Service manual

2.1.4. Paper Handling Mechanisms
During normal operation, paper is fed into the printer, advanced to the specified position, and then ejected
from the printer. These paper-handling operations are performed by various paper handling mechanisms, such
as tractors, platens, rollers, and gears. This section describes the printer’s paper handling mechanisms.
2.1.4.1. Release Lever
The release lever is used to select friction for rear/front tractor feed or to release the paper for pull tractor
feed. Changing the release lever position moves the paper guide rollers, and the new lever position is
detected by 2 release switch sensors (RLSW1 and RLSW2). See the following table. The RLSW1 sensor is
located on the left side frame and the RLSW2 sensor is located on the inside of the right sub frame. Refer to
Figure 2-4.
Table 2-3. Release Lever Position
Release Lever
Position
Status of Paper Guide Rollers RLSW1 RLSW2
Friction mode The paper guide rollers are
pressed against the platen
Open Open
Rear push tractor
mode
The paper guide rollers are
separated from the platen
Closed Open
Front push tractor
mode
The paper guide rollers are
separated from the platen
Closed Open
Pull tractor mode The paper guide rollers and the
rollers for the lower paper guide
are separated from each other.
Closed Closed
Right Sub Fram
Lelease SW2
Tractor Clutch Cam
Release SW1
Platen
Left Frame
Open
Close
Figure 2-4 Release Switch
Operation Principles LQ-2070 Servcie Manual
2-4 Rev.A