Main Scan Magnification - Ricoh B202 Service Manual

Main Scan Magnification

The ASIC2 chip on the IPU board handles reduction and enlargement in the main
scan direction while the machine changes the scanner speed to reduce or enlarge
the original in the sub-scan direction.
• Scanning and laser writing are done at a fixed pitch (CCD elements cannot be
squeezed or expanded).
• Imaginary points are calculated. These correspond to a physical enlargement or
reduction.
• Image density is then calculated for each of the imaginary points based on the
image data for the nearest two true points.
• The calculated data then becomes the new (reduced or enlarged) image data.
NOTE: The actual calculations for main scan magnification use the polynomial
convolution method. This mathematical process is beyond the scope of this
service manual and will not be covered here.
SM 6-33
IMAGE PROCESSING
B202/B178/B180