Ricoh D124 - Page 118

118
MO-C1 Training
Slide 118
DRESS Sensor - 1
 Here is a closer look at the
DRESS sensor.
 It is mounted on the left side of
the carriage unit.
 The machine uses it for the
following:
 Paper width detection: The
sensor checks the right and
left edges of the paper on the
platen to check the size of the
paper. These readings are
used to position the image
between the right and left
margins.
 Paper registration (leading
edge and side-to-side) Every
time paper is fed to the
registration standby position, it
detects the leading edge of roll
paper. It also checks the right
edge of the paper twice to
correct paper skew.
 Skew correction: See above
 Dot position correction
 DRESS: Direct Realization Edge Scanning Sensor
 Dot position correction: Because the carriage unit is moving sideways during
printing, the ink drops do not fall vertically. In bi-directional printing (when the
data is printed both when the carriage moves right-to-left and left-to-right), it is
important to deposit the ink in the same position across the page when moving in
each direction. The DRESS sensor is used for this process. The amount of the
correction will also depend on the print head height setting, paper thickness, and
the speed of the carriage. This correction also handles color registration, to
make sure that the dots of each color ink are deposited in exactly the right
positions on the paper when making colors in the printout.