Telefunken AG
TelefunkenActive Patents
0
Total Holdings
353
Patent Holdings
Filter in Explorer →| Patent No. | Title | Status | Filing Date | Grant Date | Claims | Actions |
|---|---|---|---|---|---|---|
| GB891754A | Improvements in or relating to radio systems for supplying … | Expired / Lapsed | 1961-01-05 | — | 0 | Details |
| DE1100874B | Arrangement for performing stomach and intestinal examinati… | Expired / Lapsed | 1960-01-16 | — | 0 | Details |
| DE1051335B | Module carrier for modules for electrical communications an… | Expired / Lapsed | 1958-04-25 | — | 0 | Details |
| DE1054505B | Transistor circuit for generating approximately square-wave… | Expired / Lapsed | 1957-02-23 | — | 0 | Details |
| DE1014167B | Wing chair with built-in speakers | Expired / Lapsed | 1955-08-03 | — | 0 | Details |
| GB503471A | Improvements in or relating to navigation aiding radio rece… | Expired / Lapsed | 1938-10-10 | — | 0 | Details |
| GB501121A | Improvements in piezo-electric crystals | Expired / Lapsed | 1938-09-07 | — | 0 | Details |
| GB480572A | Improvements in or relating to direction finding radio rece… | Expired / Lapsed | 1937-06-17 | — | 0 | Details |
| GB460488A | Improvements in or relating to directional radio receivers | Expired / Lapsed | 1936-05-23 | — | 0 | Details |
| GB449392A | Improvements in or relating to fluorescent or luminescent s… | Expired / Lapsed | 1934-12-19 | — | 0 | Details |
| GB397081A | Improvements in or relating to electric cables for use for … | Expired / Lapsed | 1933-05-10 | — | 0 | Details |
| GB379957A | Improvements in or relating to thermionic valve circuits | Expired / Lapsed | 1932-01-11 | — | 0 | Details |
| GB367278A | Improvements in or relating to aerial arrangements for use … | Expired / Lapsed | 1931-06-22 | — | 0 | Details |
| GB347865A | Improvements in or relating to short wave radio receivers | Expired / Lapsed | 1930-04-16 | — | 0 | Details |
| GB317826A | Improvements in or relating to radio direction finding | Expired / Lapsed | 1929-08-16 | — | 0 | Details |
| GB172321A | Improved calling apparatus for high frequency telegraphy | Expired / Lapsed | 1921-12-02 | — | 0 | Details |
| US3247404A | Electro-mechanical transducer | Expired / Lapsed | 1958-02-13 | 1966-04-19 | 0 | Details |
| US3214519A | Reproducing system | Expired / Lapsed | 1961-12-14 | 1965-10-26 | 2 | Details |
| US3204198A | Circuit arrangement for changing the oscillator frequency o… | Expired / Lapsed | 1960-12-05 | 1965-08-31 | 2 | Details |
| US3181150A | Indicating device | Expired / Lapsed | 1960-11-25 | 1965-04-27 | 2 | Details |
| US3144017A | Pill-type swallowable transmitter | Expired / Lapsed | 1961-01-03 | 1964-08-11 | 2 | Details |
| US3116174A | Method of producing low-capacitance barrier layers in semi-… | Expired / Lapsed | 1959-12-29 | 1963-12-31 | 2 | Details |
| US3098219A | Monitoring aprangement for programcontrolled electronic com… | Expired / Lapsed | 1958-01-27 | 1963-07-16 | 0 | Details |
| US3068473A | System for supervision of vehicles | Expired / Lapsed | 1959-11-03 | 1962-12-11 | 0 | Details |
| US3040132A | Transmission system | Expired / Lapsed | 1960-03-11 | 1962-06-19 | 0 | Details |
| US3038028A | Arrangement for producing a series of pulses | Expired / Lapsed | 1958-02-07 | 1962-06-05 | 0 | Details |
| US3032720A | Oscillator synchronizing circuits with plural phase compari… | Expired / Lapsed | 1958-09-29 | 1962-05-01 | 0 | Details |
| US2998335A | Method and apparatusfor growing single crystals from molten… | Expired / Lapsed | 1957-01-31 | 1961-08-29 | 2 | Details |
| US2994047A | Mechanical filter coupling | Expired / Lapsed | 1958-12-03 | 1961-07-25 | 0 | Details |
| US2992144A | Method of forming transistors | Expired / Lapsed | 1959-05-29 | 1961-07-11 | 2 | Details |
| US2963700A | Scanning system and method | Expired / Lapsed | 1956-02-08 | 1960-12-06 | 0 | Details |
| US2962666A | Oscillator synchronizing circuit with variable pull in range | Expired / Lapsed | 1959-10-06 | 1960-11-29 | 0 | Details |
| US2961485A | Remote indicator system | Expired / Lapsed | 1956-06-18 | 1960-11-22 | 0 | Details |
| US2895111A | Frequency response curve equalization | Expired / Lapsed | 1957-10-17 | 1959-07-14 | 0 | Details |
| US2867765A | Tuner and range switch | Expired / Lapsed | 1956-01-24 | 1959-01-06 | 0 | Details |
| DE970248C | Arrangement for the use of a telemeter in the form of a mag… | Expired / Lapsed | 1952-11-27 | 1958-08-28 | 0 | Details |
| US2845491A | Stereophonic apparatus | Expired / Lapsed | 1956-12-17 | 1958-07-29 | 0 | Details |
| DE927999C | Apparatus for magnetic recording and reproduction of televi… | Expired / Lapsed | 1953-07-01 | 1955-05-23 | 0 | Details |
| DE864696C | Condenser microphone | Expired / Lapsed | 1942-04-01 | 1953-01-26 | 0 | Details |
| DE801041C | Process for welding objects made of dielectric materials | Expired / Lapsed | 1948-10-02 | 1950-12-21 | 0 | Details |
| FR898352A | Improvements to simultaneous or alternative production syst… | Expired / Lapsed | 1943-09-29 | 1945-04-20 | 0 | Details |
| FR892851A | Improvements to reverse-feedback push-pull amplifiers with … | Expired / Lapsed | 1943-03-25 | 1944-05-23 | 0 | Details |
| FR890924A | Hollow tubular pipe for very short electrical waves | Expired / Lapsed | 1943-02-10 | 1944-02-22 | 0 | Details |
| DE738336C | Device for determining distance | Expired / Lapsed | 1937-10-01 | 1943-08-11 | 0 | Details |
| DE734905C | Circuit arrangement for the generation of saw-tooth-shaped … | Expired / Lapsed | 1936-03-13 | 1943-04-30 | 0 | Details |
| FR877692A | Improvements to hollow lines for UHF | Expired / Lapsed | 1941-12-12 | 1942-12-14 | 0 | Details |
| US2292914A | Luminescent material | Expired / Lapsed | 1940-03-20 | 1942-08-11 | 0 | Details |
| US2292722A | Telemetric indicator of corrected angular positions | Expired / Lapsed | 1939-09-05 | 1942-08-11 | 0 | Details |
| US2292161A | Magnetic shielding | Expired / Lapsed | 1940-03-02 | 1942-08-04 | 0 | Details |
| FR873812A | Improvements to image sensor tubes, in particular for telev… | Expired / Lapsed | 1941-07-12 | 1942-07-21 | 0 | Details |
| US2289840A | Frequency modulation receiver | Expired / Lapsed | 1940-06-26 | 1942-07-14 | 0 | Details |
| US2285857A | Receiver | Expired / Lapsed | 1937-11-11 | 1942-06-09 | 0 | Details |
| US2285164A | Radio frequency amplifier | Expired / Lapsed | 1940-08-24 | 1942-06-02 | 0 | Details |
| US2282856A | Magnetron oscillator | Expired / Lapsed | 1941-04-17 | 1942-05-12 | 0 | Details |
| DE720448C | Push-pull shortwave tubes with two discharge systems within… | Expired / Lapsed | 1937-08-26 | 1942-05-06 | 0 | Details |
| US2281982A | Arrangement for transmitting and receiving wireless messages | Expired / Lapsed | 1940-10-05 | 1942-05-05 | 0 | Details |
| US2281069A | Modulation system | Expired / Lapsed | 1935-02-27 | 1942-04-28 | 0 | Details |
| US2278601A | Antenna tunable in its length | Expired / Lapsed | 1939-12-09 | 1942-04-07 | 0 | Details |
| US2276617A | Tuning arrangement | Expired / Lapsed | 1939-11-10 | 1942-03-17 | 0 | Details |
| US2273511A | Means to transform an alternating potential | Expired / Lapsed | 1938-11-02 | 1942-02-17 | 0 | Details |
| US2271550A | Optical and acoustic indicator for directional receivers | Expired / Lapsed | 1939-01-12 | 1942-02-03 | 0 | Details |
| US2270949A | Conductor arrangement for use with radio frequency apparatus | Expired / Lapsed | 1941-02-28 | 1942-01-27 | 0 | Details |
| US2270922A | Piezoelectric crystal holder | Expired / Lapsed | 1939-10-17 | 1942-01-27 | 0 | Details |
| US2270771A | High frequency oscillation generator | Expired / Lapsed | 1940-10-31 | 1942-01-20 | 0 | Details |
| US2270773A | Impulse direction finder | Expired / Lapsed | 1938-03-08 | 1942-01-20 | 0 | Details |
| US2269249A | Controlled feedback circuit | Expired / Lapsed | 1938-11-29 | 1942-01-06 | 0 | Details |
| US2267951A | Antenna | Expired / Lapsed | 1940-01-24 | 1941-12-30 | 0 | Details |
| US2266868A | Antenna system | Expired / Lapsed | 1940-06-29 | 1941-12-23 | 0 | Details |
| US2266920A | Television transmitting tube | Expired / Lapsed | 1939-01-09 | 1941-12-23 | 0 | Details |
| US2266525A | Wave range switching mechanism | Expired / Lapsed | 1940-06-20 | 1941-12-16 | 0 | Details |
| US2266532A | Slide contact or wiper for cylindrical coils | Expired / Lapsed | 1938-12-15 | 1941-12-16 | 0 | Details |
| US2265784A | Method of producing electrical oscillations | Expired / Lapsed | 1939-08-31 | 1941-12-09 | 0 | Details |
| US2265833A | Ultra short wave oscillatory circuit | Expired / Lapsed | 1939-06-30 | 1941-12-09 | 0 | Details |
| US2265825A | Impulse segregation circuits | Expired / Lapsed | 1938-09-10 | 1941-12-09 | 0 | Details |
| US2264724A | Receiver for frequency or phase modulated oscillations | Expired / Lapsed | 1939-12-14 | 1941-12-02 | 0 | Details |
| US2258836A | Cathode heater | Expired / Lapsed | 1940-06-19 | 1941-10-14 | 0 | Details |
| US2258148A | Transmission line | Expired / Lapsed | 1938-10-04 | 1941-10-07 | 0 | Details |
| US2256090A | Method and means for guiding aircraft | Expired / Lapsed | 1937-12-24 | 1941-09-16 | 0 | Details |
| US2254344A | Sawtooth wave generator | Expired / Lapsed | 1937-02-10 | 1941-09-02 | 0 | Details |
| US2252447A | Impulse direction-finding method | Expired / Lapsed | 1938-02-11 | 1941-08-12 | 0 | Details |
| US2250581A | Receiver volume control | Expired / Lapsed | 1939-09-26 | 1941-07-29 | 0 | Details |
| US2250706A | Saw-tooth wave generator | Expired / Lapsed | 1938-09-29 | 1941-07-29 | 0 | Details |
| US2250686A | Saw-tooth wave oscillator | Expired / Lapsed | 1938-09-17 | 1941-07-29 | 0 | Details |
| US2250559A | Amplifier gain control circuit | Expired / Lapsed | 1938-07-28 | 1941-07-29 | 0 | Details |
| US2250526A | Oscillator control circuit | Expired / Lapsed | 1938-01-28 | 1941-07-29 | 0 | Details |
| US2250708A | Time interval measuring means | Expired / Lapsed | 1938-01-13 | 1941-07-29 | 0 | Details |
| US2250090A | Arrangement for tuning high frequency oscillation circuits | Expired / Lapsed | 1939-10-05 | 1941-07-22 | 0 | Details |
| US2249933A | Piezoelectric plate | Expired / Lapsed | 1939-09-26 | 1941-07-22 | 0 | Details |
| US2249420A | Frequency meter | Expired / Lapsed | 1938-08-31 | 1941-07-15 | 0 | Details |
| US2245669A | Oscillation generator | Expired / Lapsed | 1938-12-17 | 1941-06-17 | 0 | Details |
| US2245178A | Piezoelectric crystal | Expired / Lapsed | 1939-03-02 | 1941-06-10 | 0 | Details |
| US2244023A | Wave-band switching system | Expired / Lapsed | 1939-02-01 | 1941-06-03 | 0 | Details |
| US2243234A | Wave indication | Expired / Lapsed | 1940-01-18 | 1941-05-27 | 0 | Details |
| US2243202A | Circuit for automatic frequency control | Expired / Lapsed | 1938-09-14 | 1941-05-27 | 0 | Details |
| US2239865A | Cathode ray deflecting coil | Expired / Lapsed | 1939-02-01 | 1941-04-29 | 0 | Details |
| US2239906A | Noise control circuit | Expired / Lapsed | 1938-12-13 | 1941-04-29 | 0 | Details |
| US2238129A | Directional radio receiver | Expired / Lapsed | 1937-06-25 | 1941-04-15 | 0 | Details |
| US2237792A | Antenna system and feeder | Expired / Lapsed | 1939-04-29 | 1941-04-08 | 0 | Details |
| US2237425A | Saw-tooth wave generator | Expired / Lapsed | 1938-06-15 | 1941-04-08 | 0 | Details |
| US2237448A | Overload protection for dynamic loud-speakers | Expired / Lapsed | 1938-06-07 | 1941-04-08 | 0 | Details |
| US2237895A | Impulse direction-finding receiver | Expired / Lapsed | 1938-05-28 | 1941-04-08 | 0 | Details |
| US2236015A | Homing impulse direction finder | Expired / Lapsed | 1938-09-10 | 1941-03-25 | 0 | Details |
| US2235053A | Cathode ray control apparatus | Expired / Lapsed | 1937-07-24 | 1941-03-18 | 0 | Details |
| US2234654A | Direction finder | Expired / Lapsed | 1935-02-15 | 1941-03-11 | 0 | Details |
| US2233779A | Electron discharge device | Expired / Lapsed | 1936-11-27 | 1941-03-04 | 0 | Details |
| US2232833A | Band width control | Expired / Lapsed | 1939-11-14 | 1941-02-25 | 0 | Details |
| US2230546A | Circuit for the amplification of ultra-high frequencies | Expired / Lapsed | 1939-02-16 | 1941-02-04 | 0 | Details |
| US2227076A | Circuit arrangement for electrostatic deflection of cathode… | Expired / Lapsed | 1939-02-24 | 1940-12-31 | 0 | Details |
| US2227075A | Saw-tooth current generator | Expired / Lapsed | 1939-01-19 | 1940-12-31 | 0 | Details |
| US2227078A | Heterodyne receiver for ultrashort waves | Expired / Lapsed | 1938-10-15 | 1940-12-31 | 0 | Details |
| US2226694A | Neutralization circuit for short wave transmitters | Expired / Lapsed | 1938-02-02 | 1940-12-31 | 0 | Details |
| US2227108A | Signaling system | Expired / Lapsed | 1937-02-19 | 1940-12-31 | 0 | Details |
| US2223995A | Impulse reception | Expired / Lapsed | 1938-04-20 | 1940-12-03 | 0 | Details |
| US2222668A | Infrared ray generator and communication system | Expired / Lapsed | 1938-07-15 | 1940-11-26 | 0 | Details |
| US2222770A | Inductance coil and condenser assembly | Expired / Lapsed | 1938-07-13 | 1940-11-26 | 0 | Details |
| US2222784A | Protection circuit | Expired / Lapsed | 1938-03-02 | 1940-11-26 | 0 | Details |
| US2222169A | Short wave tuning | Expired / Lapsed | 1938-03-16 | 1940-11-19 | 0 | Details |
| US2220964A | Television transmitter tube | Expired / Lapsed | 1938-01-21 | 1940-11-12 | 0 | Details |
| US2220712A | Saw-tooth wave generator | Expired / Lapsed | 1938-08-30 | 1940-11-05 | 0 | Details |
| US2220688A | Arrangement for receiving television images | Expired / Lapsed | 1937-05-27 | 1940-11-05 | 0 | Details |
| US2219506A | Tuning indicator circuit | Expired / Lapsed | 1937-10-08 | 1940-10-29 | 0 | Details |
| US2219449A | Modulation | Expired / Lapsed | 1937-05-01 | 1940-10-29 | 0 | Details |
| US2219653A | Transmission line | Expired / Lapsed | 1936-12-16 | 1940-10-29 | 0 | Details |
| US2219003A | Trimming condenser | Expired / Lapsed | 1939-01-17 | 1940-10-22 | 0 | Details |
| US2218636A | Radio transmitter synchronization | Expired / Lapsed | 1938-07-29 | 1940-10-22 | 0 | Details |
| US2217321A | Beam antenna | Expired / Lapsed | 1936-05-22 | 1940-10-08 | 0 | Details |
| US2215946A | Circuit for reducing electrical disturbances | Expired / Lapsed | 1938-12-27 | 1940-09-24 | 0 | Details |
| US2213550A | Periodic direct current interrupter | Expired / Lapsed | 1938-11-18 | 1940-09-03 | 0 | Details |
| US2212128A | Antenna | Expired / Lapsed | 1939-05-06 | 1940-08-20 | 0 | Details |
| US2212110A | Radio beacon system | Expired / Lapsed | 1937-08-04 | 1940-08-20 | 0 | Details |
| US2212249A | Electronic device | Expired / Lapsed | 1936-09-10 | 1940-08-20 | 0 | Details |
| US2210987A | Cathode ray tube | Expired / Lapsed | 1936-08-05 | 1940-08-13 | 0 | Details |
| US2210045A | Piezo-electric crystal holder | Expired / Lapsed | 1938-10-20 | 1940-08-06 | 0 | Details |
| US2208349A | Direction finder | Expired / Lapsed | 1938-02-11 | 1940-07-16 | 0 | Details |
| US2206668A | Electronic device | Expired / Lapsed | 1937-05-26 | 1940-07-02 | 0 | Details |
| US2205874A | Arrangement for matching a high frequency radiator to a tra… | Expired / Lapsed | 1937-12-24 | 1940-06-25 | 0 | Details |
| US2205582A | Method of sealing glass | Expired / Lapsed | 1937-12-18 | 1940-06-25 | 0 | Details |
| US2205881A | Antenna supervisory system | Expired / Lapsed | 1937-12-04 | 1940-06-25 | 0 | Details |
| US2205866A | Capacitive radio frequency voltage divider | Expired / Lapsed | 1937-11-26 | 1940-06-25 | 0 | Details |
| US2205873A | Method of measuring power on highfrequency energy lines | Expired / Lapsed | 1937-04-30 | 1940-06-25 | 0 | Details |
| US2204962A | Automatic volume control | Expired / Lapsed | 1938-09-29 | 1940-06-18 | 0 | Details |
| US2205075A | Variable width band-pass filter | Expired / Lapsed | 1937-07-10 | 1940-06-18 | 0 | Details |
| US2202380A | Confined or space resonance antenna | Expired / Lapsed | 1937-11-11 | 1940-05-28 | 0 | Details |
| US2202605A | Television system | Expired / Lapsed | 1937-08-07 | 1940-05-28 | 0 | Details |
| US2202511A | Black spot compensation apparatus | Expired / Lapsed | 1937-04-28 | 1940-05-28 | 0 | Details |
| US2202527A | Cathode ray switch | Expired / Lapsed | 1936-09-10 | 1940-05-28 | 0 | Details |
| US2201666A | Magnetron | Expired / Lapsed | 1938-03-04 | 1940-05-21 | 0 | Details |
| US2195455A | Electronic system | Expired / Lapsed | 1937-02-24 | 1940-04-02 | 0 | Details |
| US2195103A | Television system | Expired / Lapsed | 1936-03-26 | 1940-03-26 | 0 | Details |
| US2194175A | Distortion reducing arrangement | Expired / Lapsed | 1938-08-04 | 1940-03-19 | 0 | Details |
| US2193868A | Circuit arrangement for producing an impulse series | Expired / Lapsed | 1937-06-17 | 1940-03-19 | 0 | Details |
| US2192975A | Method of sending and receiving radio frequency impulses | Expired / Lapsed | 1938-01-27 | 1940-03-12 | 0 | Details |
| US2193101A | Electrode structure | Expired / Lapsed | 1937-04-27 | 1940-03-12 | 0 | Details |
| US2189284A | Adjustable two-pole capacitive coupler | Expired / Lapsed | 1937-11-26 | 1940-02-06 | 0 | Details |
| US2189584A | Transmitter | Expired / Lapsed | 1937-06-18 | 1940-02-06 | 0 | Details |
| US2189351A | Television transmission | Expired / Lapsed | 1934-06-14 | 1940-02-06 | 0 | Details |
| US2187575A | Antenna winch for aircraft | Expired / Lapsed | 1938-06-25 | 1940-01-16 | 0 | Details |
| US2187584A | High frequency energy line | Expired / Lapsed | 1937-04-21 | 1940-01-16 | 0 | Details |
| US2187618A | Radio beacon system | Expired / Lapsed | 1936-06-06 | 1940-01-16 | 0 | Details |
| US2183260A | Phase displacement detector | Expired / Lapsed | 1937-04-16 | 1939-12-12 | 0 | Details |
| US2182555A | Saw-tooth wave generator | Expired / Lapsed | 1937-07-24 | 1939-12-05 | 0 | Details |
| US2182608A | Saw-tooth wave generator | Expired / Lapsed | 1937-03-17 | 1939-12-05 | 0 | Details |
| US2181568A | Impulse or pulse transmitter | Expired / Lapsed | 1937-01-13 | 1939-11-28 | 0 | Details |
| US2181309A | Electrical impulse segregation circuit | Expired / Lapsed | 1936-05-21 | 1939-11-28 | 0 | Details |
| US2180710A | Cathode ray tube screen | Expired / Lapsed | 1937-04-19 | 1939-11-21 | 0 | Details |
| US2178340A | Wave form modifying circuits | Expired / Lapsed | 1937-03-29 | 1939-10-31 | 0 | Details |
| US2178074A | Electrical measuring system | Expired / Lapsed | 1936-10-09 | 1939-10-31 | 0 | Details |
| FR848207A | Improvements to antifading fixtures in television receivers | Expired / Lapsed | 1938-12-30 | 1939-10-25 | 0 | Details |
| US2175320A | Remote control device for radio receivers | Expired / Lapsed | 1938-07-09 | 1939-10-10 | 0 | Details |
| US2175335A | Television synchronizing circuits | Expired / Lapsed | 1937-05-06 | 1939-10-10 | 0 | Details |
| US2175573A | Electron beam converter | Expired / Lapsed | 1936-03-20 | 1939-10-10 | 0 | Details |
| US2173643A | Radio frequency cable terminal | Expired / Lapsed | 1936-01-21 | 1939-09-19 | 0 | Details |
| US2172775A | Optical system | Expired / Lapsed | 1936-01-28 | 1939-09-12 | 0 | Details |
| US2171638A | Automatic volume control | Expired / Lapsed | 1936-02-04 | 1939-09-05 | 0 | Details |
| US2171212A | Electron discharge device | Expired / Lapsed | 1937-03-27 | 1939-08-29 | 0 | Details |
| US2170219A | Ultra high frequency oscillator | Expired / Lapsed | 1937-10-28 | 1939-08-22 | 0 | Details |
| US2169883A | Television and sound receiver | Expired / Lapsed | 1937-11-02 | 1939-08-15 | 0 | Details |
| US2169358A | Receiver for ultra-short waves | Expired / Lapsed | 1937-06-18 | 1939-08-15 | 0 | Details |
| US2169714A | Black spot correcting means | Expired / Lapsed | 1937-05-13 | 1939-08-15 | 0 | Details |
| US2167462A | Variable electric filter | Expired / Lapsed | 1937-03-04 | 1939-07-25 | 0 | Details |
| US2166124A | Method of detecting high-frequency oscillations | Expired / Lapsed | 1937-11-03 | 1939-07-18 | 0 | Details |
| DE678290C | Arrangement for touching two antenna structures in the rhyt… | Expired / Lapsed | 1935-08-28 | 1939-07-12 | 0 | Details |
| US2165848A | Protection of high frequency lines | Expired / Lapsed | 1937-04-21 | 1939-07-11 | 0 | Details |
| US2164891A | Electromagnetic cathode ray deflection apparatus | Expired / Lapsed | 1936-08-11 | 1939-07-04 | 0 | Details |
| US2163707A | Wide band modulation | Expired / Lapsed | 1937-02-27 | 1939-06-27 | 0 | Details |
| US2163266A | Double mosaic screen | Expired / Lapsed | 1937-01-09 | 1939-06-20 | 0 | Details |
| US2162239A | Electric indicating device | Expired / Lapsed | 1937-03-10 | 1939-06-13 | 0 | Details |
| US2160853A | Reflector arrangement | Expired / Lapsed | 1936-03-25 | 1939-06-06 | 0 | Details |
| US2159792A | Relaxation oscillation generator | Expired / Lapsed | 1937-06-02 | 1939-05-23 | 0 | Details |
| US2158156A | Ball bearing and balls of ceramic material | Expired / Lapsed | 1937-10-01 | 1939-05-16 | 0 | Details |
| US2158314A | Cathode ray tube | Expired / Lapsed | 1936-07-15 | 1939-05-16 | 0 | Details |
| US2157576A | Arrangement of oscillation crystals | Expired / Lapsed | 1937-06-18 | 1939-05-09 | 0 | Details |
| US2157533A | Oscillator | Expired / Lapsed | 1937-06-08 | 1939-05-09 | 0 | Details |
| US2157665A | Crystal mounting with temperature compensation | Expired / Lapsed | 1936-10-17 | 1939-05-09 | 0 | Details |
| US2156653A | Ultra short wave system | Expired / Lapsed | 1936-05-22 | 1939-05-02 | 0 | Details |
| US2155509A | Electro-optical signaling | Expired / Lapsed | 1936-09-29 | 1939-04-25 | 0 | Details |
| US2153628A | Electron tube | Expired / Lapsed | 1936-03-17 | 1939-04-11 | 0 | Details |
| US2153752A | Direct current amplifier circuits | Expired / Lapsed | 1935-08-03 | 1939-04-11 | 0 | Details |
| US2153172A | Transmitter tube circuit | Expired / Lapsed | 1936-05-27 | 1939-04-04 | 0 | Details |
| US2151765A | Device for generating electrical oscillations | Expired / Lapsed | 1937-03-10 | 1939-03-28 | 0 | Details |
| US2151323A | Radio apparatus for determining distance and direction | Expired / Lapsed | 1936-05-23 | 1939-03-21 | 0 | Details |
| US2151336A | Radio signaling apparatus | Expired / Lapsed | 1935-07-05 | 1939-03-21 | 0 | Details |
| US2146994A | Television screen | Expired / Lapsed | 1937-01-09 | 1939-02-14 | 0 | Details |
| US2146769A | Separately controlled relaxation oscillator | Expired / Lapsed | 1933-10-23 | 1939-02-14 | 0 | Details |
| US2145676A | Multiwave range receiver | Expired / Lapsed | 1936-11-17 | 1939-01-31 | 0 | Details |
| US2144836A | Arrangement for duplex operation | Expired / Lapsed | 1937-02-19 | 1939-01-24 | 0 | Details |
| US2144222A | Electron discharge device | Expired / Lapsed | 1936-06-26 | 1939-01-17 | 0 | Details |
| US2143390A | Electron tube | Expired / Lapsed | 1935-01-05 | 1939-01-10 | 0 | Details |
| US2140016A | Wave meter | Expired / Lapsed | 1937-09-25 | 1938-12-13 | 0 | Details |
| US2139467A | Serrated wave form generator | Expired / Lapsed | 1936-10-30 | 1938-12-06 | 0 | Details |
| US2139432A | Oscillation producing system | Expired / Lapsed | 1936-01-30 | 1938-12-06 | 0 | Details |
| US2138138A | Transmitter circuit | Expired / Lapsed | 1936-11-21 | 1938-11-29 | 0 | Details |
| US2137118A | Fluorescent screen | Expired / Lapsed | 1934-12-06 | 1938-11-15 | 0 | Details |
| US2137202A | Electron tube | Expired / Lapsed | 1934-07-20 | 1938-11-15 | 0 | Details |
| US2135740A | Serrated wave form generator | Expired / Lapsed | 1935-12-20 | 1938-11-08 | 0 | Details |
| US2131185A | Electrooptical device | Expired / Lapsed | 1936-02-24 | 1938-09-27 | 0 | Details |
| US2131443A | Signaling | Expired / Lapsed | 1934-05-16 | 1938-09-27 | 0 | Details |
| US2130389A | Antenna | Expired / Lapsed | 1936-06-05 | 1938-09-20 | 0 | Details |
| US2130132A | Magnetron | Expired / Lapsed | 1937-07-01 | 1938-09-13 | 0 | Details |
| US2130124A | Electron discharge device | Expired / Lapsed | 1936-10-28 | 1938-09-13 | 0 | Details |
| US2128750A | Ultra-short wave receiving apparatus | Expired / Lapsed | 1937-10-28 | 1938-08-30 | 0 | Details |
| US2128395A | Measuring instrument | Expired / Lapsed | 1937-05-19 | 1938-08-30 | 0 | Details |
| US2125953A | Receiver of telephonic or telegraphic signals | Expired / Lapsed | 1937-05-28 | 1938-08-09 | 0 | Details |
| US2124191A | Demodulation system in superheterodyne receiver | Expired / Lapsed | 1936-09-25 | 1938-07-19 | 0 | Details |
| US2124404A | Television scanning system | Expired / Lapsed | 1934-03-08 | 1938-07-19 | 0 | Details |
| US2122893A | Conductor for radio frequency currents | Expired / Lapsed | 1933-07-08 | 1938-07-05 | 0 | Details |
| US2119115A | Mica condenser | Expired / Lapsed | 1934-11-08 | 1938-05-31 | 0 | Details |
| US2118419A | Ultrashort wave reflector | Expired / Lapsed | 1932-09-15 | 1938-05-24 | 0 | Details |
| DE660398C | Tube assembly using a shunt adjustable permanent magnet | Expired / Lapsed | 1934-02-24 | 1938-05-21 | 0 | Details |
| US2117858A | Screen material | Expired / Lapsed | 1934-12-19 | 1938-05-17 | 0 | Details |
| US2116717A | Distance and direction determining system | Expired / Lapsed | 1935-06-25 | 1938-05-10 | 0 | Details |
| US2115789A | Directional antenna system | Expired / Lapsed | 1936-05-22 | 1938-05-03 | 0 | Details |
| US2116217A | Visual indicator for tuning means | Expired / Lapsed | 1935-09-19 | 1938-05-03 | 0 | Details |
| US2115521A | Magnetron | Expired / Lapsed | 1937-04-07 | 1938-04-26 | 0 | Details |
| US2115373A | Tube changing device | Expired / Lapsed | 1934-12-01 | 1938-04-26 | 0 | Details |
| US2112283A | Direction finding system | Expired / Lapsed | 1936-06-25 | 1938-03-29 | 0 | Details |
| US2112282A | Ultrashort wave antenna system | Expired / Lapsed | 1935-08-10 | 1938-03-29 | 0 | Details |
| US2111778A | Fading elimination | Expired / Lapsed | 1934-08-23 | 1938-03-22 | 0 | Details |
| US2111595A | Control arrangement for energy leads | Expired / Lapsed | 1934-07-21 | 1938-03-22 | 0 | Details |
| US2110911A | Electron tube | Expired / Lapsed | 1934-07-27 | 1938-03-15 | 0 | Details |
| FR825438A | Improvements to radiobeacons | Expired / Lapsed | 1937-08-10 | 1938-03-03 | 0 | Details |
| US2106159A | Automobile radio apparatus | Expired / Lapsed | 1936-01-31 | 1938-01-25 | 0 | Details |
| US2103357A | Ultrashort wave system | Expired / Lapsed | 1936-07-18 | 1937-12-28 | 0 | Details |
| US2103358A | Method of eliminating reradiation | Expired / Lapsed | 1935-03-13 | 1937-12-28 | 0 | Details |
| US2102150A | Diaphragm | Expired / Lapsed | 1935-12-26 | 1937-12-14 | 0 | Details |
| US2101525A | Linear amplifier circuit | Expired / Lapsed | 1934-12-18 | 1937-12-07 | 0 | Details |
| US2100156A | Phase modulation | Expired / Lapsed | 1936-01-21 | 1937-11-23 | 0 | Details |
| US2099300A | Oscillation generator | Expired / Lapsed | 1936-05-07 | 1937-11-16 | 0 | Details |
| US2098370A | Automatic control of amplification | Expired / Lapsed | 1935-10-28 | 1937-11-09 | 0 | Details |
| US2097072A | Transmitter arrangement for guiding airplanes | Expired / Lapsed | 1935-03-09 | 1937-10-26 | 0 | Details |
| US2086742A | Radio receiving system | Expired / Lapsed | 1935-07-17 | 1937-07-13 | 0 | Details |
| US2085798A | Radio system for locating objects | Expired / Lapsed | 1936-06-12 | 1937-07-06 | 0 | Details |
| US2086271A | Electron discharge device | Expired / Lapsed | 1935-07-10 | 1937-07-06 | 0 | Details |
| US2086229A | Radio receiving system | Expired / Lapsed | 1935-04-30 | 1937-07-06 | 0 | Details |
| US2085905A | Circuit arrangement for regulating transmission measure in … | Expired / Lapsed | 1934-09-12 | 1937-07-06 | 0 | Details |
| US2085022A | Method of tuning receivers operating on potential resonance | Expired / Lapsed | 1935-04-15 | 1937-06-29 | 0 | Details |
| US2084836A | Alternating current meter | Expired / Lapsed | 1936-03-04 | 1937-06-22 | 0 | Details |
| US2084867A | Magnetically biased electron discharge device | Expired / Lapsed | 1935-03-01 | 1937-06-22 | 0 | Details |
| US2076289A | Frequency modulation | Expired / Lapsed | 1933-11-10 | 1937-04-06 | 0 | Details |
| US2073701A | Time-lag cathode circuit arrangement | Expired / Lapsed | 1934-04-10 | 1937-03-16 | 0 | Details |
| US2072637A | Electron discharge tube | Expired / Lapsed | 1933-10-26 | 1937-03-02 | 0 | Details |
| FR809012A | Method and systems for distance measurement by reflection o… | Expired / Lapsed | 1936-08-05 | 1937-02-22 | 0 | Details |
| US2065826A | Signaling | Expired / Lapsed | 1934-02-03 | 1936-12-29 | 0 | Details |
| US2064981A | Braun tube for television receiver apparatus | Expired / Lapsed | 1934-03-06 | 1936-12-22 | 0 | Details |
| US2063093A | Frequency multiplier circuits | Expired / Lapsed | 1933-08-19 | 1936-12-08 | 0 | Details |
| US2061733A | Thermionic device | Expired / Lapsed | 1933-08-29 | 1936-11-24 | 0 | Details |
| US2059587A | Oscillation generator | Expired / Lapsed | 1934-02-09 | 1936-11-03 | 0 | Details |
| US2057857A | Variable-gain amplifier arrangement | Expired / Lapsed | 1933-12-13 | 1936-10-20 | 0 | Details |
| FR802756A | Modulation process | Expired / Lapsed | 1936-02-27 | 1936-09-15 | 0 | Details |
| US2054659A | Electric condenser | Expired / Lapsed | 1934-10-04 | 1936-09-15 | 0 | Details |
| US2050737A | Light translating apparatus | Expired / Lapsed | 1933-07-03 | 1936-08-11 | 0 | Details |
| US2049677A | Heterodyne receiver | Expired / Lapsed | 1932-12-30 | 1936-08-04 | 0 | Details |
| US2046849A | Antenna system | Expired / Lapsed | 1935-07-17 | 1936-07-07 | 0 | Details |
| US2042606A | Variable resistor unit | Expired / Lapsed | 1933-05-11 | 1936-06-02 | 0 | Details |
| US2036833A | Tuning condenser arrangement | Expired / Lapsed | 1931-08-06 | 1936-04-07 | 0 | Details |
| US2034769A | Fading elimination | Expired / Lapsed | 1930-07-28 | 1936-03-24 | 0 | Details |
| US2033937A | Receiver for ultra short waves | Expired / Lapsed | 1934-07-19 | 1936-03-17 | 0 | Details |
| US2034520A | Radio receiver arrangement for landing aircraft | Expired / Lapsed | 1933-04-17 | 1936-03-17 | 0 | Details |
| US2031072A | Method of and means for signaling | Expired / Lapsed | 1932-05-05 | 1936-02-18 | 0 | Details |
| US2027193A | Thermostat arrangement | Expired / Lapsed | 1933-09-15 | 1936-01-07 | 0 | Details |
| US2023436A | Arrangement for producing rectangular alternating currents | Expired / Lapsed | 1933-02-17 | 1935-12-10 | 0 | Details |
| US2019765A | Frequency stabilization | Expired / Lapsed | 1932-12-07 | 1935-11-05 | 0 | Details |
| US2015178A | Method for the stabilization of electromagnetic oscillations | Expired / Lapsed | 1933-12-08 | 1935-09-24 | 0 | Details |
| US2014781A | Electron discharge device | Expired / Lapsed | 1935-02-07 | 1935-09-17 | 0 | Details |
| US2014509A | Radioreceiver | Expired / Lapsed | 1932-06-06 | 1935-09-17 | 0 | Details |
| US2008286A | Circuit connection for ultra short waves | Expired / Lapsed | 1932-08-26 | 1935-07-16 | 0 | Details |
| US2005798A | Directional apparatus | Expired / Lapsed | 1930-05-31 | 1935-06-25 | 0 | Details |
| US2004177A | Light amplifier | Expired / Lapsed | 1932-01-19 | 1935-06-11 | 0 | Details |
| US2002667A | Electron discharge device | Expired / Lapsed | 1934-06-23 | 1935-05-28 | 0 | Details |
| US2002181A | Transmitter | Expired / Lapsed | 1931-07-07 | 1935-05-21 | 0 | Details |
| US1996737A | Quartz oscillator arrangement | Expired / Lapsed | 1932-04-14 | 1935-04-09 | 0 | Details |
| US1997479A | Photoconductive device and method of making it | Expired / Lapsed | 1931-11-05 | 1935-04-09 | 0 | Details |
| US1997084A | Regenerative tube generator | Expired / Lapsed | 1931-04-02 | 1935-04-09 | 0 | Details |
| US1997263A | Method of manufacturing thin dielectric materials for high … | Expired / Lapsed | 1929-07-03 | 1935-04-09 | 0 | Details |
| US1996492A | Television apparatus | Expired / Lapsed | 1932-01-05 | 1935-04-02 | 0 | Details |
| US1994076A | Temperature control | Expired / Lapsed | 1932-03-02 | 1935-03-12 | 0 | Details |
| US1994228A | Temperature control of piezo-electric crystal apparatus | Expired / Lapsed | 1932-02-16 | 1935-03-12 | 0 | Details |
| US1992433A | Receiver volume control | Expired / Lapsed | 1929-10-28 | 1935-02-26 | 0 | Details |
| US1990649A | Transmitting or receiving arrangement for concentrated elec… | Expired / Lapsed | 1932-12-01 | 1935-02-12 | 0 | Details |
| US1988605A | Luminescent screen | Expired / Lapsed | 1932-08-19 | 1935-01-22 | 0 | Details |
| US1978818A | Frequency stabilization | Expired / Lapsed | 1931-01-31 | 1934-10-30 | 0 | Details |
| US1977999A | Cathode ray oscillograph | Expired / Lapsed | 1933-03-16 | 1934-10-23 | 0 | Details |
| DE604078C | Ammeter | Expired / Lapsed | 1932-08-21 | 1934-10-13 | 0 | Details |
| US1976400A | Cathode ray scanning device | Expired / Lapsed | 1931-05-21 | 1934-10-09 | 0 | Details |
| US1971383A | Transmitter | Expired / Lapsed | 1933-02-15 | 1934-08-28 | 0 | Details |
| US1969328A | Radio transmitting circuit | Expired / Lapsed | 1932-05-04 | 1934-08-07 | 0 | Details |
| US1969379A | Apparatus for making piezo-electric bodies | Expired / Lapsed | 1929-11-12 | 1934-08-07 | 0 | Details |
| US1965632A | Means for measuring distances | Expired / Lapsed | 1930-11-18 | 1934-07-10 | 0 | Details |
| US1960006A | Antenna system | Expired / Lapsed | 1931-12-18 | 1934-05-22 | 0 | Details |
| US1955093A | Oscillation circuit for electric waves | Expired / Lapsed | 1930-07-07 | 1934-04-17 | 0 | Details |
| US1937131A | Facsimile signaling system | Expired / Lapsed | 1931-02-20 | 1933-11-28 | 0 | Details |
| US1934211A | Receiving arrangement for radiosignals | Expired / Lapsed | 1929-01-30 | 1933-11-07 | 0 | Details |
| US1932469A | Short wave signaling | Expired / Lapsed | 1930-12-02 | 1933-10-31 | 0 | Details |
| DE585406C | Drive device for wire-shaped sound carriers by means of a r… | Expired / Lapsed | — | 1933-10-03 | 0 | Details |
| US1928765A | Method and means for wave measurement | Expired / Lapsed | 1928-09-19 | 1933-10-03 | 0 | Details |
| DE584954C | Device for remote monitoring of measuring instruments | Expired / Lapsed | 1927-02-24 | 1933-09-27 | 0 | Details |
| US1921869A | Method of and means for making coils possessing accurate in… | Expired / Lapsed | 1930-09-19 | 1933-08-08 | 0 | Details |
| US1917739A | Electric discharge device | Expired / Lapsed | 1931-03-13 | 1933-07-11 | 0 | Details |
| DE577480C | Magnetic sound carrier | Expired / Lapsed | 1929-08-10 | 1933-05-31 | 0 | Details |
| US1911091A | Signaling | Expired / Lapsed | 1929-09-03 | 1933-05-23 | 0 | Details |
| US1909365A | Method of making fluorescent screens | Expired / Lapsed | 1930-02-11 | 1933-05-16 | 0 | Details |
| US1908191A | Stabilizing glow-discharge tubes | Expired / Lapsed | 1927-09-07 | 1933-05-09 | 0 | Details |
| US1898661A | Antenna system | Expired / Lapsed | 1931-10-29 | 1933-02-21 | 0 | Details |
| US1898477A | Fading elimination | Expired / Lapsed | 1929-12-16 | 1933-02-21 | 0 | Details |
| US1897219A | Apparatus for photoelectric exploration by reflection metho… | Expired / Lapsed | 1929-01-31 | 1933-02-14 | 0 | Details |
| US1892221A | Polarization diversity reception | Expired / Lapsed | 1929-01-30 | 1932-12-27 | 0 | Details |
| US1886234A | Method of making high grade dielectric materials | Expired / Lapsed | 1928-11-19 | 1932-11-01 | 0 | Details |
| US1880102A | Light control arrangement | Expired / Lapsed | 1926-07-02 | 1932-09-27 | 0 | Details |
| US1875165A | Method for wireless communication | Expired / Lapsed | 1928-06-11 | 1932-08-30 | 0 | Details |
| US1867179A | Telegraphone | Expired / Lapsed | 1930-10-09 | 1932-07-12 | 0 | Details |
| US1863798A | Circuit arrangement for transmitter tubes | Expired / Lapsed | 1927-01-25 | 1932-06-21 | 0 | Details |
| DE551550C | Drive device for wire-shaped sound carriers by means of a t… | Expired / Lapsed | 1930-08-28 | 1932-06-02 | 0 | Details |
| US1860050A | Oscillation generator | Expired / Lapsed | 1929-10-01 | 1932-05-24 | 0 | Details |
| US1843981A | Light control means | Expired / Lapsed | 1927-08-05 | 1932-02-09 | 0 | Details |
| US1841639A | Coupling | Expired / Lapsed | 1929-08-31 | 1932-01-19 | 0 | Details |
| US1819469A | Radio system | Expired / Lapsed | 1926-02-01 | 1931-08-18 | 0 | Details |
| US1792756A | Modulation system | Expired / Lapsed | 1925-10-22 | 1931-02-17 | 0 | Details |
| US1791938A | Safety device for railroad operation | Expired / Lapsed | 1929-11-16 | 1931-02-10 | 0 | Details |
| DE516783C | Arrangement for melting the surface of dielectric bodies | Expired / Lapsed | — | 1931-01-29 | 0 | Details |
| US1789369A | Means for indicating changes in gases | Expired / Lapsed | 1927-06-30 | 1931-01-20 | 0 | Details |
| US1773556A | Oscillation generation | Expired / Lapsed | 1925-07-22 | 1930-08-19 | 0 | Details |
| US1746407A | Facsimile-transmitting arrangement | Expired / Lapsed | 1928-03-31 | 1930-02-11 | 0 | Details |
| US1738684A | Voltage-limiting arrangement for intermediate-circuit trans… | Expired / Lapsed | 1924-12-15 | 1929-12-10 | 0 | Details |
| US1737169A | Controlling means on current conductors for high-frequency … | Expired / Lapsed | 1925-10-23 | 1929-11-26 | 0 | Details |
| US1735134A | Method and system for constant-frequency beat reception of … | Expired / Lapsed | 1926-05-13 | 1929-11-12 | 0 | Details |
| US1708530A | Apparatus for the generation of short electrical waves | Expired / Lapsed | 1925-07-15 | 1929-04-09 | 0 | Details |
| US1708544A | Method and arrangement for electrical measurements | Expired / Lapsed | 1925-04-06 | 1929-04-09 | 0 | Details |
| DE467594C | Method of manufacturing piezo-electric plates | Expired / Lapsed | 1927-07-28 | 1928-10-26 | 0 | Details |
| US1672856A | Rotary condenser | Expired / Lapsed | 1926-05-04 | 1928-06-05 | 0 | Details |
| DE353297C | Arrangement to heat wires, especially in cathode tubes, to … | Expired / Lapsed | — | 1922-05-13 | 0 | Details |
| US1077733A | Means for producing slightly-damped oscillations by shock e… | Expired / Lapsed | 1910-06-07 | 1913-11-04 | 0 | Details |
| US962262A | Wave-detector for wireless telegraphy. | Expired / Lapsed | 1906-04-14 | 1910-06-21 | 0 | Details |
| US958181A | Receiver for wireless telegraphy. | Expired / Lapsed | 1906-08-31 | 1910-05-17 | 0 | Details |