Thomas Edison of the Edison patent to charge a more reasonable rate for the use of the Edison patent rights and lowering the price of the electric lamp. On October 8, 1883, the US patent office ruled that Edison's patent was based on the work of William E. Sawyer and was, therefore, invalid. Litigation continued for nearly six years, until October 6, 1889, when a judge ruled that Edison's electric light improvement claim for "a filament of carbon of high resistance" was valid. To avoid a possible court battle with Joseph Swan, whose British patent had been awarded a year before Edison's,
Moscow Electric Lamp Plant Moscow Electric Lamp Plant Moscow Electric Lamp Plant () is a company based in Moscow, Russia. The Moscow Electric Lamp Production Association has been a leader in the development and production of vacuum tubes for both civil and military use. It is a major producer of cathode ray tubes (CRTs) for color television receivers, and for many years was one of the largest producers in Russia of photoelectronic multiplier tubes (used in light sensing devices). The Association includes three major production facilities: the Moscow Electrovacuum Instrument Plant, which is co-located with the association; the Khromatron Plant, located elsewhere in Moscow;