Table of Contents
Advertisement
F.
Document
Density
Measurement
3. Reading
Output
of AE Sensor
System
1. Outline
There
is an automatic
density
adjust-
ment (AE) system which
adjusts the DC
component
of the developing
bias to suit
the density of the original. If the density of
the original is more or less uniform, the AE
function varies the DC component
of the
developing
bias to suit the density of the
original, so that copies of the correct den-
sity will be made.
The AE sensor consists of a photodiode
(Q702)and
an operational amplifier(Q701).
If the strength of light striking the photo-
'
diode is high, the output voltage (AE) of the
amplifier will be small. If the amount of light
is small, the output voltage will be large.
The DC controller reads the output at a
certain
time
after
the zero-cross
signal
\t.py)
is received
from
the
DC power
2. Operation
The scanner
moves forward
approxi-
mately 70mm past the leading edge of the
original and stops momentarily.
The scan-
ning lamp goes ON for approximately
one
second, the image density is read by the AE
sensor, and the sensor output is interpreted
by the DC controller. The DC controller then
adjusts the DC component
of the develop-
ing bias accordingly.
66
Figure 3-20
,-
r_-------_______~
I--l
l-l
I
I
I
5v
-
I
I
I
'VR
I&
2s
I
304
b
I
AE
8
I
Q702"
15701-Z
5315-g
e
I
I
:
I
g
I
24V
I
I
AEB IAS
I
0
I
15701-l
5315-8
VR303
i
I
I
I
I-___--___________-l
i___
AE sensor
DC cantroller
Figure 3-21
-I
3 - 20
COPVAICHT
0
1900 CANON INC.
CANON NP-IOI5/IZI5S
RN.0
OCT. 1988 PAINTELI
IN JAMN (IMPRIM~
AU JAPAN)
Advertisement
Table of Contents
