| 摘要 |
A mechanism for selectively positioning a plurality of different lens units along the optical center-line of a photographic printer. The lens units are mounted on a common carrier and are successively moved into alignment along the optical center-line in response to overall movement of the common carrier, such as along a path that is oblique to the optical center-line. The plurality of different lens units are typically arranged substantially horizontally with respect to one another on the common carrier, and typically include a plurality of lenses having different powers of magnification of focal lengths. The common carrier engages a threaded drive bar disposed substantially parallel to the path that is oblique to the optical center-line to produce movement of the common carrier in relation to the optical center-line. The drive system cooperates with a guide means to retain the original orientation of the common carrier as the common carrier moves along the oblique path. A mask operates to isolate the remaining lens units from the photographic printer. The invention herein further includes an invention methodology for exposing a photographic print on an elongated web of photographic paper from an elongated strip of photographic negative images in a photographic printer using the mechanism previously described.
|
