Ricoh LD013, Service Manual

Page: 217 / 513

IMAGE PROCESSING
B039/B040/B043 6-24 SM
Main Scan Magnification
Changing the scanner speed enables enlargement and reduction along the sub
scan direction. However, enlargement and reduction along the main scan direction
is handled by the IPU (KT-ONE) chip. The processing for main scan
enlargement/reduction is the same as in previous digital machines.
Mirroring for ADF Mode
When making copies using the ADF, the magnification circuit creates a mirror
image. This is because the scanning start position along the main scan direction in
ADF mode is at the opposite corner of platen mode.
In platen mode, the original is placed face down on the exposure glass. The main
scan start position is at corner [A], and the scanner moves down the page. In ADF
mode, the ADF feeds the leading edge of the original to the DF exposure glass.
Therefore as mentioned above, the main scan start position will be at the opposite
corner.
To create the mirror image, the IPU stores each line in LIFO (Last In First Out)
memory.
B039D404.WMF
[A]