How many of Edison's 1000 patents were really developed by himself?

Although Edison bought many invention patents from some poor scientists at low prices, some of them were forcibly obtained from scientists in his own company. But Edison was also a scientist. Since he is called a scientist, it means that he has his own research field and made some inventions. Therefore, some of his 1000 invention patents were obtained by his own research and invention.

As far as I know, there are two invention patents that he studied himself, namely, carbon filament light bulb and phonograph. Of course, there are more than these two patents.

Although Edison bought the light bulb as a patent, the carbon light bulb he later put into production was not the patent he bought from the first person who created the light bulb. The light bulb he later put into production was a carbon filament light bulb, which was the result of Edison's research and improvement on the basis of the original light bulb. Compared with other patents that directly label other people's inventions as their own, the carbon filament light bulb is indeed Edison's own invention.

In fact, it was not his early research that made Edison such a famous light bulb. The phonograph was an invention patent of Edison when he was young. At that time, Edison was really a talented person. He was constantly exploring and inventing something. Trying to get away from the sound is very different from ordinary people. But Edison didn't get rich from the patent he invented, because he didn't make many changes to the phonograph after he invented it, and others have been studying it and achieved good results, so Edison's phonograph was eliminated.