1. Field of the Invention
The present invention relates to camera-processor apparatus for recording and developing images, e.g. of documents, and more particularly to such apparatus adapted for use with imaging media in a roll form, such as a long-strip of microfilm stored on a reel or cartridge.
2. Description of the Prior Art
The usual procedure for recording and processing document images on roll form recording media (e.g., microfilm rolls containing a film strip many feet in length) has been to first record a complete roll of images in a microfilm camera and then remove the roll and develop it in a separate processor. Besides requiring two separate pieces of equipment, this approach requires the operator to perform two separate operations before the image formation is completed. Operator time amounts to a considerable expense, and it would be desirable to record and develop the entire roll in one feed-through sequence. Also, there are occasions when it is desirable to see certain already-recorded portions of a roll before the entire roll has been recorded.
The development of various kinds of photothermographic films, i.e., ones developable using heat as opposed to processing liquids, has led to the design of various kinds of camera-processor apparatus which can record and develop a roll of film in a single feed-through operation.
In connection with simple step and repeat cameras, e.g., planetary microfilmers, a simple approach is to bring a heated platen into and out of contact with each individual film image just after its recording, during the pause for recording of the next image. Such a solution is not available in connection with continuous-flow cameras, e.g., rotary microfilmers, where the film and documents move continuously during recording.
One, more straightforward, approach for continuous-flow camera-processor is to provide a processing path, downstream from the exposure station, across a heated roller or platen. The processing path is of a sufficient length along the heating zone that adequate processing time is afforded to the film which is fed continuously thereover at the feed rate determined by the image recording operation. However, with this approach a problem exists when delays occur in the recording operation, e.g., if the operator pauses to rest briefly or needs to obtain more documents. When such recording delays occur, already recorded film that is downstream in the processing path also stops its movement, and it would be over-developed or burned if heating were not terminated. This problem has been avoided by retracting the heating means from its operating relation with the film when film feed stops. However, the chemistry of many photothermographic films is not compatible with a partial heat development followed by a pause and then the remainder of the "prescribed" heat processing period. Thus, poor image quality can result with respect to the film portions which reside in the processing section during such pauses.
An alternative approach disclosed in U.S. Pat. No. 4,158,496 allows uniform, continuous processing by accumulating segments of recorded film, severing them from the remainder of the strip and then feeding them completely through the processing section in a continuous manner. This avoids the problems of film pauses in the heat-processing section, but at the cost of cutting the film strip. Many applications use the entire roll as a continuous strip in storage and retrieval systems, and severing of the film at other than predetermined positions is not a desirable solution for those applications.