Read Sharp AL-840 (serv.man5) Service Manual online
No.
Parts
Note
Code
Signal name
Name
Type
Function/operation
Active condition
1
Scanner lamp
control PWB
control PWB
Drives the scanner lamp.
Maintains the lamp light quantity
at a constant level.
Maintains the lamp light quantity
at a constant level.
2
Scanner drive wire
Transmits the scanner motor
power to the scanner unit.
power to the scanner unit.
3
Scanner motor
Drives the scanner unit.
4
MHPS
MHPS
Scanner home
position sensor
position sensor
Photo
transmission
sensor
transmission
sensor
Detects the scanner home
position. By this signal the image
scanning operation is controlled.
position. By this signal the image
scanning operation is controlled.
HIGH (5V) when
the home position
is detected.
the home position
is detected.
5
Lens
Transfers the document image to
CCD.
CCD.
6
CCD
SENSOR
SENSOR
CCD OUT
CCD (Image)
sensor
sensor
CCD
Scans the document images
(photo signals) and converts
them into electrical signals.
(photo signals) and converts
them into electrical signals.
Digital signal
(8Bit)
(8Bit)
7
Scanner lamp
Radiates light to the document to
allow the CCD to scan the
document images.
allow the CCD to scan the
document images.
8
SL SENSOR
PDA/PDK
Scanner lamp light
quantity sensor
quantity sensor
Photo diode
Detects the scanner lamp light
quantity. This signal is inputted to
the scanner lamp control PWB to
control the scanner lamp drive
voltage to maintain a constant
level of light quantity.
quantity. This signal is inputted to
the scanner lamp control PWB to
control the scanner lamp drive
voltage to maintain a constant
level of light quantity.
Analog signal
(0
(0
∼
0.5V)
9
No. 1 mirror
Leads the document image to
CCD.
CCD.
10
No. 2 mirror
Leads the document image to
CCD.
CCD.
11
No. 3 mirror
Leads the document image to
CCD.
CCD.
<2> Scanner (writing) section
No.
Parts
Note
Code
Signal name
Name
Type
Function/operation
Active condition
1
SYNC
SYNC IN
Laser beam sensor
Bin diode
Detects the laser beam position.
By this signal the left image print
start position is controlled.
By this signal the left image print
start position is controlled.
LOW (0V) when
laser beam is
detected.
laser beam is
detected.
2
No. 1 mirror
3
No. 3 mirror
Leads the laser beam to the OPC
drum.
drum.
4
Second cylindrical
lens
lens
Corrects the laser beam
deflection by variations in the
scanning mirror angle. Corrects
the optical section dirt.
deflection by variations in the
scanning mirror angle. Corrects
the optical section dirt.
5
F
θ
mirror (No. 2
mirror)
Corrects the laser beam form and
pitch.
pitch.
6
Scanning mirror
(rotation mirror)
(rotation mirror)
Scans the laser beam and
performs imaging.
performs imaging.
7
No. 1 cylindrical
lens
lens
Adjust the direction of laser beam.
8
Laser diode
Generates laser beam. (Controls
ON/OFF for imaging)
ON/OFF for imaging)
2)
1) SYNC
8)
7)
6)
5)
4)
3)
5 – 6
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