Skew Detection - Fujitsu ULTIMA90 Maintenance Manual

Drive gear
APTC motor
( pulse motor)
<The paper surface detection switch on the left side of the card guide>
The ceramic chip is pressed by the paper surface during print head approaches. And then panel keyboard SW is
pressed by lever. The spring is mounted in order to acquire the proper load to detect the paper surface.
Spring

5.2.1.6 Skew detection

Skew is detected by two sensors provided on the card guide in the carriage unit when a cut sheet is loaded.
The card guide has two sensors: TOFL and TOFR. If a detection difference between the two sensors when the
top end of paper passes them is too large, paper is ejected to the front.
Skew detection is valid only when a cut sheet is fed manually. It is invalid when a cut sheet is fed from the CSF
(front or rear) or continuous forms are fed.
Figure 5.7 APTC approach and escape mechanism
SW holder
Panel keyboard SW
Ceramic chip
Figure 5.8 APTC sensor structure
Pivot of lever
Lever
Card Guide (Aluminum)
134
SS gear
( Stay shaft)
APTC HP SW
Paper surface