| 摘要 |
A microfilm image reader apparatus for detecting an image on a microfilm strip and projecting the detected image onto a target plane, wherein a beam of light bearing an image detected from the microfilm strip is produced by illuminating the microfilm strip and is projected through a projection lens onto the target plane, and wherein an automatic mode of focus control is established through detection of a condition in which the image-bearing beam is focussed with respect to the target plane and, when it is detected that the automatic mode of focus control is inoperable, the projection lens is automatically moved to a position having its focal plane located on a predetermined plane with respect to the target plane and, after the projection lens is moved to such a position, the focal plane of the projection lens may be manually adjusted by the operator of the apparatus.
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