Epson DLQ-3000 Minerva+, Service Manual, Page: 129 / 189

DLQ-3000+
Rev. A
4-2
4.2 Adjustment
4.2.1 Platen Gap (PG) Adjustment
Platen gap adjustment involves the following operations:
‰
CR guide shaft parallelism adjustment
‰
Platen gap reference value measurement and write operation
‰
CR guide shaft parallelism adjustment
The parallelism adjust bushing rotates eccentrically toward the center of the location hole
in the right side frame, and it makes the right end of the CR guide shaft move toward or
from the platen roller as the parallelism adjust bushing rotates. The parallelism
adjustment is made to set the CR guide shaft parallel to the platen roller by turning the
parallelism adjust bushing. With this adjustment, the printhead moves in parallel with the
platen roller.
R i g h t S i d e F r a m e
C R G u i d e S h a f t
( L o w e r C R G u i d e S h a f t )
P l a t e n R o l l e r
P a r a l l e l i s m A d j u s t B u s h i n g
L o c a t i o n h o l e i n t h e r i g h t s i d e f r a m e
C R G u i d e S h a f t
( L o w e r C R G u i d e S h a f t )
Figure 4-1. CR Guide Shaft Parallelism Adjustment
‰
PG reference value measurement and write operation
The PG reference value is measured by inserting 3 different thickness gages (0.39 mm,
0.55 mm and 0.72 mm) between the printhead and the platen roller. The PG reference
value measurement operation is required to compensate for physical unevenness which
is unique to each printhead. The PG reference value write operation writes the following
values into the EEPROM using the adjustment program:
‰
Value “
α
” (1-digit number marked at the head nose side.)
‰
3 values (
β
1,
β
2 and
β
3) measured with the thickness gauges
Perform CR guide shaft parallelism adjustment first, then the PG reference value
measurement and write operation.