Aps Control - Konica Minolta 7020 Service Manual

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APS Control

3
DCPS
APS detection is carried out at opening or closing of the
RADF cover or original cover, and is controlled by the
SCDB (scanner drive board) based on signals from the
APS sensors and CCD sensor. Related signals are
provided by PS14 (optics home position PS), PS15 (APS
timing PS) and by PS304 (DF open/close PS) on the
RADF.
1. Operation
a. APS detect operation
APS detection operation differs according to whether
operation is in platen mode or DF mode.
(1) Platen mode
Caution : In the case of machines other than
3
Size is detected by the combination of the ON/OFF
action of PS17 and PS18 (APS sensor 2) and the
detect signal from the CCD sensor on the ADB (A/D
conversion board).
PS17 and PS18 detect the original size in the sub
scanning direction, while the CCD sensor detects the
size in the main scanning direction.
5VDC
5VDC
SGND
SGND
12VDC
SGND
-12VDC
SGND
12VDC
CB
SGND
OPT_HOME PS14
5VDC
SGND
PS15
TIMING 1
5VDC
SGND
APS_DATA 1 PS17
5VDC
5VDC
5VDC
SGND SGND
APS_DATA 2 PS18
SGND
5VDC
SCDB
7020/25/30/35, the PS17 (APS sensor 1)
is not installed.
L1 is ON during APS detection, so that the illumina-
tion level (light or dark level) in the main scanning dif-
fers according to whether the original is present or
absent. To detect line width (main scanning width),
the CCD sensor detects the difference from sky shot
CCD
black level to paper edge white level at each side. If
the RADF is installed, original size detection in the
main scanning is reexecuted when PS304 (DF open/
ADB
close PS) comes ON, so as to confirm the original
size.
The two APS sensors (PS17 and PS18) each consist
of a photosensor and a LED. If the original is present
at the sensor position, the light generated by the LED
reflects from the original and is detected by the
photosensor
7020/25/30/35
7020/25/30/35
3
Exit
side
Other than 7020/25/30/35
Exit
side
(2) DF mode
Original size detection is carried out by ON/OFF
action of PS306 (original size detect PS 1), and
PS307 (original size detect PS 2), and by the
resistance level of VR301 (original size detect VR)
located in the RADF paper feed tray.
2-C-7
READ SECTION
PS17 PS18
PS18
: Photosensor
: LED