Paper Loading Mechanism (Asf Unit) - Epson Stylus PHOTO 820 Service Manual

EPSON Stylus PHOTO 810/820
For your reference, the top or the end of a paper is usually detected with the HP/PE
sensor. In case that the HP/PE sensor cannot detect the top of a paper in the paper
loading sequence, the printer indicates the "Paper out error". If the HP/PE sensor
cannot detect the end of a paper in the paper feeding sequence, the printer indicates the
"Paper jam error". As for the details, refer to Chapter 3 "Troubleshooting".
Operating Principles

2.1.4.1 Paper Loading Mechanism (ASF unit)

The Paper loading mechanism consists of the Change lever in the Pump unit, the
Holder shaft unit (including the Clutch mechanism) and the ASF unit.
The Change lever and the Clutch mechanism play a major role in the Paper loading
mechanism as follows.
1. ASF home position detection function
The ASF unit on this printer does not have the ASF home position sensor. Instead
of the ASF home position sensor, the Change lever and the Clutch mechanism is
used to detect the ASF home position.
When the Change lever is set on the Clutch mechanism with the counterclockwise
rotation of the PF motor pinion gear, the ASF home position is detected by this
lever for the paper loading operation. In this time, the printer cannot load a paper
from ASF unit because the drive of the PF motor is not transmitted to the LD roller
shaft.
2. Paper loading function
When the Change lever is released from the Clutch mechanism with the clockwise
rotation of the PF motor pinion gear, the ASF home position detection function is
changed over to the paper loading function. Therefore, the printer can load a paper
from ASF unit because the drive of the PF motor is transmitted to LD roller shaft.
On this printer, the Paper return plate is built in ASF unit instead of the Paper return
lever. The LD pad is stacked on the Paper return plate, and it works with the tension
force of the Torsion spring 29.1 mounted on the ASF frame.
When an arc portion of the LD roller pushes down this plate into the ASF frame during
the paper loading sequence, a paper is loaded from the ASF unit. A cutout portion of
the LD roller releases this lever and this plate returns papers to the stand-by position for
next paper loading operation.
Following figures (refer to Figure 2-8/Figure 2-9) show you the ASF paper loading
sequence and the operation of each mechanism.
Overview
Revision A
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