Epson Stylus PHOTO 950 Service Manual page 32

EPSON Stylus PHOTO 950
2.2.3.3 Carriage Lock
Mechanism
The carriage lock mechanism is used to prevent the printhead from becoming uncapped
for long periods as a result of vibration affecting the printer during transportation, and
also due to lack of care in handling by the user. If the printhead is left uncapped for
long periods, the ink on the surface of the printhead will gradually dry out, and this can
result in ink not being able to reach the nozzles. In addition to this, the nozzle holes can
become blocked with dried-out ink and normal head cleaning may not be able to
restore normal operation. The ink may also leak out at such times. In order to prevent
these things from happening, the printer locks the carriage unit in the following cases.
After the power turns off
If the power turns off while printing or other operations are in progress, the printer
is fully reinitialized and then the carriage is locked.
After the power turns on
After the power is turned on, timer cleaning is carried out automatically, and the
carriage is locked during this time.
Timer cleaning
1. The printer stores the date printing was last carried out in its EEPROM.
(The Stylus PHOTO 950 printer driver always appends the current date
reported by the computer's operating system to print commands when these
commands are sent to the printer.)
2. When printing is carried out at a subsequent time, the "previous printing
date" recorded in the EEPROM is compared with the date reported by the
computer's operating system that has been appended to the current print
command, and if the difference in the two dates is greater than a specified
length of time, timer cleaning is carried out.
After paper is ejected
If no print data is sent to the printer after the maintenance switch has been pressed,
the printer locks the carriage unit and switches to standby mode. However, if paper
is fed into the printer, the carriage is not locked.
OPERATING PRINCIPLES
<Left side>
Lock
Unlock
Figure 2-7. Carriage lock mechanism
Printer Mechanism
Revision A
Carriage lock lever
<Right side>
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