Determination of Technical Parameters in CTP Process and its Image Quality

The focal length, zoom, irradiating power and cylinder speed of laser head influence the exposure quality directly in computer-to-plate (CTP) process. This paper determined the most optimal parameters which used screen thermal sensitive device PT-R4100 by changing the focal length, zoom, irradiating power and cylinder speed of laser head. The most optimal parameters of focal length, zoom, irradiating power and cylinder speed in CTP process were 1500puls, 6700puls, 90%, 600r/min respectively。Compared with computer-to-film (CTF), we found that the image quality of CTP process was better. The average density, register accuracy and ink trapping of CTP process were higher than that of CTF. Ink formation was also better.