Sharp AL-800 (serv.man3) Service Manual ▷ View online
(2) Printer mode
P1)
Print data (compressed data) are sent from the host. (Image
data (Data 1 – 8)
data (Data 1 – 8)
P2)
Print data are developed by the ASIC and the line memory and
converted into the full dot image data and sent to the data
select section. (Image data)(VIDEO)
converted into the full dot image data and sent to the data
select section. (Image data)(VIDEO)
P3)
The data are sent through the data select section to the scan-
ner (writing) section. (image data) (V DATA)
ner (writing) section. (image data) (V DATA)
CCD PWB
DATA FLOW DIAGRAM
CCD
DRAM
I/F
CPU BUS
analog
image data
image data
image data
image data (V DATA)
image data
A/D
image data(LD)
CPU
H8S
H8S
ROM
RAM
EEPROM
SRAM
32kbitx8
SRAM
32kbitx8
serial data
(OP DATA/KIN1/KIN2)
DRAM
16Mbit
(SC only)
DRAM
16Mbit
(SC only)
DRAM
16Mbit
(SC only)
serial data (EEPD)
(CCD OUT)
(CCDD0~7)
image data
(Data1~8)
(VIDEO)
serial data
(SDATA)
Amplifier
MCU PWB
Image process ASIC
Data select
ICU PWB
LSU unit
Laser
Operation panel
Image
process
C1
C2
C3
P2
ASIC
P1
P3
C4
1 – 4
3. Operations of each section
A. Paper feed, paper transport section
(1) Outline
The paper feed tray contains about 200 (250) sheets of paper.
The paper is passed to the transfer section by the paper feed roller.
The paper feed operation is controlled by the paper feed roller clutch
and the paper feed roller clutch solenoid. The paper feed clutch
employs the mechanical spring clutch.
and the paper feed roller clutch solenoid. The paper feed clutch
employs the mechanical spring clutch.
Paper mis-feed and paper jam are detected by the paper empty
sensor and the paper entry sensor. The paper size (width) is detected
by the paper size (width) detector to prevent toner from attaching to
the area over the paper width.
sensor and the paper entry sensor. The paper size (width) is detected
by the paper size (width) detector to prevent toner from attaching to
the area over the paper width.
(2) Major parts
2)
1) PE SENSOR
3)
4)
5) PUS
6)
7) PIN SENSOR
8)
11)
4)
9) PAPER SIZE SW
6)
12)
13)
14)
12)
8)
13)
15)
17)
16)
16)
18)
10)
19)
19)
1 – 5
No.
Parts
Note
Code
Signal name
Name
Type
Function/operation
Active condition
1
PE SENSOR
PEMP IN
Paper empty
detector
detector
Photo
transmission
sensor
transmission
sensor
Detects paper on the paper tray.
LOW (0V) when
paper is detected.
paper is detected.
2
Paper guide
Adjust the paper width.
3
Paper feed tray
Sets the print paper. (Capacity:
XXX sheets)
XXX sheets)
4
Paper release
lever
lever
Put this lever straight to set
paper to release paper feed. Put
this lever down to enable paper
feed.
paper to release paper feed. Put
this lever down to enable paper
feed.
5
PUS
PUS
Paper feed clutch
solenoid
solenoid
Controls (on/off) the main motor
drive for the paper feed roller.
drive for the paper feed roller.
6
Paper feed
release lever
release lever
When the paper feed lever is put
straight, this lever releases
paper feed solenoid drive. This
partially reduces stress to the
paper feed roller clutch in
removing paper.
straight, this lever releases
paper feed solenoid drive. This
partially reduces stress to the
paper feed roller clutch in
removing paper.
7
PIN SENSOR PIN
Paper in detector
Photo
transmission
sensor
transmission
sensor
Detects whether the fed paper is
transported to the transfer
position or not. By the timing of
this detector signal, the relative
positions of paper and print
image are controlled.
transported to the transfer
position or not. By the timing of
this detector signal, the relative
positions of paper and print
image are controlled.
LOW (0V) when
paper is detected.
paper is detected.
8
Paper feed roller
Feeds paper.
9
PAPER SIZE
SW
SW
PAPER SIZE
IN
IN
Paper width
detector
detector
Mechanical
switch (Micro
switch)
switch (Micro
switch)
Detects the paper width. This
signal controls the laser beam
radiation area.
signal controls the laser beam
radiation area.
LOW (0V) when
the max. width is
detected.
the max. width is
detected.
10
Paper pressure
plate
plate
Presses paper onto the paper
feed roller.
feed roller.
11
Paper pressure
spring
spring
Presses paper onto the paper
feed roller.
feed roller.
12
Paper separator
Separates paper in paper feed
operation.
operation.
13
Paper feed clutch
Mechanical
spring type
clutch
spring type
clutch
Controls ON/OFF of the paper
feed roller. (The paper feed roller
is driven by the paper feed clutch
solenoid and the main motor.
feed roller. (The paper feed roller
is driven by the paper feed clutch
solenoid and the main motor.
14
Paper feed clutch
lever
lever
Driven by the paper feed clutch
solenoid to control ON/OFF of
the paper feed clutch. Prevents
against reverse rotation of the
paper feed roller.
solenoid to control ON/OFF of
the paper feed clutch. Prevents
against reverse rotation of the
paper feed roller.
15
Paper feed clutch
joint
joint
Links the paper feed roller and
the paper feed roller clutch.
the paper feed roller clutch.
16
Paper feed clutch
sleeve
sleeve
Controls ON/OFF of the paper
feed roller. (The paper feed roller
is driven by the paper feed clutch
solenoid and the main motor.)
feed roller. (The paper feed roller
is driven by the paper feed clutch
solenoid and the main motor.)
17
Paper feed clutch
spring
spring
Transmits the paper feed clutch
rotation to the paper feed clutch
sleeve.
rotation to the paper feed clutch
sleeve.
18
Paper feed clutch
gear
gear
Transmits the main motor power
to the paper reed roller.
to the paper reed roller.
19
Paper separater
spring
spring
Applies a proper pressure to the
paper separater.
paper separater.
1 – 6
(3) Operation
a. Block diagram
b. Operation
*
The main motor is a 4-phase stepping motor of 2-phase excite-
ment bipolar system, which serves as the drive source of the paper
feed and transport system.
ment bipolar system, which serves as the drive source of the paper
feed and transport system.
*
The pickup solenoid operates on 24V and turns ON/OFF paper
feed operation.
feed operation.
*
The following sensors are used.
Paper empty sensor (transmission photo transistor):
It is installed on the LSU PWB and is used to detect whether there is
paper in the paper feed tray or not.
paper in the paper feed tray or not.
Paper entry sensor (Transmission photo transistor):
This sensor is used to detect the paper feed timing of next paper (in
pre-feed) and to make synchronization between paper transport and
image forming on the drum. It is also used to detect a paper jam.
pre-feed) and to make synchronization between paper transport and
image forming on the drum. It is also used to detect a paper jam.
Paper exit sensor (Transmission photo transistor):
This sensor is used to detect that paper is discharged.
It is also used to detect a paper jam.
*
Paper release lever
The paper release lever is used to fix or release paper. To release
paper, pull the lever toward you as shown in the figure below. To fix
paper, push the lever forward. The lever mechanism is as shown
below.
paper, pull the lever toward you as shown in the figure below. To fix
paper, push the lever forward. The lever mechanism is as shown
below.
PUS
MEN
ASIC
(IC8)
MCU(PCU)PWB
MMT0
MMT1
CPU
(IC5)
1
2
2
3
4
4
MA
MA-
MA-
MB
MB-
MB-
CN804
1
2
2
3
+5V
POUT
POUT
GND
+24V
CN805
1
2
+24V
PUS
PD801
+5V
PIN
PD802
+5V
POUT-
CN7
9
PE
CN9
PE
LSU PWB
+24V
9 PE
PD601
CN601
High voltage power PWB
Paper pickup
solenoid
solenoid
Main motor
Paper feed
roller
roller
Paper entry
roller
roller
Paper exit
roller
roller
Paper empty
roller
roller
Motor
driver
driver
(Paper release)
(Paper fixed)
1 – 7
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