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,
Philip Diehl (inventor) patents issued to Philip Diehl: Diehl erected the city's first arc light in front of the Corey Building in Elizabeth, which still stands at 109 Broad Street. Diehl's invention of the induction lamp was used by George Westinghouse to force royalty concessions from Thomas Edison. The Westinghouse Company bought Diehl's patent rights for $25,000. Although Diehl's lamp could not be made and sold at a price to compete with the Edison lamp, the Westinghouse Company used the Diehl bulb to force the holders of the Edison patent to charge a more reasonable rate for the use of the Edison patent