Sharp AM 900 - Digital Office Laser Copier, Руководство по обслуживанию

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AM-900U
5 – 22
[5] Circuit description of CIS unit
1. CIS
CIS is an image sensor which scans the original paper in close contact
with the full-size sensor, being a color type with the pixel number of
5,148 dots and the scanning density of 600 dpi. It is composed of sen-
sor, rod lens, LED light source of Red, Green and Blue, Analog mem-
ory circuits and so on.
2. Block diagram
3. Waveform
3.1. Timing chart 1
1) CLK timing chart
2) Data output timing chart
After turning on the SP pulse, the analog output starts from the set-
ting up point of 64 clock pulse.
3.2. Timing chart 2
1) Reading color document
(*): The pulse width of CIS R LED/CIS G LED/CIS B LED are
adjusted automatically every scan, so it is a change.
2) Reading monochrome document
(*): The pulse width of CIS R LED/CIS G LED/CIS B LED are
adjusted automatically every scan, so it is a change.
Fig. 20
Fig. 21
Fig. 22
12 8 1 5 2
VLED VREF GND
4 6 7 3
NC
C
C
C
C
C
AO
R
R R
VDD SP CLK GND
9
B
10
LED GND
G
11
R
CIS UNIT
CISCLK
(CNCIS 7pin)
CISSP
(CNCIS 6pin)
(CNCIS 1pin)
4MHz
Approx. 3.3V
Approx. 1~1.5V
(White level)
Approx. 0.8V
(Offset level)
0V
0V
Ao
CISCLK
1 2 52 53 54 64 65 66
CISSP
VREF Output Perlod(52pixels)
1~52pixels
Analog Output Period
65~5212pixels
Dummy Output
53~64pixels
*1
Ao
Fig. 23
Fig. 24
1.7ms 1.7ms 1.7ms
CIS R LED(*)
(Q31-B)
CIS G LED(*)
(Q30-B)
CIS B LED(*)
(Q29-B)
CIS CLK
CIS SP
Ao
4MHz
4MHz
1.7ms 1.7ms 1.7ms
CIS R LED(*)
CIS G LED(*)
CIS B LED(*)
CIS CLK
CIS SP
Ao