| 摘要 |
A film cassette comprises a spool rotatable to thrust a filmstrip coiled about the spool out of the cassette shell, and an exposure status indicator rotatable from an unexposed position to an exposed position for providing respective indications that the filmstrip is unexposed or is exposed. According to the invention, a shroud substantially surrounds a circumferential edge of the status indicator to prevent one from manually grasping the edge in order to rotate the indicator from its unexposed position to its exposed position. However, the shroud allows a top face of the status indicator to be accessed by an actuating mechanism in a camera, for example, to rotate the indicator from the unexposed position to the exposed position. The shell and the status indicator include respective engagement means that lock responsivee to a force applied downwardly to the top face of the indicator to prevent one from rotating the indicator from its unexposed position to its exposed position by pressing against the top face and attempting to rotate the indicator. Normally, the engagement means are unlocked to allow the status indicator to be rotated from the unexposed position to the exposed position by the actuating mechanism.
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