| 摘要 |
Apparatus for holding a projection lens assembly of a reader in precise position relative to a transparency, the transparency being a platelike film containing a plurality of reduced images thereon. The lens assembly includes a condenser-type lens for magnifying and for projecting the image in an enlargement thereof onto a screen for viewing the enlarged image, the lens assembly being maintained against the surface of a predetermined image plane by reason of a lens-containing tracking sleeve being spring-urged into contact with the image plane. The lens assembly is spaced from a supporting member by ring means surrounding the tracking sleeve, which permits pivotal action at the nodal point of the lens, to maintain the axis of the lens assembly perpendicular to the image plane for all image-projecting positions of the transparency.
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