| 摘要 |
<p>The information retrieval system uses key words as the basis for marking locations on a grid to identify sources related to the chosen key word. The grid is on photographic film, allowing optical scanning, cheap and accurate reproduction, variations in the dimension of the film used to hold the data, and reversal to allow either light transmission or observation as the detection method. To facilitate scanning of the data, a device using a cursor which moves along locating holes on a table which holds the film in a fixed location is employed. Pockets on the cursor hold a label with the keyword written on it, and the film is prepared in strips relating to a single key word. By moving the cursor over the film marked points of the grid may be detected and displayed on, for example, a microfilm reader screen.</p> |
