| 摘要 |
872,886. Microphones; pick-ups. COSMOCORD Ltd. Nov. 14, 1957 [Dec. 4, 1956], No. 37008/56. Class 40 (4). [Also in Group XXXVI] A magneto-resistive transducer element of a microphone or pick-up comprises a strip of indium antimonide supported in a magnetic field with a substantial gradient. The resistance of the strip changes when the strip is displaced. A thin 1 layer of indium antimonide is deposited on a support 2 of glass. The strip is defined by a gap 4 between two silver electrodes 5, 6 laid over the antimonide. Terminal leads are attached to the electrodes by silver paint 7. The glass support is attached to a diaphragm or stylus. The electrodes 5, 6 and the antimonide layer 1 may be divided along lines 10, 11, 12, Fig. 2, to provide a circuit through four elements in series. The magnetic field is provided by a permanent magnet with pole pieces 8, 9. The layer 1 of indium antimonide may be deposited by vacuum deposition, cathode sputtering, spraying, spreading or by a combined photographic and etching process. |
