Platen Gap Adjustment Mechanism - Epson LX-300+ Service Manual

LX-300+/1170
COLOR MECHANISM INITIALIZATION
The printer mechanism initializes when the power is applied or when recovering from the
energy saving mode.
o
Color mechanism initialization
Color mechanism initialization shifts color mechanism for the black ink area to be
at the home position. Color mechanism initialization shifts the carriage at the same
time to prevent the ribbon from hanging on the printhead.
When the buffer is cleared or when the printer is under the pause condition, the
color mechanism initializes and waits for the next printing command.

2.2.4 Platen Gap Adjustment Mechanism

This mechanism is to adjust the distance between the platen and the printhead (platen gap)
according to the paper thickness.
The following is the components of the LX-300+/1170 platen gap adjustment mechanism
and its explanation. (Refer to Refer to Figure 2-5.)
o
Carriage: Mounts the printhead.
o
Carriage guide shaft: Shifts the carriage horizontally.
o
Adjust lever and Parallelism adjust bushing:
Installed at the both ends of the carriage guide shaft
o
Platen gap detector (PG_SW)
Carriage guide shaft is eccentric toward the adjust lever rotating center. Due to this, when
rotating the adjustment lever back and forth, the printhead shifts toward and against the
platen to adjust the platen gap. When printing on thick paper such as postcards and
envelops, set the adjust lever over the 1st level. PG detector shifts the printer to the copy
mode from the printing mode. Printing speed will be lowered but it prevents wire from
breaking off.
Operating Principles
PLATEN GAP (PG_SW) DETECTOR
The following is PG_SW specification.
Table 2-9. PG_SW Detector Specifications
Item
Method
Switching rate
Switching mode
Parallelism adjust
bushing
PG_SW
Figure 2-5. Platen Gap Adjustment Mechanism
Printer Mechanism
Specification
Mechanical contact method
0.6 to 1.0 mA, 5 VD±5%
• PG=0: close
• PG=0-4: open
Adjust lever
Carriage guide shaft
Printhead
Platen gap
Adjust lever
Platen
Carriage
Carriage guide shaft
Revision C
Carriage
Parallelism adjust
bushing
Printer mechanism
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