| 摘要 |
PURPOSE:To retrieve tghe desired information in a short time by feeding a film at a low speed when a blank part which contains no information with length larger than the rpescribed value is detected and then at a high speed when a mark is detected during the feed of the film at a low speed. CONSTITUTION:A speed switching circuit 16 receives the output signals of a comparator 14, the 1st timer and a detector 12 and controls the driving speed of a film feeding motor 17 in response to those received output signals. The frame number of the desired information to be retrieved is supplied to a keyboard 10 together with a retrieving instruction. Under such conditions, a drive signal is outputted from the comparator 14 is case no coincidence is obtained between the contents of a counter 13 and those of a memory circuit 11. In case a large blank part is produced between frames in a high-speed driving mode, a flip-flop circuit 20 is set. Then a low-speed driving signal is outputted from an OR gate circuit 22. Thus a film is driven at a low speed.
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