A correction file enables compensation of system-specific optical errors.
Barrel and pin-cushion distortion are produced by the arrangement of the mirrors in the scan head and characteristics of the F-Theta objective. This distortion lends itself well to calculation, and can therefore be compensated. A correction file can be used to position the focus of scan heads that employ a variable focus unit (e.g. a varioSCAN) in place of an F-Theta objective. Here, a table is generated that couples the set values in the image field with the control values. Correction files are utilized by the RTC control board before data is sent to the scan head.
The highest precision is attained with a correction file generated by an image field calibration that takes all static errors into account.