Ricoh A172 - Op-Port

10.3 OP-PORT
The OP-PORT 1 & 2 control the following:
1. Switches and LED Buzzer
2. Touch detection and Touch Point detection
3. Power Supply to the LCD
4. Contrast Adjustment
5. CFL (Cold Fluorescent Lamp) Power Supply inverter function
LED DATA
+5 V
+12 V
–12 V
SPEAKER
KEY DATA
MACHINE ID
CONTRAST
SWITCH
CONTROL 1
SWITCH
CONTROL 2
DRIVER
VFF
CFL
ADRFF
INT2
X DATA
Y DATA
Operation
Control
Board
BUZZER
OP-PORT 2
LED MATRIX
DIODE MATRIX
INVERTER
ANALOG
SW
COMPARATOR
AMPLIFIER: X
AMPLIFIER: Y
SW MATRIX
DECODER
DC/DC
CONVERTER
VR
REF VOLTAGE
GENERATION CIRCUIT
+12 V
+12 V
LED MATRIX
SW MATRIX
+5 V
X BIAS
Y BIAS
Y ANALOG
X ANALOG
LCD I/F
TOUCH
PANEL
LCD
HV
OP-PORT 1
A172/A199 2-38 SM