Artwork generation apparatus and process for charts

摘要

An apparatus and automated process to improve the accuracy and reduce the time, cost, and effort necessary to prepare reproduction artwork for charts is disclosed. A numerically or computer controlled imaging system is used to expose photographic film or emulsion with specially prepared halftone pattern symbols. This allows a computer to be used to select both the symbol and location, instead of slow and costly manual methods. Greatest benefits accrue when the final chart is to be in color. One sheet of film per primary color is exposed using a few basic symbols, which are then combined to yield a wide range of color in the symbols of the final chart. Typically, the final product of this process is one or more sheets of monochromatic film used as masters for a color printing or color key process. Further, a method is described to avoid erroneous density (and resultant color) changes where halftone symbols overlap, as well as various other methods to improve legibility and produceability of the charts.