| 摘要 |
PURPOSE:To improve operability by giving an alarm while inhibiting a film from moving even if a key for moving back the film by one information frame group or one frame is pressed during the retrieval of the 1st information frame with a subject mark or during reset mark detection. CONSTITUTION:A microfilm 1 consists of plural information frames K1, K2- Kn, and each frame has a frame mark MK. When plural frames KG form one pieces of information, the starting frame has a subject mark Mcn. End parts are connected to leader tapes 1a and 1b with a start mark MS and an end mark M. A key at the input part of the retrieval device which is not shown in the figure is operated to access a desired information frame Ki, thereby projecting its information on a screen. In this case, even if operation for moving back the film by one group or one information frame is performed after during the retrieval of the 1st subject mark Mcl or after a reset mark (start mark) is detected, the film is not moved and a warning of the erroneous operation is generated. Thus, the operability is improved. |
