| 摘要 |
PURPOSE:To improve an operability in seeing an index or a list, etc., by turning back a microfilm to a head information frame, and stopping it, when an operation key for turning back one case portion is operated after retrieval of a head frame provided with a case mark. CONSTITUTION:A retrieval controlling circuit 90 uses a microcomputer of one chip, having a central processor, an ROM being a program memory, an RAM being a data memory etc. inside. In case of retrieval of a frame, after a head frame provided with a case mark is retrieved, and a -1 case key 15 is turned on, a case retrieval switch 28 is checked if it is off, to turn back a film until contents of a counter obtain ''0001'', and is stopped. When the case retrieval switch is on, contents of the counter are not checked and only a mark of the case is checked. |
