Advertisement
II. EXPOSURE SYSTEM
A. Changing the Reproduction
Ratio
The reproduction
ratio across the drum
is varied
by changing
the position
of the
lens. It is moved by the lens drive system.
The reproduction
ratio around
the drum is
varied
by changing
the
speed
of the
scanner.
Figure
3-10
shows
how
the
position of the lens is varied to change the
reproduction
ratio across the drum
D'RECT
v
ENLARGEMENT m&
Figure 3-10
The scanner drive system changes the
reproduction
ratio
around
the drum
by
varying
the speed at which mirror 1 moves
relative to the peripheral
speed of the drum.
(The scanner is mirror 1 plus the scanning
lamp.)
The mirror
speed
is faster
than
the
drum peripheral
speed for REDUCTION
and
slower for ENLARGEMENT.
No&',
,(.
('(
;I'_ (i'"'(_ ,:,
';
2,'. ';
1. " The relative
~ospion
of the
mikw
if+
'_,
+t 'changed
to varj, thd, repryductiot-',
:
ratio..
' 17"
,,
4
'I
'.2.
For
OHEC?
copying,
the q&e&of
the.mi,rror
is' the, same
a&the'
Cl
perip_heral speed ofthe drum. ::
't* 3'1 ',I ,':
,',
"" , :
,'/P
B. Lens Drive System
1.
Outline
,-
The lens
is moved
by the scanner
motor (M2). Normally, the coupling gear is in
its upper position, and connects the scanner
motor
to the scanner
drive
capstan.
To
move the lens, the lens solenoid (SL2) goes
ON, causing the coupling gear to disengage
from the scanner capstan gear and engage
with the lens capstan
gear. The lens is a
"floating
element"
type.
In operation,
the
relative
position
of the
lens
elements
(individual
lenses)
changes,
and the focal
length changes as a result, but the changes
are to optimize
lens sharpness
for each
reproduction
ratio,
not to make
the lens
function
as a zoom lens. (The lens should
not be dismantled.)
When the scanner motor rotates (CW),
the lens
will
be moved
to the
left
(for
ENLARGEMENT)
by the capstan and cable.
When the cassette
size is changed
or
when the copier is in the REDUCE
mode,
the blank exposure
shutter moves in relation
to the distance over which the lens travels,
thereby
blanking
out the width
corres-
ponding
to the reproduction
ratio;
see
p. 3-31.
The DC controller
indicates
'E210'
on
the control panel in response
to an error in
the lens drive system.
-.
Advertisement
