| 摘要 |
<p>When a filmstrip (F) is completely exposed in a camera (101), double-exposure prevention DEP data is magnetically applied to the film leader (43) substantially immediately before the leader is rewound with the filmstrip into a light-tight cassette (1). The DEP data indicates there are no unexposed imaging areas remaining on the filmstrip. If the filmstrip is rewound into the cassette prematurely, i.e. without it being completely exposed, midroll interrupt MRI data is magnetically applied to the film leader instead of the DEP data to indicate the next-available unexposed imaging area of the filmstrip. When the cassette is re-loaded into the camera, the film leader is advanced from the cassette initially to determine whether it is encoded with DEP or MRI data. If the DEP data is detected, the leader is rewound into the cassette since all of the imaging areas of the filmstrip are exposed. If the MRI data is detected, the filmstrip is advanced from the cassette to locate the next-available unexposed imaging area in an exposure position. Warning means (149, 151), responsive to the sensing of the DEP data or the MRI data, provides a visible and/or audible signal that a completely used or partially used film roll has been loaded in the camera.</p> |
