Canon 1000 Service Manual page 89

c. Original Position Identification
The size of an original and its position on the copyboard are identified.
(0,0)
X
1
Y
1
Original
Y
2
Y axis
(main scanning direction)
Figure 3-312
Figure 3-312 shows when a rectangular original is placed along the X axis (sub scanning direction) and
along the Y-axis (main scanning direction) on the copyboard. Figure 3-313 shows an original placed askew.
The underside of the copyboard cover is mirror-finished (preventing refraction of light) instead of coated
white as in the case of conventional copiers so that only the area where there is an original reflects the light
of the scanning lamp to the CCD.
• Area with an original
Figure 3-314
In general, most originals are white paper so that the area identified as being white during scanning can
be assumed to represent an original.
In other words, a rectangle (or square) whose diagonal line runs between coordinates Xmin/Ymin and
Xmax/Ymax is identified as an original.
If an original is placed at an angle as in the case of Figure 3-313, the rectangle whose diagonal line runs
between P and P will be identified as an original.
1 2
COPYRIGHT © 2001 CANON INC.
X axis (sub scanning direction)
X
2
Copyboard
Copyboard cover
Original
Copyboard glass
CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
3. OPERATION AND TIMING
(0,0)
X
1
P
1
Y
1
Y
2
Figure 3-313
• Area without an original
Figure 3-315
X
2
P
2
Copyboard
Mirror-finished surface
3-45