| 摘要 |
<p>Apparatus for holding film strips (14) of the type having a plurality of miniaturized film images (152) carried thereon, wherein the apparatus is to be used with an optical system (34) which illuminates and projects the images on an enlarged scale so that they can be viewed on a projection screen. The apparatus includes a rotary film holder (12) or cassette having a number of concentric cylindrical segments (16, 18) defining a pair of coaxial cylinders, the segments being provided with grooves (20) to permit insertion of a plurality of film strips (14) in the cassette. The inner segments (16) are longer than the outer segments (18) so that portions of the radially outermost edges of the film strips (14) are exposed and the outer edge of a selected film strip can be engaged by an edge drive wheel (70) to permit the selected film strip to be moved partially out of and to be returned to the cassette. The cassette is rotatably mounted by spaced bearings (21) on a projection (36) carried by a stationary support (32), and a drive wheel (51) coupled to a reversible motor (55) engages the outer periphery of the cassette to rotate it in opposed directions. An optical system (34) on the support is used with an X-Y drive (35) to project an image on the selected film strip onto a screen when the film strip is releaseably held in a predetermined focal plane by hold-down means (122). Control structure (190) coupled with the drive motors of the cassette, the edge drive wheel and the X-Y drive controls such motors to effect operation of the apparatus. </p> |
