Ink Mark Sensor - Epson 3800 - Stylus Pro Color Inkjet Printer Service Manual

EPSON Stylus Pro 3800/3800C/3850

2.7 Ink Mark Sensor

This printer is equipped with the ink mark sensor functioning as multi sensors.
The sensor, located on the bottom of the carriage unit, is a diffuse reflective
photointerruptor that is comprised of a light emitting part (white LED) and a light
receiving part (photoreceiver). The white LED emits light against the paper or
dedicated print pattern printed on paper and the photoreceiver reads the reflected light.
According to the reflected light read by the receiver, the printer calculates correction
values to perform proper corrective actions.
The Ink mark sensor is used for the following adjustments.
† Auto Bi-D Adjustment
The sensor scans predetermined patterns printed for the adjustment and detects the
highest density pattern among them. According to the detected result, the printer
calculates Bi-D correction values automatically.
† Auto Uni-D Adjustment
The sensor scans predetermined patterns printed for the adjustment and detects the
highest density pattern among them. According to the detected result, the printer
calculates Uni-D correction values automatically.
† Auto Nozzle Check
The sensor scans a nozzle check pattern. The pattern is printed with the all nozzles and
each nozzle prints one block. If there is a clogged nozzle, the corresponding block will
not be printed and detected by the sensor, and a head cleaning is performed
automatically.
OPERATING PRINCIPLES Ink Mark Sensor
Revision A
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