The textbooks in China have been written since childhood, “Edison invented the electric light”, but in fact the electric light was not invented by Edison, he just improved the electric light and had a patent.
As early as 1850, an Englishman named Swan began to study electric lights. In 1878, he invented the electric light “powered with carbon wire under vacuum”, patented in the UK, and founded the electric light company. In addition, in 1874, two Canadian electrical technicians applied for a patent for electric lights, but because they did not have enough funds to continue developing the invention, they sold the patent to Edison in 1875.
Later, Swan sued Edison for infringement of the patent and won the case. Later, Swan sold his rights and patents to Edison. In fact, Edison has many inventions to buy other people to buy patents, but it is undeniable that he is still indispensable in popularizing electric lights.