Epson Stylus Color 640 Service Manual page 151

EPSON Stylus Color 440/640/740
5.2.2.9 Bi-D Adjustment
You perform this adjustment to correct differences in printing positions,
which is caused by slippage of printing timing in right and left directions
during the Bi-directional printing. Therefore, you are required to perform
this adjustment after performing the following operations.


Replacing the Print mechanism


Replacing the main board


Replacing the CR motor


Replacing the Carriage Assembly


Replacing g the Printhead
1. Apply the main menu (Figure 5-21). (See Section 5.2.2.2.)
2. By using the Up/Down arrow key, select Adjustment in the main
menu.
3. By using the Up/Down arrow key, select Bi-Directional
Adjustment in the adjustment menu. (See Figure 5-19.) The
following screen appears.
Figure 5-32. Bi-D Adjustment Menu
Chapter 5 Adjustment
4. By using the Up/Down arrow key, select Print the Bi-D adjustment
pattern on the screen, and the screen bellow appears.
Figure 5-33. Before Printing the Bi-D pattern
5. Press the Enter key. The printer starts printing a Bi-D adjustment
pattern. (See the sample pattern in the following page.)
NOTE:
As shown in the sample, gaps between passes are sometimes created
in different directions among patterns.
This unexpected change in direction is caused by an ink jet printer-
specific reason, which is an ink jet printer inevitably performs a
periodical cleaning specified by the flashing timer even during Bi-D
pattern printing, so that the printing direction suddenly changes.
However, this directional difference among Bi-D patterns should not be
considered, and you can always confirm and adjust the pattern correctly
by referring to gap amount only.
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