Oki B 4100 Maintenance Manual page 407

A3.2.5 M17 Circuit Diagram (Page 5/17)
1. Block diagram
The circuit diagram shown on page 5/17 consists of the following function:
• IC6 (A/D converter) and amplifier
• 30 V/24 V conversion circuit
• Connector CN10 that provides an interface between M17 board and CIS (contact
image sensor).
Figure A3.2.5 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 via amplifier. After conversion from
analog data to 6-bit digital signal (SDT2 - SDT7) under the control of IC6, the picture data is sent
to EXSEED (scanning control LSI) of IC20. Here, the picture data undergoes various kinds of
picture processings.
Sensor interface signal output from EXSEED.
• LEDON: LED on/off control signal
• PDCK : Scanning sensor drive clock (1.25MHz for ODA/833KHz for INT'L)
• MISP
• ADCLK: Sampling clock for A/D converter (1.25MHz for ODA/833KHz for INT'L)
IC20
LEDON
EXSEED
SDT2 - SDT7
IC6
A/D converter
30 V/24 V conversion
30 V
circuit
Figure A3.2.5 Related Signals and Block Diagram of CIS (contact image sensor)
40055101TH Rev.4
: Scanning synchronous signal (2.5 msec)
M17
CN10
Transistor
VLED
10
TR9/TR10
9
GLED
MISP 6
PDCK (1.25MHz/833KHz)
8
SIG
1
Amplifier
3
+5 V
4
-8 V
2, 5, 7
0 VA
24 V
CIS (contact image sensor)
VLED (+24 V)
GLED
Rod lens array
MISP
Shift register & analog switches
DCK
SIG
Amplifier
+5 V
-8 V
0 VA
LEDs array
sensor
1728 bit (216 mm)
407 /