Sharp AR-M351U / AR-M451U (serv.man14) Service Manual ▷ View online
AR-M351U/M451U, AR-M355U/M455U MAINTENANCE AND DETAILS OF EACH SECTION 7 - 48
C. Operational descriptions
(1) CCD/lens unit
This machine employs the reduction optical-type line CCD (Charge Coupled Device) of scan resolution of 600dpi and 7450 pixels.
CCD scan is performed by shifting the scan positions sequentially by the carriage unit (lamp and mirror) scan or moving the document with
the SPF.
the SPF.
Lights reflected by the document are reflected by each mirror to form images on CCD elements through the reduction-type lens. The CCD
converts the optical energy into electrical energy (analog). (Photoelectric conversion)
converts the optical energy into electrical energy (analog). (Photoelectric conversion)
(2) CIS unit
The image sensor which scans back document images is attached to the SPF. The close-contact type image sensor (Contact Image Sen-
sor) with scan resolution of 600dpi and 7196 pixels is employed.
sor) with scan resolution of 600dpi and 7196 pixels is employed.
For the CIS to scan documents, the scan position is sequentially shifted by shifting the document by the SPF, and the LED light in the unit
is radiated to the back of the document, and photo energy is converted into electric energy (analog signal).
is radiated to the back of the document, and photo energy is converted into electric energy (analog signal).
No.
Name
Function
1
Copy lamp unit
Lights up to radiate documents. A xenon lamp (operating on 3.15KV) is employed.
2
Reflector
This mirror converges lights on documents.
3
No. 1 mirror
Secures the optical path between a document and No. 2 mirror.
4
No. 2 mirror
Secures the optical path between No. 1 mirror and No. 3 mirror.
5
No. 3 mirror
Secures the optical path between No. 2 mirror and the CCD.
6
CCD/Lens unit
The reduction optical type CCD (Charge Coupled Device) of 7,450 pixels is employed. The scan resolution
is 600dpi. Converts photo energy reflected by the mirrors into electric energy.
is 600dpi. Converts photo energy reflected by the mirrors into electric energy.
7
White balance sheet
Serves as the reference sheet of white for scanning with the CCD/Lens unit. If dust or dirt is attached to
this sheet, white streaks may be produced.
this sheet, white streaks may be produced.
8
Table glass
A document is set on this glass. The glass surface is coated for protection against static electricity.
A document is set to the top left corner.
A document is set to the top left corner.
9
SPF scan glass
The copy lamp unit is fixed, and a document is moved over this glass to scan line by line. The glass
surface is coated for protection against static electricity. If dust or dirt is attached to this sheet, black
streaks may be produced.
surface is coated for protection against static electricity. If dust or dirt is attached to this sheet, black
streaks may be produced.
10
Mirror home position
sensor (MHPS)
sensor (MHPS)
Detects the home position of the mirror base unit.
11
Scan motor
Drives the mirror base and the copy lamp unit.
12
DSPF white balance
sheet
sheet
Serves as the reference sheet of white for scanning with the CIS unit.
If dust or dirt is attached to this sheet, white streaks may be produced.
If dust or dirt is attached to this sheet, white streaks may be produced.
Lens center line
Focus point
LED PWB
CIS
CIS UNI
Auto-focus lens
Glass
AR-M351U/M451U, AR-M355U/M455U MAINTENANCE AND DETAILS OF EACH SECTION 7 - 49
(3) Image signal flow
The image signal converted into electric energy (analog signal) is
A-D converted on the CCD PWB. Image processes such as white
balance and shading correction are performed on the scanner
control PWB. The image signal is then sent through the mother
board to the MFP control PWB.
A-D converted on the CCD PWB. Image processes such as white
balance and shading correction are performed on the scanner
control PWB. The image signal is then sent through the mother
board to the MFP control PWB.
In the MFP control PWB, image process is performed according to
the setting content of the operation panel. The image data are
converted into laser lighting signals (VIDEO signals), and sent
through the mother PWB and the PCU to the LSU (Laser Scan
Unit).
the setting content of the operation panel. The image data are
converted into laser lighting signals (VIDEO signals), and sent
through the mother PWB and the PCU to the LSU (Laser Scan
Unit).
In the LSU, the VIDEO signals are converted into laser beams,
which are radiated onto the drum.
which are radiated onto the drum.
(4) Carriage (lamp unit) shift (scan) speed
The carriage scan speed depends on the copy magnification ratio.
Speed up to 171% = 110mm/s
Speed of 172% - 400% = 55mm/s
(5) Timing chart
Platen timing chart
SPF duplex timing chart
PSW
CCD
MHPS
MIMD
MM
Feed
Return
Home position
Home position
Scan
CCD
SPOD
CIS
SPPD4
SRRC
SPFM
1030mS
181mS
55mS
94mS
AR-M351U/M451U, AR-M355U/M455U MAINTENANCE AND DETAILS OF EACH SECTION 7 - 50
D. Maintenance and parts replacement
(1) Maintenance list
(2) Maintenance and parts replacement
Unit name
Part name
When
calling
100K 200K 300K 400K 500K 600K 700K 800K
Remark
Scanner
section
section
Mirror/Lens/Reflector/Sensors
❍
❍
❍
❍
❍
❍
❍
❍
❍
Table glass/Dust-proof glass/OC
❍
❍
❍
❍
❍
❍
❍
❍
❍
White reference glass
❍
❍
❍
❍
❍
❍
❍
❍
❍
Rails
✩
✩
✩
✩
✩
✩
✩
✩
Drive belt/Drive wire/Pulley
✕
✕
✕
✕
✕
✕
✕
✕
1
3
4
2
1
1
2
4
5
5
No.
Unit
Parts
a
Scanner unit
1
OC
❍
2
Dust-proof glass
❍
3
Table glass
❍
4
White reference glass
❍
5
Mirror
❍
6
Rails
✩
7
Drive wire
✕
8
Pulley
✕
9
Drive belt
✕
10
Scan motor
11
OC open sensor
12
Mirror home position sensor
13
Scanner control PWB
14
Scanner interface PWB
b
Lamp unit
1
Reflector
❍
2
Mirror
❍
3
Lamp
4
Inverter PWB
c
CCD lens
PWB unit
PWB unit
1
CCD lens
a-2
a-10
a-11
a-11
a-12
a-14
a-13
a-4
a-5
a-5
a-6
b-2
b-1
b
a-7
b-3
b-4
a-8
a-8
a-9
a-7
c
a-1
a-3
c-1
a-6
AR-M351U/M451U, AR-M355U/M455U MAINTENANCE AND DETAILS OF EACH SECTION 7 - 51
a. Scanner unit
a-1. OC
1) Remove the OC cover.
a-2. Dust-proof glass
a-3. Table glass
a-4. White reference glass
1) Remove the table glass holder and the white reference glass
holder, and remove the table glass and the white reference
glass.
glass.
a-5. Mirror
1) Remove the table glass.
2) Clean mirror.
a-6. Rails
1) Remove the table glass.
2) Grease up the rails.
a-7. Drive wire
a-8. Pulley
a-9. Drive belt
1) Remove the table glass.
2) Check the drive wire, pulley and drive belt.
a-10. Scan motor
1) Remove the scanner rear cabinet and the rear lower cabinet.
1)
1)
2)
3)
4)
3)
1)
2)
1)
3)
4)
4)
5)
6)
1)
1)
2)
3)
3)
4)
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