Camera with automatic film initialization responsive to cartridge sensor

摘要

In a low cost camera, film initialization to a first exposure frame by a time constant controlled drive circuit in which the time constant circuit is reset by a "cartridge present" sensor switch as a consequence of removing a film cartridge from the camera. This ensures that newly loaded film will be automatically initialized to the first exposure position without requiring the camera user to remember to actuate a shutter release button multiple times to achieve proper initialization. A flash charger circuit in the camera is automatically started at the end of frame advance or at the end of film initialization by opening of a film metering sensor switch that allows discharge of a capacitor into the time constant circuit, capacitor discharge generating a starting pulse sent to the charger circuit.