Epson 3880 - Stylus Pro Color Inkjet Printer, Service Manual, Page: 60 / 306

Epson Stylus Pro 3800/3800C/3850/3880/3885/3890 Revision C
OPERATING PRINCIPLES Colorimetric Calibration (Color ID) Overview 60
2.10 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 depending on the individual characteristics of print head but also variable
factors such as drive circuit and voltage. This enables a higher-accuracy calibration.
OVERVIEW
1. Printing/ Measuring the color of a correction pattern
A correction pattern printed by a completed product is used for the calibration.
A calibrator is used to perform the color measurement of the printed pattern.
2. Writing the correction value
Correction values are automatically calculated based on the result of the color
measurement and stored in the NVRAM on the main board.
3. Reflecting the correction value
Every time the printer makes a print, the printer driver reads out the correction
values from the NVRAM. Each ink droplet weight and the number of ink droplets
for each dot are corrected according to the information.
Figure 2-35. Colorimetric Calibration (Color ID)
Print Head Main Board
Power Supply
Board
Main Unit
Variation of elements on
the print head control
circuit
Variation in
voltage
applied to
print head
Individual characteristic
of print head
Colorimetric Calibration
(Color ID)
Correction of the number of ink droplets
Drive Control
Circuit for
Print Head
Correction of
ink droplet weight
Printout