Who invented roll film and what year did he patent roll film?

The inventor of the 35mm roll-film camera was Oscar Barnack

Traditional still-Photography developed in the 19th century using large, cumbersome cameras and photographic plates. In the early 20th Century Oskar Barnack, an engineer at the German company Leitz, which made precision optical instruments such as microscopes, and who was a keen amateur photographer decided to do something about the size of the cameras. This was to a large part due to his physical frailty (he suffered badly from Asthma and found it difficult lugging the heavy photographic equipment about). He began experimenting with with cinematic film and a light meter which he adapted and improved.

At the time cinema cameras shot on 35mm film with a frame size of 18x24mm. Barnack found that this format produced poor quality still photographs and he doubled the frame size to 24x36mm. Originally the film was supplied on large reels (known as a roll) and had to be cut into manageable lengths and placed in the camera in absolute darkness but as the popularity of the format increased, re-loadable film cartridges were developed and eventually companies such as Agfa and Kodak began supplying the film to photographers in single-use cartridges.

With the development of the film cartridge the phrase 'roll of film' migrated to mean a cartridge of 35mm film. Over the years other formats and systems were spawned including medium format roll-film, 110 cartridge, Minox miniature format, APX and disk but thanks to the vision of Oskar Barnack and the versatility of the format he created the humble 35mm roll of film is the only one to stand the test of time.