UBI EasyCoder 601 XP – Service Manual Ed. 1
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Chapter 7 Transfer Ribbon Mechanism
7.4 Ribbon End Sensor
Description
The ribbon end sensor is a photoelectrical device that detects
whether there is any thermal transfer ribbon in the printer or not. It
is fitted to the centre-line wall immediately behind the print
mechanism by means of a single #T10 Torx screw. The sensor
assembly consists of a sensor with cable and connector, and a
combined mirror/bracket.
Working Principles
The ribbon end sensor works like this. A narrow beam of light is
emitted from the sensor and is either absorbed by the black transfer
ribbon, or reflected back by a mirror to a receiver in the sensor. The
software compares the signal from the sensor with the printer's
setup in regard of media type in order to avoid printing on the wrong
type of media:
Set up
Detection
Error
Thermal transfer media
Ribbon
OK
Thermal transfer media
No ribbon
Error 1027 Out of transfer ribbon
Direct thermal media
No ribbon
OK
Direct thermal media
Ribbon
OK
The ribbon end sensor is connected to P52 on the CPU board.
Sensor
Mirror
Bracket