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U.S. Supreme Court

Detrola Radio & Television Corp. v. Hazeltine Corp., 313 U.S. 259 (1941)

Detrola Radio & Television Corp. v. Hazeltine Corporation

No. 666

Argued April 7, 1941

Decided May 12, 1941

313 U.S. 259


Wheeler reissue patent, No.19,744, Claims 1-7, inclusive, and 9-13, inclusive, relating to amplifiers in modulated current-carrying signaling systems, wherein the limit of amplification is automatically maintained substantially at a predetermined level held invalid for want of invention over the prior art. P. 313 U. S. 268.

The alleged invention, as upheld by the court below, was of improved means for obtaining automatic amplification control by the combination in a radio receiver of a diode detector with a high resistance connected between the anode of the detector and the cathode of the amplifying tube, and a direct connection between the anode of the detector and the grid of the amplifier for impressing negative potential upon the latter, thus obtaining from the signal voltage a so-called linear response to the variations in the amplitude of the signal current.

Page 313 U. S. 260

Wheeler accomplished an old result by a combination of means which, singly or in similar combination, were disclosed by the prior art, and notwithstanding the fact that he was ignorant of the pending applications which antedated his claimed date of invention and eventuated into patents, he was not, in fact, the first inventor, since his advance over the prior art, if any, required only the exercise of the skill of the art.

117 F.2d 238 reversed.

Certiorari, 312 U.S. 671, to review a decree which affirmed the District Court in upholding a patent, enjoining infringement, and retaining jurisdiction to take an account of profits, assess damages, etc.

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