Film drive apparatus for a photographic film scanner

摘要

Film scanning apparatus having a film cartridge chamber for receiving a film cartridge containing photographic film having images to be scanned, a film takeup chamber and a film scan gate therebetween. The apparatus has an upstream nip roller set positioned between the film cartridge chamber and the film scan gate and includes at least one drive roller and pinch roller set in which the drive roller has a compliant film engagement surface. A downstream nip roller set is positioned between the film scan gate and the film takeup chamber and includes at least one drive roller and pinch roller set in which the drive roller has a compliant film engagement surface. The upstream nip roller set exerts constant tensioning force on film in the film scan gate buffering the film in the film scan gate against variable tensioning effects on the film caused by the film cartridge. A drive motor is directly connected to the downstream drive roller set and the downstream roller set is drivingly connected to the upstream drive roller set by an elastic drive belt. A differential compression force is exerted on the pinch rollers such that the force on the downstream pinch rollers is greater than on the upstream pinch rollers thereby causing a film speed differential between the upstream and downstream roller sets that maintains a desired degree of tension on film transported through the film scan gate.