Epson LQ-570e - Printer Mechanism; Printhead; Paper Feed Mechanism; Carriage Movement Mechanism

EPSON LQ-580 Revision C
O
perating Principles Printer Mechanism
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2.2 Printer Mechanism
This printer mechanism consists of Printhead, Paper feed mechanism, Carriage movement
mechanism, Tractor feed mechanism, Platen gap adjustment mechanism, Ribbon feed
mechanism, PF motor, CR motor, detectors, and so on.
2.2.1 Printhead
The printhead prints data from the control board on paper using the ink ribbon. The
printhead is mounted on the carriage unit.
2.2.2 Paper Feed Mechanism
The paper feed mechanism picks up paper and transports it to the printhead, then ejects it
step by step or continuously driven by the PF motor. PF motor drives the paper feed
mechanism gears and the platen roller. The top of form and paper out condition are detected
by front and rear PE detector, respectively.
2.2.3 Carriage Movement Mechanism
The carriage movement mechanism carries the carriage unit left and right along the CR
guide shaft and mechanism frame and stops it at any position for printing. It is driven by the
torque sent from the CR motor via the timing belt. Home position is detected by the HP
(home position) detector at power on and CR motor phase changing timing.
2.2.4 Tractor Feed Mechanism
The tractor feed mechanism feeds continuous paper to the printhead and ejects it. The
torque from the PF motor is transferred to the tractor unit via the release mechanism in the
paper feed mechanism. The release mechanism switches the PF motor torque between cut
sheet feeding and continuous paper feeding by the release lever. This printer is equipped
with several tractor feeding methods (front / rear push tractor feeding, front / rear push &
pull tractor feeding and front / rear pull tractor feeding), which is selected according to the
tractor unit setting positions and the lever positions. The tractor detector detects the release
lever setting position in cut sheet feeding or continuous paper feeding.
2.2.5 Platen Gap Adjustment Mechanism
The platen gap (the gap between the platen and the printhead) adjustment mechanism
consists of CR guide shaft, parallelism adjustment bushing, PG adjust lever and PG
detector. PG adjust lever is attached to the left side of the CR guide shaft. The bushings are
attached to the both sides of the frame. As the both sides part of CR guide shaft is eccentric
toward external form of it, printhead approaches or recedes from the platen roller to turn the
PG lever forward or backward. PG detector detects PG lever position. If the lever is set 2nd
and more position, the printer gets into copy mode.
2.2.6 Ribbon Feed Mechanism
The CR motor drives the ribbon feed mechanism via the timing belt. The ribbon feed
mechanism has the sun and planetary gear system. No matter the carriage unit is driven left
and right, the ink ribbon is driven in one direction.