Original Exposure System (Ir7200); Outline - Canon iR8500 Service Manual

3 Original Exposure System (iR7200)

3.1 Outline

The major functions of the original exposure system are as follows:
Item
Scanning lamp
Original Scanning
Scanner position detection
Reproduction ratio (zoom)
Scanner drive control
Lens
Scanning lamp activation
Original size detection
COPYRIGHT © 2001 CANON INC.
Xenon lamp
In book mode: by moving the scanner.
With ADF in use: by stream reading while holding the No. 1
mirror base fixed in position.
By scanner HP sensor (PS102)
[1] Using the Copyboard: 25% to 400%
• In main scanning direction, image processing is per-
formed by the controller unit.
• In sub scanning direction, the speed of the No. 1 mirror
base is changed (50% or higher), in addition, the image
data is processed by the controller unit (lower than
50%).
[2] Using the ADF: 25% to 200%
• In main scanning direction, the image data is processed
by the controller unit.
• In sub scanning direction, the speed at which the origi-
nals are moved is changed (50% or higher), in addition,
the image data is processed by the controller unit
(lower than 50%).
The No.1/No.2 mirror base is controlled by means of a step-
ping motor (M3).
Lens array (fixed in position)
[1] Turned on by an inverter circuit.
[2] Monitored for errors.
[1] In book mode, by a reflection type sensor in sub scan-
ning direction; by a CCD in main scanning direction.
[2] With the ADF in use, by the ADF.
2000 2000 2000 2000 CANON iR8500/7200 REV.1 AUG. 2001
CHAPTER 2 NEW FUNCTIONS
Description
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