- HP Printer User Manual

ENWW Laser scanner unit 53
MFP unit explanation
*2 Light source
Conventionally, two parallel beams
were generated from two laser beams.
The laser diode adopted for this
machine can generate two beams using
a single chip, requiring neither
fine-adjustment prism nor beam
composition prism.
M15 (polygon) control
M15 (polygon) is driven by PMDB (polygon
drive board) and is controlled by PRCB
(printer control board).
1 Operation
a Explanation of operation
M15 is a 3-phase brushless DC motor
which is driven by the 3-phase bipolar
method. The current flowing through the
coil is switched according to the position
of the rotor detected by the position
sensor (magnetic sensor) in the motor.
This motor rotates the polygon mirror to
scan the laser beams from LDB (laser
driver board) in the axial direction of the
drum. Its rotation is held constant by
PLL control.
b Rotational speed
M15 is powered by 24 VDC and its
rotational speed is as follows:
2 Signals
a Input signals
1 POLM_LOCK (PMDB to PRCB)
This signal indicates the clock
synchronization state of M15
(polygon).
[L]: Synchronous (normal)
[H]: Asynchronous (abnormal)
b Output signals
1 POLM_CONT (PRCB to PMDB)
This signal turns on/off M15.
[L]: M15 on
[H]: M15 off
2 POLM_CLK (PRCB to PMDB)
This is a reference clock signal for
PLL-controlling M15 in PMDB.
Image write control
The analog image data from the CCD sensor
is A/D-converted by the ADB (A/D converter
board), then sent to the ICB (image control
board) for data processing. The processed
image data is converted into a laser beam
on the LDB (laser driver board), and then the
Rotational
speed
Linear speed 9055 9065
37,795 rpm 320 mm/s - normal
33,070 rpm 280 mm/s normal -
21,850 rpm 185 mm/s thick paper
PMDB
M15
PRCB
24V1
P.GND
POLM CONT
POLM CLK
POLM LOCK
DCPS
24V/1
5V/2
S.GND
P.GND
ICB
INDXSB
5V
SGND
/IND
SGND
/INDPR
LDB
GND
VIDEO2
/VIDEO2
GND
LPR5V
LD5V
LD5V
GND
VIDEO1
/VIDEO1
GND
/ENB1
/S/H1
/ALM1
GND
/ENB2
/S/H2
/ALM2
GND
DADI
DACLK
DALD
ADB
CCD
DCPS
24V1
5V2
S.GND
P.GND