Process and apparatus for automatic measurement of density of photopolymer printing plates

A method for checking quality of a mask creation system in a system for preparing a printing plate comprising a photosensitive polymer activated by exposure to radiation, the printing plate having a non-printing back side and a printing front side having a mask embodying image information corresponding to an image to be printed, the method comprising the steps of:

• a) positioning a density measurement system relative to the printing plate, the density measurement system comprising:
• a first radiation source spaced apart from and adjacent the plate and configured to emit a first radiation having a first wavelength or range of wavelengths toward the plate;
• a densitometer spaced apart from and adjacent the plate in a fixed relationship relative to the first radiation source, the densitometer configured to receive and measure an amount of the first radiation transmitted through or reflected by the plate and the mask;
• b) causing relative movement between the printing plate and the density measurement system while the first radiation source emits the first radiation and the densitometer receives and measures the amount of the first radiation transmitted through or reflected by the plate and the mask;
• and
• c) processing information from the densitometer relating to the amount of measured radiation received over a predetermined region of the printing plate and providing an output correlating to quality of the mask based upon the processed information.