In fact, the light bulb wasn't invented only by Thomas Edison. The firts person who started thinking about it was Frederic de Moleints in 1841. The begining was not rewarding, because his invention worked very short.

Better known is Heinrich Grüber who allegedly created his own verson of light bulbs but it wasn't truth.

Joseph Swan made a big step in improving light bulbs. They was made of carbon fiber and shone thirteen and half hour. That result was quite good but there was a problem with mount. When Edison was making the final product he was taking pattern from Swan's invention and created the best light bulb.