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Z–M
[81 OPTICAL SYSTEM
1. General description
Light from the coPy lamp is directed by a reflector at
the original. The optical system of the Z-50
copier (fiber
optics)
directs
the light reflected
from the original
and
focuses the reflected image on the drum. The intensity
of the copy lamp is regulated by the exposure control
switch. A photo sensor in the optical system sensesthe
contrast of the original, automatically adjusting the copy
lamp intensity, The range of the exposure control is
regulated by the copy lamp control PWB. A thermal fuse
is mounted to the main reflector for overheat protection.
The Z-50 is a moving platen copier. The original table
moves the original over the stationary optical system.
The
table
movement
is accomplished through
two
clutches, the table feed clutch and the table return
clutch.
These are spring clutches controlled
by the
action of the table feed solenoid (TFS) and the table
return solenoid (TRS).
When the table is in motion an adjustable PS sensor
block mounted on the table lifts the paper stopper plate
which is used for registering the lead edge of the copy
paper to the lead edge of the image on the drum.
A SELFOC
lens is used so that the copy lamp light
(ima9e) reaches the drum surface in a short distance.
Moving table method is used for exposure.
Exposure is controlled by varying the copy lamp voltage.
A photosensor (diode)
is used in the optical system
for sensing contrast in the original. As the photosensor
receives light reflected from the original, the contrast of
the original is determined. The photosensor senses2mm
before the lens, to correct for any delay in the circuit or
copy lamp.
General block diagram
1$
t
2m
Original
Original table moving direction
/
—11
/
L
Auto exposure
sensor
p:.-k----
.arlatl
Copylamp intensitv
T
The exposure control lever
on the operation panel.
#
The sensor is installed in the center of the 50 mm slit so
that the contrast of the original is sensed within this 50 mm
area.
For the original out of this area, the automatic exposure
control function will not apply.
Rear frame side
.
@
Table forward moving direction
'
t
–u–
I
m
Original
set
reference line
Paper exit side
Sensing zone
mm
Paper entrv side
SELFOC lens
\
Sensor slit
Front
frame side
(Original table toP view)
2. Original table
The original must be placed to the right side edge of the
table on the rear frame side. An image loss appears in the
shadowed area due to paper separation.
Original set reference position
Table glass
71
Original lead edge
guide
,
..
-.,- ---
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