Colorimetric Calibration (Color Id) Overview - Epson Stylus Pro 7400 Service Manual

EPSON Stylus Pro 7400/7800/9400/9800

2.5 Colorimetric Calibration (Color ID) Overview

This printer employs "Colorimetric Calibration (Color ID)" to correct unit-to-unit
variations in color.
"Colorimetric Calibration (Color ID)" corrects not only the weight of ink droplets
which differs according to the characteristic of individual printhead but variable factors
such as drive circuit and voltage, which provides a higher-accuracy calibration.
OVERVIEW
1. Printing/ Measuring the color of a correction pattern.
The calibration is performed by printing a correction pattern with a completed product
and measuring the color of the pattern using a calibrator.
2. Writing the correction value.
Write the correction value that was calculated from the value obtained by color
measurement to the NVRAM on the main board.
3. Reflecting the correction value.
The printer driver reads the correction value stored in the NVRAM during printing,
and correct the dot generation amount for each dot size in the print data.
Operating Principles
Main Unit
Drive Control
Correction of weight of
Colorimetric Calibration (Color ID) Overview
Printhead Main Board
Characteristic of Variation of elements in
individual printhead the drive control circuit
for printhead
Colorimetric Calibration
Circuit for
Printhead
Correction of dot generation amount
ink droplets
Printing
Result
Figure 2-21. Colorimetric Calibration (Color ID) Image
Revision B
Supply Board
Variation of
reference
voltage for
individual
printhead
(Color ID)
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