FujiFilm CR-IR341 Service Manual page 113

C 1 2
ONTENTS
A/D converter
An analog image signal filtered is converted to a digital image by an A/D converter.
Image signal
+ 1V shift
A/D converter
Erasure level detection
An erasure level signal is outputted from the PMT08A board and inputted into the SCN08A
board, where a maximum value within one screen is detected. Because this signal is nonlin-
ear, it is eventually converted to a dose by software-based table correction.
The IP erasure time is determined according to this dose detected.
Reference voltage - 10V
Erasure level signal
Reference voltage - 2.5V
Shading correction signal
(Erasure level detection enable)
Erasure Level Detection Block Circuit
009-051-04
05.31.99 FM2460
3 4 5 6
ADC buffer
(PMT08)
Differential
input level
ZLCLKL
HSYNCL
generation
FCLKL
ERASENAL
CR-IR341 Service Manual
7 8 9
CLK
VINA
VINB
SENSE
+ 1V
VREF
3.3 F
0.1 F
X (- 10)
X (2.5)
X (- 2.5)
Analog
peak hold
shift
Latch Erasure
signal level data
latch
decoder
CLR
10
11
ADC
Reference voltages
for other ADC and DAC
- 10V
+ 2.5V
- 2.5V
A/D
conversion
8bit
CLK
8
P
Digital
comparator
Q
P>Q
Erasure level data
Buffer
MD - 50
11
74ALS574
FR1H0243.EPS
8
FR1H0244.EPS
MD - 50