Oki OKIOFFICE 84 Service Manual page 388

A3.1.4 R51 Circuit Diagram (Page 4/12)
1. Block diagram
The circuit diagram shown on page 4/12 consists of the following functions:
l
IC6 (A/D converter)
l
Connector CN5 that provides an interface between R51 board and CIS (contact image sensor).
Figure A3.1.4 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 IOGA4
l
LEDON : LED on/off control signal
l
SNSCLK : Scanning sensor drive clock (1.25 MHz)
l
MISP : Scanning synchronous signal (2.5 msec)
l
ADCLK : Sampling clock for A/D converter (1.25 MHz)
Service Guide OKIOFFICE 84
Chapter A Board Descriptions
Page: 232