Sharp MX-1800N (serv.man23) Service Manual ▷ View online
MX-1800N SCANNER SECTION C – 1
MX-1800N
Service Manual
[C] SCANNER SECTION
1. Electrical and mechanism relation diagram
Signal
Name
Function/Operation
CLI
Scanner lamp
MHPS
Scanner home position sensor
Detects the home position of the copy lamp unit.
MIM
Scanner motor
Drives the copy lamp unit and the mirror base unit.
No.
Name
Function/Operation
1
Pulley belt
Transmits the scanner motor power to the pulley.
2
Pulley
Drives the scanner drive wire.
3
Scanner drive wire
Transmits the scanner motor power to the copy lamp unit and the mirror base unit.
4
Reflector
Condenses the copy lamp light.
5
No. 2 mirror
6
No. 3 mirror
7
Lens
8
CCD PWB
9
Idle gear
Transmits the scanner motor power to the belt.
CN3
501190-4017
CN1
501190-2017
CN148
501190-4017
CN147
501190-2017
CN137
CCD PWB
CCD_CLK1+
16
17
18
19
20
2
3
38
40
39
35
1
30
15
5
6
7
8
12
13
14
AD_MCLK-
AD_BLKCLP
SH_OUT-
AD_RDSI
CCD_CLK1-
AGND
AGND
TC-
TE-
AGND
AGND
AGND
AGND
TC+
TE+
AGND
AGND
34
36
37
32
33
CCD_SH
31
AD_MCLK+
AD_CLPIN
26
27
28
29
20
21
24
25
23
/RES_CCDAD
CCD_CLK2-
22
AD_SCLK
CCD_CLK2+
AD_WRSO
AGND
AD_SEN
18
19
A3.3V
CCD_RS-
/LVDS_STBY
AGND
15
16
17
CCD_CP-
AGND
CCD_CP+
A5V
AGND
AGND
CCD_RS+
11
12
13
14
7
8
9
10
1
2
AGND
AGND
A12V
5
6
3
4
AGND
9
10
11
4
AGND
AGND
CLKP1_OUT+
SH_OUT+
CLKP1_OUT-
TB+
TD+
TB-
TD-
AGND
AGND
TA+
TCLK+
TA-
TCLK-
AGND
AGND
AGND
AGND
AGND
A12V
CCD_CP-
AGND
CCD_CP+
A5V
AGND
AGND
CCD_RS+
A3.3V
CCD_RS-
/LVDS_STBY
AGND
/RES_CCDAD
AD_RDSI
CCD_CLK1-
CCD_CLK2-
AD_SCLK
CCD_CLK2+
AD_WRSO
AGND
AGND
AD_CLPIN
AD_MCLK-
AD_BLKCLP
AD_MCLK+
CCD_SH
AGND
AGND
CLKP1_OUT+
SH_OUT+
CLKP1_OUT-
SH_OUT-
AGND
AGND
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
CCD_CLK1+
23
AGND
AD_SEN
AGND
AGND
TC+
TE+
TC-
TE-
AGND
AGND
TB+
TD+
TB-
TD-
AGND
AGND
TA+
TCLK+
TA-
TCLK-
AGND
AGND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
1
2
3
4
MiM_A
MiM_B
MiM_/A
MiM_/B
MIM
1
2
3
MHPS
CLI
CN134
3
2
1
1
2
3
MHPS
D-GND
5V
MHPS
D-GND
5V
CL
INVERTOR
PWB
CN130
1
P-GND
P-GND
CL
24VPD
24VPD
5
4
3
2
5
P-GND
P-GND
CL
24VPD
1
2
3
4
24VPD
1
2
SCN-CNT PWB
8
4
3
7
5
6
2
9
MX-1800N SCANNER SECTION C – 2
2. Operational descriptions
A. Outline
This section functions and operates as follows:
1) The copy lamp radiates light onto the document, and the
1) The copy lamp radiates light onto the document, and the
reflected light is scanned by the three line (RGB) CCD element
and then converted into image signals (analog).
and then converted into image signals (analog).
2) The image signals (analog) are converted into 10bit digital sig-
nals by the A/D converter.
3) The image signals (digital) are sent to the image process sec-
tion (scanner control PWB).
B. Detail description
(1) Optical section drive
The optical section drive power is transmitted from the scanner
motor (MIM) through the belt, the drive pulley, and the wire to drive
the copy lamp unit and the mirror base which are attached by the
drive wires.
The scanner motor (MIM) is controlled by the drive signal sent from
the scanner control PWB.
motor (MIM) through the belt, the drive pulley, and the wire to drive
the copy lamp unit and the mirror base which are attached by the
drive wires.
The scanner motor (MIM) is controlled by the drive signal sent from
the scanner control PWB.
(2) Scanner lamp drive
The scanner lamp (CLI) is driven by the scanner lamp drive voltage
generated in the CL inverter PWB according to the control signal
sent from the scanner control PWB.
generated in the CL inverter PWB according to the control signal
sent from the scanner control PWB.
(3) Image scan/color separation
Light is radiated to a document by the scanner lamp, and the
brightness of the reflected light is received by the three line (RGB)
CCD element and converted into (analog) image signals.
Each color component of RGB is separately extracted from the
document image by the three lines (RGB) of the CCD elements.
The red CCD extracts the red components from the document
image, the green CCD the green components, and the blue CCD
the blue components. This operation is called Color Separation.
The CCD element, appeared as one unit, but has three separate
rows of CCD elements drive each for (RGB).
Scanning of a document in the main scanning direction is per-
formed by the CCD elements. Scanning of a document in the sub
scanning direction is performed by shifting the scanner unit position
with the scanner motor.
Document images are optically reduced by the lens and projected
to the CCD elements.
Scanning resolution is 600 dpi.
brightness of the reflected light is received by the three line (RGB)
CCD element and converted into (analog) image signals.
Each color component of RGB is separately extracted from the
document image by the three lines (RGB) of the CCD elements.
The red CCD extracts the red components from the document
image, the green CCD the green components, and the blue CCD
the blue components. This operation is called Color Separation.
The CCD element, appeared as one unit, but has three separate
rows of CCD elements drive each for (RGB).
Scanning of a document in the main scanning direction is per-
formed by the CCD elements. Scanning of a document in the sub
scanning direction is performed by shifting the scanner unit position
with the scanner motor.
Document images are optically reduced by the lens and projected
to the CCD elements.
Scanning resolution is 600 dpi.
(Image data per 1 line)
(4) Image signal A/D conversion
1)
Each image signal (analog) of RGB is converted into 10bit dig-
ital signal by the A/D converter.
Each color pixel has 10bit information (256 gradations).
ital signal by the A/D converter.
Each color pixel has 10bit information (256 gradations).
2)
Each 10bit digital image signal of RGB is sent to the image
process section.
process section.
(5) Zooming operation
Zooming in the sub scanning direction is performed by changing
the scanning speed in the sub scanning direction.
Zooming in the main scanning direction is not performed optically
but by the image process technology (software).
the scanning speed in the sub scanning direction.
Zooming in the main scanning direction is not performed optically
but by the image process technology (software).
B
R
G
R
G
B
Red component of
image data
image data
Blue component of
image data
image data
Green component of
image data
image data
R
G
B
CCD PWB
Transfer IC
B ADC
B
B
3
CCD
B
IC
G
IC
R
IC
G ADC
R ADC
R
R
G
G
MX-1800N SCANNER SECTION C – 3
3. Disassembly and assembly
A. Optical system
(1) Scanner unit
1)
Remove the upper cabinet rear cover and the upper cabinet
rear.
rear.
2)
Remove the table glass and the SPF glass.
3)
Remove the upper cabinet right and the upper cabinet left.
4)
Disconnect the connector and remove the snap band.
5)
Remove the screws, and remove the scanner unit.
a. Table glass /
b. SPF glass
1)
1)
Remove the SPF glass (A). Remove the glass holder (B) and
the table glass (C).
the table glass (C).
Unit
Parts
Maintenance
(1)
Scanner unit
a
Table glass
{
b
SPF glass
{
c
Lens
{
d
CCD
{
e
Reflector
{
f
Mirrors
{
g
Lamp
{
h
CL inverter PWB
i
CCD unit
j
Scanner motor
k
Scanner home position
sensor
sensor
l
Original cover SW
m
Document detection light
receiving PWB
receiving PWB
n
Document detection light
emitting PWB
emitting PWB
o
Rails
✩
p
Drive wire
q
Drive belt
(1)-a
(1)-o
(1)-b
(1)-p
(1)-h
(1)-g
(1)-p
(1)-f
(1)-d
(1)-f
(1)-e
(1)-c
(1)-o
(1)-m
(1)-n
(1)-l
(1)-j
(1)-k
(1)-q
(1)-i
(1)
1
2
3
A
B
C
MX-1800N SCANNER SECTION C – 4
c. Lens /
d. CCD
1) Remove the glass holder and the table glass.
2) Remove the dark box cover (A) and the lens cover (B).
1) Remove the glass holder and the table glass.
2) Remove the dark box cover (A) and the lens cover (B).
3) Clean the lens (A) and CCD (B).
e. Reflector /
f. Mirrors
1) Remove the glass holder and the table glass.
2) Shift the lamp unit and the mirror unit.
3) Clean the reflector and No. 2 and 3 mirrors.
1) Remove the glass holder and the table glass.
2) Shift the lamp unit and the mirror unit.
3) Clean the reflector and No. 2 and 3 mirrors.
4)
Shift the lamp unit to the right end. Loosen the screws and
remove the wire.
remove the wire.
5)
While rotating the lamp unit, lift the lamp unit. Remove the har-
ness holder and the flat cable. Remove the lamp unit.
ness holder and the flat cable. Remove the lamp unit.
6)
Clean the mirrors.
g. Lamp /
h. CL inverter PWB
1)
1)
Remove the table glass and the SPF glass.
2)
Remove the lamp unit.
3)
Disconnect the connector and remove the lamp.
A
B
A
B
2
2
1
3
2
1
3
2
1
Display
