Ricoh D124 Detailed Descriptions Manual page 121

2. The DRESS sensor (1) (functioning here as an image registration sensor) is
comprised of a sensor with an LED (2) and a receptor (3).
 The strength of the reflection of the light from the paper can vary depending on
the surface of the paper.
 Printing problems can occur if the same threshold value of reflectivity is used
for every type of paper.
 For this reason, different threshold values of reflectivity are assigned for
different types of paper to compensate for any difference in the reflectivity of
their surfaces.
The readings of the DRESS sensor for the left and right margins are used to
determine the horizontal placement of the image on paper. This can be adjusted with
SP1002 (Print Position Adjustment). This adjustment determines where the moving
carriage starts and ends printing with every horizontal pass across the paper.
 A larger setting moves the image to create a wider left margin.
 A smaller setting moves the image to the create narrow left margin.
Image position adjustment in the main scan (horizontal) direction
Margin (white space)
Detailed Descriptions 115 D124