Edison was a great inventor, but he was not the inventor of electric light. The inventor of the electric light is an Englishman, Swan. 1879, Swan invented the electric light, but he did not apply for a patent, but disclosed the method of making the electric light in a magazine. There is evidence that Edison "invented" the electric light after reading this magazine and immediately applied for a patent.
Please refer to Baidu Library "Why Not Say Edison Invented the Electric Light".