Panasonic KX-FT21BX

KX-FT21LA
- 124 -
4-3. SCANNING BLOCK
The scanning block of this device consists of a control circuit and a contact image sensor made up of a celfoc lens array,
an LED array, and photoelectric conversion elements.
C79
J2
CN8
1
6
8
10
9
3
4
7
16 1 154
2
C4
R98
R79
205
8
9
168
SI
CLK
+5V
SEL
V.LED
G.LED
GND
GND
(CIS)
IC1
SIG
R81
R80
R82
AIN1
FTG
F1
CISSEL
173
CISON
IC7
+24V
+5V
LED ON
Circuit Diagram
When an original is inserted and the start button pressed, pin 154 of IC1 goes to a high level and the transistor inside IC7
turns on. This applies voltage to the LED array to light it. The contact image sensor is driven by each of the FTG-F1 signals
output from IC1, and the original image illuminated by the LED array undergoes photoelectric conversion to output an analog
image signal (AIN). The analog image signal is input to the system LSI (IC1) on ANA1 (pin 205 of IC1) and converted into
8-bit data by the A/D converter inside IC1. Then this signal undergoes digital processing in order to obtain a high-quality
image.