Epson R1800 - Stylus Photo Color Inkjet Printer, Service Manual

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EPSON Stylus Photo R1800/R2400 Revision B
Adjustment Adjustment 147
5.2.4 Colorimetric Calibration
This calibration is performed to compensate the ink discharge amount when
the following parts are replaced:
„
Print Head
„
Main Board
„
PS Board
The following tools are used for this adjustment:
„
Photo paper (A4 or letter-size): 1 sheet (for printing Calibration Chart)
„
Plain paper (A4 or letter-size): 1 sheet (for checking the nozzles)
„
PC (OS: Windows XP/Me/2000/98)
The following drivers must be installed on the PC:
•
Printer Driver for Stylus Photo R1800
•
USB Driver for the Calibrator
(Interface other than USB are not available.)
„
Calibrator (GretagMacbeth Eye-One with a UV filter)
•
Scanning ruler (supplied with the Calibrator)
•
Calibration plate that contains a white reference tile
(Calibrator accessory)
„
Colorimetric Calibration Tool for Stylus Photo R1800 (program)
„
Black paper (A4 size or larger) (A paper printed in solid black can also
be used.)
Figure 5-19. The Calibrator and the Accessories
The following tool is used to mail the Calibration
Chart when measuring color at a place different
from the repair work site.
„
Clear file
„
Plain paper (A4 or letter-size) : 1 sheet
5.2.4.1 Overview of the Colorimetric Calibration
†
Purpose
Measuring the color of the ink discharge amount information and
registering/controlling this information improves calibration accuracy and
ensures consistent color quality.
„
To reduce unit-to-unit and mode-to-mode variations in color.
„
To improve the accuracy of the Ink Counter.
The Color ID can improve the Ink Counter accuracy, which reduces the
running cost of ink.
†
Colorimetric Calibration Technology
„
The Principle
The ink discharge amount characteristic of a printer is measured by
measuring color difference (L*a*b*) of a printed chart with a calibrator.
Created Color ID information based on the obtained L*a*b values is
stored on the printer. When printing, the printer sends the Color ID to
the printer driver to compensate the number of ink droplets (dot
generation rate) for each of nine
1
different sized droplets of each color.
This method allows mass-produced printers to provide consistent print
quality reducing unit-to-unit variation.
Example: Compensation of Ink Amount Ejected from a Print Head
(dot generation rate)
•
When the standard printer generates ten dots.
If the ink discharge amount is insufficient by 10%, this is compensated by
generating 11 dots.
Note 1: Three different sized droplets (small, medium, large) for each of three
waveforms (VSD1, 2, 3)
„
Head ID
In the conventional color calibration with a Head ID, the print head
characteristics (weight of discharged ink) are measured and
compensated. The following shows the correlation between
conventional Head ID adjustment and Colorimetric Calibration.
Calibrator Scanning Ruler
White
Reference
Tile
Calibration Plate
C H E C K
P O I N T
As color measurement is performed with the fully assembled
product, the electrical characteristics which are unique to
each Main/Power Board are also compensated in addition to
the Print Head.
Clear file