- HP Printer User Manual

ENWW Scanner section 49
MFP unit explanation
a Original read
The original read timing is as follows:
1 Platen mode
After lapse of the specified interval
since the exposure unit turned PS61
(scanner HP) off.
2 ADF mode
After lapse of the specified interval
since the original's leading edge
turned PS306 (original conveyance)
on.
APS control
The APS method used in the platen mode is
different from that used in the ADF mode.
The signal read by the APS sensor or ADF's
original size detection sensor is processed
by ICB (image control board) via SCDB
(scanner drive board).
1 Operation
a APS detection
1 ADF mode
The paper size is detected according
to the combination of on/off states of
PS309 (original size/2) and PS310
(original size/1) of the ADF's original
feed tray and the resistance value of
VR301 (original paper size).
2 Platen mode
The paper size is detected according
to the combination of on/off states of
PS63 (APS/1), PS64 (APS/2), and
PS65 (APS/3) and the signal read by
the CCD sensor. PS63 to PS65 are
used to detect the original size in the
sub-scanning direction and the CCD
sensor is used to detect the original
size in the main scanning direction.
Relationships between sensors and paper
sizes are as follows:
z ON
{ OFF
b APS detection timing
The APS detection timing differs
between the platen mode and DF mode.
1 ADF mode
When the ADF mode is selected or an
original is set on the ADF original feed
tray, APS detection takes place using
PS51
SCDB
S.GND
APS TIM
5V
PS63
S.GND
APS.1
APS 5V
PS64
S.GND
APS.2
APS 5V
PS65
S.GND
APS.3
APS 5V
ICB
APC CONT
COVER SIG
APS.1 SIG
APS.2 SIG
APS.3 SIG
S.GND
SIZE PS L
5V
PS309
PS310
VR301
PRCB
SIZE PS L
APS TIMING
DCPS
24V1
5V2
S.GND
P.GND
SIZE PS S
SIZE ANA
S.GND
SIZE PS S
5V
A.GND
SIZE ANA
3.3V
Sensor
Paper size
PS65 PS63 PS64
Min. size {{{
B5R z{{
B5 {{{
B4 zzz
A4R zz{
A4 {{{
A3 zzz
8.5 by 11R z{{
8.5 by 11 {{{
8.5 by 14 zzz
11x 17 zzz
LED
PS65
PS63
PS64
Paper exit side
Photo sensor