Konica Minolta magicolor 1690MF Service Manual - Page 50

DF mode, Home position detection, Shading compensation

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magicolor 1680MF magicolor 1690MF COMPOSITION/ OPERATION Theory of Operation Ver. 1.0 Nov. 2008 7. Scanner section (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. Home position (Stand-by position) ADF Reading position Reference position Shading Original reading Reference position detection A034T2C565AA 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 irregularity. • Shading compensation is carried out immediately before the original glass reading and ADF original reading. 23

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Theory of Operation
V
er. 1.0
N
ov. 200
8
7. Scanner section
23
magicolor 1680MF
magicolor 1690MF
COMPOSITION/
OPERATION
(2)
DF mode
1.
Press the start key, and the LED lights O
N
.
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.
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.
A034T2C565AA
Home position
(Stand-by position)
ADF Reading
position
Reference position
Shading
Original reading
Reference position detection