back circuit and an audion oscillator. The respondent, Radio Engineering Laboratories, Inc., allied with inventor Armstrong, argued De Forest was not the true first inventor and so the patents were void. The dispute followed many administrative and court fights: Patent Office interferences, decisions for and against claimants, and several suits in federal courts before this final appeal.

Reasoning

The central question was who first invented the feed‑back hookup that produces sustained oscillations and, by extension, the oscillator. The Court stressed that a regularly issued patent carries a strong assumption of correctness, so challengers must present clear, convincing evidence to overturn it. The Court reviewed the same evidence previously considered—De Forest’s notebook entries from August 6, 1912, later experimental notes (including an April 17, 1913 beat note and a February 27, 1914 entry), and testimony about later work—and found that challengers had not met the heavy burden. Because the evidence failed to show error with sufficient clarity, the Court reversed the appeals court and affirmed the district court’s decree for the patent holders.

Real world impact

The decision leaves De Forest’s patents in force and enforceable. That outcome strengthens the position of the patent holders and makes it more difficult for outside parties to defeat such patents on priority grounds without compelling new proof. Companies using or developing similar circuits may face licensing demands or infringement suits.

Dissents or concurrances

The Second Circuit had been divided below, with a dissent arguing De Forest’s title should be upheld; the Chief Justice did not participate in this Court’s consideration.