Label Gap/Black Mark Sensors - Intermec EasyCoder PC4 Service Manual

5.8 Label Gap/Black Mark Sensors

Description
Replacement
Intermec EasyCoder PC4—Service Manual
The receiver part of the label gap sensor and the black mark sensor are
fitted on the same circuit board. The purpose of the label gap/black mark
sensors is to control the printer's stepper motor to feed the media properly
in relation to the gaps between labels, detection slots, or black marks at the
back of the media. It also detects out-of-media conditions. The label gap/
black mark sensor PCB is fitted below a window in the floor of the media
cavity using two screws. It is connected to JP13 on the main board.
To allow the use of parallel labels fitted on the same liner, the sensors are
placed slightly to the right of the center-line (as seen from the front) as fol-
lows:
- Label Gap Sensor
- Black Mark Sensor
The board has one LED emitter and two receivers. The black mark sensor
emitter shines upwards. The black mark sensor receiver detects light
reflected by the back side of the media. No light received is interpreted as a
black mark.
The label gap sensor receiver detects light from the emitter board in the
print frame (see Chapter 4.7) that passes through gaps in the media or
through the liner between labels. No light received is interpreted as a label
(or similar) and light received is interpreted as a gap. This function can be
reversed using the OS command, see ESim v6.xx, Programmer's Reference
Manual.
The sensitivity of the label gap sensor is adjusted automatically when enter-
ing the Test Mode (see Chapter 10.2). At the same time, the label length is
determined.
• Remove the main board from the base frame moulding.
• Disconnect the cable from JP13 on the main board.
• Adjust med media guides for maximum media width.
• Remove the screws that hold the sensor board.
• Install new board in reverse order.
4.5 mm 0.177 inches
10 mm 0.394 inches
Chapter 5—Base Frame
43