Second Scanner Positioning - Ricoh FT4430 Service Manual

16 April '88

4. Second Scanner Positioning

Like the lens, the second scanner is positioned by counting the number of
steps from the home position. Second scanner home position is determined
by a HIGH to LOW to HIGH change at CN101-B4 of the main board.
Actually, as this machine has horizontal magnification adjustment by changing
the position of 2nd scanner drive pulley using SP Mode # 44, the home
position may be detected when the signal goes from HIGH to LOW by
calculating the adjusted magnification data.
When moving away from the home position, the second scanner drive pulley
[A] turns clockwise and moves the second scanner directly to the selected
position. However, when moving closer to the home position (pulley turning
counterclockwise), the second scanner overshoots the selected position by 5
steps and then returns to the selected position. This takes out any
mechanical play.
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