Sony UP-897MD - Monitoring of Door Sensor; Monitoring of Head Temperature Sensor; Control of Head Fan Motor (for Head Cooling)

3-2-4. Monitoring of Door Sensor
The door position is read using an optical door position
sensor (photo-interrupter PH202 on the SE-768 board) by
1C202.
State of door position sensor
Position 1C202 (pin 87) or State
CN204 (pin 2)
DOOR_SENSE
CLOSE H The door is closed.
OPEN L The door is opened.
3-2-5. Monitoring of Paper Sensor
Whether thermosensible paper is correctly set in this unit is
detected using two pairs of optical paper sensors (photo-
transistors Q102 and Q302 on the KY-572 and SE-769
boards) and read using IC202.
iy
State of paper sensor
1C202 (pin 43) or 1C202 (pin 175)or State
CN201 (pin 7) AD3. = CN205 (pin 2) AD5
(PAPER_SENSE) (PP_EMP_SENSE)
H H Paper
L L No paper
H L No paper (Paper
exists in an eject
port and does not
exist in a tray.)
L H No paper (Paper
does not exist in
an eject port and
exists in a tray.)
3-2-6. Monitoring of Head Temperature
Sensor
The change in the resistance value of a thermistor in a
thermal head is converted into a voltage and read using
1C202. The A/D-converted voltage value corrects the
density (gamma), controls the head cooling fan motor, and
discriminates whether to clean the head.
3-2-7. Control of Head Fan Motor (for Head
Cooling)
A head fan motor operates when IC202 controls driving
transistors (Q607 and Q608). The head fan motor is turned
on when the head temperature is more than approximately
62°C (cooling) or during printing.
Operation of head fan motor
1C202 (pin 94) HEAD _FAN Operation
L OFF
H ON
UP-897MD