Ricoh D124, Detailed Descriptions Manual

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Detailed Descriptions 9 D124
DRESS Sensor
The DRESS (Direct Realization Edge Scanning Sensor) sensor is mounted on the left
side of the carriage unit (shown above with the left cover the carriage unit removed). It
performs these functions:

Paper width detection . The sensor checks the right and left edges of the paper
on the platen to check the size of the paper.

Image registration . Detects the leading edge, right edge, and left edge of the
paper so the machine can position the image on the paper.

Skew correction . Checks and corrects skew at the right edge of the paper. If the
edge is skewed more than
±
10 mm, the machine rewinds the paper onto the roll.

Dot position correction (color registration) . The carriage moves across the
paper during printing, so the ink drops cannot fall vertically. The readings of the
DRESS sensor are used to adjust the timing of the piezo-electric elements in the
print heads that release the ink. Timing is adjusted for the height of the carriage
(and print heads), paper thickness, speed of the carriage, and print mode
(uni-directional or bi-directional).