Oce 3121 Technical & Service Manual page 285

<Document>
<Original>
The forward scanning
Main scanning
direction
--> direction
a b c
<Copy>
<Copy>
a b c
a b c
Shifting in the forward scanning
Shifting in Main Scanning Direction
direction
a b c
Not read
Not read
a b c The reading starts with this pixel
Reading starts
with this pixel.
<memory>
<Memory>
a b c
The image of a document may be shifted by combining shifts in the forward
scanning direction and shifts in the reverse scanning directions.
Corner Shift
1
The co-ordinates (X1, Y1) of the corner of a specific area is moved to any of
the four corners of the copy.
Centre Shift
2
The co-ordinates (Xm, Ym) are computed from the size of the area to be shift-
ed and the size of the copy, so that the margins at the top and the bottom and
the margins at the left and the right will be identical; the area will be moved to
X1 and Y1.
Xm= (Xmax–(X2–X1))/2, Ym= (Ymax–(Y2–Y1))/2
Note:
Free Shift
3
The co-ordinates (X1, Y1) of a specific area is moved to a specific point (Xp,
Yp).
ed.1
Shift in the reverse scanning direction
<Copy>
<Copy>
a b c
Principle
Principle : When data for a single scanning line is
Principle
Principle :
The position is varied, or the The position or the timing
at which the original
timing at which the document
illuminating system is started is
illuminating system is started
varied to shift the position of
is varied, to shift the position
the image.
of the image.
Main scanning derection
Shaft in main scanning direction
When data for a single scanning line is read
from line memory, reading starts with a midway
read from line memory, reading is started
pixel. Or, the timing at which the data of the
with a midway pixel or the timing at which
first pixel is read is delayed, thereby shifting
the data of the first pixel is read is delayed,
the pixel
thereby shifting pixel position.
--> The forward scanning
Main scanning direction
a b c
The reading starts with this pixel
Reading starts with this pixel.
a b c
a b c
08 Image processing 509
a b c
Not read
Not read.