Prepress
1600 mW Violet Laser Application – made by DotLine GmbH
Thursday 11. December 2008 - DotLine GmbH finished in these days the development of a new optical system with 4 x 400 mW violet-diode-laser (405nm). The system is developed to expose optical measuring tapes with sub-µm tolerances.
The specialists in DotLine for laser technology and the use for exposing of photosensitive material hand over the worldwide unique exposing unit with 1600mW laser power.
Core piece of the optical system, developed by DotLine, are 4 x 400 mW violet laser (405nm). The 4 laser are driven from the DotLine software and electronic which is used in the normal CTP product range from DotLine.
Task for DotLine in this project was the development and realisation of the exposer system, optics and electronically components and to provide to the control software to expose metal foil.
The metal foil will be used as measuring tapes. Challenges were the new format and higher level in accuracy.
The foil will be exposed on both sides with the identical pattern with violet laser (405nm). The pattern will be exposed on both sides in coincidence, whereas an image control system checks the relative position between the XY coordinates of both sides.
The exposing of the foil is effected in Y direction due to a deflection of the laser beam with a special from DotLine developed polygon scanner and a modulation of the laser with up to 150 Mhz.
As in DotLine CTP³-devices common, the pattern as 1 BIT TIFF G4 files will be handled from the DotLine software EXCON. This software controls all processes and parameters.
The optical system exposes substrates up to 250mm width and a max. length of 5000mm. The requested accuracy in X direction (max. 5000mm) is 1µm/m and so multiple higher than in normal CTP applications.
The Image Processor Board controls the sensitive X-drive in subject to pattern image. In case of coincidence exposing of rear side the coordinates will be corrected with two translations (X,Y) next to the correction in rotation ?, so that a possible substrate displacement will be compensated.