Circuit Diagram (4/13) - Oki OKIFAX4550 Maintenance Manual

3.4 46F Circuit Diagram (4/13)
1. Block diagram
46F-PCB circuit diagram (4/13) shown the consists of the following functions:
• IC6 (A/D converter)
• Connector CN5 that provides an interface between 46F board and CIS (contact image
sensor).
Figure A.9 (1/3) shows the related signals and block diagram of CIS.
2. Function
One-line picture data is read in the sequence from the scanning unit (CIS) as SIG signal (analog
data) to A/D converter (analog/digital converter) of IC6. After conversion from analog data to 6-
bit digital signal (SDT2 - SDT7) under the control of IC6, this picture data is sent to IEXSEED300
(Scanning control LSI) of IC16. Here, the picture data undergoes various kinds of picture
processings.
Sensor interface signal output from IEXSEED300
• LEDON
• SNSCLK : Scanning sensor drive clock (1.25 MHz)
• MISP
• ADCLK
3. Signal timing
Figure A.9 (2/3) shows the signal timing of contact image sensor, and Figure A.9(3/3) shows the
signal timing of A/D converter.
IC16
LEDON
TR505/TR1
IEXSEED
300
SDT2 - SDT7
PDCK (1.5 MHz)
IC6
A/D converter
Figure A.9 (1/3) Related Signals and Block Diagram of CIS (contact image sensor)
41309401TH Rev.4
: LED on/off control signal
: Scanning synchronous signal (2.5 msec)
: Sampling clock for A/D converter (1.25 MHz)
R51
CN5
Transistor
VLED
GLED
MISP
SIG
+5V
-8V
0VA
CIS (contact image sensor)
VLED (+24V)
10
9
GLED
6 MISP
8 DCK
1
SIG
3
+5V
4
-8V
2,5,7
0VA
LEDs array
Rod lens array
sensor
2592 bit
(216 mm)
Shift register &
analog switches
Amplifier
313 /