Ricoh A156 - Reproduction Ratio

4.4.3 Reproduction Ratio
The horizontal position of the lens has to be changed when a reproduction
ratio is selected. This is because the original is aligned at the rear left corner
but the copy paper is fed down the center.
When the reproduction ratio is changed, the vertical position of the lens is
changed. At the same time, the total focal length has to be changed to adjust
the image focusing. For this focal length change, the vertical position of the
3rd scanner is also adjusted.
The figure shows the vertical and horizontal position of the lens for ratios of
50, 100 and 200%.
Copy Paper
Original
200% 100%
50%
100%
50%
3rd Scanner Position
200%
Original Rear Edge
Horizontal
Position
Vertical Position
A156/A160/A162 2-44 STM