The first drum recorders and scanners appeared in the 1920's. These devices, built on a lathe bed, imaged manually loaded films. The imaging sources were glow modulator tubes and incandescent lamps with mechanical modulators. During the intervening decades semiconductors, lasers, air bearings, brushless motors, and computers have been used to improve the image quality and productivity of various output devices. In the 1960's and 70's, visionaries foresaw the day when lithographic printing plates would be imaged by laser energy modulated by computer generated data. That day has arrived.Today, newspapers and commercial printers employ automated CTP (Computer To Plate) devices to image metal and plastic printing plates. Several system approaches have been developed, each exploits the characteristics of one of the several plate types that have been introduced. Systems are available that use, UV, visible or IR lasers.This paper reviews some of the CTP innovations that have evolved to meet the demands for image quality, productivity, reduced cost and environmentally benign operation.
Robert M. Landsman, "CTP Productivity and Recorder Design" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP15), 1999, pp 204 - 208, https://doi.org/10.2352/ISSN.2169-4451.1999.15.1.art00053_1