Home Position Detection; Shading Compensation - Konica Minolta magicolor 1690MF Service Manual

Theory of Operation Ver. 1.0 Nov. 2008
(2) DF mode
1. Press the start key, and the LED lights ON.
2. The exposure units moves from the home position (stand-by position ) reading the shading
sheet to make a shading compensation.
3. The exposure units moves to the stand-by position.
4. It moves to ADF reading position and original image reading starts.
5. After the reading completes, the exposure lamp lights OFF and it moves to the stand-by posi-
tion.
6. After it moves again to detect the reference position, it moves to the stand-by position and stops
there.
ADF Reading
position
Original reading
7.3.2

Home position detection

• Reading parts doesn't have a sensor to detect the home position of the scanner.
• Therefore the green LED lights on while the scanner is moving so that the reference
potions to be the boarder between the white and black of the shading sheet is searched
and the scanner moves from that position to the home position where locates far to the
given distance. Home position detection is conducted when power is On and the scan
completes its moving.
7.3.3

Shading compensation

• This shading compensation function compensates reading quality dispersion due to sen-
sitivity uniformity of image element of each CIS sensor or LED light distribution irregular-
ity.
• Shading compensation is carried out immediately before the original glass reading and
ADF original reading.
Home position
(Stand-by position)
Reference position
Shading
Reference position detection
7. Scanner section
A034T2C565AA
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