Real time registration in lithography system

A device for measuring reference points in real time during lithographic printing, comprising:

• a light source providing an exposure beam;
• a light modulator modulating the exposure beam according to an exposure pattern;
• a measurement system comprising a camera, the measurement system configured to define at least one camera area of interest to optimize fast camera data transfer and to measure a position of a number of alignment marks previously arranged on a substrate;
• and
• an exposure optical system comprising a control unit, the exposure optical system delivering the modulated exposure beam as an image provided by the light modulator onto the substrate;
• wherein the exposure system control unit is configured to:
• calculate the orientation of the substrate based on the position of the alignment marks simultaneously to delivering the modulated exposure beam, and
• control the delivering of the modulated exposure beam relative to the calculated orientation of the substrate.