Condition sensitive method and apparatus for imaging a lithographic printing plate

摘要

A platesetting method and apparatus provides for dimensional and/or exposure sensitivity changes in a printing plate to be imaged in a platesetter. A condition sensor senses the temperature of the plate prior to exposure so that a control unit can adjust the control commands to the scanning exposure mechanism of the platesetter in order to compensate for any thermal expansion or exposure sensitivity shifts. An image to be recorded onto the plate material has a standard size at a standard plate material temperature. When the plate material is at a non-standard temperature, as determined by the thermal sensor, a program, stored in memory, calculates a new image size based on the non-standard temperature and the thermal characteristics of the plate material which are also stored in memory. The imagesetter electronic controller then exposes an image having a size which will be the standard size when the plate material returns to the standard temperature.