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,
Henry Woodward (inventor) necessary components to make the first practical electric light bulb. What is known about Woodward's discovery is that it was patented in Canada and the United States prior to a patent being granted to Edison and it is known that the patent for the Canadian discovery was purchased by Edison when he was making his original investigations and before he obtained his patent. Ricketts, Bruce. The First Electric Light Bulb Henry Woodward (inventor) Henry Woodward was a Canadian inventor and a major pioneer in the development of the incandescent lamp. On July 24, 1874, Woodward and his partner, Mathew Evans,