FujiFilm CR-IR341 Service Manual page 111

C 1 2
ONTENTS
SCN08A Board
The SCN08A board, which is located between the MTH board and scanning optics/scanner
unit, controls each I/O of the scanning optics/scanner unit in accordance with an instruction
from the MTH board.
Polygon driver/laser/HV control is performed so that a start-point detection signal detected
by the SYN08A board and a leading-edge detection signal detected by the SED08A board
are acquired as sync signals to control the image acquisition timing. Furthermore, as its self-
diagnostic function, image quasi-read control is implemented to generate a quasi-read LED
output voltage.
For image acquisition, an analog image signal is inputted from the PMT08A board (log amp
board), and after shading correction and filtering, it is analog-to-digital (A/D) converted for
output to the IMG08A board (image processing board) as digital image data.
Image signal acquisition
A block diagram, from input of an analog signal from the PMT08A board (log amp board) to
A/D conversion for output to the IMG08A board (image processing board), is illustrated
below. The digital image data acquired is transferred to the IMG08A board at high speed.
Quasi-reading
Input buffer
PMT board
Image Signal Acquisition Block Diagram
Image acquisition timing is shown below.
OFCLKL
OLCLKL
OLCLKL
Enlarged view
OPCLK
Image data [10 : 0]
009-051-04 009-051-04
05.31.99 FM2460 (1) 05.31.99 FM2460
3 4 5 6
Filtering
Shading correction
A/D conversion
Laser
Accelerated phosphorescence light is guided to PMT
by the light-collecting guide
PMT output signal in main-scan direction
D1 D2
CR-IR341 Service Manual
7 8 9
Output buffer
IMG board
Light-collecting guide
Scan over IP
FR1H0240.EPS
D3 D4
10
FR1H0241.EPS
MD - 48
MD - 48