Sharp FO-165, Service Manual

Page: 64 / 112

[5] Circuit description of CCD PWB
The CCD board picks up optical information from the document, con-
verts it into an electrical (analog) signal and transfers it to the control
boad.
(1) Block diagram
Fig. 8
(2) Description of blocks
1. CCD
The TCD1208P is a highly sensitive charged coupled image sensor
that consists of 2160 picture elements.
Receiving four drive signal (
φ
T,
φ
2,
φ
1,
φ
R) from the control board, the
tranferred photoelectric analog signal OS is impedance converted,
and the signal VO, is supplied to the control board.
2. Waveforms
1.
φ
1,
φ
2 (=
φ
1) signals within the control board.
Fig. 9
Φ
T
Φ
1
Φ
2
+5V
GND
Φ
R
VO
OUTPUT CIRCUIT
(emitter follower)
OS
CCD
TCD1208P
Approx. 5V
0V
Approx. 5V
0V
Approx. 5V
0V
Approx. 100mV
OS
φ
R
φ
1 (=
φ
2)
φ
T
1.67
µ
Sec
5m Sec
1.67
µ
Sec
2. OS
φ
UX-177H
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