| 摘要 |
PURPOSE:To prevent a microfilm from being damaged in low-speed mode such as manual retrieval mode for a frame image by varying press-contacting force during the frame retrieval of a microfilm according to a conveyance speed. CONSTITUTION:When a switch S1 is turned on in manual retrieval mode over a look at a projection frame image on a screen, a switch S2 is turned off. A plunger 32A moves to a position III with the weak current of an exciting circuit. Press-contacting glass 20 is pressed against fixed glass 21 with weak force to hold the microfilm 2; an in-focus frame is projected and the microfilm 2 is pressed relatively gently, so its surface is not damaged even during frame movement for retrieval. When a desired frame image is retrieved, the S2 is turned on with the S1 on, and the microfilm 2 is held fixedly between the fixed glass 21 and press-contacting glass 20 with strong press-contacting force to project and copy the in-focus frame image.
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