Lee de Forest - Patents

Patents

Patent images in TIFF format

• U.S. Patent 748,597 "Wireless Signaling Device" (directional antenna), filed December 1902, issued January 1904;
• U.S. Patent 824,637 "Oscillation Responsive Device" (vacuum tube detector diode), filed January 1906, issued June 1906;
• U.S. Patent 827,523 "Wireless Telegraph System" (separate transmitting and receiving antennas), filed December 1905, issued July 1906;
• U.S. Patent 827,524 "Wireless Telegraph System", filed January 1906 issued July 1906;
• U.S. Patent 836,070 "Oscillation Responsive Device" (vacuum tube detector – no grid), filed May 1906, issued November 1906;
• U.S. Patent 841,386 "Wireless Telegraphy" (tunable vacuum tube detector – no grid), filed August 1906, issued January 1907;
• U.S. Patent 841,387 "Device for Amplifying Feeble Electrical Currents" (...), filed August 1906, issued January 1907;
• U.S. Patent 876,165 "Wireless Telegraph Transmitting System" (antenna coupler), filed May 1904, issued January 1908;
• U.S. Patent 879,532 "Space Telegraphy" (increased sensitivity detector – clearly shows grid), filed January 1907, issued February 18, 1908;
• U.S. Patent 926,933 "Wireless Telegraphy";
• U.S. Patent 926,934 "Wireless Telegraph Tuning Device";
• U.S. Patent 926,935 "Wireless Telegraph Transmitter", filed February 1906, issued July 1909;
• U.S. Patent 926,936 "Space Telegraphy";
• U.S. Patent 926,937 "Space Telephony";
• U.S. Patent 979,275 "Oscillation Responsive Device" (parallel plates in Bunsen flame) filed February 1905, issued December 1910;
• U.S. Patent 1,025,908 "Transmission of Music by Electromagnetic Waves";
• U.S. Patent 1,101,533 "Wireless Telegraphy" (directional antenna/direction finder), filed June 1906, issued June 1914;
• U.S. Patent 1,214,283 "Wireless Telegraphy".