On-line microfilm storage and retrieval system

Claim 1

A microfilm storage and retrieval system comprising: a) cartridge handling means for storing and retrieving microfilm cartridges comprising: i) a rotatable center column assembly including a vertical column; ii) a plurality of vertically stacked spoked hubs, each having a center ring disposed around the vertical column and from which a plurality of spokes extend, wherein the spokes form: A) a plurality of essentially equally-spaced gaps within each of which one of the microfilm cartridges may be stored; B) an additional gap larger than the equally-spaced gaps used to establish a rotational home position for the spider assembly and to establish a vertical column through which a selected one of the microfilm cartridges may pass through, iii) and rotation means for rotating a selected one of the vertically stacked spoked hubs so that a selected one of the equally-spaced gaps may be aligned within the vertical column so that the selected one of the microfilm cartridges may pass vertically through; b) a microfilm handling subsystem comprising: i) elevator means for transporting the selected one of the microfilm cartridges from the selected one of the equally-spaced gaps through the vertical column and to a display position including A) an elevator, and B) electrical lifting means for raising and lowering the elevator through the vertical column; ii) verification means for verifying that the spoked hub having the selected one of the equally-spaced gaps is the only one of the plurality of vertically-stacked spoked hubs rotated from its home position and for verifying that the elevator is below the selected one of the equally-spaced gaps; and c) a video image processing subsystem comprising: i) a projection means for projecting an image from a selected frame of microfilm onto a projection plane; ii) a scanning array means comprising a linear array of sensors for converting light intensities on the projection plane into proportional electrical voltages, iii) array moving means for moving the scanning array means through the projection plane, and iv) an image enhancement processor means to determine for each of the proportional electrical voltages whether a pixel represented thereby is a foreground or a background pixel; wherein each subsystem is accessible and controllable as part of a local area computer network.