Film cartridges, films and cameras adapted for use therewith

摘要

Disclosed are film cartridges having improved digital code patterns, films having improved digital signal means, and camera devices adapted for use with the film cartridges or the films. The improved code patterns include bits with different weights and a bit which is made conductive with at least one of the bits with the different weights. One of the camera devices is provided with a reading device on a spool so that the reading device can continuously read the signal means at a front tip of a leader portion of the film throughout the duration in which the film is wound around the spool. Another camera device is adapted to read the code patterns on the film cartridge upon insertion of the film cartridge into a cartridge chamber. Various camera circuits are proposed, in one of which decimal or fractional APEX values of read film speeds are converted to outputs with weights of 1/2, 1/4 and 1/8 for digital calculation and in another of which film speeds divided by 1/3 Ev steps are automatically set by being grouped into one of high, middle and low film speed ranges.