| 摘要 |
As a long photographic film is developed in an automatic processor, the developing solution becomes weaker, resulting in underdevelopment at the latter end of the film. Under-development is prevented by reducing the drive-motor speed in proportion to the length of film which has been processed. The film (12) is fed through the developing tank(1) by motordriven rollers (3 and 4). Each rotation of the motor (11) triggers a pulse generator (13) which feeds a counter (14). The counter output, which is thus proportional to the length of film already processed, is fed to the motor regulator (15). The regulator reduces the motor speed as the developing solution (2) becomes weaker.
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