Digital Laser Platemaker Modifications

摘要

The Digital Laser Platemaker (LPM) is a high resolution, high accuracy system developed as a prototype to expose large format pressplate or film that is compatible with the Defense Mapping Agency lithographic production process. The LPM reads compressed digital data in raster format from magnetic tape. Through an electro-mechanical system, laser generated light is aimed and modulated to expose images on photosensitive media. A series of investigations were conducted on the Army's digital laser platemaker to identify and correct deficiencies and increase system overall operability. A new footbar was designed and installed which reduced media loading errors. Accuracy testing indicates that inter-image error is less than 0.002 inch, while intra-image error is not within tolerance. Testing results are encouraging that intra-image errors can be further reduced, but additional work is needed in the areas of accuracy testing and alignment of some of the optical components. While the existing machine is functional, there are several areas where components should be redesigned for a production model.